Aortic stent-grafts in patients with renal transplants.

PURPOSE: To report the endovascular treatment of abdominal aortic aneurysms (AAA) in 2 patients with pelvic renal transplants. METHODS AND RESULTS: Two men with multiple comorbidities and pelvic transplant kidneys underwent endovascular AAA repair using an aortomonoiliac system with femorofemoral bypass grafting. The arterial end-to-side anastomosis in both patients was to the external iliac artery. Tapered aortomonoiliac grafts were fashioned from Gianturco Z-stents covered with Dacron graft material and implanted with the distal attachment site in the iliac system ipsilateral to the transplant kidney arterial anastomosis. The body of the stent-graft was reinforcement with a Wallstent in each case before the contralateral common iliac artery was occluded and the cross-femoral bypass constructed. Both patients recovered uneventfully from the procedure and are free of endoleak or other complications related to their aneurysm repair at 7 and 34 months. CONCLUSIONS: The presence of a pelvic renal transplant in a patient undergoing endovascular AAA repair increases the complexity of procedural planning and endograft implantation, but a good outcome can be achieved.

Endovascular repair of abdominal aortic aneurysm: getting out of trouble.

The standard techniques of endovascular aneurysm repair sometimes fail to produce atraumatic stent-graft delivery of hemostatic implantation, and additional maneuvers are required to avoid conversion to open repair. Between June 1996 and May 1997 elective endovascular aneurysm repair was performed in 33 high risk patients, using a Z-stent-based prosthesis. Challenging anatomic features included: short neck (< 15 mm) in four cases, angulated neck (> 60 degrees) in seven, iliac aneurysm in six, and iliac tortuosity (> 80 degrees) in 24. There were no deaths, no renal failure, no pulmonary failure, no graft thrombosis, no migration, and no conversions to open surgery. Deviations from standard technique were required to treat iliac artery dissection, iliac artery stenosis, and leaks resulting from proximal stent malalignment, proximal stent malposition, and distal stent malposition. The necessary adjunctive maneuvers included: additional stent placement, additional stent-graft placement, and balloon dilatation. Mean operating time was 191 +/- 72 min, mean contrast volume was 148 +/- 76 ml, and mean blood loss was 314 +/- 427 ml. Mean time from operation to discharge from the hospital was 3.5 +/- 1.67 days. These short-term results demonstrate that endovascular aneurysm repair is safe and effective in high risk patients, only if adjunctive maneuvers are available to supplement standard technique.

Endovascular aneurysm repair in high-risk patients.

PURPOSE: The purpose of this study was to evaluate the role of endovascular aneurysm repair in high-risk patients. METHODS: The elective endovascular repair of infrarenal aortic aneurysm was performed in 116 high-risk patients with either custom-made or commercial stent grafts. The routine follow-up examination included contrast-enhanced computed tomography (CT) before discharge, at 3, 6, and 12 months, and annually thereafter. Patients with endoleak on the initial CT underwent re-evaluation at 2 weeks. Those patients with positive CT results at 2 weeks underwent endovascular treatment. RESULTS: Endovascular repair was considered feasible in 67% of the patients. The mean age was 75 years, and the mean aneurysm diameter was 6.3 cm. The American Society of Anesthesiologists grade was II in 3.4%, III in 65.5%, IV in 30.1%, and V in 0.9%. There were no conversions to open repair. Custom-made aortomonoiliac stent grafts were implanted in 77.6% of the cases, custom-made aortoaotic stent grafts in 11.2%, and commercial bifurcated stent grafts in 11.2%. The 30-day rates of mortality, major morbidity, and minor morbidity were 3.4%, 20.7%, and 12%, respectively, in the first 58 patients and 0%, 3.4%, and 3.4%, respectively, in the last 58. The late complications included five cases of stent graft kinking, two cases of femorofemoral graft occlusion, and three cases of proximal stent migration, one of which led to aneurysm rupture. At 2 weeks after repair, endoleak was present in 10.3% of the cases. All the type I (direct perigraft) endoleaks underwent successful endovascular treatment, whereas only one type II (collateral) endoleak responded to treatment. The technical success rate at 2 weeks was 86.2%, and the clinical success rate was 96.6%. The continuing success rate was 87.9%. Seventeen patients died late, unrelated deaths. CONCLUSION: Endovascular aneurysm repair is safe and effective in patients at high risk, for whom it may be the preferred method of treatment.

Abdominal aortic aneurysm in high-risk patients: short- to intermediate-term results of endovascular repair.

PURPOSE: To assess the safety and efficacy of endovascular repair of abdominal aortic aneurysm in high-risk patients during the short to intermediate term. MATERIALS AND METHODS: Endovascular aneurysm repair was performed in 50 patients considered too high risk for conventional repair. Stent-grafts were inserted through surgically exposed femoral arteries with fluoroscopic guidance. The anesthetic technique was epidural in 36 patients, general in 12, and local in two. Aortouniiliac stent-grafts were inserted in 42 patients and aortoaortic in eight. RESULTS: There were no deaths and no conversions to open surgical repair. The primary success rate (complete aneurysm exclusion according to CT criteria) was 88% (44 of 50). The secondary, clinical, and continuing success rates were all 98% (49 of 50). Surgical time was 196 minutes +/- 67 (mean +/- SD), blood loss was 284 mL +/- 386, and volume of contrast material administered was 153 mL +/- 64. The time from the end of the surgery to resumption of a normal diet was 0.58 days +/- 0.56, to ambulation was 1.22 days +/- 0.77, and to discharge from the hospital was 3.63 days +/- 1.60. Wound problems accounted for the majority of complications. There were no instances of pulmonary failure, renal failure, stent-graft migration, or late leakage. CONCLUSION: Endovascular repair of abdominal aortic aneurysm is feasible in two-thirds of high-risk patients, with a low mortality and high success rate during the short to intermediate term.

Endoleak after endovascular repair of abdominal aortic aneurysm.

PURPOSE: We sought to assess the role of endovascular techniques in the management of perigraft flow (endoleak) after endovascular repair of an abdominal aortic aneurysm. METHOD: We performed endovascular repair of abdominal aortic aneurysm in 114 patients, using a variety of Gianturco Z-stent-based prostheses. Results were evaluated with contrast-enhanced computed tomography (CT) at 3 days, 3 months, 6 months, 12 months, and every year after the operation. An endoleak that occurred 3 days after operation led to repeat CT scanning at 2 weeks, followed by angiography and attempted endovascular treatment. RESULTS: Endoleak was seen on the first postoperative CT scan in 21 (18%) patients and was still present at 2 weeks in 14 (12%). On the basis of angiographic localization of the inflow, the endoleak was pure type I in 3 cases, pure type II in 9, and mixed-pattern in 2. Of the 5 type I endoleaks, 3 were proximal and 2 were distal. All five resolved after endovascular implantation of additional stent-grafts, stents, and embolization coils. Although inferior mesenteric artery embolization was successful in 6 of 7 cases and lumbar embolization was successful in 4 of 7, only 1 of 11 primary type II endoleaks was shown to be resolved on CT scanning. There were no type III or type IV endoleaks (through the stent-graft). Endoleak was associated with aneurysm dilation two cases. In both cases, the aneurysm diameter stabilized after coil embolization of the inferior mesenteric artery. There were two secondary (delayed) endoleaks; one type I and one type II. The secondary type I endoleak and the associated aneurysm rupture were treated by use of an additional stent-graft. The secondary type II endoleak was not treated. CONCLUSIONS: Type I endoleaks represent a persistent risk of aneurysm rupture and should be treated promptly by endovascular means. Type II leaks are less dangerous and more difficult to treat, but coil embolization of feeding arteries may be warranted when leakage is associated with aneurysm enlargement.

Analysis of initial CT findings after endovascular repair of abdominal aortic aneurysm.

PURPOSE: To determine the spectrum and frequency of specific computed tomographic (CT) findings in the acute period after endovascular repair of abdominal aortic aneurysm (AAA). MATERIALS AND METHODS: CT images obtained 1--3 days after endograft placement were evaluated in 88 patients. The images were analyzed for stent position, appearance of endograft components, perigraft leak, and postoperative findings including air and acute thrombus within the aneurysm and air surrounding the femoral-femoral bypass graft. Findings that could be misinterpreted as perigraft leak were evaluated. RESULTS: Fifteen (17%) of 88 patients had perigraft leak in the acute postoperative period. The bare segment of the proximal self-expanding stent covered one or both renal arteries in 54 (61%) patients. One patient had CT evidence of renovascular compromise. Postoperative air was within the aneurysmal sac in 51 (58%) patients and surrounded the femoral-femoral bypass graft in 67 (94%) of 71 patients in whom the grafts were evaluated with CT. Mottled attenuation within the aneurysmal sac was seen in 50 (57%) patients. Forty-six (52%) patients had calcifications within longstanding thrombus. In 31 (35%) patients, findings that could have been misinterpreted as perigraft leak were identified. CONCLUSION: Accurate analysis of CT findings after endovascular AAA repair requires careful review of all available CT images (preprocedural and pre- and postcontrast) and clear understanding of specific stent-graft components and placement.