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    Timur Sarac

    We evaluated our experience using cryopreserved cadaver vein allografts (CVGs) for infrageniculate revascularization in patients with a history of failed bypass or no suitable autogenous vein. Records of all patients who underwent lower... more
    We evaluated our experience using cryopreserved cadaver vein allografts (CVGs) for infrageniculate revascularization in patients with a history of failed bypass or no suitable autogenous vein. Records of all patients who underwent lower extremity revascularization with CVG for critical limb ischemia were reviewed. Patient demographics, vessel treated, and postoperative course were analyzed. Patients who had a redo cadaver vein bypass were compared to those with a first-time cadaver vein bypass. Cumulative patency rates, limb salvage, mortality, and factors associated with outcomes were determined using the Kaplan-Meier method with Cox proportional hazards. Between January 2000 and December 2006, 66 CVGs were done in 56 patients out of 1,726 total bypasses. There were 36 men and 20 women, and the mean age was 71.67 +/- 10.50 years. Mean follow-up was 12.12 +/- 14.16 months. Seventy-eight percent of patients had previous bypasses, and 50% of all failed bypasses were failed expanded po...
    Octogenarians and nonagenarians are considered the “very old” and are often viewed as one group. Americans are aging, with the proportion of the very old expected to increase from 1.9 per cent of the population to 4.3 per cent in 2050.... more
    Octogenarians and nonagenarians are considered the “very old” and are often viewed as one group. Americans are aging, with the proportion of the very old expected to increase from 1.9 per cent of the population to 4.3 per cent in 2050. This study aimed to underscore the differences in surgical trends, demographics, and outcomes between octogenarians and nonagenarians. The ACS-NSQIP database (2007–2012) was used to derive the type of surgeries, demographics, and outcomes of octogenarian and nonagenarians undergoing nonemergent vascular, orthopedic, and general surgery procedures. Between 2007 and 2012, nonagenarians accounted for an increasing percentage of surgeries (85 to 121 per 10,000 surgeries, relative risk = 1.42; 95% CI: 1.30–1.54) across surgical specialties, including vascular, general, and orthopedic surgery, whereas the percentage of octogenarians undergoing surgery remained unchanged. Nonagenarians had a higher 30-day perioperative mortality and a longer hospital stay th...
    Abdominal aortic aneurysm (AAA) is defined as a permanent dilatation of the abdominal aorta that exceeds 3 cm. Most AAAs arise in the portion of abdominal aorta distal to the renal arteries and are defined as infrarenal. Most AAAs are... more
    Abdominal aortic aneurysm (AAA) is defined as a permanent dilatation of the abdominal aorta that exceeds 3 cm. Most AAAs arise in the portion of abdominal aorta distal to the renal arteries and are defined as infrarenal. Most AAAs are totally asymptomatic until catastrophic rupture. The strongest predictor of AAA rupture is the diameter. Surgery is indicated to prevent rupture when the risk of rupture exceeds the risk of surgery. In this review, we aim to analyze this disease comprehensively, starting from an epidemiological perspective, exploring etiology and pathophysiology, and concluding with surgical controversies. We will pursue these goals by addressing eight specific questions regarding AAA: (1) Is the incidence of AAA increasing? (2) Are ultrasound screening programs for AAA effective? (3) What causes AAA: Genes versus environment? (4) Animal models: Are they really relevant? (5) What pathophysiology leads to AAA? (6) Indications for AAA surgery: Are surgeons over-eager to ...
    Objectives The placement of inferior vena cava filters (IVCF) continues to rise. Vascular specialists adopt different practices based on local expertise. This study was performed to assess the attitudes of vascular specialists towards the... more
    Objectives The placement of inferior vena cava filters (IVCF) continues to rise. Vascular specialists adopt different practices based on local expertise. This study was performed to assess the attitudes of vascular specialists towards the placement and retrieval of IVCF. Methods An online survey of 28 questions related to practice patterns regarding IVCF was administered to 1429 vascular specialists. Vascular specialists were categorized as low volume if they place less than three IVCF per month and high volume if they place at least three IVCF per month. The responses of high volume and low volume were compared using two-sample t-tests and Chi-square tests. Results A total of 259 vascular specialists completed the survey (18% response rate). There were 191 vascular surgeons (74%) and 68 interventional radiologists (26%). The majority of responders were in academic practice (67%) and worked in tertiary care centers (73%). The retrievable IVCF of choice was Celect (27%) followed by D...
    Thermal vein ablation (VA) is the recommended treatment modality for superficial venous reflux, with a recommended positioning of the catheter at 2 to 3 cm from the junction of the deep venous system. In contrast, novel sealing technology... more
    Thermal vein ablation (VA) is the recommended treatment modality for superficial venous reflux, with a recommended positioning of the catheter at 2 to 3 cm from the junction of the deep venous system. In contrast, novel sealing technology for saphenous VA involves treatment starting at 3 to 5 cm distal to the deep junction. This study examines the effect of increasing catheter distance from the junction on the outcomes of VA using radiofrequency. A retrospective single-center review of patients treated with VA was performed. Demographics, symptoms, clinical class (Clinical, Etiology, Anatomy, and Pathophysiology classification), and ultrasound data were reviewed. The treatment groups were divided on the basis of the position of the catheter <3 cm (group A) or ≥3 cm (group B) from the deep junction. Clinical success, technical success, complications, and recurrence were compared between the two groups. Long-term follow-up was collected by telephone survey inquiring about intensity...
    The use of venous ablation (VA) for treatment of chronic venous insufficiency has exponentially increased. To limit cost and overuse, insurance companies have adopted aleatory policies. The goal of this study was to compare the policies... more
    The use of venous ablation (VA) for treatment of chronic venous insufficiency has exponentially increased. To limit cost and overuse, insurance companies have adopted aleatory policies. The goal of this study was to compare the policies of five major local insurance carriers and to determine whether treatment within the criteria of a certain policy is associated with improved patient outcomes. A retrospective single-center review of patients treated with VA was performed. Demographics, comorbidities, symptoms, and clinical class (Clinical, Etiology, Anatomy, and Pathophysiology classification) were recorded. Clinical success was defined on chart review by the patients' reporting of improvement or resolution of symptoms in the leg treated on follow-up, and technical success was defined by vein closure on ultrasound. Patients underwent a telephone survey inquiring about intensity of symptoms on a numeric rating scale of 0 to 10 before and after treatment of each leg as well as eff...
    There is evidence to suggest outcomes may be related to surgeon experience or skill level. Lower extremity amputations are performed by both general surgeons (GSs) and vascular surgeons (VSs); however, the effect of specialty on... more
    There is evidence to suggest outcomes may be related to surgeon experience or skill level. Lower extremity amputations are performed by both general surgeons (GSs) and vascular surgeons (VSs); however, the effect of specialty on postoperative outcome in below-knee amputation is not known. This retrospective study compares outcomes in below-knee amputations (BKA) between VS and GS. Patients who underwent below-knee amputations between 2005 and 2014 were identified from the American College of Surgeons National Surgical Quality Improvement Project database. Data collected included patient demographics, comorbid conditions, and indication for procedures. Univariate and multivariate unconditional logistic regression models and linear regression models were employed to evaluate the associations between various outcomes and indications for surgery, emergency and teaching status, and surgical specialty. Amputations performed by GSs experienced an increased risk of developing pneumonia (odd...
    The Nellix System (Endologix, Inc, Irvine, Calif) for endovascular aneurysm sealing (EVAS) is a novel approach to abdominal aortic aneurysm treatment and conceptually different from endovascular aneurysm repair, whereby polymer is... more
    The Nellix System (Endologix, Inc, Irvine, Calif) for endovascular aneurysm sealing (EVAS) is a novel approach to abdominal aortic aneurysm treatment and conceptually different from endovascular aneurysm repair, whereby polymer is employed to fill and actively manage the abdominal aortic aneurysm sac. One-year safety and effectiveness results of the Nellix pivotal trial demonstrated encouraging outcomes with very low morbidity and mortality and high procedural and treatment success. Two-year imaging revealed a signal of migration, leading to a field safety notification issued by the manufacturer on October 21, 2016, and a dedicated root cause analysis, resulting in refinements to the instructions for use (IFU). We report the 2-year results of the investigational device exemption pivotal trial stratified according to the new and original criteria for selection of patients. Comprehensive engineering evaluations, statistical analyses, and clinical assessments were conducted looking at ...
    The Caprini model estimates patients' risk for venous thromboembolism by 30 different factors. Hemodynamically significant pulmonary embolism (PE), defined as high-risk (massive) or intermediate-risk (submassive) PE, has high... more
    The Caprini model estimates patients' risk for venous thromboembolism by 30 different factors. Hemodynamically significant pulmonary embolism (PE), defined as high-risk (massive) or intermediate-risk (submassive) PE, has high morbidity and mortality rates. This study tests whether the Caprini model and deep venous thrombosis (DVT) characteristics correlate with the prevalence of PE and hemodynamically significant PE in patients with DVT. A retrospective review of patients diagnosed with DVT between January 2013 and August 2014 in a tertiary care center was performed. Multivariable analysis was used to determine predictors of PE and hemodynamically significant PE. Of 838 consecutive patients with DVT, 217 (25.9%) had concomitant PE at presentation, of whom 135 had hemodynamically significant PE (101 submassive PE, 34 massive PE). The mean age was 65 years, and 51.0% were women. There was no significant relation between age or gender and the occurrence of PE or hemodynamically sig...
    May-Thurner syndrome (MTS) is increasingly recognized as a frequent source of leg swelling and a precipitating factor for venous thromboembolism. This paper is a systematic review of the English literature on MTS with an analysis focusing... more
    May-Thurner syndrome (MTS) is increasingly recognized as a frequent source of leg swelling and a precipitating factor for venous thromboembolism. This paper is a systematic review of the English literature on MTS with an analysis focusing on gender differences in presentation and treatment. A systematic review of the English literature between April 1967 and December 2014 was performed using the following terms: "May-Thurner syndrome," "Cockett syndrome," and "iliac vein compression syndrome." After review, there were 174 articles in the analysis. We first analyzed all presented cases, followed by a gender comparison if case reports and case series had detailed description. Asymptomatic patients with just anatomic compression without symptoms were excluded. Statistical differences between data sets were assessed using χtest and Student t-test. There were 1569 patients with MTS after exclusion of articles based on our criteria. The female to male ratio w...
    Endothelial function is improved by l-arginine (l-arg) supplementation in preclinical and clinical studies of mildly diseased vasculature; however, endothelial function and responsiveness to l-arg in severely diseased arteries is not... more
    Endothelial function is improved by l-arginine (l-arg) supplementation in preclinical and clinical studies of mildly diseased vasculature; however, endothelial function and responsiveness to l-arg in severely diseased arteries is not known. Our objective was to evaluate the acute effects of catheter-directed l-arg delivery in patients with chronic lower extremity ischemia secondary to peripheral arterial disease. The study enrolled 22 patients (45% male) with peripheral arterial disease (mean age, 62 years) requiring lower extremity angiography. Endothelium-dependent relaxation of patent but atherosclerotic superficial femoral arteries was measured using a combination of intravascular ultrasound (IVUS) imaging and a Doppler FloWire (Volcano Corporation, Rancho Cordova, Calif) during the infusion of incremental acetylcholine (10(-6) to 10(-4) molar concentration) doses. Patients received 50 mg (n = 3), 100 mg (n = 10), or 500 mg (n = 9) l-arg intra-arterially, followed by repeat endo...
    Functional status is an important predictor of outcomes after infrainguinal bypass surgery. There are little data on the effect of functional status on the outcomes of endovascular lower extremity interventions, especially in the elderly... more
    Functional status is an important predictor of outcomes after infrainguinal bypass surgery. There are little data on the effect of functional status on the outcomes of endovascular lower extremity interventions, especially in the elderly frail population. This is a retrospective analysis of the American College of Surgeons - National Surgical Quality Improvement Program files for the years 2011-2013 to assess the impact of functional status on outcome after endovascular intervention for critical limb ischemia (CLI). Elderly patients (age ≥70) undergoing revascularization for CLI were included. The patients were divided into 2 groups based on functional status prior to surgery: independent (IND) or dependent (DEP), which included partially dependent as well as totally dependent patients. The 2 groups were compared with respect to demographics, comorbidities, complications, length of stay, limb loss, and mortality. Statistical analysis was performed using Student's t-test for continuous variables and Fisher's exact test for categorical variables. There were 1,055 patients (DEP = 253, 24%). There was no difference in gender or race but DEP patients were older than IND (P = 0.008). DEP patients were significantly more likely to have history of congestive heart failure (P = 0.003), hypertension (P = 0.042), and diabetes (P <0.001). There was no difference in emergent surgeries between the 2 groups (P = 1.00). DEP patients had more tibial interventions compared with IND (P <0.001). DEP developed more pneumonia (P <0.001) and septic shock (P = 0.016) and had a trend toward more urinary tract infections (P = 0.051) after endovascular revascularization. There was no significant difference in operating time (P = 0.232) or major amputation (P = 0.092). DEP had significantly longer length of hospital stay (P = 0.0068). DEP had significantly higher mortality (5.98% vs. 2.01%, P = 0.002). On multivariate analysis, DEP status, emergency procedure, congestive heart failure, cardiac arrest requiring cardiopulmonary resuscitation, myocardial infarction, sepsis, and septic shock were independently associated with 30 days of mortality. Irrespective of age, DEP functional status was the most significant preoperative predictor of mortality with an odd ratio of 5.16 [1.93-13.83], P = 0.001 (parsimonious model). Functional status should be carefully assessed when considering endovascular revascularization in the elderly as DEP has significantly higher morbidity and mortality.
    Endovascular aneurysm repair (EVAR) with percutaneous femoral access (PEVAR) has several potential advantages. Morbidly obese (MO) patients present unique anatomical challenges and have not been specifically studied. This study examines... more
    Endovascular aneurysm repair (EVAR) with percutaneous femoral access (PEVAR) has several potential advantages. Morbidly obese (MO) patients present unique anatomical challenges and have not been specifically studied. This study examines the trends in the use of PEVAR and its surgical outcomes compared with open femoral cutdown (CEVAR) in MO patients. The American College of Surgeons National Surgical Quality Improvement Program files for the years 2005 to 2013 were reviewed. The study included all MO patients (body mass index [BMI] ≥40 kg/m(2)) undergoing EVAR. Patients were categorized as having CEVAR if they had any one of 11 selected Current Procedural Terminology (American Medical Association, Chicago, Ill) codes describing an open femoral procedure. The PEVAR group included any remaining patients who had only codes for EVAR and endovascular procedures. Linear correlation was used to evaluate temporal trends in the use of PEVAR among MO patients. Baseline comorbidities and surgi...
    Scrotal hematoma is a rare and unusual complication of transfemoral cardiac catheterization. We describe the case of a 43-year-old man who presented with a delayed retroperitoneal hemorrhage and massive scrotal hematoma following cardiac... more
    Scrotal hematoma is a rare and unusual complication of transfemoral cardiac catheterization. We describe the case of a 43-year-old man who presented with a delayed retroperitoneal hemorrhage and massive scrotal hematoma following cardiac catheterization. Emergent groin exploration was performed with ligation of the inferior epigastric artery and evacuation of the scrotal hematoma. Urological sequelae from transfemoral arterial access are rare. However, scrotal hematoma may occur if bleeding occurs between anatomic fascial planes.

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