Reduced primary patency rate in diabetic patients after percutaneous intervention results from more frequent presentation with limb-threatening ischemia

ObjectiveAlthough patients with diabetes are at increased risk of amputation from peripheral vascular disease, excellent limb-salvage rates have been achieved with aggressive surgical revascularization. It is less clear whether patients with diabetes will fare as well as nondiabetics after undergoing percutaneous lower extremity revascularization, a modality which is becoming increasingly utilized for this disease process. This study aimed to assess differential outcomes in between diabetics and nondiabetics in lower extremity percutaneous interventions.MethodsWe retrospectively studied 291 patients with respect to patient variables, complications, and outcomes for percutaneous interventions performed for peripheral occlusive disease between 2002 and 2005. Tibial vessel run-off was assessed by angiography. Patency (assessed arterial duplex) was expressed by Kaplan-Meier method and log-rank analysis. Mean follow-up was 11.6 months (range 1 to 56 months).ResultsA total of 385 interventions for peripheral occlusive disease with claudication (52.2%), rest pain (16.4%), or tissue loss (31.4%) were analyzed, including 336 primary interventions and 49 reinterventions (mean patient age 73.9 years, 50.8% male). Comorbidities included diabetes mellitus (57.2%), chronic renal insufficiency (18.4%), hemodialysis (3.8%), hypertension (81.9%), hypercholesterolemia (57%), coronary artery disease (58%), tobacco use (63.2%). Diabetics were significantly more likely to be female (55.3% vs 40.8%), and suffer from CRI (23.5% vs 12.0%), a history of myocardial infarction (36.5% vs 18.0%), and <three-vessel tibial outflow (83.5% vs 71.8%), compared with nondiabetics, although all other comorbidities and lesion characteristics were equivalent between these groups. Overall primary patency (± SE) at 6, 12, and 18 months was 85 ± 2%, 63 ± 3% and 56 ± 4%, respectively. Patients with diabetes suffered reduced primary patency at 1 year compared with nondiabetics. For nondiabetics, primary patency was 88 ± 2%, 71 ± 4%, and 58 ± 4% at 6, 12, and 18 months, while for diabetics it was 82 ± 2%, 53 ± 4%, and 49 ± 4%, respectively (P = .05). Overall secondary patency at 6, 12, and 18 months was 88 ± 2%, 76 ± 3%, and 69 ± 3%, and did not vary by diabetes status. One-year limb salvage rate was 88.3% for patients with limb-threatening ischemia, which was also similar between diabetics and nondiabetics. While univariate analysis revealed that female gender, <three-vessel tibial outflow, and a history of tobacco use were all predictive of reduced primary patency (P < .05), none of these factors significantly impacted secondary patency or limb-salvage rate. Furthermore, only limb-threatening ischemia remained a significant predictor of outcome on multivariate analysis, suggesting that the poorer primary patency in diabetics is related primarily to their propensity to present with limb-threatening disease compared with nondiabetics.ConclusionPatients with diabetes demonstrate reduced primary patency rates after percutaneous treatment of lower extremity occlusive disease, most likely due to their advanced stage of disease at presentation. However, despite a higher reintervention rate, diabetics and others with risk factors predictive of reduced primary patency can attain equivalent short-term secondary patency and limb-salvage rates. Therefore, these patient characteristics should not be considered contraindications to endovascular therapy

Evaluation of pressure transmission and intra-aneurysmal contents after endovascular repair using the Trivascular Enovus expanded polytetrafluoroethylene stent graft in a canine model of abdominal aortic aneurysm

ObjectiveEndotension has been defined as persistently increased pressure within the excluded sac of an abdominal aortic aneurysm (AAA) resulting in increasing aneurysm size after endovascular repair in the absence of endoleak. Devices that use expanded polytetrafluoroethylene (ePTFE) have been associated with the development of endotension and continued AAA enlargement. In this study, intra-aneurysmal pressure and aneurysm content were evaluated after endovascular repair with the Enovus ePTFE stent graft in a canine model.MethodsProsthetic ePTFE aneurysms, each containing a solid-state, strain-gauge pressure transducer, were implanted in the infrarenal aorta of 13 mongrel dogs (25-35 kg). A second pressure transducer was inserted into the native aorta for systemic arterial pressure measurement. The stent graft was then deployed to exclude the aneurysm via distal aortic access. Comparison was made among three distinct stent grafts: the Trivascular Enovus (nonporous ePTFE; four animals), the original Gore Excluder (porous ePTFE; five animals), and the Medtronic AneuRx (Dacron; four animals). Daily systemic and intra-AAA pressures were measured for 4 weeks. Intra-aneurysmal pressures were indexed to simultaneously measured systemic pressures. After 4 weeks, the aorta, the prosthetic aneurysm, and its contents were harvested, photographed, and processed for histologic investigation with hematoxylin and eosin and Masson trichrome staining.ResultsWithin 24 hours after exclusion, the mean arterial pressure and pulse pressure within the AAA sac tapered to less than 20% of systemic pressure for all three stent graft types. Throughout the postoperative period, significantly lower indexed intra-aneurysmal pressures were present in the Enovus- and AneuRx-treated aneurysms as compared with those treated with the original Excluder stent graft (0.05 ± 0.04, 0.16 ± 0.06, and 0.06 ± 0.03 for the Enovus, Excluder, and AneuRx, respectively). Histologic analysis of the Enovus-treated aneurysms demonstrated intraluminal content characterized almost entirely by erythrocytes and infrequent white blood cells without the fibrin organization—characteristics of acute or chronic thrombus. This contrasted with the content of the Excluder-treated aneurysms, which contained poorly organized fibrin deposition suggestive of acute thrombus, and of the AneuRx-treated aneurysms, which demonstrated mature, well-organized collagenous connective tissue.ConclusionsExclusion of the AAA with the Enovus stent graft resulted in nearly complete elimination of intra-aneurysmal pressure in this model. Histologic analysis of the aneurysm content further suggested complete exclusion, including elimination of circulating clotting factors and fibroblasts responsible for thrombus formation and reorganization. Ultimately, clinical evaluation will be necessary to demonstrate the effectiveness of this stent graft in preventing the development of endotension.Clinical RelevanceEndovascular aneurysm repair is an effective method for the treatment of abdominal aortic aneurysm (AAA) subjected to the unique complications of endoleak and endotension, the indirect pressurization of a sac in the absence of endoleak. In our model, AAA exclusion with the Enovus stent graft results in inhibition of fluid and serum transudation into the AAA sac, a corresponding prompt pressure decay profile, and near-complete elimination of intra-aneurysmal pressure. With the advent of implantable wireless pressure transducers, this research can be readily translated to the clinical setting. Future intraoperative and postoperative studies may help elucidate the clinical significance of pressure decay profiles in identifying successful AAA exclusion and monitoring for the development of endotension and its clinical sequelae

Percutaneous intervention for infrainguinal occlusive disease in women: equivalent outcomes despite increased severity of disease compared with men

Experience with open surgical bypass suggests similar overall outcomes in women compared with men, but significantly increased risk of wound complications. Percutaneous treatment of lower extremity occlusive disease is therefore an attractive alternative in women, although it is not clear whether there is a difference in outcomes between women and men treated with this technique. We sought to determine the results and predictors of failure in women treated by percutaneous intervention. Percutaneous infrainguinal revascularization was performed on 309 women between 2001 and 2006. Procedures, complications, demographics, comorbidities, and follow-up data were entered into a prospective database for review. Patency was assessed primarily by duplex ultrasonography. Outcomes were expressed by Kaplan-Meier curves and compared by log-rank analysis. A total of 447 percutaneous interventions performed in 309 women were analyzed and compared with 553 interventions in men. Mean age in women was 73.2 years; comorbidities included hypertension (HTN) (86%), diabetes melitus (DM) (58%), chronic renal insufficiency (CRI) (15%), hemodialysis (7%), hypercholesterolemia (52%), coronary artery disease (CAD) (42%), and tobacco use (47%). Indications in women included claudication (38.0%), rest pain (18.8%), and tissue loss (43.2%). Overall primary & secondary patency and limb-salvage rates for women were 38% +/- 4%, 66% +/- 3%, and 80% +/- 4% at 24 months. In this patient sample, women were significantly more likely than men to present with limb-threatening ischemia (61.6% vs 47.3%, P < 0.001) and have lesions of TASC C and D severity (71.4% vs 61.7%, P < .005). However, there were no significant differences in primary and secondary patency rates or limb-salvage rates between genders. Furthermore, while women with limb-threat, diabetes, and advanced TASC severity lesions were at increased risk of failure overall, there were no differences between women and men with these characteristics. Percutaneous infrainguinal revascularization is a very effective modality in women with lower extremity occlusive disease. Although women in this sample were more likely to present with limb-threat than men, patency and limb-salvage rates were equivalent between genders, even in high-risk subsets such as diabetics or those with lesions of increased TASC severity