Extensible expanded polytetrafluoroethylene vascular grafts for aortoiliac and aortofemoral reconstruction

The operative experience and medium-term outcome achieved with longitudinally extensible ('stretch') expanded polytetrafluoroethylene (ePTFE) bifurcated grafts in patients undergoing aortoiliac or aortofemoral reconstruction for occlusive disease at our institution was reviewed. Between 1991 and 1998, 242 patients received a bifurcated stretch graft. Forty-one patients (17%) required an aortic endarterectomy, and 63 (26%) underwent femoral artery endarterectomy. 228 patients were followed for a mean of 32 months. One patient (0.4%) died perioperatively. The perioperative morbidity included cardiac (3.7%), respiratory (2.5%), and renal (3.3%) complications. Three patients required early reoperation for bleeding. Four (1.7%) grafts thrombosed within 24h of surgery; eight additional grafts (3.3%) thrombosed 5-8 months later. There were three postoperative aortic graft infections, one inguinal infection, three inguinal pseudoaneurysms, and one aortic pseudoaneurysm. Ultrasonography during follow-up showed no periprosthetic fluid collections or graft dilatations. The bifurcated ePTFE stretch graft is suitable for aortoiliac and aortofemoral reconstruction, and its physical characteristics may help to reduce graft-related complications.     

Endovaskuläre Therapie bei aneurysmatischer Allograftdegeneration

Graft infections following aortic vascular procedures are rare, but they are life threatening. Orthotopic vascular restoration with allogenic grafts is a therapeutic option following removal of the infected material. However, graft degeneration is a well-known drawback during follow-up. We present a case of prosthetic infection (bifurcated graft) managed by orthotopic reconstruction with cryopreserved allografts. During follow-up of 27 months without infection, aneurysmal degeneration of the iliac femoral part of the allograft developed. Bilateral endovascular aneurysm exclusion was performed by a homemade device (ePTFE and Palmaz^® stent). According to the results of follow-up, the endovascular approach might become the therapy of choice in cases of aortic allograft degeneration.     

Endovascular treatment of abdominal aortic aneurysms

BACKGROUND: Endovascular treatment of abdominal aortic aneurysms is a rapidly evolving technique that has gained broad acceptance in the treatment of patients with abdominal aortic aneurysms. METHODS: A review of the English literature was done to determine the short- and long-term outcomes of endovascular repair of abdominal aortic aneurysms. Reports of complications such as endoleak, graft migration, graft limb occlusion, aneurysm rupture, and aneurysm enlargement were evaluated. RESULTS: Short-term results of endovascular repair of abdominal aortic aneurysms are excellent. The necessity for open conversions is less than 5%. The cumulative risk of aneurysm rupture is approximately 1% per year. The coverall incidence of graft limb occlusion was 2.8% in the follow-up period. The cumulative risk for a secondary procedure was 12% at 1 year, 24% at 2 years, and 35% at 3 years. Moderate and severe neck angulation was associated with an increased incidence of adverse events in the follow-up period. Endografts have the potential to become infected and develop aortoduodenal fistula. The treatment of ruptured aneurysms with endovascular grafts has been successful and a technique that is increasingly used. CONCLUSION: Endovascular treatment of abdominal aortic aneurysm is an effective technique with excellent short-term results. The long-term results remain to be determined. Ongoing surveillance is necessary to avoid late complications of aneurysm rupture.     

Aneurysmal change at or above the proximal anastomosis after infrarenal aortic grafting.

We conducted a retrospective review of all patients undergoing repair of abdominal aortic aneurysm at or above the proximal anastomosis of a previous infrarenal aortic graft between 1986 and 1991. Infected grafts and patients with suprarenal aneurysms present at the time of the original graft were excluded. Twenty-one patients, 19 men and two women, were included. The original indication for surgery was aneurysm in 14 patients and occlusive disease in seven; the mean interval from initial surgery to presentation was 10 years (range, 3 to 23 years). Twelve lesions were anastomotic false aneurysms, and nine were true aneurysms beginning in the proximal juxta-anastomotic aorta. Fourteen patients had an asymptomatic abdominal mass. Seven patients had symptoms of acute expansion (three), rupture (three), or thrombosis (one). True aneurysm and symptomatic presentation were correlated with aneurysm as the original indication for surgery. Repair was accomplished by an interpositional graft in 13 and graft replacement in eight. Seven patients required suprarenal anastomosis or renal and visceral reconstruction. Five operative deaths (24%) occurred, including two of three patients with rupture (67%) and two of seven patients (28%) in the suprarenal group. The mortality rate for elective repair with an infrarenal anastomosis was 11%. Two additional late deaths occurred during the follow-up period.     

Graft dilatation following abdominal aortic aneurysm resection and grafting

BACKGROUND: It has been suggested that graft dilatation following repair of abdominal aortic aneurysm (AAA) is associated with complications such as anastomotic aneurysm and graft rupture. The purpose of the present study was to document the degree of dilatation observed in grafts after aneurysm repair and to correlate this with any graft-related complications. METHODS: Between January 1987 and December 1992, 219 patients had elective repair of their AAA at St George Hospital. A follow-up ultrasound scan was available for 154 of these patients. The following factors were examined: age, sex, size of aneurysm, type and size of graft, time of follow-up scan, size of graft at follow-up and any graft-related complications. RESULTS: The mean graft dilatation observed in knitted grafts (42.6%; 95% CI: 39.1-46.1%) was significantly greater than that observed for woven grafts (25.5%; 95% CI: 19.0-32.1%; P < 0.0001). There were no graft-related complications. CONCLUSIONS: Graft dilatation is a predictable phenomenon following AAA repair. It is more pronounced in knitted than in woven grafts, but does not necessarily lead to graft-related complications or failure.     

Mid-term results for second-generation thoracic stent grafts

BACKGROUND: Thoracic stent grafts offer an alternative to open surgery for thoracic aortic disease, but their long-term durability is unknown. This report includes mid-term follow-up for commercially available thoracic devices. METHODS: Data were collected prospectively for a series of endoluminal grafts used to treat thoracic aortic pathology. RESULTS: Between July 1997 and October 2002, 67 patients received thoracic stent grafts. Elective procedures incurred a 30-day mortality rate of 2 per cent (one of 42 patients) and urgent repair 16 per cent (four of 25). Paraplegia affected three (4 per cent) of 67 patients and three patients had a stroke. The median follow-up was 17 (range 2-64) months; four patients were lost. There were six late deaths, two from aneurysm rupture (rupture of a mycotic aneurysm at 5 months and stent migration at 28 months). Other device-related complications comprised three proximal endoleaks, one of which required open surgical correction with removal of the stent graft, and two distal endoleaks, which were successfully treated with distal extension cuffs. CONCLUSION: In the mid term, endoluminal repair of thoracic aortic pathology appears to be a safe alternative to open surgery, but continued surveillance is essential.     

True aneurysm formation in axillofemoral bypass with a reinforced ePTFE graft-a case report

Since improvement in reinforced expanded polytetrafluoroethylene (ePTFE) grafts, true aneurysm and pseudoaneurysm formation have become relatively rare complications after axillofemoral reconstruction. This is a case report of a true aneurysm of an axillofemoral graft. The true aneurysm occurred 29 months after insertion of a reinforced ePTFE graft for aortoiliac occlusive disease. A mid-graft true aneurysm was identified during examinations without any trauma history. Continuous long-term follow-up is recommended for these reinforced ePTFE grafts because of rare aneurysm formation, preferably using duplex ultrasonography.     

Long-term results of endovascular abdominal aortic aneurysm treatment with the first generation of commercially available stent grafts

HYPOTHESIS: Little information about the long-term results of endovascular abdominal aortic aneurysm repair is available. This study was performed to evaluate the long-term data of patients treated with the first generation of commercially available stent grafts. DESIGN: Multicenter registry. SETTING: Sixty-two European centers that participated in the EUROSTAR (EUROpean collaborators on Stent-graft Techniques for abdominal aortic Aneurysm Repair) registry. PATIENTS: A total of 1190 patients with a follow-up of up to 8 years, who underwent endovascular abdominal aortic aneurysm repair with a stent graft (Stentor or Vanguard). INTERVENTION: Elective endovascular abdominal aortic aneurysm repair. MAIN OUTCOME MEASURES: The morbidity and mortality data of patients treated with the first-generation stent graft who enrolled in the EUROSTAR registry were analyzed. Incidence rates of complications were calculated to quantify annual risks. Life-table analyses and multivariate Cox proportional hazards models were used for the survival analysis. RESULTS: Conversion to open repair, aneurysm rupture, all-cause death, and aneurysm-related death occurred in 7.1%, 2.4%, 19.9%, and 3.0% of the patients, respectively. The cumulative percentage of the combined outcome event, conversion-free and rupture-free survival, after 8 years was 48.0%. Procedure-related complications that frequently occurred were endoleak (13.0 cases per 100 patient-years), stenosis/thrombosis (4.6 cases per 100 patient-years), and stent migration (4.3 cases per 100 patient-years). CONCLUSIONS: Patients treated with the first generation of stent grafts will need lifelong surveillance because of a considerable risk of late complications. How these findings translate to the outcome of newer-generation stent grafts is unknown. For this reason, vigilant surveillance remains indicated in all patients who undergo endovascular abdominal aortic aneurysm repair.     

Endovascular treatment of the descending thoracic aorta.

OBJECTIVES: to report our initial experience with endovascular stent graft repair of a variety of thoracic aortic pathology. DESIGN: retrospective single center study. MATERIAL AND METHODS: between February 2000 and January 2002, endovascular stent graft repair was performed in 26 patients: traumatic aortic isthmus rupture (n=3), Type B dissection (n=11) and descending thoracic aortic aneurysm (n=12). The deployed stent graft systems were AneuRx-Medtronic (n=1), Talent-Medtronic (n=13) and Excluder-Gore (n=12). RESULTS: successful deployment of the stent grafts in the intended position was achieved in all patients. No hospital mortality neither paraplegia were observed. Late, non procedure related, death occurred in four patients (15%). Access artery complications with rupture of the iliac artery occurred in two patients and were managed by iliac-femoral bypass. The left subclavian artery was overstented in seven patients (27%). Only the first patient received a carotido-subclavian bypass. The mean maximal aortic diameter decreased significantly in patients treated for descending thoracic aneurysm. Only one patient had an endoleak type II after 6 months without enlargement of the aneurysm. Complete thrombosis of the thoracic false lumen occurred in all but one patient treated for Type B dissection 6 months postoperatively. Two patients underwent a consecutive stent graft placement, due to a large re-entry tear distal to the first stent graft. CONCLUSIONS: endovascular stent graft repair for Type B dissection, descending thoracic aneurysm and aortic isthmus rupture is a promising less-invasive alternative to surgical repair. Further studies are mandatory to determine its long-term efficacy.     

Long-term Outcome of Femoral Above-knee Popliteal Artery Bypass Using Autologous Saphenous Vein Versus Expanded Polytetrafluoroethylene Grafts

Despite a recent flurry of publications on preferred techniques for femoral above-knee popliteal artery bypass, controversy persists over the use of autologous saphenous vein and expanded polytetrafluoroethylene (ePTFE) grafts. The purpose of this study was to compare our long-term results using these two bypass materials. In a series of 474 infrainguinal bypasses performed between January 1993 and December 1998, we performed a total of 75 femoral above-knee popliteal artery bypass using an autologous saphenous vein graft in 48 cases (64%) and an ePTFE graft in 27 cases (36%). Prosthetic grafts were used by choice in 17 cases and by necessity due to the absence of useable vein in 10 cases. There were 55 men and 18 women with a mean age of 70 years. The indication for bypass was lower extremity arterial occlusive disease at stage II in 17 cases (22.7%), stage III in 9 cases (12%), and stage IV in 36 cases (48%); subacute ischemia in 8 cases (10.7%); and femoropopliteal aneurysm in 5 cases (6.7%). Preoperative arteriography demonstrated three patent leg arteries in 15.5% of cases, two patent leg arteries in 43.5%, and one patent leg artery in 41%. There was no significance difference between the vein graft and ePTFE graft groups with regard to indications and arteriographic findings. No patient died during the immediate postoperative period. The mean duration of follow-up was 25.5 months (range, 3 to 108 months). The primary patency rate at 4 years was 82.2 ± 8% for venous bypass vs. 80.6 ± 11.8% for ePTFE bypass (p = 0.42). The secondary patency rate at 4 years was 84.7 ± 7.4% for vein bypasses and 79.5 ± 12% for ePTFE bypasses (p = 0.26). In our experience, there was no statistically significant difference in long-term outcome of femoral above-knee popliteal artery bypass using autologous vein grafts or prosthetic ePTFE grafts. Presented at the Seventeenth Annual Meeting of the Société de Chirurgie Vasculaire de Langue Française, May 29-31, 2002, Liege, Belgium.     

Intermediate-term complications and problems after endovascular aortic stent prostheses

From August 1994 to December 1998 321 patients were treated with endovascular stentgrafts for aortic aneurysm exclusion in our hospital. Primary exclusion rate was 91% (primary leakage 8.7%) and hospital mortality was 3.7%. 6 different types of grafts were used, 5 of them commercially available. Midterm complications are due to configuration changes of the grafts, material deterioration, side branch reperfusion and changes in aortic morphology. The common pattern of clinical expression of these complications is secondary leakage (60 cases) and graft limb occlusion (37 occurrences in 30 patients). 50% of the secondary endoleaks have been treated up to now leaving the remaining patients under a thorough follow-up. Graft limb thrombosis was treated in all but three, well compensated, patients. Midterm results of the first commercially available endografts are not yet satisfying in contrast to conventional aortic repair. The recently available grafts are promising as they have a better kink resistance, no graft sutures and fewer modular components.     

Infrainguinal ePTFE vascular graft with bioactive surface heparin bonding. First clinical results

AIM: The ultimate aim of improved expanded polytetrafluoroethylene (ePTFE) vascular graft design is to achieve patency rates in femoropopliteal bypass grafting comparable with autologous saphenous vein grafts. Enhanced thromboresistance of the ePTFE material by bioactive surface heparin bonding is one conceivable path toward this goal. This retrospective study was performed to collect the first clinical data for a new ePTFE graft with bioactive surface heparin immobilization. METHODS: Between March 2003 and February 2004, 43 femoropopliteal or femorocrural ePTFE vascular prostheses with bioactive end-point immobilized heparin (Gore-Tex Propaten Vascular Graft), using the Car-meda BioActive Surface technology, were implanted in 40 patients. Twelve prostheses were implanted in above-knee and 31 in below-knee position. The indication for bypass grafting was limb-threatening ischemia in 88% of the patients. The mean follow-up was 16.6 months. RESULTS: The primary 1-year patency was 91% for above-knee bypass grafts and 92% for below-knee bypass grafts. The 2-year primary patency rate for above-knee bypass grafts was 68% and 81% for below-knee bypass grafts. Limb salvage was achieved in 98%. The perioperative mortality was 0%, but during follow-up 22% of the patients died with patent bypass grafts. CONCLUSIONS: While conventional ePTFE grafts, particularly in the below-knee position, have shown poor results even in the short-term, the bioactive heparinized ePTFE graft evaluated in this study provides patency rates comparable with autologous vein grafts. Because the influence of luminal heparin bonding is not only limited to thromboresistance but has impact on, amongst other elements, protein adsorption (thereby improving hemocompatibility), a continuous effect for long-term patency could also be expected.     

Postoperative dilation of knitted Dacron aortic bifurcation graft

Dilation is the most common inherent "failure mode" of knitted Dacron aortic prostheses. However, the incidence of graft failure related to dilation is unknown because of insufficient data regarding the occurrence, degree, and prognostic significance of postoperative alterations in graft size. In 1979 we reported that postoperative ultrasonic examinations in 95 asymptomatic patients, selected at random after aortic surgery, revealed dilation of the aortic portion of knitted Dacron bifurcation grafts. The average follow-up was 33 months, and the mean dilation was 18%. This article provides the results of a later follow-up, averaging 175 months, in 32 patients from the 1979 study. CT scanning, rather than ultrasonic imaging, was used to evaluate all parts of the grafts. CT scans disclosed that the three parts of each graft dilated, but the parts did not always dilate uniformly. Mean percent dilation values for the entire series were aortic portion 67% +/- 38% SD; right limb 77% +/- 66% SD; left limb 54% +/- 26% SD. Maximum percent dilation for any part of the grafts ranged from 26% to 367% with a mean of 94%. At least one part of the grafts dilated 100% or greater in 12 patients. Three patients had generalized and saccular dilation of the aortic portion of the prostheses and an anastomotic aortic aneurysm; one patient had a localized aneurysm in the midportion of the right limb. Three of the latter grafts were replaced with woven Dacron prostheses.     

Clinical experience with a collagen-impregnated knitted Dacron vascular graft

This report describes our first clinical experience with collagen-impregnated Dacron grafts in the aortic position. Fifty-four consecutive patients (43 men and 11 women), average age 67.5 years (44-84), received 11 tube grafts and 23 bifurcated grafts for abdominal aortic aneurysm replacement, 17 bifurcated grafts for aortic occlusive disease, two grafts for aortic pseudoaneurysm, and one graft for thoracoabdominal aneurysm repair. No preclotting maneuvers were used and there was no blood leak from the fabric upon restoration of blood flow, in spite of the use of systemic heparin. The hospital transfusion rate averaged 1.2 units in patients with occlusive disease and 2.7 units in patients undergoing aneurysm resection, which were similar to the transfusion rate in patients receiving standard knitted grafts prior to this study. There were two postoperative deaths from a myocardial infarction and a cerebral hemorrhage and no perioperative thromboembolic events. During a follow-up averaging 41.5 months (26-59), there were two late graft limb thromboses secondary to outflow disease progression. One patient died of aspiration two months postoperatively. Four patients died secondary to cardiac disease in at 13 and 21 months with functioning grafts. The rest of the patients are alive with functioning grafts. We conclude that the collagen-impregnated Dacron graft obviates the need for preclotting maneuvers because of a zero functional porosity.     

Endovascular Repair of Paraanastomotic Aneurysms after Previous Open Aortic Prosthetic Reconstruction

The aim of this study was to evaluate the effectiveness of endovascular repair of anastomotic and true aortic and iliac aneurysms occurring after prior polyester graft repair for abdominal aortic aneurysms (AAA) or aortoiliac obstructive disease. Between July 1999 and January 2003, 14 patients underwent endovascular treatment of aortic pseudoaneurysms (n = 6) or iliac aneurysms (2 patients with pseudoaneurysms and 6 patients with true aneurysms) occurring 4 to 18.4 years (mean, 8.8 years) after open aortic surgery. No patient had symptoms or positive parameters for infection of the original polyester graft. Eleven patients, including one patient with both a proximal anastomotic and a true iliac aneurysm, were treated with AneuRx (n = 8), Talent (n = 2), or Quantum LP (n = 1) bifurcated stent grafts. Three patients with an infrarenal anastomotic pseudoaneurysm were treated with a tube stent graft (Talent [n = 2] and AneuRx [n = 1]). Endovascular stent grafts were successfully inserted in all patients. Procedure-related complications or death was not seen. During a median follow-up of 12 months (range, 3-40) all anastomotic and/or true aneurysms treated with bifurcated stent grafts maintained excluded. However, two out of three patients, treated with a tube graft for proximal aneurysm exclusion, were converted. In both patients the tube stent graft did not migrate from the level of the renal arteries but fixation failed between the stent graft and the previous polyester graft, creating endotension in the thrombus of the aneurysm sac. In one of these patients the old anastomotic aneurysm ruptured 16 months after stent graft placement and the patient died 1 day after conversion because of mesenterial ischemia. At 1 year follow-up the second patient was converted successfully after enlargement of his anastomotic aneurysm due to similar disconnection between the stent graft and the polyester graft. From this experience with endovascular stent grafts, we conclude that these can be used successfully to exclude anastomotic or true aneurysms after open aortic surgery. Exclusion of aneurysms at the proximal anastomosis with tube stent grafts is apparently not durable because of the insecure distal fixation in polyester grafts. Endovascular repair with bifurcated stent grafts, however, seems to be effective at midterm follow-up.Presented at the Twenty-eighth Annual Meeting of the Peripheral Vascular Surgery Society, Chicago, II, June 7, 2003.     

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. (J Vasc Surg 2000;31:122-33.)     

Management of endoleak after endovascular aneurysm repair: cuffs,coils, and conversion

OBJECTIVE: The effectiveness of endovascular treatment of abdominal aortic aneurysm (AAA) may be limited by persistent perfusion of the aneurysm sac (endoleak). Endoleak that results in persistent systemic pressurization of the aneurysm or in continued AAA expansion is believed to require treatment to prevent rupture. This report describes the results of three techniques used to treat endoleak. METHODS: Endovascular repair of AAA was performed in 597 patients between January 1996 and September 2002. Seventy-three endoleaks that required treatment developed in 70 patients (11.7%). These involved the graft attachment site (type I) or the graft junction site (type III) or originated from collateral side-branch vessels (type II) and were associated with an increase in aneurysm size. Endoleak type was confirmed at angiography in all cases. Average time between the initial endovascular procedure and endoleak treatment was 14.5 +/- 5.7 months. The techniques used for endoleak treatment were deployment of an endovascular extension graft or cuff (n = 44), coil embolization (n = 24,) and conversion to conventional open repair (n = 5). Configurations of endovascular grafts in which endoleak developed were bifurcated (n = 44), aortouniiliac (n = 15), and aortoaortic-tube (n = 11). Mean follow-up after endoleak treatment was 24.5 +/- 12.2 months (range, 1-60 months). RESULTS: Endovascular extension grafts or cuffs were used to treat 41 attachment site endoleaks and 3 graft junction endoleaks, with overall technical success rate of 97%. Embolic coils were used to treat 16 retrograde side-branch endoleaks and 8 attachment site endoleaks, with overall technical success rate of 87%. Conversion to open surgery was performed in 4 patients with attachment site endoleaks and 1 patient with a graft junction site endoleak, and was successful in all cases. After endoleak treatment, aneurysm size decreased (>5 mm) in 38% of patients, stabilized in 58% of patients, and increased (>5 mm) in 4% of patients. Major morbidity occurred in 7.0%, with no perioperative deaths. CONCLUSIONS: Endovascular extension grafts, coil embolization, and conversion to open surgery each may be used to effectively repair endoleak. Selection of the treatment method used is determined by the anatomic characteristics of the endoleak and the patient's ability to tolerate conventional repair. Conversion to open repair was uniformly successful. Deployment of an extension cuff was successful when complete closure of the endoleak was achieved. Embolic coils were effective for retrograde endoleaks and provided stabilization of AAA size in selected patients with attachment site endoleaks in limited follow-up.     

Use of hybrid aortic stent grafts for endovascular repair of abdominal aortic aneurysms: indications and outcomes

BACKGROUND: Only two aortic stent grafts (Ancure-Guidant, Menlo Park, CA, and AneuRx-Medtronic, Sunnyvale, CA) have been FDA-approved for endovascular aortic aneurysm repair (EndoAAA). These grafts differ significantly in construction and clinical advantage, and combining components of these grafts (hybrid graft) is occasionally necessary. The role and outcome of hybrid aortic stent grafts is unknown. METHODS: All EndoAAA procedures during an 18-month period (10/99-4/01) were reviewed using the hospital record and a computer registry. Endografts were classified as hybrid if components from more than one type of stent graft were used or standard if constructed from only one stent graft type. Hybrid grafts were further classified as "anticipated" or "unanticpated." Outcomes were compared between hybrid and standard grafts using Fisher's exact test. RESULTS: One hundred forty-five EndoAAA repairs were performed (AneuRx, 67; Ancure, 70; and custom-made, 8) of which 14 (9.6%) were hybrid grafts. The majority of hybrid grafts (11) were constructed by adding AneuRx aortic or iliac cuffs to Ancure grafts. In most cases, the need for a hybrid graft was unanticipated (10) and related to an intraoperative proximal type I endoleak (7). Conversion to open operation was avoided in six patients by constructing hybrid grafts. When anticipated (4), hybrid grafts were constructed to treat complex iliac aneurysms. Outcomes in all categories were similar (P > 0.05) for hybrid vs standard grafts: technical success (93 vs 99%), conversion toopen AAA (7.1 vs 2.3%), vascular complications (7.1 vs 7.6%), systemic complications (21 vs 11%), endoleak (15 vs 14%), and rupture (0 vs 0%). CONCLUSIONS: The short-term safety and effectiveness of hybrid grafts are similar to those of standard grafts. Combining graft components to create hybrid grafts may increase the ability to treat complex iliac aneurysmal disease and may reduce conversions to open AAA repair. Thus, access to multiple graft types may be an important factor in the success and safety of EndoAAA repair.     

Challenges of hemodialysis access for high risk patients: Impact of mesenteric vein bioprosthetic graft

Objective: The purpose of this study is to compare in a prospective fashion the performance of a new bioprosthesis, the mesenteric vein bioprosthesis (MVB), in patients who have had multiple failed ePTFE grafts. Performance measures include primary patency rates, assisted-primary patency rates, secondary patency rates, complications, and the number of interventions required to maintain graft patency. Study: From October 1999 to February 2002, 276 hemodialysis access grafts were implanted in a multicenter study. Of those grafts, 74 were placed in patients with a prior history of 3 failed prosthetic grafts (mean = 3.5 grafts, range = 3-6 grafts). Fifty-nine grafts were constructed with MVB, and 15 grafts with ePTFE as a concomitant control. Mean follow-up was 11.5 months. In the MVB group, 79.7% were African-Americans, 61% were females, and 23.7% were hypercoagulable. Of the ePTFE group, 86.7% were African-Americans, 46.7% were female, and 13.2% were hypercoagulable. Results : Per Kaplan-Meier curves, the primary patency rate of the MVB group at 12 months was 33% vs the ePTFE group of 18% (p=0.120); the assisted-primary patency rates at 12 months were 45% MVB vs 18% ePTFE (p=0.011). The secondary patency rates at 12 and 24 months for the MVB group were 67% and 59%, respectively, vs 45% and 15% for the ePTFE group (p=0.006). During the follow-up time period, 80% of the ePTFE grafts were abandoned compared to 34% of the MVB group. Infection and thrombosis rates in the MVB group were lower than the ePTFE group. The infection rate for the MVB group requiring intervention was 0.07 events/graft year (gt/y) compared to 0.30 events/gt-y for ePTFE (p=0.04). A thrombosis rate of 0.69 events/gt-y occurred in the MVB group whereas 2.50 events/gt-y presented in the ePTFE group (p<0.01). Conclusion: In this study, high-risk patients (defined as those having multiple failed prosthetic grafts for hemodialysis) in whom the MVB conduit for hemoaccess was implanted, showed significant improvement in assisted-primary and secondary patency rates compared to the ePTFE cohort. The MVB group, however, did not have a statistically better primary patency rate compared to the ePTFE group. The MVB patient also had fewer thrombotic and infectious events and an overall reduction in the number of interventions while maintaining a permanent access site. This new bioprosthesis should be the conduit of choice in the complex group of patients as it offers assisted-primary and secondary patency rates similar to those commonly experienced by patients without a history of multiple graft failures.     

Long-term outcome after treatment of aortic graft infection with staged extra-anatomic bypass grafting and aortic graft removal

OBJECTIVE: The purpose of this study was to determine long-term outcome in patients with infected prosthetic aortic grafts who were treated with extra-anatomic bypass grafting and aortic graft removal. METHODS: Between January 1989 and July 1999, 36 patients were treated for aortic graft infection with extra-anatomic bypass grafting and aortic graft removal. Extra-anatomic bypass graft types were axillofemoral femoral (5), axillofemoral (26; bilateral in 20), axillopopliteal (3; bilateral in 1) and axillofemoral/axillopopliteal (2). The mean follow-up was 32.3 +/- 4. 8 months. RESULTS: Four patients (11%) died in the postoperative period, and two patients died during follow-up as a direct consequence of extra-anatomic bypass grafting and aortic graft removal (one died 7 months after extra-anatomic bypass graft failure, one died 36 months after aortic stump disruption). One additional patient died 72 months after failure of a subsequent aortic reconstruction, so that the overall treatment-related mortality was 19%, whereas overall survival by means of life table analysis was 56% at 5 years. No amputations were required in the postoperative period, but four patients (11%) required amputation during follow-up. Twelve patients (35%) had extra-anatomic bypass graft failure during follow-up, and six patients underwent secondary aortic reconstruction (thoracobifemoral [2], iliofemoral [2], femorofemoral [2]). However, with the exclusion of patients undergoing axillopopliteal grafts (primary patency 0% at 7 months), only seven patients (25%) had extra-anatomic bypass graft failure, and only two patients required amputation (one after extra-anatomic bypass graft removal for infection, one after failure of a secondary aortic reconstruction). Furthermore, primary and secondary patency rates by means of life table analysis were 75% and 100% at 41 months for axillofemoral femoral grafts and 64% and 100% at 60 months for axillofemoral grafts. Only one patient required extra-anatomic bypass graft removal for recurrent infection, and only one late aortic stump disruption occurred. CONCLUSIONS: Staged extra-anatomic bypass grafting (with axillofemoral bypass graft) and aortic graft removal for treatment of aortic graft infection are associated with acceptable early and long-term outcomes and should remain a primary approach in selected patients with this grave problem.