Five-year experience with endovascular grafts for the treatment of aneurysmal, occlusive and traumatic arterial lesions

Endovascular Reconstruction for Chronic Infrarenal Aortoiliac Occlusive Disease

According to the 2007 TransAtlantic Inter-Society Consensus (TASC II) guidelines, surgery is the preferred treatment for extensive (TASC II type C and D) aortoiliac occlusive disease (AIOD). Recent studies, however, have shown that endovascular management can be an effective first-line treatment option for TASC II type C and D categories. While endovascular therapy is now commonly performed in patients with TASC II type D lesions, very few studies have investigated the feasibility and effectiveness of extending endovascular therapy to the most severe subcategory of TASC II D lesions, chronic infrarenal aortoiliac occlusion (CIAO). Herein, we present our technique for endovascular treatment of CIAO which relies on bidirectional subintimal aortoiliac dissection, wire snare for true lumen reentry, and combined balloon-expandable and self-expanding covered stent reconstruction of the aortic bifurcation and bilateral iliac arteries. This technique safely extends the reach of endovascular therapy to the most severe subcategory of TASC II D AIOD, CIAO. It is a viable minimally invasive alternative to aortobifemoral bypass surgery. Long-term follow-up of larger cohorts is needed to verify clinical efficacy and durability of therapy.

A comparison of covered vs bare expandable stents for the treatment of aortoiliac occlusive disease

OBJECTIVE

This trial was conducted to determine if covered stents offer a patency advantage over bare-metal stents in the treatment of aortoiliac arterial occlusive disease.

METHODS

The Covered Versus Balloon Expandable Stent Trial (COBEST), a prospective, multicenter, randomized controlled trial, was performed involving 168 iliac arteries in 125 patients with severe aortoiliac occlusive disease who were randomly assigned to receive a covered balloon-expandable stent or bare-metal stent. Patient demographic data, clinical signs and symptoms, TransAtlantic Inter-Society Consensus (TASC) classification, and preprocedure and postprocedure ankle-brachial index measurements were recorded. The primary end points included freedom from binary restenosis and stent occlusion of the treated area, as determined by ultrasound imaging or quantitative visual angiography, or both. Postprocedural follow-up was at 1, 6, 12, and 18 months.

RESULTS

Aortoiliac lesions treated with a covered stent were significantly more likely to remain free from binary restenosis than those that were treated with a bare-metal stent (hazard ratio [HR], 0.35; 95% confidence interval (CI), 0.15-0.82; P = .02). Freedom from occlusion was also higher in lesions treated with covered stents than in those treated with a bare-metal stent (HR, 0.28; 95% CI, 0.07-1.09); however, this did not reach statistical significance (P = .07). Subgroup analyses demonstrated a significant difference in freedom from binary restenosis for covered stents in TASC C and D lesions compared with a bare stent (HR, 0.136; 95% CI, 0.042-0.442). This difference was not demonstrated for TASC B lesions (HR, 0.748; 95% CI, 0.235-2.386).

CONCLUSIONS

COBEST demonstrates covered and bare-metal stents produce similar and acceptable results for TASC B lesions. However, covered stents perform better for TASC C and D lesions than bare stents in longer-term patency and clinical outcome.

Traumatic superior mesenteric arteriovenous fistula and aortic pseudoaneurysm 20 years after repair

A case of traumatic superior mesenteric arteriovenous fistula (SMAVF) and aortic pseudoaneurysm successfully treated by a unique combination of operative and endovascular techniques with a 20-year follow-up is reviewed. After 20 years, the patient presented with an aortoenteric fistula, which was managed with a cryopreserved aortic interposition graft. In this report, we review the evolution of the treatment for traumatic SMAVF and aortic pseudoaneurysm and the current management of aortoenteric fistula.

1992: Parodi, Montefiore, and the First Abdominal Aortic Aneurysm Stent Graft in the United States

In 1990 Juan C. Parodi performed the first endovascular abdominal aortic aneurysm (AAA) repair in Buenos Aires. Two years later, in 1992, Parodi and Claudio Schonholz visited Montefiore Medical Center in New York to perform with us the first endovascular AAA repair to be done in the United States. Since then the Montefiore/Einstein vascular group has performed 1522 endovascular grafts in 674 patients for many types of vascular lesions using a variety of both surgeon-made and industry-made devices. The purpose of the present article is to describe the events that surrounded the performance of the first seminal endovascular AAA repair at our institution on November 23, 1992.

Optimal follow-up strategies after aorto-iliac prosthetic reconstruction: a decision analysis and cost-effectiveness analysis

OBJECTIVE

The primary aim of ultrasound follow-up after aorto-iliac prosthetic reconstruction is to correct false aneurysms before rupture occurs. We investigated whether follow-up improves the life expectancy of patients and sought to identify the most cost-effective follow-up strategy.

DESIGN OF THE STUDY

A Monte Carlo Markov decision model was constructed. The occurrence of false aneurysms was modelled as a time-dependent process for each anastomotic site, based on published series. Using this model, the impact of various follow-up strategies was investigated for three types of prostheses, aorto-distal tube, aorto-bi-iliac, and aorto-bi-femoral prostheses. Main outcome measures were discounted quality adjusted life years (dQALYs), discounted costs, and (discounted) cost-effectiveness (CE) ratios.

RESULTS

Follow-up of patients with aorto-distal tube and aorto-bifemoral prostheses did not result in an improvement life expectancy and was not cost-effective, QALYs 7.53 and 7.62 years, respectively. The results for aorto-distal tube and aorto-bifemoral prostheses were not sensitive to any variation in the model parameters. In the base case analysis, the life expectancy of patients with aorto-bi-iliac prostheses was 7.50 QALYs (95% confidence interval 7.46-7.54) whether or not they underwent routine follow-up. However, patients aged 54 years or younger gained 0.11 QALYs with annual follow-up (p<0.05). The most cost-effective strategy was annual follow-up that starts 10 years after the initial operation, and continues up to 30 years after surgery (4600 Euro; CE ratio 21,000 Euro per QALY). When perioperative mortality of elective reconstruction of false aneurysms is 2% or lower (e.g. when endovascular treatment is used), a small improvement is observed (7.56 vs. 7.50 QALYs; p<0.05; CE ratio 35,000 Euro per QALY).

CONCLUSIONS

Annual follow-up of aorto-bi-iliac prostheses should be restricted to patients aged 54 or younger and not start before 10 years after surgery. The same strategy can only be considered for older patients if mortality for secondary intervention is lower than 2%. Since patients with aorto-distal tube and aorto-bi-femoral prostheses do not benefit from follow-up for the detection of false aneurysms, this practice should be discouraged in these patient groups.

Delayed open conversion following endovascular aortoiliac aneurysm repair: partial (or complete) endograft preservation as a useful adjunct

OBJECTIVES

The purpose of this study was to review our experience with delayed open conversion (>30 days) following endovascular aortoiliac aneurysm repair (EVAR) and to introduce the concept and advantages of endograft retention in this setting.

METHODS

From January 1992 to January 2003, a total of 386 EVARs using a variety of endografts were successfully deployed. Eleven (2.8%) patients required delayed conversion to open repair at an average of 30 months (range, 10-64). Data from all patients undergoing both EVAR and open conversion were prospectively collected.

RESULTS

EVARs were performed using grafts made by Talent (4), Vanguard (2,) AneuRx (1), and Surgeon (4). Conversion to open repair (9 transabdominal, 1 retroperitoneal, 1 transabdominal plus thoracotomy) was performed for aneurysm rupture in 7 patients (4 type 1 endoleak, 2 type 2 endoleak, 1 aortoenteric fistula) and aneurysm enlargement in 4 patients (1 type 1 endoleak, 1 type 2 endoleak, 1 type 3 endoleak, 1 endotension). Patients with aneurysm rupture were treated on an emergent basis. Complete removal of the endograft with supraceliac cross-clamping was performed in two cases. One patient (rupture) did not survive the operation, and one patient (aortoenteric fistula) died 2 weeks postoperatively. In the remaining nine cases, the endograft was either completely (1) or partially (6) removed, or left in situ (2). Supraceliac balloon control (2), supraceliac clamping (1), suprarenal clamping (1), or infrarenal clamping (5) was used in these cases. All nine of these patients survived the operation. In one procedure in which the endograft was left intact (endotension), repair was accomplished by exposing the endograft and by placing a standard tube graft over it as a sleeve. In the second procedure in which the graft was left in situ (rupture), the graft was well incorporated, and bleeding lumbar arteries were oversewn and the sac was closed tightly over the endograft. In the remaining 7 cases, the endograft was transected and the proximal portion only (6) or the proximal and distal portions (1) were excised. All surviving patients continue to do well and remain without complications associated with the endograft remnant at a mean follow-up of 22 months (range, 3-56) from the time of open conversion and 46 months (range, 10-73) from the time of original EVAR.

CONCLUSIONS

Open repair in the setting of a long-standing endograft offers several unique technical challenges but can be successfully accomplished in most patients. Preservation of all or part of the endograft is possible in many patients. This technique simplifies the operative approach and is preferred over complete endograft removal if possible.

Endovascular stent grafting of descending thoracic aortic aneurysms

The treatment of descending thoracic aortic aneurysms using endovascular stents is one of the more recent advances in treatment and is receiving increasing attention as it is a less invasive alternative to open surgical repair. Although the technology is still primitive, significant improvements have lately been made in the design and deployment of the endovascular stent-grafts. Aortic stent-grafts were used initially to exclude abdominal, and later thoracic, aortic true and false aneurysms. These prostheses have been increasingly used to treat aneurysms, dissections, and traumatic ruptures of the descending thoracic aorta with good early and mid-term outcomes. Although the long-term outcome of patients with aneurysms of the descending thoracic aorta after stent graft implantation has not been investigated, continued refinement of the endovascular approaches has decreased the need for conventional open thoracic aortic aneurysm repair, especially in patients who are at a high risk for standard surgery because of advanced age or the presence of comorbid diseases. The placement of endoluminal stent-grafts to exclude the dissected or ruptured site of thoracic aortic aneurysms is a technically feasible and relatively safe procedure. With the rapid development of endovascular approaches, the treatment of the descending thoracic aortic aneurysms might alter even more, but an extended follow-up is necessary to determine the longer term outcome. Historical perspectives, advantages, device considerations, complications, and current perspectives of the endovascular stent grafting of the descending thoracic aortic aneurysms are elaborated on.

Overt colon ischemia after endovascular aneurysm repair: the importance of microembolization as an etiology

OBJECTIVE

The purpose of this study was to analyze the incidence, severity, and etiologic factors of the development of colon ischemia after endovascular aortoiliac aneurysm repair (EVAR).

METHODS

During the last 9 years we performed 278 elective EVARs using a variety of grafts. To facilitate these repairs, one hypogastric artery (HA) was coil embolized in 109 patients and both HAs were coil embolized in 13 patients. The preprocedural status of the inferior mesenteric, hypogastric, and iliac arteries as well as anatomical characteristics of the abdominal aortic aneurysm were determined arteriographically and by computerized tomographic scans. Postoperative colon ischemia was documented by colonoscopy or operative findings.

RESULTS

Colon ischemia occurred in eight patients (2.9%). Three patients with colon ischemia died and had evidence of widespread (cutaneous, renal, small bowel, and/or lower extremity) microembolization. One of these three had a colectomy and microscopic emboli were present. One other patient who required a colectomy also had pathologic evidence of colonic microembolization but survived. Four other patients with colon ischemia were treated conservatively and survived. In one patient, previous colectomy with interruption of mesenteric collaterals may have been a contributory cause of colon ischemia. Of the eight patients with colon ischemia, only one had unilateral HA occlusion, and none had bilateral HA occlusion. The other 121 patients with unilateral and bilateral HA occlusion had no evidence of colon ischemia.

CONCLUSIONS

Colon ischemia occurs after EVAR with an incidence approximating that of open repair. Colon ischemia was unrelated to HA interruption. Embolization appears to be a major cause of colon ischemia, although inadequate mesenteric collateral circulation may also play an etiologic role. Mortality with colon ischemia accompanied by widespread embolization was high, whereas colon ischemia without it was often mild and amenable to nonoperative management.

Increasing incidence of midterm and long-term complications after endovascular graft repair of abdominal aortic aneurysms: a note of caution based on a 9-year experience

OBJECTIVE

To analyze the late complications after endovascular graft repair of elective abdominal aortic aneurysms (AAAs) at the authors' institution since November 1992.

SUMMARY BACKGROUND DATA

Recently, the use of endovascular grafts for the treatment of AAAs has increased dramatically. However, there is little midterm or long-term proof of their efficacy.

METHODS

During the past 9 years, 239 endovascular graft repairs were performed for nonruptured AAAs, many (86%) in high-risk patients or in those with complex anatomy. The grafts used were Montefiore (n = 97), Ancure/EVT (n = 14), Vanguard (n = 16), Talent (n = 47), Excluder (n = 20), AneuRx (n = 29), and Zenith (n = 16). All but the AneuRx and Ancure repairs were performed as part of a U.S. phase 1 or phase 2 clinical trial under a Food and Drug Administration investigational device exemption. Procedural outcomes and follow-up results were prospectively recorded.

RESULTS

The major complication and death rates within 30 days of endovascular graft repair were 17.6% and 8.5%, respectively. The technical success rate with complete AAA exclusion was 88.7%. During follow-up to 75 months (mean +/- standard deviation, 15.7 +/- 6.3 months), 53 patients (22%) died of unrelated causes. Two AAAs treated with endovascular grafts ruptured and were surgically repaired, with one death. Other late complications included type 1 endoleak (n = 7), aortoduodenal fistula (n = 2), graft thrombosis/stenosis (n = 7), limb separation or fabric tear with a subsequent type 3 endoleak (n = 1), and a persistent type 2 endoleak (n = 13). Secondary intervention or surgery was required in 23 patients (10%). These included deployment of a second graft (n = 4), open AAA repair (n = 5), coil embolization (n = 6), extraanatomic bypass (n = 4), and stent placement (n = 3).

CONCLUSION

With longer follow-up, complications occurred with increasing frequency. Although most could be managed with some form of endovascular reintervention, some complications resulted in a high death rate. Although endovascular graft repair is less invasive and sometimes effective in the long term, it is often not a definitive procedure. These findings mandate long-term surveillance and prospective studies to prove the effectiveness of endovascular graft repair.

Endovascular stent-graft repair of primary aortocaval fistula with an abdominal aortoiliac aneurysm

A primary aortocaval fistula is present in less than 1% of all abdominal aortic aneurysms. Until recently, surgical repair was the only method of treatment and was associated with a high incidence of morbidity and mortality. With the rapid development of aortic stent-graft technique, endovascular stent-graft repair may offer an alternative to the management of this often fatal condition. We report a case of an aortoiliac aneurysm with an aortocaval fistula successfully treated with endovascular stent-grafting. The unique hemodynamic changes, technical problems, and complications associated with this case are discussed, and the literature is reviewed.

Endovascular Treatment of Aortic Disease

A review is given of endovascular treatment for AAA, thoracic aortic aneurysms, dissections as well as complications following previous aortic surgery. In several of these conditions endovascular treatment has advantages like a reduced operative trauma, shorter stay in hospital, and the possibility of treating patients who would have been unfit for open surgery. On the other hand, problems like endoleak, deformation of the endoprosthesis, retrograde filling of the aneurysmal sack, and graft limb occlusion need to be solved before the place of endovascular treatment can be defined. It is possible that the steadily improving quality of the implants as well as the introducer systems will widen the indications for endovascular surgery, but randomised clinical trials are warranted and a longer follow-up period is necessary to draw final conclusions.

Abdominal Aortic Aneurysms

The mortality rate after the rupture of an abdominal aortic aneurysm is 80% to 90%; therefore, the main goal of treatment is to prevent rupture. Patients with abdominal aortic aneurysms smaller than 5 cm in diameter should be managed conservatively under close surveillance with either computed tomography or sonography every 3 to 12 months. Patients should be informed that most aneurysms continue to enlarge at an average rate of 2 to 4 mm per year and that there is a 1% to 5% annual risk for sudden rupture. Treatment of the aneurysm is generally recommended if it is larger than 5 cm in diameter, and the only effective treatment is replacement of the aneurysm with a prosthetic graft. This can be performed through a laparotomy or a groin incision using an endovascular graft. Open surgical repair carries a mortality rate of 2% to 8% and requires a hospital stay of 7 to 10 days. Patients receiving endovascular grafts can be discharged within 1 to 3 days. Long-term durability has yet to be proven, however.