Spinal cord injury after thoracic endovascular aortic aneurysm repair.

PURPOSE: Thoracic endovascular aortic aneurysm repair (TEVAR) has become a mainstay of therapy for aneurysms and other disorders of the thoracic aorta. The purpose of this narrative review article is to summarize the current literature on the risk factors for and pathophysiology of spinal cord injury (SCI) following TEVAR, and to discuss various intraoperative monitoring and treatment strategies. SOURCE: The articles considered in this review were identified through PubMed using the following search terms: thoracic aortic aneurysm, TEVAR, paralysis+TEVAR, risk factors+TEVAR, spinal cord ischemia+TEVAR, neuromonitoring+thoracic aortic aneurysm, spinal drain, cerebrospinal fluid drainage, treatment of spinal cord ischemia. PRINCIPAL FINDINGS: Spinal cord injury continues to be a challenging complication after TEVAR. Its incidence after TEVAR is not significantly reduced when compared with open thoracoabdominal aortic aneurysm repair. Nevertheless, compared with open procedures, delayed paralysis/paresis is the predominant presentation of SCI after TEVAR. The pathophysiology of SCI is complex and not fully understood, though the evolving concept of the importance of the spinal cord's collateral blood supply network and its imbalance after TEVAR is emerging as a leading factor in the development of SCI. Cerebrospinal fluid drainage, optimal blood pressure management, and newer surgical techniques are important components of the most up-to-date strategies for spinal cord protection. CONCLUSION: Further experimental and clinical research is needed to aid in the discovery of novel neuroprotective strategies for the protection and treatment of SCI following TEVAR.

Outcomes of intervention for cephalic arch stenosis in brachiocephalic arteriovenous fistulas.

BACKGROUND: Development of recalcitrant stenotic lesions of the cephalic arch is a significant cause of dysfunction of brachiocephalic access arteriovenous fistulas (AVFs). Endovascular and surgical therapy can be used to treat cephalic arch stenosis. The aim of this study was to evaluate the outcomes of endovascular and surgical interventions for cephalic arch stenosis. METHODS: A retrospective review of all patients during a 16-year period with a compromised but not occluded brachiocephalic AVF due to cephalic arch stenosis was undertaken. Patency, reintervention, infection, and functional dialysis rates were examined. RESULTS: From January 2000 to December 2015, 219 patients (67% female; mean age, 58 ± 20 years) with a failing brachiocephalic AVF underwent intervention at the cephalic arch. These interventions included angioplasty, primary stent placement, transposition, and bypass. The average time to intervention for cephalic arch stenosis was 1.7 years after primary access placement. The average number of percutaneous interventions before the decision to intervene surgically on the cephalic arch was three (range, two to six). Technical success was superior in the surgical groups (70% and 80% compared with 96% and 100% for balloon angioplasty, stenting, transposition, and bypass, respectively; P = .02). Major adverse cardiovascular events were overall low but significantly higher in the surgical groups (1%, 1%, 0.3%, and 0.3% for transposition, bypass, balloon angioplasty, and stenting, respectively; P = .02). Both surgical options carried significantly superior patency rates at 2 years for transposition, bypass, balloon angioplasty, and stenting, respectively (63%, 59%, 90%, and 92%; P = .04). There was a lower rate of interventions per person-year of follow-up in the surgical groups compared with the endovascular groups (1.9, 1.4, 3.5, and 3.1 for transposition, bypass, balloon angioplasty, and stenting, respectively; P = .04). Functional dialysis durations were significantly superior in the surgical groups compared with the endovascular group (P = .03). CONCLUSIONS: Cephalic arch stenosis is a significant cause of brachiocephalic AVF malfunction. Surgical options offer superior long-term patency and functional results and should be considered earlier in the treatment of this disease.

"In situ" endografting in the treatment of arterial and graft infections.

OBJECTIVE: Endografts (eg, aortic aneurysm device or covered stent) are increasingly being used to temporize or treat arterial and graft infections in inaccessible areas, in patients with compromised anatomy, or in the presence of active bleeding or rupture. This summary examines the evidence for "in situ" endografting in the treatment these conditions. METHODS: A two-level search strategy of the literature (MEDLINE, PubMed, Google Scholar, and The Cochrane Library) was performed for relevant articles listed between January 2000 and December 2015. The review was confined to patients with primary and secondary bacterial or viral arterial infections, with or without fistulization and infection of bypass grafts and arteriovenous accesses. For the purposes of this summary, endografts can be considered to be an aortic aneurysm device or a covered stent. RESULTS: There are no societal guidelines. Endografts have been successfully applied to mycotic arterial aneurysms, aortoenteric, aortobronchial, and arterioureteric fistulae, and to anastomotic bleeds secondary to infection. Multiple reports indicate success at the control of hemorrhage in all locations. Short-term outcomes are good, but fatal infection-related complications, especially if antibiotic therapy is halted, are well reported and necessitate a more definitive plan for the long term. CONCLUSIONS: Stent grafts remain an important and viable option for the treatment of mycotic aneurysms, aortoesophageal and aortobronchial fistulae, and infected pseudoaneurysms in anatomically or technically inaccessible locations. In patients with a short life span (<6 months), no further intervention is generally required. In patients with a predicted life span >6 months, careful consideration should be given to a more definitive procedure. Life-long appropriate antibiotic therapy is strongly recommended for any patient receiving an endograft in an infected field.

Single-center retrospective review of ultrasound-accelerated versus traditional catheter-directed thrombolysis for acute lower extremity deep venous thrombosis.

Objective Systemic anticoagulation remains the standard for acute lower extremity (LE) deep venous thrombosis (DVT), but growing interest in catheter-directed thrombolysis (CDT) and its potential to reduce the incidence of post-thrombotic syndrome (PTS) has led to advent of ultrasound-accelerated CDT (US-CDT). Few studies to date have examined the outcomes of US-CDT against traditional CDT (T-CDT). Methods This is a retrospective, single-center review of all patients treated for acute LE DVT over a five-year period with either US- and T-CDT. Patients were stratified based on demographics, presentation, co-morbidities, risk factors, and peri-procedural data. Results Seventy-six limbs in 67 patients were treated; 51 limbs in 42 patients were treated with US-CDT, and 25 limbs in 25 patients were treated with T-CDT. Adjuncts include: pharmacomechanical thrombolysis ( n = 28 vs. 20, p = 0.04), angioplasty ( n = 22 vs. 18, p = 0.11), stenting ( n = 30 vs. 6, p ≤ 0.001), and IVC filter insertion ( n = 5 vs. 0, p = 0.07). Mean lysis times were 21 ± 1.7 and 24 ± 1.8 h for US- and T-CDT, respectively ( p = 0.26). Thirty (25 ultrasound, 5 traditional) limbs had complete lysis. Thirty-one (22 ultrasound, 9 traditional) limbs had incomplete lysis. Fifteen (4 ultrasound, 11 traditional) limbs had ineffective lysis ( p = 0.002 in favor of ultrasound). Four patients (3 US-CDT, 1 T-CDT) had recurrent ipsilateral thrombosis within 30 days ( p = 0.60). By Kaplan-Meier analysis, there were no significant difference between primary patency, primary-assisted patency, secondary patency, re-thrombosis, and recurrent symptoms at 6, 12, and 24 months. Conclusion US-CDT does not significantly improve mid-term patencies but results in greater acute clot burden reduction in patients with acute LE DVTs compared to T-CDT, which may be beneficial in reducing the long-term incidence of PTS.

Treatment options and outcomes for caval thrombectomy and resection for renal cell carcinoma.

OBJECTIVE: Advanced renal cell carcinoma (RCC) has a significant predisposition to vascular invasion. Tumor vascular invasion and thrombus are found in the renal vein and the inferior vena cava (IVC) in up to 10% to 25% of patients. This study reviewed the current status of radical nephrectomy with IVC thrombectomy for advanced RCC. METHODS: A two-level search strategy of the literature (MEDLINE, PubMed, The Cochrane Library, and Google Scholar) for relevant articles listed between January 2000 and December 2015 was performed. The review was confined to patients with primary RCC associated with vascular invasion. RESULTS: Untreated RCC with intravascular thrombus has a median survival of 5 months. Surgical exposure and intervention are tailored to the level of tumor thrombus. The 30-day mortality for radical nephrectomy with IVC thrombectomy is low (1.5%-10%), and the complication rates have been reported to be 18%, 20%, 26%, and 47% for IVC tumor thrombus level I, II, III, and IV disease, respectively. Disease-specific survival ranges from 40% to 60% at 5 years after nephrectomy and removal of the intravascular tumor. CONCLUSIONS: Radical nephrectomy with IVC thrombectomy is an effective cancer control operation that can be safely performed with acceptable mortality and morbidity. Preoperative imaging coupled with perioperative surgical management of the IVC is critical to procedural success and patient outcomes.

The Role of Endovascular In Situ Revascularization in the Treatment of Arterial and Graft Infections.

Mycotic aneurysms and prosthetic graft infections are traditionally treated with excision of the infected tissue or graft, often requiring anatomical or extraanatomical bypass, carrying significant morbidity and mortality. Currently, the role of endovascular repair without excision in this setting has yet to be defined. We present 2 case scenarios, whereby mycotic pseudoaneurysms were successfully treated with endovascular stent-graft coverage and to present an in-depth review of endovascular in situ revascularization in the treatment of arterial and graft infections. There are data to support the use of stent grafting in mycotic aortic and iliac aneurysms, lower and upper extremity native arterial infections, lower extremity prosthetic bypass infections, and infections of carotid artery aneurysms. It is our belief that this technique may be utilized as primary therapy if there is no significant contamination and certainly serves an essential role in acute rupture or hemorrhage. In situations where there is significant tissue infection, stent grafting should be considered as a bridge if traditional excision is warranted.

Outcomes of native superficial femoral artery chronic total occlusion recanalization after failed femoropopliteal bypass.

OBJECTIVE: When a bypass fails, the options are lysis, redo bypass, or endovascular intervention. If lysis of the original bypass is not considered an option, which is better-redo bypass or attempts at endovascular recanalization of the native system? This retrospective study examined the outcomes of native superficial femoral artery (SFA) chronic total occlusion (CTO) recanalization compared with redo bypass after failed femoropopliteal bypass. METHODS: Patients presenting with a symptomatic failed femoropopliteal bypass that underwent attempted CTO endovascular (EV) recanalization of the native SFA or a redo femoropopliteal bypass (BP) from 2000 to 2015 were analyzed. Patients undergoing catheter-directed thrombolysis were excluded. Time-dependent outcomes were assessed with life-table analyses. Factor analyses were performed using a Cox proportional hazard model for time-dependent variables. RESULTS: A total of 104 patients (69% male; average age, 65 years) underwent EV (n = 40) or BP (n = 64) after presentation with symptomatic occlusion of a previous femoropopliteal bypass graft (rest pain in 84% and life-style limiting claudication in 16%, 79% to the above-knee popliteal, 81% prosthetic). According to the TransAtlantic Inter-Society Consensus for the Management of Peripheral Arterial Disease classification, 91% of the lesions were category D and 19% were category C. Tibial runoff was one tibial vessel in 79% of the patients and two or more runoff vessels in the remainder. Lesions treated endovascularly underwent primary stenting with a median of 3 stents used. Of the bypasses performed, 69% were to the below knee popliteal and remainder were to the proximal tibials (68% of the patients had a venous conduit). At 30 days in EV vs BP, major adverse cardiovascular events were 3% and 8% (P = .24), major adverse limb events were 25% and 11% (P = .01), and the amputation rate was 8% and 8% (P = .96), respectively. Amputation-free survival was 33% ± 9% and 56% ± 8% (P = .02) and freedom from major adverse limb event was 19% ± 8% and 46% ± 7% (P = .04) at 3 years for EV vs BP, respectively. CONCLUSIONS: In a high-risk cohort when thrombolysis is excluded, BP is superior to EV after failure of a femoropopliteal bypass.

Equivalent outcomes with standard and heparin-bonded expanded polytetrafluoroethylene grafts used as conduits for hemodialysis access.

BACKGROUND: Obtaining and maintaining dialysis access after failure of autologous access sites remains a significant concern for patients on hemodialysis. Polytetrafluoroethylene (PTFE) is the most common conduit used. Heparin-bonded expanded PTFE (HB-PTFE) grafts have recently been introduced as an improved conduit, with suggestions that HB offers benefits because of its resistance to thrombosis. In this retrospective study, the outcomes of HB-PTFE were compared with standard wall PTFE (S-PTFE) arteriovenous grafts (AVGs). METHODS: From January 2004 to December 2014, 483 adults (46% male; mean age, 60 years; range, 25-87 years) with end-stage renal disease underwent placement of AVGs (234 HB-PTFE and 248 S-PTFE). The two groups did not differ significantly in demographics or access history. Patency, reintervention, infection, and functional dialysis rates were examined. RESULTS: Technical success was 99% in HB-PTFE and 98% in S-PTFE. The 30-day major adverse cardiovascular events were 2% in HB-PTFE and 3% in S-PTFE. Mean time to access was 5.1 ± 1.8 weeks for HB-PTFE and 6.9 ± 1.9 weeks for S-PTFE (P = .0001). Median follow-up was 23 months. The 2-year primary, assisted primary, and secondary patency rates were 20% ± 7% vs 18% ± 8% (P = .85), 35% ± 8% vs 28% ± 7% (P = .51), and 38% ± 6% vs 36% ± 7% (P = .83) for HB-PTFE vs S-PTFE, respectively. Both groups underwent a similar number of secondary interventions (2.1 and 1.9 interventions per person-year of follow-up for HB-PTFE vs S-PTFE respectively; P = .87). There were no significant differences in infection (11% vs 12%) or pseudoaneurysm formation (5% vs 6%) between HB-PTFE and S-PTFE groups. Functional dialysis durations were equivalent between HB-PTFE and S-PTFE groups. CONCLUSIONS: HB-PTFE grafts offer no distinct advantage over S-PTFE grafts for hemodialysis and should not be considered a preferential conduit for AVG.

Efficacy of prophylactic inferior vena caval filters in prevention of pulmonary embolism in the absence of deep venous thrombosis.

There is an increasing use of inferior vena caval filters (IVCFs) as prophylactic activity in the absence of a deep venous thrombosis (DVT) to prevent pulmonary embolism (PE) in high-risk patients. These devices are effective in preventing PE in the presence of lower extremity DVT, when anticoagulation is contraindicated or has failed. An electronic databases search of MEDLINE, PubMed, The Cochrane Library, and Google Scholar for relevant articles listed between January 2000 and December 2014 was performed. The review was confined to patients without a history of previous venous thromboembolism and no evidence of changes on venous duplex imaging suggestive of previous DVT. At present, the use of prophylactic IVCF is predominantly in the trauma, orthopedic, and bariatric surgical populations. Currently, no class I studies exist to support insertion of an IVCF in a patient without an established DVT or PE. However, there is a body of class II and class III evidence that would support the use of IVCFs in certain "high-risk" patients who do not have a documented DVT or the occurrence of a PE. Widespread use of prophylactic IVCFs is not supported by evidence and should be discouraged.

Current Status of Clot Removal for Acute Pulmonary Embolism.

Acute pulmonary embolism (PE) continues to carry a high mortality if not recognized early and treated aggressively. Rapid recognition and diagnosis remains the mainstay of all efforts. Risk stratification early is paramount to guide therapy and achieve successful outcomes. Pulmonary emboli can generally be classified as massive, submassive, or stable. Fibrinolysis and/or surgical embolectomy are recommended for the treatment of the patient with massive PE to rescue the patient and restore hemodynamic stability. Current trials support an aggressive approach. In submassive PE, determination of right ventricular (RV) strain by echocardiography and biomarker assessment (troponin and B-type natriuretic peptide) identify patients who can benefit from catheter-directed therapy with the therapeutic intent of achieving a rapid reduction of RV afterload, prevention of impending hemodynamic collapse and prolonged in-hospital and outpatient survival. Current trials have not shown long-term benefit for this approach to date, and thus, this therapy should only be offered to select patients. Stable PE can be treated using both an inpatient and an outpatient approach, based on the available infrastructure. Therapy for PE continues to evolve and stratification of risks and benefits remain the key to implementation of invasive strategies.

Objective performance goals after endovascular intervention for critical limb ischemia.

OBJECTIVE: During the last decade, primary endoluminal therapy for critical limb ischemia (CLI), assessed as rest pain and tissue loss of the lower extremity, has significantly increased. Reporting of patient-centered outcomes using the new Society for Vascular Surgery objective performance goals (OPGs) has been limited. This study examined the OPGs for infrainguinal endovascular management of CLI. METHODS: A prospective database of patients undergoing endovascular treatment of the lower extremity for CLI between 2000 and 2011 was queried. Evaluated were clinical efficacy (absence of recurrent symptoms, maintenance of ambulation and absence of major amputation), amputation-free survival (survival without major amputation), and freedom from major adverse limb events (MALEs; above-ankle amputation of the index limb or major reintervention - new bypass graft, jump/interposition graft revision). RESULTS: A total of 728 patients (60% male; age, 68 ± 14 years) underwent lower extremity interventions for CLI (66% tissue loss); of these, 39% had superficial femoral artery and tibial interventions. Diabetes mellitus was present in 71%, hyperlipidemia in 64%, and chronic renal insufficiency in 37%. Technical success was 96%. The overall rate at 30 days of major adverse cardiovascular events (MACEs) was 3% and MALEs was 12%. At 5 years, clinical efficacy was (mean ± standard error of the mean) 42% ± 5%, amputation-free survival was 41% ± 7%, and freedom from MALEs was 51% ± 4%. Clinical efficacy was significantly different in those presenting with rest pain and tissue loss and in the anatomic high-risk group compared with the clinical high-risk group, and both were worse compared with the group without clinical or high-risk criteria. CONCLUSIONS: Endoluminal therapy for CLI is associated with early low MACE rates but high MALE rates. When the key outcome of amputation free survival is considered, predictors of a better outcome were absence of current smoking, a lower modified Edifoligide for the Prevention of Infrainguinal Vein Graft Failure (PREVENT III) amputation risk score, better preoperative ambulation status, lower MACEs, and discharge disposition to home. The presence of tissue loss and anatomic risk factors negatively affect outcomes. Longer-term outcomes after endovascular intervention for CLI remain relatively poor, with <40% success in objective performance outcomes at 5 years.

Outcomes of Isolated Tibial Endovascular Interventions for Tissue Loss in CLI Patients on Hemodialysis.

PURPOSE: To compare the objective performance goals (OPGs) and patient-centered outcomes of isolated tibial interventions in patients with tissue loss who were on hemodialysis (HD) to patients with tissue loss who were not on HD. METHODS: Interrogation of a prospectively maintained database identified 242 critical limb ischemia (CLI) patients who underwent isolated tibial interventions for tissue loss in a single limb between 2007 and 2012. The 78 patients (mean age 66±12 years; 44 men) on HD were compared with 164 patients (mean age 50±13 years; 82 men) who were not on HD. There was an equal distribution of the tibial vessels treated; 152 (63%) patients had more than one treated tibial vessel. Patient-centered outcomes of clinical efficacy (absence of recurrent symptoms, maintenance of ambulation, and no major amputation), amputation-free survival (AFS), and freedom from major adverse limb events (MALE) were evaluated. The Society for Vascular Surgery OPGs were defined at 30 days and 1 year. RESULTS: The 30-day major adverse cardiac events was significantly higher (p=0.004) in the HD group (5, 5%) compared with the no-HD group (0%), but both remained under the stated OPG of ≤10%. The 30-day MALE rates were significantly higher than the stated ≤9% OPG at 13% and 18% for the no-HD and HD groups, respectively. At 1 year, the rates for AFS, freedom from MALE, limb salvage, and survival did not achieve the stated Society for Vascular Surgery OPGs in the HD group. Clinical efficacy was 61% and 25% at 3 years for the no-HD and HD groups, respectively (p<0.01). Overall, AFS was 54% and 22% and freedom from MALE was 56% and 27% at 3 years for the no-HD and HD groups, respectively (both p<0.01). CONCLUSION: Tibial intervention for tissue loss in patients on HD is a valid treatment option but is associated with a high MALE rate. Three-year outcomes remain relatively poor, with <25% success in terms of clinical efficacy and AFS.

Early Experience With a Novel Hybrid Vascular Graft for Hemodialysis Access Creation in Patients With Disadvantaged Anatomy.

PURPOSE: To describe the use of the Hybrid vascular graft in disadvantaged anatomy for hemodialysis access creation and compare outcomes to standard-wall polytetrafluoroethylene (PTFE) grafts. METHODS: In a retrospective analysis, 25 patients (mean age 65±14 years; 13 men) who received the Hybrid graft were compared with 35 contemporaneous patients (mean age 63±12 years; 20 men) who received a standard PTFE graft for hemodialysis access over a 2-year period. Criteria for Hybrid graft placement were (1) exhausted or inadequate peripheral veins for arteriovenous fistula (AVF) creation and concomitant small target veins that precluded conventional PTFE graft placement, (2) previous graft anastomosis or a stent in the venous target at the level of the axilla, or (3) failed brachial-basilic or brachial-brachial upper arm transposition AVF with a small target vein at the axilla. Efficacy, anatomic and clinical considerations, and technique were reviewed; patency rates, complications, and reinterventions were examined. RESULTS: Technical success was achieved in all cases, and all grafts were usable for hemodialysis. Seven of 25 Hybrid patients required stent-graft extensions and 3 patients required angioplasty to improve venous outflow at the time of Hybrid graft insertion. Three of 35 standard PTFE graft patients required angioplasty to improve venous outflow at the time of graft insertion. There was no perioperative mortality or procedure-related morbidity in either group. Median follow-up was 21 months. The patient survival estimate was 66% at 2 years. Estimated primary patency (24% vs 18%, p>0.05), assisted primary patency (34% vs 28%; p>0.05), and secondary patency rates (40% vs 38%, p≥0.05) at 24 months were equivalent for Hybrid vs PTFE grafts, respectively. Venous hypertension was not a complication following Hybrid graft implantation but was seen in 2 patients with the standard PTFE graft. CONCLUSION: The Hybrid graft offers a safe, technically effective alternative for patients with disadvantaged anatomy requiring hemodialysis access and has comparable outcomes to standard PTFE grafts. Further clinical experience and long-term data are required for determining the proper utility of this device in chronic dialysis-dependent patients.

Outcomes of femoropopliteal interventions for critical ischemia in the hemodialysis-dependent patient.

BACKGROUND: The number of patients maintained on hemodialysis is rising. There are limited data on the outcomes of femoropopliteal interventions, both open and endovascular, in this population. This report examines the anatomic and clinical outcomes in this population. METHODS: A database of patients undergoing open (OPEN) and endoluminal (ENDO) intervention for femoropopliteal disease (2000 to 2010) was retrospectively queried. Patients on hemodialysis with critical ischemia at the time of surgery or intervention were selected. Patients who underwent tibial bypass or had concomitant tibial interventions were excluded. Kaplan-Meier analyses were performed to assess time-dependent outcomes. Factor analyses were performed for time-dependent variables. RESULTS: One hundred sixty-one hemodialysis-dependent patients underwent either OPEN or ENDO procedures for critical ischemia. Of these, 70 patients were treated with OPEN procedures and 91 with ENDO procedures. ENDO patients were more likely to present with a higher cardiac risk index (P = 0.0001), metabolic syndrome (P = 0.02), cerebrovascular disease (P = 0.01), and a dependent living status preoperatively (P = 0.04). ENDO patients presented with more rest pain and tissue loss (P = 0.03). OPEN patients presented with more advanced lesions (P = 0.04). Combined morbidity was higher in the OPEN group (P = 0.05). Cumulative patency (P = 0.04) and clinical efficacy (P = 0.05) were higher in the OPEN group compared to those in the ENDO group. CONCLUSIONS: Hemodialysis patients undergoing femoral-popliteal endovascular interventions for symptomatic disease have a low cumulative patency and clinical efficacy. Although open surgical revascularization has higher perioperative morbidity and a trend toward higher perioperative mortality, it provides a superior 5-year cumulative patency and clinical efficacy and should be considered in this population subgroup.

Retrograde transpopliteal access is safe and effective-it should be added to the vascular surgeon's portfolio.

BACKGROUND: The aim of the study was to review the outcomes of superficial femoral artery (SFA) interventions using a retrograde transpopliteal access approach after failed antegrade recanalization. METHODS: A database of patients undergoing endovascular treatment of the SFA between 2008 and 2011 was retrospectively queried, and those cases with transpopliteal artery retrograde access were analyzed. Time-dependent outcomes were determined by Kaplan-Meier survival analyses. RESULTS: A total of 16 patients (75% men; mean age 61 ± 9 years) underwent retrograde popliteal access after failed antegrade attempts. Patients had multiple cardiovascular comorbidities with a mean modified cardiac index score of 3.1 ± 1.8. The reason for intervention was lifestyle-limiting claudication in 67% of cases and critical ischemia in the remainder. Most of the lesions were Trans-Atlantic Inter-Society Consensus II C and D. Retrograde ultrasound-guided puncture of the popliteal artery was successful in all cases and there were no local site complications. Intervention was successful in 94% of cases. One uncomplicated perforation (7%) was encountered during attempted recanalization of the SFA in the thigh. There was no perioperative morbidity or 30-day mortality. The 30-day major adverse cardiovascular events rate was 6% but both 30-day major adverse limb events and the 30-day major amputation rate were 0%. There was a 40% increase in actual ankle-brachial index (ABI); 93% of patients achieved an ABI rise >0.15. On longer term follow-up, 2 patients developed restenosis and 1 an asymptomatic occlusion. Both restenosis patients required re-angioplasty. Two patients required expected toe amputations as a result of their presenting symptoms. The primary patency was 66 ± 9%, assisted patency 81 ± 9%, and secondary patency 87 ± 8% at 2 years. Limb salvage was 100%. Clinical efficacy was 63 ± 9% at 2 years. CONCLUSIONS: Ultrasound-guided retrograde transpopliteal access is a safe and successful technique, which extends the ability to perform endovascular interventions after failed antegrade approaches.

Open arterial revascularization of the critically ischemic foot using arterial homograft.

BACKGROUND: Revascularization alternatives for patients with critical limb ischemia and without adequate autogenous vein remain challenging. We reviewed our experience with the use of arterial homograft as a conduit for limb salvage in patients with limb ischemia and active lower extremity infections. METHODS: A retrospective review of patients who underwent open arterial revascularization of the lower extremity with cryopreserved femoral artery homograft for the treatment of symptomatic critical limb ischemia (i.e., foot ulceration, infection, or gangrene) during an 18-month period was performed. Relevant clinical variables and treatment outcomes were analyzed. Clinical success was defined as limb salvage for one year, patency of the reconstruction, and wound healing. RESULTS: Thirteen patients (5 men; average age 71 +/- 83 years, range 51-87 years) were treated during this study period. Treatment indications included 10 (77%) foot ulcerations, 2 (15%) critically ischemic limbs without ulceration, and 1 (8%) infected polytetrafluoroethylene bypass graft with acute occlusion and limb ischemia. A femoral below-the-knee popliteal bypass was performed in 4 (1%), femoral to anterior tibial artery in 4 (31%), femoral to posterior tibial artery in 3 (23%), and femoral to peroneal artery in 2 (15%). All 13 limbs were preserved. Minor amputations were performed in 6 patients, 2 underwent toe amputations and 4 patients had a trans-metatarsal amputation. The cumulative patency rate at 6, 9, and 18 months was 92.3%, 70.3%, and 58.6%, respectively. CONCLUSION: Open arterial revascularization with arterial femoral homograft is an acceptable treatment method in patients with critical limb ischemia and active infection in whom autogenous vein is not available or the use of a synthetic conduit is not possible.

Elevated heparin-induced antibodies are more common in diabetic patients with vascular disease.

Background. Hypercoagulable disorders can lead to deep vein thrombosis (DVT), arterial thrombosis or embolization, and early or recurrent bypass graft failure. The purpose of this study was to identify whether diabetes increased the likelihood of heparin-induced platelet factor 4 antibodies in at risk vascular patients. Methods. We reviewed clinical data on 300 consecutive patients. A hypercoagulable workup was performed if patients presented with (1) early bypass/graft thrombosis (<30 days), (2) multiple bypass/graft thrombosis, and (3) a history of DVT, pulmonary embolus (PE), or native vessel thrombosis. Relevant clinical variables were analyzed and compared between patients with diabetes (DM) and without diabetes (nDM). Results. 85 patients (47 women; age 53 ± 16 years, range 16-82 years) had one of the defined conditions and underwent a hypercoagulable evaluation. Screening was done in 4.7% of patients with early bypass graft thrombosis, 60% of patients were screened because of multiple bypass or graft thrombosis, and 35.3% had a previous history of DVT, PE, or native vessel thrombosis. Of the 43 patients with DM and 42 nDM evaluated, 59 patients (69%) had an abnormal hypercoagulable profile. An elevated heparin antibody level was present in 30% of DM and 12% of nDM patients (chi-squared test P < 0.04). Additionally, DM was associated with a higher likelihood of arterial complications while nDM was associated with a higher rate of venous adverse events (chi-squared test P < 0.003). Conclusions. Diabetes is associated with a higher likelihood of developing heparin-induced antibodies and an increased combined incidence of arterial complications that include early or multiple bypass/graft thrombosis. This finding may influence the choice of anticoagulation in diabetic patients at risk with vascular disease.

Current efficacy of open and endovascular interventions for advanced superficial femoral artery occlusive disease.

BACKGROUND: There has been a marked paradigm shift in the treatment of symptomatic femoro-popliteal disease with a shift from open to endoluminal therapy. The consequence of this shift in therapy is poorly described. The aim of this study is to examine the clinical efficacy of this shift in treatment strategies. METHODS: A database of patients undergoing open (OPEN) and endoluminal (ENDO) intervention for TASC II C and D femoro-popliteal lesions between 1990 and 2010 was retrospectively queried. Kaplan-Meier survival analyses were performed to assess time-dependent outcomes. Factor analyses were performed using a multivariant Cox proportional hazard model for time-dependent variables. RESULTS: A total of 2593 limbs underwent either OPEN or ENDO treatment for symptomatic and anatomically advanced femoro-popliteal disease over a 20-year period. There was a two-fold rise in endovascular interventions between the first and second decade. In the first decade, 80% of the interventions were OPEN, while in the second decade, 61% of the interventions were ENDO. There were equivalent comorbidities in both groups, and survival was also equivalent. Endoluminal therapy was more commonly performed on claudicants. Thirty-day mortality was equivalent, but major morbidity was higher in OPEN compared with ENDO. Cumulative patency was equivalent in both groups with a similar reintervention rate. In contrast, clinical efficacy (freedom from recurrent symptoms, maintenance of ambulation, and avoidance of major amputation) was significantly higher in the OPEN group (P = .002). The presence of critical limb ischemia, diabetes, end-stage renal disease, and poor tibial runoff were predictors of poor anatomic and functional outcomes in both groups. CONCLUSIONS: There has been a marked shift in treatment modality for advanced femoro-popliteal disease with a lowering of the symptomatic threshold for intervention over 2 decades, likely spurred by the ease of endoluminal interventions. Although peri-procedural and anatomic outcomes for both procedures are equivalent, it appears that open surgery carries a superior long-term clinical efficacy. This superiority is negatively influenced by poor preoperative ambulation status, high modified Cardiac Risk Score, worse presenting symptoms, the occurrence of major adverse cardiovascular events, poor tibial runoff, the absence of hemodynamic success, and occlusion of the original bypass.

Volume Flow Measurements in Arteriovenous Dialysis Access in Patients with and without Steal Syndrome.

Introduction. Dialysis associated steal syndrome (DASS) constitutes a serious risk for patients undergoing vascular access operations. We aim to assess the measured volume flow using ultrasound in patients with clinically suspected steal syndrome and determine differences in flow among types of arteriovenous (AV) access. Methods. Patients with permanent hemodialysis access with and without ischemic steal underwent duplex ultrasound (US) exams for the assessment of volume flow and quantitative evidence of hemodynamic steal. Volume flow was measured in the proximal feeding artery. Results. 118 patients underwent US of which 82 (69.5%) had clinical evidence of steal. Women were more likely to develop steal compared to men (chi-squared test P < 0.04). Mean volume flow in patients with steal was 1542 mL/min compared to 1087 mL/min (P < 0.002) in patients without evidence of steal. A significant difference in flow volumes in patients with and without steal was only seen in patients with a brachial-cephalic upper arm AV fistula (AVF) (P < 0.002). When comparing different types of access with steal, brachial-cephalic upper arm AVFs had higher volume flows than the upper extremity AV graft (AVG) group (P = 0.04). Conclusion. In patients with DASS, women were more likely to develop steal syndrome. Significantly higher volume flows were seen with brachial-cephalic upper arm AVF in patients with steal compared to those without. A physiologic basis of this US finding may be present, which warrants further study into the dynamics of flow and its relationship to the underlying peripheral arterial pathology in the development of ischemic steal.

Retrograde pedal/tibial artery access for treatment of infragenicular arterial occlusive disease.

Endovascular intervention has emerged as an accepted modality for treating patients with critical limb ischemia. However, this therapy poses multiple challenges to the interventionalist due to the presence of widespread multilevel disease, long and complex occlusive lesions, and the common involvement of the tibial vessels. Retrograde pedal/tibial access is a relatively new technique that allows the treatment of tibial occlusive lesions when conventional endovascular techniques fail. This article reviews the technical details and published data regarding this technique and evaluates its use in this difficult-to-treat patient population.