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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.amjsurg.2009.09.003 Byline: Rebekah A. Naylor, Lisa A. Hollett, Antonio Castellvi, R. James Valentine, Daniel J. Scott Keywords: Skills; Curriculum; Medical students; Surgery internship; Proficiency-based Abstract: This study was designed to develop and evaluate an integrated cognitive and proficiency-based skills curriculum based on American College of Surgeons Graduate Medical Education Committee (ACGME) competencies to prepare students for surgery internships. Author Affiliation: Department of Surgery, Southwestern Center for Minimally Invasive Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9156, USA Article History: Received 29 June 2009; Revised 24 August 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.amjsurg.2008.07.008 Byline: Todd Cumbie, Eric B. Rosero, R. James Valentine, J. Gregory Modrall, G. Patrick Clagett, Carlos H. Timaran Keywords: Duplex ultrasonography; Carotid stenting; In-stent restenosis Abstract: Stents alter flow velocities after carotid artery stenting (CAS). To identify criteria for in-stent restenosis (ISR), velocities obtained by duplex ultrasonography (DU) after CAS were analyzed. Author Affiliation: Division of Vascular and Endovascular Surgery, Department of Surgery, University of Texas Southwestern Medical Center and Dallas Veterans Affairs Medical Center, Dallas, TX, USA Article History: Received 12 May 2008; Revised 9 July 2008

Carotid endarterectomy is a surgical procedure to remove fatty plaque that has accumulated along the inner lining of the carotid artery, one the main blood supplies to the brain. Computed tomographic (CT) scanning, used to evaluate patients prior to carotid endarterectomy, has been able to identify patients with clinically undetectable cerebral infarction (death of brain tissue due to loss of blood supply). Patients with such ''silent'' cerebral infarcts have increased incidence of neurologic complications. This finding has prompted some authors to recommend routine CT scanning prior to endarterectomy. A study over a five-year period of 469 patients about to undergo endarterectomy was undertaken to ascertain the usefulness of routine CT scans in preoperative evaluation. Prior to surgery all patients underwent CT scan and carotid duplex scan (a type of ultrasound study that is useful in monitoring blood flow). Of the patients in the study, 237 had suffered transient ischemic attacks (TIAs, or episodes of cerebrovascular insufficiency usually with partial occlusion of an artery); 109 had prior stroke (a sudden loss of consciousness followed by paralysis); and 122 patients were without symptoms. Sixty-two percent of the stroke patients had abnormal CT scan results. CT scan did not reveal any unsuspected cerebral infarctions or tumors. Twenty-three percent of the patients who were operated upon had abnormal CT findings, which did not influence any surgical decisions. Among the patients who were not operated on, 27 percent had abnormal CT scans, which were not the reason surgery was not performed. There were three perioperative stokes. Postoperative neurologic complications were correlated with CT findings. In this study, routine use of CT scanning (costing half a million dollars) was not cost-effective. It is concluded that CT scanning prior to carotid endarterectomy should not be performed on a routine basis. (Consumer Summary produced by Reliance Medical Information, Inc.)

Study Design: Retrospective study.Objective: Previous studies have demonstrated that increased implant density (ID) results in improved coronal deformity correction. However, low-density constructs with strategically placed fixation points may achieve similar coronal correction. The purpose of this study was to identify key zones along the spinal fusion where high ID statistically correlated to improved coronal deformity correction. Our hypothesis was that high ID within the periapical zone would not be associated with increased percent Cobb correction.Methods: We identified patients with Lenke type 1 curves with a minimum 2-year follow up. The instrumented vertebral levels were divided into 4 zones: (1) cephalad zone, (2) caudal zone, (3) apical zone, and (4) periapical zone. High and low percent Cobb correction groups were compared, high percent Cobb group was defined as percent correction >67%. Total ID, total concave ID, total convex ID, and ID within each zone of the curve were compared between the groups. A multivariable analysis was performed to identify independent predictors for coronal correction. Subsequently increased and decreased thoracic kyphosis (TK) groups were compared, increased TK was defined as post-operative TK being larger than preoperative TK and decreased TK was defined as post-operative TK being less than preoperative TK.Results: The cohort included 68 patients. The high percent Cobb group compared with the low percent Cobb group had significantly greater ID for the entire construct, the total concave side, the total convex side, the apical convex zone, the periapical zone, and the cephalad concave zone. The high percent Cobb group had greater pedicle screw density for the total construct, total convex side, and total concave side. In the multivariate model ID and pedicle screw density remained significant for percent Cobb correction. Ability to achieve coronal balance was not statistically correlated to ID (P= .78).Conclusions: Increased ID for the entire construct, the entire convex side, the entire concave side, and within each spinal zone was associated with improved percent Cobb correction. The ability to achieve coronal balance was not statistically influence by ID. The results of this study support that increasing ID along the entire length of the construct improves percent Cobb correction.

Study Design: Retrospective.Objective: Identify patient risk factors for extended length of stay (LOS) and 90-day hospital readmissions following elective anterior cervical discectomy and fusion (ACDF).Methods: Included ACDF patients from 2013 to 2017 at a single institution. Eligible patients were subset into LOS <2 and LOS ≥2 days, and no 90-day hospital readmission and yes 90-day hospital readmission. Patient and surgical factors were compared between the LOS and readmission groups. Multivariable logistic regression analysis was utilized to determine the association of independent factors with LOS and 90-day readmission rates.Results: Our sample included 1896 patients; 265 (14%) had LOS ≥2 days, and 121 (6.4%) had a readmission within 90 days of surgery. Patient and surgical factors associated with LOS included patient age ≥65 years (odds ratio [OR] 1.72, 95% confidence interval [CI] 1.15-2.56), marriage (OR 0.57, 95% CI 0.43-0.79), private health insurance (OR 0.28, 95% CI 0.15-0.50), American Society of Anesthesiologists (ASA) score (OR 1.52, 95% CI 1.12-1.86), African American race (OR 1.95, 95% CI 1.38-2.72), and harvesting iliac crest autograft (OR 4.94, 95% CI 2.31-10.8). Patient and surgical factors associated with 90-day hospital readmission included ASA score (OR 1.81, 95% CI 1.32-2.49), length of surgery (OR 1.002, 95% CI 1.001-1.004), and radiculopathy as indication for surgery (OR 0.60, 95% CI 0.39-0.96).Conclusions: Extended LOS and 90-day hospital readmissions may lead to poorer patient outcomes and increased episode of care costs. Our study identified patient and surgical factors associated with extended LOS and 90-day readmission rates. In general, preoperative patient factors affected these outcomes more than surgical factors.

Background: Numerous clinical conditions have been proposed to explain the premature onset of symptomatic peripheral vascular disease (PVD) in young adults, but the role of genetic factors has not been defined. This study was performed to determine the prevalence of cardiovascular disease among family members of patients with premature PVD. Methods: The prevalence of early cardiovascular events occurring in first-degree relatives of 90 subjects with premature PVD (onset [is less than or equal to] 49 years) was determined. The prevalence of occult atherosclerosis was determined by duplex ultrasonography in a cohort of 20 asymptomatic siblings. Reference groups included first-degree relatives of 80 subjects with premature coronary artery disease (CAD) and first-degree relatives of 48 healthy subjects. Results: Cardiovascular events occurred at age 55 years or younger in 28% of the parents of PVD subjects, in 23% of parents of CAD subjects, and in 7% of the parents of healthy controls (P [is less than] .001). Cardiovascular events occurred in 24% of siblings of PVD subjects, in 14% of siblings of CAD subjects, and in 7% of siblings of healthy controls (P [is less than] .001). Duplex ultrasonography detected early plaques in the lower extremity circulation of 10 (50%) of the asymptomatic siblings of PVD subjects. Conclusions: Early, symptomatic cardiovascular disease is more common in first-degree relatives of individuals with premature PVD than in relatives of healthy individuals or of probands with premature CAD. Occult vascular disease in the lower extremity is prevalent among asymptomatic siblings of probands with premature PVD. These observations indicate that susceptibility to premature PVD has a familial basis. Arch Intern Med. 2000;160:1343-1348

I enjoyed 'A War Worth Fighting' (2/27). We do our communities a disservice when we lump addiction, mental illness and all the other causes of poverty together. Our children are [...]

Heat stress (HS) causes morbidities and mortalities, in part by inducing organ-specific injury and dysfunction. Further, HS markedly reduces farm animal productivity, and this is especially true for lean tissue accretion. The purpose of this investigation was to determine the extent to which short-term HS caused muscle dysfunction in skeletal muscle. We have previously found increased free radical injury in skeletal muscle following 24 h of HS. Thus, we hypothesized that HS would lead to apoptosis, autophagy, and decreased mitochondrial content in skeletal muscle. To test this hypothesis, crossbred gilts were divided into 3 groups (n= 8/group): thermal neutral (TN: 21°C), HS (37°C), and pair-fed thermal neutral (PFTN: feed intake matched with heat-stressed animals). Following 12 h of treatment, animals were euthanized and red (STR) and white (STW) portions of the semitendinosus were recovered. Heat stress did not alter intracellular signaling in STW. In STR, the oxidative stress marker malondialdehyde protein and concentration were increased in HS (P= 0.007) compared to TN and PFTN, which was matched by an inadequate antioxidant response, including an increase in superoxide dismutase (SOD) I (P= 0.03) and II relative protein abundance (P= 0.008) and total SOD activity (P= 0.02) but a reduction (P= 0.006) in catalase activity in HS compared to TN. Further, B-cell lymphoma 2–associated X protein (P= 0.02) and apoptotic protease activating factor 1 (P= 0.01) proteins were increased by HS compared to TN and PFTN. However, caspase 3 activity was similar between groups, indicating a lack of apoptotic execution. Despite increased initiation, autophagy appeared to be inhibited by HS as the microtubule-associated protein A/B light chain 3 II/I ratio and mitofusin-2 proteins were decreased (p< 0.03) and sequestosome 1(p62) protein abundance was increased (P= 0.001) in HS compared to TN and PFTN. Markers of mitochondrial content cytochrome c, cytochrome c oxidase IV, voltage-dependent anion channel, pyruvate dehydrogenase, and prohibitins 1 were increased (P< 0.05) in HS compared to TN, whereas mitochondrial biogenesis and mitophagy markers were similar between groups. These data demonstrate that HS caused aberrant intracellular signaling, which may contribute to HS-mediated muscle dysfunction.

Disparate outcomes in critical limb ischemia (CLI) persist between ethnicities. The contribution of modifiable factors versus intrinsic biologic differences remains unclear. Hence, we aimed to quantify the associations between ethnicity and anatomic patterns of arterial occlusive disease in CLI, adjusting for known atherosclerotic risk factors.

Introduction Sonographic detection of incompetence in the deep and superficial veins requires proper patient positioning. Although these tests have been traditionally performed in the reversed Trendelenburg (RT) position, recent mandates from The Intersocietal Commission for the Accreditation of Vascular Laboratories and some insurance providers require that patients be evaluated for reflux in the standing position (SP). The purpose of this study was to determine whether performing venous duplex in the SP versus RT position adds information that affects patient treatment.Methods Twenty-eight subjects (25 women; mean age of 52 years) with signs and symptoms of venous insufficiency were evaluated prospectively with the use of ultrasound imaging and Doppler in the 5- to 8-MHz ranges. The great saphenous vein (GSV) was evaluated for each limb from below the knee to the saphenofemoral junction. Patients were initially evaluated at 15–25 degrees of RT position. Reflux was defined by reversal of flow for >0.5 seconds via use of the Valsalva and/or manual compression maneuvers. The GSV was measured in A-P diameter at the saphenofemoral junction and at the knee level. The subjects were then elevated to SP and measurements were repeated while the limb was in a nonweight-bearing position.Results A total of 52 limbs were evaluated for venous reflux in 28 study subjects. The mean lower-extremity CEAP score was 3 SD ± 3. Twenty-six (50%) GSVs were positive for venous reflux in the RT position. Of these GSVs, three were negative for reflux in SP. Twenty-seven (53%) GSVs were positive for venous reflux in SP; however, four of these GSVs were negative for reflux in RT. The median difference in reflux time from RT to SP was 0.15 seconds (interquartile range 0–3.8 seconds and 0–2.7seconds, respectively, p= 0.02). The mean difference in GSV diameter from RT to SP was 0.7 mm (±0.96 mm SD, p< 0.0001). These results changed the clinical course for one subject who did not have reflux in RT but did in SP (3.5%, p= 0.085).Conclusion The results from evaluating subjects in SP were not independently associated with a change in clinical outcome. However, 15% of GSVs negative for reflux in RT were positive for reflux in the SP. As a result, 3.5% of subjects in our study had a change in clinical course as the result of evaluation of the GSV in SP. This finding suggests that failure to identify GSV reflux in RT in patients with signs and symptoms of venous insufficiency may be an indication to evaluate the GSV in SP.

Purpose: To determine the most accurate method of assessing clot lysis after percutaneous mechanical thrombectomy for iliofemoral deep vein thrombosis (DVT) and to evaluate the effectiveness of two different pharmacomechanical thrombectomy devices.Methods: Between 2004 and 2009, 33 patients (18 women; mean age 47 years) with iliofemoral DVT underwent pharmacomechanical thrombectomy using the AngioJet (n = 18) or Trellis (n = 15) devices with 10 mg of tenecteplase. Intravascular ultrasound (IVUS) and venography were performed over the iliofemoral segments before and after treatment. Cross-sectional vessel and lumen diameters were measured from the IVUS scans and the post-procedure anteroposterior and lateral venograms at 3 points (proximal, mid-section, and distal) along each iliofemoral vein by 2 independent observers blinded to the treatment method. Volumes of the recanalized segments were calculated and compared to volumes of the original venous segments to assess clot lysis with each PMT device. IVUS scans and venograms were also compared for their ability to identify residual lesions or clot in need of treatment. Repeatability between and among observers was analyzed using the Bland and Altman method.Results: All procedures were successfully completed; there were only 2 minor bleeding complications. The mean volume of the recanalized segment was 2255±66 mm3by IVUS, representing 80% lysis of the clot compared to what was perceived as >90% lysis with venography (p<0.05). IVUS was able to delineate significant residual thrombus, stenosis, or May-Thurner anatomy requiring ancillary interventions in 100% of patients versus 48% (16/33) on the venograms (p<0.01). Quantitative assessments of the diameters of the involved venous segments from the venograms and IVUS were consistent between and among observers. Comparing the similar patient subgroups, AngioJet resulted in greater clot lysis (88%) versus the Trellis device (72%; p<0.01), corresponding to recanalized venous segment volumes of 2486±74 and 2025±57 mm3and total venous segment volumes of 2826±84 and 2813±79 mm3, respectively.Conclusion: IVUS is superior to venography for detection of residual thrombus and underlying venous pathology after pharmacomechanical thrombectomy. While greater clot lysis was seen with the AngioJet system, both the AngioJet and Trellis devices resulted in excellent clinical clot lysis.

Informes anteriores sugieren que el abordaje percutáneo para el tratamiento endovascular de los aneurismas de aorta abdominal (TEVA-P) es tan seguro como el abordaje abierto (TEVA-A) en pacientes con una anatomía femoral favorable. La calcificación severa de la arteria femoral y la obesidad han sido consideradas contraindicaciones relativas del TEVA-P, pero estos criterios no se han evaluado. El objetivo de este estudio fue evaluar los cambios anatómicos postoperatorios asociados con el TEVA-P frente al TEVA-A utilizando la reconstrucción mediante tomografía computarizada (TC) tridimensional (3D) y evaluar los resultados globales de ambas intervenciones en un grupo de pacientes con una anatomía femoral subóptima. Durante un período reciente de 26 meses, 173 pacientes fueron sometidos a TEVA en nuestros centros, incluidas 35 TEVA-P. Se obtuvieron imágenes de las arterias femorales mediante TC completas pre y postoperatorias en 22 de ellos (63%). Estos individuos se compararon con 22 controles emparejados que fueron sometidos a una TEVA-A durante el mismo período. Se utilizaron reconstrucciones 3D automatizadas para determinar los siguientes parámetros anatómicos de la arteria femoral antes y después del TEVA: profundidad arterial, puntuación de la calcificación, diámetro y área mínimos, diámetro y área máximos. De las 88 arterias estudiadas, 50 fueron sometidas a abordaje abierto y 38 a abordaje percutáneo (Proglide, n = 11; Prostar XL, n = 27). Ambos grupos fueron similares con respecto al tamaño del introductor, número de componentes, tiempo de intervención, pérdida de sangre y duración de la hospitalización. Un número significativamente mayor de individuos sometidos a TEVA-A sufrieron complicaciones inguinales (p = 0,02), entre las que destacaron 5 hematomas, 2 infecciones de la herida, 2 trombosis femorales, y un vaso que requirió una corrección con parche. En el grupo TEVA-P solamente se produjo un hematoma, que se trató de forma conservadora. No se observaron diferencias entre los grupos TEVA-P y TEVA-A con respecto a la calcificación de la arteria femoral (puntuación de la escala de Agatston 667 ± 719 frente a 945 ± 1.248, p = 0,37). Seis pacientes tanto del grupo TEVA-P como del TEVA-A (27%) presentaron obesidad (índice de masa corporal > 30) (p = no significativa). Los datos anatómicos obtenidos de las TC pre y postoperatoria mostraron una reducción significativa del área vascular minima con el TEVA-A en comparación con el TEVA-P (p = 0,02). Este estudio demuestra que los pacientes con obesidad o calcificación severa de las arterias femorales pueden ser tratados satisfactoriamente de forma percutánea presentando solamente complicaciones inguinales leves.

A series of hydrogels were formed from the reaction between an amine functionalized succinyl chitosan and an oxidized dextran. The properties and rate of formation of the gel were related to both the amine and aldehyde levels of the precursors. These levels could be readily changed by altering the reaction conditions, and allowed good control of the gel properties. Oxidation of the dextran with periodate was accompanied by chain scission and a large reduction in molecular weight. The gel showed excellent haemostatic properties and reduction of adhesions in animal models.

OBJECTIVE To determine whether variables in the surgery resident selection process will predict attrition or performance during residency training. DESIGN Retrospective study. SETTING A university residency program. PARTICIPANTS A total of 111 categorical surgery residents matched during a 10-year period (1991-2000). MAIN OUTCOME MEASURES Satisfactory outcome included successful completion of training and the American Board of Surgery examinations on the first attempt. Participants with a satisfactory outcome were stratified into good or marginal performance based on adverse actions during residency. RESULTS Of 111 residents studied, 28 (25.2%) had an unsatisfactory outcome; attrition occurred in 25 (22.5%). Univariate analysis identified the following variables as predictors of unsatisfactory outcome: age at entry older than 29 years (P = .005), female sex (P = .02), courses repeated (P = .01), “C” grades on transcript (P = .01), no participation in team sports (P = .02), and lack of superlative comments in the dean's letter (P = .03). The following variables were retained in the multivariate model: age older than 29 years (odds ratio [OR], 0.11; 95% confidence interval [CI], 0.02-0.47; P = .003), summary comments in the dean's letter (OR, 4.57; 95% CI, 2.00-10.43; P &lt; .001), participation in team sports (OR, 4.96; 95% CI, 1.36-18.05; P = .02), and merit scholarship in medical school (OR, 0.25; 95% CI, 0.08-0.78; P = .02). CONCLUSIONS Attrition can be predicted from factors identified on residency applications, with nonacademic factors being more important. Among residents who completed the program, no predictors of performance were identified.Arch Surg. 2008;143(7):647-652--

BACKGROUND A randomized clinical trial from the United Kingdom (EVAR trial 2) comparing endovascular aortic aneurysm repair (EVAR) with no intervention found no advantage for EVAR in patients with high risk. This finding was predominantly caused by the substantial in-hospital mortality after EVAR (9%). HYPOTHESIS The nationwide in-hospital mortality for patients with the highest risk undergoing EVAR in the United States is lower than that reported in EVAR trial 2. DESIGN Population-based, cross-sectional study. SETTING The 2001-2004 Nationwide Inpatient Sample. PATIENTS AND METHODS The Nationwide Inpatient Sample identified EVAR procedures for nonruptured abdominal aortic aneurysms. Risk stratification was based on comorbidities and the Charlson comorbidity index, a validated predictor of in-hospital mortality after abdominal aortic aneurysms repairs. Weighted univariate and logistic regression analyses were used to determine the association between comorbidity measures and risk-adjusted in-hospital mortality. RESULTS During the 4-year period, 65 502 EVARs were performed with an in-hospital mortality of 2.2%. Risk-adjusted in-hospital mortality rates ranged from 1.2% to 3.7%. Stratified analyses, including only elective EVAR procedures, revealed that in-hospital mortality was significantly higher in patients with the most severe comorbidities (1.7%) vs those with lower comorbidity (0.4%; P&lt;.001). Patients with high risk had only a 1.6-fold increased risk of adjusted in-hospital mortality (odds ratio, 1.6; 95% confidence interval, 1.2-2.2) compared with patients with low risk. CONCLUSIONS The EVAR procedure is currently being performed in the United States with low in-hospital mortality, even in patients with the highest risk. Therefore, EVAR should not be denied to high-risk patients with abdominal aortic aneurysms in the United States on the basis of the level I evidence from the United Kingdom study.Arch Surg. 2007;142:520-525--

OBJECTIVE To evaluate percutaneous mechanical thrombectomy for deep venous thrombosis (DVT). DESIGN A retrospective analysis. SETTING Tertiary academic medical center. PATIENTS Thirty patients with DVT who underwent percutaneous mechanical thrombectomy. INTERVENTIONS Percutaneous mechanical thrombectomy of upper or lower extremity DVT. MAIN OUTCOME MEASURES Thrombus removal, patency, and valvular function. Venography and intravascular ultrasonography assessed periprocedural lysis. Duplex ultrasonography assessed patency and valvular function before and after the procedure. RESULTS Fourteen patients had iliofemoral, 6 had iliofemoropopliteal, 5 had femoropopliteal, and 5 had subclavian vein thromboses. Mean age was 50.9 years (range, 15-78 years); 10 patients (33%) had a documented hypercoagulable state. There was 100% technical success in crossing the DVT, with treatment performed in a single setting in 24 patients (80%). Mean ± SD procedural time was 145 ± 35 minutes; range, 55-210 minutes. Mean thrombolytic dose was 6.2 mg of tenecteplase with the Trellis-8 and 10 mg with the AngioJet. Adjunctive procedures were required in 28 patients (percutaneous transluminal angioplasty and stent placement in 17 and percutaneous transluminal angioplasty alone in 11). Recoverable inferior vena cava filters were placed in 21 patients and retrieved within 4 weeks. There were no clinically significant periprocedural pulmonary emboli; however, 5 patients (17%) had evidence of pulmonary embolism on computed tomographic angiography (all in patients without inferior vena cava filters). Venous patency was maintained in 27 patients (90%) and lower extremity valvular function was maintained in 22 (88%) of 25 treated lower limbs, with a mean follow-up of 6.2 months (range, 3-24 months). CONCLUSIONS Percutaneous mechanical thrombectomy is effective in the treatment of acute DVT in the upper and lower extremity to restore venous patency. In the lower extremity, valvular function is maintained acutely. Continued surveillance and follow-up will be necessary to determine whether valvular function is maintained long-term.Arch Surg. 2007;142:513-519--

The technique of sentinel node biopsy (SNB) may be used as a staging technique for cancer patients. SNB involves the localization of lymph nodes that have accumulated a radioactive tracer, and this requires surgeons to gain and demonstrate skills in the use of hand-held radiation detectors (gamma probes).

: Revascularization of brachiocephalic arteries with prosthetic graft offers excellent patency for most reconstructions. For complex brachiocephalic reconstructions, such as redo operations or reconstructions for infection, autogenous conduit may be preferable. Occasionally saphenous vein is inadequate or absent. The purpose of this study was to evaluate the indications and intermediate-term outcomes of superficial femoral-popliteal vein (SFPV) as an alternative conduit for brachiocephalic reconstructions. Over a 6-year period, 71 patients underwent carotid, subclavian, or axillary artery bypass. In 18 (25%) of these reconstruction SFPV was used as the conduit. Ten bypasses (55%) were redo operations. Three bypasses (17%) were performed after failed prosthetic grafts. Three grafts (17%) were required in infected patients. Indications for the use of SFPV included inadequate saphenous vein (n = 13), infection (n = 3), and failed prosthetic bypass (n = 3). Thirty-day mortality was 5.5%. The neurologic event rate was 5.5%. During a mean follow-up of 26 ± 5 months, there were no graft thromboses or graft infections. Revision-free primary patency was 92% at 48 months. Assisted primary patency was 100%. These data suggest that SFPV is a safe, durable conduit for brachiocephalic reconstructions. SFPV yielded excellent results for a disadvantaged patient population.

An efficient resolution process using N-methyl glucamine (meglumine) which directly provides (S)-etodolac as the meglumine salt is described. This salt is also a dosage form with improved absorption characteristics. The off-isomer is efficiently racemised via the ester, prepared by mild esterification, followed by hydrolysis affording rac-etodolac suitable for recycling.

Objective: The onset of symptomatic peripheral arterial disease at a young age (premature PAD) has been associated with rapid progression, bypass graft failure, and amputation. This study was performed to document the incidence of these complications and to determine the risk factors for poor outcome in patients with premature PAD. Methods: This study was designed as a prospective longitudinal analysis, with patients who were ambulatory or hospitalized at a single vascular referral institution. The subjects were 51 white men with onset of PAD symptoms before the age of 45 years (mean age of onset, 41 +/- 0.5 years) and represented consecutive patients who were seen at the vascular surgery service during a 4-year period. Thirty of the study subjects (58%) were recruited during the first 2 years. The main outcome measures were number and type of lower extremity revascularization procedures or amputations that were necessitated during the follow-up period. Results: During a mean follow-up period of 73 +/- 6 months, 15 patients (29%) had PAD that remained stable without interventions and 15 (29%) had PAD that remained stable for a mean of 76 +/- 13 months after a single intervention. Twenty-one patients (41%) required multiple operations or major amputations. In a comparison of the 30 PAD patients whose conditions were stable with or without a single intervention with the 21 PAD patients who required multiple interventions (REDO), there were no differences in smoking, hypertension, diabetes, or dyslipidemias. The REDO group had a younger mean age at the onset of symptoms (39 +/- 1 years vs 43 +/- 2 years; P < .001). At entry, the REDO patients had a higher prevalence of infrainguinal or multilevel disease (57% vs 20%; P = .03), a lower mean ankle brachial index (0.44 +/- 0.04 vs 0.56 +/- 0.03; P = .02), and more frequent tissue loss (24% vs 0; P = .005). The REDO patients had a higher mean lipoprotein (a) level than did the patients with stable conditions (51 +/- 11 mg/dL vs 27 +/- 5 mg/dL; P = .03), but there were no significant differences in the mean plasma homocysteine levels (19 +/- 2 @mmol/L vs 16 +/- 1 @mmol/L) or in the proportion of patients with hypercoagulable states (33% vs 30%). The only predictive variables that were selected with stepwise logistic regression analysis were age at onset (P < .002; odds ratio, 1.4; 95% confidence interval, 1.11 to 1.81) and ankle brachial index of less than 0.5 (P < .008; odds ratio, 6.4; 95% confidence interval, 1.5 to 27.3). Conclusion: Although 60% of the white men with premature PAD who were referred to a vascular surgery service had conditions that appeared to remain stable, these data show that approximately 40% of the patients will require multiple interventions because of disease progression or bypass graft failure. Clinical indicators, not serum markers, are predictors of poor outcome in patients with premature PAD. The results of this study suggest that patients with onset of PAD before the age of 43 years who have objective evidence of advanced disease are predisposed to multiple interventions. (J Vasc Surg 1999;30:436-45.)

Purpose: The superficial femoral-popliteal vein (SFPV) is a reliable conduit for aortoiliac, infrainguinal, and venous reconstructions. In this prospective study, we characterized the anatomic and physiologic changes in SFPV harvest limbs and their relationship to the development of late venous complications. Methods: Since 1990, we have studied 61 patients after harvest of 86 SFPVs at 6-month intervals with clinical examinations, lower-extremity venous duplex, and venous function tests. The CEAP system was used as a means of categorizing clinical changes. Results: Mean (+/- SEM) follow-up was 37 +/- 3 months. Less than one third of harvest limbs had edema without skin changes (C"3). No patient had major chronic venous changes (C"4 to C"6) or venous claudication. There were no significant differences in limb measurements between harvest and non-harvest limbs, except in a subgroup of patients with unilateral harvest in which there was a small but significant (P = .046) increase in harvest limb thigh and calf circumference, compared with the opposite non-harvest limb. These clinical results were not affected by the presence or absence of an intact greater saphenous vein (GSV). Large, direct collaterals (4 to 6 mm in diameter) between the popliteal vein stump and profunda femoris vein (PFV) were seen by means of duplex ultrasonography in 29 harvest limbs (34%). The remainder appeared to have smaller, less direct collaterals to the PFV. Mild venous reflux with rapid cuff deflation was present at the popliteal or posterior tibial vein in nine of 79 harvest limbs (11%). Six of these nine limbs (67%) with reflux were clinical class C"3, compared with only 19 of the 70 limbs without reflux (27%; P = .02). Ambulatory venous pressure (AVP) with exercise was significantly increased in harvest limbs (60 +/- 4.7 mm Hg), compared with non-harvest limbs (47.8 +/- 5.2 mm Hg; P = .049). The AVP recovery time of harvest limbs (14.0 +/- 1.0 seconds) was reduced, compared with non-harvest limbs (23.5 +/- 4.5 seconds; P = .02). AVPs (exercise) remained stable or decreased in six of 10 harvest limbs measured serially. Venous refill time in harvest limbs (15.1 +/- 1.1 seconds) was shortened, compared with non-harvest limbs (22.3 +/- 2.1 seconds)(P = .002). Venous outflow obstruction measured by means of plethysmography was present in 93% of harvest limbs, compared with 36% of non-harvest limbs (P = .001). Conclusion: SFPV harvest results in minimal mid-term to late-term lower-extremity venous morbidity despite outflow obstruction. The most likely mechanisms preserving clinical status include the low incidence of mild reflux, the presence of collateral venous channels, and the lack of progression in abnormal harvest limb physiology. The absence of the ipsilateral GSV does not adversely affect clinical outcome. (J Vasc Surg 1999;29:282-91.)

Purpose: The net benefit of routine intraoperative autotransfusion (IAT) in patients undergoing elective infrarenal aortic surgery was studied. Methods: One hundred patients undergoing abdominal aortic aneurysm (AAA) repair (n = 50) or aortofemoral bypass (AFB) for occlusive disease (n = 50) were randomized to IAT and control groups. This experience accounted for 58% of patients undergoing aortic surgery during the 16-month study period. Results: IAT and control groups were balanced for preoperative demographics, disease (50:50 split of AFB:AAA in each group), and risk factors. There were no significant differences between patients randomized to IAT and control patients in estimated blood loss (EBL), allogeneic blood transfusion (units administered intraoperatively, postoperatively, and total), proportion of patients not receiving allogeneic blood (34% of patients randomized to IAT and 28% of control patients), postoperative hemoglobin/hematocrit levels, and complications. IAT did not reduce allogeneic blood transfusion among all patients undergoing aortic surgery nor in any subgroups that might be more likely to benefit, such as those undergoing AAA repair, those with 1000 mL or more EBL, and those receiving larger volumes of IAT-processed blood. Conclusion: We could find no net benefit of IAT in patients undergoing elective, infrarenal aortic surgery. (J Vasc Surg 1999;29:22-31.)

Previous fundamental work on the solvent properties of carbon dioxide by the research groups of McHugh, DeSimone, Johnston, and Eckert has been used as a road map for the design of materials that will be miscible with CO2 at relatively moderate pressures. In this initial work, judicious side chain functionalization of an oligomeric silicone has been shown to produce a material whose phase behavior in CO2 resembles that of a fluorinated polyether. The phase behavior results are quite dramatic in that addition of only five ester-functional side chains to the silicone polymer lowers the cloud point curve at 22 °C by 2500 psi. It was also observed that addition of simple alkyl side chains raises the cloud point pressures of the silicone in CO2. This latter observation is consistent with results on the phase behavior of poly(n-alkyl acrylates) in CO2 that showed that increasing alkyl content (i.e., increasing alkyl chain length) also raises cloud point pressures.

Methylamine (MA) is a colorless gas with many industrial applications, including that as an intermediate in the manufacture of many chemicals. To assess the toxicity of MA following inhalation, groups of 10 male rats each were exposed by nose-only inhalation 6 h/d, 5 d/wk for 2 wk to either 0 (control), 75, 250, or 750 ppm MA. Rats were sacrificed either immediately following exposure or following a 14-d recovery period. Parameters investigated included in-life observations and body weights, clinical pathology, and histopathology with organ weights. Toxic effects including mortality were produced by exposure to 750 ppm. Severe body weight losses, clinical pathologic changes suggestive of liver damage, nasal degenerative changes, and hemato-poietic changes, not all of which were reversible during the recovery period, were observed. Exposure to 250 ppm produced damage, restricted to the respiratory mu-cosa of the nasal turbinates. Only a mild irritation to the nasal turbinate area was produced by 75 pprn MA.

Purpose: To demonstrate the feasibility of venous reconstructions with the superficial femoral-popliteal vein (SFPV). Methods: Seven patients who underwent a variety of major venous reconstructions using SFPV were reviewed in a retrospective, observational study. Results: Three central venous reconstructions (thoracic and abdominal) and four peripheral major venous reconstructions were performed with SFPV autografts. In all patients, the SFPV grafts provided an excellent size match and were of adequate length without the need for enlargement by paneling or spiraling techniques. Postoperative anticoagulation medication was not used. There were no early graft failures, and patency was documented by duplex ultrasound, venogram, or both in all patients at a mean of 20 months follow-up. Venous thromboembolism has not occurred, and lower extremity venous morbidity has been minimal. Conclusions: The SFPV graft demonstrates versatility and durability in selected patients who require large-caliber conduits for venous reconstruction. Because of its size and availability, the SFPV is an excellent conduit for major venous reconstruction. (J Vasc Surg 1997;26:829-37.)

The majority of proximal anastomotic complications of aortofemoral bypass grafts are related to the formation of pseudoaneurysms or true proximal aneurysmal dilation of the residual infrarenal aorta. The late development of occlusive disease at the proximal anastomosis is an extremely rare event. We report two patients in whom symptomatic stenoses developed involving the proximal anastomoses of aortofemoral bypass grafts originally placed for aortoiliac occlusive disease. Surgical exploration demonstrated the presence of a constricting prosthetic corset wrapped around the proximal suture line of each graft. Exuberant neointimal hyperplasia was responsible for both stenoses. (J Vasc Surg 1997;26:138-41.)

Purpose: To evaluate the routine use of pulmonary artery catheters (PAC) in patients who undergo aortic surgery. Methods: One hundred twenty patients were randomized to placement of PACs for perioperative monitoring and hemodynamic optimization (tune up) in the intensive care unit on the night before aortic operation, or to intravenous hydration in the ward and perioperative monitoring without PACs. Before randomization, all patients underwent routine adenosine thallium-201 scintigraphy. Results: To meet predetermined endpoints, 30 PAC patients (50%) received nitrates, inotropic agents, or both. PAC patients received more fluid in the preoperative period (p < 0.001) and in the first 24 hours after operation (p = 0.002) than control subjects. Eleven PAC patients (18%) and three control subjects (5%) had adverse intraoperative events (p = 0.02). There were 20 adverse postoperative events in 15 PAC patients (25%; nine cardiac, seven pulmonary, four acute tubular necrosis), which was not different compared with 11 postoperative events in 10 control subjects (17%; five cardiac, five pulmonary, one acute tubular necrosis). There were also no differences in duration of mechanical ventilation, intensive care unit stay, or hospital stay between groups. Postoperative cardiac complications were more common among patients who had a history of congestive heart failure (p = 0.02; odds ratio, 3.75; confidence interval, 1.3 to 11) or reperfusion defects on adenosine thallium scintigraphy (p = 0.01; odds ratio, 3.4; confidence interval, 1.2 to 9.4), regardless of group. Conclusions: Routine use of PACs for perioperative monitoring with the above protocol during aortic surgery is not beneficial and may be associated with a higher rate of intraoperative complications. Preoperative tune up does not prevent postoperative cardiac, renal, and other complications. Variables such as cardiac risk factors and adenosine thallium scintigraphy may be more important predictors of cardiac events in patients who undergo aortic operations. (J Vasc Surg 1998;27:203-12.)

Purpose: Morbidly obese patients who sustained popliteal vascular injury after spontaneous knee dislocation (KD) were studied. Methods: Seven morbidly obese patients (body mass index [BMI] >35 kg/m^2 and >100 lb over ideal body weight) who sustained spontaneous KD while upright were reviewed. Results: Severe popliteal arterial injury accompanied all spontaneous KD. The mean age of patients was 34.1 +/- 6.7 years; the mean weight was 354 +/- 150 lb (range, 220-702 lb); and mean BMI was 53 +/- 21 kg/m^2 (range, 37-98.4). All had arterial avulsion and thrombosis. Three had concomitant venous injury. All underwent operative repair. Morbid obesity presented unique challenges to surgical management. Limited positioning, specialized operative tables, large incisions, deep exposure, special retraction, long operative times (mean, 537 +/- 134 minutes), and major blood loss (mean, 2.5 +/- 3 L) were standard. Five arterial injuries were repaired with interposition vein grafts, and 2 required tibial bypass. Venous repairs included thrombectomy and primary repair (n = 2) and interposition grafting (n = 1). Many complications were related to morbid obesity, including deep wound infection (n = 3), diabetic ketoacidosis (n = 2), and cor pulmonale from sleep apnea (n = 1). Despite patent grafts in all patients, 2 above-knee amputations were required for extensive neuromuscular loss. Conclusion: Morbid obesity is a specific risk factor for spontaneous KD and vascular injury. In addition, morbid obesity presents unique challenges to operative repair and predisposes patients to unusual major postoperative complications. (J Vasc Surg 1998;28:458-63.)

Background and Purpose: A major gastrointestinal complication (GIC) after aortic surgery may be disastrous, but these complications have received scant attention. This study was performed to determine the risk factors, associated events, and outcomes for patients with GIC. Methods: We performed a secondary analysis of a prospective study that examined 120 consecutive patients who underwent transperitoneal aortic revascularization for aneurysmal or occlusive disease. Results: The following 29 GICs developed in 25 patients (21%) within 30 days of aortic surgery: paralytic ileus that required replacement of nasogastric tubes (n = 12), upper gastrointestinal bleeding (n = 5), Clostridium difficile enterocolitis (n = 5), acute cholecystitis (n = 2), mechanical obstruction (n = 2), ascites (n = 2), and colon ischemia (n = 1). Seven patients required operations for GICs after aortic revascularization. A comparison of patients with and without GICs showed no differences in the prevalence of risk factors, presence of mesenteric artery stenoses, coexisting medical illnesses, antecedent gastrointestinal history, operative indication, preoperative fluid administration, or duration of operation. However, patients with GICs had more intraoperative complications (P = .004), greater intraoperative blood loss (P = .02), and more fluids during the postoperative period (P = .008). The mean duration of mechanical ventilation was 71 +/- 23 hours for patients with GICs versus 7 +/- 2 hours for patients without GICs (P = .006). A higher prevalence of pulmonary (P = .004) and renal (P = .001) complications was seen in the patients with GICs. The mean stay in the intensive care unit was 16 +/- 2 days for patients with GICs as compared with 5 +/- 0.4 days for patients without GICs (P < .001). Four deaths occurred, all caused by multisystem organ failure: 3 patients had GICs, and 1 did not have a GIC (P = .007). Conclusions: These results show that GICs are prevalent in transperitoneal aortic surgery and are associated with severe morbidity rates, increased hospital costs because of prolonged stay, and increased mortality rates. Some GICs appear to be associated with intraoperative events that lead to visceral hypoperfusion, and others can be attributed to mechanical causes. However, none of the variables examined in this study were predictive of GICs. In all, GICs should be considered serious adverse sequela after aortic revascularization. Because no risk factors for GICs have been identified, these complications currently cannot be prevented. (J Vasc Surg 1998;28:404-12.)