Challenges and potential solutions to enrollment in a clinical trial of arteriovenous fistula vs arteriovenous graft vascular access strategy.

This article presents the rationale, challenges, and adaptive strategies employed during the initiation and execution of the arteriovenous (AV) access trial-a multicenter randomized controlled trial (RCT) comparing AV fistulas and AV grafts for hemodialysis in older adults with major comorbidities. Motivated by shifts in epidemiologic landscapes and evolving guidelines moving away from a fistula-first approach and to more patient-centric approaches, the objective of this randomized controlled trial was to fill critical knowledge gaps in determining the optimal vascular access for this complex patient population. We outline the challenges encountered in patient recruitment along with measures employed to overcome these obstacles in recruitment.

Aortobiiliac bypass to the distal external iliac artery versus aortobifemoral bypass: a matched cohort study.

Vascular bypass has long been the standard surgical treatment for symptomatic aortoiliac occlusive disease (AIOD). Conventional wisdom has been that aortobifemoral bypass (ABF) be performed for AIOD because of the inevitable progression of iliac atherosclerosis leading to bypass thrombosis. However, ABF is prone to significant groin incision complications such as infection and lymphocele.

Clinical success using patient-oriented outcome measures after lower extremity bypass and endovascular intervention for ischemic tissue loss.

Introduction: Successful outcome after lower extremity revascularization is usually measured by physician-oriented terms such as graft patency and amputation-free survival. It has been increasingly appreciated that these criteria do not necessarily translate into success from the prospective of the patient. The purpose of this study, therefore, is to retrospectively examine success after lower extremity revascularization for tissue loss using patient-oriented measures and to include patients who underwent both open surgical bypass and endovascular therapy.

Comparison of interventional outcomes according to preoperative indication: a single center analysis of 2,240 limb revascularizations.

Background: Outcomes after lower extremity revascularization are usually reported according to the level of peripheral arterial disease (PAD, aortoiliac or infrainguinal) or the method of treatment (open or endovascular surgery). Outcomes stratified by indication, ie, claudication or critical limb ischemia (rest pain and tissue loss), have not been well studied. The purpose of this study was to compare postoperative outcomes according to the preoperative indications.

The reverse J arteriovenous graft configuration for hemodialysis access: rationale, technique, and outcomes.

The long-term survival of patients on hemodialysis is often limited by the exhaustion of vascular access sites. A fundamental principle of vascular access surgery is that the arteriovenous (AV) access be placed as far distally in the arm as possible. This principle enhances the secondary patency of the AV grafts by preserving the proximal veins for AV graft revision and provides venous outflow for a new AV access to be placed more proximally in the extremity.

Contemporary outcomes of iliofemoral bypass grafting for unilateral aortoiliac occlusive disease: a 10-year experience.

Current treatment of complex aortoiliac occlusive disease (AIOD) includes the aortobifemoral bypass or the femoral-femoral bypass. However, because of bilateral groin exposure and associated risks, there is a significant morbidity associated with these procedures. In appropriate patients with unilateral AIOD, the iliofemoral bypass graft (IFBPG) via a lower abdominal retroperitoneal incision can be an acceptable alternative.

Do current outcomes justify more liberal use of revascularization for vasculogenic claudication? A single center experience of 1,000 consecutively treated limbs.

Background: The purpose of this study was to reconsider current recommended treatment guidelines for vasculogenic claudication by examining the contemporary results of surgical intervention.

Study Design: We performed a retrospective review of 1,000 consecutive limbs in 669 patients treated for medically refractory vasculogenic claudication and prospectively followed. Outcomes measured included procedural complication rates, reconstruction patency, limb salvage, maintenance of ambulatory status, maintenance of independent living status, survival, symptom resolution, and symptom recurrence.

Surgical implications of early failed endovascular intervention of the superficial femoral artery.

Background: It is generally accepted that failed infrainguinal bypass with prosthetic material significantly compromises arterial run off, which may limit future revascularization. It is well known that the negative consequences of early vein graft thrombosis are limited, but the effect of failed peripheral angioplasty on the distal vasculature is poorly studied. The purpose of this study was to determine whether early failure after superficial femoral artery intervention influences subsequent revascularization options.

Is surgical thrombectomy to salvage failed autogenous arteriovenous fistulae worthwhile?

The Dialysis Outcomes Quality Initiatives guidelines emphasize placement of autogenous arteriovenous (AV) fistulae for patients on hemodialysis. This recommendation is based on studies that demonstrate enhanced patency for AV fistulae compared with grafts. However, closer review of the data demonstrates that although primary patency of AV fistulae is superior to grafts, the secondary patency rates are equivalent.

The mid-thigh loop arteriovenous graft: patient selection, technique, and results.

As patient longevity on hemodialysis has increased, surgeons are increasingly challenged to provide vascular access to patients who have exhausted options for access in the upper extremity. A common operation performed on these patients has been the loop thigh arteriovenous (AV) graft based off the common femoral vessels. However, there are several disadvantages of placing prosthetic grafts in proximity to the groin.

Does obesity predict functional outcome in the dysvascular amputee?

Limited information is available concerning the effects of obesity on the functional outcomes of patients requiring major lower limb amputation because of peripheral arterial disease (PAD). The purpose of this study was to examine the predictive ability of body mass index (BMI) to determine functional outcome in the dysvascular amputee. To do this, 434 consecutive patients (mean age, 65.

Postoperative outcomes according to preoperative medical and functional status after infrainguinal revascularization for critical limb ischemia in patients 80 years and older.

The purpose of this study was to provide outcomes after intervention for critical limb ischemia (CLI) in elderly patients (> or =80 years) according to medical and functional status at presentation. From January 1998 to September 2003, 140 limbs/122 patients (age range 80-97 years) were treated (57 patients/66 limbs, infrainguinal bypass; 65 patients/74 limbs, infrainguinal angioplasty) for CLI. At presentation, 71 (58.

Uniqueness and nonuniqueness in the Einstein constraints.

The conformal thin-sandwich (CTS) equations are a set of four of the Einstein equations, which generalize the Laplace-Poisson equation of Newton's theory. We examine numerically solutions of the CTS equations describing perturbed Minkowski space, and find only one solution. However, we find two distinct solutions, one even containing a black hole, when the lapse is determined by a fifth elliptic equation through specification of the mean curvature.

Preoperative clinical factors predict postoperative functional outcomes after major lower limb amputation: an analysis of 553 consecutive patients.

Background: Despite being a major determinant of functional independence, ambulation after major limb amputation has not been well studied. The purpose, therefore, of this study was to investigate the relationship between a variety of preoperative clinical characteristics and postoperative functional outcomes in order to formulate treatment recommendations for patients requiring major lower limb amputation.

Methods: From January 1998 through December 2003, 627 major limb amputations (37.

Does a standardization tool to direct invasive therapy for symptomatic lower extremity peripheral arterial disease improve outcomes?

Objectives: While decision analysis and treatment algorithms have repeatedly been shown to improve quality of care in many areas of medicine, no such algorithm has emerged for the invasive management of lower extremity peripheral arterial disease. Using the best available evidence-based outcomes data, our group designed a standardization tool, the Lower Extremity Grading System (LEGS) score, which consistently directs limbs to a specific treatment on the basis of presentation. The purpose of this study was to examine whether use of such a tool improves outcomes by directing treatment of lower extremity peripheral arterial disease.

Invasive treatment of chronic limb ischemia according to the Lower Extremity Grading System (LEGS) score: a 6-month report.

Background: The invasive treatment of chronic lower extremity peripheral arterial disease (PAD) has become inconsistent. To standardize treatment at our institution, the Lower Extremity Grading System (LEGS) score was devised, based on arteriographic findings, symptoms, functional status, comorbid conditions, and technical factors. The scoring system was used to direct the invasive treatment approach in patients with lower extremity PAD.

Trends in aortic aneurysm surgical training for general and vascular surgery residents in the era of endovascular abdominal aortic aneurysm repair.

Hypothesis: The emergence of endovascular abdominal aortic aneurysm (AAA) repair may negatively impact the open AAA experience of general surgery residents.

Methods: Prospectively collected data on general and vascular surgery resident training in AAA repair for a 5-year period (1997 to 2001) at a single institution were retrospectively reviewed. Five general surgery residents and one vascular resident completed training yearly.

Endovascular exclusion of saccular AAAs using "stacked" AneuRx aortic cuffs.

Purpose: To show that AneuRx aortic cuffs might be used in a "stacked" configuration to effectively treat saccular abdominal aortic aneurysm (AAA).

Methods: In a recent 1-year period, 147 patients underwent endovascular AAA repair. Of these, 5 (4 men; mean age 61.

A decade of decline: an analysis of Medicare reimbursement for vascular surgical procedures.

Despite inflation and a robust economy, standard Medicare reimbursements for vascular surgical procedures have progressively declined. The objective of this analysis was to quantitatively and objectively evaluate the decline of vascular surgical reimbursement over the past decade. In this study, data for the analysis of specific vascular surgical procedures was obtained from the National Center for Health Statistics-National Hospital Discharge Survey (NCHS-NHDS) for all vascular procedures as reported by ICD-9-CM codes.

Aortic neck angulation predicts adverse outcome with endovascular abdominal aortic aneurysm repair.

Background: Significant aortic neck angulation may predispose to suboptimal outcome after endovascular abdominal aortic aneurysm (EAAA) repair. However, the definition of "significant" neck angulation and its correlation with adverse outcome are poorly characterized.

Methods: Prospectively collected data on 148 consecutive EAAA repairs performed between December 1995 and January 2001 were supplemented with retrospective review of charts and radiographs.

Prevention and management of ureteral injuries during aortic surgery.

Ureteral injury during aortic surgery may lead to life-threatening consequences. Unlike gynecologic or abdominal surgical procedures in which ureteral injuries more commonly occur, this type of iatrogenic injury may be particularly hazardous because of the presence of prosthetic graft material. Ureteral obstruction by extrinsic compression, from an anteriorly placed graft limb or retroperitoneal fibrosis, is the most commonly reported type of ureteral complication.

Development of oral heparin therapy for prophylaxis and treatment of deep venous thrombosis.

Objective: To review the current research and published literature regarding the development of oral heparin therapy for the prophylaxis and treatment of deep venous thrombosis.

Background: Currently, the accepted practice of prophylaxis and/or treatment of acute deep venous thrombosis (DVT) is intravenous or subcutaneous (SQ) heparin followed by oral warfarin or SC low molecular weight heparin (LMWH) therapy followed by warfarin. Both of which are less than ideal.

Comparison of open transabdominal AAA repair with endovascular AAA repair in reduction of postoperative stress response.

Operative intervention causes a necessary biologic response known as the hypermetabolic stress response. Less invasive operative procedures may cause fewer metabolic and endocrine derangements. To evaluate the metabolic and endocrine differences between endovascular and transperitoneal abdominal aortic aneurysm (AAA) repair, 10 patients underwent standard open repair (open group) and 10 patients underwent endovascular repair of AAA (endovascular group) with a modular bifurcated endograft.