"Recovery" vena cava filter: experience in 96 patients.

The purpose of the study was to assess the clinical safety and efficacy of the "Recovery(TM)" (Bard) inferior vena cava (IVC) filter. We retrospectively evaluated the clinical and imaging data of patients who had a "Recovery(TM)" IVC filter placed between January 2003 and December 2004 in our institution. The clinical presentation, indications, and procedure-related complications during placement and retrieval were evaluated. Follow-up computed tomography (CT) examinations of the abdomen and chest were evaluated for filter-related complications and pulmonary embolism (PE), respectively. "Recovery" filters were placed in 96 patients (72 males and 24 females; age range: 16-87 years; mean: 46 years). Twenty-four patients presented with PE, 13 with deep vein thrombosis (DVT) and 2 with both PE and DVT. The remaining 57 patients had no symptoms of thromboembolism. Indications for filter placement included contraindication to anticoagulation (n = 27), complication of anticoagulation (n = 3), failure of anticoagulation (n = 5), and prophylaxis (n = 61). The device was successfully deployed in the infrarenal (n = 95) or suprarenal (n = 1) IVC through a femoral vein approach. Retrieval was attempted in 11 patients after a mean period of 117 days (range: 24-426). The filter was successfully removed in nine patients (82%). Failure of retrieval was due to technical difficulty (n = 1) and the presence of thrombus in the filter (n = 1). One of the nine patients who had the filter removed developed IVC thrombus after retrieval and another had an intimal tear of the IVC. Follow-up abdominal CT (n = 40) at a mean of 80 days (range: 1-513) showed penetration of the IVC by the filter arms in 11, of which 3 had fracture of filter components. In one patient, a broken arm migrated into the pancreas. Asymmetric deployment of the filter legs was seen in 12 patients and thrombus within the filter in 2 patients. No filter migration or caval occlusion was encountered. Follow-up chest CT (n = 27) at a mean of 63 days (range: 1-386) showed PE in one patient (3%). During clinical follow-up, 12 of 96 patients developed symptoms of PE and only 1 of the 12 had PE on CT. There was no fatal pulmonary embolism in our group of patients following "Recovery" filter placement. However, the current version of the filter is associated with structure weakness, a high incidence of IVC wall penetration, and asymmetric deployment of the filter legs.

Aortoiliac gadolinium-enhanced CT angiography: improved results with a 16-detector row scanner compared with a four-detector row scanner.

PURPOSE: To assess the level of vascular enhancement of gadolinium-enhanced aortoiliac computed tomographic (CT) angiography with a 16-detector row CT scanner and to compare it with the results of previous similar studies that used four-detector row CT units. MATERIALS AND METHODS: Eleven gadolinium-enhanced CT angiograms were obtained in 10 consecutive patients with contraindication to iodinated contrast medium with use of a 16-detector row CT scanner. In the region of interest, attenuation measurements (in HU) were obtained from the proximal abdominal aorta to the common femoral arteries during unenhanced, gadolinium-enhanced, and delayed acquisitions. The results were compared to those in the 15 consecutive patients who most recently had similar examinations performed on a four-detector row CT unit. Phantom studies with diluted gadolinium were conducted to compare attenuation between CT units. RESULTS: On four-detector row CT, throughout the scan length, mean enhancement values were 53.8 HU +/- 5.3 and 15.0 HU +/- 2.6 for gadolinium-enhanced and delayed series, respectively. For the 16-detector row CT unit, they were 76.1 HU +/- 3.4 and 21.3 HU +/- 1.3, respectively. As a result of a shorter scan time and a more optimal start time, the 16-detector row CT unit provided significantly greater and more consistent enhancement throughout the scan length compared with the four-detector row CT unit (P =.0106). Similar structures had significantly greater enhancement when 120 kV was applied instead of 140 kV (P =.0495) CONCLUSION: The 16-detector row CT scanner improved gadolinium-enhanced CT angiography results compared with the four-detector row CT unit.

Durability of aortouniiliac endografting with femorofemoral crossover: 4-year experience in the Evt/Guidant trials.

OBJECTIVES: We evaluated mid-term results of the multicenter EVT/Guidant aortouniiliac endograft (AI) trial and ascertained the durability of this endovascular technique in patients unable to undergo standard bifurcated endografting. METHODS: From November 1996 to December 1998, 121 patients were enrolled to receive the AI device on the basis of complex iliac artery anatomy contraindicating bifurcated endografting. Clinical data were centrally collected, and radiographic data were evaluated by core facility. RESULTS: AI placement was technically successful in 113 of 121 patients. At operation, patients who underwent AI had significantly more arrhythmias, congestive heart failure, and peripheral occlusive disease (P <.05) compared with patients who underwent open aneurysmorrhaphy in the EVT/Guidant trials, indicating comorbid features in this anatomic cohort. Distal AI attachment was performed to the external iliac artery in 40 (36%) patients. Median follow-up was 38 months. In the AI group, overall aneurysm diameter decreased over the duration of study from 54.4 +/- 9.6 mm to 44.4 +/- 16.4 mm (P =.004). At 24 and 36 months after repair, reduction in aneurysm size was associated with absence of endoleak (P =.003 and P =.008, respectively). Aneurysms shrunk or remained stable in 109 (96.5%) patients. Endoleak was identified in 52.3% of patients at discharge, and at follow-up in 30.9% at 1 year, 34.8% at 2 years, 28.6% at 3 years, and 30.4% at 4 years. Type II endoleak predominated. Leak from failure to completely occlude contralateral iliac flow accounted for 8 of 58 endoleaks (13.8%) at discharge. Sixteen patients (14.2%) underwent postoperative endoleak treatment; in one of these patients open conversion was necessary at 20 months. Post-procedure thigh or buttock claudication developed in 16 patients (14.2%). Thirteen patients (81.3%) had either distal attachment in the external iliac artery or contralateral type IIA occlusion. Fifteen patients (13.3%) required intervention because of reduced limb flow; one of these patients underwent open conversion at 27 months, and another underwent axillofemoral grafting at 28 months. Device migration was confirmed in 2 (1.8%) patients, without current clinical sequelae. Whereas no femorofemoral graft thromboses occurred, graft infection developed in 3 patients (2.6%). During follow-up, aneurysm in 2 patients ruptured. Late death occurred in 41 patients (36.3%). Twenty-four patients (58.5%) died of cardiopulmonary disease; one death was endograft-related after aneurysm rupture; and one death was related to femorofemoral bypass infection. Actuarial survival was 78.4% (95% confidence interval [CI], 71%-86%) at 2 years and 63.4% (95% CI, 54%-73%) at 4 years. CONCLUSIONS: In patients with significant comorbid conditions and complex iliac anatomy unfavorable for bifurcated endografting, AI with femorofemoral bypass grafting is safe and effective. In most patients this endovascular option provides satisfactory mid-term results.

Renal perfusion defects after endovascular repair of abdominal aortic aneurysms.

PURPOSE: To determine the prevalence of new renal perfusion defects and the association of these events with aneurysm neck atheroma during endovascular stent-graft repair of abdominal aortic aneurysm (AAA). MATERIALS AND METHODS: A retrospective review was performed of 50 patients who underwent AAA repair with bifurcated endovascular stent-grafts without suprarenal components between June 1998 and May 1999. Pre- and postprocedural computed tomographic (CT) angiograms were reviewed to determine the prevalence of new renal perfusion defects. The percent volume of atheroma of the aneurysm neck was determined by three-dimensional volumetric reformation and correlated with prevalence of new postprocedural renal perfusion defects. Follow-up CT angiography was performed between 6 months and 2 years after the procedure and used to evaluate the presence of residual defects and interval changes. RESULTS: Of 50 subjects, 18% (n = 9) had new perfusion defects presumed to be embolic in origin. Follow-up was available for four patients: scarring and cortical thinning consistent with infarction developed in two, whereas the defects resolved in the other two. Analysis of aneurysm neck revealed an average percentage of atheroma of 32% and a range of 0%-73%. In subjects with >/=40% neck atheroma, the prevalence of new renal perfusion defects was 45.4% (five of 11), compared to 10.3% (four of 39) in subjects with <40% neck atheroma. This difference was significant (P =.0170). CONCLUSIONS: In this series, the frequency of renal embolic events associated with AAA endovascular repair was 18%. Prevalence of renal embolic perfusion defects was shown to correlate with volume of aneurysm neck atheroma.

Clinical failures of endovascular abdominal aortic aneurysm repair: incidence, causes, and management.

OBJECTIVE: Despite well-documented good early results and benefits of endoluminal stent graft repair of abdominal aortic aneurysm (J Vasc Surg 2002;35:1137-44.)(AAA), the long-term outcome of this method of treatment remains uncertain. In particular, concern exists that late effectiveness and durability are inferior to that of open repair. To determine the incidence and causes of clinical failures of endovascular AAA repair, a 7-year experience with 362 primary AAA endografts was reviewed. METHODS: Clinical failures were defined as deaths within 30 days of the procedure, conversions (early and late) to open AAA repair, AAA rupture after endoluminal treatment, or AAA sac growth of more than 5 mm in maximal diameter despite endograft repair. Endoleak status per se was not considered unless it resulted in an adverse event. If clinical problems arose but could be corrected with catheter-based therapies or limited surgical procedures, thereby maintaining the integrity of successful stent graft treatment of the AAA, such cases were considered as primary assisted success and not classified as clinical failures. RESULTS: The average follow-up period was 1.5 years. Six deaths (1.6%) occurred after the procedure, all in elderly patients or patients at high risk. Five patients (1.4%) needed early conversion (immediate, 2 days) to open repair for access problems or technical difficulties with deployment, resulting in an implantation success rate of 98.6%. Eight patients (2.2%) underwent late conversion for a variety of problems, including AAA expansion (n = 4), endograft thrombosis (n = 1), secondary graft infection (n = 2), and rupture at 3 years (n = 1). Rupture occurred in an additional two patients for a total incidence rate of 0.8%. AAA sac growth of greater than 5 mm was observed in 20 patients (5.6%), four of whom have undergone successful catheter-based treatments to date. Overall, 39 patients (10.7%) needed catheter-based (n = 45) or limited surgical (n = 4) reinterventions for a variety of late problems that were successful in 92%. CONCLUSION: In our 7-year experience, one or more clinical failures of endovascular AAA repair were observed in 31 patients (8.3%). Reinterventions were necessitated in a total of 10.7% of patients but were usually successful in maintaining AAA exclusion and limiting AAA growth. These results emphasize that endovascular repair provides good results and many benefits for most properly selected patients but is not as durable as standard open repair.