Endovascular stent-grafts for aneurysms of the femoral and popliteal arteries

Endovascular Management of a Large Femoral Pseudoaneurysm: A Case Report and Literary Review

Femoral artery pseudoaneurysms have an increased incidence over the past few years due to the rise in percutaneous catheterization and so have the potential treatment options. Ultrasound-guided thrombin injection has been strongly studied, and data have shown its efficacy, safety, and superiority to ultrasound-guided compression therapy as well as open surgical repair; however, a less well-studied approach that appears to be burgeoning is endovascular stent repair. Many small studies and case reports have shown this option to be not only effective but also safe and might be the treatment option of choice in patients who are deemed high risk for surgical intervention or with complicated anatomical considerations at the site of injury. In this case report, we describe a 71-year-old man with an expanding right groin hematoma which was discovered to be a right superficial femoral artery pseudoaneurysm with a venous fistula connection to the common femoral vein. Due to the patient’s venous fistula component, high surgical risk from substantial comorbidities, and large pseudoaneurysm size with a wide pseudoaneurysm neck, thrombin injection, compression therapy, and open surgical repair were ruled out as potential treatments; therefore, endovascular stent repair was performed. The procedure was successful, as was the patient’s postoperative period. This case report and literary review can support and further validate the usage of endovascular stent repair to treat femoral artery pseudoaneurysms.

Patient-specific computational fluid dynamics of femoro-popliteal stent-graft thrombosis

Intra-stent thrombosis is one of the major failure modes of popliteal aneurysm endovascular repair, especially when the diseased arterial segment is long and requires overlapping stent-grafts having different nominal diameters in order to accommodate the native arterial tapering. However, the interplay between stent sizing, post-operative arterial tortuosity, luminal diameter, local hemodynamics, and thrombosis onset is not elucidated, yet. In the present study, a popliteal aneurysm was treated with endovascular deployment of two overlapped stent-grafts, showing intra-stent thrombosis at one-year follow-up examination. Patient-specific computational fluid-dynamics analyses including straight- and bent-leg position were performed. The computational fluid-dynamics analysis showed that the overlapping of the stent-grafts induces a severe discontinuity of lumen, dividing the stented artery in two regions: the proximal part, affected by thrombosis, is characterized by larger diameter, low tortuosity, low flow velocity, low helicity, and low wall shear stress; the distal part presents higher tortuosity and smaller lumen diameter promoting higher flow velocity, higher helicity, and higher wall shear stress. Moreover, leg bending induces an overall increase of arterial tortuosity and reduces flow velocity promoting furtherly the luminal area exposed to low wall shear stress.

The Incidence of Popliteal Artery Aneurysms in Patients with Abdominal Aortic Aneurysms

Purpose

We sought to evaluate the incidence of popliteal artery aneurysms (PAAs) in patients who have a diagnosis of abdominal aortic aneurysm (AAA).

Methods

It has been previously documented that patients with AAA have a greater incidence of PAA. During the past 11 years, 163 patients presented to the Vascular Laboratory at Harborview Medical Center with an AAA. Seventy-one (44%) of these patients had popliteal arteries evaluated using duplex ultrasound (Advanced Technology Laboratory 3000, 5000, 9000). The popliteal artery was measured in the anteroposterior and transverse diameters. A PAA was defined as an artery larger than 1.5 cm and/or an ectatic artery with thrombus present.

Results

Fourteen patients had a PAA; six patients (43%) had PAA bilaterally, for a total of 20 aneurysms. Nineteen (95%) aneurysms had thrombus present. Various interventional treatments were used: five limbs (25%) received an arterial bypass graft, two (10%) underwent amputation, and two (10%) received thrombolytic therapy

Conclusions

There is a high incidence of PAA in patients with AAA (19.7% in this series). Patients with a diagnosis of AAA should be screened for PAA and considered for elective repair to prevent the high rate of complications associated with these lesions.

Endovascular Exclusion of Popliteal Artery Aneurysms With Expanded Polytetrafluoroethylene Stent-Grafts: Early Results

There is increasing interest in using endovascular methods instead of surgical reconstruction to treat popliteal artery aneurysms. Exclusive use of the Viabahn stentgraft, a nitinol stent covered with expanded polytetrafluoroethylene, was assessed in the treatment of patients who presented with popliteal artery aneurysms in the absence of acute limb ischemia. Technical success, endoleaks, graft patency, freedom from amputation, and aneurysm sac flow and size changes were assessed by duplex ultrasound. From June 2004 to March 2006, 16 men (mean age, 76 years; range, 65-83) underwent endovascular exclusion of 23 popliteal artery aneurysms (mean diameter, 2.5 cm; range, 1.3-6.7 cm). Nine lesions had partial thrombus on preprocedural duplex imaging. Nineteen of the 23 limbs treated had at least 2-vessel tibial artery runoff. Procedures were performed under local anesthesia using ipsilateral percutaneous antegrade arterial access. All patients received 75 mg/day of clopidogrel afterward. Follow-up assessments included direct clinical examinations and duplex ultrasonography performed 1, 3, 6, and 12 months after the procedure. Primary patency and amputation-free survival were calculated using Kaplan-Meier analysis. Complete aneurysm exclusion (technical success) was achieved in all cases. During the mean follow-up of 7 months (range, 1-21 months), 22 of 23 treated limbs remained asymptomatic. One stent-graft thrombosis occurred 6 months after the procedure and was successfully treated with percutaneous mechanical thrombectomy, balloon angioplasty of a stent-graft stenosis, and insertion of an uncovered nitinol stent. No popliteal artery aneurysm sac size enlargements or endoleaks were detected. At 12 months, the treated limb mean anklebrachial index was 1.0 (range, 0.82-1.31) and the primary and secondary patency rates were 93% and 100%, respectively. Early results with Viabahn endovascular stent-graft exclusion of asymptomatic popliteal artery aneurysms are promising. Patient selection for endovascular repair depends on suitable popliteal artery anatomy, extent of aneurysmal degeneration, and quality of tibial arterial runoff.

Two Decades of Endovascular Repair of Popliteal Artery Aneurysm--A Meta-analysis

OBJECTIVE/BACKGROUND

Over the last two decades endovascular repair (EVR) of popliteal artery aneurysms has emerged as a treatment alternative to conventional open surgical repair (OSR). The aim of this review was to evaluate the safety and efficiency of each repair method, comparing the following outcomes after EVR and OSR: (i) primary patency; (ii) operating time; (iii) length of hospital stay; (iv) peri-operative complications; (v) limb salvage; and (vi) patient survival.

METHODS

The PubMed and Cochrane Central Register of Controlled Trials were searched for publications that compared outcomes after EVR and OSR (last search November 2014). Randomized controlled trials (RCTs), prospective and retrospective observational cohort studies were included. The quality of studies was evaluated using the Newcastle-Ottawa scale and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Random effect models were employed to estimate odds ratios (ORs), mean differences, and hazard ratios (HRs).

RESULTS

One RCT combined with a prospective cohort study and four retrospective cohort studies with an overall total of 652 cases (236 EVR, 416 OSR) were identified. GRADE quality of evidence was low or very low for all outcomes. After a median follow up of 33 months, patients who received EVR showed equal primary patency rates to patients who received OSR (HR 1.46, 95% confidence interval [CI] 0.92-2.33). Lengths of operation and hospitalization were significantly shorter following EVR; rates of 30 day graft thrombosis (OR 3.16, 95% CI 1.31-7.62) and 30 day re-intervention (OR 2.15, 95% CI 1.02-4.55) were significant higher for patients who received EVR compared with those who received OSR. There was no effect on mortality (OR 2.31, 95% CI 0.37-14.49) or limb loss (OR 0.59, 95% CI 0.16-2.15).

CONCLUSION

EVR of popliteal artery aneurysm showed mid-term results comparable to open surgery and appears to be a safe alternative to OSR. However, the existing empirical evidence base is too fragmentary to draw firm conclusions. Further research and the introduction of population based registries will be needed to allow reliable evaluation of EVR.

Use of stent grafts and coils in vessel rupture and perforation

Vessel rupture and perforation are important complications of percutaneous treatment of coronary and peripheral arterial disease. These complications can result in abrupt vessel closure, distal organ injury, bleeding into the surrounding tissue, and death. Prompt management of such complications is therefore critically important. This paper reviews the management of vessel rupture and perforation, including the use of different types of covered stents (balloon-expandable and self-expanding), as well as the various types of embolization coils. Particular focus will be placed on percutaneous coronary artery and peripheral arterial interventions.

Correção endovascular do aneurisma de artéria poplítea bilateral

O primeiro relato de correção endovascular do aneurisma de artéria poplítea bem-sucedida foi descrito em 1994. Desde então, poucas séries e com apenas alguns casos foram publicadas. A seguir, os autores descrevem dois casos de correção endovascular de aneurisma de artéria poplítea bilateral realizada com sucesso.

Endovascular Treatment of Femoropopliteal Aneurysms: A Five-Year Experience

PURPOSE

To assess the effectiveness of endovascular treatment of femoropopliteal aneurysms (FPAs).

METHODS

In the last 5 years, we have treated 17 FPAs (diameter 21-75 cm, mean 38.4 cm; length 27-100 cm, mean 72.5 cm) in 15 patients (age 57-80 years, mean 70.9 years). The diagnosis was obtained by color Doppler ultrasound (CDU) and the procedure was planned by CT angiography (CTA) and preprocedural angiography. Eight FPAs were excluded with only one stent-graft; in 8 patients, two stent-grafts were positioned; and in 1 patient, three stent-grafts were used. In 14 cases we used a Wallgraft endoprosthesis, in 2 cases a Hemobahn, and in 1 case an Excluder contralateral leg. The patients were followed up with CDU and occasionally with CTA.

RESULTS

Immediate technical success was obtained in 17 of 17 cases (100%). One patient died during the first year. During a mean follow-up of 26.9 months (range 3-60 months) we observed 6 of 16 (38%) stent-graft occlusions (3 of which were recanalized with locoregional thrombolysis and 3 with mechanical thrombectomy). Two stent-grafts were patent at 12 and 24 months. Four patients experienced subsequent occlusions and recanalizations until corrected by surgical bypass (1 at 14 months, 2 at 18 months, and 1 at 36 months). Therefore the primary patency was 63% and assisted patency was 73%.

CONCLUSION

The endovascular approach is a minimally invasive treatment option for FPAs. Moreover endovascular stent-grafting does not necessarily preclude conventional surgical repair, but it can delay it. Longer follow-up will be needed to determine the long-term patency rate.

MANAGEMENT OF POPLITEAL ARTERY ANEURYSMS

BACKGROUND

Popliteal artery aneurysms (PAA) are the most common peripheral aneurysm and are recognized as 'the silent killer of the leg circulation'. The timing and type of interventions used in their treatment is still controversial. This review examines the published data on the natural history, epidemiology, clinical presentation and management options available. The aim of this study is to try and reach a consensus with regards to the best management of PAA.

METHOD

A systematic review of data in the English published works since 1980.

RESULTS

The authors include 53 studies containing 2854 patients with 4291 PAA. Most published data involves retrospective studies and personal experience, with one multicentre study. No randomized controlled studies exist regarding the management of PAA.

CONCLUSIONS

1. Although most PAA are of atherosclerotic origin in old patients, trauma, infection and family history are the main causes in young patients. 2. Great vigilance is needed for diagnosis as only approximately five patients are seen each year by a major vascular centre. There is no place for screening programmes to detect PAA. 3. Approximately 45% of patients are asymptomatic at the time of initial diagnosis. Aortic aneurysms are found in 40% and bilateral PAA in 50% of patients. More than 95% of patients are men with a mean age of 65 years and 45% have hypertension. 4. Surgical reconstruction is recommended for all symptomatic and asymptomatic aneurysms larger than 2 cm. Five-year graft patency rates after surgical repair range from 30 to 97%, with 5-year limb salvage ranging from 70 to 98%. Patient survival rates at 5 and 10 years are 75 and 46%, respectively. 5. If carried out carefully, intra-arterial thrombolysis can safely prepare patients presenting with acute ischaemia from occluded PAA, for surgical revascularization to restore distal run-off. 6. Endovascular repair of a PAA is a feasible option, although little evidence is yet available. 7. Lifelong, careful patient surveillance is essential to detect and treat new aneurysms at other sites.

ENDOVASCULAR REPAIR OF POPLITEAL ARTERY ANEURYSMS: TECHNIQUES, CURRENT EVIDENCE AND RECENT EXPERIENCE

Endovascular repair of popliteal artery aneurysms is a new technique, which has emerged as an alternative to open surgical bypass. However, evidence to support its use is limited. We present a review of current literature relevant to this technique. The MEDLINE search terms were popliteal artery, aneurysm, endovascular, endoluminal and stent. Fifty-eight articles were yielded, of which 21 were studies of endovascular repair by implantation of stent or stent graft of true aneurysms of the popliteal artery. There was only one randomized study. Small numbers of endovascular interventions are reported, with variations in study design and endovascular techniques. Long-term follow-up data is lacking; however, early results have been promising with high rates of initial treatment success. Early thrombosis of stent grafts occurs in approximately 10%, but this does not herald limb loss. Endovascular treatment offers potential benefits over traditional surgery, but needs to be studied further with a large-scale multicentre randomized trial.

True and false aneurysms of the femoral artery

True aneurysms of the femoral artery are uncommon. They are most often identified in elderly males and are frequently associated with aneurysms at other locations. Femoral artery aneurysms that are symptomatic or larger than 2.5 cm should be repaired in order to prevent limb-threatening complications, such as rupture, thrombosis, or embolization. Open repair is the standard method of treatment and should be preceded by evaluation for coexisting aortoiliac or popliteal aneurysms, assessment of superficial femoral artery patency, and determination of the point of origin of the deep femoral artery relative to the aneurysm sac. Femoral artery pseudoaneurysms are most often seen in the setting of previous femoral artery catheterization but may also be associated with trauma, anastomotic leakage, or infection. The majority of femoral pseudoaneurysms less than 3 cm in diameter will spontaneously thrombose and may be observed with serial duplex ultrasound exams in asymptomatic patients. Symptomatic pseudoaneurysms, pseudoaneurysms with a diameter greater than 3 cm, and those found in patients who are anticoagulated should usually be treated. Ultrasound-guided thrombin injection is our preferred method for treating femoral pseudoaneurysm because of its low risk, high success rate, and efficacy in the setting of anticoagulation. Ultrasound-guided compression is an alternative method that may be considered when thrombin products are contraindicated. Open pseudoaneurysm repair should be undertaken in the setting of infection, rapid expansion, or if less-invasive methods are not technically feasible.

Popliteal Artery Aneurysms: Tried, True, and New Approaches to Therapy

Popliteal artery aneurysms are the most common peripheral aneurysm. They are associated with concomitant contralateral popliteal aneurysms and abdominal aortic aneurysms. Patients with unrecognized aneurysms may present with acute limb ischemia and potential for limb loss. Use of preoperative lytic therapy to improve distal runoff prior to exclusion and bypass has significantly improved the outcome from acute thrombosis. Long-term follow-up has shown that both proximal and distal ligation of the aneurysm are important because a thrombosed aneurysm may begin to enlarge after a long period of quiescence. Popliteal aneurysms are now being treated with covered stents. This article delineates the current evaluation, preoperative planning, and surgical and endovascular approaches to this disease. With proper diagnosis and repair, excellent limb salvage and postoperative function has become the norm.

Open repair versus endovascular treatment for asymptomatic popliteal artery aneurysm: Results of a prospective randomized study

PURPOSE

The aim of this prospective randomized study was to evaluate the relative risks and advantages of using the Hemobahn graft for popliteal artery aneurysm (PAA) treatment compared with open repair (OR). The primary end point was patency rate; secondary end points were hospital stay and length of surgical procedure.

METHODS

The study was a prospective, randomized clinical trial carried out at a single center from January 1999 to December 2003. Inclusion criteria were an aneurysmal lesion in the popliteal artery with a diameter > or = 2 cm at the angio-computed tomography (CT) scan, and proximal and distal neck of the aneurysm with a length of > 1 cm to offer a secure site of fixation of the stent graft. Exclusion criteria were age < 50 years old, poor distal runoff, contraindication to antiplatelet, anticoagulant, or thrombolytic therapy, and symptoms of nerve and vein compression. The enrolled patients were thereafter prospectively randomized in a 1-to-1 ratio between OR (group A) or endovascular therapy (ET) (group B). The follow-up protocol consisted of duplex ultrasound scan and ankle-brachial index (ABI) measured during a force leg flexion at 1, 3, and 6 months. Group B patients underwent an angio-CT scan and plain radiography of the knee with leg flexion (> 120 degrees) at 6 and 12 months, and then yearly.

RESULTS

Between January 1999 and December 2003, 30 PAAs were performed: 15 OR (group A) and 15 ET (group B). Bypass and exclusion of the PAA was the preferred method of OR; no perioperative graft failure was observed. Twenty stent grafts were placed in 15 PAAs. Endograft thrombosis occurred in one patient (6.7%) in the postoperative period. The mean follow-up period was 46.1 months (range, 12 to 72 months) for group A and 45.9 months (range, 12 to 65 months) for group B. Kaplan-Meier analysis showed a primary patency rate of 100% at 12 months for OR and 86.7% at 12 months with a secondary patency rate of 100% at 12 and 36 months for ET. No statistical differences were observed at the log-rank test. The mean operation time (OR, 155.3 minutes; ET, 75.4 minutes) and hospital stay (OR, 7.7 days; ET, 4.3 days) were statistically longer for OR compared with ET (P < .01).

CONCLUSION

We can conclude, with the power limitation of the study, that PAA treatment can be safely performed by using either OR or ET. ET has several advantages, such as quicker recovery and shorter hospital stay.

Treatment of Extracranial and Intracranial Aneurysms and Arteriovenous Fistulae Using Stent Grafts

OBJECTIVE:

Treatment of 11 patients with aneurysms or arteriovenous fistulae of the craniocervical arteries with stent grafts.

METHODS:

Peripheral stent grafts were deployed in two extracranial internal carotid arteries. Coronary stent grafts were used to treat two giant aneurysms, five direct carotid-cavernous fistulae, one vertebrojugular fistula, and two dissecting aneurysms of the vertebral artery (V2 and V4).

RESULTS:

Stent grafts were used successfully in two extracranial internal carotid and two extracranial vertebral arteries, one dissecting aneurysm of the intracranial vertebral artery, one giant aneurysm and one pseudoaneurysm of the cavernous internal carotid artery, and five direct carotid-cavernous sinus fistulae. Angiographic follow-up examinations (available in nine patients; obtained at 3 mo to 5 yr; average, 24 mo) revealed normal vessel caliber, and the stent grafts in all 9 of 11 initial patients were patent. There was a recurrent saccular aneurysm adjacent to the stent graft in the patient with the intracranial vertebral artery aneurysm. The following five complications were encountered: transient hemiparesis (n = 2), increased hemiparesis, post-procedural management-related fatality, and ICA dissection. In six patients, stent graft deployment was accomplished without any technical or clinical complication. There were no permanent neurological deficits consequent to stent graft placement.

CONCLUSION:

Stent grafts are a useful tool for the endovascular treatment of head and neck aneurysms and direct arteriovenous fistulae in selected patients. The major disadvantage of the currently available stent grafts is their lack of mechanical flexibility. Maneuvering stent grafts in the intracranial arteries carries the risk of iatrogenic vessel dissection and may require supportive measures and protection of the target site by conventional stents.

Endovascular Treatment of Popliteal Artery Aneurysms

OBJECTIVE

To present the results of the endovascular treatment of popliteal artery aneurysms.

METHODS

From April 1999 to January 2002, 11 patients, aged 40-94 years, with 12 popliteal aneurysms were treated. Nine (75%) underwent an endoluminal repair, of whom three were done emergently due to an aneurysm rupture. Aneurysm diameter was 28-105 (mean 69) mm. A Hemobahn stent graft was inserted in six, Wallgraft in two and Passager in one case.

RESULTS

During a mean follow-up of 14 (3-31) months, four (44%) thromboses occurred: two in the early postoperative period (30 days) and two during the late postoperative period. Two of the four occluded grafts were successfully reopened, and in the one a stenosis of the distal end of the stent graft was treated with balloon dilatation. Patency rates at 1 and 12 months were 64/47% (primary patency) and 88/75% (secondary patency), respectively.

CONCLUSION

Initial experience with endovascular treatment of the popliteal aneurysm in high-risk patients yielded modest results. Larger number of patients and further follow-up time is necessary to evaluate the long-term results.

Surgery of popliteal artery aneurysms: a 12-year experience

BACKGROUND

Management of asymptomatic popliteal aneurysm is controversial, and the prognosis for acutely thrombosed aneurysm is notoriously poor. We evaluated the management and outcome for popliteal aneurysm.

PATIENTS AND METHODS

A retrospective review of all patients with popliteal aneurysm between 1988 and 2000 was carried out. Fifty-two limbs were operated on in 41 patients. Data collected included findings at presentation, operative details, graft patency, limb salvage, complications, and 30-day mortality.

RESULTS

Initial findings included acute ischemia (n = 14), no symptoms (n = 29), acute rupture (n = 2), chronic ischemia (n = 5), and symptoms of nerve or vein compressive (n = 2). All patients with symptomatic aneurysms and 22 patients with asymptomatic aneurysms (21 larger than 2 cm in diameter, 1 with thrombus at duplex ultrasound scanning) underwent surgery as first-line treatment. Of the 7 patients with asymptomatic aneurysm managed with surveillance with duplex ultrasound scanning, acute ischemia developed in three, 1 aneurysm ruptured, compressive symptoms developed in 1, and 2 remained asymptomatic but required surgery because of aneurysm enlargement (>2 cm). Of the 17 patients with acute ischemia, 13 had neurologic signs and underwent immediate thromboembolectomy (trifurcation alone in 8, ankle-level arteriotomy in 4) and bypass grafting (n = 12) or inlay grafting (n = 1), and the other 4 underwent intra-arterial thrombolysis initially. Of these 4 procedures, 2 were successful and had elective surgery; the other 2 required urgent surgery because of secondary distal embolism and failure of recanalization. Thirteen of the 17 grafts were to the crural vessels. Bypass grafting (medial approach) was used in 16 of the 17 patients with acute ischemia, all 5 patients with chronic ischemia, and the 8 patients with no symptoms. An inlay technique (posterior approach) was used in 16 patients with no symptoms, the 3 patients with symptoms of nerve or vein compression, and 1 patient with acute ischemia. The distal anastomoses were to the below-knee popliteal artery in 35 patients and the crural arteries in 15 patients, using autologous vein. Two of the patients with rupture underwent ligation alone, the other undergoing bypass grafting in addition. The overall 5-year primary patency rate was 69%, secondary patency rate was 87%, and limb salvage rate was 87%. Limb salvage was achieved in 14 of the 17 patients with acute ischemia. Patients with asymptomatic aneurysms had better secondary graft patency (100%) compared with symptomatic aneurysms (74%; P <.01). Acute ischemia, technique used, and crural artery grafts were not predictors of graft failure with either univariate or multivariate analysis. Symptomatic aneurysms were associated with more postoperative complications and greater 30-day mortality (4 of 28 vs 0 of 24).

CONCLUSION

Thromboembolectomy followed by crural bypass grafting is an effective treatment for popliteal aneurysm with severe acute limb ischemia. Outcome is better with surgical management of asymptomatic popliteal aneurysm compared with symptomatic aneurysm.

Treatment of popliteal artery aneurysms with the Hemobahn stent-graft

PURPOSE

To report a prospective study to ascertain the results of popliteal aneurysm treatment with a self-expanding stent-graft.

METHODS

In a recent 3-year period, 21 patients (18 men; median age 67 years, range 52-82) with 23 popliteal aneurysms were treated with Hemobahn stent-grafts. Follow-up evaluation included duplex scanning, ankle-brachial index (ABI) measurements, and radiographic examination of the knee. Outcome measures were occlusion of the stent-graft and limb loss.

RESULTS

Technical success in placing the stent-graft and excluding the aneurysm was 100%. An additional vascular intervention was performed in the same session in 5 (24%) cases. In the other 16 patients, local anesthesia was used in 10 (63%). During a median follow-up of 15 months (range 2-37), 5 (22%) of 23 stent-grafts occluded, resulting in a cumulative patency of 74%. All occlusions occurred within 6 months after the intervention; 2 were successfully recanalized, and none of the 3 patients with persisting occlusion required an amputation.

CONCLUSIONS

The results of this study suggest that endovascular stent-graft repair of popliteal artery aneurysms is feasible. Midterm patency rates are lower compared to traditional surgical repair.

Endovascular aneurysm exclusion along a femorodistal venous bypass in active Behçet's disease

PURPOSE

To report the endovascular repair of dual aneurysms along a femorodistal venous bypass graft in a patient with Behçet's disease.

CASE REPORT

A 55-year-old man of middle European ancestry with Behçet's disease had dual aneurysms evolve along the proximal segment of a femorodistal venous bypass that had been implanted 2.5 years earlier for recurrent false aneurysm formation. Owing to the lack of suitable venous conduits and the active nature of the disease, the aneurysms were successfully excluded with overlapping Hemobahn and Jostent endografts; the immunosuppressive therapy was intensified. Rupture of the aneurysms was successfully prevented, but the stent-grafts thrombosed 6 weeks later owing to exacerbation of the underlying disease.

CONCLUSIONS

Endovascular exclusion of aneurysm in venous bypass grafts in Behçet's disease is feasible. Although the stent-grafts thrombosed, they did prevent rupture of the aneurysms.

Stent-graft repair of a recurrent popliteal arteriovenous fistula

PURPOSE

To describe the successful endovascular treatment of a popliteal arteriovenous fistula with a stent-graft.

CASE REPORT

A 54-year-old man was referred to our hospital with a distal popliteal arteriovenous fistula following an arthroscopic meniscectomy 6 years earlier. Three surgical attempts to close the fistula were undertaken, but the fistula recurred. He now presented with symptoms of progressive venous hypertension with claudication, swelling of the leg, and ulceration at the ankle. The fistula was closed with a stent-graft deployed percutaneously. At 18 months, the patient is doing well; duplex evaluation has documented the patency of the popliteal artery and the stent-graft.

CONCLUSIONS

Endovascular treatment of a popliteal arteriovenous fistula is an alternative to open surgical reconstruction. In this situation, after multiple failed surgical closures and in a leg with extensive venous hypertension, it may be the best treatment option.

Waligraft endoprosthesis for the percutaneous treatment of femoral and popliteal artery aneurysms

PURPOSE

To evaluate the safety and efficacy of the Wallgraft Endoprosthesis for the treatment of femoropopliteal artery aneurysms.

METHODS

From October 1997 to April 2000, 17 patients (13 men; mean age 73.5 +/- 7.1 years) with 7 femoral and 13 popliteal artery aneurysms underwent percutaneous aneurysm exclusion using the Wallgraft Endoprosthesis as part of a larger clinical trial. The mean aneurysm diameters were 37.6 +/- 12.9 mm and 22.3 +/- 8.7 mm, respectively.

RESULTS

Acute procedural success was 100% for femoral aneurysms and 92.3% (12/13) in the popliteal artery owing to one endoleak that resolved after 1 month. There were no complications, and the mean length of stay was 2.2 +/- 3.8 days. Six-month and 1-year aneurysm exclusion rates were 100% for both locations, but 4 (31%) popliteal stent-grafts thrombosed in follow-up. Three were recanalized, but the fourth underwent bypass grafting after 3 thrombotic episodes. The 1-year primary and secondary patency rates were both 100% for the femoral aneurysms and 69% and 92%, respectively, for popliteal repairs. No procedure or device-related deaths occurred.

CONCLUSIONS

Treatment of aneurysms in the femoropopliteal segment appears to be safe and effective with the Wallgraft Endoprosthesis, although longer follow-up in a larger patient group will be needed to determine this technique's potential versus surgical repair.

Popliteal artery aneurysms: is endovascular reconstruction durable?

PURPOSE

To describe an endovascular method of performing femoropopliteal in situ saphenous vein (SV) bypass and popliteal artery aneurysm (PAA) embolization.

METHODS

Twenty-two patients underwent PAA operations. Twelve patients had conventional SV bypasses with PAA proximal and distal ligation, whereas 10 underwent PAA embolization and an endovascular in situ SV bypass (EISB). The endovascular procedure was performed using an angioscopically guided side branch coil occlusion system. The PAAs were coil embolized under fluoroscopic surveillance.

RESULTS

No deaths or wound complications occurred in the EISB group. The mean hospital length of stay (LOS) was 2.1 days. Seven EISB procedures were performed through 2 incisions, whereas 3 operations required an additional incision. One graft occluded at 3 months. All PAAs remained occluded by color-flow ultrasonography at follow-up ranging from 4 to 23 months (mean 13.6); cumulative primary patency was 89%. In the conventional bypass group, no deaths occurred, but 3 (25%) patients had wound complications. The mean LOS was 6.2 days, and 1 graft occluded, giving an 86% cumulative primary patency at 42 months.

CONCLUSIONS

This minimally invasive technique obviates an extensive incision to harvest the SV and ligate the PAA proximally and distally. If long-term endovascular bypass graft patency and PAA occlusion rates prove to be similar to open operative results, the benefits of reduced wound complications, decreased hospital LOS, and increased health care savings support further investigation of this endovascular approach for the treatment of PAA.

First-generation aortic endografts: analysis of explanted Stentor devices from the EUROSTAR Registry

PURPOSE

To examine the structure and healing characteristics of chronically implanted Stentor endografts that were explanted due to migration, endoleak, thrombosis, or aneurysm expansion.

METHODS

The devices were harvested following reoperation (n = 5) or autopsy (n = 1) with implantation times ranging from 13 to 53 months. Structural modifications to the metal components were examined using radiography, endoscopy, and magnetic resonance imaging (MRI). Specimens taken from components of the modular stent-grafts were examined histologically and with scanning electron microscopy (SEM) to assess healing behavior. Physical and chemical stability of the nitinol wires and woven polyester graft material was evaluated using SEM and electron spectroscopy for chemical analysis.

RESULTS

Although the endografts were retrieved for a variety of reasons, they exhibited similar healing and structural modifications. The woven polyester sleeve showed evidence of yarn shifting and distortion, yarn damage, and filament breakage leading to the formation of openings in the fabric. The luminal surface endografts showed incomplete healing characterized by a poorly organized, nonadherent thrombotic matrix of variable thickness. Radiographic and endoscopic observations indicated that structural failure of the grafts, particularly in the main aortic component, was related to severe compaction and dislocation of the metallic frame due to suture breaks. Corrosion marks were observed on some nitinol wires in all devices. Chemical analysis and ion bombardment of the nitinol wires revealed that the surface concentrations of titanium and nickel were not homogenous. The first layer was composed of carbon or organic elements, followed by a stratum of highly oxidized titanium with a low nickel concentration; the titanium-nickel alloy lay beneath these layers.

CONCLUSIONS

Although the materials selected for construction of endovascular grafts appears judicious, the assembly of these biomaterials into various interrelated structures within the device requires further improvement.

First-generation aortic endografts: analysis of explanted Stentor devices from the EUROSTAR Registry

PURPOSE

To examine the structure and healing characteristics of chronically implanted Stentor endografts that were explanted due to migration, endoleak, thrombosis, or aneurysm expansion.

METHODS

The devices were harvested following reoperation (n = 5) or autopsy (n = 1) with implantation times ranging from 13 to 53 months. Structural modifications to the metal components were examined using radiography, endoscopy, and magnetic resonance imaging (MRI). Specimens taken from components of the modular stent-grafts were examined histologically and with scanning electron microscopy (SEM) to assess healing behavior. Physical and chemical stability of the nitinol wires and woven polyester graft material was evaluated using SEM and electron spectroscopy for chemical analysis.

RESULTS

Although the endografts were retrieved for a variety of reasons, they exhibited similar healing and structural modifications. The woven polyester sleeve showed evidence of yarn shifting and distortion, yarn damage, and filament breakage leading to the formation of openings in the fabric. The luminal surface endografts showed incomplete healing characterized by a poorly organized, nonadherent thrombotic matrix of variable thickness. Radiographic and endoscopic observations indicated that structural failure of the grafts, particularly in the main aortic component, was related to severe compaction and dislocation of the metallic frame due to suture breaks. Corrosion marks were observed on some nitinol wires in all devices. Chemical analysis and ion bombardment of the nitinol wires revealed that the surface concentrations of titanium and nickel were not homogenous. The first layer was composed of carbon or organic elements, followed by a stratum of highly oxidized titanium with a low nickel concentration; the titanium-nickel alloy lay beneath these layers.

CONCLUSIONS

Although the materials selected for construction of endovascular grafts appears judicious, the assembly of these biomaterials into various interrelated structures within the device requires further improvement.