Technical and patient-related characteristics associated with challenging retrieval of inferior vena cava filters.

OBJECTIVE: To identify patient-related and device-specific predictors of challenging and failed inferior vena cava (IVC) filter retrievals. METHODS: Retrospective single center review of consecutive retrievable IVC filters placed between 2004 and 2009. Retrieval was defined as challenging when it was unsuccessful owing to reported technical failure or when adjunctive endovascular maneuvers or access sites were recruited. Data regarding patient- and filter-specific information were collected. Logistic regression models were used to identify predictors of the reported outcomes. Statistical significance was set at p < .05. RESULTS: Four hundred and one patients underwent retrievable IVC filter placement-the majority indicated for prophylaxis (67%). Two hundred and fifty-nine retrievals were attempted and 237 filters were successfully retrieved (overall retrieval rate: 59.1%). Eleven out of 259 (4.2%) attempts were aborted owing to significant thrombus within the filter and 11 (4.2%) were technically unsuccessful. In 142 patients no attempt for filter retrieval was made-the major reason being physician oversight (44.3%). Thirty-eight out of 248 (15.3%) non-aborted filter retrievals were recorded as challenging. Failed retrievals were predicted by prolonged dwell time (96.9 ± 111.9 vs. 29.5 ± 25.1 days, odds ratio [OR] 1.034, 95% confidence interval [CI] 1.016-1.053, p < .001), therapeutic indication (OR 5.197, 95% CI 1.200-22.511, p = .028), and filter wall apposition (OR 11.857, 95% CI 2.069-67.968, p = .006). Challenging retrievals were predicted by dwell time (51.1 ± 69.8 vs. 29.1 ± 24.5 days, OR 1.017, 95% CI 1.005-1.029, p = .007), filter tilt (OR 2.607, 95% CI 1.045-6.508, p = .040) and filter wall apposition (OR 6.149, 95% CI 2.398-15.763, p = <.001). CONCLUSIONS: Physician oversight leads to poor IVC filter retrieval rates. Retrievals can be challenging or fail when the dwell time is >50 days and >90 days, respectively, and when the filter hook apposes the caval wall. Filter tilt increases retrieval difficulty but not failure rates.

Cryoplasty offers no advantage over standard balloon angioplasty for the treatment of in-stent stenosis.

In-stent restenosis is the primary failure mode of endovascular treatment of occlusive disease in the femeropopliteal segment. Cryoplasty has been proposed to reduce intimal hyperplasia through induction of apoptosis. We sought to evaluate the efficacy of cryoplasty for treatment of in-stent restenosis compared to conventional balloon angioplasty (CBA). After IRB approval, a retrospective record review was performed of reinterventions for in-stent restenosis by a single vascular surgery group at a university hospital. Reinterventions involving cryoplasty and CBA were evaluated at 1, 3, 6 and 12 months after intervention with duplex imaging to identify significant recurrent stenosis utilizing established velocity criteria. Data collected included basic demographic information and comorbidities as well as time to restenosis. Statistical analysis was performed using Kaplan­Meier survival curves with the log rank test, Wilcoxon rank test, and Cox proportional hazards models. From December 2004 to November 2007, 76 reinterventions were performed using CBA (n = 39) or cryoplasty (n = 37) for in-stent restenosis without placement of additional stents. Periprocedural technical success (>30% residual stenosis) was 100% for both groups, with no complications. The two cohorts were statistically similar in mean age, gender, comorbidities, tobacco use and use of statins, aspirin and Plavix. However, the mean lesion length was significantly longer in the cryoplasty cohort (CBA: 140.9 mm, Cyro: 191.7 mm; P = 0.032). The mean time to recurrent stenosis or need for additional secondary intervention was significantly shorter for the cyroplasty cohort than for the CBA, 4.09 and 10.79 months, respectively (P = .0001). Recurrent stenosis-free survival was significantly lower in the cyroplasty cohort at 3 months (CBA: 96.9%, Cyro: 88.9%) and 6 months (CBA: 84.0%, Cyro: 43.8%; P = .0089). Cyroplasty as a modality for treatment of in-stent stenosis in the femoropopliteal segment offers no benefit over CBA.

Carotid artery stenosis: what is left to surgery.

While carotid angioplasty and stenting has been clearly established as a minimally invasive alternative to endarterectomy for patients with carotid occlusive disease, its indications continue to evolve, being refined as more controlled data of large studies are being accumulated. The purpose of this article is to review the current evidence supporting the application of either technique in certain subsets of patients, and the relative contraindications for their use.

The Gore Excluder endograft device for the treatment of abdominal aortic aneurysms.

UNLABELLED: Open surgical repair on abdominal aortic aneurysms has been performed for many years with good RESULTS: Despite the many advances in medical care, the procedure is still associated with many complications. The Gore Excluder endograft is a third-generation endograft that became the third commercially available endograft approved in the United States. Data from multiple trials have compared the use of the Excluder endograft to open repair and have shown favorable RESULTS: This review shall summarize the clinical use of the Excluder endograft from its initial clinical trial in 1998 to its current commercial use.

The aneurysm detection and management study screening program: validation cohort and final results. Aneurysm Detection and Management Veterans Affairs Cooperative Study Investigators.

BACKGROUND: We previously reported the prevalence and associations of abdominal aortic aneurysm (AAA) in 73451 veterans aged 50 to 79 years who underwent ultrasound screening. OBJECTIVE: To understand the prevalence of and principal positive and negative risk factors for AAA, and to assess reproducibility of our previous findings. METHODS: In the new cohort of veterans undergoing screening, 52 745 subjects aged 50 to 79 without history of AAA underwent successful ultrasound screening for AAA, after completing a questionnaire on demographics and potential risk factors. RESULTS: We detected AAA of 4.0 cm or larger in 613 participants (1.2%; compared with 1.4% in the earlier cohort). The direction and magnitude of the important associations reported in the first cohort were confirmed. Respective odds ratios for the major associations with AAA for the second and for the combined cohorts were as follows: 1.81 and 1.71 for age (per 7 years), 0.12 and 0. 18 for female sex, 0.59 and 0.53 for black race, 1.94 and 1.94 for family history of AAA, 4.45 and 5.07 for smoking, 0.50 and 0.52 for diabetes, and 1.60 and 1.66 for atherosclerotic diseases. The excess prevalence associated with smoking accounted for 75% of all AAAs of 4.0 cm or larger in the total population of 126 196. Associations for AAA of 3.0 to 3.9 cm were similar but tended to be somewhat weaker. CONCLUSIONS: Our findings confirm our previous cohort findings. Age, smoking, family history of AAA, and atherosclerotic diseases remained the principal positive associations with AAA, and female sex, diabetes, and black race remained the principal negative associations.

Yield of repeated screening for abdominal aortic aneurysm after a 4-year interval. Aneurysm Detection and Management Veterans Affairs Cooperative Study Investigators.

BACKGROUND: Little is known about the rate at which new abdominal aortic aneurysms (AAAs) develop or whether screening older men for AAA, if undertaken, should be limited to once in a lifetime or repeated at intervals. METHODS: A large population of veterans, aged 50 through 79 years, completed a questionnaire and underwent ultrasound screening for AAA. Of these, 5151 without AAA on the initial ultrasound (defined as infrarenal aortic diameter of 3.0 cm or larger) were selected randomly to be invited for a second ultrasound screening after an interval of 4 years. Local records and national databases were searched to identify deaths and AAA diagnoses made during the study interval in subjects who did not attend the rescreening. RESULTS: Of the 5151 subjects selected for a second screening, 598 (11.6%) had died (none due to AAA), and 20 (0.4%) had an interim diagnosis of AAA. A second screening was performed on 2622 (50.9%), of whom 58 (2.2%; 95% confidence interval, 1.6%-2.8%) had new AAA. Three new AAAs were 4.0 to 4.9 cm, 10 were 3.5 to 3.9 cm, and 45 were 3.0 to 3.4 cm. Independent predictors of new AAA at the second screening included current smoker (odds ratio, 3.09; 95% confidence, 1.74-5.50), coronary artery disease (odds ratio, 1.81; 95% confidence interval, 1.07-3.07), and, in a separate model using a composite variable, any atherosclerosis (odds ratio, 1.97; 95% confidence interval, 1.16-3.35). Adding the interim and rescreening diagnosis rates suggests a 4-year incidence rate of 2.6%. Rescreening only in subjects with infrarenal aortic diameter of 2.5 cm or greater on the initial ultrasound would have missed more than two thirds of the new AAAs. CONCLUSIONS: A second screening is of little practical value after 4 years, mainly because the AAAs detected are small. However, the incidence that we observed suggests that a second screening after longer intervals (ie, more than 8 years) may provide yields similar to those seen in initial screening and therefore warrants further study.

Transcutaneous oxygen measurements in lower extremity ischemia: effects of position, oxygen inhalation, and arterial reconstruction.

Transcutaneous oxygen tension (TcPO2) measurement has been successfully applied to the diagnosis and monitoring of patients with peripheral arterial insufficiency. This study was performed to assess the effects of changes in limb position, oxygen inhalation, and arterial reconstruction on TcPO2 values in patients with peripheral vascular disease. In addition, a TcPO2 index (foot TcPO2/chest TcPO2) was compared with the Doppler-derived ankle-to-brachial index (ABI) to determine which was the more effective monitor of the response to revascularization. Foot TcPO2 values of 22 patients with claudication or rest pain were measured before and after vascular reconstruction. TcPO2 increased after revascularization in both groups regardless of limb position or oxygen (O2) administration. The dependent position and O2 inhalation had an additive effect on TcPO2. Preoperative TcPO2 values in patients with rest pain showed the greatest response to the dependent position, increasing from 14 mm Hg to 33 mm Hg at room air and from 21 mm Hg to 53 mm Hg with O2 inhalation. TcPO2 in both patient groups was remarkably enhanced by O2 administration after revascularization. Postoperative supine TcPO2 values measured at room air increased from 50 mm Hg to 124 mm Hg (148%) in patients with claudication and from 40 mm Hg to 109 mm Hg (173%) in patients with rest pain after O2 inhalation. Comparison of the TcPO2 index with the ABI showed that absolute and normalized TcPO2 values are equally effective in monitoring peripheral arterial insufficiency. This study suggests that placing the limb in the dependent position and administering O2 may augment TcPO2 to levels where symptoms may resolve. The response of TcPO2 to O2 inhalation may be an indicator that reflects the response to revascularization.

General surgery in adult hemophiliacs.

From 1976 to 1984, 23 operations were performed on 22 patients with hemophilia (18 patients with factor VIII and four with factor IX deficiency). Elective procedures included resection of abdominal aortic aneurysm, liver transplantation, vagotomy/pyloroplasty, insertion of Mousseau-Barbin tube, colectomy, cholecystectomy, inguinal herniorrhaphy (four patients), colonoscopy/polypectomy, mediastinoscopy, arteriovenous fistula for dialysis, anal fistulectomy, and miscellaneous skin and soft-tissue procedures (five patients). Emergency operations were appendectomy (two patients), repair of bleeding liver biopsy site, and repair of an incarcerated inguinal hernia. There were two deaths (9%) within 30 days of operation, neither directly caused by the coagulopathy. Four patients had bleeding after surgery, which was treated with additional cryoprecipitate or factor concentrate. There were no nonhemorrhagic complications. Before operation, appropriate replacement therapy with factor VIII concentrate, cryoprecipitate, or fresh-frozen plasma was provided. Coagulation factor levels were measured before operation and monitored daily after operation. Generally, factor levels were raised to at least 1.0 U/ml and maintained at greater than 0.5 U/ml for 7 to 14 days after operation. However, when patients were treated with fresh-frozen plasma, plasma exchange was performed and factor levels of approximately 0.35 U/ml were achieved before surgery. We conclude that operations in patients with hemophilia can be accomplished safely with careful monitoring of coagulation factor levels and appropriate replacement therapy.

Cardiac risk in vascular surgery. The oral dipyridamole-thallium stress test.

The value of the oral dipyridamole-thallium stress test in identifying patients at high risk of myocardial infarction after vascular procedures has not been documented. We studied prospectively 46 patients who underwent an oral dipyridamole-thallium stress test before undergoing vascular operations. Twenty patients (43%) had a positive test result, defined by a thallium defect with reperfusion, while 26 patients had a negative test result. Myocardial infarctions were documented postoperatively in 5 (25%) of 20 of the group with positive results and 1 (4%) of 26 of the group with negative results. Three of the six myocardial infarctions were clinical; all three were in the group with positive results. No correlation was identified between dipyridamole-thallium stress test results and clinical cardiac history. A positive dipyridamole-thallium stress test result is a more sensitive predictor of postoperative myocardial infarction than ejection fraction or history of coronary artery disease. The oral dipyridamole-thallium stress test is as useful as the intravenous test in this setting.

The effect of arm exercise on regional cerebral blood flow in the subclavian steal syndrome.

Reversed vertebral blood flow distal to a subclavian obstruction is not uncommon and rarely leads to stroke. A small subgroup of these patients have obstruction in other portions of the extracranial or intracranial circulation, however, and cerebrovascular symptoms are induced by arm exercise, which may decrease regional cerebral blood flow--at times to critical levels--indicating a true "steal" syndrome. We evaluated six patients with symptomatic subclavian steal syndrome using stable xenon with computed tomography cerebral blood flow mapping. A decrease in flow from 13% to 90% in one or more regional vascular territories was found after arm exercise. Patients with a true "steal" syndrome may be at higher risk for stroke. Measuring regional cerebral blood flow may be a means of detecting patients who have a critical loss of flow reserves and who will be symptomatically improved by cerebral revascularization.

Arterial thromboembolic events in patients with the factor V Leiden mutation.

BACKGROUND: The factor V Leiden mutation affects 6% of the United States population and is known to be associated with venous thrombosis. We identify, herein, 30 individuals with the Leiden mutation and known arterial thromboembolic events. METHODS: The factor V mutation was assessed using polymerase chain reaction. RESULTS: In the 16 patients sustaining a cerebrovascular accident, the mean age was 44.1 and 11 (69%) were younger than 50. Similarly, the 13 patients presenting with an acute myocardial infarction were relatively young with a mean age of 45.5, and 9 (65%) patients presented at less than 50 years of age. Radiographic information was available for 19 patients in this study. No significant arterial atherosclerotic disease was demonstrated in 18 (95%) of these patients. CONCLUSIONS: This study demonstrates an association between the factor V Leiden mutation and the development of unexplained arterial thromboembolic events, especially in younger patients without existing atherosclerotic disease.

Oxygen-dependent chronic obstructive pulmonary disease does not prohibit aortic aneurysm repair.

BACKGROUND: Severe oxygen-dependent chronic obstructive pulmonary disease (COPD) is considered by many to be a contraindication to open abdominal aortic aneurysm (AAA) repair. We reviewed our own experience with this patient population. METHODS: From July 1995 to March 1999, 14 consecutive patients limited by home oxygen-dependent COPD underwent elective open infrarenal AAA repair. Their medical records were reviewed. RESULTS: The mean aortic aneurysm size was 6.3 cm. The mean PaO2 = 70 mm Hg, PaCO2 = 45 mm Hg, forced expiratory volume in 1 second (FEV1) = 34% of predicted, and forced vital capacity (FVC) = 67% of predicted. All 14 patients were extubated within 24 hours, mean length of hospital stay was 5.9 days, and there were no perioperative deaths. CONCLUSIONS: Severe home oxygen-dependent COPD is not a contraindication to safe elective open AAA repair.

Oxygen diffusion in chronic venous ulceration.

A diffusion barrier to oxygen caused by fibrin deposition around dilated, proliferating capillaries in patients with venous hypertension may contribute to the development of venous ulceration. This diffusion barrier was studied in 18 patients with venous ulcers using the transcutaneous oxygen (TcPO2) monitor (TCM204 Radiometer, America). TcPO2 sensors were placed adjacent to venous ulcers on lower limbs and on the chest and foot of each patient. Readings were taken after a sensor temperature of 44 degrees C was reached (10-15 minutes). TcPO2 values were markedly decreased in skin adjacent to the ulcers (10 +/- 2 mmHg) compared with those of the chest (64 +/- 2 mmHg) and foot (43 +/- 2 mmHg). Inhalation of 100% oxygen for 10 minutes increased chest TcPO2 in all patients (145 +/- 8 mmHg) and increased TcPO2 in skin around the ulcers in 17 of 18 patients (61 +/- 13 mmHg). This study supports the existence of a local pathologic barrier to oxygen diffusion in patients with venous ulcers.

The management of aortoenteric and paraprosthetic fistulae.

Aortoenteric and aortic paraprosthetic fistulae are devastating complications. Most authors recommend total excision of the graft and revascularization of the lower extremities by extra-anatomic bypass. We reviewed the University of Pittsburgh experience with these fistulae in 15 patients between 1977 and 1987. There were 9 aortoenteric fistulae (AEF) and 6 paraprosthetic fistulae (PPF). Seven of the 9 AEF had no abscess surrounding the graft, but communication of the intestine with the aortic anastomosis. One patient died during operation. Six patients underwent a local repair or in situ replacement of the graft. All 6 of those patients survived operation without limb loss. Two of the 9 patients with AEF had evidence of graft infection and underwent total excision of the graft and extra-anatomic reconstruction. Both patients died, one of sepsis and one of aortic stump rupture. All 6 patients with PPF had clinical and operative evidence of overt graft infection and underwent total graft excision and extra-anatomic bypass. Two of these patients died secondary to sepsis. We conclude that AEF, without evidence of graft infection, were safely treated by local repair. Patients with PPF had infected grafts requiring graft removal with significant morbidity and mortality.

Bilateral subclavian steal syndrome through different paths and from different sites--a case report.

Cases of cerebro-subclavian steal syndrome have been reported in the medical literature since 1960. This most often occurs on the left side because of the higher rate of involvement of the left subclavian artery in comparison to the other brachiocephalic branches of the aortic arch. With the use of the internal mammory artery as a conduit for coronary artery bypass, in the past three decades increasing numbers of coronary-subclavian steal in addition to the cerebro-subclavian steal have been observed. The authors report a case of bilateral subclavian steal syndrome through both vertebral arteries, the right common carotid artery, and the left internal mammory artery, without significant signs and symptoms of cerebral ischemia or anginal pain.

Is color-flow duplex a good diagnostic test for detection of isolated calf vein thrombosis in high-risk patients?

Color-flow duplex scanning (CDS) is a good diagnostic test for lower extremity proximal deep vein thrombosis (DVT). This report aims to evaluate the diagnostic accuracy of CDS in detecting isolated calf DVT in two in-hospital populations. A total of 166 patients had routine DVT testing with both CDS and venography: 99 total joint arthroplasty patients and 67 symptomatic in-hospital patients. Isolated calf DVT was noted in 34% of arthroplasty patients and 12% of symptomatic in-hospital patients. Peroneal DVT was most common. The sensitivity, specificity, positive predictive value, and negative predictive value (with 95% confidence interval [CI]) of CDS in detecting isolated calf DVT in the symptomatic in-hospital group was 39% (16%-62%), 98% (94%-99%), 88% (65%-99%), and 81% (71%-91%), respectively. In the arthroplasty patients these values were 13% (3%-23%), 92% (85%-99%), 60% (30%-90%), and 55% (45%-65%), respectively. CDS has a low sensitivity in detecting isolated calf DVT among hospitalized patients and cannot be deemed an effective tool for identifying clots limited to only one or two tibial vessels.

The Ancure endografting system: an update.

The Ancure endografting system (Guidant Cardiac and Vascular Division, Menlo Park, Calif) features a unibody, nonsupported woven polyester graft designed to treat abdominal aortic aneurysms. It is constructed in tube, bifurcated, and aortoiliac configurations. The attachment system consists of a frame with four independent V-shaped double hooks that penetrate the arterial wall for fixation. There are separate attachment systems at the proximal and distal ends of the endoprosthesis. In September 1999, the Food and Drug Administration (FDA) approved the tube and bifurcated devices for general use. The aortoiliac device is under present consideration of the FDA. Phase II and III clinical trials of the system enrolled over 870 patients from the end of 1995 to the summer of 1999. The device was deployed successfully in 90% to 96% of cases, depending on the configuration and the phase of the trial. Mortality rates were similar to those of concurrent open surgical control rates, but serious morbidity was reduced. Long-term follow-up of the bifurcated group from phase II showed only one migration and no ruptures. Aneurysm size reduction in this group was noted in 51.3% of patients at 1 year and 68.5% at 2 years. In the same subset, type I endoleaks were noted in 2.7% at 1 year and 1.3% at 2 years. All postoperative imaging studies were reviewed by a core laboratory facility. The advantages of the ancure system include solid fixation, flexibility in accommodating morphologic changes, and excellent long-term clinical performance. The disadvantages include a large introducer system and the potential for limb obstruction by compression or angulation. However, limb compromise responds well to intraluminal stenting. The expected FDA approval of the aortoiliac device and a larger variety of graft sizes should expand the number of patients who can be treated with this system.