Unilateral inline replacement of infected aortofemoral graft limb with femoral vein.

OBJECTIVE: Aortic graft infection remains a formidable challenge for the vascular surgeon. Traditionally, reconstruction with a neoaortoiliac system (NAIS) involves removal of the entire synthetic graft with in situ reconstruction using femoral vein. Whereas the NAIS procedure is durable with excellent graft patency and a low reinfection rate, it can take up to 10 hours and result in a high perioperative complication rate with significant mortality. Not infrequently, the infection is limited to a single limb. In addition, the patient may be too frail to tolerate aortic clamping for a complete graft excision. Under such circumstances, complete excision of the aortofemoral bypass graft (AFBG) may not be indicated. It is hypothesized that local control of infection and limited reconstruction using femoral vein may be acceptable. The objective of this study was to examine the outcomes of all patients who underwent partial AFBG resection and in situ reconstruction with femoral vein. METHODS: A retrospective review of all AFBG infections from 2003 to 2015 treated at a tertiary care facility was undertaken. Patients who underwent unilateral partial graft excision with inline reconstruction using femoral vein at the distal (femoral) anastomosis were included. Complete excisions with bilateral revascularizations using any conduit or any extra-anatomic reconstructions were excluded. The primary end point was successful treatment of infection. Secondary end points were procedure-related mortality, graft patency, and perioperative complications. RESULTS: During a 12-year period, partial graft excision with bypass using the femoral vein was performed in 21 patients (24 limbs). Mean age was 61 ± 12 years. There were 13 men and 8 women. Mean follow-up was 53 ± 27 months. Successful treatment was achieved in 19 of 21 patients. The two treatment failures were due to persistent infection. One of these patients declined complete graft excision and is receiving lifelong suppressive antibiotic therapy. The other patient underwent complete graft excision and an NAIS reconstruction. There were no perioperative or procedure-related deaths. There were no major amputations, and primary graft patency was 92% at 72 months. The most common AFBG culture isolate was Staphylococcus species. Approximately one-third of cultures did not yield any growth. Patients underwent anywhere from 1 to 12 weeks of combined intravenous and oral antibiotic therapy. CONCLUSIONS: This limited series demonstrates excellent graft patency with a low persistent infection rate. Thus, in patients with localized graft infection, partial excision with preservation of the proximal synthetic graft is an acceptable alternative when patient factors preclude complete graft excision.

Defining the type of surgeon volume that influences the outcomes for open abdominal aortic aneurysm repair.

OBJECTIVE: Prior studies have reported improved clinical outcomes with higher surgeon volume, which is assumed to be a product of the surgeon's experience with the index operation. We hypothesized that composite surgeon volume is an important determinant of outcome. We tested this hypothesis by comparing the impact of operation-specific surgeon volume versus composite surgeon volume on surgical outcomes, using open abdominal aortic aneurysm (AAA) repair as the index operation. METHODS: The Nationwide Inpatient Sample was analyzed to identify patients undergoing open AAA repairs for 2000 to 2008. Surgeons were stratified into deciles based on annual volume of open AAA repairs ("operation-specific volume") and overall volume of open vascular operations ("composite volume"). Composite volume was defined by the sum of several open vascular operations: carotid endarterectomy, aortobifemoral bypass, femoral-popliteal bypass, and femoral-tibial bypass. Multiple logistic regression analyses were used to examine the relationship between surgeon volume and in-hospital mortality for open AAA repair, adjusting for both patient and hospital characteristics. RESULTS: Between 2000 and 2008, an estimated 111,533 (95% confidence interval [CI], 102,296-121,232) elective open AAA repairs were performed nationwide by 6,857 surgeons. The crude in-hospital mortality rate over the study period was 6.1% (95% CI, 5.6%-6.5%). The mean number of open AAA repairs performed annually was 2.4 operations per surgeon. The mean composite volume was 5.3 operations annually. As expected, in-hospital mortality for open AAA repair decreased with increasing volume of open AAA repairs performed by a surgeon. Mortality rates for the lowest and highest deciles of surgeon volume were 10.2% and 4.5%, respectively (P < .0001). A similar pattern was observed for composite surgeon volume, as the mortality rates for the lowest and highest deciles of composite volume were 9.8% and 4.8%, respectively (P < .0001). After adjusting for patient and hospital characteristics, increasing composite surgeon volume remained a significant predictor of lower in-hospital mortality for open AAA repair (odds ratio, 0.994; 95% CI, .992-.996; P < .0001), whereas increasing volume of AAA repairs per surgeon did not predict in-hospital deaths. CONCLUSIONS: The current study suggests that composite surgeon volume-not operation-specific volume-is a key determinant of in-hospital mortality for open AAA repair. This finding needs to be considered for future credentialing of surgeons.

Predictors of outcome for renal artery stenting performed for salvage of renal function.

OBJECTIVE: To identify preoperative clinical features that predict a durable improvement in renal function with renal artery stenting (RAS). METHODS: Sixty-one patients with renal insufficiency (serum creatinine ≥ 1.5 mg/dL) underwent RAS for renal salvage. Patients were categorized as "responders" if estimated glomerular filtration rate (eGFR) at last follow-up was improved 20% or more over baseline. Patients with stable or worse renal function after RAS were labeled "non-responders." For the purpose of calculating changes in eGFR, patients on dialysis were represented by an eGFR of 10 ml/min/1.73 m(2). Renal volume was estimated as kidney length × width × depth/2. RESULTS: The median age of the cohort was 66 years (interquartile range [IQR], 60-73 years). Median preoperative serum creatinine was 1.8 mg/dL (IQR, 1.6-2.3), and median estimated glomerular filtration rate (eGFR) was 34 mL/min/1.73 m(2) (IQR, 24-45). With stenting, 17 of 61 patients (27.9%) derived a durable improvement in renal function at a median follow-up of 24 months (IQR, 16-33 months). The largest proportion of stented patients (44.3%) had no improvement in renal function after stenting, while a subset (27.9%) experienced a decline in renal function. Responders enjoyed a 47% improvement in renal function from baseline, while non-responders had a 13% decrement in renal function (P < .0001). Responders had a higher baseline serum creatinine, lower eGFR, and a steeper decline in renal function prior to RAS, compared with non-responders. Kidney length, width, depth, and volume were not significantly different between responders and non-responders. Logistic regression analysis identified the rate of decline of renal function prior to stenting as the only independent preoperative predictor of improved renal function after RAS (odds ratio, 3.4; 95% confidence interval, 1.6 to 7.5; P = .0019). The rate of decline in eGFR per week was more than 20-fold greater for responders than non-responders (2.1% vs 0% decline in eGFR per week; P < .0001). No predictors of renal function deterioration after stenting were identified. CONCLUSIONS: The current study found that a steep decline in preoperative renal function portends a higher likelihood of renal salvage from RAS among patients with renal insufficiency. Incorporating this finding into patient selection may improve outcomes for RAS.

Randomized clinical trial of open-cell vs closed-cell stents for carotid stenting and effects of stent design on cerebral embolization.

OBJECTIVE: The effect of stent design on cerebral embolization has not been established. The purpose of this trial was to contrast the incidence of subclinical cerebral embolization in high-risk patients undergoing carotid artery stenting (CAS) with open-cell vs closed-cell stents. METHODS: During an 18-month period, 40 patients were randomized (1:1) to undergo CAS with open-cell (Acculink, n = 20) or closed-cell stents (Xact, n = 20). A single filter device for embolic protection (Accunet filter) was used. Transcranial Doppler (TCD)-detected microembolic signals (MES) during CAS and preprocedural and 24-hour postprocedural diffusion-weighted magnetic resonance imaging (DW-MRI) were used to determine cerebral embolization. Univariate and nonparametric analyses were used to assess associations between stent design and cerebral embolization. RESULTS: CAS was performed in 17 symptomatic patients (43%) and 23 asymptomatic patients (57%) with a similar number of open-cell and closed-cell stents (9/8 and 11/12, respectively). The total and poststenting median ipsilateral MES counts detected by TCD were 264 (interquartile range [IQR], 222-343) and 48 (IQR, 41-66) for open-cell stents and 339 (IQR, 163-408) and 53 (IQR, 23-88) for closed-cell stents, respectively (P > .56). New acute cerebral emboli detected with DW-MRI occurred in 53% and 47% of patients undergoing CAS with open-cell and closed-cell stents, respectively (P = 1.0). The total and ipsilateral median numbers of DW-MRI lesions between groups were not statistically significantly different (ie, 2 [IQR, 0-4] and 1 [IQR, 0-3] for open-cell stents and 1 [IQR, 0-3] and 1 [IQR, 0-2] for closed cell-stents, respectively; P > .4). One asymptomatic patient undergoing CAS with an open-cell stent sustained a minor stroke; the 30-day stroke-death rate in this series was 2.5%. CONCLUSION: Cerebral embolization, as detected by TCD and DW-MRI, occurs with similar frequency after CAS with open-cell and closed-cell stents. This randomized trial does not support the superiority of any stent design with respect to cerebral embolization.

Hand ischemia associated with elbow trauma in children.

OBJECTIVES: Previous observational studies suggest that children with hand ischemia following elbow trauma can be safely observed if Doppler signals are present in the wrist arteries (pink pulseless hand, PPH). Nonoperative management of PPH is predicated on the assumption that PPH results from local arterial spasm, but the mechanism of arterial compromise has not been investigated. We hypothesized that PPH signifies a brachial artery injury that requires surgical repair. METHODS: Retrospective review of operations performed on children with hand ischemia following elbow trauma at a level I trauma center pediatric hospital. RESULTS: Between 2003 and 2010, 12 children (seven males, mean age 7.4 years) underwent brachial artery exploration for hand ischemia following elbow trauma (11 supracondylar fractures, one elbow dislocation) due to falls (n = 10) or motor vehicle crashes (n = 2). At presentation, three subjects had normal radial pulses, eight subjects had Doppler signals but no palpable pulses, and one had weak Doppler flow with advanced hand ischemia. Six of the nine subjects without palpable pulses also had neurosensory changes. All 12 subjects underwent brachial artery exploration either initially (n = 2) or following orthopedic fixation (n = 10) due to persistent pulselessness. At operation, eight of 12 patients (67%) had focal brachial artery thrombosis due to intimal flaps, and four had brachial artery and median nerve entrapment within the pinned fracture site. At discharge, all 12 subjects had palpable radial pulses, but three with entrapment had dense median nerve deficits. One of the three subjects with dense neurologic deficit had complete recovery of neurologic function at ten months. The other two subjects had residual median nerve deficits with partial recovery at 5 and 6 months follow-up, respectively. No patient developed Volkman's contracture. CONCLUSIONS: Brachial artery injuries should be anticipated in children with hand ischemia associated with elbow trauma. Neurovascular entrapment at the fracture site is a possible complication of orthopedic fixation. Absence of palpable wrist pulses after orthopedic fixation should prompt immediate brachial artery exploration. PPH should not be considered a consequence of arterial spasm in these patients.

Clinical and kidney morphologic predictors of outcome for renal artery stenting: data to inform patient selection.

BACKGROUND: The purpose of the current study was to identify clinical and kidney morphologic features that predict a favorable blood pressure (BP) response to renal artery stenting (RAS). METHODS: The study cohort consisted of 149 patients who underwent primary RAS over 9 years. Patients were categorized as "responders" based on modified American Heart Association guidelines: BP <160/90 mm Hg on fewer antihypertensive medications or diastolic BP <90 mm Hg on the same medications. All other patients were deemed "nonresponders." Renal volume was estimated as kidney length × width × depth/2 based on preoperative computed tomography or magnetic resonance scans. Median follow-up was 19 months (interquartile range [IQR] 10.0-29.5 months). RESULTS: The median age of the cohort was 68 years (IQR, 60-74 years). A favorable BP response was observed in 50 of 149 patients (34%). Multivariate analysis identified three independent predictors of a positive BP response: (1) requirement for four or more medications (odds ratio, 29.9; P = .0001), (2) preoperative diastolic BP >90 mm Hg (OR, 31.4; P = .0011), and (3) preoperative clonidine use (OR, 7.3; P = .029). The BP response rate varied significantly based on the number of predictors present per patient (P < .0001). Among patients with three-drug hypertension, a larger ipsilateral kidney (volume ≥150 cm(3)) increased the BP response rate more than threefold compared with patients with smaller kidneys (63% vs 18% BP response rate; P = .018). CONCLUSIONS: The current study demonstrated that three clinical predictors (≥4 antihypertensive medications, diastolic BP ≥90 mm Hg, and clonidine use) are preoperative predictors of BP response to RAS. Kidney volume may help in discriminating responders from nonresponders among those patients with three-drug hypertension. These parameters may assist clinicians in patient selection and provide more concrete data with which to counsel patients on the likely outcomes for RAS.

Hybrid repair of thoracoabdominal aortic aneurysms involving the visceral vessels: comparative analysis between number of vessels reconstructed, conduit, and gender.

BACKGROUND: Thoracoabdominal aortic aneurysm (TAAA) repairs are technically challenging. The advent of endovascular aneurysm repair in combination with visceral/renal artery bypasses has allowed for hybrid endovascular repair of these aneurysms. The purpose of this study was to evaluate whether outcomes were affected by the number of visceral/renal artery reconstructions, conduit, or gender. METHODS: All patients who underwent visceral/renal bypass associated with an endovascular aortic aneurysm repair were prospectively studied in a vascular registry and retrospectively reviewed between the years 2004 and 2009. Patients undergoing standard open TAAA repair and those with aortic arch branch vessel reconstructions associated with thoracic endovascular repair were excluded from this analysis. Patients were segregated into two groups on the basis of number of vessels bypassed. Group 1 (n = 9) consisted of patients who required one or two bypasses, whereas group 2 (n = 15) consisted of patients who required three or four bypasses. RESULTS: A total of 64 TAAA repairs were performed. In all, 22 patients with hybrid repair and aortic arch vessel reconstructions and 18 patients with open TAAA repair were excluded from this analysis. A total of 24 (38%) patients with hybrid endovascular repair were evaluated in this study. The 30-day mortality was found to be 12.5% (3/24) and the incidence of spinal cord ischemia was 8.3% (2/24). Preoperative comorbidities and American Society of Anesthesia (ASA) scores were reported to be similar between the two groups. As compared with group 2, patients in group 1 were reported to be younger (69.7 ± 10.6 vs. 76.0 ± 5.7 years [p = 0.074]), had less blood loss (1,200 ± 1,088 mL vs. 3,119 ± 2,188 mL, [p = 0.06]), required fewer blood transfusions (5.33 ± 2.31 vs. 9.09 ± 7.06 units packed red blood cells (PRBC) [p = 0.39]), and had a shorter length of stay (11.4 ± 5.6 vs. 21.9 ± 15.1 days, [p = 0.090]). There was no difference in 30-day mortality rates between the two groups. The incidence of perioperative morbidity, including bowel ischemia (11%[1/9] vs. 27% [4/15], [p = 0.39]), myocardial infarction (11% [1/9] vs. 13% [2/15], [p = 0.88]), wound infection (0% vs. 27% [4/15], [p = 0.09]), and pneumonia (11% [1/9] vs. 40% [6/15], [p = 0.14]) was found to be less in group 1 than group 2, but this difference was not significant. Patients with three or four bypasses had a significantly greater requirement for a skilled nursing facility or a rehabilitation facility after discharge (79% [11/14] vs. 29% [2/7], p = 0.026). There were no statistically significant differences in postoperative outcomes when comparing choice of conduit (autogenous or prosthetic) or gender. Results from the Cox-proportional hazards regression showed that bowel ischemia was the only postoperative complication associated with decreased survival (p = 0.037, confidence interval [0.1328-4.3075]). CONCLUSIONS: Hybrid aortic aneurysm repair carries a significant risk of patient morbidity with an acceptable mortality for patients considered to be at a high risk for standard thoracoabdominal repair. In patients requiring fewer visceral/renal reconstructions, there is a trend toward fewer postoperative complications and a significantly shorter length of stay. Moreover, there is a significantly lower need for skilled nursing facility requirements after discharge from the hospital. Bowel ischemia is associated with significantly worse outcome and better attempts at avoiding this complication and aggressive management is indicated.

Neoaortoiliac System (NAIS) procedure for the treatment of the infected aortic graft.

We aim to provide a thorough and current summary highlighting the use of autologous vein grafts during reconstruction of infected aortic grafts. Aortic graft infections, while rare, remain one of the most difficult problems that a vascular surgeon can encounter. Optimal management of patients with aortic graft infections requires a full understanding of all potential therapeutic interventions available. Reconstruction with autologous vein grafts is a technique that has evolved and has been refined during the past 2 decades, representing a major advance in the treatment of aortic graft infections. Thirty-day operative mortality is ≤ 10%, with 5-year mortality rates of 30% to 50%. Thirty-day major amputation rates range from 2% to 7.4%, with 5-year limb-salvage rates ranging between 89% and 96%. Early occlusion of the grafts are rare, with <4% undergoing thrombosis within the first 30 days; 5-year primary patency ranges from 75% to 91%, with secondary patency approaching 91% at 5 years. Recurrent infection is very rare, occurring in <2% of patients. Venous morbidity is similarly low, with fasciotomy rates of 12%, and only 15% of patients experiencing chronic venous insufficiency at 5 years. Aneurysmal degeneration is also exceptionally rare. Use of autologous vein grafts for in situ reconstruction of infected aortic grafts represents the standard of care in the treatment of aortic graft infections. With appropriate patient selection, centers with sufficient resources should be able to comparable outcomes.

Atherosclerotic plaque composition assessed by virtual histology intravascular ultrasound and cerebral embolization after carotid stenting.

OBJECTIVE: Previous studies have investigated the predictive value of clinical and morphologic parameters for distal embolization during carotid interventions. The composition of the atherosclerotic plaque, using virtual histology intravascular ultrasound (VH-IVUS) imaging obtained with an IVUS catheter that is advanced through the lesion after a filter has been placed distally, has not been evaluated as a marker for cerebral embolization. The purpose of this study was to assess the relationship between atherosclerotic plaque composition determined with VH-IVUS and the occurrence of cerebral embolization after carotid artery stenting (CAS). METHODS: During a 10-month period, 24 patients undergoing CAS procedures using a filter device for embolic protection were prospectively evaluated. All patients underwent VH-IVUS exams at the time of the intervention, transcranial Doppler (TCD) monitoring during CAS, and pre- and 24-hour postprocedural diffusion-weighted magnetic resonance imaging (DW-MRI) exams. Using VH-IVUS, plaque components were characterized as fibrotic, fibrofatty, dense calcium, and necrotic core. The frequency of Doppler-detected microembolic signals (MES) during CAS and the incidence and location of acute postprocedural embolic lesions detected with DW-MRI were assessed to determine cerebral embolization. Univariate and correlation analyses were used to assess the association between plaque composition and frequency of cerebral embolization. RESULTS: No periprocedural transient ischemic attacks, strokes, or deaths occurred within 30 days. Seventeen patients (71%) demonstrated new acute cerebral emboli in DW-MRI. Of these, all revealed ipsilateral lesions and 12 (50%) had contralateral lesions. For the entire study group, the median number of ipsilateral DW-MRI lesions was 1 (range, 0 to 3), and TCD MES counts were 227 (interquartile range, 143-315). Volumetric VH-IVUS analysis revealed that there was a trend for larger median dense calcium volume in patients with ipsilateral subclinical cerebral embolism detected with DW-MRI (33.2±24.5 mm3 vs 11.4±6.1 mm3; P=.08). Scatter plots of plaque components revealed statistically significant correlation between fibrofatty plaque volume (Spearman r=0.49; P=.016) and number of new ipsilateral lesions in DW-MRI. Degree of cerebral embolization during CAS measured with TCD correlated with plaque burden, necrotic core, fibrofatty, and fibrous volumes. CONCLUSIONS: Plaque composition, as determined by VH-IVUS, only weakly correlates with the degree of cerebral embolization after carotid stenting. Specifically, there is a trend for larger dense calcium volume in patients with distal embolization. Of note, the proportion of necrotic core, which has traditionally been considered the main component of a vulnerable or unstable plaque, is not definitely associated with subclinical cerebral embolization after CAS when a filter device for embolic protection is used. The role of VH-IVUS in evaluating plaque composition during CAS remains unestablished and warrants further investigation.

The limitations of thoracic endovascular aortic repair in altering the natural history of blunt aortic injury.

BACKGROUND: Thoracic endovascular aortic repair (TEVAR) is accepted treatment for blunt aortic injury (BAI). We hypothesized that immediate TEVAR would reduce deaths from aortic rupture in patients with BAI. METHODS: Review of 81 patients with BAI who arrived alive at a level I trauma center over a 10-year period. RESULTS: Twenty-three patients (28%) died within 4 hours of admission, including 12 who died of aortic rupture. Fifty-eight patients (72%) survived beyond 4 hours, and 8 (14%) ultimately died of associated injuries. Forty patients (69%) underwent aortic repair (30 open repair, 10 TEVAR), and 2 died of multisystem organ failure (MSOF). Comparing open repair to TEVAR, there were no differences in the length of hospital stay (33 +/- 27 vs 33 +/- 31 days), operative complications (77% vs 70%), or mortality (7% vs 0). Ten patients (17%) with minimal BAI were treated with beta blockade and observation; 4 have not healed their aortic injuries and 6 have been lost to follow-up. Thirty-three of the original 81 study patients (41%) ultimately died. Compared with the patients who died, the survivors were younger (37 vs 48 years; P = .01) and less likely to develop aortic rupture (0 vs 12; P < .001), require intubation in the field (27% vs 49%; P < .05), require cardiopulmonary resuscitation (CPR; 2% vs 30%; P < .001), or arrive hypotensive (17% vs 67%; P < .001). Survivors also had a lower mean injury severity score (34 +/- 12 vs 44 +/- 12; P < .001), fewer associated injuries (3 +/- 1 vs 4 +/- 3; P = .02), and a higher prevalence of aortic repair (79% vs 6%; P < .001). Multivariate analysis selected no attempt at aortic repair (odds ratio [OR], 90.9; 95% confidence interval [CI], 10.6-1000) and hypotension on arrival (OR, 6.1; 95% CI, 1.4-27) as the only independent variables associated with death. CONCLUSION: Mortality remains high for patients with BAI, but most patients who arrive alive at the hospital do not experience aortic rupture. Rupture occurs within the first 4 hours of admission, often before the injury is recognized in time for salvage with immediate TEVAR. The decision to repair BAI was based on the extent of associated injuries and on the individual surgeon's judgment. Survival was not influenced by the timing of repair, but further studies are needed to compare the outcome of open repair vs TEVAR in patients who survive beyond 4 hours.

Effects of ethnicity and insurance status on outcomes after thoracic endoluminal aortic aneurysm repair (TEVAR).

BACKGROUND: Thoracic endoluminal aortic aneurysm repair (TEVAR) is associated with improved outcomes compared with open thoracic aortic aneurysm repair. This study was designed to better characterize TEVAR outcomes in a large population, and to determine if outcomes are independently influenced by patient ethnicity and insurance status. METHODS: Using the Nationwide Inpatient Sample (NIS) database, we selected patients who underwent TEVAR between 2001 and 2005. Ethnicity and insurance type were independently evaluated against the outcome variables of mortality and postoperative complications. Age, gender, hospital region, hospital location, hospital size, and comorbidities were controlled as cofounders. RESULTS: Between 2001 and 2005, 875 patients underwent TEVAR. There was a significantly greater proportion of Caucasians (n = 650) compared with African Americans (n = 104) or Hispanics (n = 49). Patients had a male preponderance, and most procedures were elective. The overall mortality was 13.3% (n = 117), and spinal cord ischemia was 0.8% (n = 7), with no differences between patients of varied ethnicity or payer status. Significant differences were noted among the races including gender (P = .003), income (P < .0001), hospital region (P < .001), hospital bed size (P = .013), and insurance type (P < .001). Significant variations in demographics characteristics were also present between patients with different insurance classifications including gender (P < .001), surgery type (P = .009), income (P = .003), race (P < .0001), and comorbidity index (P < .0001). After adjustment for cofounders and multiple comparisons, there were no differences in rates of complications among patients with varying race or insurance status. CONCLUSIONS: Mortality after TEVAR remains high in the US, although this may be associated with its early introduction during the study period. Nonetheless, the incidence of spinal cord ischemia is very low. Ethnicity and insurance type do not appear to influence TEVAR outcomes.

A systematic review of the limitations and approaches to improve detection and management of peripheral arterial disease in Hispanics.

Peripheral arterial disease (PAD) is a highly prevalent public health problem associated with major detrimental effects on quality of life and functional status, and it is also the main cause of limb amputation. More importantly, PAD has been classified as a coronary artery disease equivalent, meaning that patients with a diagnosis of PAD carry a risk for major coronary events equal to that of established coronary artery disease. PAD is also a potent predictor of stroke and death. Despite its frequent occurrence (8 to 10 million Americans are affected), little is known about the natural history of PAD in racial/ethnic minorities, particularly in Hispanics, who represent 12.5% of the United States population. Furthermore, the disease is commonly underdiagnosed and undertreated in this minority group, and outcomes are poorer in Hispanics as compared with whites. Limited access to health care, difficulties for recruitment in population-based studies, and limitations of the noninvasive screening tests are well-established barriers to determine the prevalence and natural history of PAD in Hispanics. Although the most widely used test for assessment of patients at risk for PAD is the ankle-brachial index (ABI), the test has substantial limitations in individuals with diabetes and arterial calcification, which are highly prevalent in Hispanics. The ABI should, therefore, be supplemented by the use of other noninvasive tests, such as the pulse volume recordings (PVR) and toe-brachial index. Besides the use of a combination of diagnostic techniques, the implementation of a research methodology that improves recruitment of Hispanics in population-based studies is necessary to obtain better knowledge of the epidemiology of the disease in this group. Community-based participatory research may be the most appropriate approach to study this ethnic minority because it overcomes barriers for limited access to health care and increases the possibility of overcoming distrust of research on the part of communities. Understanding the epidemiology of PAD to improve its detection and treatment among Hispanics is relevant to reduce disparities in the health status of this group, the most rapidly growing ethnic minority in the United States.

Long-term results of the treatment of aortic graft infection by in situ replacement with femoral popliteal vein grafts.

OBJECTIVE: Graft excision and neo-aortoiliac system (NAIS) reconstruction with large caliber, femoral popliteal vein (FPV) grafts have been reported as successful treatment of aortic graft infection (AGI) in several small series with limited follow-up. The goal of this study was to evaluate long-term outcomes in large cohort of consecutive patients treated with NAIS for AGI. METHODS: From 1990 to 2006, 187 patients (age: 63 +/- 10 years) with AGI were treated with in situ reconstructions using 336 FPV grafts. Data from a prospectively maintained data base were analyzed. RESULTS: NAIS reconstruction was performed for 144 infected aortofemoral bypasses, 21 infected aortic-iliac grafts, and 22 infected axillofemoral bypasses that had been placed to treat AGI. Polymicrobial cultures were present in 37% while 17% showed no growth. There were 55% gram positive, 32% gram negative, 13% anaerobic, and 18% fungal infections. The mean Society for Vascular Surgery run-off resistance score was 4.5 +/- 2.3. Concomitant infrainguinal bypass was necessary in 27 (14%) patients (32 limbs). Major amputations were performed in 14 (7.4%) patients. Out of 14 amputations, five patients had irreversible ischemia and in four, there was no conduit available. Graft disruption from reinfection occurred in 10 patients (5%). While 30-day mortality was 10%, procedure-related mortality was 14%. Independent risk factors for perioperative death on multivariate analysis were: preoperative sepsis (odds ratio [OR] 3.5) ASA class 4 (OR 2.9), Candida species (OR 3.4), Candida glabrata (OR 7.6), Klebsiella pneumoniae (OR 3.5), and Bacteroides fragilis (OR 4.1). Perioperative factors included use of platelets (OR 2.4), blood loss >3.0 liters (OR 9.5). Cumulative primary patency at 72 months was 81%; secondary/assisted primary patency was 91%. Limb salvage at 72 months was 89%. Five-year survival was 52%. CONCLUSIONS: These results compare favorably with other methods of treating AGI, especially in patients with multilevel occlusive disease. Principle advantages include acceptable perioperative mortality, low amputation rate, superior durability with excellent long-term patency, and freedom from secondary interventions and recurrent infections.

Effect of hospital volume on in-hospital mortality for renal artery bypass.

BACKGROUND: A recent report determined that the nationwide mortality for renal artery bypass (RAB) is surprisingly high-10%. We hypothesized that operative mortality for RAB is related to the volume of such operations performed in each center. METHODS: The Nationwide Inpatient Sample was analyzed to identify patients undergoing RAB for the years 2000-2005. In-hospital mortality for RAB was compared between hospitals. RESULTS: During the study period, RAB was performed on 7413 patients with an overall in-hospital mortality of 9.6%. The multivariate logistic regression analyses revealed that after adjusting for surgical risk, increasing hospital volume was significantly associated with decreased in-hospital mortality for RAB (odds ratio 0.98; 95% confidence interval, 0.96-0.99; P=.015). CONCLUSIONS: Patient risk profile and hospital volume are critical determinants of in-hospital mortality for RAB, which should be factored into decision making for patients requiring intervention for renovascular disease.

Trends in workforce diversity in vascular surgery programs in the United States.

BACKGROUND: U.S. black and Hispanic populations are growing at a steady pace. In contrast, the medical profession lacks the same minority growth and representation. Women are also under-represented in many surgical disciplines. The purpose of this study was to assess trends in the proportion of women, blacks, and Hispanics admitted to vascular surgery (VS) and related specialties, and to compare them with each other and with a surgical specialty, orthopedic surgery (OS), with a formal diversity initiative. METHODS: Data on the fellowship pool of VS, interventional radiology (IR), and interventional cardiology (IC), as well as the resident pools of general surgery (GS) and orthopedic surgery (OS), were obtained from U.S. graduate medical education reports for 1999 through 2005. Cochrane-Armitage trend tests were used to assess trends in the proportion of females, blacks, and Hispanics in relation to the total physician workforce for each subspecialty. RESULTS: No significant trends in the proportion of females, blacks, or Hispanics accepted into VS and IC fellowship programs occurred during the study period. In contrast, IR, GS, and OS programs revealed significant trends for increasing proportions of at least one of the underrepresented study groups. In particular, OS, which has implemented a diversity awareness program, showed a positive trend in female and Hispanic trainees (P < .04 and P < .02, respectively). Blacks showed a significant increasing trend only in IR (P = .05). Conversely, a positive trend toward continued growth in the Hispanic group was seen in GS (P < .001), IR, and OS (P = .04 and P = .02, respectively). CONCLUSIONS: The racial/ethnic and gender composition of the physician trainee pool in vascular specialties, particularly VS, has not matched the increasing growth of underrepresented groups in the US population of patients with vascular disease. Formal programs to recruit qualified women and minorities appear successful in increasing workforce diversity.

Combined aortic debranching and thoracic endovascular aneurysm repair (TEVAR) effective but at a cost.

OBJECTIVES: To compare hybrid repair (HR) (aortic debranching and TEVAR) with conventional open thoracoabdominal and aortic arch repairs (OR), including a cost analysis. DESIGN: Retrospective cohort. SETTING: University hospital. PATIENTS: Thirty patients with thoracoabdominal aneurysms were evaluated between November 1, 2005, and December 31, 2006. INTERVENTIONS: There were 18 HRs and 12 ORs. Aortic abnormalities included the arch, visceral aorta, and arch/visceral aorta combined. Aortic debranching with TEVAR (HR) was performed at a single setting. Dacron grafts were used for OR, and branch vessels were bypassed. Hospital costs and reimbursements were obtained from the finance department. MAIN OUTCOME MEASURES: Perioperative morbidity, mortality, and cost. RESULTS: Patients were significantly older in the HR group (mean [SD], 72 [8.9] vs 58 [17.4] years, P = .2). The HR group had significantly less blood loss (mean [SD], 1.7 [2.3] vs 4.8 [3.1] L, P = .004), transfusions (5.1 [5.9] vs 14.7 [7.8] units, P = .001), renal failure (0% vs 42.0%, P = .002), and pulmonary morbidity (17% vs 67%, P < .001); shorter intensive care unit stays (5.2 [4.8] vs 16.4 [12.9] days, P = .005); and shorter hospital length of stay (mean [SD], 11.6 [6.2] vs 20.8 [10.8] days, P = .01). There were no differences in mortality or spinal cord ischemia. There was no difference in mean direct hospital costs (HR: $59,435.70 vs OR: $49,341; P = .35). However, the mean cost margin per case was -34% for HR and +6.2% for OR (P = .04). CONCLUSIONS: Improved clinical outcomes are seen after HR despite treatment of an older, sicker patient population. However, HR ultimately comes at a significant cost to the hospital, with a 34% loss in revenue per case.

Open-cell versus closed-cell stent design differences in blood flow velocities after carotid stenting.

OBJECTIVE: The differential effect of open-cell vs closed-cell stent design configuration on carotid velocities detected by duplex ultrasound (DUS) imaging has not been established. To identify possible stent design differences in carotid velocities, we analyzed DUS studies obtained before and immediately after carotid artery stenting (CAS). METHODS: In a series of 141 CAS procedures performed during a 3-year period, data from the first postinterventional DUS images and carotid angiograms were evaluated for each patient. Peak systolic velocities (PSV), end-diastolic velocities (EDV), and internal carotid artery/common carotid artery (ICA/CCA) PSV ratios were compared according to stent design. Differences in carotid velocities were analyzed using nonparametric statistical tests. RESULTS: Completion angiograms revealed successful revascularization and <30% residual stenosis in each case. The 30-day stroke-death rate in this series was 1.6% and was unrelated to stent type. Postintervention DUS images were obtained a median of 5 days (interquartile range [IQR], 1-25 days) after CAS. Closed-cell stents were used in 41 procedures (29%) and open-cell stents in 100 (71%). The median PSV was 95.9 cm/s (IQR, 77-123 cm/s) for open-cell stents and 122 cm/s (IQR, 89-143 cm/s) for closed-cell stents, which was significantly higher (P = .007). Closed-cell stents also had significantly higher median EDVs (36 vs 29 cm/s; P =.006) and ICA/CCA PSV ratios (1.6 vs 1.1; P =.017). By DUS criteria, the carotid velocities in 45% of closed-cell stents exceeded the threshold of 50% stenosis for a nonstented artery compared with 26% of open-cell stents (P =.04). Closed-cell stents had a 2.2-fold increased risk of yielding abnormally elevated carotid velocities after CAS compared with open-cell stents (odds ratio, 2.2; 95% confidence interval, 1.02-4.9). CONCLUSIONS: Carotid velocities are disproportionately elevated after CAS with closed-cell stents compared with open-cell stents. This suggests that the velocity criteria for quantifying stenosis may require modification according to stent design. The importance of these differences in carotid velocities related to stent design and the potential relationship with recurrent stenosis remains to be established.