Femoral anastomotic aneurysms

Nahtaneurysmen - Ätiopathogenese, Symptomatologie, Diagnostik, Therapie, Outcome und Einflussfaktoren nach offen gefäßchirurgischer und interventioneller Rekonstruktion

Hintergrund Die über die letzten Jahre/Jahrzehnte ausgebaute und optimierte gefäßchirurgische Grundversorgung hat auch das Fallaufkommen von Sekundärkomplikationen wie das Nahtaneurysma (NA) wesentlich erhöht.

Ziel Darstellung der sekundären Versorgungsdiagnose NA in ihrem/r Fallaufkommen, Ätiopathogenese, Symptomatologie, Diagnostik, periinterventionellem/-operativem Management und Outcome, basierend auf selektiven Referenzen der medizinisch-wissenschaftlichen Literatur und eigenen klinischen Versorgungserfahrungen.

Methode Narratives Review

Ergebnisse

Schlussfolgerung Das NA als relevante Versorgungsgröße ist inzwischen längst mit in den Fokus eines basalen gefäßchirurgischen/-interventionellen Betreuungsprofils gerückt, dem sich der Gefäßchirurg/-interventionalist aufgrund der bestehenden Herausforderung hinsichtlich des anspruchsvollen diagnostischen und therapeutischen Managements mit seiner ganzen fachspezifischen Kompetenz widmen muss.

Repair of an Anastomotic Pseudoaneurysm with a Novel Hybrid Technique

INTRODUCTION

Anastomotic false aneurysms are a late complication of aortic grafting. Treatment usually consists of débridement of the degenerated tissue and placement of a short interposition graft. In infectious situations, graft excision is required.

PATIENT HISTORY

An 80-year-old frail man with numerous comorbidities presented to clinic with an anastomotic pseudoaneurysm (PSA) between the left limb of an aortobifemoral Dacron graft and the common femoral artery (FA).

TECHNICAL DETAILS

The superficial FA (SFA) and deep FA (PFA) were exposed and controlled from an anterior thigh approach. Sheaths were inserted in each artery. An Amplatzer II vascular plug (Abbott, Abbott Park, IL) was deployed in the PFA. A Viabahn (Gore, Flagstaff, AZ) was first deployed in the left limb of the Dacron graft and into the proximal SFA. A Viabahn VBX stent (Gore, Flagstaff, AZ) was then deployed from inside the Viabahn and going proximally further into the limb of the bifurcated Dacron graft. The proximal end of the Viabahn VBX was flared with a larger balloon. The arteriotomies in the SFA and PFA were then used to create a side-to-side anastomosis. There were no immediate complications. On 6 months follow-up, the PSA sac was noted to have decreased in size, and the stents to be patent with no endoleak.

DISCUSSION

Elective surgical repair of anastomotic PSAs is preferred since emergent repair has significantly higher morbidity and mortality. Still, open elective repair has its own mortality and limb loss risks in addition to postoperative wound infection, seroma, hematoma, and recurrence, along with myocardial infarction and stroke. The novel procedure we performed eliminated the risk factors of redo groin incision and added easier-to-control vessels in a clean field. With this procedure being performed more often in the future, these changes will hopefully prove to reduce complications while preserving flow in both the SFA and PFA.

Stent graft repair of anastomotic pseudoaneurysm of femoral-popliteal bypass graft following patch angioplasty

Pseudoaneurysm (PA) following vascular reconstruction is a complication of bypass surgery. Historically, the mainstay of treatment was an open repair; the surgical management consisted of resection of the initial graft with reimplantation of a new bypass either into the original arteriotomy or to a more distal target. Placement of a stent graft to exclude the PA is a viable option. We present a case of an 85-year-old man with prior history of polytetrafluoroethylene femoral-popliteal bypass now with an 8 × 5.6 cm PA of the distal anastomosis site treated with endovascular placement of a Viabahn stent.

Percutaneous Stent-Graft Repair of Anastomotic Pseudoaneurysms following Vascular Bypass Procedures: A Report of Two Cases

Anastomotic pseudoaneurysms are common entities following vascular bypass procedures and, if left untreated, serious complications such as thromboses, infection, and rupture can frequently occur. Therefore, attempts to employ various methods of repair have been utilized in treating anastomotic pseudoaneurysms to maximize operational success and future risk reduction. Herein, the authors report two cases of anastomotic pseudoaneurysms which were repaired percutaneously utilizing a combination of strategies such as careful preoperational image planning, multiple commercially available devices, and secondary embolization techniques.

[Anastomotic false aneurysms after under-diaphragmatic bypasses: about 25 cases]

The purpose of our study is to determine the causes and the management of anastomotic aneurysms. We report the cases of 25 patients with a mean age of 64 years at the time of initial surgical revascularisation. The mean interval between the first operation and the occurrence of anastomotic aneurysm is 5 years (range 2 months-11 years). The treatment consists on the interposition of a graft in 8 patients, anastomotic angioplasty in 9 patients and the reconstruction of the anastomosis in 8 patients. Hospital mortality was 20%. Late death occurs 3 patients and the long-term morbidity was evaluated at 22%. A recurrence of anastomotic false aneurysm occurred in 4 patients (16%) (Range 7 months-1 year). In conclusion anastomotic false aneurysm is one of the major complications of vascular reconstruction; careful follow-up can detect the rare instances of anastomotic aneurysm and reoperation can be accomplished with a low-rate of adverse outcome.

Ruptured false iliac artery aneurysm--a case report from Nigeria

A 23 year old male Nigerian presented to the Nephrology unit of the Olabisi Onabanjo University Teaching Hospital, Sagamu, Nigeria with features of chronic renal failure secondary to chronic glomerulonephritis. He was referred to the surgical department of the hospital on account of severe torrential uncontrollable bleeding from an infected cannulation site. He was maintained on regular hemodialysis but developed femoral triangle sepsis at the cannulation site and aneurysm of the external iliac artery. The aneurysm later ruptured with severe jet exsanguinations bleeding. Exploration revealed a-4 cm rent in the external iliac artery that was sutured with 6/0 prolene, interrupted, using clamp and suture technique. Perfusion was satisfactory in the immediate post-operative period. The patient was transfused with 11 pints of blood within 12 hours and had an uneventful post-operative period.

Infected pseudoaneurysm of the femoral artery secondary to melioidosis infection of a previous femoropopliteal bypass graft

Infected arterial aneurysm or pseudoaneurysm caused by Burkholderia pseudomallei is very rare; a review of the literature reveals only five previously reported cases. We report the first case of melioidosis infection of a previous femoropopliteal bypass graft complicated by para-anastomotic pseudoaneurysm of the femoral artery successfully treated by surgical removal of the old graft and creation of a new, extraanatomic, external iliac-to-popliteal bypass graft.

Pulmonary artery compression by a saphenous vein graft aneurysm and contrast echocardiography using an agitated mixture of ten percent air, ten percent blood, and ten percent saline

This case illustrates the use of intravenous injection of an agitated mixture of 10% air, 10% blood, and 80% saline during intraoperative transesophageal echocardiography in a patient with a saphenous vein graft aneurysm compressing the main pulmonary artery.

Femoral anastomotic aneurysms: pathogenic factors, clinical presentations and treatment. A study of 142 cases

In this study, the files of 112 patients with a total of 142 femoral anastomotic aneurysms were reviewed. Eighty-five patients (76%) were initially operated upon for obstructive aorto-iliac disease, while the remaining 27 (24%) had abdominal aortic aneurysms repaired. The majority of the patients (104/112) were male and their mean age was 64.5 years (range 45-88). Ninety-three per cent of the subjects were smokers prior to the first operation and 43% continued to smoke at the time of their femoral anastomotic aneurysms operation. The mean delay between the initial surgery and the repair of the femoral anastomotic aneurysms was 74.5 months (range 1-228). The diagnosis was made because of a painless pulsatile mass (91/142), acute leg ischaemia (27/142), a painful pulsatile mass (12/142), haemorrhage (10/142), pseudo-post-phlebitic oedema (1/142) and microemboli of the toes (1/142). The operative mortality was 2.7% (3/112) of which two-thirds were patients with infected grafts. Two subgroups were distinguished: 10 patients with an infected femoral anastomotic aneurysm and 12 patients with recurrent femoral anastomotic aneurysms, 11 with a single recurrence and one with a double recurrence. In the infected group, the time to development of anastomotic aneurysm was shorter than for the group with non-infected femoral anastomotic aneurysms (41 versus 74.5 months) and the operative mortality was 20% (2/10). One patient developed a recurrent femoral anastomotic aneurysm and another was lost to follow-up. Two subsequent deaths occurred, which were unrelated to the femoral anastomotic aneurysms. In the group of recurrent femoral anastomotic aneurysms one patient was lost to follow-up and two patients died, but not as a result of recurrent femoral anastomotic aneurysms. A total of 122 cases underwent interposition of a new prosthetic segment between the proximal prosthesis and the distal artery (89 at the common femoral, 21 at the femoral profundis, eight at the superficial femoral and four at an existing femoro-popliteal graft).

Aortocoronary saphenous vein graft aneurysm in redo coronary artery bypass grafting: report of a case

We report herein the case of an 80-year-old woman who underwent successful redo coronary artery bypass grafting (CABG) for a saphenous vein graft aneurysm found 10 years after her initial operation. On presentation, coronary angiography (CAG) revealed aneurysmal dilatation of the saphenous vein graft and severe stenosis of the left main trunk (LMT). A percutaneous transluminal coronary angioplasty (PTCA) of the LMT lesion was performed; however, a CAG after the PTCA revealed restenosis and the patient developed anginal chest pain at rest. Thus, repeat CABG was urgently carried out, which was followed by a good outcome. Histological examination of the aneurysmal dilatation showed a true aneurysm. Only 15 other cases of redo CABG for this indication have been reported, the features of which are also discussed.

Anastomotic femoral aneurysms: increase in interval between primary operation and aneurysm formation

OBJECTIVE

Anastomotic pseudoaneurysms continue to be a late complication of vascular surgery, particularly following prosthetic graft procedures. The purpose of this study was to investigate if a previously reported increase in interval between the original operation and the development of pseudoaneurysm was still valid.

DESIGN

Retrospective study.

MATERIAL AND METHODS

We reviewed the records of 76 patients who presented with 90 femoral aneurysms. The median age was 69 years (range: 39-83). The commonest previous vascular surgery was a aortofemoral bypass in 61 cases.

RESULTS

The interval between the original operation and the repair of the pseudoaneurysms was 9 years (range 1 month to 26 years).

CONCLUSIONS

This study confirms the previously noted trend of an increasing time to aneurysm formation from 3 years before 1975, 5 years between 1976 and 1980, and 6 years between 1981 and 1990.

Preoperative control of a ruptured anastomotic femoral "pseudoaneurysm" by balloon catheter: a combined radiologic and surgical approach

Inflow control of a rapidly expanding or ruptured femoral anastomotic "pseudoaneurysm" can be fraught with hazard. Occlusion of an anastomotic femoral aneurysm with a balloon catheter offers the surgeon a simple method of gaining inflow control prior to surgery. After achieving inflow control with the balloon catheter, the surgeon can incise the anastomotic aneurysm without significant blood loss, control back bleeding with balloon occlusion catheters, and with relative ease and safety repair or replace the anastomotic aneurysm as indicated. An illustrative case is presented.

Longitudinal forces acting at side-to-end and end-to-side anastomoses when a knitted polyester arterial prosthesis is implanted in the dog

In a previous study, which investigated the tensions at the proximal and distal end-to-end anastomoses of a vascular prosthesis, no significant differences were found in the longitudinal forces between the two anastomotic sites after different periods of implantation. The present follow-up study was devised to study the longitudinal forces at a proximal side-to-end and a distal end-to-side anastomosis using a warp knitted polyester prosthesis implanted as a canine thorocoabdominal bypass. The external surface of the prosthesis contained a specially printed "tension indicator" design, which enabled changes in length to be assessed photographically at the two anastomoses at the time of implantation and at sacrifice. The longitudinal force at each site was then calculated using a relationship obtained experimentally between the total longitudinal force and the changes in length of the virgin graft in vitro. The in vitro measurements on the prosthesis were performed using a computer-controlled laser calibration system. Although the results showed a tendency toward a gradual loss in longitudinal force at both anastomoses over 7 months in situ, statistical analysis showed no significant difference in the longitudinal force at the two anastomotic sites after any period of implantation. Histopathological and textile analysis also showed that the characteristics of the prostheses were similar at both anastomotic sites. This does not mean, however, that the intramural stress concentrations experienced by the two sites were the same. While comparing the level of the longitudinal forces measured in this study with those observed in the previous thoracic aorta study using end-to-end anastomoses, no significant differences were observed due to the different types of anastomoses. It would appear that the longitudinal force is not one of the main etiological factors that cause the formation and localization of anastomotic failure.

Peripheral arterial disease

Peripheral arterial diseases are common problems because atherosclerosis, the most common cause of both occlusive peripheral arterial disease and aneurysmal disease, is a feature of an aging population. The less common types of occlusive peripheral arterial disease--the vasospastic disorders and the arteritides--although frequently not addressed to any extent in medical school curricula or in residency programs in family and internal medicine, offer the alert and informed clinician diagnostic and therapeutic opportunities that are too important to neglect. As a group, abnormalities of the peripheral arteries are easy to detect if careful observation and examination of the extremities is included in the physical examination and attention to functional disorders is included in the medical history. In this presentation, the clinical features, physical findings, complications, useful noninvasive diagnostic tests, imaging techniques, and therapeutic options for atherosclerotic occlusive peripheral arterial disease (both chronic and acute), uncommon types of occlusive arterial disease of both the lower and upper extremities, the vasospastic disorders, and the peripheral arterial presentations of the arteritides are reviewed. The application of natural history and comorbidity of a particular arterial disease, when available, is emphasized in the formulation of management for the individual patient.

False aneurysms after prosthetic reconstructions for aortoiliac obstructive disease

Several aspects of false aneurysm development after prosthetic resconstruction for aortoiliac obstructive disease were studied. For this purpose the long-term results (up to 20 years of follow-up) of 518 patients with implanted arterial prostheses in the aortoiliofemoral tract were retrospectively evaluated. Completeness of follow-up data was 83.2% 15 years after operation. A total of 101 false aneurysms (21 aortic, 53 iliac, and 27 femoral) were detected in 69 patients and verified by operation. The incidence per patient was 69 of 518 patients (13.3%). The incidences per anastomosis were: aortic, 21 of 438 anastomoses (4.8%); iliac, 53 of 835 anastomoses (6.3%); and femoral, 27 of 198 anastomoses (13.6%). Almost one half (47.5%) of all the false aneurysms were asymptomatic and were detected by angiography or ultrasonography. Chances for late survivors to develop a false aneurysm during follow-up were calculated by the life-table method. The chance to be free of a false aneurysm at any site was 77.2% 15 years after operation. These chances were 92.3%, 84.5%, and 76.2% for aortic, iliac, and femoral anastomoses, respectively. Analyses of subgroups showed that the development of a false aneurysm was significantly correlated with the presence of hypertension, multilevel disease, the type of suture material, and the type of anastomosis. These results indicate unexpectedly high chances for the development of false aneurysms in long-term survivors after aortoiliac or aortofemoral prosthetic reconstructions. We advocate the use of a life-long follow-up schedule with periodic angiography and ultrasonography for these patients.

Anastomotic aneurysms of the femoral artery: aetiology and treatment

The aetiology and treatment of 35 femoral false anastomotic aneurysms in 29 patients presenting over the 4-year period 1984-88 were reviewed retrospectively. The mean interval between primary anastomosis and false aneurysm repair was 6 years (range from 2 weeks to 16 years). Twenty-two (63 per cent) false aneurysms had occurred after previous aortobifemoral bypass grafting for occlusive aortoiliac disease. Seven (20 per cent) presented as acute surgical emergencies. Review of the records of the initial operations revealed that superficial wound infections with positive bacteriological cultures had been present in eight cases (23 per cent) and a further two (6 per cent) had lymph fistulae. Thirty-two false aneurysms were repaired, by simple reanastomosis in 14 cases, interposition grafting in 17 cases and in one case by complete revision to an aortobifemoral bypass graft. The risk of a further operative repair was less (P less than 0.05) following interposition grafting, than after simple revision. False aneurysm repairs, when compared with primary reconstructions done during the same period, were associated with more superficial wound infections (37 versus 10 per cent) and more explorations for haemorrhage within 30 days (19 versus 7 per cent).

Anastomotic aneurysms--an underdiagnosed complication after aorto-iliac reconstructions

Anastomotic aneurysms (AA) are recognised as a long-term complication of aorto-iliac (AI) reconstructions and in the literature an incidence of 2-8% is reported. From our own experience we suspected a much higher frequency of this complication and started a follow-up study in order to establish: 1. The actual incidence of AA and 2. The value of various methods of investigation in the diagnosis of this condition. During a 4-year-period (1977-1980) 303 patients (PTS) underwent an AI reconstruction and were the subject of this study. During the mean 8-year (range 6-10 years) follow-up period 158 patients died (52%). The 145 survivors underwent physical examination (PE), ultrasonography (US), and intravenous digital subtraction angiography (i.v. DSA). Complete data were available from 122 patients. The incidence of AA in the 303 patients of the original group, established by routine follow-up examination was 16/303 (5.1%). However, the incidence of AA in the 122 patients in this study was 36/122 (29.5%). These 36 patients developed 52 AA which were located at the following anatomic sites: aortic anastomoses 3/115 (2.6%), iliac artery anastomoses 18/146 (12.3%), femoral artery anastomoses 31/70 (44.3%). Fourteen of the 52 AA (33%) were operated on and the diagnosis was confirmed. The patient characteristics (age distribution, type of arterial reconstruction, indication for operation) of the group of 122 patients were not significantly different from the original group of 303 patients. Intravenous DSA proved to be the most reliable diagnostic test. Physical examination was relatively inaccurate when compared with imaging tests with a 37% false positive and 67% false negative rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Recurrent femoral anastomotic aneurysms. A 30-year experience

Of the 1771 patients who underwent aortofemoral bypass grafting (AFB) during the 30-year period of 1957-1986, 43 noninfected recurrent femoral anastomotic aneurysms (RFAA) developed in 28 patients. Thirty-six RFAAs were treated surgically, with one death and no amputations occurring. Seven small RFAAs (less than 2.0 cm) were treated expectantly without complications. Using univariate and multivariate analyses, clinical characteristics and other factors influencing results in patients with RFAAs were compared to two control groups: patients who had undergone AFB without the development of femoral anastomotic aneurysms (FAAs) and patients who had undergone FAA repairs but without recurrence of FAA. Comparative analyses suggested: 1) local wound complications after initial AFB or FAA repair increased risk of a RFAA (p less than 0.03); 2) development of an FAA within 4.5 years after AFB increased risk of a RFAA (p less than 0.0002); 3) following an FAA repair, risk of a RFAA was almost three times greater for women than for men (p less than 0.05); and 4) patients with arteriosclerotic heart disease (ASHD) were less likely to develop RFAA than those without ASHD (p less than 0.05). Among the 20 additional variables analyzed--including hypertension, smoking, diabetes mellitus, and etiology of primary vascular disease--no statistically significant influence on the development of RFAAs could be detected.

Femoral false aneurysms: a recommendation for the method of repair

False aneurysm formation is a major complication of vascular surgery. The most frequent site of anastomotic false aneurysm formation is the femoral artery. Between January 1974 and June 1986, 26 patients with 42 femoral false aneurysms were treated at the Princess Alexandra Hospital. Aneurysms developed following Dacron arterial grafting (29 aneurysms), saphenous vein grafting (10 aneurysms), umbilical vein grafting (one aneurysm) and femoral embolectomy (two aneurysms). Arterial wall failure (with intact suture and graft) was the most frequent operative finding. Ten recurrent aneurysms developed. There was a significantly greater number of recurrences when resuture or patch repair was employed than when an interposition graft was used as a repair. The development of a femoral anastomotic false aneurysm should be viewed as a total failure of that anastomosis and repair should be by replacement with an interposition graft rather than repair of the failed anastomosis by suture or patch.

Anastomotic aneurysms--an unsolvable problem

Despite the advances in reconstructive vascular surgery anastomotic pseudoaneurysms have remained a serious problem. Even if a faultless operative technique is used this complication cannot always be averted. In order to avoid rupture or thromboembolism and to improve the patient's prognosis we suggest that all pseudoaneurysms are treated surgically except in poor risk patients. Between 1981 and 1986 119 anastomotic aneurysms in 68 patients were operated on in our department. 31.0% presented as infected aneurysms. 13.1% were recurrent after preceding aneurysm repair. The most common site was the femoral region following aortobifemoral bypass. Host vessel degeneration and acute inflammation of the anastomotic site seem to be the most important causative factors. Surgical repair usually consisted of resecting the anastomosis together with part of the host artery; in septic aneurysms limb salvage was attempted using extra-anatomic bypass. Postoperative mortality was 8.8%, minor complications occurred in 10.9%; 9 patients (13.1%) had to have an amputation.

Early detection and differentiation of periprosthetic fluid accumulation after vascular reconstructive surgery

Ultrasonographic duplex scanning is used widely to screen the abdominal arterial system and to detect lesions in the extracranial cerebral arteries. Based on clinical studies of 11,712 vascular reconstructions, this report describes the early recognition of fluid accumulation around vascular prostheses. The clinical examination may suggest the typical complications that arise after vascular surgery such as hematoma, pseudoaneurysm, lymphocele, abscess, or perigraft cyst. Duplex scanning, combined with puncture and aspiration, proved to be of great benefit in differentiating the specific type and extent of the complication. Special attention is paid to the so-called perigraft reaction, thought to be a result of an aseptic biological incompatibility to synthetic vascular grafts. It is emphasized that ultrasonographic routine follow-up after vascular surgery is essential for early diagnosis, especially since each complication suspected requires specific therapeutic treatment to prevent exacerbation because of inadequate treatment.

Femoral anastomotic false aneurysms. An 11-year experience analyzed with a case control study

Eighty-three femoral anastomotic false aneurysms occurring in 51 patients were diagnosed from 1972 through 1982. Twenty-two (27%) presented with acute events. Seventy (84%) were confirmed by sonography and/or arteriography. Bilaterality (29%), recurrence (18%), and associated aortic false aneurysms (8%) were significant problems. Eight-one were repaired with a six per cent complication rate, including one death related to preoperative rupture. The 51 patients were evaluated for associated illnesses, risk factors, and etiologies of their false aneurysms. The most common single cause (61%) was host vessel degeneration with an intact suture line remaining attached to a disrupted Dacron limb. Twenty-three patients with host vessel degeneration were matched with case controls not developing false aneurysms. These two groups were matched for gender, age, and year of AFB and compared for associated illnesses and risk factors. Incidences of cigarette smoking, hypertension, cerebrovascular disease, coronary artery disease, diabetes mellitus, previous femoral endarterectomy, outflow disease, other aneurysmal disease, multiple groin operations, wound complications, and training levels of surgeons performing initial AFBs were similar for both groups. Factors observed significantly more often in patients who developed false aneurysms included serum lipid abnormalities (p less than 0.05), braided synthetic suture material as opposed to monofilament polypropylene (p less than 0.05), and continued abuse of tobacco following AFB (p less than 0.005).

[Anastomotic aneurysms as a late complication of reconstructive vascular surgery of the lower extremity]

29 operations were performed because of an anastomotic aneurysm in 25 patients. The incidence of false aneurysm was 0.7% (4079 reconstructive operations from 1964 to 1979). Arterial reconstructions previous to the formation of aneurysm were: aorto-femoral bifurcation graft 9, ileo-femoral bypass 9, femoro-popliteal reconstructions 11 (4 of them were Sparks' prostheses). 31% of the cases had complications (rupture, thrombosis) when operated, 73% were located in the groin. At the primary operation mostly Dacron had been used. In all instances non-absorbable synthetic suture material has been applied. If the interval between the first operation and the formation of the aneurysms is short infection is to be suspected. The diagnosis of aneurysms distal to the inguinal ligament is easy, aneurysms of the iliac region were found after complications (rupture, thrombosis) had occurred. The most frequent reconstructive procedure was graft interposition, but aneurysmorrhaphy was successful in certain cases. Two patients died postoperatively. Follow-up showed one recurrence (in the groin). We suggest that 1) insufficiency of the suture line because of tension 2) dilation of prosthetic dacron material have great importance for formation of anastomotic aneurysm, whereas local endarterectomy or end-side anastomosis do not seem to be significant.

Recurrence of femoral anastomotic aneurysms

Forty-two noninfected femoral anastomotic aneurysms that occurred after aortobifemoral bypass were repaired during a 7 year period. Twenty of these were recurrent aneurysms. In an attempt to define the cause of recurrence, a number of factors were studied including infection, suture failure, graft deterioration, defective graft manufacture, graft dilatation, and arterial degeneration. Five grafts in the primary group failed because of inherent defects in the graft structure. Two lightweight Dacron grafts showed generalized graft dilatation, and three unwrapped expanded polytetrafluoroethylene grafts had linear tears at the anastomosis. We believe that such graft degeneration does not represent a current problem because the polytetrafluoroethylene grafts now used are reinforced, and lightweight Dacron grafts are no longer made. Two primary femoral anastomotic aneurysms resulted from broken polypropylene suture. No infections were found in the primary or recurrent groups of aneurysms. Arterial degeneration adjacent to the anastomosis, consisting of a decrease in wall thickness due to loss of smooth muscle with proliferation of elastic fibers and disruption of elastic laminae, was a consistent finding in the remaining 15 primary femoral anastomotic aneurysms and all recurrent femoral anastomotic aneurysms. In many instances of primary femoral anastomotic aneurysm and in all instances of recurrent aneurysms dilatation of the Dacron graft with secondary arterial degeneration was believed to be the cause of aneurysm formation. Graft dilatation without fiber deterioration is an inherent problem in Dacron grafts and reportedly varies from 10 to 50 percent of the original graft diameter. This dilatation plus the use of initial graft diameters larger than the host artery leads to increased tension at the anastomotic site with subsequent arterial degeneration. For the aforementioned reasons, our current practice and recommendation is that repair of all anastomotic aneurysms be with expanded polytetrafluoroethylene grafts sized to approximate the host artery since its dilatation at sites of arterial pressure is minimal.