Endovascular treatment of iliac limb stenoses or occlusions in 31 patients treated with the ancure endograft

Incidence and predictive factors for endograft limb patency of the Fenestrated Anaconda™ endograft used for complex endovascular aneurysm repair

OBJECTIVE

To describe the incidence, risk factors and outcomes of treatment for limb occlusion in patients treated for complex (thoraco-)abdominal aortic aneurysms (AAA) with the Fenestrated Anaconda™.

METHODS

Between June 2010 and May 2018, 335 patients underwent elective fenestrated aortic aneurysm repair in 11 participating centers using the Fenestrated Anaconda™ with a median follow-up of 14.3 months (IQR 27.4). The primary outcome measure was freedom-from-limb-occlusion. Secondary outcome measures were freedom-from-limb-related-reintervention, secondary patency, and risk factors associated with limb occlusion.

RESULTS

Thirty (9.0%) patients presented with limb occlusion during follow-up with freedom-from-limb-occlusion of 98.5%, 91.2%, and 81.7% at 30-days, 1 and 5 years, respectively. In 87% of cases, no obvious cause for limb occlusion was documented. Primary occlusion occurred within 30-days in 36.7% and within 1 year in 80.0%. Twenty-three (6.9%) patients underwent an occlusion-related reintervention; seven (23.3%) patients were treated conservatively. Freedom-from-limb-occlusion-related-reintervention at 30-days, one and five years was 97.8%, 93.2% and 88.6%, respectively. Secondary patency was 91.3% after 1-month and 86.2% after 1 and 5 years, respectively. Female sex (OR 3.27 - 95% CI 1.28 to 8.34, P = .01) was a statistically significant predictor for limb occlusion. A higher percentage of thrombus in the aneurysm sac appeared to be protective for limb occlusion (0% compared to <25%: OR 0.22 - 95% CI 0.07 to 0.63, P = .01; 0% compared to 25-50%: OR 0.20 - 95% CI 0.07 to 0.57, P = .00 and 0% compared to >50%: OR 0.08 - 95% CI 0.02 to 0.38, P = .00), as did iliac angulation (OR 0.99 - 95% CI 0.98 to 1.00, P = .04).

CONCLUSION

Limb occlusion remains a significant impediment of endograft durability in patients treated with the Fenestrated Anaconda™, especially in female patients. Controversially, a high aneurysmal thrombus load and a high degree of iliac angulation appeared to be protective for limb occlusion, for which no obvious cause could be identified.

The impact of combined iliac occlusive disease and aortic aneurysm on open surgical repair

OBJECTIVE

Severe aortoiliac occlusive disease is a relative contraindication for endovascular aneurysm repair, owing to an association with high stent graft-related complication and reintervention rates in this population. Open AAA repair requiring aortofemoral bypass (AFB), however, may represent a unique population with differing outcomes from standard open repair. We sought to compare the demographic and procedural characteristics, as well as outcomes of patients undergoing standard intra-abdominal repairs (STD) versus those requiring AFB.

METHODS

Using a prospectively maintained database, we retrospectively identified patients who underwent open AAA repair from 1994 to 2017. A total of 1087 consecutive cases were performed consisting of 981 STD (681 tube graft, 300 aortoiliac) and 106 AFB cases. Demographics, procedural data, postoperative complications, and long-term survival were analyzed.

RESULTS

The AFB cohort had more women (39.0 vs 22.8%; P = .001) and higher rates of hypertension (81.1 vs 69.8%; P = .015), chronic obstructive pulmonary disease (28.3 vs 17.4%; P = .006), and smoking (50.9 vs 36%; P = .002). The AFB group had smaller mean aortic (5.22 vs 5.77 cm; P = .001) and graft (17.08 vs 18.2 mm; P = .001) diameters. Proximal clamp position and blood loss were equivalent, although total anesthesia time was longer (295 vs 234 minutes; P = .001) in the AFB cohort. Overall 30-day postoperative morbidity (38.7 vs 24.8%; P = .002) was higher in the AFB group. Specifically, postoperative renal insufficiency (8.2 vs 3.4%; P = .032), wound infection (5.7 vs 1.2%; P = .005), and hematoma/seroma (5.7 vs 1.2%; P = .003) were more likely. Hospital length of stay was longer for AFB (11.9 vs 9.9 days; P = .007). The 30-day mortality (0.9% AFB vs 1.8% STD; P = .50) and major morbidity (17 vs 11.5%; P = .10) did not differ. Reintervention rate within 30 days of the initial surgery (12.3 vs 4.6; P = .001) and overall (33 vs 18.9%; P = .001) was higher in the AFB group. Long-term survival was lower in the AFB group (5-year survival: 63.1% AFB vs 71.9% STD; hazard ratio 0.76, log-rank P = .047). Multivariate regression analysis identified age, comorbid conditions, and aneurysm characteristics-rather than repair type-as independent predictors of 30-day reintervention and mortality at 5 years.

CONCLUSIONS

Patients requiring AFB for AAA owing to associated iliac occlusive disease have more preoperative comorbidities, postoperative complications, a longer length of stay, reintervention rates and shorter 5-year survival. Patient and aneurysm characteristics rather than surgical repair type appear to be responsible for these differences. Nevertheless, 30-day mortality and major morbidity were comparable, making AFB an attractive alternative to endovascular aneurysm repair in patients with advanced iliac occlusive disease.

Clinical and anatomical variables associated in the literature to limb graft occlusion after endovascular aneurysm repair compared to the experience of a tertiary referral center

INTRODUCTION

Limb graft occlusion (LGO) is the third reason for hospital readmission after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm. We reviewed the clinical features, incidence, anatomical and devices related predictive factors for LGO after EVAR, and compared them with our experience.

EVIDENCE ACQUISITION

EVAR between 2010-2017 were included. Patients with LGO (LGO group) were matched for age and type of endograft with the rest of the entire cohort without LGO (control group). Clinical, anatomical, operative, outcome, and follow-up data were collected.

EVIDENCE SYNTHESIS

Two hundred seventy-six EVAR, (30 aorto-uniliac), 276 patients. The incidence of LGO was 2.5% (seven limbs, seven patients) at 27±24.6 days. Symptomatic patients were successfully treated. No mortality, limb loss, critical limb ischemia or residual claudication due to LGO was observed. Fifty patients resulted from the matching. Among the predictive factors of LGO between the two groups, significant differences were observed in graft limb oversizing ≥15% (57.1% vs. 8%, P=0.005), or kinking (42.9% vs. 2%, P=0.01), and diameter of the aortic bifurcation <20 mm (71.4% vs. 20%, P=0.01). Logistic regression analysis showed that these three variables increased the risk of LGO (P=0.003, P=0.006, and P=0.01, respectively).

CONCLUSIONS

The strongest predictive factors of LGO issued from our review were: extension in the external iliac artery, or small diameter; tortuous, angled, and calcific iliac axis; excessive oversizing of the limb graft, or kinking; use of old generation devices; EVAR performed outside the instructions for use. Limb graft oversizing >15%, or kinking, and aortic bifurcation <20 mm appear to be independent predictive factors of LGO.

Contemporary imaging methods for the follow-up after endovascular abdominal aneurysm repair: a review

Abdominal aortic aneurysm (AAA) is defined as a localized enlargement of the aortic cross-section where the diameter is greater than 3 cm or more than 50% larger than the diameter in a normal segment. The most important complication of AAA is rupture, which, if untreated, results in mortality rates of up to 90%. Conventional open surgical repair is associated with significant 30-day mortality. Endovascular aneurysm repair (EVAR) is a significantly less invasive procedure; it is related to a lower early mortality rate and a lower number of perioperative complications. Although EVAR is a minimally invasive technique, lifelong follow-up imaging is necessary due to possible late complications including endoleak, recurrent aneurysm formation, graft infection, migration, kinking and thrombosis. The total rate of complications after EVAR is estimated at approximately 30%, and the rate of complications that require intervention is 2–3%. Early detection and progression analysis of such situations is crucial for proper intervention.

Self expandable stent application to prevent limb occlusion in external iliac artery during endovascular aneurysm repair

Purpose

Iliac extension of stent-graft during endovascular aneurysm repair (EVAR) increases the incidence of limb occlusion (LO). Hypothetically, adjunctive iliac stent (AIS) could offer some additional protection to overcome this anatomic hostility. But still there is no consensus in terms of effective stent characteristics or configuration. We retrospectively reviewed our center's experience to offer a possible answer to this question.

Methods

Our study included 30 patients (38 limbs) with AIS placed in the external iliac artery (EIA) from January 2010 to December 2013. We classified iliac tortuosity based on anatomic characteristics. AIS's were deployed in EIA with a minimum 5-mm stick-out configuration from the distal edge of the stent-graft.

Results

According to the iliac artery tortuosity index, grade 0, grade 1, and grade 2 were 5 (13.2%), 30 (78.9%), and 3 (7.9%), respectively. The diameter of all AIS was 12 mm, which was as large as or larger than the diameter of the stent-graft distal limb. SMART stents were preferred in 34 limbs (89.5%) and stents with 60-mm length were usually used (89.5%). During a mean follow-up of 9.13 ± 10.78 months, ischemic limb pain, which could be the sign of LO, was not noticed in any patients. There was no fracture, kinking, migration, in-stent restenosis, or occlusion of AIS.

Conclusion

The installation of AIS after extension of stent-graft to EIA reduced the risk of LO without any complications. AIS should be considered as a preventive procedure of LO if stent-graft needs to be extended to EIA during EVAR.

Percutaneous approach to the treatment of a totally occluded abdominal aortic stent graft

Aorto femoral bypass is usually the recommended therapy for diffuse disease involving the aorta and iliac arteries. In this case report, a case involving a chronic endovascular abdominal aortic stent graft occlusion in which percutaneous angioplasty was performed via a transbrachial and transfemoral approach is presented. This case emphasized that occlusion of an endovascular abdominal aortic stent graft can also be treated, primarily, with an endovascular technique.

Tratamento endovascular da oclusão de ramo ilíaco de endoprótese bifurcada de aorta abdominal: trombectomia rotativa e aspirativa seguida de angioplastia com stent primário

A oclusão de ramo ilíaco de endoprótese bifurcada de aorta surge como complicação decorrente da correção endovascular do aneurisma de aorta abdominal e várias abordagens terapêuticas têm sido empregadas para o tratamento dessa complicação em casos de isquemia de membro inferior. Apresentamos dois casos de tratamento totalmente percutâneo da oclusão de ramo ilíaco de endoprótese de aorta abdominal com dispositivo de trombectomia rotativa e aspirativa seguida de angioplastia com stent primário, sem complicações operatórias.

Complications after endovascular aneurysm repair

Endovascular aneurysm repair (EVAR) has become an established technique for the treatment of many infrarenal aortic aneurysms. Although EVAR is obviously less invasive than open surgical repair, it is not free of complications. These can potentially result in severe morbidity or even mortality, stressing the need for an early detection and subsequent treatment. In this review article, the pathophysiology, diagnosis, and treatment of the most common complications of EVAR, with the exception of endoleaks, are described.

Treatment of complications following endovascular repair of abdominal aortic aneurysms

Endovascular aneurysm repair (EVAR) is an important treatment option for abdominal aortic aneurysms, with lower perioperative morbidity and mortality rates than open surgical aneurysm repair. However, EVAR is associated with several unique complications that are not encountered with surgical repair such as endoleaks, graft migration, and renal artery occlusion. Preservation of the morbidity and mortality advantages of EVAR relies on the successful treatment of these complications by minimally invasive, endovascular approaches. Some of the techniques used to treat EVAR complications include balloon dilation and stenting, deployment of additional stent-graft pieces, coil embolization, and thrombolysis. Although the employment of these endovascular salvage techniques is common, data regarding their intermediate- to long-term efficacy is sparse, and further studies are needed to determine their efficacy in preventing conversion to open aneurysm repair and aneurysm rupture.

Limb Graft Occlusion Following EVAR: Clinical Pattern, Outcomes and Predictive Factors of Occurrence

INTRODUCTION

We reviewed our experience with limb occlusion after EVAR in order (1) to assess the clinical pattern and treatment options (2) to assess outcomes and (3) to identify predictive factors of occurrence.

MATERIALS AND METHOD

Between 1995 and 2005, 460 AAA patients were electively treated with a variety of commercially available stent grafts. There were 369 bifurcated and 91 aortouniiliac grafts (829 limbs). Follow-up included physical examination, plain X-ray, Duplex ultrasonography, and spiral computed tomographic scans at 1, 6, 12 months and annually thereafter. All pertinent data were collected prospectively and analysed retrospectively. The follow-up period ranged from Day 0 to 104 months, with a median follow-up of 23.4 months.

RESULTS

36 limbs in 33 patients (7.2%) occluded between Day 0 and 71 months (average: 9.5 months) after EVAR. Presentation was acute ischemia in 11 cases, rest pain in 9, claudication in ten. Four occlusions remained asymptomatic and two occurred intraoperatively. Treatment was femoro-femoral cross-over graft in 19 cases, axillo-femoral bypass in three, thrombectomy and stent in three, thrombolysis and stent in nine, and conservative in two. One patient (3%) died of multiple organ failure after thrombolysis. There was no amputation. Reocclusions occurred in two patients (6.1%). Multivariate logistic regression showed that kinking (odds ratio [OR] 11.9; confidence interval [CI] 3.39-42.1; p=0.0001), first graft generation (OR 2.87; CI 1.25-6.62; p=0.017) and younger age (OR 1.05; CI 1.00-1.09; p=0.034) were independently related to the occurrence of graft limb occlusion.

CONCLUSION

Acute graft limb occlusion is not rare after EVAR. The frequency of limb occlusion has declined with current stent grafts generation. Although surgery and endovascular treatments are efficient and safe, development of a graft limb kink should lead to aggressive pre-emptive treatment to prevent occlusion.

Endovascular Graft Limb Occlusion After an Anterior Resection for Rectal Cancer: Report of a Case

An endovascular aneurysm repair has become an important therapeutic option for the management of patients with aortic aneurysms. Early advantages of the endovascular technique have been well documented. Patients with aortic aneurysms undergoing these procedures are usually elderly, which increases the likelihood of comorbidities. With the increased use of vascular devices, potential complications such as graft limb occlusion need to be widely understood, so they can be recognized and treated early. We recently treated an 85-year-old man with acute endovascular graft limb occlusion after an elective anterior resection for rectal cancer, and we discuss some factors that may have contributed to this complication.

Adjunctive primary stenting of Zenith endograft limbs during endovascular abdominal aortic aneurysm repair: Implications for limb patency

OBJECTIVE

Endograft limb occlusion is an infrequent but serious complication of endovascular abdominal aortic aneurysm (AAA) repair. The insertion of additional stents within the endograft limb may prevent future occlusion. This study evaluates limb patency with and without adjunctive stenting of endograft limbs at the time of endovascular AAA repair.

METHODS

We performed a retrospective review of 248 patients who underwent endovascular abdominal aortic aneurysm repair with the Zenith AAA endovascular graft between 1999 and 2004. Among these patients, two groups were identified: 64 patients with adjunctive stents placed in 85 limbs and 184 patients without additional bare stent placement in endograft limbs at the time of endovascular AAA repair.

RESULTS

Women comprised 23% of stented and 11% of unstented patients (P = .02). The mean length of follow-up in the stented and unstented groups was 2.0 years. There were 13 instances of limb thrombosis in 13 patients (5.2% of patients, 2.7% of limbs), all in the unstented group. No limb occlusions occurred in the presence of adjunctive bare metal stents. Seventy-three percent of the occlusions occurred < or = 6 months of endovascular AAA repair. Two patients (15%) had no symptoms of lower-extremity ischemia despite graft limb occlusion and did not undergo intervention. The others underwent thrombectomy (n = 2), thrombectomy with bare stent placement (n = 3), femoral-femoral bypass (n = 4), thrombolysis (n = 1), and thrombolysis with bare stent placement (n = 1). Of the seven who underwent thrombectomy or thrombolysis, three had no additional stents placed at the secondary procedure, and two of these three went on to rethrombose. By life-table analysis, primary patency at 3 years in the stented and nonstented limbs was 100% +/- 0% and 94% +/- 3%, respectively (P = .05).

CONCLUSIONS

The intraoperative insertion of additional bare metal stents appeared to eliminate the risk of thrombosis and was without complication. Of the 85 stented limbs in this series, not one occluded. The overall rate of limb thrombosis was low, with most limb occlusions occurring < or = 6 months of stent-graft insertion, and would probably have been even lower had we been able to identify all high-risk cases for prophylactic adjunctive stenting. Limb occlusion denotes an underlying problem with the graft, which if left untreated after thrombectomy or thrombolysis will lead to rethrombosis. Postoperative imaging was of little value in detecting impending limb occlusion. Based on these findings, we believe one should identify and stent any limbs that appear to be at risk for thrombosis, but this study lacks the data to predict which limbs need stenting.

Aneurysm Sac Re-Expansion After Thrombolysis

PURPOSE

To present a case of delayed abdominal aortic aneurysm (AAA) re-expansion after thrombolysis for endograft limb occlusion.

CASE REPORT

A 68-year-old man underwent AAA exclusion with an AneuRx stent-graft in 1999. Five years later, he developed right limb thrombosis of the endograft. He underwent right limb thrombolysis and AngioJet thrombectomy. The patient experienced abdominal and back pain during the procedure, and the aneurysm sac, which had remained reduced in size for several years, acutely re-expanded. The patient was managed conservatively. The fluid that accumulated in the sac was reabsorbed, and the AAA returned to its previous dimensions at 1-month follow-up.

CONCLUSION

Symptomatic re-expansion of the aneurysm sac after AngioJet rheolytic thrombectomy may occur when the graft is stripped of neointima by the "power-pulse" spray of lytic agent, allowing serum to seep into the sac. Based on this experience, we advise caution when delivering thrombolytics using the AngioJet "power-pulse" spray mode in patients with a thrombosed stent-graft.

Endovascular graft limb occlusion

Endovascular aneurysm repair (EVAR) has undergone a tremendous evolution in the nearly 15 years since it was first described. Continual refinement of the technology and techniques associated with EVAR and the respectable short-term results of this procedure led the United States Food and Drug Administration to approve several devices for the endovascular treatment of abdominal aortic aneurysm (AAA). There has been a corresponding rapid dissemination of this technology throughout the vascular surgery community in the United States. Availability and critical analysis of mid- and long-term follow-up data on the increasing number of patients who have undergone EVAR has begun to raise questions about the long-term durability and effectiveness of EVAR. Numerous complications of EVAR are now recognized and well described in the literature. One of these is graft limb dysfunction. Graft limb occlusion occurs in a significant number of patients and it is imperative that physicians who perform EVAR have a thorough understanding of this condition. There are a variety of factors that predispose patients to development of graft limb occlusion. These factors can be classified as either anatomic or graft-related. When patients present with graft limb occlusion, endovascular treatment is usually possible and it is highly effective. Some cases require traditional surgical treatment. Prevention of graft limb occlusion is of paramount importance. It can only be achieved with an aggressive search for graft limb compromise and liberal use of angioplasty and/or stenting at the time of graft implantation.

Initial management and outcome of aortic endograft limb occlusion

OBJECTIVE

The purpose of this study was to determine the differences in outcome related to initial management of aortic endograft limb occlusion (ELO).

METHODS

During a 7-year period, 823 endovascular aneurysm repairs (EVARs) resulted in 25 ELOs in 22 patients. The initial management and outcome of these ELOs were reviewed. Median follow-up after ELO was 24.2 +/- 16.8 months.

RESULTS

Initial EVARs included both unsupported unibody (n = 5) and supported modular (n = 17) devices. ELO was significantly more common in the unsupported unibody graft design (P <.024) and with extension of the graft limb to the external iliac artery (P <.001). ELO was managed with an endovascular approach (EVA), including some combination of mechanical thrombectomy (n = 8), angioplasty with or without stenting (n = 8), and thrombolysis (n = 2) in 12 patients and bypass procedures (femoral-femoral bypass, n = 11; axillofemoral bypass, n = 1; and aortofemoral bypass, n = 1) in 13. At 12-month follow-up, freedom from secondary procedures with EVA was 80.2 +/- 17.7% versus 53.2 +/-17.1% with extra-anatomic bypass (EB) (P = NS). Secondary patency was 100% with EVA and 80.6 +/- 14.4% with EB (P = NS). Of the 12 EVAs, there was 1 (8.3%) perioperative mortality with EVA and none with EB. EB failure was directly attributed to donor limb occlusion in 4 of 6 EVAs (67%), and when this occurred it resulted in bilateral lower extremity ischemia. Amputation was required in 2 of 12 (16.7%) EBs versus none of the 12 EVAs (P = NS). EVA never resulted in graft dislodgement or endoleak but did identify an underlying treatable cause in 8 of 12 (67%).

CONCLUSION

Both EVA and EB are acceptable management strategies for ELO. The potential risk of graft dislodgement was not observed with an EVA. If EB is employed, assessment of the donor limb and treatment of any underlying lesions is advisable in an attempt to minimize future donor limb occlusion.

Outcomes of secondary interventions after abdominal aortic aneurysm endovascular repair

PURPOSE

We assessed the distribution of secondary interventions after aortic stent grafting (EVAR) performed to treat infrarenal abdominal aortic aneurysm (AAA), and evaluated clinical success and survival in patients who underwent a secondary procedure (group 2) compared with patients who did not undergo a secondary procedure (group 1).

METHODS

Two hundred fifty patients (mean age, 71.3 years) with asymptomatic AAAs (mean aneurysm diameter, 54.5 mm) underwent treatment with commercially available stent grafts. Mean follow-up was 28 months (median, 25 months). Secondary procedures were defined as any additional procedures performed after initial graft placement to treat endoleak, migration, kinking, stenosis, or occlusion. Overall clinical success was defined according to reporting standards of the Society for Vascular Surgery/American Association for Vascular Surgery.

RESULTS

Sixty-eight patients (27%) required 112 secondary procedures, with a mean time from initial graft placement of 18.2 months. Patients who received grafts since removed from the market required more secondary procedures (59%, procedure:patient ratio) compared with patients who received devices still on the market (21%; P =.001). Thirty-six patients (53%) required a single secondary procedure, 24 patients (35%) required two procedures, 5 patients (10%) required three procedures, 2 patients (3%) required four procedures, and 1 patient required five secondary procedures. Ninety-eight procedures (87%) were performed with endovascular methods, including placement of 42 additional covered stent grafts (36 iliac, 6 aortic), with a success rate of 85%; 35 embolization procedures (21 lumbar, 9 internal iliac artery, 5 mesenteric), with only 23 (65%) successful; 14 angioplasty procedures, with 85% successful; 4 thrombolysis procedures, 2 of them successful (50%); and 3 successfully placed new endografts within a previous endovascular graft. Surgical secondary operations included nine femorofemoral bypass procedures and three femoral thromboendarterectomies, all of which remain patent; one cerclage of an external iliac limb; and one laparoscopic repair of a type II endoleak, which was successful. Overall clinical success rate for EVAR was 84% (211 of 250) in this series. Clinical success rate in groups 1 and 2 was 91% (166 of 182) versus 66% (45 of 68; P =.001) if all endoleaks on the most recent computed tomography scans are taken into account, and 94% (171 of 182) versus 76% (52 of 68; P =.001) if type II endoleak without aneurysm growth is not considered failure. The survival rate and rupture-free survival in groups 1 and 2 were, respectively, 97.7% +/- 1.0% and 98.5% +/- 1.4% at 1 month, 95.9% +/- 1.5% and 96.9% +/- 2.1% at 6 months, 94.4% +/- 2.0% and 93.2% +/- 3.4% at 1 year, and 80.8% +/- 5.2% and 88.5% +/- 5.0% at 3 years (P =.273, log-rank test).

CONCLUSION

With close follow-up and a significant number of secondary operations, this 8-year experience has not included any aneurysm ruptures to date. Secondary operations did not lead to increased mortality, but were associated with more surgical conversions and with a higher clinical failure rate.

Successful treatment of aortic endograft thrombosis with rheolytic thrombectomy

PURPOSE

To report the benefits of rheolytic thrombectomy for treating aortic endograft thrombosis.

METHODS

Of 40 patients who received the Ancure bifurcated endograft to treat abdominal aortic aneurysm (AAA) during a 9-month period, 6 (15%) patients (6 men; mean age 62.6 years, range 53-77) developed thrombosis of the endograft at an average of 9 weeks (range 1-20 months). Five patients were taking aspirin, and 3 were on warfarin therapy for atrial fibrillation. Immediately after angiography, rheolytic thrombectomy was used to remove the thrombus, followed by adjunctive procedures to treat the underlying pathology.

RESULTS

Causes were kinking or extrinsic compression of the graft limb in 5 cases and thrombosis of the surgical closure site in a common femoral artery. Mechanical thrombectomy was successful in restoring circulation in all cases; thrombolysis was used in 1. All 6 patients had additional stents placed in the graft limbs, re-establishing patency. There was no mortality or recurrent thrombosis in a follow-up that has extended to 26 months, but 1 patient required additional stenting for subsequent focal kinking of a graft limb above the previously implanted stent.

CONCLUSIONS

Rheolytic thrombectomy can safely and effectively treat endograft thrombosis after endovascular AAA repair. Additional thrombolytic agents, angioplasty, and stenting may be needed to correct the underlying causes of the thrombosis. Prophylactic stenting of iliac limbs at the time of implantation in patients with complex anatomy may prevent thrombosis of unsupported bifurcated endografts.

The Zenith aortic stent-graft: a 5-year single-center experience

PURPOSE

To evaluate the efficacy and midterm results of the Zenith stent-graft in the treatment of abdominal aortic aneurysms (AAA).

METHODS

Since March 1994, 364 patients have undergone endovascular repair of infrarenal AAA. Of the 94 who were treated with the Zenith stent-graft from 1996 to 2002, 88 patients (82 men; mean age 72.6 +/- 6.5 years, range 47-88) with at least 6-month follow-up were analyzed. Sixty-one (69.3%) patients were considered at high risk for intervention; 7 ruptured AAAs were treated emergently. In all, 68 (77.3%) bifurcated stent-grafts (including 18 TriFab systems) and 20 aortomonoiliac configurations were used. Cumulative data on endoleak, migration, secondary procedures, and survival were evaluated with Kaplan-Meier analyses.

RESULTS

Implantation success was 97.7%; 2 (2.3%) access-related failures were converted to open repair (1 immediate, 1 at 3 months). There were 3 (3.4%) graft limb thromboses (2 immediate, 1 late), 3 (3.4%) cases of colon ischemia due to embolization in 1 and hypogastric artery occlusion in 2, and 1 (1.1%) renal infarction due to embolism. Three (3.4%) patients died within 30 days. Eleven (12.5%) endoleaks and 1 (1.1%) late endograft migration were recorded. The 5-year cumulative endoleak and migration rates were 15% and 7%, respectively. Sixty-three (71.6%) patients did not present any complication related to the repair during a mean follow-up of 20.6 +/- 14.9 months (range 6-68); notably, no complications were associated with the 18 TriFab systems. Six (6.8%) secondary procedures were performed (31% 5-year cumulative secondary procedural rate). All 6 (6.8%) aneurysm-related deaths (the 3 perioperative, 2 from late AAA rupture, and 1 during a secondary procedure) and 14 of 18 (20.4%) non-aneurysm-related deaths occurred in high-risk patients; the 5-year cumulative survival rates were 57% for any death and 92% for aneurysm-related deaths.

CONCLUSIONS

The Zenith stent-graft appears both safe and effective in terms of midterm outcome of endovascular aortic aneurysm repair.

Eligibility rates of ruptured and symptomatic AAA for endovascular repair

PURPOSE

To determine the anatomical eligibility rate for endovascular repair of ruptured and symptomatic abdominal aortic aneurysms (AAA) using commercially available endografts.

METHODS

In a retrospective review, 28 preoperative computed tomographic (CT) scans were examined from among 83 patients who underwent surgical repair of a ruptured or acutely symptomatic AAA at a university-based tertiary care center during the past 10 years. The proximal aortic neck, aneurysm, and iliac dimensions were compared to corresponding measurements from 100 preoperative CT scans from patients who underwent elective repair of asymptomatic AAA. Based on expanded selection criteria for the 2 FDA-approved endografts (AneuRx and Ancure), eligibility rates for endovascular repair were compared between patients with ruptured/symptomatic and asymptomatic AAAs.

RESULTS

The proximal neck of the ruptured/symptomatic AAAs was on the average 2 mm larger in diameter (25 +/- 4 versus 23 +/- 3 mm, p=0.04) and 7 mm shorter (16 +/- 10 versus 23 +/- 14, p=0.017) than asymptomatic AAAs. The maximum AAA diameter was significantly larger in the ruptured/symptomatic group (64 +/- 16 mm) than in the asymptomatic group (58 +/- 11 mm, p=0.033). Of the 28 ruptured/symptomatic AAAs assessed morphologically, 13 (46%) were anatomically eligible for endovascular repair compared to 74 of the 100 asymptomatic AAAs (p=0.006). The main cause for exclusion was an unfavorable proximal neck, which was present in 15 (54%) of the 28 ruptured/symptomatic AAAs and in 24 (24%) of the 100 asymptomatic AAAs (p=0.003).

CONCLUSIONS

A significantly smaller proportion of patients presenting with ruptured/symptomatic AAA are anatomically eligible for endovascular AAA repair compared to patients with asymptomatic AAA due to unfavorable proximal neck anatomy.

Endograft limb occlusion and stenosis after ANCURE endovascular abdominal aneurysm repair

OBJECTIVE

The purpose of this study was to define the incidence and treatment of endograft limb stenosis or occlusion (endograft limb dysfunction [ELD]) in a single center with the ANCURE unsupported bifurcated or aortouniiliac endograft by using intraoperative completion angiography and postoperative color duplex ultrasound scanning (CDU).

METHODS

Sixty-seven endografts (58 bifurcated, 9 uniiliac) were implanted between February 1996 and July 2000. Intraoperative completion aortography was performed in every patient. Postoperative assessment of the endograft consisted of CDU and computed tomography scanning and kidney, ureter and bladder radiographs within 7 days of implantation, at 3 and 6 months after the operation, and every 6 months thereafter.

RESULTS

At the time of endograft implantation, widely patent normal-appearing endograft limbs were revealed by means of the initial completion angiogram in 58 of 67 patients (group 1). ELD subsequently developed in seven of these 58 patients (13.4%). The results of the completion angiogram were not normal in the remaining nine patients (group 2), leading to the deployment of a self-expanding stent within the endograft limbs. The results of subsequent angiography were normal. No ELD has occurred in any patient in group 2 to date. The primary assisted patency rate at 30 months was 88% +/- 5.2% for group 1 versus 100% +/- 0% for group 2 (P = not significant, Log-rank test). Postoperative ELD occurred in seven patients (10.4%). Endovascular graft thrombosis occurred in three patients (3 endograft limbs). In each case, an endovascular approach was attempted; however, the guidewire would not traverse the occluded endovascular graft limb. Revascularization was accomplished by means of femorofemoral bypass grafting. Endovascular graft stenosis occurred in four patients (4 endograft limbs). Three patients with bifurcated endografts and limb stenosis who had no symptoms diagnosed by means of CDU were successfully treated by means of balloon angioplasty with self-expanding stent implantation, and the endograft limbs remained patent at 3, 5, and 26 months follow-up. The remaining patient who had an aortouniiliac endograft with recurrent severe stenoses underwent endograft explantation and aortobifemoral bypass grafting. The overall incidence of ELD during or after endovascular abdominal aortic aneurysm repair was 23.8% (16 of 67 patients).

CONCLUSION

Unsupported endografts are at risk for developing ELD. The use of stents for limb support at the time of the initial endograft implantation may prevent subsequent ELD and bears further study. Endograft limb occlusion usually presents with acute severe ischemic symptoms, and the failure of operative thrombectomy necessitates femorofemoral artery bypass grafting. Endograft limb stenosis is identified by means of CDU surveillance in the postoperative period. Prompt treatment with percutaneous transluminal angioplasty/stent yields satisfactory primary assisted patency. Intraoperative intravenous ultrasound scanning, oblique angiograms, pressure gradients, and completion angiography may be necessary to detect and treat ELD.

Postoperative management: buttock claudication and limb thrombosis

As a result of endovascular repair of abdominal aortic aneurysms and the necessary associated adjunctive procedures, postoperative buttock claudication and limb thrombosis are complications that every physician who implants stent-grafts should be able to recognize and treat. Whereas the presenting complaints of these complications can be quite obvious, the treatment of them may be not so simple. Studies have shown that 28% of patients who underwent embolization of one or both hypogastric arteries develop buttock claudication. Yet 78% of these affected patients spontaneously resolve their symptoms. Strategies to both minimize and successfully treat this complication are obviously of the utmost importance. Likewise, limb thrombosis can be easy to recognize, but treatment strategies and methods to limit this complication can be quite complex and remain somewhat controversial. One center was able to reduce their limb thrombosis rate from 17% to 0% through the use of intravascular ultrasound and aggressive adjunctive stenting. The purpose of this article is to first review the data concerning these complications and then to discuss treatment strategies that are designed to minimize and treat the actual complication.