Eric K. Peden

Impact of runoff on superficial femoral artery endoluminal interventions for rest pain and tissue loss

BACKGROUND While aggressive endoluminal therapy for superficial femoral artery (SFA) occlusive disease is commonplace, the implications of runoff on long-term outcomes of these interventions in patients with rest pain and tissue loss is unclear. Runoff is known to negatively effect graft patency. The aim of this study is to examine the impact of distal runoff on long-term outcomes of SFA interventions for critical ischemia. METHODS A prospective database of patients undergoing endovascular treatment of the SFA between 1986 and 2007 was queried. Patients with Rutherford symptom classification 4, 5, and 6 were selected. Patients with concomitant tibial interventions were excluded. Pre-operative angiograms were reviewed in all cases to assess distal popliteal and tibial runoff and were scored according to modified Society of Vascular Surgery criteria for both vessels such that a higher score implies worse runoff (minimum 1 and maximum 19). Three runoff score groups were identified: <5 (good), 5-10 (compromised), and >10 (poor). Kaplan-Meier survival analyses were performed to assess time-dependent outcomes. Multivariate and factor analyses were performed. RESULTS Three hundred six limbs in 241 patients (57% male, mean age 68 years) underwent endovascular treatment for critical ischemia (44% rest pain and 56% tissue loss.) Technical success was 96% with 61% SFA undergoing angioplasty, 37% SFA primary stenting and 2% SFA an atherectomy. Overall mortality was 1% and overall morbidity was 16% at 90 days after the procedure. At 5 years, vessels with compromised and poor runoff had significantly worse cumulative patency (82 +/- 9%, 56 +/- 4%, and 52 +/- 7% for good, compromised, and poor runoffs, respectively, mean +/- standard error of the mean [SEM]). Freedom from recurrent symptoms (65 +/- 8%, 39 +/- 9%, and 18 +/- 9% for good, compromised, and poor runoffs, respectively) and limb salvage (65 +/- 5%, 41 +/- 4%, and 20 +/- 6% for Good, Compromised, and Poor runoffs, respectively) were incrementally curtailed by worsening runoff with significant decreases as runoff category deteriorated. CONCLUSIONS In patients presenting with rest pain and tissue loss who are treated with SFA percutaneous interventions, patency is negatively affected by compromised and poor runoffs in keeping with the bypass literature. More importantly, freedom from recurrent symptoms and limb salvage are incrementally curtailed as runoff scores worsen. These findings are consistent with the bypass literature.

Initial experience and outcome of a new hemodialysis access device for catheter-dependent patients

OBJECTIVE The effects of a new long-term subcutaneous vascular access device were studied in access-challenged patients who were poor candidates for fistulas or grafts due to venous obstruction. Bacteremia rates, patency, and function of the Hemodialysis Reliable Outflow (HeRO) Vascular Access Device (Hemosphere Inc, Minneapolis, Minn) were evaluated. METHODS The HeRO device consists of a 6-mm expanded polytetrafluoroethylene graft attached to a 5-mm nitinol-reinforced silicone outflow component designed to bypass venous stenoses and enter the internal jugular vein directly, providing continuous arterial blood flow into the right atrium. The HeRO device was studied in a multicenter clinical trial to test the hypothesis that access-challenged patients would experience a statistically significant reduction in bacteremia rates compared with a tunneled dialysis catheter (TDC) literature control of 2.3/1000 days. HeRO-related bacteremia rates, adequacy of dialysis, patency, and adverse events were analyzed. RESULTS The HeRO device was implanted in 36 access-challenged patients who were followed for a mean 8.6 months (9931 HeRO days). The HeRO-related bacteremia rate was 0.70/1000 days. All HeRO-related bacteremias occurred during the bridging period when a TDC was still implanted before HeRO graft incorporation. HeRO adequacy of dialysis (mean Kt/V) was 1.7. HeRO primary patency was 38.9%, and secondary patency was 72.2%. CONCLUSIONS In access-challenged patients, a statistically significant reduction in HeRO-related bacteremia was noted compared with TDC literature. The device had similar function and patency compared with conventional arteriovenous graft literature.

Bioengineered human acellular vessels for dialysis access in patients with end-stage renal disease: two phase 2 single-arm trials

BACKGROUND For patients with end-stage renal disease who are not candidates for fistula, dialysis access grafts are the best option for chronic haemodialysis. However, polytetrafluoroethylene arteriovenous grafts are prone to thrombosis, infection, and intimal hyperplasia at the venous anastomosis. We developed and tested a bioengineered human acellular vessel as a potential solution to these limitations in dialysis access. METHODS We did two single-arm phase 2 trials at six centres in the USA and Poland. We enrolled adults with end-stage renal disease. A novel bioengineered human acellular vessel was implanted into the arms of patients for haemodialysis access. Primary endpoints were safety (freedom from immune response or infection, aneurysm, or mechanical failure, and incidence of adverse events), and efficacy as assessed by primary, primary assisted, and secondary patencies at 6 months. All patients were followed up for at least 1 year, or had a censoring event. These trials are registered with ClinicalTrials.gov, NCT01744418 and NCT01840956. FINDINGS Human acellular vessels were implanted into 60 patients. Mean follow-up was 16 months (SD 7·6). One vessel became infected during 82 patient-years of follow-up. The vessels had no dilatation and rarely had post-cannulation bleeding. At 6 months, 63% (95% CI 47-72) of patients had primary patency, 73% (57-81) had primary assisted patency, and 97% (85-98) had secondary patency, with most loss of primary patency because of thrombosis. At 12 months, 28% (17-40) had primary patency, 38% (26-51) had primary assisted patency, and 89% (74-93) had secondary patency. INTERPRETATION Bioengineered human acellular vessels seem to provide safe and functional haemodialysis access, and warrant further study in randomised controlled trials. FUNDING Humacyte and US National Institutes of Health.

The long-term outcomes of percutaneous therapy for renal artery fibromuscular dysplasia

BACKGROUND Percutaneous intervention for symptomatic renal artery fibromuscular dysplasia (FMD) has replaced surgical therapy as first-line treatment. This study evaluates the factors that impact long-term anatomic and functional outcomes of endovascular therapy for symptomatic renal artery FMD. METHODS Records of patients who underwent renal artery angioplasty for FMD between January 1990 and December 2007 were retrospectively analyzed. Indication for intervention was poorly controlled hypertension (diastolic blood pressure >90 mm Hg or systolic blood pressure >140 mm Hg, or both, taking >2 antihypertensive medications). Twenty-nine women (average age, 45 years [range, 18-80]; 86% with a history of hypertension <8 years) underwent 38 attempted interventions. Sixty-six percent of contralateral kidneys were normal (31% had a </=60% stenosis), 13% had >60% stenosis, and the remainder were nonfunctioning or absent. Creatinine was >1.5 mg/dL in 4%, 24% had hyperlipidemia, 17% had metabolic syndrome, and 4% were considered diabetic. OUTCOMES All interventions were successfully performed. Stent placement was required in 13% for technical failure and flow-limiting dissection. Seventy-three percent of these lesions were in the proximal renal artery, with the remainder in the middle renal artery. Technical success (<30% residual stenosis) was achieved in all vessels. There were no periprocedural or 90-day deaths. The procedurally related complication rate was 8%. Median follow-up was 2 years. All patients were alive at follow-up. Primary and assisted primary patency rates were 66% and 87% at 5 years. Restenosis was considered a 50% reduction in luminal area on angiography during follow-up. The restenosis rate was 28% at 5 years (10 vessels underwent repeat percutaneous intervention). Immediate clinical benefit was seen in hypertension in 72% (improved or cured </=3 months) and was maintained in 73% at 5 years by life-table analysis. Proportional hazard analysis showed the predictors of long-term clinical benefit were duration of hypertension <8 years, creatinine <1.5 mg/dL, ipsilateral kidney size >9 cm, functional status of the contralateral kidney, a fasting blood glucose <110 mg/dL, triglycerides <150 mg/dL, and high-density lipoprotein >50 mg/dL. Neither age <50 years nor statin administration appeared significant. CONCLUSIONS Percutaneous endovascular intervention for clinically symptomatic FMD in the renal arteries is technically successful, safe, and durable. Most patients have immediate clinical benefit, with continued long-term results out to 5 years. It appears that the presence of existing renal pathology and markers of prediabetic state are associated with recurrence of hypertensive symptoms.

Efficacy of covered stent placement for central venous occlusive disease in hemodialysis patients

OBJECTIVES Covered stents have been proposed as an endovascular option for recalcitrant cases of hemodialysis-related central venous occlusive disease (CVOD). This study evaluated the efficacy and durability of covered stents in treating CVOD to preserve a functional dialysis access circuit. METHODS A retrospective review was performed of all patients with clinically significant CVOD who were treated by placement of covered stents from April 2007 to September 2010. Demographics, lesion locations and anatomic characteristics, stent graft, and access patency rates were determined. Complications, reinterventions, and factors influencing their outcomes were examined. RESULTS In 25 patients (56% men; mean age, 57 ± 29 years) with CVOD, covered stents were used in 20 to treat symptomatic venous hypertension or in 5 at the time of access creation to enable functionality. The target lesion was accessed via the dialysis access site or the common femoral vein. The Viabahn endoprosthesis (W. L. Gore and Associates, Flagstaff, Ariz) was used in 24 patients (average size and length, 11 mm × 5 cm) and a 13-mm × 5-cm Fluency covered stent (Bard Peripheral Vascular, Tempe, Ariz) was implanted in 1 patient. Technical success was 100%, and resolution of arm edema occurred after covered stent deployment in symptomatic patients. Two postprocedural cases (8%) of thrombosis occurred, one within 30 days and another at 3 months. Both required percutaneous thrombectomy and percutaneous transluminal angioplasty (PTA). Three additional patients (12%) required PTA due to restenosis in one of the ends of the device. Covered stent primary patency (PP), assisted primary patency (APP), and secondary patency (SP) were 56%, 86%, and 100% at 12 months, respectively. Access patency rates at 12 months were 29%, 85%, and 94% for PP, APP, and SP, respectively, in patients that received a covered stent for access salvage; patency rates were 74%, 85%, and 94% for PP, APP, and SP, respectively, in patients in whom the access was created after the venous outflow restoration. CONCLUSIONS Placement of covered stents for hemodialysis-related CVOD is safe, effective in relieving symptoms, and enabled functionality of new dialysis access circuits. Further prospective and randomized studies are necessary to determine whether covered stents provide superior long-term results to those achieved with PTA and bare metal stents.

Medical and endovascular management of critical limb ischemia.

Critical limb ischemia (CLI) is the term used to designate the condition in which peripheral artery disease has resulted in resting leg or foot pain or in a breakdown of the skin of the leg or foot, causing ulcers or tissue loss. If not revascularized, CLI patients are at risk for limb loss and for potentially fatal complications from the progression of gangrene and the development of sepsis. The management of CLI requires a multidisciplinary team of experts in different areas of vascular disease, from atherosclerotic risk factor management to imaging, from intervention to wound care and physical therapy. In the past decade, the most significant change in the treatment of CLI has been the increasing tendency to shift from bypass surgery to less invasive endovascular procedures as first-choice revascularization techniques, with bypass surgery then reserved as backup if appropriate. The goals of intervention for CLI include the restoration of pulsatile, inline flow to the foot to assist wound healing, the relief of rest pain, the avoidance of major amputation, preservation of mobility, and improvement of patient function and quality of life. The evaluating physician should be fully aware of all revascularization options in order to select the most appropriate intervention or combination of interventions, while taking into consideration the goals of therapy, risk-benefit ratios, patient comorbidities, and life expectancy. We discuss the incidence, risk factors, and prognosis of CLI and the clinical presentation, diagnosis, available imaging modalities, and medical management (including pain and ulcer care, pharmaceutical options, and molecular therapies targeting angiogenesis). The endovascular approaches that we review include percutaneous transluminal angioplasty (with or without adjunctive stenting); subintimal angioplasty; primary femoropopliteal and infrapopliteal deployment of bare nitinol, covered, drug-eluting, or bioabsorbable stents; cryoplasty; excimer laser-assisted angioplasty; excisional atherectomy; and cutting balloon angioplasty.

Hybrid thoracic endovascular aortic repair: Pushing the envelope

OBJECTIVE Thoracic endovascular aortic repair (TEVAR) can be limited by inadequate proximal and distal landing zones. Debranching or hybrid TEVAR has emerged as an important modality to expand landing zones and facilitate TEVAR. We report a single-center experience with hybrid TEVAR. METHODS We retrospectively reviewed all patients with thoracic aortic disease who received a TEVAR between February 2005 and October 2008. RESULTS Forty-two patients underwent a hybrid procedure (mean age 68 +/- 13 years; 55% men). All patients were denied open surgery due to preoperative comorbidities or low physiologic reserve; 62% had a history of coronary artery disease, 67% had chronic obstructive pulmonary disease, 61% had undergone prior aortic surgery, and 90% had an American Society of Anesthesiology score of 4 and above. The average Society for Vascular Surgery comorbidity score was 12 +/- 2 with a range of 9 to 14. Fifty-five percent of cases were symptomatic on presentation and 83% were done emergently. Seventy-six percent underwent debranching of the aortic arch, 17% of the visceral vessels, and 7% required both. Primary technical success was achieved in all cases and of these, 43% were staged. The 30-day mortality was 5%. Myocardial infarction developed in 5%, respiratory failure in 31%, cerebrovascular accident (stroke or transient ischemic attack) in 19%, and spinal cord ischemia with ensuant paraplegia occurred in 5% of patients. Fifty-eight percent of patients were discharged home, 11% required rehabilitation, and 29% were transferred to a skilled nursing facility. There was a significant association between visceral vessel debranching and both spinal cord ischemia (P = .004) and gastrointestinal complications (P = .005). On the other hand, there was no difference between staged and non-staged hybrid procedures. CONCLUSIONS Hybrid procedures can successfully extend the range of patients suitable for a subsequent TEVAR. These procedures are associated with higher complication rates than isolated infrarenal or thoracic endovascular repair, but given the medical and anatomical complexity of these patients, the current results are quite encouraging.

Ultrasound-guided percutaneous ablation for the treatment of perforating vein incompetence

Recent advances in catheter-based endovenous interventions have broadened our understanding in the pathophysiology and therapeutic strategies of chronic venous insufficiency, a condition that can be caused by abnormality of various lower extremity venous structures, including superficial or deep vein reflux or incompetent perforating veins. This article reviews the history and therapeutic principles of percutaneous ablation of perforators (PAPs). Discussions related to treatment strategies and procedural techniques of PAPs using radiofrequency ablation, laser energy, and sclerosant injection are provided. Current clinical results of PAPs with radiofrequency and laser energy ablation as a treatment modality of chronic venous insufficiency are also discussed.

Surgical management of hemodialysis-related central venous occlusive disease: A treatment algorithm

BACKGROUND Creation and preservation of dialysis access in patients with central venous occlusive disease (CVOD) is a complex problem. The surgical approach and decision-making process remains poorly defined. We evaluated our experience in the surgical management of hemodialysis-related CVOD. Surgical technique, demographics, complications, reinterventions, access function rates, and factors influencing morbidity and mortality were examined. METHODS From January 2006 to May 2010, we performed a total of 1,703 dialysis access-related procedures, 1,021 arteriovenous fistulas (AVFs), 335 arteriovenous grafts (AVGs), and 314 access revisions including endovascular salvage procedures. Seventeen patients (10 women [58%] with a mean age of 44 ± 27 years) with CVOD who were not suitable for peritoneal dialysis or kidney transplant underwent 20 complex vascular access procedures. The indications were need for access creation in 14 cases (70%) and preservation in the remaining 6 (30%). Polytetrafluoroethylene (PTFE) was used for all surgical bypass grafts (BPG). All patients had previously undergone multiple access surgeries and had failed percutaneous interventions for CVOD. RESULTS The surgical planning centered on finding venous outflow for an arteriovenous (AV) access; central venous reconstructions were necessary in 10 (50%) cases (seven [35%] in the thoracic central venous system and three [15%] in infradiaphragmatic vessels) and extracavitary venous BPG in two (10%) cases. Non-venous access options included axillary arterial-arterial chest wall BPG in five (25%) cases and brachial artery to right atrium BPG in three (15%). Technical success was achieved in all cases (100%). Mean follow-up was 14.1 months, both BPG and AV access patency rates were 66% at 6 months and overall average AV access function time was 9.2 months. Of these, 85% of patients were discharged home and following 19 (95%) cases they returned or improved their baseline functional status. One death occurred from multiorgan failure during the 30-day postoperative period. Four additional patients died within 3 years of the procedure secondary to nonsurgical-related comorbidities. CONCLUSION The need for complex vascular accesses will continue as the number of patients with end-stage renal disease increases. CVOD is an access surgical challenge and with this article we propose a decision-making algorithm.

Percutaneous superficial femoral artery interventions for claudication--does runoff matter?

Endoluminal therapy for superficial femoral artery (SFA) occlusive disease for claudication is commonplace, but the implications of tibial vessel runoff on long-term outcomes of these interventions in patients with claudication are unclear. Runoff is known to negatively affect graft patency, but no data are available on the impact of runoff on percutaneous SFA interventions and their implications during follow-up. We examined the impact of distal popliteal and tibial runoff on long-term outcomes of SFA interventions for claudication. A prospective database of patients undergoing endovascular treatment of the SFA between 1986 and 2007 was queried. Patients with Rutherford symptom classifications 1, 2, and 3 were selected; those with concomitant tibial interventions were excluded. Angiograms were reviewed preoperatively in all cases to assess distal popliteal and tibial runoff and scored according to modified Society for Vascular Surgery criteria for both vessels such that a higher score implies worse runoff (minimum 1, maximum 19). Three run-off score groups were identified: <5 (good), 5-10 (compromised), and >10 (poor). Kaplan-Meier survival analyses were performed to assess time-dependent outcomes. Multivariate and factor analyses were performed. There were 481 limbs in 347 patients (70% male, average age 66 years) that underwent endovascular SFA treatment for claudication: 87% had hypertension, 51% had diabetes mellitus, 67% had hyperlipidemia, and 16% had chronic renal insufficiency (1% on hemodialysis). Technical success was 92%, with 63% SFA undergoing angioplasty, 26% SFA undergoing primary stenting, and 3% SFA undergoing atherectomy. Overall mortality was 1.1% and overall morbidity was 17% at 90 days after the procedure. At 5 years, vessels with compromised and poor runoff had significantly lower freedom from recurrent symptoms and lower freedom from restenosis. Primary and assisted primary patency rates were significantly worse in patients with poor runoff. However, secondary patency was equivalent between the groups. Compromised or poor runoff was associated with incremental lower limb salvage. Following SFA percutaneous interventions for claudication, runoff can identify patients more likely to develop restenosis and recurrent symptoms and, more importantly, those at higher risk of limb loss. Defining such subgroups allows a clear risk stratification of patients with claudication and can guide the intensity of surveillance in the outpatient setting.