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Background Renal dysfunction is a well-described complication of open juxtarenal abdominal aortic aneurysm repair, but the associated risk factors and corresponding impact on survival are not well described. Methods We identified all patients not on hemodialysis undergoing open repair of nonruptured juxtarenal aneurysms in the Vascular Quality Initiative from 2003 to 2017. We used mixed-effects logistic regression to determine factors associated with in-hospital postoperative renal dysfunction, including acute kidney injury (AKI, defined as serum creatinine concentration increase >0.5 mg/dL) and new renal replacement therapy (RRT), as well as the association between postoperative renal function and perioperative mortality. Cox regression was used to determine the association between postoperative renal complications and long-term survival. Results We identified 2635 open juxtarenal repairs, of which 621 (24%) were complicated by AKI. The majority of these (20% of the overall cohort) were AKI alone, but 2.2% required temporary RRT and an additional 1.7% were permanently dialysis dependent. Factors independently associated with postoperative renal dysfunction included renal-visceral ischemia time (per minute: odds ratio [OR], 1.01 [1.01-1.02]; P 25 minutes, but risk increased stepwise thereafter (25-39 minutes: OR, 1.6 [1.2-2.1; P = .004]; 40+ minutes: OR, 2.6 [1.9-3.5; P Conclusions Postoperative renal dysfunction, even a mild elevation in creatinine concentration, is associated with higher perioperative and long-term mortality. Although the routine use of mannitol and cold renal perfusion was not associated with postoperative renal dysfunction after open juxtarenal repair, cold renal perfusion was associated with lower risk of AKI if clamp times exceeded 25 minutes.

ObjectivesThe objectives of this study were to examine factors predictive of success or failure after percutaneous angioplasty (PTA) and stenting (S) of the superficial femoral artery (SFA) and to compare the results of PTA/S with a contemporary group of patients treated with femoropopliteal bypass.MethodsA database of patients undergoing PTA and/or S of the SFA between 1986 and 2004 was maintained. Intention-to-treat analysis was performed. Patients underwent duplex scanning follow-up at 1, 3, and every 6 months after the intervention. Angiograms were reviewed in all cases to assess lesion characteristics and preprocedure and postprocedure runoff. Results were standardized to current TransAtlantic Inter-Society Consensus (TASC) and Society for Vascular Surgery (SVS) criteria. Kaplan-Meier survival analyses were performed to assess time-dependent outcomes. Cox proportional hazard analyses were performed to assess factors associated with patient survival and treatment efficacy.ResultsThree hundred eighty total limbs underwent PTA/S in 329 patients (67% male, 33% female; average age, 65 years). Mean follow-up was 1.8 years from the date of initial intervention. Indications for intervention were claudication in 66%, rest pain in 16%, and tissue loss in 18%. Runoff at the tibial level was 2.1 ± 0.8 patent vessels. Mean SVS ischemia grade was 3.1 (range, 1 to 5). TASC lesion grades were A (48%), B (18%), C (22%), and D (12%). Angioplasty alone was used in 63% of cases. Primary treatment failure (inability to cross lesion) was seen in 7% of patients. There was one periprocedural death. Primary patency rates were 86% at 3 months, 80% at 6 months, 75% at 12 months, 66% at 24 months, 60% at 36 months, 58% at 48 months, and 52% at 60 months. Assisted primary patency rates were slightly higher (P = not significant). By Cox proportional hazards analysis, patency of PTA/S was associated with higher preoperative ankle/brachial index (P = .016) and the performance of angioplasty only (P = .011). Failed or occluded PTA/S was associated with TASC C (P < .0001) and TASC D lesions (P < .0001). Patient death was associated with the presence of congestive heart failure (P = .003). Subgroup analysis revealed that primary patency rates are highly dependent on lesion type (A > B > C > D, P < .0001). PTA/S patency for TASC A and B lesions compared favorably to prosthetic and venous femoropopliteal bypass. Surgical bypass was superior to PTA/S for TASC C and D lesions.ConclusionsPTA and stenting of the SFA can be performed safely with excellent procedural success rates. Improved patency of these interventions was seen with increased ankle/brachial index and the performance of angioplasty only. Worse patency was seen with TASC C and TASC D lesions. Patency rates were strongly dependent on lesion type, and the results of angioplasty and stenting compared favorably with surgical bypass for TASC A and B lesions.

ObjectivesThe purpose of this study was to determine whether performance on a simulator model of carotid artery stenting correlates with previous endovascular experience and to assess the effects of repetition and training.MethodsParticipants were stratified to untrained and advanced skill groups on the basis of number of endovascular procedures previously performed. Baseline performance was assessed by means of a pretest, and participants were randomized to practice and no-practice groups. Practice consisted of a 30-minute to 60-minute proctored session before taking a final test; those in the no-practice group proceeded directly to the final test without this session. Primary outcomes were completion of a standardized protocol and the length of time needed to complete all steps.ResultsTwenty-nine subjects (16 untrained, 13 advanced) participated fully in the study. Ninety-two percent of participants in the advanced group successfully completed the pretest, versus 63% in the untrained group (P = .09); mean time to successful completion was 29.9 ± 4.8 (mean ± SD) versus 48.0 ± 9.9 minutes, respectively (P < .001). Subjects who received no practice did not significantly improve their completion times between pretest and final test, whereas those who received practice did (novice, 47.9 ± 7.0 minutes vs 24.5 ± 2.9 minutes, P < .001; advanced, 29.6 ± 3.1 minutes vs 20.2 ± 4.1 minutes, P < .001). The group without previous training had significantly more time improvement from training than did the advanced group. Exit survey results showed that those who had the opportunity to practice more commonly believed that the simulator increased their endovascular skills and interest in vascular surgery (both P < .01 vs untrained group).ConclusionsPerformance on the carotid stenting simulator correlated with previous endovascular experience. Although both novice and advanced groups improved their time after a 30-minute to 60-minute proctored training session, improvement in the novice group was greater than that in the advanced group, which suggests that novices may benefit disproportionately from this type of training.

Objectives This study was performed to determine whether there is deterioration in renal function during follow-up in patients who have undergone endovascular aneurysm repair (EVAR), as recommended by the device manufacturers; to determine whether suprarenal fixation correlates with impairment of renal function; and to explore the potential implication of life-long surveillance of renal function with contrast-enhanced computed tomography. Methods One hundred forty-six consecutive patients underwent EVAR at our institution. Data from 113 of these patients who were free from preoperative renal insufficiency or postoperative renal disease were analyzed. Fifty-three patients received infrarenal (IR) fixation devices, and 60 patients received suprarenal (SR) fixation devices. All SR fixation devices were placed under investigational device exemption protocols. The average follow-up was 688 days. Sixty-five consecutive patients who had undergone open repair of an abdominal aortic aneurysm (AAA) served as the control group. Results Preoperative creatinine concentration, intraoperative blood loss, contrast volume, and number of contrast-enhanced procedures were not significantly different between the IR and SR groups. Two renal artery occlusions (1 SR, 1 IR; P = NS) were identified, and 8 renal infarcts (5 SR, 3 IR; P = NS). There was an increase in mean creatinine concentration in the open AAA, IR, and SR fixation groups at each time point in the analysis. Mean elevation in creatinine concentration at 12, 24, and 36 months was 0.10, 0.10, and 0.04 mg/dL, respectively, for open AAA repair; 0.20, 0.21, and 0.28 mg/dL for IR fixation; and 0.15, 0.21, and 0.12 mg/dL for SR fixation. At life table analysis, renal impairment at 36 months was seen in 36% ± 9% of patients in the IR group, 25% ± % of patients in the SR group, and 19% ± 6% of patients in the open AAA group ( P = .04 for IR fixation vs open AAA repair). Conclusions A decrease in kidney function is seen after EVAR, regardless of fixation level, that is independent of renal disease and renal arterial occlusion. In patients with normal renal function the site of proximal fixation does not affect postoperative creatinine concentration. The decrease in renal function is likely related to the repetitive administration of contrast agent.

Objectives Treatment of abdominal aortic aneurysm is controversial in patients at high physiologic risk for open repair and high anatomic risk for endovascular repair. We compared outcome in patients at high risk because of anatomy (short or angulated neck), severe occlusive disease, or bilateral iliac aneurysms (group A) with outcome in patients at low risk (group B). Material and methods Patients at high anatomic risk who underwent treatment between October 1998 and March 2002 with the Zenith endovascular graft (group A) were compared with patients at low anatomic risk enrolled in a prospective multicenter trial (group B). Variables compared included overall mortality, need for secondary interventions, development of endoleak, and change in aneurysm sac diameter. The χ 2 test, Student t test, and proportions analysis were used to assess the data. Results Data for 493 patients (group A, 141; group B, 352) were evaluated. Mean follow-up was 9 months (range, 1-24 months). Perioperative mortality was similar for groups A and B (0.7% vs 1%). Frequency of endoleak was higher in patients with high-risk anatomy (25% vs 11%), but not significantly so ( P > .06). The rate of aneurysm shrinkage, even in the absence of endoleak, was slower in group A ( P Conclusions In physiologically challenged patients at higher anatomic risk for endovascular aneurysm repair, initial mortality rate is similar to that in patients at lower risk. Short-term technical results are acceptable. Decreased long-term survival (largely unrelated to the procedure), slightly higher frequency of endoleak, and a lower rate of sac shrinkage may temper enthusiasm for endovascular repair in this subgroup. Risks of repairing aneurysms in this patient population must be viewed in the context of expected results of intervention or medical observation.

Purpose: To compare outcome after carotid endarterectomy (CEA) in patients who would have been excluded from the North American Symptomatic Carotid Endarterectomy Trial (NASCET) or the Asymptomatic Carotid Atherosclerosis Study (ACAS) or would have been eligible for Acculink for Revascularization of Carotids in High Risk Patients (ARCHeR), a current high-risk stent registry, with outcome in a similar cohort at low risk. Methods: Records of all CEAs performed at our institution from July 1993 to December 2000 were reviewed. Patients were assigned to groups either eligible or ineligible for NASCET and ACAS or ARCHeR, and criteria were stratified according to whether risk was defined by anatomic or medical problems or whether patients were ineligible according to nonmedical protocol exclusion criteria only. Results: Preoperative and postoperative data were sufficient to determine risk status according to various study criteria in 857 patients. Stroke or death within 30 days, the primary end point, occurred in 2.1% of patients. Rates were similar in patients excluded from (2.7%) or included in (1.6%) NASCET and ACAS and in patients eligible (3.1%) or ineligible (2.1%) for ARCHeR. Rates did not differ according to whether exclusion or inclusion was based on anatomic risk, medical risk, or protocol exclusion, although trends favored worse outcome in the ARCHeR medical risk subgroup. A higher rate of minor complications was found in the elderly; however, stroke and death rates were similar according to age, gender, repeat procedure, or the presence of contralateral occlusion. Conclusions: No statistically or clinically significant differences were found in combined 30-day stroke or death rates after CEA in any group defined by previous surgical trials or current ongoing high-risk stent registry. While high-risk groups may exist, the premise that operative risk is higher in patients excluded from NASCET and ACAS or eligible for ARCHeR is not supported. (J Vasc Surg 2003;37:575-81.)

Introduction: The endovascular repair of abdominal aortic aneurysms has become increasingly common during the past decade. Despite aggressive attempts to treat endoleak and graft failure with endovascular salvage procedures, some grafts necessitate surgical removal. We reviewed our experience with late endograft explantation in an effort to identify technical maneuvers critical for success. Methods: Of 110 patients treated with aortic abdominal endografts at the University of Rochester Medical Center between August 1997 and June 2001, five (4.5%) needed late graft removal. Medical records, radiographic files, and case report forms were retrospectively reviewed. Results: One Talent (Medtronic AVE, Santa Rosa, Calif) and four Vanguard (Boston Scientific, Natick, Mass) grafts were removed at a mean of 32.7 months (range, 18 to 44 months) after implantation. One patient underwent conversion for rupture, three for endoleaks (one each with types I, II, and III), and one for stent separation from the graft material without endoleak or aneurysm expansion. Three cases were approached via the midline, one through a bilateral subcostal incision, and one through a retroperitoneal incision. Supraceliac aortic control was used in all patients. Removal of two of the Vanguard grafts necessitated extension of the aortotomy above the level of the renal orifices. One perioperative death occurred. The mean operative blood loss was 4700 mL (range, 1850 to 9000 mL), and length of stay was 19.8 days (range, 7 to 42 days). Conclusion: The morbidity and mortality rates associated with late removal of endografts are significant. Removal of Vanguard devices can necessitate extension of the aortotomy above the renal arteries. We believe that control of the aorta well above the proximal fixation site is the key to removal and that continuous aortic exposure via retroperitoneal exposure is the best option in this situation. (J Vasc Surg 2002;36:674-8.)

Purpose: Analysis endpoints of patient survival and aortic rupture at a reporting interval of 12 months are regularly used to compare endograft aortic aneurysm (EAG) repair to conventional open surgical (COS) repair. This study reports a multicenter EAG repair versus COS repair parallel cohort trial at 12 months and additional observations of specific device failure types and their impact on an aortic endograft design beyond that follow-up period. Methods: From August 1997 to September 1998, 240 patients who were treated with bifurcation EAG repairs and 28 patients who were treated with straight EAG repairs were compared with 98 patients who were treated with COS repair for elective infrarenal aortic aneurysm repair. Allocation to treatment was based on aneurysm anatomy. All cohorts underwent infrarenal procedures. Data from concurrent, nonrandomized patient accrual from 17 United States institutions were prospectively gathered and independently adjudicated for safety and efficacy. An independent core laboratory evaluated all imaging data. Results: There were 308 men and 58 women (mean age, 72 years; range, 42-94 years) treated for infrarenal aortic aneurysm (mean diameter, 55 mm; range, 40-115 mm). Mean preoperative aneurysm diameters were clinically similar (EAG repair, 54 mm vs COS repair, 57 mm). The two cohorts were not significantly different in terms of gender ( P = .30) or age ( P = .32). EAG repair technical success (aneurysm exclusion, graft patency, patient survival) at 30 days was 89.2%. Five patients required immediate conversion to COS repair, four caused by access complications and one caused by operator-induced EAG repair malposition. The 30-day mortality rate was 1.5% for EAG repair and 3.1% for COS repair ( P = .59). The 12-month survival rate was 94.3% for EAG repair and 95.9% for COS repair. The intermediate-term cumulative survival rate at 24 months was 84.9% for EAG repair and 80.3% for COS repair ( P = .48). EAG repair device failure occurred from fabric erosion in six patients, with two deaths from ruptured aneurysm at 18 and 28 months after endografting and four device failures resolved by secondary procedures. Five endograft limb dislocations were all resolved by secondary endovascular procedures. Major or minor endograft migration required secondary procedures in five patients, including conversion in two patients. Conclusion: The clinical outcome at 12 months demonstrated effective aneurysm treatment and comparable safety between EAG repair and COS repair by conventional endpoints. Ongoing follow-up beyond 12 months revealed device-related adverse events that required endograft design changes. Diligent surveillance of outcomes beyond 12 months is necessary to adequately evaluate EAG repair devices. (J Vasc Surg 2001;33:S55-63.)

Purpose: To evaluate the initial and mid-term results of the Zenith endovascular grafting system for infrarenal abdominal aortic aneurysms. Methods: Prospective databases at seven centers were used to assess a cohort of patients that underwent treatment for aortic, aortoiliac, or iliac aneurysms since 1995. Data were analyzed to yield descriptive characteristics that pertained to the patients, the aortic morphologic features, the graft configuration, and the complications. Follow-up imaging data were used to determine size changes of the aneurysm sac, endoleak rates, and further complications. Finally survival data were expressed with a Kaplan-Meier analysis. Results: A total of 528 patients were treated with the Zenith endograft. Most of the patients (66%) were considered to be at a high physiologic risk for open repair. Successful graft implantation was accomplished in all but four patients. An overall endoleak rate of 15% was noted, of which 4% was treated urgently because they were thought to represent attachment site faults. The mean follow-up period was 18 months. A total of eight endograft migrations were detected after 2 years of follow-up with an early version of the system. There were three late conversions; two ruptures occurred during the follow-up period. Conclusion: This early and mid-term data support the use of the Zenith endovascular graft for the treatment of aortic and aortoiliac aneurysms in properly selected patients. The risks of significant complications or aneurysm rupture are low. (J Vasc Surg 2001;33:S157-64.)

Purpose: The purpose of this study was to examine the characteristics of residual and recurrent lesions after eversion endarterectomy of the carotid artery (E-CE) and compare these results with those following endarterectomy and patch closure (CE-P). Methods: We reviewed 274 patients who underwent carotid endarterectomy in 1998 with electroencephalographic monitoring, general anesthesia, completion duplex scan, and 1-year follow-up. CE-P was preferred for patients who required temporary shunting. In the E-CE group an additional proximal 2-cm arteriotomy was made in the common carotid artery (CCA) in 79 patients, a longer arteriotomy was made for extensive involvement of the CCA in 14 patients, and the internal carotid artery was advanced proximally as a patch for the CCA arteriotomy closure in 14 patients. Stenoses of > 50% that were present at 1 month were considered residual, and those of > 50% that were present at 1 year but not at 1 month were considered recurrent. Results: There were five (1.8%) postoperative strokes (four after CE-P and one after E-CE, P = not significant). At 30 days there were 28 patients (10.2%) with residual stenoses > 50% (11 patients [10.2%] in the E-CE group and 17 patients [10.1%] in the CE-P group; P = not significant). The incidence of recurrent lesions of more than 50% was similar (4.6% for E-CE vs 4.7% for CE-P). Conclusion: The pattern of residual lesions and recurrent stenoses differs with each technique of endarterectomy. Proximal stenoses are more common after E-CE, and distal stenoses are more common after CE-P at both 1 month and 1 year. The frequency of proximal lesions is reduced in E-CE when either the internal carotid artery is advanced proximally onto the CCA or a long CCA arteriotomy is made. Distal recurrences do not seem to be a problem after eversion endarterectomy. (J Vasc Surg 2000;32:1052-61.)

Objectives: The purpose of this study was to determine the long-term functional results after medial claviculectomy and venous patch angioplasty or bypass grafting using internal jugular vein after incomplete thrombolysis of effort thrombosis of the subclavian vein. Methods: The records of 11 patients with effort thrombosis who were treated over the past 9 years were reviewed. Patients have been followed up between 3 and 9 years at 6-month intervals with duplex imaging and contrast venography when indicated and have had an orthopedic evaluation of their shoulder function. Results: All reconstructed veins are patent, and only one patient complains of any arm swelling after prolonged usage. This patient is one of three with postphlebitic changes at the site of repair and has similar findings in her basilic vein. All patients have returned to their prethrombosis vocation without limitation. Four of the 11 patients have jobs requiring heavy physical labor. No patient describes any limitations of shoulder function, but one man who works as a diesel mechanic complains of shoulder aching with overuse with repetitive pulling. Three patients describe upper extremity paresthesias when lying on the operated side. Two patients (one man and one woman) are bothered by the large scar and indentation at the site of the incision. Every patient considers the overall result completely successful from a functional standpoint. Conclusions: Early subclavian venous repair performed through a medial claviculectomy is a durable operation with excellent long-term functional results. Half of the patients noted minor but significant symptoms, but all are uniformly able to return to normal function. (J Vasc Surg 2000;32:315-21.)

Background: The diagnosis, treatment, and long-term sequelae of lower extremity deep venous thrombosis (DVT) depend on the anatomic location and extent of the process, yet a lack of such fundamental knowledge has limited the development of effective protocols for managing patients with DVT. Methods: Venograms with evidence of acute DVT were evaluated, and the extent of the thrombotic process was recorded and correlated with the clinical presentation. Thrombi were classified according to the venous segments involved and to the thrombus' isolation to one segment or multiple segments. The left-to-right ratio of the DVT was assessed for various etiologic subgroups. Results: Among 2762 venograms performed in 2541 patients over a 10-year period, there were 885 cases (34.8%) of DVT documented. Of these cases, 344 cases (39%) were idiopathic, 307 cases (35%) were postoperative, 84 cases (10%) occurred in the setting of malignancy, and 70 cases (8%) occurred as the result of trauma. Distal thrombi were more common than proximal thrombi, with calf involvement in 734 patients (83%), femoropopliteal involvement in 470 patients (53%), and iliac involvement in 75 patients (9%). The most common site of thrombus was the peroneal vein, which was involved in 595 patients (67%). The ratio of left-to-right–sided DVT was 1.32:1 overall but was greater for proximal thrombi, with a ratio of 2.4:1 for iliac DVT versus 1.3:1 for infrainguinal DVT. The preponderance of left-sided DVT appeared to be related to the high-frequency, left common iliac vein involvement; the left-to-right ratio was much closer to equality (1.09:1) for isolated infrainguinal DVT. The anatomic configuration of the DVT was correlated with the etiologic subgroup; postoperative DVTs were more often distal, whereas DVT developing in the setting of malignancy was more frequently proximal and often right sided. Proximal, left-sided DVTs were common in the idiopathic subgroup, presumably as a result of undiagnosed left iliac vein webs. Conclusions: The frequency of distal vein involvement greatly exceeds that of proximal involvement in patients with DVTs. Proximal DVTs are more frequently left sided, whereas distal DVTs occur with a more equal left-to-right distribution. The anatomic extent of DVTs appears to depend on the etiology of the process. These observations may shed light on the pathophysiology of venous thrombosis. The findings are of value in planning therapeutic interventions directed at venous recanalization. (J Vasc Surg 2000;31:895-900.)

Purpose : This trial was designed to identify factors affecting patency rates of primary prosthetic above-knee femoropopliteal bypass grafts at 5 years. Methods : A multi-institutional, prospective trial randomized 240 patients to compare patency rates of Gore-tex and Hemashield above-knee femoropopliteal bypass grafts at 5 years. Univariate comparisons of patency between levels of each prognostic variable were made with the Kaplan-Meier method. Variables that had a univariate P value less than.25 or those known to be important were submitted to a Cox regression analysis. Results : The patient survival rate at 5 years was 59.4%. There were no differences in primary or secondary patency rates at 5 years between the two graft materials (primary, 45% vs 43% and secondary, 68% vs 68%). The risk for graft occlusion was significantly increased for patients younger than 65 years (2.1; P =.001) and for grafts with a diameter less than 7 mm (1.65; P =.0219). Variables with no apparent independent effect on patency rates were smoking status, runoff, diabetes mellitus, sex, presenting symptoms, and postoperative treatment with aspirin or Coumadin. Noninvasive test results were not predictive of subsequent graft function. Conclusion : Although the type of prosthetic used for above-knee femoropopliteal bypass grafts does not affect 5-year patency rates, age and graft size do influence results. These factors should be considered before a prosthetic bypass grafting procedure. Furthermore, these data should serve as a contemporary standard, with which evolving and conventional procedures can be compared. (J Vasc Surg 2000;31:417-25.)

Objective: Subfascial endoscopic perforator surgery (SEPS) results in acceptable healing and recurrence rates. The role of hemodynamic venous testing in this situation, however, is poorly understood and inconsistently used. Our ongoing experience was reviewed to explore how SEPS affects the photoplethysmographic assessment of the leg. Methods: Preoperative and postoperative venous refill times (VRTs) were measured with photoplethysmography in 30 limbs in 28 patients who underwent SEPS and superficial ablation, when indicated, with complete clearing of the anterolateral surface of the tibia, thus opening the deep posterior compartment from mid calf to close to the malleolus. Postoperative healing and duplex scanning were used to assess clinical and anatomic success, respectively. The VRTs were classified as “interpretable” if the leg emptied or “uninterpretable” if the calf could not empty. The “interpretable” study results were further classified as “normal” if the refill took 20 seconds or more or “abnormal” if less. Results: Before the patients underwent SEPS, six study results (20%) showed inability of the calf to empty and thus were judged uninterpretable. After the patients underwent SEPS, 12 study results (40%) were uninterpretable (NS; P = .09 with the χ2 test). Of the 24 preoperative interpretable study results, two (8%) were normal, and of the 18 postoperative interpretable study results, seven (39%) were normal (P < .03). With the consideration of only interpretable study results, the mean VRT increased slightly from 12.0 ± 5.1 seconds (mean ± standard deviation) to 14.3 ± 8.1 seconds (NS). Seventeen of 19 ulcers (89%) had healed at a mean follow-up period of 8.6 ± 4.8 months. Conclusion: Although VRT is unpredictably affected by SEPS, the most consistent finding is the inability of the calf to empty, which invalidates the remainder of the test. In addition, most ulcers heal, even with uninterpretable or abnormal postoperative VRTs. This suggests that photoplethysmography is a poor method of assessment of venous reflux after SEPS. (J Vasc Surg 1999;30:1067-76.)

Purpose: The evaluation of treatment strategies for deep venous thrombosis (DVT) is assessed through the use of a reliable method of quantifying the extent of the thrombotic process. Previous indices of thrombus burden have suffered from various limitations, including lack of clinical relevance, poor correlation with actual thrombus mass, and failure to include important venous segments in the methodology. The use of a novel scheme of quantifying venous thrombus was evaluated as an alternative method that would avoid some of the drawbacks of existing indices. Methods: The volumes of 14 venous segments (infrarenal inferior vena cava, common iliac, hypogastric, external iliac, common femoral, profunda, superficial femoral, and popliteal and six tibial veins) were calculated from computed tomography (pelvic vein diameter), duplex ultrasound scan (infrainguinal vein diameter), and contrast venography (length of all segments) measurements. A venous volumetric index (VVI) was assigned with the normalization of the values to the volume of a single calf vein. The VVI was validated with the assessment of the ability to discriminate between asymptomatic and symptomatic DVT and between those DVT that were associated with pulmonary emboli and those that were not. Results: With the imaging data, the VVI ranged from 1 for a single calf vein thrombus to 26 for the infrarenal inferior vena cava. Each VVI unit represented 2.3 mL of thrombus, with a maximum possible score of 63 representing a thrombus burden of 145 mL for a single extremity, including the infrarenal inferior vena cava. In 885 patients with DVT, the VVI ranged from 1 to 56, averaging 3.9 ± 0.2 in patients who were asymptomatic and 8.7 ± 0.3 in patients who were symptomatic (P < .001). The VVI was similar in the patients with pulmonary emboli as compared with those without (9.6 ± 1.2 vs 7.7 ± 0.2, respectively). In comparison with the three existing methods of quantifying venous thrombus burden, the receiver operating characteristic curve analysis results suggested that the VVI and the Venous Registry index were better than the other two indices in the discrimination of patients with symptomatic and asymptomatic DVT (P < .001). Conclusion: A novel index of venous thrombus burden, on the basis of actual venous volume measurements, was more accurate than present indices in the differentiation between clinical categories of patients with DVT. As such, it offers an acceptable alternative to current scoring systems. (J Vasc Surg 1999;30:1060-6.)

J Vasc Surg 1998; 28:955-63.

Popliteal artery aneurysms rarely rupture. We treated a 91-year-old man who presented with a deep venous thrombosis and anemia; rupture of a popliteal artery aneurysm was suspected only after compartment syndrome isolated to the thigh developed as the result of bleeding. Although fasciotomy was required on the basis of the clinical examination alone, the cause of the problem, operative strategy, and definitive treatment (i.e., resection and bypass) were clarified by the preoperative computed tomography scan. Ruptured popliteal aneurysm can manifest as a massively swollen leg with anemia and should be suspected if no other cause is evident. (J Vasc Surg 1998;27:783-7.)

Purpose: An increased incidence of bleeding complications has been observed after supraceliac aortic clamping (SCC). This study was performed to identify possible hemostatic abnormalities that contribute to this problem.Methods: A prospective cohort study over a 3-month period was performed by comparing hemostatic parameters in 10 consecutive patients who required elective SCC with those of eight concurrent randomly selected control subjects who required infrarenal clamping (IRC) for abdominal aortic reconstruction. Measures of coagulation, fibrinolysis, platelet function, temperature, hemodilution, and hepatic function were performed at selected times before, during, and after operation.Results: Aneurysm size, fibrinogen, D-dimers, prothrombin, partial thromboplastin time, platelet counts, bleeding times, hemodilution, and temperature were comparable in both groups. Patients in the SCC group, however, consistently developed a primary fibrinolytic state within 20 minutes after supraceliac clamping, reflected by significantly decreased euglobulin clot lysis times (ECLT; p < 0.0001), elevated tissue plasminogen activator (t-PA) levels ( p < 0.0006), elevated t-PA–to–plasminogen activator inhibitor-1 ratios ( p < 0.0001), and reduced α2-antiplasmin levels ( p < 0.002). SCC produced hepatocellular injury documented by elevations in both aspartate transaminase ( p < 0.0001) and lactate dehydrogenase ( p < 0.009).Conclusions SCC rapidly induces a primary fibrinolytic state manifested by increased circulating t-PA, reduced α2-antiplasmin, and increased fibrinolytic activator–to–inhibitor ratios. These effects may be a result of hepatic hypoperfusion caused by SCC leading to insufficient clearance of t-PA. Antifibrinolytic agents may be of benefit if bleeding develops after aortic procedures that require supraceliac clamping. (J Vasc Surg 1997;25:244-54.)

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 (

Purpose: Activated protein C (APC) is a naturally occurring anticoagulant that interacts with factors V and VIII to inhibit the clotting cascade. Resistance to APC (APC-R), hypothesized to occur as a result of an abnormal factor V, has been documented in up to 40% of patients with venous thrombotic events, but its prevalence in patients with arterial disease remains ill defined. Methods: With an assay of APC resistance that expresses the ratio of the activated partial thromboplastin time with and without the addition of exogenous APC, APC resistance ratios were quantitated in 200 individuals comprising 177 patients with vascular disease and 23 control subjects. An abnormal activated partial thromboplastin time was present in four patients who were excluded from analysis. The 173 remaining patients formed the study population and were divided into diagnostic subgroups on the basis of the most symptomatic problem. Results: APC resistance was documented in 20 individuals, representing 11.6% of the study group. The highest prevalence of APC resistance was observed in patients with lower extremity occlusive disease, with the APC-R ratio below 2.0 in 13.%. Within the subgroup of individuals with lower extremity disease, 76 patients (10 with APC-R, 13.2%) underwent infrainguinal bypass and were monitored a mean of 47±8 months. Occlusion of the arterial reconstruction occurred in 22 patients (29%). Six (60%) of the patients with APC-R had failed reconstructions, versus 16 (24%) of 66 patients without APC-R (p=0.02). Conclusions: These findings suggest that APC-R is relatively common in patients with peripheral vascular disease, especially in those with lower extremity occlusive disease. APC-R appears to be a risk factor for failure of infrainguinal bypass. These observations suggest that screening for APC-R may be useful in patients with peripheral vascular disease, providing the opportunity to restore the normal thrombogenic balance with anticoagulant therapy in susceptible individuals.

Purpose: A variety of preoperative provocative tests have been used to define the risk of cardiac morbidity and mortality after peripheral vascular procedures, including dipyridamole myocardial scintigraphy and dobutamine stress echocardiography. Although highly sensitive, these tests are time-consuming and associated with significant expense. We investigated outpatient echocardiography as a less resource-intensive means of assessing cardiac risk with operation. Methods: Over a 2-year period 250 consecutive patients underwent outpatient transthoracic echocardiography before elective peripheral vascular operation was performed. The accuracy of the Goldman, Detsky, and the American Society of Anesthesiologists' Physical Status Classification clinical indexes of cardiac risk were assessed with regard to the development of cardiac complications such as unstable angina, myocardial infarction, life-threatening ventricular arrhythmias, severe congestive heart failure, and cardiogenic shock. The accuracy of echocardiographically determined left ventricular ejection fraction was determined at threshold values between 20% and 60%. Results: Perioperative cardiac events developed in 23 (9.2%) of the patients, and nine (3.6%) of the patients died as a result of these complications. Clinical indexes lacked sensitivity in the preoperative prediction of cardiac complications. Receiver operating curve analysis defined a left ventricular ejection fraction of less than 50% as an appropriate threshold for defining patients at high risk, with a sensitivity of 78% and a specificity of 81% in the identification of patients who had cardiac morbidity. The positive predictive value was 27%, and the negative predictive value was 97%. The economic impact of outpatient echocardiography was well below that of dipyridamole myocardial scintigraphy or dobutamine stress echocardiography. Conclusions: Outpatient echocardiography appears to offer a cost-efficient compromise between clinical criteria alone and provocative cardiac testing such as dipyridamole myocardial scintigraphy and dobutamine stress echocardiography in the preoperative screening of patients undergoing peripheral vascular surgical procedures. (J VASC SURG 1995;22:671-9.)

Purpose: We sought to determine whether low-dose radiation can inhibit neointimal hyperplasia immediately after balloon injury to the common carotid artery and to assess the extent of endothelial regeneration after treatment.Methods: Sprague-Dawley rats were subjected to balloon injury to the common carotid artery. Immediately after injury rats were treated with a single dose of iridium 192 radiation at 5 gy, 10 gy, and 15 gy or received no radiation (control). Three weeks after injury and treatment, vessels were harvested and compartment areas were measured on fixed specimens. Scanning and transmission electron microscopy, along with Evans blue dye uptake into injured vessels, was used to assess the effect radiation had on endothelial regeneration.Results: Rats receiving radiation at all three doses demonstrated no intimal thickening when compared with rats that were not treated (at 5 Gy 0.01 ± 0.01 mm2; at 10 Gy 0.02 ± 0.01 mm2; at 15 Gy 0.05 ± 0.02 mm2; with balloon injury/no radiation 0.12 ± 0.02 mm2; p < 0.01). In addition, the groups that were irradiated had no medial thickening when compared with control rats (at 5 Gy 0.22 ± 0.02 mm2; at 10 Gy 0.21 ± 0.02 mm2; at 15 Gy 0.22 ± 0.07 mm2; with balloon injury/no radiation 0.37 ± 0.03 mm2; p < 0.01). Endothelial regeneration, evaluated by transmission and scanning electron micrographs along with uptake of Evans blue dye, was significantly greater in animals that received radiation compared with controls.Conclusions: Low-dose radiation prevents the occurrence of neointimal hyperplasia after balloon injury and may have a future role in vascular grafting. (J Vasc Surg 1995;22:17-24.)

The structure of infrarenal aortic aneurysm was studied as a basis for design of a transfemoral system of aneurysm repair. This information was particularly important because endovascular techniques, unlike conventional techniques, afford little opportunity for intraoperative adjustments.Three-dimensional computer reconstructions of the distal aorta, the renal arteries, the aneurysm and the iliac arteries were generated from computed tomography scanning data in 22 patients with aortic aneurysms.The proximal neck of the aneurysm was longer than 20 mm in 14 patients, and the mean length (of all 22) was 26.7 +/- 4.1 mm. In contrast, only one patient had a distal cuff longer than 20 mm and 14 of the others had no measurable distal cuff. The mean distal cuff length (of all 22) was 4.2 +/- 1.6 mm. There was no significant difference between mean aneurysm diameter in the anteroposterior direction (58.0 +/- 3.2 mm) and the transverse direction (56.4 +/- 3.3 mm), although corresponding values in individual patients were often different. Aneurysm diameter correlated with aneurysm length (r = 0.79, p0.001). The proximal right common iliac artery deviated from the axis of the distal aorta by 40.0 +/- 5.8 degrees, whereas the left deviated by 47.8 +/- 5.4 degrees. One of the iliac arteries deviated by more than 45 degrees in 12 cases. Eleven common iliac arteries in seven patients were aneurysmal. Fifteen patients had no aneurysm of the common iliac arteries, and another three had segments of nondilated common iliac artery distal to iliac aneurysms on both sides.Computerized three-dimensional reconstruction facilitated interpretation of anatomic information from computed tomography scans, particularly the length of the aneurysm neck and shape of the iliac arteries. On the basis of this information, we expect that few patients will have too short an aneurysm neck for endovascular aneurysm repair, but many will require a bifurcated graft for secure, hemostatic implantation distally.

Purpose: Despite the widespread use of intraarterial thrombolytic therapy for peripheral arterial occlusive disease, a randomized study comparing its efficacy with that of operative intervention has never been performed. This study evaluates the potential of intraarterial urokinase infusion to provide clinical benefits in patients with acute peripheral arterial occlusion. Methods: Patients with limb-threatening ischemia of less than 7 days' duration were randomly assigned to intraarterial catheter-directed urokinase therapy or operative intervention. Anatomic lesions unmasked by thrombolysis were treated with balloon dilation or operation. The primary end points of the study were limb salvage and survival. Results: A total of 57 patients were randomized to the thrombolytic therapy group, and 57 patients were randomized to the operative therapy group. Thrombolytic therapy resulted in dissolution of the occluding thrombus in 40 (70%) patients. Although the cumulative limb salvage rate was similar in the two treatment groups (82% at 12 months), the cumulative survival rate was significantly improved in patients randomized to the thrombolysis group (84% vs 58% at 12 months, p = 0.01). The mortality differences seemed to be primarily attributable to an increased frequency of in-hospital cardiopulmonary complications in the operative treatment group (49% vs 16%, p = 0.001). The benefits of thrombolysis were achieved without significant differences in the duration of hospitalization (median 11 days) and with only modest increases in hospital cost in the thrombolytic treatment arm (median $15,672 vs $12,253, p = 0.02). Conclusions: Intraarterial thrombolytic therapy was associated with a reduction in the incidence of in-hospital cardiopulmonary complications and a corresponding increase in patient survival rates. These benefits were achieved without an appreciable increase in the duration of hospitalization and with only modest increases in hospital cost, suggesting that thrombolytic therapy may offer a safe and effective alternative to operation in the initial treatment of patients diagnosed with acute limb-threatening peripheral arterial occlusion. (J VASC SURG 1994;19:1021–30.)

Purpose: Vascular reconstruction alone can be insufficient for extremity salvage in some patients with severe soft-tissue wounds. We present our experience in 20 patients with vascular reconstruction for ischemic disease and free-tissue transfer for limb-threatening soft-tissue wounds. Methods: Nineteen patients underwent autogenous venous bypasses and one patient underwent an aortobifemoral bypass. Ten soft-tissue reconstructions were performed at the time of the vascular reconstruction and 10 were delayed. Free-tissue transferred included muscle, fasciocutaneous flaps, and omentum. Inflow to the flap was from the bypass graft ( n = 12) or the distal tibial artery. Results: One free flap and graft failed immediately in the same patient. One successful flap and graft required a below-knee amputation for ongoing infection in the surrounding soft tissues. Eighteen of 20 patients have had free-flap and graft patency during the mean follow-up period of 17 months (range 6 to 33 months). These 18 patients ambulate independently. Conclusions: In patients with arterial insufficiency and severe soft-tissue wounds, combined vascular reconstruction and free-tissue transfer permits extended limb salvage with excellent functional results. (J VASC SURG 1993;18:972-80.)

Purpose: The purpose of this study was to develop an endovascular system for transfemoral placement of straight aortic grafts and bifurcated aortoiliac grafts. Methods: Both types of graft consist of barbed, self-expanding stents attached to a woven polyester fabric. Survival studies of straight-graft function were performed in six large mongrel dogs. Digital subtraction fluoroscopic equipment was used to guide insertion and record angiograms at 0, 1, and 3 months. Bifurcated grafts were inserted in an additional eight dogs, four with distal stents and four without. Straight grafts were inserted into six cadaveric aortas (five atherosclerotic and one aneurysmal; age 68.7 + 5.7 years) to assess stent attachment. Results: Angiograms obtained immediately after straight-graft insertion showed placement to be within 4.6 + 1.6 mm of the intended level. Follow-up angiograms at 1 and 3 months showed no migration, no leakage, and patency of all six grafts. After bifurcated graft insertion there were no angiographic signs of perigraft leakage, with or without distal stents. The mean force required to displace straight grafts 10 mm from their original position in cadaveric aortas was 1388 + 127 g . Conclusion: These preliminary results show that straight and bifurcated endovascular grafts can be positioned accurately and securely in the abdominal aorta. (J VASC SURG 1993;18:185-97.)

The antiphospholipid syndrome was diagnosed in 19 of 1078 patients treated between 1987 and 1991. All patients with antiphospholipid syndrome had either anticardiolipin antibody (16/19) or lupus anticoagulant (10/19); three patients had thrombocytopenia, eight patients had a prolonged partial thromboplastin time, and 10 patients had an elevated erythrocyte sedimentation rate. The most common site of involvement was the cerebral circulation (nine patients), manifested by transient ischemic attacks or stroke. Eight patients had upper extremity disease, characterized by symptoms of Raynaud's phenomenon, with angiographic lesions involving the brachial, radial, ulnar, and/or digital arteries. Lower extremity disease occurred in seven patients, with clinical presentations similar to those of atherosclerosis and varying angiographic patterns. In comparison with the population having atherosclerosis, patients with arterial manifestations of antiphospholipid syndrome were more likely to be women (13 of 19 versus 411 of 1078, p less than 0.02), were significantly younger (46.2 years versus 63.6 years, p less than 0.0001), did not smoke (1 of 19 patients versus 700 of 1078, p less than 0.0001), had a higher percentage of upper extremity involvement (8 of 18 versus 13 of 1078, p less than 0.0001), and had a higher incidence of early graft failure (9 of 12 grafts versus 13 of 371 grafts, p less than 0.0001). The syndrome is associated with the repetitive failure of vascular reconstructions and occlusion of native vessels. Antiphospholipid syndrome should therefore be suspected in young, female, nonsmokers with vascular disease, especially those with involvement of the upper extremity, cerebrovascular disease with normal findings on extracranial carotid angiography, and premature graft failure.

The diameter of aortic aneurysms were standardized to measures of patient size and normal aortic size in an effort to define indexes that might be more predictive of aneurysm rupture than raw aneurysm diameter alone. Normal aortic diameters were measured in 100 patients undergoing abdominal CT scans for other reasons, and an average infrarenal aortic diameter of 2.10 ± 0.05 cm was observed. Normal aortic diameter was dependent on both age and sex, ranging from 1.71 ± 0.06 cm in women below age 40 years to 2.85 ± 0.04 cm in men above age 70 years. Overall, 11 (5.1%) of the ruptures occurred in aneurysms less than 5 cm in diameter, and four (1.9%) occurred in aneurysms less than 4.0 cm in diameter. When the CT scans of 100 patients undergoing elective aneurysm resection were compared with those of 36 patients with ruptured aneurysms, no threshold diameter value accurately discriminated between the two groups. However, standardization of the aneurysm diameter to the transverse diameter of the third lumbar vertebral body as an index of patient body size produced an accurate predictor of rupture when a threshold ratio of 1.0 was used. No aneurysm ruptured below this ratio, but 29% of elective aneurysms were smaller than the vertebral body diameter. Receiver operating characteristic curve analysis confirmed the superiority of the aneurysm to vertebral body diameter ratio as a discriminator of ruptured aneurysms. It appears that aneurysm diameter alone is not sufficiently predictive of rupture to be used as the sole indication for elective resection. ( J Vasc Surg 1992;15:12–20.)

We reviewed our 12-year experience with transaxillary first rib resection in 136 patients screened by neurologists and thought to have neurologic thoracic outlet syndrome to determine what factors affected outcome. These patients represented 85% of the operative experience in a referral area of 1.2 million people. Patients were recalled every 2 years for surveillance. The mean follow-up was 60 +/- 7 months. There were no brachial plexus or vascular injuries. Secondary operations in the neck were required in 20 patients. The quality of the operative result was determined by whether the patient was able to return to preillness activities and whether the patient would undergo operation again if the same result would be obtained. The most important determinant of result was a history of trauma precipitating the neurologic symptoms, particularly in women. Only 25 of the 53 patients (47%) with a history of trauma returned to preillness activities compared to 65 of the 83 patients (78%) without such a history. Overall patient satisfaction was not affected by trauma. Thirty-eight of the 53 patients with trauma (72%) and 69 of the 83 patients (83%) without trauma were satisfied. When the men and women were analyzed separately men were found to have better results after trauma than did women. Other factors with a negative impact on operative results were the need to return to an activity that required repetitive arm movements, coverage under a worker's compensation insurance policy, and fixed joint abnormalities or neurologic findings in the upper extremity. The presence of an anatomic abnormality had no effect on operative results.(ABSTRACT TRUNCATED AT 250 WORDS)

Most early reports on the efficacy of laser angioplasty have used subjective symptoms rather than objective hemodynamic parameters to evaluate clinical results. We reviewed our experience with hot tip laser-assisted balloon angioplasty in 99 occluded or stenotic arterial segments during 80 procedures in 71 patients, ranging from the aortic bifurcation to the tibial-peroneal trunk. Initial failure to successfully recanalize occluded or stenotic segments occurred in 13 instances (16%). Forty-one procedure-related complications occurred in 31 patients (39%). Functional results were evaluated by use of life-table methods on the basis of symptomatic versus hemodynamic improvement. Cumulative patency rates for symptomatic and hemodynamic improvement were 91% and 64% at 1 month, 71% and 48% at 6 months, and 57% and 34% at 1 year, respectively. These data suggest that symptomatic improvement alone gives a misleadingly high estimate of the efficacy of laser angioplasty when compared with more objective hemodynamic criteria (p less than 0.005). Hemodynamic success was more likely in aortoiliac lesions than femoropopliteal lesions (58% vs 18% at 1 year, p less than 0.01). Hemodynamic parameters should be used to evaluate the success of laser angioplasty, which in its present form, is associated with frequent complications and poor long-term success.

Over a 5-year period 642 patients underwent 686 carotid endarterectomies with patch closure and intraoperative surveillance with continuous-wave Doppler. The perioperative stroke rate was 1.5%. Patients were screened with duplex scans immediately after operation for the presence of residual carotid lesions, and followed every 3 to 6 months for either the development of a true recurrent lesion or a change in a residual one. Five hundred thirty-nine arteries (84%) had no postoperative abnormalities. The incidence of recurrent carotid lesions in this groups was 1.5%, 3.4%, and 5.2% at 1, 2, and 3 years, respectively. The incidence of symptoms in this group was 0.2%, 0.7%, and 1.4% at 1, 2, and 3 years, respectively. The earliest recurrence or symptom occurred 8 months from operation. One hundred forty-seven arteries had residual lesions that were more common when either a temporary shunt was used or the operation was carried out above the hypoglossal nerve or below the omohyoid muscle. Sixty-one patients who had plaque proximal to the arteriotomy without a significant stenosis were followed an average of 21 months. There were no changes in plaque morphology and no proven symptoms related to the residual lesion. Fifty-six patients with both plaque and significant hemodynamic abnormalities in the carotid bulb were followed an average of 18 months. Seven of these patients (12.5%) had either a significant deterioration of the lesion or a symptom from it. Each event occurred within 6 months of operation. Thirty patients had significant flow abnormalities but no visible plaque. None of these lesions deteriorated. Although common, residual carotid lesions are benign unless the lesion is characterized by both plaque within the artery and a hemodynamically significant stenosis. These lesions should be further investigated and treated when discovered. (J VASC SURG 1991;13:112-20.)

The 10-year experience of a single community was reviewed and a multivariate analysis was performed to determine the relative importance of clinical and environmental factors in mortality after ruptured abdominal aortic aneurysm resection. Ruptured aneurysms were repaired in 243 patients in six area hospitals (one university, five community) by 25 surgeons (16 vascular, 9 general). Overall, 30-day mortality was 55% (133/243). Although the mortality by hospital ranged from 44% to 68%, these differences were not statistically significant. However, significant variations occurred in the mortality rates of individual surgeons, ranging from 44% to 73%. The mortality rate for the vascular surgeons was less than that of the general surgeons, 51% versus 69% (p less than 0.05). Clinical factors were evaluated, and the most significant parameters were systolic blood pressure, presence of chronic obstructive lung disease, and history of chronic renal insufficiency. These results support the implication that the degree of specialization of the surgeon and the preexisting health of the patient are the most important determinants of survival after ruptured abdominal aortic aneurysm. The size and sophistication of the hospital appear to be less influential factors.

A canine model was developed to study the differential response of a gram-negative and a gram-positive bacterial infection on autogenous and prosthetic grafts. After replacing segments of the femoral arteries of 15 dogs with autogenous vein in one groin and polytetrafluoroethylene in the contralateral groin, 10(8) colony-forming units of nonmucin-producing Staphylococcus epidermidis (five dogs), Pseudomonas aeruginosa (five dogs), or sterile saline solution (five dogs) were directly inoculated onto the grafts. The grafts were examined 7 to 10 days after implantation. None of the control dogs exhibited inflammatory signs, and no grafts or anastomoses disrupted. S. epidermidis was unrecoverable from either graft material in any of the animals, although histologic evaluation confirmed neutrophils and bacteria in four of five animals in the vein and polytetrafluoroethylene groups. No dog inoculated with S. epidermidis had graft or anastomotic disruption. By contrast, P. aeruginosa was recovered from both types of grafts in all inoculated animals. Neutrophils, bacteria, and microabscesses were observed in all of these animals. In addition, three of five polytetrafluoroethylene grafts and all five vein grafts disrupted either at the anastomoses or in the body of the vein graft. Therefore S. epidermidis is a less virulent organism that may persist in graft walls despite negative cultures, whereas P. aeruginosa is a highly virulent organism that can disrupt native artery, vein grafts, and anastomoses. The graft material appears to be less important than the bacteria in determining the outcome of infection.

One hundred seventy-seven patients with infrainguinal bypass grafts were followed by use of standard graft surveillance techniques to learn more about the natural history of hemodynamic abnormalities in the patient with no symptoms. A decrease in the ankle/brachial pressure ratio of 10% or more was considered an abnormal evaluation. Results of the duplex scan were interpreted as abnormal when the peak systolic flow velocity was greater than 120 cm/sec or less than 40 cm/sec. There were 18 graft thromboses (10%) during the period of observation, and nine of these grafts were successfully revised or replaced. Recurrent symptoms prompted graft revision in 20 additional patients, and 18 of these reoperations were successful. Twenty-nine of the 38 reoperations occurred within the first 18 months of the study. The primary cumulative patency rate was 86% at 1 year and 66% at 5 years. The secondary cumulative patency rate was 91% at 1 year and 80% at 5 years. Sudden graft occlusion occurred in five patients after a normal ankle/brachial index. Most of 90 patients with abnormal ankle/brachial indexes reverted to normal at the next visit. Nineteen of the 26 that did not, had significant graft problems, but only eight patients had operable conditions, and five of the eight already had occluded grafts. No patient with a normal ankle/brachial index and duplex scan results had graft occlusion before their next surveillance visit. If the duplex scan outcome was abnormal but the ankle/branchial index normal the incidence of sudden graft occlusion was 4%. In contrast, if the duplex scan outcome was abnormal and the ankle/brachial index is reduced, then the risk of graft occlusion is 66%.(ABSTRACT TRUNCATED AT 250 WORDS)

A 25-year-old woman with anomalous circulation to the right leg was seen with a symptomatic aneurysm of the abnormal vessel. The artery, which did share some features of the classic persistent sciatic artery, also had important differences that were not previously described in the literature. The patient manifested several associated vascular and nonvascular congenital anomalies. She underwent resection of the aneurysm and primary operative repair of the artery without difficulty. An embryologic interpretation is offered, and the clinical implications and management strategy are discussed. (J Vasc Surg 1998;28:1112-4.)

ObjectivePercutaneous intervention for symptomatic renal artery atherosclerosis is rapidly replacing surgery in many centers. This study evaluated the anatomic and functional outcomes of endovascular therapy for atherosclerotic renal artery stenosis on a combined vascular surgery and interventional radiology service at an academic medical center.MethodsThis was a retrospective analysis of patients who underwent renal artery angioplasty with or without stenting between January 1990 and June 2002. Indications included hypertension (86%) and rising serum creatinine concentration (55%). One hundred forty-six patients (80 women; average age, 71 years [range, 44-89 years]) underwent 183 attempted interventions (64 to treat bilateral stenosis). Forty-five percent of patients had significant bilateral disease: 27% had greater than 50% bilateral stenosis, and the remainder had nonfunctioning, absent, or occluded vessels.ResultsOf 183 planned interventions, technical success (

Objectives We examined economic and practice trends after 5 years of a merger between vascular surgeons and interventional radiologists. Methods In 1998 a merger between the Division of Vascular Surgery and the Section of Interventional Radiology at the University of Rochester established the Center for Vascular Disease (CVD). Business activity was administered from the offices of the vascular surgeons. Results In 1998 the CVD included five vascular surgeons and three interventional radiologists, who generated a total income of $5,789,311 (34% from vascular surgeons, 24% from interventional radiologists, 42% from vascular laboratories). Vascular surgeon participation in endoluminal therapy was limited to repair of abdominal aortic aneurysms (AAAs). Income was derived from 1011 major vascular procedures, 10,510 catheter-based procedures in 3286 patients, and 1 inpatient and 3 outpatient vascular laboratory tests. In 2002 there were six vascular surgeons (five, full-time equivalent) and four interventional radiologists, and total income was $6,550,463 despite significant reductions in unit value reimbursement over the 5 years, a 4% reduction in the number of major vascular procedures, and a 13% reduction in income from vascular laboratories. In 2002 the number of endoluminal procedures increased to 16,026 in 7131 patients, and contributions to CVD income increased from 24% in 1998 to 31% in 2002. Three of the six vascular surgeons performed endoluminal procedures in 634 patients in 2002, compared with none in 1998. Conclusions Gross revenues increased in a declining reimbursement and conventional practice environment, because of the increased number of endoluminal procedures, in part provided by vascular surgeons. The implications of these data should be considered by those responsible for training vascular surgeons.

The endovascular repair of abdominal aortic aneurysms has become increasingly common during the past decade. Despite aggressive attempts to treat endoleak and graft failure with endovascular salvage procedures, some grafts necessitate surgical removal. We reviewed our experience with late endograft explantation in an effort to identify technical maneuvers critical for success.Of 110 patients treated with aortic abdominal endografts at the University of Rochester Medical Center between August 1997 and June 2001, five (4.5%) needed late graft removal. Medical records, radiographic files, and case report forms were retrospectively reviewed.One Talent (Medtronic AVE, Santa Rosa, Calif) and four Vanguard (Boston Scientific, Natick, Mass) grafts were removed at a mean of 32.7 months (range, 18 to 44 months) after implantation. One patient underwent conversion for rupture, three for endoleaks (one each with types I, II, and III), and one for stent separation from the graft material without endoleak or aneurysm expansion. Three cases were approached via the midline, one through a bilateral subcostal incision, and one through a retroperitoneal incision. Supraceliac aortic control was used in all patients. Removal of two of the Vanguard grafts necessitated extension of the aortotomy above the level of the renal orifices. One perioperative death occurred. The mean operative blood loss was 4700 mL (range, 1850 to 9000 mL), and length of stay was 19.8 days (range, 7 to 42 days).The morbidity and mortality rates associated with late removal of endografts are significant. Removal of Vanguard devices can necessitate extension of the aortotomy above the renal arteries. We believe that control of the aorta well above the proximal fixation site is the key to removal and that continuous aortic exposure via retroperitoneal exposure is the best option in this situation.

Objective: The objective of this study was to define differences in perioperative hemodynamics and associated outcomes in patients who undergo carotid endarterectomy (CEA) with regional and general anesthesia. Methods: All the patients who underwent CEA during a 25-month period were reviewed, with a comparison of those who underwent operation with cervical block anesthesia (CB) with those who underwent operation with general anesthetic (GA). Baseline intraoperative and postoperative blood pressure and heart rate were recorded, and deviation from initial values was calculated. The administration of vasoactive medications was assessed. Operative time, intensive care unit admission, postoperative length of stay, and cardiac/neurologic morbidity were recorded. Results: From October 16, 1998, to December 1, 2000, 550 nonemergent CEAs were performed in 527 patients (226 with CB and 324 with GA). The patients in both groups were similar in age, presentation, and associated comorbidities. Although baseline blood pressure and heart rates were similar in both groups, those patients who underwent operation with GA had significantly greater intraoperative and postoperative hemodynamic variability and received more vasoactive medications during surgery (87% versus 51%; P

Objectives: The purpose of this study was to document outcome and adverse prognostic factors in patients requiring combined free tissue transfer and distal bypass grafting for otherwise nonreconstructible infrainguinal arterial occlusive disease and advanced tissue necrosis. Methods: Between July 1990 and November 1999, 65 patients, all of whom would have required at least below-knee amputation, underwent free tissue transfer in conjunction with infrainguinal bypass grafting at the University of Rochester. Preoperative variables were assessed for their influence on outcome with χ2 and outcome with life-table analysis with Cox proportionate hazard testing. Results: Free tissue transfer was performed synchronously with arterial reconstruction with autologous vein in 49 patients and after a previous functioning venous bypass graft in 16 patients. The 30-day mortality rate was 5%, and major complications occurred in another 16% of patients. Flap location, weight-bearing status, preexisting osteomyelitis, and the timing of bypass grafting relative to flap construction had no effect on outcome. All five free flap failures occurred within the first 30 days. All other flaps subsequently survived, even in seven patients whose bypass grafts thrombosed. Five-year limb salvage and patient survival rates were 57% and 60%, respectively, and 65% of patients regained meaningful ambulation. The combination of diabetes and dialysis-dependent renal failure was the strongest predictor of overall limb loss (P

Background: The traditional separation of vascular surgery and interventional radiology into distinct units is associated with inefficiencies in patient care, practice management, and training. Traditional departmental politics, discrepant clinical backgrounds and philosophies, fear of decreasing remuneration, and basic differences in education, training, and practice have all rendered mergers difficult. Methods: We have implemented a model that incorporates all the clinical, fiscal, and educational activities of the 2 former entities into a single unit. A 5-physician vascular surgery group, its noninvasive laboratory, and a 3-physician interventional radiology group were unified. The revenue was deposited into a single account from which all the expenses were paid. The net income of the joint unit was apportioned on a predetermined pro rata basis, with scaled percentages for each practitioner. In an effort to separate clinical decision making from economic pressures, the individual physician remuneration was not on the basis of productivity. Clinical volume, gross revenue, and remuneration were compared with the 12-month period that immediately preceded the merger and contrasted to the previous 3-year historical trend (HT). Results: The number of vascular surgical procedures fell after the merger (–9.3%; HT, +4.7%). By contrast, the number of interventional radiology procedures rose (+56.1%; HT, +15.2%), as did the number of noninvasive testing (+9.2%; HT, +3.5%). In concordance with the number of procedures, the gross revenue of vascular surgery fell (–23.7%; HT, +1.1%) and that of interventional radiology rose (+53.5%; HT, +46.0%). The increased efficiencies allowed the total expenses of the 2 units to fall (–13.2%; HT, +7.5%), and, despite the reduced revenue, the vascular surgeon remuneration was preserved (+0.7%; HT, –3.9%) and the radiology remuneration rose (+22.3%; HT, +8.3%). The merger allowed the vascular surgery fellows to actively participate in 26 interventional cases per month and the interventional radiology fellows to actively participate in 8 open surgical cases per month. Conclusion: The merger of vascular surgery and interventional radiology resulted in a decrease in the surgical procedures and revenue, with a corresponding increase in the interventional radiology procedures and revenue. Despite these effects, the physician remuneration increased as a result of the improved efficiencies in practice management and the reduction in expenses. The merger of the 2 units excludes the economic pressures from clinical decision making and appears to be warranted on the basis of the fiscal and educational benefits that are achieved. (J Vasc Surg 1998;28:1006-13.)

Renal arterial thrombosis, usually in association with aortic thrombosis, has been reported as a result of prolonged neonatal umbilical artery catheterization. A case of renal artery thrombosis attributable to umbilical artery catheterization, resulting in malignant renovascular hypertension, in a 15-day-old neonate, treated by catheter-directed thrombolysis through the involuting umbilical artery, was studied. Resolution of systemic hypertension and partial return of right renal function followed rapid thrombus dissolution. (J Vasc Surg 1998;28:949-53.)

Purpose: This study assessed whether multisegmental disease that is severe enough to require an inflow procedure adversely affects infrainguinal bypass patency, limb salvage, or patient survival rates. Methods: The records of 495 patients who underwent 551 infrainguinal bypass grafting procedures were reviewed. Saphenous vein and prosthetic grafts were evaluated separately. Graft patency rates, patient limb salvage rates, and patient survival rates in those grafts that arose from a reconstructed inflow source were compared with those that arose from normal, nonreconstructed inflow sources. When grafts had either hemodynamic failure or occlusion, the cause of failure was identified. Results: Four-year primary patency rates in vein grafts that arose from a reconstructed inflow sources were lower than those in grafts that arose from nonreconstructed inflow sources (41% vs 54%; p = 0.006). Assisted primary patency rates and secondary patency rates, however, were similar (62% vs 74% and 64% vs 77%, respectively). The 4-year primary patency rate (45% vs 55%), assisted primary patency rate (60% vs 60%), and secondary patency rate (60% vs 61%) in prosthetic grafts did not vary based on inflow source. The most common cause of graft failure was inflow failure, except in the vein grafts that did not require an inflow procedure, in which the most common cause of failure was graft failure. Inflow failure occurred in 24% and 22% of the vein and prosthetic grafts with multisegmental disease, respectively, but in only 7% (p < 0.001) and 10% (p < 0.05), respectively, of those that arose from normal nonreconstructed inflow. The presence of an inflow procedure did not affect limb salvage rates or patient survival rates, regardless of graft material. Conclusions: Long-term patency rates, patient limb salvage rates, and survival rates in patients with a reconstructed inflow source were similar to those of patients with a normal nonreconstructed inflow. A major cause of occlusion is inflow failure, and this occurs in a greater proportion of patients with multisegmental disease. These patients, in particular, may benefit from patient surveillance to screen for progression of their inflow disease and to allow for intervention before infrainguinal graft occlusion. (J Vasc Surg 1997;26:928-38.)

Purpose: Long-term success of endoluminally placed grafts for exclusion of abdominal aortic aneurysms (AAAs) relies on secure fixation at the proximal and distal cuffs and, as such, assumes that the fixation sites will not dilate over time. Data regarding this issue, however, are not yet available. This study was performed to evaluate the region of the proximal anastomosis in patients many years after having undergone conventional AAA repair to determine the potential for late dilatation after placement of an endoluminal device. Methods: Three hundred forty-six patients underwent repair of an infrarenal AAA at our institution between January 1985 and December 1990. Of 97 eligible living patients, 33 both had their original CT scans available and underwent repeat scanning at a mean of 88.6 ± 23.8 months (mean ± SD; range, 40 to 134 months) after repair. Results: The overall 5-year survival rate was 73%. The mean preoperative infrarenal aortic cuff diameter by CT scan was 24.5 ± 3.7 mm (range, 19 to 33 mm). At an average of 89 months after repair, the mean infrarenal aortic diameter increased 4.3 mm to 28.8 ± 7.7 mm (range, 20 to 52 mm; p = 0.0004 by t test). The proximal cuff at this time measured 30 mm or more in 11 patients (33%), and as early as 6 years after operation three of the seven patients (43%) scanned within this time period had cuffs that were dilated to 30 mm or more. Late dilatation to 30 mm or more was rare (16%) in patients who had preoperative cuffs that measured 27 mm or less. The mean late iliac artery size was 16.9 ± 8.9 mm (range, 10 to 52 mm), and 30% (10 of 33) measured 20 mm or more. Conclusions: One third of all patients who survive AAA repair experience significant dilatation of their proximal aortic cuff over time. Proximal dilatation is rare but not absent in patients who have smaller initial aortic cuff diameters. This dilatation rarely causes problems after conventional suture fixation, but the long-term implications of cuff dilatation after endoluminal repair are unclear. Our findings suggest that endovascular aortic prostheses that have the ability to continue to self-expand many years after implantation may be required and that endovascular prostheses may not be the best option for patients who have a long life expectancy or for those who have preoperative proximal cuffs greater than 27 mm.

Purpose: Despite advantages demonstrated in vitro, no single thrombolytic agent has been clearly shown to be superior to another in the clinical setting. Prourokinase has recently received attention as a new thrombolytic agent with higher fibrin specificity. The thrombolytic activity of prourokinase, however, remains ill defined. The purpose of this study was to evaluate thrombolysis with prourokinase in comparison to urokinase in vitro. Methods: We used an in vitro parallel channel perfusion model that simulates catheter-directed thrombolysis in the peripheral arterial system. Radiolabeled thrombi were subjected to 90 minutes of endhole catheter-directed infusion with either prourokinase 5000 IU/ml, urokinase 5000 IU/ml; or 5% dextrose in water at 4 ml/hr. Results: Prourokinase and urokinase were found to be equivalent with respect to thrombolytic effect. Percent lysis was maximal at 90 minutes in both the urokinase and prourokinase groups. Prourokinase and urokinase were found to be equally effective in restoring flow through thrombosed graft segments. Conclusions: Prourokinase appears to offer little benefit over urokinase with respect to thrombolytic activity in an in vitro model that closely resembles the clinical setting. If prourokinase is to be accepted as an alternative to urokinase, advantages must relate to differences in fibrin specificity.

Carotid endarterectomy has been used to treat carotidbifurcation disease for more than 50 years. Over this periodof time, the indications for repair have been refined and thesurgicaltechniquehasundergoneminormodification.Thisoperation has held up to the scrutiny of large multicenterrandomized trials, and more carotid endarterectomies arenow being performed than at any time in the history of theoperation. Although a cervical incision is inescapable, ca-rotid endarterectomy is associated with a remarkably lowmorbidity and mortality, especially when performed inpatients without severe medical comorbidities.Despite the wide acceptance of carotid endarterec-tomy,aconsensusstatementthatsummarizestheevidence-based recommendations for treatment has never been pre-pared by the vascular surgical societies. By contrast, severalinterventional radiology societies have recently publishedguidelines for carotid artery stenting, a relatively new ther-apeutic option.

Intraoperative autotransfusion is frequently used in aortic surgery, despite the paucity of data regarding its safety and efficacy. This study was designed to compare whole blood autotransfusion with homologous transfusion for the replacement of blood lost during abdominal aortic procedures.Whole blood autotransfusion was evaluated in 200 patients undergoing aortic reconstructive procedures during a 3-year period. Collection and reinfusion of unwashed filtered shed blood was undertaken in 100 patients, and clinical, laboratory, and economic parameters were compared with those in a group of 100 patients undergoing aortic operation with homologous banked blood replacement.The two groups were comparable with respect to demography, the type of procedure, baseline laboratory profile, and the frequency of coexistent medical illnesses. The amount of blood salvaged and reinfused averaged 1729 +/- 68 ml in the autotransfusion group. Patients undergoing autotransfusion received a mean of 0.6 +/- 0.1 units of banked blood during operation, compared with 3.4 +/- 0.1 units in the homologous group (p0.001). Operative morbidity and mortality rates were comparable between the groups, as were length of hospital stay and total hospital costs. Coagulopathy, renal insufficiency, abnormalities of oxygen exchange, and electrolyte disorders were infrequent. Autotransfusion offered significant advantages over homologous blood replacement with respect to improved preservation of circulating platelets (201 +/- 9 vs 157 +/- 6 x 10(3)mm3, p0.001) and coagulation factors (242 +/- 11 vs 196 +/- 14 mg fibrinogen/dl, p0.01) and limitation of exposure to homologous blood (34% vs 92%, p0.001). There was a significant cost advantage with the use of autotransfusion, with an average savings of $288 in hospital expenses associated with blood products and infusion equipment. Patients undergoing autotransfusion demonstrated aberrations in fibrin degradation products (33 +/- 4.4 vs 9.6 +/- 3.2 micrograms/ml, p0.001) and free plasma hemoglobin (29 +/- 9.1 vs 9.4 +/- 0.5 mg/dl, p0.05), but these laboratory abnormalities did not acquire clinical significance.These data suggest that autotransfusion of unwashed, filtered blood is a safe and efficacious alternative to homologous blood replacement in patients undergoing major aortic reconstructive procedures.