Anticoagulation Management Post Pulmonary Embolism.

Pulmonary embolus (PE) carries a significant impending morbidity and mortality, especially in intermediate and high-risk patients, and the choice of initial anticoagulation that allows for therapeutic adjustment or manipulation is important. The preferred choice of anticoagulation management includes direct oral anticoagulants. Vitamin K antagonists and low-molecular-weight heparin are preferred in special populations or selected patients such as breastfeeding mothers, those with end-stage renal disease, or obese patients, among others. This article reviews the primary and longer-term considerations for anticoagulation management in patients with PE and highlights special patient populations and risk factor considerations.

Stent Grafts Can Convert Unusable Upper Arm Arteriovenous Fistulas into a Functioning Hemodialysis Access: A Retrospective Case Series.

INTRODUCTION: Not all newly created arteriovenous fistulas (AVFs) successfully mature and develop into a functioning access for hemodialysis. Percutaneous transluminal angioplasty (PTA) and balloon-assisted maturation (BAM) have been utilized to either treat flow-limiting stenoses or to promote and accelerate maturation. We hypothesized that unusable upper arm AVFs can be rescued by conversion to a functional access using the percutaneous placement of a stent graft (SG). METHODS: Clinical data on 12 patients with an early non-usable upper arm AVF underwent percutaneous revision using SGs. There were six brachial-cephalic, three brachial-basilic, and three brachial-brachial vein transposition AVFs. RESULTS: All patients had either at least two or more stenoses (>2 cm) within the fistula conduit, or a long segment stenosis (>4 cm) in combination with shorter segment stenoses. Nine patients had failed PTA. Three patients had failed BAM at outside access centers. All patients were referred for failure to achieve access cannulation and concomitant hemodialysis through the AVF. SGs were placed retrograde toward the arterial anastomoses and ranged in diameter (6, 7, and 8 mm in four, seven, and one patients, respectively). The average length of the SG was 10 cm (range 5-15 cm). All SGs were post-balloon dilated at the time of placement. All AVFs were salvaged, and patients were able to maintain functional use of their access with cannulation occurring through the SG. The primary patency rate at 6 and 12 months was 91% [95% confidence interval (CI), 56-98%] and 65% (95% CI, 32-87%), respectively (n = 11 and 5 at risk, respectively). The secondary patency rate at 6 and 12 months was 100 and 72% (95% CI, 46-93%), respectively (n = 11 and 7 at risk, respectively). CONCLUSION: This report outlines a successful initial experience using SGs to rescue, preserve, and convert an unusable upper arm AVF into a functioning hemodialysis access.

Case Report: En Bloc Resection of Pancoast Tumor with Adjuvant Aortic Endograft and Chemoradiation.

"Pancoast" tumors frequently require a multidisciplinary approach to therapy and are still associated with high morbidity and mortality. Due to their sensitive anatomic location, complex resections and chemoradiation regimens are typically required for treatment. Those with signs of aortic invasion pose an even greater challenge, given the added risks of cardiopulmonary bypass for aortic resection and interposition. Placement of an aortic endograft can facilitate resection if the tumor is in close proximity to or is invading the aorta. Prophylactic endografting to prevent radiation-associated aortic rupture has also been described. This case describes a 60-year-old female who presented with a stage IIIa left upper lobe undifferentiated non-small-cell carcinoma encasing the subclavian artery with thoracic aorta and bony invasion. Following carotid-subclavian bypass with Dacron, en bloc resection of the affected lung, ribs, and vertebral bodies was performed. The aorta was prophylactically reinforced with a Gore TAG thoracic endograft prior to adjuvant chemoradiation. The patient remains disease-free at more than 5 years follow-up after completing her treatment course. Endovascular stenting with subsequent chemoradiation may prove to be a viable alternative to palliation or open operative management and prevention of aortic injury during tumor resection and/or adjuvant therapy in select patients with aortic involvement.

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.

Open repair and venous inflow plication of the arteriovenous fistula is effective in treating vascular steal syndrome.

BACKGROUND: Vascular steal syndrome related to a dialysis arteriovenous fistula (AVF) can lead to symptoms of distal ischemia, limb loss, digit ulceration, and gangrene. Several complex procedures have been used to augment and restore distal limb perfusion while maintaining a functional AVF. We reviewed our experience in treating AVF-related vascular steal syndrome by simple plication of the initial AVF inflow segment. METHODS: Clinical data of 26 patients (15 men; mean age, 58 years; range, 26-80) with vascular steal syndrome related to their AVF underwent plication during a 36-month period. There were 18 brachial-cephalic AVFs and 8 brachial-basilic AVFs with vein transposition. Relevant clinical variables, imaging studies, and treatment variables were analyzed. RESULTS: Eighty-four percent of patients had hypertension, 62% were diabetics, and 15% had a previous limb or digit amputated. Hand pain, skin ulceration, or gangrene was present in 96%, 15%, and 12% of patients, respectively; 19% of patients had more than one symptom. Twelve (46%) patients had an aortic arch and upper extremity arteriogram, of which 67% showed evidence of arterial disease. One patient required percutaneous balloon-expandable stent treatment of a proximal left subclavian artery stenosis to improve flow. Duplex-derived volume flow measurements of the AVF were obtained with an average flow of 1.95 ± 0.83 L/min. Open repair and venous inflow plication was performed in all 26 patients. Average flow reduction in patients with preoperative and postoperative flow measurements was 0.6 ± 0.5 L/min (P < 0.05). There was a 12% revision rate within 3 months. Symptom resolution was achieved in 92% of patients while maintaining a functioning access out to 1 year. Two remaining patients who did not improve and proceeded to ligation of the AVF. CONCLUSIONS: Surgical plication of the initial AVF inflow segment offers a simple solution to preserve the dialysis access and resolve symptoms related to vascular steal associated with high volume flow through the AVF.

Evaluating and treating venous outflow stenoses is necessary for the successful open surgical treatment of arteriovenous fistula aneurysms.

BACKGROUND: Arteriovenous fistula (AVF) aneurysms (AVFAs) can lead to skin erosion, bleeding, difficult access while on hemodialysis, and poor cosmetic appearance. We reviewed our experience in treating patients with aneurysmal dilatation of their AVF. METHODS: We reviewed clinical data of 48 patients (37 men; overall mean age, 55 years; range, 28-85 years) with an AVFA who underwent treatment during a 30-month period. Relevant clinical variables and treatment outcomes were analyzed. RESULTS: All patients underwent a fistulogram, and 90% required percutaneous angioplasty to improve outflow. Fifty-six percent of patients had one stenotic outflow lesion, and 44% had at least two tandem outflow stenoses that required treatment. Open repair with aneurysmorrhaphy was performed in one stage in 64% of patients and in two stages in 36%. A tunneled hemodialysis catheter was required in 11 patients (23%) until the surgically repaired AVF was ready for use again, comprising 10 patients treated with single-stage surgery and only one patient in the staged group. All AVFAs were effectively treated, and patients were able to maintain functional use of their access when healed. CONCLUSIONS: There is a high association of venous outflow stenoses and AVFA. Comprehensive therapy should encompass treatment of any venous outflow stenoses before open AVFA repair. A two-stage repair may decrease tunneled hemodialysis catheter use in patients with multiple aneurysms.

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.

Vitamin k dependent proteins and the role of vitamin k2 in the modulation of vascular calcification: a review.

Vascular calcification, a cause of cardiovascular morbidity and mortality, is an actively regulated process involving vitamin K dependent proteins (VKDPs) among others. Vitamin K is an essential micronutrient, present in plants and animal fermented products that plays an important role as a cofactor for the post-translational γ-carboxylation of glutamic acid residues in a number of proteins. These VKDPs require carboxylation to become biologically active, and they have been identified as having an active role in vascular cell migration, angiogenesis and vascular calcification. This paper will review the process of vascular calcification and delineate the role that vitamin K2 plays in the modulation of that process, through the activation of VKDPs. One such VKDP is Matrix Gla Protein (MGP), which when activated inhibits osteogenic factors, thereby inhibiting vascular and soft tissue calcification.

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.

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.

Spinal cord stimulation for chronic limb ischemia.

The treatment of chronic limb ischemia involves the restoration of pulsatile blood flow to the distal extremity. Some patients cannot be treated with endovascular means or with open surgery; some may have medical comorbidities that render them unfit for surgery, while others may have persistent ischemia or pain even in the face of previous attempts at reperfusion. In spinal cord stimulation (SCS), a device with electrodes is implanted in the epidural space to stimulate sensory fibers. This activates cell-signaling molecules that in turn cause the release of vasodilatory molecules, a decrease in vascular resistance, and relaxation of smooth muscle cells. SCS also suppresses sympathetic vasoconstriction and pain transmission. When patient selection is based on microcirculatory parameters, SCS therapy can significantly improve pain relief, halt the progression of ulcers, and potentially achieve limb salvage.

Endovascular techniques in limb salvage: infrapopliteal angioplasty.

Critical limb ischemia (CLI) results from inadequate blood flow to supply and sustain the metabolic needs of resting muscle and tissue. Infragenicular atherosclerosis is the most common cause of CLI, and it is more likely to develop when multilevel or diffuse arterial disease coincides with compromised run-off to the foot. Reports of good technical and clinical outcomes have advanced the endovascular treatment options, which have gained a growing acceptance as the primary therapeutic strategy for CLI, especially in patients with significant risk factors for open surgical bypass. In fact, endovascular recanalization of below-the-knee arteries has proven to be feasible and safe, reduce the need for amputation, and improve wound healing. The distribution of various vascular territories or angiosomes in the foot has been recognized, and it appears advantageous to revascularize the artery supplying the territory directly associated with tissue loss. In addition, the targeted application and local delivery of drugs using drug-coated balloons (DCB) during angioplasty has the potential to improve patency rates compared to balloon angioplasty alone.

A longitudinal view of improved management strategies and outcomes after iatrogenic iliac artery rupture during endovascular aneurysm repair.

BACKGROUND: Intraoperative rupture of the iliac artery is a serious complication of endovascular aneurysm repair (EVAR), the outcomes of which have changed with increasing experience and improved endovascular tools over the past 2 decades. Over the past 15 years, the incidence and management of iliac rupture has changed as devices have improved and experience has grown. This study reviews our longitudinal experience with this complication. METHODS: All cases of iliac artery rupture during EVAR from 1997 through 2011 were reviewed for presentation, treatment strategies, and outcomes. RESULTS: Iliac artery rupture complicated 20 (3%) of 707 EVARs performed. Sixteen (80%) common and four (20%) external iliac arteries were ruptured. Hypotension (systolic blood pressure: <90 mm Hg) was present in 11 (55%) cases. Five open bypasses were performed (25%), whereas 15 were repaired using an endovascular approach (75%). All open repairs (100%) were associated with postoperative morbidity (one wound infection, four multiorgan system failure), whereas three of the 15 patients (23%) repaired endovascularly experienced postoperative morbidity (cerebrovascular accident, myocardial infarction, line infection). There were no intraoperative deaths. There were four (20%) early deaths in the intensive care unit (<3 days postoperatively), all of which were associated with resection of bilateral hypogastric arteries and were due to complications of pelvic ischemia and/or multiorgan system failure. CONCLUSIONS: Iliac artery rupture remains relatively uncommon but can carry a high morbidity and mortality. As device technology, imaging quality for preoperative planning, and experience level have improved, iliac rupture has become less common, and outcomes in the setting of iliac rupture have significantly improved. Endoluminal management has evolved as the primary treatment strategy. Resection of both hypogastric arteries is associated with mortality from pelvic ischemia, a likely indicator of systemic disease.

Clinical efficacy of concomitant tibial interventions associated with superficial femoral artery interventions in critical limb ischemia.

BACKGROUND: Combined superficial femoral artery (SFA) and tibial angioplasty (TA) are a common treatment for critical limb ischemia. Poor tibial runoff significantly compromises durability and clinical effectiveness of SFA interventions. The aim of this study is to determine clinical and anatomic outcomes of SFA interventions in patients with equally compromised runoff, with and without concomitant TA. METHODS: The database of patients undergoing endovascular treatment of SFA (1999-2009) was retrospectively queried. Patients with poor runoff, scored>10 by modified Society for Vascular Surgery criteria, were selected. Preoperative angiograms were reviewed to assess distal popliteal and tibial runoff. Kaplan-Meier analyses were performed to assess time-dependent outcomes. Factor analyses were performed for time-dependent variables. RESULTS: A total of 162 limbs with a runoff score>10 (56% men; average age, 69 years) underwent endovascular intervention for symptomatic SFA disease: 61 (54% men) underwent TA but the remaining 101 (57% men) did not. The groups were matched for age, sex, and SFA anatomy (Trans-Atlantic Inter-Society Consensus II C/D lesions: 56% no TA vs 62% TA; P=.5). Presenting symptoms were similar between no TA and TA groups (rest pain: 40% vs 32%; tissue loss: 60% vs 68%; P=.3). Three-year survival favored the TA group (79%±5%) vs no TA (68%±5%; P=.06). Three-year anatomic outcomes in no TA vs TA group, including primary patency (45%±6% vs 63%±8%; P=.04), assisted primary patency (55%±6% vs 75%±7%; P=.03), and secondary patency (57%±6% vs 77%±7%; P=.03) were all superior in the TA group. Target vessel revascularization in no TA vs TA (61%±6% vs 74%±8%; P=.002) and target extremity revascularization (42%±6% vs 59%±8%; P=.06) also favored the TA group. However the comparison of no TA vs TA for clinical success (39%±6% vs 47%±8%; P=.6), freedom from recurrent symptoms (59%±6% vs 60%±9%; P=.1), amputation-free survival (46%±5% vs 63%±7%; P=.06), and limb salvage at 3 years (63%±6% vs 74%±7%; P=.6) were similar. CONCLUSIONS: TA in patients with poor runoff has a positive effect on SFA anatomic outcomes. However, clinical success was not affected. Concomitant TA appears not to add clinical benefit to SFA intervention in critical limb ischemia.

Comparison of outcomes of one-stage basilic vein transpositions and two-stage basilic vein transpositions.

BACKGROUND: Basilic vein transpositions (BVTs) provide autologous hemodialysis access in the upper extremity. We report and compare our experience using the two techniques that are commonly performed to create BVTs: the one-stage and the two-stage technique. METHODS: A retrospective review was performed on patients who underwent BVT from June 2006 to June 2010 from a database of all patients undergoing dialysis access procedures. One hundred six patients, mean age of 54 years (41% male), who received upper-arm basilic vein-only transposition were identified and were stratified based on one-stage and two-stage BVTs. Anatomic outcomes and functionality were determined and compared between stages. RESULTS: Seventy-seven patients underwent two-stage BVT, and 29 underwent one-stage BVT. Fifty-one percent and 79% of the two-stage group and the one-stage group, respectively, had had a previous failed ipsilateral permanent access. Catheter dialysis at time of surgery was 14% in one-stage BVT and 43% in two-stage BVT. Immediate technical success was obtained in all cases. The rate of primary failure was 21% in the one-stage group and 18% in the two-stage group. Reintervention rates for the one-stage group and the two-stage group were 62% and 66%, respectively. Primary patency for the one-stage group and the two-stage group at 1 year was 82% and 67%, at 2 years was 81% and 27%, and at 3 years was 51% and 18%, respectively. Secondary patency for the one-stage group and the two-stage group at 1 year was 91% and 81%, at 2 years was 80% and 61%, and at 3 years was 58% and 45%, respectively. Thirty-day mortality was 0% in both groups, and all-cause morbidity was 12% in both groups (counting all stages). CONCLUSION: One-stage BVTs have a similar number of initial failures and secondary interventions as two-stage BVTs. One-stage BVTs achieved better primary and cumulative patencies. There appears to be no advantage to a two-stage BVT in equally matched patients.

Impact of metabolic syndrome on the outcomes of superficial femoral artery interventions.

BACKGROUND: Metabolic syndrome (MetSyn) is an epidemic in the United States and is associated with early onset of atherosclerosis, increased thrombotic events, and increased complications after cardiovascular intervention. MetSyn is found in ∼50% of patients with peripheral vascular disease. However, its impact on peripheral interventions is unknown. The aim of this study is to determine the outcomes of superficial femoral artery (SFA) interventions in patients with and without MetSyn. METHODS: A database of patients undergoing endovascular treatment of SFA disease between 1999 and 2009 was retrospectively queried. MetSyn was defined as the presence of ≥3 of the following criteria: blood pressure ≥130 mm Hg/≥85 mm Hg; triglycerides ≥150 mg/dL; high-density lipoprotein ≤50 mg/dL for women and ≤40 mg/dL for men; fasting blood glucose ≥110 mg/dL; or body mass index ≥30 kg/m(2). Kaplan-Meier survival analyses were performed to assess time-dependent outcomes. Factor analyses were performed using a Cox proportional hazard model for time-dependent variables. RESULTS: A total of 1018 limbs in 738 patients (64% male, average age 67 years) underwent endovascular treatment for symptomatic SFA disease with 45% of patients meeting the criteria for MetSyn. MetSyn patients were more likely to be female (P = .001), to present with critical ischemia (rest pain/tissue loss: 55% MetSyn vs 45% non-MetSyn; P = .001), have poorer ambulatory status (P = .001), and have more advanced SFA lesions (TransAtlantic Inter-Society Consensus II C/D: 51% vs 11%; P = .001) and worse tibial runoff (P = .001). MetSyn patients required more complex interventions (P = .0001). There was no difference in mortality and major adverse cardiac events, but systemic complications (4% vs 1%; P = .001) and major adverse limb events (12% vs 7%; P = .0009) were significantly higher in the MetSyn group. Immediate postprocedural hemodynamic improvement, resolved or improved symptoms, and restoration of impaired ambulation were equivalent in both groups. Early failure (<6 months) was more common in those with MetSyn. At 5 years, primary, assisted primary, and secondary patencies were not affected by the presence of MetSyn. The presence of MetSyn was associated with a decrease in clinical efficacy, decreased freedom from recurrent symptoms, and decreased freedom from major amputation at 5 years. CONCLUSIONS: MetSyn is present in nearly half of the patients presenting with SFA disease. These patients present with more advanced disease and have poorer symptomatic and functional outcomes compared with those patients without MetSyn.

Bypass surgery in limb salvage: polytetrafluoroethylene prosthetic bypass.

Polytetrafluoroethylene (PTFE) grafts have proven to be an adequate alternative conduit for peripheral bypass operations. Whether or not one uses PTFE depends on several factors: surgeon preference, individual patient circumstances, or when autologous greater saphenous vein is not available or adequate. These conventional grafts have evolved and undergone modification. The intraluminal surface has been coated with carbon or bonded with heparin. The structure of grafts has been modified with the creation of a hood or cuff, with the incorporation of a stent-graft segment for a sutureless anastomosis, or the fusion of PTFE with an outer polyester layer to minimize suture hole bleeding. This evolution intends to limit graft thrombogenicity, ameliorate the formation of intimal hyperplasia, decrease complications, and improve overall graft patency.

The current status of endovascular repair of abdominal aortic aneurysms (EVAR).

Abdominal aortic aneurysms (AAA) affect close to a quarter of a million people in the United States every year. Intervention is designed to treat the AAA when the patient becomes symptomatic and to prevent the fatality associated with rupture. Physicians and patients should weigh the risks associated with intervention compared to the risk of rupture for the particular size of the aneurysm and the patient's comorbidities. Thus, the decision to intervene, especially in asymptomatic aneurysms, is mostly based on clinical judgment. Endovascular AAA repair (EVAR) is attractive in that it offers a minimally invasive approach that obviates a major abdominal procedure and cross-clamping of aorta. We report on the current affairs of the major clinical trails evaluating the outcomes of patients undergoing EVAR and describe the current devices available in the United States for endovascular repair.

Changing paradigm in endovascular treatment of descending thoracic aortic dissections.

Descending thoracic dissections originating distal to the origin of the left subclavian artery carry a significant mortality if left untreated. Past thinking advocated avoiding surgical treatment of acute Stanford type B or DeBakey type III dissections, reserving therapy for chronic dissections over 14 days to a month after presentation. The current evolution of endovascular devices for the treatment of thoracic aneurysms has proven helpful in treating this pathology in a less invasive manner when compared to open surgical repair. The paradigm for treatment has evolved beyond the nature of the timing of the dissection: the current trend for treatment considers clinical findings and the development of complications. Complicated dissections include those that have developed aneurysmal dilatation >5.5 or 6 cm, organ or distal limb malperfusion, aortic rupture, uncontrolled hypertension even after adequate medical therapy, and persistent pain including rapid expansion of the affected aorta, among others (Table 1). This article reports on the current paradigm involving thoracic endovascular aortic repair (TEVAR) of Stanford type B or DeBakey type III dissections.

Complications of tunneled cuffed hemodialysis catheters in patients with human immunodeficiency virus infection.

PURPOSE: Although increased infectious and thrombotic complications have been reported in patients with human immunodeficiency virus (HIV), little is known regarding hemodialysis catheter-related complications in HIV patients. In this report, we reviewed our experience and complication rates for tunneled cuffed catheters (TCCs) in HIV patients requiring hemodialysis. METHODS: A total of 85 patients with HIV infection underwent TCC placement for hemodialysis between 1996 and 2009. Hospital records were reviewed to determine causes and risk factors for TCC-related complications in HIV patients. For comparison, we studied 85 age- and sex-matched low-risk HIV case controls who received TCC for hemodialysis during the same period. RESULTS: A total of 119 and 102 TCCs were inserted in the HIV and control group, respectively. Total numbers of catheter days in the HIV and control groups were 17,321 and 15,620 days, respectively. The primary unassisted TCC patency rates at 6 months in the HIV and control groups were 74% ± 11% and 86% ± 8%, respectively (NS). There was an increased TCC bacteremia rate in HIV patients compared with control subjects (5.38 vs. 2.66 per 1,000 TCC days, p=0.03). There was also a higher TCC tunnel infection rate in HIV patients compared with control cohorts (3.72 vs. 1.87 per 1,000 TCC days, p=0.04). Factors associated with increased catheter infection rate in HIV patients were 1) low CD4+ lymphocyte counts (<200/mm3), 2) low albumin level (<2.5 g/dl), and 3) history of illicit intravenous drug use. CONCLUSION: TCCs are associated with an increased risk of infection in HIV patients requiring hemodialysis. Moreover, HIV infection is associated with an increased risk of mortality among hemodialysis patients. Hypoalbuminemia, history of intravenous drug use, and low CD4+ lymphocyte counts are associated with increased risk of catheter infection in HIV patients requiring hemodialysis.