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STUDY DESIGN A retrospective study. OBJECTIVE To determine the incidence of pedicle screws close to vital structures and to identify patient or curve characteristics that increase the risk of screw misplacement. SUMMARY AND BACKGROUND Most pedicle screw misplacements are asymptomatic, thus they are frequently undetected. This study identifies the rate of screw placement in proximity to vital structures using postoperative computed tomography scans. METHODS A total of 2132 screws in 101 patients, who underwent posterior spinal fusion for spinal deformity, were reviewed. Screws adjacent to great vessels and viscera were identified and evaluated. Patients with screws at risk (group B) were compared with patients without screws at risk (group A). Patient and curve characteristics were analyzed to determine whether a correlation with screw misplacement exists. RESULTS A total of 40 at risk screws (∼2%) were identified in 25 patients (∼25%). These 40 screws were in proximity to the aorta (31), left subclavian artery (1), esophagus (3), trachea (3), pleura (1), and diaphragm (1). Of the 31 screws close to the aorta, 10 screws in 6 patients were impinging or distorting the aortic wall. One hundred percent of misplaced screws were in the thoracic spine, 50% were misplaced laterally, 50% were 35 mm long, 57.5% were in pedicles with normal morphology, and 75% were in curves between 40 and 70 degrees. Median screw misplacement rate was 10% in group A and 13% in group B. Adjusted for age and preoperative Cobb angle, patients with a higher misplacement rate were more likely to have screws adjacent to vital organs [adjusted odds ratio: 1.06 (95% confidence interval, 1.01-1.13), P=0.033]. CONCLUSIONS Although only a small number of screws were at risk, they occurred in a large percentage of patients (25%). A single at-risk screw causes a significant complication for the patient. Postoperative imaging beyond routine x-rays may be needed to detect at-risk screws in asymptomatic patients.

Background To evaluate the incidence and characteristics of venous thromboembolic events (VTE) associated with pregnancy in a contemporary patient series. Methods We performed a retrospective review of 33,311 deliveries between June 2003 and June 2008. Patients with objective documentation of a VTE during pregnancy or the 3-month postnatal period were identified from hospital discharge International Classification of Disease Codes edition 9 codes. Diagnosis of deep venous thrombosis (DVT) was largely made by a Duplex ultrasound, whereas pulmonary embolism (PE) was diagnosed by a computerized tomographic angiography (CTA). Results Of 33,311 deliveries during the study period, 74 patients (0.22%) had a VTE. There were 40 incidents of DVT (0.12%) and 37 of PE (0.11%). DVT involved the iliac veins (6), the femoral or popliteal veins (16), the infrapopliteal veins (17), and the axillary vein (1). Most (57.5%) of the DVTs involved the left lower extremity. Thirty-eight (51.6%) of the VTEs occurred in the postnatal period, and of those 33 (87%) occurred within 1 week of delivery. Most of the postnatal VTEs (68%) were seen in patients who underwent a cesarean section. Among patients with VTE during pregnancy, there were 28% in the first trimester, 25% in the second, and 47% in the third. Events were distributed among maternal age groups as follows: 26% aged 13-24, 50% aged 25-34, and 24% aged 35-54. Of the 35 patients tested for a hypercoagulable disorder, 12 were found to have a positive test result. Five (6.8%) of these 74 patients had a prior history of VTE, with two having a hypercoagulable disorder. In addition, 45 of the 74 patients were on oral contraceptive therapy or received hormonal stimulation therapy before pregnancy. Patients with a VTE during pregnancy were treated with low molecular weight or unfractionated heparin. Most postnatal patients were treated with subcutaneous low molecular weight heparin and coumadin. Six inferior vena cava filters were placed in patients with bleeding complications as a result of anticoagulation. There were no deaths during the study period. Conclusions Comparing our results with historic controls (DVT: 0.04-0.14% and PE: 0.003-0.04%), the incidence of DVT in pregnancy has not changed significantly. We note, however, that the incidence of pulmonary embolus in our series is higher than previously reported. CTA has been used for the diagnosis of PE since the past decade. The increase in the rate of PE in the current series may be because of the higher sensitivity of CTA when compared with previous diagnostic modalities.

Objectifs Evaluer l’incidence et les caracteristiques des evenements thrombo-emboliques veineux (ETV) associes a la grossesse dans une serie contemporaine. Methodes Nous avons effectue une revue retrospective de 33 311 accouchements survenus entre juin 2003 et juin 2008. Les patientes ayant presente un ETV au cours de la grossesse ou des trois mois suivant la periode post-natale ont ete identifiees a l’aide de l’International Classification of Disease Codes a la sortie de l’hopital. Le diagnostic de thrombose veineuse profonde (TVP) a ete majoritairement effectue par echographie Doppler alors que celui d’embolie pulmonaire (EP) a ete effectue par angio-tomodensitometrie (ACT). Resultats 74 patientes (0,22%) ont presente un EVP a l’issue des 33 311 accouchements effectues durant la periode d’etude. Il y a eu 40 TVP (0,12%) et 37 EP (0,11%). Les TVP ont interesse les veines iliaques (6), femorales ou poplitees (16), sous-poplitees (17) et axillaires (1). La plupart (57,5%) des TVP a interesse le membre inferieur gauche. Trente-six (51,6%) des ETV sont survenus au cours de la periode post-natale et parmi eux 33 (87%) sont survenus dans la premiere semaine suivant l’accouchement. La majorite des ETV post-nataux (68%) a ete identifiee chez des patientes ayant eu une cesarienne. Les patientes presentant un ETV au cours de la grossesse etaient dans 28% des cas dans leur premier trimestre, 25% dans le second et 47% dans le troisieme. Les evenements etaient distribues selon l’âge maternel de la maniere suivante : 26% des patientes âgees de 13 a 24 ans, 50% des patientes âgees de 25 a 34 et 24% des patientes âgees de 35 a 54 ans. Douze parmi 35 patientes ayant eu la recherche d’un desordre de la coagulation ont eu un test positif. Cinq (6,8%) de ces 74 patientes avaient un antecedent d’ETV, deux d’entre elles ayant une hypercoagulabilite. De plus, 45 des 74 patientes recevaient une contraception orale ou avaient recu une stimulation hormonale avant la grossesse. Les patientes presentant un ETV au cours de la grossesse ont ete traitees par heparine de bas poids moleculaire ou heparine non fractionnee. La plupart des patientes ayant un evenement post-natal ont ete traitees par heparine de bas poids moleculaire sous-cutanee et par Coumadine. Six filtres de la veine cave inferieure ont ete places chez des patientes ayant des complications hemorragiques du traitement anticoagulant. Il n’y a eu aucun deces durant la periode d’etude. Conclusions Comparee aux donnees historiques (TVP : 0,04-0,14% et EP : 0,003-0,04%), l’incidence des TVP au cours de la grossesse ne s’est pas modifiee significativement. Nous observons cependant que l’incidence d’embolie pulmonaire dans notre serie est superieure a celle precedemment rapportee. L’ACT a ete utilisee pour les diagnostics d’EP au cours de la derniere decennie. L’augmentation du taux d’EP dans la serie presente pourrait etre liee a une plus forte sensibilite de l’ACT comparee aux plus anciennes modalites d’imagerie diagnostique.

Objectif Le pontage composite sequentiel femoro-popliteo-distal est une option valable pour le traitement de l’ischemie critique des membres inferieurs lorsque la disponibilite de la veine autologue est limitee et lorsqu’un segment arteriel isole popliteo-distal existe. Nous rapportons une technique modifiee de pontage sequentiel composite et le resultat de son utilisation sur une periode de 14 ans. Methodes Vingt-cinq procedures de pontages sequentiels composites modifies ont ete effectuees chez 24 patients pour traiter une gangrene, des ulceres ischemiques et des douleurs severes de repos. Des greffons veineux ont ete anastomoses entre un segment d’artere poplitee ou d’artere distale suspendu au-dessus du genou (7) ou sous le genou (18) et une artere distale de jambe incluant l’artere poplitee sous-articulaire (1), l’artere tibiale posterieure (5), l’artere tibiale anterieure (7) ou l’artere peroniere (12). Des pontages en Polytetrafluoroethylene ont ensuite ete intercales entre une artere donneuse satisfaisante et le segment proximal du greffon veineux. Resultats Les taux de permeabilite primaire cumules ont ete de 80% a trois ans et de 65% a 5 ans. Le taux de sauvetage de membre a ete de 85% a quatre ans. L’occlusion du segment prothetique avec un segment distal veineux restant permeable a ete authentifiee chez deux patients presentant une recidive moins severe d’ischemie. Le sauvetage de membre chez ces patients a ete obtenu en effectuant un nouveau pontage prothetique revascularisant le greffon veineux permeable. Conclusion Notre configuration modifiee d’anastomose entre la prothese et la veine pour la realisation d’un pontage sequentiel composite represente une alternative a la procedure conventionnelle et pourrait aider a preserver la permeabilite du greffon veineux en cas de thrombose de la prothese de polytetrafluoroethylene.

Background Composite sequential femoro-popliteal-distal bypass is a valuable option for treatment of critical limb ischemia when autogenous vein is limited and an isolated popliteal or distal arterial segment exists. We report a modified technique for composite sequential bypass and the results with its use over a 14-year period. Methods Twenty-five modified composite sequential bypass procedures were performed on 24 patients to treat gangrene, ischemic ulceration, and severe rest pain. Vein grafts were anastomosed from blind popliteal or blind distal arterial segments above-knee (7) or below-knee (18) to a distal outflow vessel including the below-knee popliteal (1), posterior tibial (5), anterior tibial (7), or peroneal (12) artery. Polytetrafluoroethylene bypass grafts were then placed from a suitable inflow artery to the proximal hood of the vein graft. Results Cumulative primary patency rates were 80% at 3 years, and 65% at 5 years. The limb-salvage rate was 85% at 4 years. Occlusion of the prosthetic segment with a patent distal vein segment was recognized in two patients who presented with less severe recurrent ischemia. Limb-salvage in these patients was achieved by a secondary prosthetic graft to the patent vein graft. Conclusion Our modified configuration of the prosthetic-vein anastomosis for composite sequential bypass is an alternative to the conventional procedure and may help preserve vein graft patency should the polytetrafluoroethylene graft thrombose.

Rationnelle Il a ete bien etabli que la mise en place d’un filtre de veine cave inferieure (VCI) au moment de la chirurgie ouverte de bypass gastrique (BGO) chez les patients ayant un indice de masse corporelle superieur a 55 kg/m2 reduit le taux d’embolie pulmonaire et la mortalite perioperatoire. Cependant, peu de choses sont connues au sujet des effets a long terme des filtres gastrique dans ce groupe particulier de patients. Methodes Sur une periode de huit ans, un total de 571 patients obeses morbides ont subi des procedures de BGO, et 58 (10%) d’entre eux ont necessite la mise en place d’un filtre VCI en preoperatoire. Chaque filtre VCI etait place par voie percutanee par une approche de veine femorale en utilisant un arceau mobile OEC. Les types de filtres VCI utilises dans notre etude etaient TrapEase (n = 35), Simon-Nitinol (n = 9), Greenfield (n = 2), et Bard Recovery (n = 12). Resultats Des 58 patients qui ont eu besoin d’un filtre VCI, 56 sont restes exempts de tout phenomene thromboembolique au cours de la periode de huit ans (extremes, 1-8 ans). Les deux autres patients ont developpe une thrombose veineuse profonde. Une patiente a ete traitee avec succes avec de l’heparine intraveineuse et six mois de Coumadine. Elle a eu la resolution complete de sa thrombose veineuse profonde et il a ete fortuitement trouve une mutation genique de la prothrombine 20210. L’autre patiente, qui a eu des complications multiples de la deviation gastrique, ne pouvait pas etre traitee efficacement avec de l’heparine intraveineuse et progressa jusqu’a la thrombose de la VCI. Elle a developpe une phlegmasia cerulea dolens et fut amputee des deux cotes au-dessus du genou. Elle est morte 3 mois apres ses procedures. Conclusion Il s’avere que la mise en place d’un filtre VCI lors d’un BGO est une intervention relativement benigne avec un avantage maximal. Il faudrait porter attention aux patients obeses qui ont une hypercoagulabilite et a ceux qui ont des complications liees a la deviation gastrique. Une attitude agressive, qui peut se composer d’une anticoagulation immediate apres les procedures (seulement si elle est consideree sure), devrait etre preconisee dans ce petit sous-groupe de patients obeses morbides.

L'obesite augmente de maniere independante le risque d'embolie pulmonaire (EP). Nous comparons une population de grands obeses (index de masse corporelle [BMI] > 55 kg/m2) subissant des courts-circuits gastriques a ciel ouvertes (OGB) a un groupe apparie de courts-circuits gastriques laparoscopiques (LGB) pour voir si l'incidence de l'EP est differente. Nous avons inclus tous les patients subissant un OGB ( n = 193, BMI moyen = 51 kg/m2) dans notre etablissement par un seul chirurgien entre juillet 1999 et avril 2001. Trente et un patients etaient de grands obeses (BMI > 55 kg/m2). Les LGB ont ete introduits dans notre etablissement en avril 2001. Depuis lors 213 patients (BMI moyen = 52 kg/m2) ont subi cette intervention. Cent neuf de ces patients etaient de grands obeses. La prophylaxie pre- et postoperatoire incluait des bas de compression graduee et de l'heparine sous-cutanee. En postoperatoire, les patients qui ont developpe des signes d'hypoxie, une tachypnee, ou une tachycardie ont eu une radiographie thoracique et un scanner helicoidal. En outre, tous les patients decedes au cours des 30 jours postoperatoires ont ete autopsies. Les donnees ont ete analysees a l'aide du test du Chi 2 . Dans le groupe OGB, quatre patients (2,1%) ont developpe une EP. Toutes les EP se sont produites chez les grands obeses avec BMI > 55 kg/m2. Trois furent fatales et une non fatale. Aucun de ces patients n'avait des antecedents de thrombose veineuse profonde (DVT), d'EP, d'insuffisance veineuse, ou d'hypertension pulmonaire. Dans le groupe LGB, un patient (0,9%) a eu une EP non fatale. Ce patient avait un antecedent de thrombose veineuse profonde. L'incidence de l'EP etait statistiquement plus elevee dans le groupe des grands obeses traites par OGB ( p 55 kg/m2 pourraient avoir un risque accru d'EP independamment de la voie d'abord.

Objective Patients undergoing open gastric bypass (OGB) for morbid obesity are at significant risk for pulmonary embolism (PE) despite the use of subcutaneous heparin injections and sequential compression devices. Prophylactic preoperative inferior vena cava (IVC) filter placement may reduce this risk. We report our experience with simultaneous IVC filter placement and OGB in an operating room setting. Methods From July 1999 to April 2001, 193 patients (group 1) underwent OGB. Eight patients had prophylactic intraoperative IVC filters placed for deep vein thrombosis, PE, or pulmonary hypertension. From May 2001 to January 2003, 181 patients (group 2) underwent OGB. There were 33 IVC filters placed for body mass index (BMI) greater than 55 kg/m 2 in addition to the above-mentioned criteria. To confirm observations made in group 1 and 2 patients, from July 2003 to May 2005, 197 patients (group 3) underwent OGB, and patients with a BMI greater than 55 kg/m 2 (n = 35) were offered IVC filter placement. Group 3A (n = 17) consented to IVC filter placement, and group 3B (n = 18) did not. Results Fifty-eight IVC filters were placed (100% technical success rate) with an increase in operating room time of 20 ± 5 minutes. In group 1, the eight patients with IVC filters had a BMI greater than 55 kg/m 2 . There were four PEs (3 fatal and 1 nonfatal) in the other 185 patients, all which occurred in patients with BMIs greater than 55 kg/m 2 . In group 2, there were no PEs. The perioperative PE rate in these patients was reduced from 13% (4/31; 95% confidence interval [CI], 1.1%-25.7%) to 0% (0/33; 95% CI, 0%-8.7%). Perioperative mortality was reduced from 10% (3/31; 95% CI, 0%-20.0%) to 0% (0/33; 95% CI, 0%-8.7%). There were no pulmonary emboli or deaths related to PE in group 3A patients. Group 3B patients had a 28% PE rate (two fatal and three nonfatal) and an 11% PE-related death rate. None of the remaining patients in group 3 had a PE. Conclusions Intraoperative IVC filter placement for the prevention of PE in morbidly obese patients undergoing OGB is feasible. We observed a significant reduction in the perioperative PE rate when a BMI greater than 55 kg/m 2 was used as an indication for IVC filter placement despite the use of subcutaneous heparin injections and sequential compression devices.

Objective Proximal neck dilatation (PND) and/or endograft migration with the subsequent development of type I endoleak is a significant cause of late endograft failure after endovascular abdominal aortic aneurysm repair (EVAR). Although there are numerous reports examining PND in patients receiving endografts that use self-expanding stents (SES) for proximal fixation, there are no such reports for patients treated with endografts that use balloon-expanding stents (BES). The purpose of this study was to investigate PND and endograft migration after EVAR with BES endografts. Methods We retrospectively reviewed all charts and all serial computed tomographic scans available for patients who underwent EVAR with a BES endograft (surgeon-made, aortounifemoral polytetrafluoroethylene graft with a proximal Palmaz stent) between August 1997 and October 2002. Only patients with longer than a 12-month follow-up were analyzed. Neck diameter was measured at the level of the lowest renal artery and at 5 mm below it. PND was defined as neck enlargement of 2.5 mm or more. To assess endograft migration, the distance between the superior mesenteric artery and the cranial end of the BES was measured. Stent migration was defined as a change of 5 mm or more. Results A total of 77 patients received this device during the study period. The technical success rate was 99%. The 1-, 3-, and 5-year survival was 66%, 48%, and 29.5%, respectively. Complete serial computed tomographic scans were available in 41 of the 48 patients who survived 12 months or longer after the operation. The mean follow-up period for these patients was 31 months (range, 12-66 months). The maximum aneurysm diameter was either unchanged or decreased in 35 patients (85%). The immediate postoperative proximal neck diameter was 19 to 29 mm (median, 24 mm). This was unchanged at the latest follow-up. None of the patients had significant PND. The cranial end of the BES was located in the area between 14 mm proximal and 36 mm distal to the superior mesenteric artery (median, 6 mm). None of the patients developed significant endograft migration. Conclusions Neither PND nor endograft migration was observed with the BES endograft. The nature of the SES may be responsible for the observed neck dilatation and device migration after EVAR with SES endografts. This study suggests that BES may be a better fixation method for EVAR.

Objective(s)We have previously shown that type II endoleak size is a predictor of aneurysm growth after aortic endografting. To better understand this observation, we investigated the influence of endoleak size on pressure transmitted to the aneurysm wall and its distribution within the aneurysm sac.MethodsIn an ex vivo model, an artificial aneurysm sac was incorporated within a mock circulation comprised of rubber tubing and a pulsatile pump. Three strain-gauge pressure transducers were placed in the aneurysm wall at different locations, including the site of maximum aneurysm diameter. The aneurysm was filled with either human aneurysm thrombus or dough that mimicked thrombus and simulated type II endoleaks of varying volumes (1 to 10 mL) were created. Aneurysm wall pressure (AWP) measurements were recorded at mean arterial pressures (MAPs) of 60, 80, and 100 mm Hg. Correlation coefficients (r) and analysis of variance were used to assess the relationship between endoleak volume and AWP.ResultsIncreasing endoleak volume ’3 cm3 resulted in proportionally increased AWP at all levels of MAP and at all sites, with highest pressures recorded at the site of the maximum aneurysm diameter (r = 0.83 when MAP = 100 mm Hg; r = 0.85 when MAP = 80 mm Hg; r = 0.88 when MAP = 60 mm Hg; P < .001). AWP plateaued when the endoleak volume was >3 cm3. Pressure distribution within the sac was not uniform. Although the difference was within ±10%, statistically significant higher AWPs were observed at the site of maximum aneurysm diameter (P

Background To evaluate whether abdominal aortic aneurysm (AAA) growth in individual patients can be characterized as continuous or discontinuous (staccato). Study design From 1996 to 2002, 609 patients presented with unruptured AAAs. Of these, 278 underwent prompt repair and 331 were observed. In this study, we included 52 patients (16% of the latter group) who had at least four CT scans and were observed for 18 months or longer without any intervention. AAA growth was defined as any increase in diameter of ≥ 3 mm over any observation period(s). AAA nongrowth was defined as absence of growth for at least 6 months. Staccato growth was defined as at least one period of nongrowth combined with at least one period of growth. Results The 52 patients had a mean age of 75 ± 8 (SD) years. The mean observation period was 42 ± 20 months and the mean AAA diameter growth rate was 3.6 ± 2.4 mm/y. Only 12 of these 52 patients (23%) demonstrated continuous growth. Staccato growth occurred in 34 patients (65%). Six patients (12%) showed no growth at all over 18 to 57 months (mean 30 months). No correlation was observed between initial diameter of AAAs and a patient's individual growth rate during the whole observation period ( R = 0.04, p = 0.46). Conclusions Individual AAA behavior is usually characterized by periods of nongrowth alternating with periods of growth, ie, staccato growth. Some aneurysms may have long periods of nongrowth. Accordingly, management decisions cannot be based on the presumption that observed growth rates of AAAs can be extrapolated to predict future growth rates.

The clinical significance of type II endoleaks is not well understood. Some evidence, however, indicates that some type II endoleaks might result in aneurysm enlargement and rupture. To identify factors that might contribute to aneurysm expansion, we analyzed the influence of several variables on aneurysm growth in patients with persistent type II endoleaks after endovascular aortic aneurysm repair (EVAR).In a series of 348 EVARs performed during a 10-year period, 32 patients (9.2%) developed type II endoleaks that persisted for more than 6 months. Variables analyzed included those defined by the reporting standards for EVAR (SVS/AAVS) as well as other endoleak characteristics. Univariate, receiver operating characteristic curve, and Cox regression analyses were used to determine the association between variables and aneurysm enlargement.The median follow-up period was 26.5 months (range, 6-88 months). Thirteen patients (41%) had aneurysm enlargement by 5 mm or more (median increase in diameter, 10 mm), whereas 19 (59%) had stable or shrinking aneurysm diameter. Univariate and Cox regression analyses identified the maximum diameter of the endoleak cavity, ie, the size of the nidus as defined on contrast computed tomography scan, as a significant predictor for aneurysm enlargement (relative risk, 1.12; 95% confidence interval, 1.04-1.19; P =.001). The median size of the nidus was 23 mm (range, 13-40 mm) in patients with aneurysm enlargement and 8 mm (range, 5-25 mm) in those without expansion (Mann-Whitney U test, P.001). Moreover, receiver operating characteristic curve and Cox regression analyses showed that a maximum nidus diameter greater than 15 mm was particularly associated with an increased risk of aneurysm enlargement (relative risk, 11.1; 95% confidence interval, 1.4-85.8; P =.02). Other risk factors including gender, smoking history, hypertension, need of anticoagulation, aneurysm diameter, type of endograft used, and number or type of collateral vessels were not significant predictors of aneurysm enlargement.In patients with persistent type II endoleaks after EVAR, the maximum diameter of the endoleak cavity or nidus is an important predictor of aneurysm growth and might indicate the need for more aggressive surveillance as well as earlier treatment.

ObjectivesWe noted substantial differences when measuring repeatedly the same abdominal aortic aneurysm (AAA) on the same computed tomography (CT) scan. This study quantitated this variability, and methods to minimize it were developed.MethodsThe CT maximal diameter of 25 AAAs was measured by eight experienced observers, including six vascular surgeons and two radiologists, using two methods: an unstandardized protocol, and a standardized protocol using fine calipers to carefully measure the largest diameter perpendicular to the estimated aneurysm centerline, from outer aneurysm wall to outer wall. The average measurement difference between observers was calculated for each method. The average difference between each observer's measurement and the official radiology report value was also calculated. Agreement between the two measurement methods was assessed with Bland-Altman plots.ResultsThe difference in maximal diameter measurements between each observer averaged 4.0 ± 5.1 mm (range, 0.0-35.0 mm) with the unstandardized method. The mean measurement difference with the standardized protocol was significantly lower, and averaged 2.8 ± 4.4 mm (range, 0.0-26.0 mm; P < .05). Measurements taken from the official radiology report differed from each of the observer's standardized measurement by an average of 5.0 ± 6.3 mm (range, 0.0-28.0 mm). This difference was similar for both the unstandardized and standardized methods. Bland-Altman plots confirmed the wide variation of the maximal diameter measurements when the unstandardized method was compared with the standardized method (95% confidence interval, −9-9 mm).ConclusionsRoutine CT maximal diameter measurement of AAAs can have substantial interobserver variability. Standardized measurement protocols can decrease, but not eliminate, this measurement variability. Thus apparent size changes based on CT measurements may represent measurement artifact rather than actual aneurysm growth or shrinkage, particularly when a standardized system is not used.

The recent explosion of interest in morbid obesity surgery and its associated complications (deep venous thrombosis and pulmonary embolism) has inadvertently captured the attention of many vascular specialists. This article will focus on the indications and techniques used at Jack D. Weiler Hospital of the Albert Einstein College of Medicine for inferior vena cava filter placement prior to open and laparoscopic bariatric surgical procedures.

ObjectivesReduction of length of stay (LOS) is critical for optimal use of hospital resources. We developed and evaluated a system to aggressively reduce LOS for vascular surgery.MethodKey to this system, which we introduced on January 1, 2001, was appointment of a LOS officer, who communicated daily during hospitalization with patients and families about discharge planning, organized outpatient services for wound care and rehabilitation to transition patients quickly to nonhospital care, and had biweekly meetings with relevant paramedical services. LOS for 509 patients operated on in 2000 (standard group) was compared with LOS for 474 operated on in 2001 and 595 patients operated on in 2002 (LOS reduction groups). Data for all patients with aortic aneurysm, carotid artery stenosis, lower extremity critical ischemia or amputation, and foot debridement were included.ResultsLOS in 2000 averaged 8.5 days, compared with 5.9 days in 2001 and 5.6 days in 2002. All decreases in LOS for each diagnostic category in 2001 and 2002 were statistically significant (P = < .001-.03). There was no significant increase in readmission rate (2.2% vs 1.9% and 2.0%, respectively), mortality rate (0.8% vs 0.6% and 0.7%, respectively), or percent of patients who received endovascular treatment (18% vs 16% and 14%, respectively). These decreases in LOS saved the hospital more than $616,200 in 2001, and $847,550 in 2002 ($500/patient-day).ConclusionsA committed LOS officer with major specific daily responsibilities for decreasing LOS and discharging patients resulted in a 31% to 33% decrease in LOS, with important cost savings to the hospital and no negative effect on patient care.

Purpose: To evaluate the patency rates of femorofemoral grafts performed in conjunction with aortomonoiliac or aortomonofemoral (AMI/F) endografts. Methods: Over the past 8 years, 110 patients (98 men; mean age 77 ± 7 years, range 57–90) underwent aortoiliac aneurysm repair with an AMI/F endograft. Follow-up data in these patients were prospectively collected for a mean 2.3 years (range 1–68 months). Results: There were 2 early (Conclusions: Femorofemoral bypasses with AMI/F endografts for aneurysmal disease are durable procedures and have better patency than femorofemoral grafts used to treat occlusive disease. Femorofemoral bypass patency rates alone are not a disadvantage of aortomonoiliac endografts.

ObjectivesTransrenal fixation (TFX) of aortic endografts is thought to increase the risk for renal infarction and impaired renal function. We studied the late effects of TFX on renal function and perfusion.MethodsOf 189 patients with commercial aortic endografts, which we inserted between 1995 and 2002, we reviewed data for 130 patients (112 men, 18 women) with available creatinine (Cr) concentration and contrast enhanced computed tomography (CT) scans preoperatively and 1 to 97 months after the procedure. Of the 130 patients, 69 patients had TFX and 61 patients had infrarenal fixation (IFX). Both groups were physiologically comparable. Average age was 76 ± 8 years for patients with TFX and 75 ± 8 years for patients with IFX. Presence of renal infarct or renal artery occlusion was determined by nephrograms on serial contrast-enhanced CT scans.ResultsMean follow-up was 17 ± 16 months (range, 1-54 months) for TFX and 21 ± 21 months (range, 1-97 months) for IFX. Mean serum Cr concentration increased significantly during long-term follow-up in both groups (TFX, 1.3 ± 0.5 mg/dL to 1.5 ± 0.8 mg/dL, P < .01; IFX, 1.3 ± 0.7 mg/dL to 1.4 ± 0.8 mg/dL, P < .03). Creatinine clearance (CrCl) similarly decreased over long-term follow-up in both groups (TFX, 53.3 ± 17.7 mL/min/1.73 m2 to 47.9 ± 16.2 mL/min/1.73 m2, P < .01; IFX, 58.1 ± 22.7 mL/min/1.73 m2 to 53.1 ± 23.4 mL/min/1.73 m2, P < .02). There were no significant differences in the increase in Cr concentration (P = .19) or decrease in CrCl (P = .68) between TFX and IFX groups. Small renal infarcts were noted in four patients (5.8%) in the TFX group and one patient (1.6%) in the IFX group. No increase in Cr concentration or decrease in CrCl was noted in any patient with a renal infarct. Postoperative renal dysfunction developed in 7 of 69 patients (10.1%) in the TFX group and 7 of 61 patients (11.5%) in the IFX group. There were no statistically significant differences between groups with respect to number of patients with new renal infarcts (P = .37) or postoperative renal dysfunction (P = .81).ConclusionThere is a slight increase in serum Cr concentration and decrease in CrCl after aortic endografting. However, there was no significant difference in these changes between patients with TFX and IFX. Although TFX may produce a higher incidence of small renal infarcts, these do not impair renal function. Thus our midterm results suggest that TFX can be performed safely, with no greater change in renal function than observed after IFX.

Ruptured abdominal aortoiliac aneurysms, when treated with open surgical repair, have high morbidity and mortality rates. Since 1994, the authors have used endovascular approaches to treat this entity. Patients with presumed ruptured aortoiliac aneurysms were treated with restricted fluid resuscitation (hypotensive hemostasis), transport to the operating room, placement under local anesthesia of a brachial or femoral guide wire into the supraceliac aorta, and arteriography. If aortoiliac anatomy was suitable, an endovascular graft (stent-graft) repair was performed. If the anatomy was unfavorable, standard open repair was performed. Only if circulatory collapse occurred was a supraceliac balloon placed and inflated using the previously positioned guidewire. Of 35 patients treated in this manner, 29 underwent endovascular graft repair, and 6 required open repair. Four patients died within 30 days (operative mortality rate, 11%). Only 10 patients required supraceliac balloon control. Endovascular grafts, when combined with hypotensive hemostasis and other endovascular techniques including proximal balloon control, may improve treatment outcomes with ruptured abdominal aortoiliac aneurysms. The authors believe these techniques will become widely used for the treatment of ruptured aneurysms.

Objective: Patients with infrainguinal occlusive disease may experience spontaneous symptomatic improvement. This is generally thought to be from augmented collateral circulation. This study reports another mechanism. Methods: Over a 20-year period, 4123 paients underwent lower extremity arteriography for limb ischemia. For a variety of reasons, 451 patients had repeat arteriography. Results: Five patients were identified as having conclusive arteriographic evidence of spontaneous recanalization of occluded arterial segments without having undergone any surgical or thrombolytic interventions. Repeat contrast arteriography was performed on these patients for failing grafts (n = 2) or contralateral lower extremity ischemia (n = 3). Three other patients had magnetic resonance arteriographic or duplex arteriographic evidence of spontaneous arterial recanalization. Spontaneous recanalizaton occurred in ileofemoral (n = 2), superficial femoral (n = 2), popliteal (n = 3), and peroneal (n = 1) arterial segments. The average time interval of occlusion to recanalization was 21 weeks (2 weeks to 2 years). Two of the eight patients had failed revascularization procedures before spontaneous recanalization. All eight patients had restoration of pulses distal to the recanalized segments and significant symptomatic improvement as defined with the Society for Vascular Surgery/American Association for Vascular Surgery categories for limb ischemia. Conclusion: Spontaneous recanalization of arterial segments can occur and must be considered when evaluating other proposed treatments of critical limb ischemia, including cilostazol, lytic agents, and angiogenic agents, such as vascular endothelial growth factor. Although its true incidence is unknown, this represents another mechanism for spontaneous symptomatic improvement without treatment in patients with severe limb ischemia. (J Vasc Surg 2002;36:1161-6.)

Objective: Carotid artery stenting (CAS) for treatment of carotid stenosis has not received wide acceptance because of the availability of carotid endarterectomy (CEA) with its excellent results and because of the risk of embolic stroke associated with CAS. The feasibility and efficacy of cerebral protection devices that may prevent such embolic complications have yet to be shown. We report our initial results with CAS performed with cerebral protection. Methods: For a period of 28 months, 31 patients with carotid artery stenosis, most of whom were considered at high risk for CEA (87%), underwent treatment with CAS in conjunction with either the PercuSurge GuardWire (n = 19; Medtronic, Minneapolis, Minn), the Cordis Angioguard filter (n = 7; Cordis, Warren, NJ), or the ArteriA Parodi Anti-embolization catheter (n = 4; ArteriA, San Francisco, Calif) with US Food and Drug Administration-approved investigational device exemptions. Factors that made CEA high risk included restenosis after CEA (n = 6), hostile neck (n = 6), high or low lesions (n = 4), and severe comorbid medical conditions (n = 11). Preoperative neurologic symptoms were present in 58%, and the mean stenosis was 85% ± 12%. Data were prospectively recorded and analyzed on an intent-to-treat basis. Neurologic evaluation was performed before and after CAS by a protocol neurologist. Results: CAS was performed with local anesthesia with the Wallstent (n = 23; Boston Scientific Corp, Natick, Mass) or the PRECISE carotid stent (n = 7; Cordis) in conjunction with one of the protection devices in an operating room with a mobile C-arm. Each patient received dual antiplatelet therapy before surgery. The overall technical success rate was 97% (30/31). In one patient, the lesion could not be crossed with a guidewire because of a severely stenosed and tortuous lesion. This patient was not a candidate for CEA and was treated conservatively. In the remaining 30 cases, CAS had a good angiographic result (residual stenosis

Objective: An accepted fact is that abdominal aortic aneurysms (AAAs) larger than 5.5 cm should undergo elective repair. However, subsets of these patients have serious comorbid conditions, which greatly increase operative risk. This study evaluated the outcomes of periods of protracted nonoperative observational management with selective delayed surgery in patients at high risk with large infrarenal and pararenal AAAs. Methods: Among 226 patients with AAAs more than 5.5 cm, we selected 72 with AAAs from 5.6 to 12.0 cm (mean, 7.0 cm) for periods of nonoperative management because of their prohibitive surgical risks. Comorbid factors included a low ejection fraction of 15% to 34% (mean, 22%) in 18 patients, 1 second forced expiratory volume less than 50% (mean, 38%) in 25, prior laparotomy in 10, and morbid obesity in 22. Follow-up examination was complete in the 72 patients for the 6 to 76 months (mean, 23 months) that they underwent nonoperative treatment. Fifty-three patients ultimately underwent operation because of AAA enlargement or onset of symptoms after 6 to 72 months (mean, 19 months) of nonoperative treatment. Results: Of the 72 selected patients, 54 (75%) are living and 18 (25%) are dead. Seven patients who underwent only nonoperative treatment presently survive after 28 to 76 months (mean, 48 months). Of the 18 deaths, AAA rupture occurred in only three patients (4%) who were observed for 12, 31, and 72 months before rupture. Nine other deaths (13%) occurred after 6 to 72 months from comorbidities unrelated to the AAA. Six of the 53 patients who underwent delayed operation died within 30 days of operation (11% mortality rate). The mortality rate for the 154 good-risk patients with an AAA who underwent prompt open or endovascular repair was 2.2%. Conclusion: These data indicate that some patients with large AAAs and serious comorbidities are acceptably managed for long periods (6 to 76 months) with nonoperative means. Substantial delays of 12 to 76 months resulted in an AAA rupture rate of only 4%, and 13% of these patients (nine of 72) died of comorbidities unrelated to AAA rupture or surgery. Mortality rate in this group of patients, when operated, was 11% (six of 53). These findings support the selective use of nonoperative management in some patients with large AAAs and serious comorbidities. (J Vasc Surg 2002;36:41-6.)

Objective: The purpose of this study was to analyze the incidence, severity, and etiologic factors of the development of colon ischemia after endovascular aortoiliac aneurysm repair (EVAR). Methods: During the last 9 years we performed 278 elective EVARs using a variety of grafts. To facilitate these repairs, one hypogastric artery (HA) was coil embolized in 109 patients and both HAs were coil embolized in 13 patients. The preprocedural status of the inferior mesenteric, hypogastric, and iliac arteries as well as anatomical characteristics of the abdominal aortic aneurysm were determined arteriographically and by computerized tomographic scans. Postoperative colon ischemia was documented by colonoscopy or operative findings. Results: Colon ischemia occurred in eight patients (2.9%). Three patients with colon ischemia died and had evidence of widespread (cutaneous, renal, small bowel, and/or lower extremity) microembolization. One of these three had a colectomy and microscopic emboli were present. One other patient who required a colectomy also had pathologic evidence of colonic microembolization but survived. Four other patients with colon ischemia were treated conservatively and survived. In one patient, previous colectomy with interruption of mesenteric collaterals may have been a contributory cause of colon ischemia. Of the eight patients with colon ischemia, only one had unilateral HA occlusion, and none had bilateral HA occlusion. The other 121 patients with unilateral and bilateral HA occlusion had no evidence of colon ischemia. Conclusions: Colon ischemia occurs after EVAR with an incidence approximating that of open repair. Colon ischemia was unrelated to HA interruption. Embolization appears to be a major cause of colon ischemia, although inadequate mesenteric collateral circulation may also play an etiologic role. Mortality with colon ischemia accompanied by widespread embolization was high, whereas colon ischemia without it was often mild and amenable to nonoperative management. (J Vasc Surg 2001;34:986-96.)

Objective: Lower extremity arterial reconstructions with in situ greater saphenous vein (GSV) are an important component of limb salvage surgery. Initially, the procedure was performed through continuous skin incisions for side branch occlusion and valve lysis with a wound complication rate of 5% to 25%. To decrease these complications, we used endoscopic GSV harvest equipment in 25 in situ vein bypass grafts in 25 patients performed over 24 months. Methods: The procedures were performed with three skin incisions: two for arterial access and a 2-cm incision above the knee to insert the Endopath device (Ethicon) to locate and clip the GSV side branches. After completion of the proximal anastomosis, the valves were lysed through the distal end of the vein with a flexible valvulotome. Completion cineangiography was performed to confirm side branch occlusion and evaluate the entire reconstruction. The results of this technique were compared with our last 25 in situ bypass grafts done with standard long incisions. Results: In the endoscopic group there was one (4%) minor wound complication (cellulitis). No postoperative arteriovenous fistulas were detected by means of duplex examination, and the average hospital stay was 6.2 ± 1 days. One graft closed at 9 months as a result of distal vein hyperplasia, but the other grafts have remained patent, with follow-up from 6 to 30 months (mean, 18 months). Patients with the standard in situ bypass grafts had significantly (P

Purpose: This report describes our 5-year experience with the endovascular repair of isolated iliac aneurysms and pseudoaneurysms. Methods: Between June 1993 and July 1998, 40 isolated iliac aneurysms and pseudoaneurysms were treated with endovascular grafts in 39 patients. Thirty-seven aneurysms were treated with endovascular grafts composed of polytetrafluoroethylene grafts and balloon expandable stents, and the other three underwent repair with a polycarbonate urethane endoluminal graft. Results: All the patients underwent initially successful endovascular treatment of isolated iliac aneurysms and pseudoaneurysms and were followed from 1 to 51 months (mean, 18 months). The 4-year primary patency rate was 94.5% ± 10%. The perioperative complications included one episode of distal embolization, an episode of colonic ischemia, five episodes of kinking or compression of the endovascular graft, and one early postoperative graft thrombosis. There was only one perioperative death in a patient whose aneurysm ruptured in the operating room just before endovascular repair. The median postoperative length of hospital stay was 3.0 ± 1.3 days in this group of patients at moderate and high risk. The long-term complications included one graft thrombosis and two endoleaks. One small endoleak was followed until the patient died of unrelated causes, and the other one led to aneurysm rupture in the only patient temporarily lost to follow-up examination. This patient successfully underwent treatment in the standard open surgical fashion. To date, all the other aneurysms have remained stable or have decreased in size during the follow-up examinations with duplex or contrast-enhanced computed tomographic scans. Conclusion: Endovascular repair of iliac aneurysms and pseudoaneurysms is a safe and effective technique with good midterm results in patients at standard and high risk. These grafts are particularly beneficial for patients with medical, surgical, or anatomic contraindications for open surgical repair. (J Vasc Surg 1999;30:907-14.)

Background: C-fos and c-jun are 2 immediate early genes that have been implicated in the stimulation of vascular smooth muscle cell proliferation and migration. In previous experiments in our laboratory with a rat vein graft model a 2- to 3-fold increase of messenger RNA of c-fos and c-jun were noted 1 hour after vein graft perfusion. Because c-fos and c-jun are up-regulated after the perfusion of vein grafts, the purpose of this study was to delineate the temporal expression of c-fos and c-jun protein and to study the effect of antisense oligonucleotides (ASO) to c-fos and c-jun on intimal thickening observed in this model. Methods: Sprague-Dawley rats underwent bilateral interposition femoral artery grafts with use of the superficial epigastric vein, which was harvested from 15 minutes up to 2 weeks and analyzed by Western blot for Fos and Jun protein. Additional rats underwent bypasses and at the time of the procedure 1 graft was treated with a pluronic gel containing an ASO to c-fos, c-jun, or sense and the contralateral side was treated with pluronic gel only. The vein grafts were harvested 2 weeks after the procedure and perfusion fixed. After longitudinal sectioning, the intimal and total wall thicknesses were measured in the perianastamotic and midgraft regions by a morphometric digitizing microscope and the statistics were analyzed by a paired Student's t test. Results: Protein analysis by Western blot showed that c-fos levels rose quickly within 2 hours and leveled at 6 hours 40-fold above basal levels after vein graft perfusion. Similarly, c-jun levels rose 10-fold above basal levels after 15 minutes and peaked at 2 hours 120-fold above basal levels. The treatment of the vein grafts with these ASOs resulted in a reduction of about 30% in the thickness of the intimal layer and the total wall thickness in both the perianastomotic and the midgraft regions, which was statistically significant different from control veins. Conclusion: These results indicate a possible therapeutic role for ASO to immediate early genes in the treatment of vein graft intimal hyperplasia. (Surgery 1999;126:443-9.)

Background: The feasibility of endovascular graft (EVG) repair of ruptured aortoiliac aneurysms (AIAs) has yet to be demonstrated. There are inherent limitations in EVG repair, including the need for preoperative measurements of the aneurysmal and adjacent arterial anatomy to determine the appropriate size and type of graft and the inherent delay to obtain proximal occlusion. We developed an EVG system with broad versatility that largely eliminates these problems. Study Design: Between 1993 and 1998, within an experience of 134 endovascular AIA repairs, 12 ruptured AIAs were treated using EVGs that facilitated intraoperative customization and eliminated the need for preoperative measurements. The EVGs consisted of either a Palmaz stent and a PTFE graft deployed by a compliant balloon (n = 9) or a self-expanding covered stent graft (n = 3). Both grafts were cut to the appropriate length intraoperatively. The mean age of the patients was 72 years (range 40 to 86 years). The mean size of the aneurysms was 7.6 cm (range 3 to 16 cm). Preoperative symptoms were present in all patients and included abdominal or back pain (n = 9), syncope (n = 4), and external bleeding (n = 2). All patients were high surgical risks because of comorbid disease (n = 10) or previous abdominal operations (n = 6), and nine experienced hypotension. Results: All EVGs were inserted successfully and excluded the aneurysms from the circulation. The mean operating time was 263 minutes, the mean blood loss was 715 mL, and the mean length of hospital stay was 6.5 days. There were two deaths (16%), one from the preexisting acute myocardial infarction and one from multiple organ failure. There were three minor complications (25%). Two patients required evacuation of an intraabdominal hematoma from the initial rupture. All but one of the grafts was functioning at a mean followup of 18 months. Conclusions: This study demonstrates the feasibility of EVG repair for ruptured AIAs using a graft that can be customized intraoperatively for each patient. Such repairs currently are valuable in patients with ruptured AIAs and serious comorbidities and may be applicable in other circumstances as well.

Purpose: Arteriography is the diagnostic test of choice before lower extremity revascularization, because it is a means of pinpointing stenotic or occluded arteries and defining optimal sites for the origin and termination of bypass grafts. We evaluated whether a duplex ultrasound scan, used as an alternative to arteriography, could be used as a means of accurately predicting the proximal and distal anastomotic sites in patients requiring peripheral bypass grafts and, therefore, replace standard preoperative arteriography. Methods: Forty-one patients who required infrainguinal bypass grafts underwent preoperative duplex arterial mapping (DAM). Based on these studies, an observer blinded to the operation performed predicted what operation the patient required and the best site for the proximal and distal anastomoses. These predictions were compared with the actual anastomotic sites chosen by the surgeon. Results: Whether a femoropopliteal or an infrapopliteal bypass graft was required was predicted correctly by means of DAM in 37 patients (90%). In addition, both anastomotic sites in 18 of 20 patients (90%) who had femoropopliteal bypass grafts and 5 of 21 patients (24%) who had infrapopliteal procedures were correctly predicted by means of DAM. Conclusion: DAM is a reliable means of predicting whether patients will require femoropopliteal or infrapopliteal bypass grafts, and, when a patient requires a femoropopliteal bypass graft, the actual location of both anastomoses can also be accurately predicted. Therefore, DAM appears able to replace conventional preoperative arteriography in most patients found to require femoropopliteal reconstruction. Patients who are predicted by means of DAM to require crural or pedal bypass grafts should still undergo preoperative contrast studies to confirm these results and to more precisely locate the anastomotic sites. (J Vasc Surg 1999;29:100-9.)

Purpose: Results of percutaneous transluminal angioplasty (PTA) in selected cases have been reported to be equal or superior to those of arterial bypass graft surgery, with a lower morbidity and mortality. We performed PTA of stenotic or occlusive lesions in patients with limb-threatening ischemia, hoping to improve our overall success and decrease morbidity in this group of patients. The results of PTA in the limb-salvage setting was evaluated. Methods: From 1992 to 1995, 307 PTAs were performed in 257 patients. One hundred sixty-one (63%) patients had diabetes mellitus, and 32 (12%) patients had renal failure. All patients were evaluated by means of pulse volume recordings and ankle brachial indices at 1 and 6 weeks after PTA and at 3 month intervals thereafter. Seventeen patients (9%) were lost to follow-up. The continued success or failure of PTA was defined by means of noninvasive vascular laboratory criteria, patency by means of pulse examination, the need for subsequent bypass grafting across the index lesion, and limb salvage. Results: The 1-year patency rates for external iliac PTAs (56%) were significantly lower (P < .05) than those for common iliac PTAs (87%). Infrainguinal PTAs at the femoral, popliteal, and tibial level had 1-year patency rates of less than 15%. Conclusion: Common iliac artery PTA is justified in most cases in which it is feasible. However, when PTAs are performed below the inguinal ligament, the results are markedly worse. One-year patency rates of PTA in this group of patients with threatened limbs are inferior to the patency rates of arterial bypass grafts, even when these bypasses are performed with a prosthetic material. PTA should not be considered as a primary treatment modality for patients with infrainguinal arterial occlusive disease who also have limb-threatening ischemia, except in unusual circumstances. (J Vasc Surg 1998;28:1066-71.)

Purpose: Anatomic features, such as a high carotid bifurcation (2.0 cm above the carotid bifurcation), or a small diameter (≤0.5 cm) redundant or kinked internal carotid artery can complicate carotid endarterectomy. In the past, arteriography was the only preoperative study capable of imaging these features. This study assessed the ability of duplex ultrasound to evaluate their presence before surgery. Methods: A consecutive series of 20 patients who underwent 21 carotid endarterectomies had preoperative duplex ultrasound evaluations of these anatomic features. These evaluations were correlated with operative measurements from an observer blinded to the duplex findings. Results: The mean difference between duplex and operative measurements for the distance between the carotid bifurcation and the angle of the mandible, the distal extent of plaque, and the internal carotid artery diameter was 0.9 cm, 0.3 cm, and 0.8 mm, respectively. The correlation coefficient between the two methods was 0.86, 0.75, and 0.59, respectively. Duplex ultrasound predicted a high carotid bifurcation, excessive distal extent of plaque, or a redundant or kinked internal carotid artery with 100% sensitivity (p < 0.05, p < 0.01, and p < 0.001, respectively). The sensitivity of duplex ultrasound in predicting a small internal carotid artery diameter was 80%. The specificity of duplex ultrasound for predicting excessive distal extent of plaque, small internal carotid artery diameter, high carotid bifurcation, and a coiled or kinked carotid artery was 92%, 56%, 100%, and 100%, respectively. Conclusions: Duplex ultrasound can predict the presence of anatomic features that may complicate carotid endarterectomy. Preoperative duplex imaging of these features may be helpful in patients who undergo carotid endarterectomy without preoperative arteriography. (J Vasc Surg 1998;27:235-44.)

Purpose: There are excellent arguments in favor of the preferential use of prosthetic grafts above the knee for the treatment of infrainguinal occlusive disease. This approach has been popularized on the basis of the seemingly acceptable results when using polytetrafluoroethylene (PTFE). However, in many centers, knitted Dacron polyester has been used in these patients, and there are several studies that show equivalent and, in some, superior results with Dacron when compared with PTFE. The purpose of this study was to examine these results in a definitive way. Methods: A randomized prospective trial in eight clinical academic centers in the United States and Canada was initiated in 1991. Two hundred forty-four patients eligible for such a study, by virtue of criteria extant in each institution at the time, were centrally randomized. They underwent placement of either a knitted Dacron polyester graft impregnated with collagen or a thin-wall expanded reenforced PTFE graft to the above-knee popliteal artery, usually from the common femoral artery. They were frequently observed by protocol for as long as 5 years by a physical examination noninvasive hemodynamic study, including duplex scanning in many instances. Continuing patency was noted, as were other potential adverse outcome events. The data were analyzed by the log-rank test for cumulative patency and expressed as Kaplan-Meier curves. Data were further analyzed with a Cox proportional hazards model. Results: There were no differences in graft groups in demographic or comorbid factors. The procedural mortality rate was zero, and the morbidity rate was low (6.5%). The long-term patient survival rate was excellent (77% at 3 years). At the end of these years, no statistical significance in primary or secondary patency rates was observed between the two grafts (primary patency rate, 62% ± 14.4% for Dacron; 57% ± 15.5% for PTFE). No unexpected adverse outcomes on limb status were noted. Patency rates in both graft groups were inferior in patients who received small grafts (5 to 6 mm vs 7 to 8 mm; hazards ratio, 4.15) and younger (

Introduction: The causes and management of prosthetic graft infections have been extensively studied for conventional bypass grafts; however, the infectivity and therapy for endovascular graft infections are completely unknown. The aim of this study was to compare the biologic properties of infected aortic grafts when inserted by endoluminal or standard transabdominal techniques. Methods: Eighteen dogs underwent placement of polytetrafluoroethylene grafts in their infrarenal aortas either by an endovascular technique (8) or a standard interposition technique (10). Endovascular grafts were constructed from polytetrafluoroethylene (3 cm) and two balloon-expandable stents coaxially mounted onto a balloon catheter delivery system. The grafts were inserted through a left carotid arteriotomy under fluoroscopic control. Initially, seven grafts were infected with decreasing inocula of Staphylococcus aureus, starting at 10 7 organisms per ml for 30 minutes and then rinsed briefly (10 seconds) in normal saline solution, until a 50% infective dose for the standard grafts was determined to be 10 2 organisms per ml. After this initial experiment, a second group of 11 dogs were compared at a concentration of 10 2 S. aureus per ml. Five dogs underwent endovascular repair, and six dogs had standard graft interpositions after an identical period of bacterial exposure. All grafts were removed at 2 weeks under sterile conditions and were submitted for quantitative culture analysis. Results: Three of the six dogs (50%) with standard grafts appeared to clear their infections, whereas only one of the five dogs (20%) with an endovascular graft was free of organisms at 14 days. This result was further manifested by statistically significant lower postmortem colony counts in the standard grafts ( p Conclusions: The endoluminal position of the graft and its proximity to the arterial wall do not appear to provide protection against infection. These data suggest that if endovascular grafts become infected, they may be in a disadvantaged position for host defense mechanisms to be effective. (J Vasc Surg 1996;24;920-6.)

New endovascular procedures are increasing the options available to the vascular surgeon for the treatment of arterial disease. These techniques, alone or in combination with conventional surgical techniques, may allow the safer treatment of complex aortoiliac pathology, particularly in patients with comorbid medical illnesses who have high morbidity and mortality rates associated with open surgical repair. The authors describe the successful treatment of two noninfected aortoiliac false aneurysms eight years after the original arterial reconstruction with a bifurcated graft. The pseudoaneurysms were treated by use of a combination of endovascular and standard surgical techniques in a patient with significant comorbid medical conditions that limited standard surgical repair.

Purpose: Vein graft stenosis caused by intimal hyperplasia (IH) accounts for 30% to 50% of late bypass graft failures; however, the biochemical mediators of vein graft IH have been poorly defined. We attempted to evaluate the spatial and temporal distribution of five principal cytokines (interleukin-1 beta [IL-1β], platelet-derived growth factor AA [PDGF-AA], basic fibroblast growth factor [bFGF], interferon gamma [INFγ], and tumor necrosis factor alpha [TNF-α]) during the development of IH in a rat vein graft model. Methods: Rat epigastric vein interposition grafts in the femoral artery were harvested at 6 hours, 2 days, 1 week, 2 weeks, and 4 weeks after the grafting procedure and studied with immunohistochemical and standard histologic techniques. The cytokine expression in the endothelium and media/neointima was quantified as the percentage of immunopositive cells per high-power field. Results: Maximal hyperplasia occurred 2 weeks after the grafting procedure. Peak expression of IL-1β and bFGF occurred by 2 days. PDGF-AA expression paralleled the development of IH, peaking at 2 weeks and then declining. TNF-α expression increased at 1 week and remained elevated. INFγ was seen only in control grafts. Conclusions: The coordinated early release of IL-1β and bFGF and the down-regulation of INFγ seem to trigger an inflammatory response, thereby initiating IH. The process then is propagated by the release of PDGF-AA and TNF-α, with concomitant smooth muscle cell proliferation and production of extracellular matrix. It is likely that this complex milieu of local paracrine signaling is required to generate the hyperplastic response seen in failing vein grafts. (J Vasc Surg 1996;24:463-71.)

Purpose The occurrence of neointimal hyperplasia within a stent may result in restenosis with recurrent symptoms of end-organ ischemia. This study evaluated the potential of a nonporous covering of a stent to function as a barrier to the formation of intrastent neointimal hyperplasia. Materials and Methods Twelve endovascular stent grafts were used to treat 12 high-risk patients with limb-threatening ischemia secondary to long-segment iliac artery occlusion. A 6-mm, thin-walled polytetrafluoroethylene graft was inserted and anchored to the common iliac artery with use of Palmaz stents. Each stent was covered by graft material over one-half of its length. Control angiograms obtained immediately after graft insertion were compared with follow-up angiograms obtained between 4 and 6 months after the initial procedure. On each angiogram, the region of the stent was magnified by 20x to permit computerized luminal diameter measurements. Results The mean luminal diameter within the stent was significantly greater on the covered (7.7mm ± 0.33 standard deviation) compared with the uncovered (6.7mm ± 0.85 standard deviation) portions ( P Conclusions Partially covered stents are a unique model for assessing the effects of an extrinsic stent covering on arterial healing and myointimal hyperplasia. These data suggest that a relatively nonporous covering of polytetrafluoroethylene may inhibit stent-related restenosis in iliac arteries.

We performed bilateral femoral artery dissections in a single 50 kg mongrel dog. Digital fluoroscopic arteriograms documented the luminal diameter of the left iliac and right superficial femoral arteries. Balloon thrombectomy catheter passage was performed through hemostatic sheaths by 12 surgeons. Embolectomy balloons were filled with radiographic contrast material and the balloon catheter diameter was compared with the underlying vessel diameter. The percentage of overdistention of the embolectomy balloon relative to the arterial wall was 23% +/- 5% in the iliac artery and 40% +/- 13% in the femoral artery. Over a 25-month period, we used fluoroscopically assisted thromboembolectomy to treat 21 patients with acute arterial or graft occlusions. As the balloon was gently withdrawn to extract intravascular thrombus, deformities of the compliant balloon profile caused by underlying arterial lesions were identified fluoroscopically and their locations recorded to facilitate further treatment. After initial clot removal in these 21 patients, 15 residual lesions were documented. Repeat thrombectomy (n = 8), balloon angioplasty (n = 3), and placement of intravascular stents (n = 4) eliminated all 15 lesions. Luminal continuity was successfully restored in all 21 of these patients, 10 of whom required distal open vascular reconstruction to correct existing outflow artery disease. Fluoroscopically assisted thromboembolectomy is a simple and safe method for treating acute arterial or graft occlusions in patients with diffuse arteriosclerosis. It minimizes arterial damage and blood loss during balloon thrombectomy and reduces the need for intravascular contrast agents. It also has the potential to facilitate accurate identification, localization, and treatment of significant underlying arterial lesions.

The expression of c-MYC oncoprotein in proliferating smooth muscle cells (SMCs) was analyzed in an experimental model of vein graft intimal thickening.Superficial epigastric vein grafts were inserted into the femoral arteries of male Sprague-Dawley rats. The vein grafts were harvested at 6 hr, 2 days, 1 week, 2 weeks, and 4 weeks after grafting and were rapidly frozen in liquid nitrogen. Immunohistochemical labeling and morphologic analysis of vein graft sections with a double staining technique were used to identify c-MYC/alpha SMC actin and proliferating cell nuclear antigen (PC10)/alpha SMC actin within intimal cells. c-MYC/alpha SMC actin and PC10/alpha SMC actin positive cells were quantitated in the perianastomotic area (R-1) and the body of the graft (R-2) for each time period. Total wall and intimal thickness of perfusion fixed vein grafts were measured with a computer digitized system.Intimal and total wall thickening in the R-1 region peaked at 1 week (27.4 and 579.4 microns respectively) and were significantly thicker (P0.01) than the same region at 6 hr after graft implantation (6.0 and 113.5 microns respectively). Staining for c-MYC and PC10 in R-1 was also significantly higher (P0.05) at 1 week (5.75 and 7.00 positive cells/10 cells, respectively) compared with that at 6 hr (1.5 and 1.33, respectively). The R-1 region stabilized and remodeled over the following 3 weeks, while c-MYC and PC10 staining progressively decreased. In the R-2 region, intimal thickness significantly increased (P0.05) from 6 hr (4.0 micrometers) to 1 week (12.0 micrometers) and stabilized, while total wall thickness increased throughout the first week and the difference became significant at 2 weeks (P0.05). Staining for c-MYC and PC10 paralleled the staining in R-1 with a significant peak at 1 week (P0.05).c-MYC oncoprotein is expressed early after experimental vein grafting, with peak expression at 1 week. This occurs during a period of maximal intimal thickening, SMC proliferation, and increased expression of PC10. Expression of c-myc protooncogene may contribute to the induction and regulation of SMC proliferation, producing intimal hyperplasia.

Purpose: This study was undertaken to evaluate our results of polytetrafluoroethylene (PTFE) tibial and peroneal artery bypasses done for limb salvage. Methods: Within a group of patients undergoing infrainguinal limb salvage bypasses at our institution between January 1986 and May 1995, 63 patients faced an immediate amputation, had no autologous vein on duplex examination and operative exploration, and had only a tibial or peroneal artery as an outflow vessel for bypass. Most of these patients (82%) had two or more prior ipsilateral infrainguinal bypasses. These 63 patients underwent 66 PTFE bypasses to a tibial or peroneal artery without a distal anastomotic vein cuff or an adjunctive arteriovenous fistula. Our results were then compared with those reported from infrapopliteal (crural) bypasses performed with alternate autologous vein sources or PTFE in conjunction with various recommended adjuncts. Results: The 3- and 5-year cumulative primary graft patency rates for our PTFE infrapopliteal bypasses were 39% ± 7% and 28% ± 9%, respectively. Secondary graft patency rates were 55% ± 8% and 43% ± 10% at 3 and 5 years, respectively. Limb salvage rates were 71% ± 7% at 3 years and 66% ± 8% at 5 years. Two-year actuarial patient survival rate was only 67% ± 7%. Conclusions: These results indicate that a PTFE bypass to an infrapopliteal artery remains a worthwhile option in patients without usable autologous vein. The secondary patency and limb salvage rates were acceptable in this setting and were not significantly different from the best results reported with prosthetic tibial/peroneal bypasses with distal vein cuffs or patches (74% at 1 year; 58% at 3 years), arteriovenous fistulas (71% at 1 year) or composite arm vein grafts (39% and 29% at 3 and 5 years, respectively). (J VASC SURG 1996;23:347-56.)

OBJECTIVES: Complex arterial occlusive, traumatic, and aneurysmal lesions may be difficult or impossible to treat successfully by standard surgical techniques when severe medical or surgical comorbidities exist. The authors describe a single center's experience over a 2 1/2-year period with 96 endovascular graft procedures performed to treat 100 arterial lesions in 92 patients. PATIENTS AND METHODS: Thirty-three patients had 36 large aortic and/or peripheral artery aneurysms, 48 had 53 multilevel limb-threatening aortoiliac and/or femoropopliteal occlusive lesions, and 11 had traumatic arterial injuries (false aneurysms and arteriovenous fistulas). Endovascular grafts were placed through remote arteriotomies under local (16[17%]), epidural (42[43%]), or general (38[40%]) anesthesia. RESULTS: Technical and clinical successes were achieved in 91% of the patients with aneurysms, 91% with occlusive lesions, and 100% with traumatic arterial lesions. These patients and grafts have been followed from 1 to 30 months (mean, 13 months). The primary and secondary patency rates at 18 months for aortoiliac occlusions were 77% and 95%, respectively. The 18-month limb salvage rate was 98%. Immediately after aortic aneurysm exclusion, a total of 6 (33%) perigraft channels were detected; 3 of these closed within 8 weeks. Endovascular stented graft procedures were associated with a 10% major and a 14% minor complication rate. The overall 30-day mortality rate for this entire series was 6%. CONCLUSIONS: This initial experience with endovascular graft repair of complex arterial lesions justifies further use and careful evaluation of this technique for major arterial reconstruction.

Purpose: The purpose of this study was to perform a preliminary histopathologic analysis of explanted human endovascular stented grafts from patients treated for occlusive disease. Methods: Over a 16-month period, 26 endovascular stented grafts were placed in 21 patients with limb-threatening ischemia caused by aortoiliac or femoral artery occlusive disease. All grafts were inserted through open arteriotomies remote from the region of primary disease. During the follow-up period, two patients died of preexisting heart disease 2 weeks and 7 months after grafting, and a portion of their endovascular grafts with the surrounding artery was explanted. Specimens from five other endovascular grafts were obtained during surgical revision for graft stenosis after 3 and 6 weeks and for outflow artery stenosis after 3, 5, and 6 months. All specimens were formalin fixed and studied with hematoxylin and eosin and trichrome staining and immunohistochemically for factor VIII–related antigen, alpha actin smooth muscle, macrophage antigen (MAC-387) and PC-10 (a mouse monoclonal antibody which specifically recognizes proliferating cell nuclear antigen in paraffin sections). Results: Three weeks after placement of the stented grafts, organizing thrombus was present on both surfaces of the expanded polytetrafluoroethylene (PTFE) grafts. At 6 weeks, evidence of a neointima with overlying endothelium was seen in the perianastomotic region, and 3 months after grafting it was seen 1 to 3 cm from the anastomosis. The specimen explanted at 5 months demonstrated factor VIII–positive cells 8 cm from the anastomosis. The histopathologic condition of the external capsule appeared to vary, depending on the presence or absence of an external wrap on the PTFE graft and on which layer in the arterial wall the graft was inserted. A foreign body reaction characterized by multinucleated giant cells was seen adjacent to wrapped grafts or around those placed in an intraadventitial plane. Grafts inserted within the media were surrounded by orderly, arranged, smooth muscle cells and few mononuclear cells. Extensive smooth muscle cell proliferation (PC-10 activity) was not seen within native artery atherosclerotic plaques peripherally displaced and external to prosthetic endovascular grafts. Conclusions: These preliminary observations on the healing of PTFE endovascular stented grafts in human beings demonstrate limited plaque hyperplasia and the presence of endothelial cells on the luminal surface remote from the graft-artery anastomosis. It is unclear whether this is a unique manifestation of healing in prosthetic grafts inserted within the walls of arteries. (J VASC SURG 1995;21:595-604.)

background : Endovascular stented grafts employ a new technique that blends intravascular stent and prosthetic graft technologies. These devices may be used to treat arterial aneurysms, occlusive disease, and vascular injuries. This report describes the application of stented grafts to the treatment of limb-threatening ischemia secondary to occlusive disease of the aorta, iliac, and femoral arteries. methods : Three patients with limb-threatening ischemia and severe comorbid medical illnesses were treated with transvascular stented grafts that were composed of 6-mm thin-walled polytetrafluoroethylene grafts and Palmaz balloon expandable stents. The grafts were inserted through a cutdown in an artery remote from the site of occlusion and introduced into the vascular system within 14-Fr introducer sheaths. results : Technical success was documented in all three patients with restoration of arterial continuity following stent graft deployment. Patency and limb salvage has been achieved to 1 year. One patient required further dilatation of the proximal stent at 6 weeks. Complications were limited to an iliofemoral deep vein thrombosis in one patient. conclusions : Endovascular stented grafts can be inserted to treat limb-threatening ischemia. Although these initial results are encouraging, greater experience in more patients observed for longer periods of time is necessary before this technique can be advocated for widespread use.

Purpose: The purpose of this study was to review the 91 failing polytetrafluoroethylene (PTFE) grafts that were treated at our institution over the past 12 years to better understand their cause and improve the diagnosis and treatment of these grafts. Methods: Eighty-five patients with 91 failing grafts were retrospectively reviewed. The 144 graft-threatening lesions associated with these grafts were characterized by location (inflow artery, outflow artery, anastomosis, or graft body) and treatment method used (surgery, balloon angioplasty, or thrombolysis). Results: Progression of atherosclerotic disease was the predominant cause of failing PTFE grafts with 43 inflow lesions and 83 outflow lesions, accounting for 87% of all lesions identified. Ten lesions (7%) were noted within the prosthetic grafts, whereas only eight (6%) lesions were noted at the anastomoses. Forty stenotic lesions 2 cm in length or less were treated with percutaneous transluminal balloon angioplasty, whereas 100 lesions were treated by patch angioplasty or graft extensions. The remaining four lesions, present within the prosthetic grafts, were treated with thrombolytic therapy. The 5-year cumulative patency rate for all failing PTFE grafts was 71%, whereas that of failing femoropopliteal PTFE grafts was 64%. The 5-year limb salvage rate for all failing PTFE grafts was 73%. Conclusions: The progression of inflow and outflow disease is the predominant cause of failing PTFE grafts, which suggests that this process is a more important cause of PTFE graft thrombosis than is generally recognized. Frequent PTFE graft surveillance may permit detection of some threatening lesions before graft thrombosis occurs and may help maintain and prolong graft patency. The enhanced 5-year patency and limb salvage rates for treated failing PTFE grafts compared with the known poor outcome after reinterventions for PTFE graft failure support the conclusion that surveillance of PTFE grafts is worthwhile. (J VASC SURG 1993;18:981-90.)

Purpose: To determine why some vein grafts fail, we prospectively studied the relationship between the histologic condition of the greater saphenous vein (GSV) at the time of grafting and subsequent stenosis of the vein graft. Methods: Ninety-four remnant segments of GSVs were obtained at the time of infrainguinal bypass in 91 patients and were perfusion fixed before histologic and ultrastructural examination. All bypass grafts were evaluated clinically and by duplex ultrasonography at regular intervals from 1 to 30 months after operation. All 24 grafts that developed lesions that caused thrombosis (failed grafts) or flow reduction (failing grafts) underwent arteriography and appropriate operative or other interventional correction of the causative lesion. Results: There was no significant difference in the incidence of coronary artery disease, kidney disease, hypertension, or history of smoking in patients with normally functioning and failed or failing grafts. Diabetes occurred with an increased frequency in failed or failing grafts ( p = 0.056). At the time of their insertion, GSVs that subsequently developed significant lesions had thicker walls (0.72 ± 0.33 mm) compared with normally functioning grafts (0.58 ± 21 mm; p p p p Conclusions: We conclude that GSVs with thick and calcified walls or hypercellular intima at the time of grafting are at increased risk of developing intragraft lesions that may lead to graft failure. Frequent duplex ultrasonography surveillance is particularly warranted for such high-risk grafts. (J VASC SURG 1993;18:407-15.)

Purpose: The purpose of this study was to retrospectively evaluate the effectiveness of screening for coronary artery disease before elective repair of abdominal aortic aneurysms (AAA) was performed. Methods: Results of a screening algorithm for coronary artery disease in 263 patients admitted to a single hospital for elective repair of AAA between January 1986 and December 1989 were analyzed. Patients with no coronary artery disease indicators proceeded to surgery without further workup. Patients with cardiac disease indicators underwent dipyridamole-thallium scintigraphy, and patients with angina were screened by use of cardiac catheterization; those with a recent coronary revascularization underwent no additional screening unless symptoms or electrocardiographic changes suggested an intervening event. Twenty-eight patients underwent no screen other than medical history and electrocardiogram. Results: Among 164 patients screened with dipyridamole-thallium scintigraphy, 44 patients had redistribution defects that required catheterization, and 11 of these underwent coronary revascularization. Cardiac catheterization was performed directly in 42 patients, which led to 11 revascularizations before AAA repair. Previous coronary artery bypass or percutaneous transluminal angioplasty obviated additional screening in 29 patients. Of the 263 scheduled AAA repairs, 15 were cancelled because of unacceptable operative risks, 13 for cardiac reasons. One patient died of a ruptured AAA after an uneventful coronary artery bypass. Among the 247 AAA repairs performed, there were three perioperative deaths (1.2%), all of which resulted from sudden cardiac events; three additional patients had nonfatal myocardial infarctions (1.2%), for a total cardiac complication rate of 2.4%. Conclusions: The low rate of cardiac complications in this experience affirms the effectiveness of preoperative screening and selective coronary revascularization before AAA repair. (J VASC SURG 1993;18:349-57.)

Purpose: The presence of preexisting saphenous vein lesions adversely affects graft patency. Despite careful preoperative venous duplex examination and meticulous intraoperative evaluation, clinically significant saphenous vein disease may remain undetected. We evaluated angioscopy as a means to better detect these vein lesions. Methods: Ninety saphenous vein remnants, obtained at bypass surgery, were perfusion fixed for subsequent angioscopic and histologic evaluation. The specimens were categorized by independent examiners on the basis of the angioscopic or light microscopic findings. Of the 90 vein remnants, 66 were normal by angioscopic criteria. Fifty-three (80%) of these angioscopically normal vein segments were normal histologically, and all 24 angioscopically abnormal saphenous vein remnants showed disease on microscopic examination. Results: Angioscopy correctly identified sclerotic vein segment ( n = 20) by irregular white plaques, whereas postphlebitic veins ( n = 3) demonstrated multiple lumens, fibrous strands, and thickened opaque valve cusps on angioscopic evaluation. Absence of an angioscopic lumen was confirmed histologically in occluded ( n = 2). Angioscopy failed to identify thick-walled ( n = 10) and varicose ( n = 2) vein segments as abnormal; one sclerotic segment was normal angioscopically, thereby lowering the sensitivity of angioscopy. Conclusions: Angioscopy detected unsuspected preexisting saphenous vein disease in five patients undergoing arterial reconstruction with saphenous vein. Because the use of angioscopy is a reliable means of prospectively assessing the vein for most preexisting lesions, its routine use may ultimately improve graft patency. (L V ASC S URG 1993;18:198-206.)

Background There is increasing pressure for the rapid development and implementation of new techniques and procedures. This study examined whether or not there has been a trend toward increasingly short follow-up times for studies evaluating the treatment of lower-extremity occlusive disease. Methods A search was performed of PubMed using the term “femoropopliteal occlusive disease” from 1976 to 2006. Reports describing the open and/or endovascular treatment of femoropopliteal occlusive disease were classified according to the number of patients, method of treatment, and follow-up time. Results A total of 103 of the 435 reports met the inclusion criteria. Average follow-up times from 1976 to 1986 were a mean of 43.3 months and a median of 38.8 months, from 1986 to 1996 were a mean of 32.4 months and a median of 16.9 months, from 1996 to 2006 were a mean of 22.6 months and a median of 16.5 months. Conclusions The number of reports on femoropopliteal occlusive disease treatment has increased. The length of follow-up period was 2- to 3-fold longer for reports on open procedures compared with those on endovascular procedures. Whether length of follow-up evaluation and reporting intervals should be standardized warrants further investigation.

Background It has been well established that inferior vena cava (IVC) filter placement at the time of open gastric bypass (OGB) surgery in patients with a body mass index of more than 55 kg/m 2 reduces both the pulmonary embolism rate and the perioperative mortality. However, little is known about the long-term effects of IVC filter placement in this particular group of patients. Methods Over an 8-year period, a total of 571 morbid obese patients underwent OGB procedures, and 58 (10%) of them required placement of an IVC filter before their procedure. All IVC filters were placed percutaneously through a femoral vein approach using a portable OEC fluoroscope. Types of IVC filters used in our study included the TrapEase ( n = 35), Simon-Nitinol ( n = 9), Greenfield ( n = 2), and Bard Recovery ( n = 12). Results Of the 58 patients who required an IVC placement, 56 remained free of any thromboembolic phenomena over the 8-year period (range, 1-8 years). The remaining two patients developed deep venous thrombosis. One patient was successfully treated with intravenous heparin and a 6-month course of Coumadin. She had complete resolution of her deep venous thrombosis and was incidentally noted to have a prothrombin 20210 gene mutation. The other patient, who had multiple gastric bypass complications, could not be successfully treated with intravenous heparin and thus progressed on to complete IVC thrombosis. She developed phlegmasia cerulea dolens and required bilateral above-the-knee amputations. She subsequently died 3 months after her procedures. Conclusion It appears that IVC filter placement at the time of OGB surgery is a relatively benign intervention with a maximal benefit. A note of caution should be exerted for those obese patients who have a hypercoagulable disorder and for those who have complications related to the gastric bypass. An aggressive posture, which may consist of immediate anticoagulation after their procedures (only when it is deemed safe), should be advocated in this small sub-group of morbid obese patients.