Secondary Aortoenteric Fistula Research Articles

Endovascular Treatment of a Bleeding Secondary Aorto-Enteric Fistula. A Case Report with 1-Year Follow-up

We report a patient with life-threatening gastrointestinal bleeding caused by a secondary aorto-enteric fistula. Because the patient had several comorbid conditions, we succesfully stopped the bleeding by endovascular placement of a bifurcated aortic stent-graft. The patient developed periaortic infection 4 months later, but he was managed with antibiotics. The patient is well 1 year after the procedure.

Diagnosis of Aortoenteric Fistulas with CT Angiography

To describe the diagnostic findings of primary and secondary aortoenteric fistulas (AEFs) at computed tomographic (CT) angiography in a cohort of patients known to have AEF and to correlate those findings with those from endoscopic gastroduodenoscopy (EGD) and surgery. CT angiography was performed in nine patients with AEF. There were four men and five women aged 43-85 years (mean age, 67 years). All CT angiograms were retrospectively reviewed for signs of AEF. Reports from EGD, surgery, and pathologic examination were also reviewed. One patient had a primary AEF, and eight patients had a secondary AEF. Findings at CT angiography were suggestive of the diagnosis in all nine patients. The two definitive CT angiographic findings were identification of the graft within the bowel lumen in two patients (22%) and active extravasation in one patient (11%), allowing the definitive diagnosis in three of the nine patients (33%). Secondary signs, which helped predict the high likelihood of the diagnosis but could also be seen in graft infection or inflammation without AEF, were as follows (in descending order of frequency): effacement of the periaortic or perigraft fat plane and the fat plane between the aorta and bowel (nine patients, 100%), perigraft soft tissue (nine patients, 100%), bowel wall thickening adjacent to the graft (eight patients, 89%), perigraft fluid (seven patients, 78%), perigraft hematoma (six patients, 67%), pseudoaneurysm or aneurysm bulge (six patients, 67%), ectopic gas (five patients, 56%), and dystrophic vascular graft calcification (one patient, 11%). The diagnosis was confirmed surgically in seven patients and with clinical follow-up in two. CT angiography is well suited for helping make or suggesting the diagnosis of AEF and is potentially more accurate than EGD.

Primary Aortoenteric Fistula — An Uncommon Cause for GI Bleeding

A 68-year-old white male presented to an emergency room with acute onset of abdominal pain and hematochezia. The patient's pain had subsided upon reaching the ER. Physical exam revealed stable vital signs and a tender abdomen without masses or bruits. Diagnostic testing included a tagged red blood cell scan suggesting bleeding within the sigmoid colon, followed by endoscopy which did not identify a culprit lesion. Within 24 hours of hospitalization the abdominal discomfort and bleeding returned. Further imaging with CT angiogram visualized an infrarenal aneurysm with a subtle leak of contrast into the duodenum. He was transferred to a tertiary care center and became hemodynamically unstable with persistent hematochezia upon arrival. Upper endoscopy was repeated but was limited by active pooling of blood. Angiography immediately followed this procedure and confirmed an aortoduodenal fistula (figures 1 and 2). The patient was taken emergently to the operating room for surgical repair and died intraoperatively from massive exsanguination. A primary aortoenteric fistula (PAEF) is a rare diagnosis. Unlike a secondary aortoenteric fistula, a PAEF is an abnormal communication between the aorta and enteric system that develops without prior history of aortic graft placement. The natural history is self-limited bleeding which can escalate to massive exsanguination within 24 hours. For this reason, early suspicion, diagnosis, and treatment are paramount to patient survival. Unfortunately, the bleeding pattern in a PAEF can make diagnostic studies misleading, and current technology may preclude a perfect diagnostic tool. The experience of this case suggests the need for heightened physician awareness of PAEFs and a lower threshold for surgical intervention. [figure 1][figure 2]Figure 1Figure 2

Evolving strategies for the treatment of aortoenteric fistulas

Aortoenteric fistulas (AEFs) are a rare but often fatal cause of gastrointestinal bleeding. Operative repair of AEF has been historically associated with extremely high morbidity and mortality. We reviewed our experience of open surgical and endovascular treatment of AEF to compare outcomes over a contemporaneous time period. Over a 9-year period between January 1997 and January 2006, 16 patients (11 men and 5 women) were diagnosed with and treated for AEFs. Seven patients underwent open surgical repair, and nine, with anatomically suitable lesions, underwent endovascular repair. The outcome after treatment of these patients was investigated for survival, perioperative complications, length of hospital stay, and long-term disposition. Three primary and 13 secondary AEFs were treated. The mean time from the initial aortic operation until AEF diagnosis was 5.9 years (range, 0.7-12.2 years) for patients with secondary AEFs. The overall 30-day mortality rate was 18.8%. One intraoperative death and one in-hospital death secondary to multisystem organ failure occurred in patients undergoing open repair. One in-hospital death related to persistent sepsis occurred in the endovascular group. The overall perioperative complication rate was 50.0%. Complications in the open group included sepsis, renal failure, bowel obstruction, and pancreatitis. Complications in the endovascular group were related to persistent sepsis. The mean in-hospital length of stay was significantly longer for patients undergoing open repair compared with endovascular repair (44.0 vs 19.4 days; P = .04). Four (80%) of five patients who were discharged from the hospital in the open group were placed in skilled nursing facilities, and seven (87.5%) of eight patients discharged in the endovascular group returned home. The median overall survival after hospital discharge was 23.1 months. There were no late aneurysm-related deaths or late deaths related to septic complications. Patients with AEFs have limited overall survival. Endovascular therapy offers an alternative to open surgical repair, seems to be associated with decreased perioperative morbidity and mortality and a shorter in-hospital stay, and allows for acceptable survival given the presence of coexisting medical comorbidities. Furthermore, endovascular repair provides a therapeutic option to control bleeding and allow for continued intervention in a stabilized setting.

Successful Endovascular Treatment of Bleeding Aortoenteric Fistula: A Case Report

Aortoenteric fistula (AEF) is an infrequent but disastrous complication of open abdominal aortic repair. Left untreated, it has a 100% fatality rate. The traditional approaches to the repair of secondary AEF (SAEF) are associated with average mortality rates of 21-59% and numerous major complications. Here, we report a case of acute gastrointestinal bleeding due to SAEF, successfully treated with endovascular stent graft repair. At 1-year follow-up, the patient was doing well without any signs of recurrent fistula. Endovascular treatment of AEF provides another treatment option that may be particularly valuable in patients whose comorbidities would preclude open repair.

Endovascular Repair of a Bleeding Secondary Aortoenteric Fistula with Acute Leg Ischemia: a Case Report and Review of the Literature

The endovascular approach seems very attractive for patients with bleeding secondary aortoenteric fistulas (SAEF) and limb ischemia, particularly when there is no associated sepsis. Aortic stent-grafting can rapidly seal the aortoenteric communication and ensure limb reperfusion. In the present case, a 53-year-old man with a bleeding SAEF and acute leg ischemia underwent aortic stent-grafting. Ten months later, CT and leukocyte scan (Tc-99m) showed no evidence of graft infection and the patient remains well 18 months postoperatively. In the typical patient with a bleeding SAEF, endoluminal treatment, if feasible anatomically, should be considered as first-choice treatment whether it represents a "bridging" step or a "definite" solution.

Bacteriological implications in the pathogenesis of secondary aortoenteric fistulas.

Abstract The role of bacterial infection in the pathogenesis of aorto-enteric fistula was examined by a collective review of the clinical features and bacteriology in 213 patients. The most common presentation, gastrointestinal bleeding, occurred in 49 per cent of patients, although 32 per cent had systemic or local signs of infection as a presenting symptom. Results of intraoperative cultures were available in 115 patients, 33 of whom had two or more isolates. The predominant organisms were Escherichia coli, Staphylococcus aureus, group D Streptococcus and Bacteroides spp. The Gram-positive aerobic cocci predominated in fistulas developing within the first postoperative year which is compatible with a primary infection due to intraoperative contamination with skin flora. The Enterobacteriaceae and anaerobes showed no predilection for early or late occurring fistulas, suggesting that infection in these patients may be secondary to mechanical erosion of the graft through the adjacent duodenum. In either event, the likelihood that the aorto-enteric fistula is complicated by prosthetic infection should be seriously considered by the surgeon in planning the operative procedure.

Staged Endovascular Stent-grafting and Surgical Treatment of a Secondary Aortoduodenal Fistula

Secondary aortoenteric fistula is a dramatic, rather infrequent late complication occurring mostly after abdominal aortic surgery. Currently, graft excision and in situ bypass is considered the treatment of choice, but it is associated with significant mortality and morbidity. Herein, we describe the case of a secondary aortoduodenal fistula treated by staged endovascular stent-grafting and surgical closure of the fistula. Forty days after stent-grafting, Tc-99m-HMPAO labelled leukocyte scanning failed to identify leukocyte infiltration of the graft and there were no clinical signs of infection. At 8-month follow up, the patient was asymptomatic.

Improved outcomes in the recent management of secondary aortoenteric fistula

We reviewed the presentation, management, and late events in a recent experience with aortic graft-enteric communications (secondary aortoenteric fistula) to identify variables associated with poor outcomes. Since 1991, 29 patients (19 men, 10 women; mean age, 70) presented with a secondary aortoenteric fistula. The duration from aortic graft implantation to aortoenteric fistula development ranged from 8 months to 180 months (mean, 47 months). Presenting symptoms included gastrointestinal bleeding (n = 25), sepsis and retroperitoneal abscess (n = 3), and ruptured para-anastomotic aneurysm (n = 1). One third (10/29) of patients were hypotensive at presentation. Repair was accomplished by graft excision with axillobifemoral bypass (17 simultaneous, 8 staged), graft excision with in situ deep vein replacement (n = 2), or graft excision with rifampin-treated prosthetic replacement (n = 2). Mean follow-up was 51 months, and the incidence of late events was reported by life table methods. The operative (< or = 30-day) mortality rate was 21%, with shock at presentation (P < .01), the need for preoperative transfusion (P < .01), and use of suprarenal aortic clamping during aortoenteric fistula repair (P = .03) associated with lethal outcome. Cumulative mortality related to aortoenteric fistula management was only 24% within an overall 5-year survival rate of 61%. Freedom from recurrent infection or amputation was 86% and 88% at 5 years, respectively, and assisted graft patency was 79%. Presence of staphylococcal species in 22% of patients and occasional operative findings of adjacent perigraft "biofilm" suggests that underlying indolent graft infection may contribute to the development of aortoenteric fistula in some cases. Outcomes associated with aortoenteric fistula repair were surprisingly favorable in the absence of preoperative hemodynamic instability.

Fístulas aortoentéricas: presentación clínica y hallazgos por tomografía computarizada helicoidal

Aortoenteric fistula (AEF) is an uncommon complication of abdominal aorta aneurysms. They are divided into two types: primary AEF due to a spontaneous communication of the lumen of an aortic aneurysm and an intestinal loop, usually the duodenum, and secondary AEF, which are more common and occur in patients who have undergone surgical repair of aneurysms with prosthetic implants. The most frequent presenting sign of AEF is upper gastrointestinal bleeding. Clinical suspicion is essential in the diagnostic approach to AEF and the most commonly used techniques for its diagnosis are endoscopy and computed tomography (CT). However, it is not unusual for the results of these techniques to be negative and for the diagnosis to be made at surgery. We present three cases of AEF (one primary) with distinct patterns of upper gastrointestinal bleeding, in which preoperative diagnosis was allowed by clinical and helical CT findings. We discuss the role of this technique in the diagnosis of this entity and describe the findings that allow AEF to be suspected or confirmed.

Secondary Aortoduodenal Fistula with a Fatal Outcome: Report of Six Cases

Secondary aortoenteric fistulas (AEFs) are a well-known but uncommon cause of gastrointestinal hemorrhage. They usually occur secondary to reconstructive surgery of an abdominal aneurysm. We report six cases of secondary aortoduodenal fistulas, involving patients who, despite presenting with classic "herald bleeding," died as a result of delayed operative intervention. We also discuss the pathogenesis, clinical presentation, and diagnosis of AEFs, emphasizing the value of clinical suspicion and negative endoscopy in establishing the diagnosis and the need for early operative intervention.

Paraprosthetic Extravasation of Enteric Contrast: A Rare and Direct Sign of Secondary Aortoenteric Fistula

Peirce RM, Jenkins RH, MacEneaney P(AQ1) n aortoenteric fistula is a communication between the aorta and the gastrointestinal tract. This condition is a rare cause of massive, lifethreatening gastrointestinal hemorrhage. Primary aortoenteric fistulas are typically caused by arteriosclerosis and occur in the elderly. Secondary aortoenteric fistulas (SAEFs) are uncommon complications of vascular surgical procedures. Presentations of SAEF can be straightforward but are notorious for elusive and temporally remote presentations. The symptoms of SAEF are variable and depend on the site of the graft infection. Infected femoral components in a patient may present with a fever, local tenderness, and, occasionally, purulent drainage through a sinus tract in the thigh. Intraabdominal infections tend to be more nebulous; malaise, back pain, elevated white blood cell count (WBC), and abdominal complaints are the usual presentation. These features mimic more common disease entities, making diagnosis difficult. Proving the existence of an SAEF radiographically can be difficult. In this article, paraprosthetic extravasation of enteric contrast, a rare and direct sign of SAEF, verified aorto-to-enteric communication on CT. Case Report A 72-year-old woman arrived at our emergency department with a fever, elevated WBC count, abdominal pain, and purulent groin drainage (Fig. 1). The patient had aortobifemoral prosthesis placement at an outside institution 6 weeks earlier. Because of abnormal renal function, a CT scan of the abdomen and pelvis was performed with enteric contrast only (meglumine diatrizoate [Gastrografin], Mallinckrodt). CT revealed a ring of high-contrast material and air in the paraprosthetic space of the left iliac limb of the graft. The contrast and air tracked superiorly, to the level of the aortic portion of the graft and inferiorly into the groin. This represented leakage of enteric contrast from the bowel. CT findings indicated an aortoenteric fistula and were confirmed at surgical exploration. Laparotomy revealed an infected aortobifemoral graft with a large intraabdominal collection of purulent fluid just behind the duodenum, anterior to the graft. The infected fluid collection extended into the left limb of the graft, with associated erosion into the adjacent sigmoid colon. The infected graft was removed and an aorto-to-popliteal bypass graft was inserted. Culture of the wound drainage revealed mixed bowel flora. The patient was treated with IV antibiotics and experienced a complicated postoperative course. However, the patient fully recovered and returned home weeks later.

Aortoenteric fistula to the sigmoid colon—case report

Aortoenteric fistula is defined as a communication between the aorta and any adjacent segment of the bowel. It may be primary or secondary. The former occurs de novo in patients with intestinal or vascular diseases, whereas secondary aortoenteric fistula is a rare and dreadful complication of aortic reconstruction with vascular prosthesis. We report a case of a 62-year-old man who presented to the emergency department with acute rectal bleeding. The patient had previous aortoiliac surgery with the utilization of an aorto-bifemoral vascular graft. Diagnosis of secondary aortoenteric fistula was made between the aortoiliac graft and sigmoid colon. After exploratory laparotomy, Hartmann's procedure, excision of the graft, oversewing of the aortic stump, and axilobifemoral bypass were successfully performed. This study reports a rare type of secondary aortoenteric fistula to the left colon, and it describes an unusual and successful surgical treatment.

Allograft replacement for infrarenal aortic graft infection: early and late results in 179 patients

Objectives We evaluated early and late results of allograft replacement to treat infrarenal aortic graft infection in a large number of patients and compared the results in patients who received fresh allografts versus patients who received cryopreserved allografts. Methods From 1988 to 2002 we operated on 179 consecutive patients (mean age, 64.6 ± 9.0 years; 88.8% men). One hundred twenty-five patients (69.8%) had primary graft infections, and 54 patients (30.2%) had secondary aortoenteric fistulas (AEFs). Fresh allografts were used in 111 patients (62.0%) until 1996, and cryopreserved allografts were used in 68 patients (38.0%) thereafter. Results Early postoperative mortality was 20.1% (36 patients), including four (2.2%) allograft-related deaths from rupture of the allograft (recurrent AEF, n = 3), all in patients with fresh allografts. Thirty-two deaths were not allograft related. Significant risk factors for early mortality were septic shock ( P < .001), presence of AEF ( P = .04), emergency operation ( P = .003), emergency allograft replacement ( P = .0075), surgical complication ( P = .003) or medical complication ( P < .0001), and need for repeat operation ( P = .04). There were five (2.8%) nonlethal allograft complications (rupture, n = 2; thromboses, which were successfully treated at repeat operation, n = 2; and amputation, n = 1), all in patients with fresh allografts. Four patients (2.2%) were lost to follow-up. Mean follow-up was 46.0 ± 42.1 months (range, 1-148 months). Late mortality was 25.9% (37 patients). There were three (2.1%) allograft-related late deaths from rupture of the allograft, at 9, 10, and 27 months, respectively, all in patients with fresh allografts. Actuarial survival was 73.2% ± 6.8% at 1 year, 55.0% ± 8.8% at 5 years, and 49.4% ± 9.6% at 7 years. Late nonlethal aortic events occurred in 10 patients (7.2%; occlusion, n = 4; dilatation < 4 cm, n = 5; aneurysm, n = 1), at a mean of 28.3 ± 28.2 months, all but two in patients with fresh allografts. The only significant risk factor for late aortic events was use of an allograft obtained from the descending thoracic aorta ( P = .03). Actuarial freedom from late aortic events was 96.6% ± 3.4% at 1 year, 89.3% ± 6.6% at 3 years, and 89.3% ± 6.6% at 5 years. There were 63 late, mostly occlusive, iliofemoral events, which occurred at a mean of 34.9 ± 33.7 months in 38 patients (26.6%), 28 of whom (73.7%) had received fresh allografts. The only significant risk factor for late iliofemoral events was use of fresh allografts versus cryopreserved allografts ( P = .03). Actuarial freedom from late iliofemoral events was 84.6% ± 7.0% at 1 year, 72.5% ± 9.0% at 3 years, and 66.4% ± 10.2% at 5 years. Conclusions Early and long-term results of allograft replacement are at least similar to those of other methods to manage infrarenal aortic graft infections. Rare specific complications include early or late allograft rupture and late aortic dilatation. The more frequent late iliofemoral complications may be easily managed through the groin. These complications are significantly reduced by using cryopreserved allografts rather than fresh allografts and by not using allografts obtained from the descending thoracic aorta.

Early and Long-term Results of Conventional Surgical Treatment of Secondary Aorto-enteric Fistula

Objective. To retrospectively evaluate early and late results of surgical treatment of secondary aorto-enteric fistulas (SAEFs) with prosthetic excision and extra-anatomic bypass (conventional treatment) in a single centre institution (teaching hospital). Materials and methods. Between January 1990 and March 2002, 30 patients underwent conventional surgical treatment for SAEF. Data concerning these operations were collected in a dedicate database and 30-day mortality, patency and limb salvage rates were evaluated by mean of chi-square test and logistic regression analysis. Clinical and ultrasonographic follow-up was performed; late results were evaluated by mean of Kaplan–Meyer curves. Results. Thirty day mortality rate was 26% (8 patients). Timing and sequence of interventions (simultaneous or staged, prosthetic excision or revascularization before) had no significative influence on perioperative mortality. There were six extranatomic bypass thromboses at 30 days, but no amputation. Mean duration of follow-up was 24 months; estimated 12- and 24-month survival rates were 60 and 50%, respectively. There were better results in terms of long-term survival in patients undergone prosthetic graft excision before. Primary patency rate was 62% and limb salvage rate was 95%, both at 24 months. Two prosthetic graft reinfections occurred during follow-up (9%). Cumulative reinterventions rate during follow-up was 18%. Conclusions. Conventional surgical treatment of SAEF permitted, in our experience, satisfactory early and long terms results, with fair rates of patency and limb salvage. Surgical timing and sequence do not seem to affect early results.

Aorto-Enteric Fistula is a Serious Complication to Aortic Surgery. Modern Trends in Diagnosis and Therapy

Secondary aorto-enteric fistula (AEF) is a serious, but rare, complication following surgery of the abdominal aorta. AEF occurs in 0.3–2%, but is associated with a hospital mortality between 25–90%. It is also associated with an important morbidity with a lower limb amputation rate of 9%, and a 15% risk for renewed graft infection. Nine secondary AEF were surgically treated. The hospital mortality was high, 44% (4/9). Recurrent AEF was observed in 1 patient 2 years after the first operation. During follow-up 2 patients had mild infections which were resolved by antibiotic treatment. Diagnostic modalities, and recent advancements in surgical treatment as well as preventive measures are discussed.

Aorto-enteric fistula is a serious complication to aortic surgery. Modern trends in diagnosis and therapy

Secondary aorto-enteric fistula (AEF) is a serious, but rare, complication following surgery of the abdominal aorta. AEF occurs in 0.3–2%, but is associated with a hospital mortality between 25–90%. It is also associated with an important morbidity with a lower limb amputation rate of 9%, and a 15% risk for renewed graft infection. Nine secondary AEF were surgically treated. The hospital mortality was high,44% (4/9). Recurrent AEF was observed in 1 patient 2 years after the first operation. During follow-up 2 patients had mild infections which were resolved by antibiotic treatment. Diagnostic modalities, and recent advancements in surgical treatment as well as preventive measures are discussed.

Long-term Survival Following Recurrent Secondary Aorto-Enteric Fistula in a Patient with Bechet's Disease

Long-term Survival Following Recurrent Secondary Aorto-Enteric Fistula in a Patient with Bechet's Disease

Uso de una ‘cápsula endoscópica’ para el diagnóstico de fístulas aortoentéricas. A propósito de un caso

Summary Introduction Aortoenteric fistulas or enteric erosion by prosthetic graft in the aortic territory in septic patients can be difficult to diagnose because of its, sometimes masked and insidious, clinical features, which makes early diagnosis one of the best guarantees when establishing a quick-acting effective therapy. Casereport Male aged 66 who had been submitted to surgery five years earlier for an aortobifemoral bypass because of an aorto-iliac occlusive pathology. At our centre he presented with a septic picture with a large retroperitoneal abscess detected by means of a computerised axial tomography (CAT) scan, and which covered the left branch of the graft. Suspected diagnosis was a secondary aortoenteric fistula caused by pressure from the duodenum on the graft, and the digestive tract was explored by using an ‘endoscopic capsule’, which consists in an encapsulated, disposable colour camera that shows images compatible with the direct visualisation of the graft through the opening of the duodenum. The diagnosis of enteric erosion by prosthetic graft was confirmed during the surgical intervention and the infected graft was removed with ligature of the aortic stump, following an axillo-bifemoral extra-anatomical bypass. The retroperitoneal abscess was also cleaned and drained at the same time. Conclusion The use of capsule endoscopy is considered to be a valid option and another possible method of diagnosis in the management of primary and secondary aortoenteric fistulas or enteric erosion by prosthetic grafts, together with classical endoscopy, when the lesions are located distally to the fourth portion of the duodenum or when other imaging techniques are not conclusive.

Endovascular repair of bleeding aortoenteric fistulas: A 5-year experience

Purpose: Aortoenteric fistula (AEF) is an uncommon but catastrophic complication that can occur either primarily or after aortic reconstruction. Untreated, it is uniformly fatal. Conventional surgical management is associated with a perioperative mortality rate of 25% to 90% and frequent major complications. We reviewed our experience with the endovascular treatment of both primary and secondary AEFs in an effort to determine whether endovascular repair is a less morbid alternative to traditional surgical treatment in select patients. Methods: In a 5-year period, seven high-risk patients who had bleeding and an AEF documented by means of radiology or endoscopy (2 primary, 5 secondary) were treated with coil embolization (1) or placement of an endovascular aortic stent graft (3 aortouniiliac, 2 tube, 1 bifurcated). One patient underwent computed tomography (CT)-guided percutaneous catheter drainage of an infected perigraft collection. The average follow-up period was 27 months (range, 11-66 months), and follow-up consisted of physical examination, complete blood count, and contrast-enhanced helical CT scanning at 3, 6, and 12 months and yearly thereafter. All patients were treated with intravenous antibiotics perioperatively and were prescribed life-long oral antibiotics on discharge. Results: There was one perioperative death (14%) caused by fungal sepsis. Persistent sepsis after stent-graft placement necessitated laparotomy and bowel resection in one patient. One patient had three bouts of recurrent sepsis that were successfully treated with a change of antibiotic. There were three late deaths (43%) unrelated to the procedure or AEF. Three patients (43%) were alive and well an average of 36 months (range, 23-67 months) after the procedure, with no clinical or radiologic evidence of recurrent bleeding or infection. Conclusion: Endovascular management of AEFs is technically feasible and may be the preferred treatment in select patients with bleeding and no signs of sepsis. In the setting of gross infection, it may also be considered in high-risk patients as a bridge to more definitive treatment after hemodynamic stabilization and optimization. (J Vasc Surg 2001;34:1055-9.)