Intravascular ultrasound imaging for diagnosis and characterization of the popliteal compression syndrome.

Objective: Functional popliteal artery entrapment syndrome (fPAES) is a rare form of nonatherosclerotic claudication most often seen in young athletic patients. Diagnosis remains challenging, with various imaging modalities showing equivocal or subtle findings that may be missed. We sought to critically examine and quantitate the utility of intravascular ultrasound (IVUS) imaging, a common diagnostic tool for vascular compression syndromes, in diagnosis and characterization of fPAES. Methods: Patients presenting to a single tertiary care center between 2019 and 2022 with symptoms of PAES but without an anatomic etiology or equivocal workup were selected. Angiogram and IVUS with maneuvers were performed on affected extremities at rest, active plantarflexion/dorsiflexion, and plantarflexion/dorsiflexion against resistance. IVUS examination was recorded using a pull-back technique from the tibial vessels to the superficial femoral artery. The degree, length, and anatomic location of compression using the two imaging modalities were compared. Results: Angiogram and IVUS with maneuvers were performed on 17 lower extremities (9 left, 8 right) in 15 patients (88% female; mean age, 21.2 years). Evidence of arterial compression on angiography was noted in 88.2% (n = 15) of limbs (66.7% complete contrast cessation and 20% popliteal artery tapering); 13.3% (n = 2) only demonstrated sluggish flow as possible evidence of compression. Arterial compression was seen on IVUS imaging in 15 of 17 limbs, and all completely compressed around the IVUS catheter. The IVUS-measured mean length of compression was 10.5 cm ± 4.2 (median, 11 cm; range, 4-23 cm). Compression involved only the popliteal vessels in 86.7% (n = 13); one patient had both popliteal and tibioperoneal trunk compression, whereas another had tibioperoneal trunk and peroneal artery compression. Popliteal vein compression was 100%. The contrast cessation point on angiography and the proximal point of compression on IVUS imaging differed in 80% of cases (P < .05). The distal extent of compression was unable to be determined by angiogram findings but was clearly delineated by IVUS imaging in all cases. Conclusions: IVUS imaging is a more sensitive diagnostic and descriptive imaging modality compared with angiogram in patients with possible fPAES. IVUS and angiogram findings are greatly discordant; moreover, IVUS imaging can provide detailed information such as the precise extent and anatomic location of the arterial compression, which may be useful in aiding surgical planning. IVUS imaging should be considered the gold standard for diagnosing and characterizing fPAES before intervention planning.

Direct aortic access for endovascular thoracoabdominal aneurysm repair using a bifurcated endograft as a branched device.

Aortic aneurysms (AA) are a common complication in patients with large-vessel vasculitis, such as chronic phase Takayasu arteritis, that often require surgical management to prevent a lethal rupture. Historically, mainstay of treatment for AA in the setting of arteritis was traditional open repair. However, in this case study an alternative surgical approach was devised to successfully treat an extent III thoracoabdominal AA in a patient with a diagnosis of Takayasu arteritis and a complex surgical history that made her high risk for an open surgical intervention. This case study summarizes a hybrid surgical approach that successfully excluded a thoracoabdominal AA and revascularized the superior mesenteric artery and left renal artery, by directly accessing the infrarenal aorta and using a bifurcated abdominal aortic endograft as a two-vessel branched device.

Center volume is associated with diminished failure to rescue and improved outcomes following elective open abdominal aortic aneurysm repair.

OBJECTIVE: Conflicting annual procedure volumes have been endorsed among different watchdog groups and professional societies, obscuring credentialing paradigms. There has been ample focus on surgeon volume to date but less attention on the effect of center volume. Specifically, whether center volume might be a better proxy for high-quality care. In the present study, we aimed to measure the association of center volume on open abdominal aortic aneurysm (AAA) repair (OAR) outcomes and failure to rescue (FTR). METHODS: All elective OARs (2003-2020) in the Society for Vascular Surgery Vascular Quality Initiative were reviewed (n = 9791). FTR was defined as in-hospital death after the occurrence of a complication (ie, cardiac, stroke, pulmonary, renal, colonic ischemia, return to the operating room for bleeding). The annual center volume for 218 hospitals was calculated, and the volume quartiles (quartile 1 [Q1], ≤3 procedures/y; quartile 2 [Q2], 4-6 procedures/y; quartile 3 [Q3], 7-10 procedures/y; quartile 4 [Q4], >10 procedures/y) were derived for comparison. Logistic regression was used to estimate the effect of center volume and determine the predictors of FTR. RESULTS: The center volume quartiles and incidence of FTR varied significantly (Q4, 2.5% vs Q1 and Q2, 4.9%; P < .0001; overall FTR, 3.1% [n = 302]). The patients were demographically similar among the quartiles. High-volume centers had used epidural anesthesia more often (Q4, 53%; vs Q1, 31%; P < .0001) but were less likely to use thrombectomy (Q4, 5%; vs Q1, 10%; P < .0001) or any concomitant procedure (Q4, 19%; vs Q1, 22%; P = .05). High-volume centers had had lower rates of pulmonary, renal, and overall complications (pulmonary: Q4, 7%; vs Q1-Q2, 8%-11%; renal: Q4, 16%; vs Q1-2, 19%-21%; P < .0001; overall mean number of complications: Q4, 0.46; vs Q1, 0.52; P = .0008). The crude 30-day and 1-year mortality rates were reduced at the higher volume centers (30 days: Q4, 3%; vs Q1-Q2, 6%; P < .0001; 1 year: Q4, 7%; vs Q1-Q2, 10%-11%; P < .0001). A strong inverse relationship between center volume and FTR was identified (P < .0001). In the adjusted analysis, OARs performed in high-volume centers (Q4 vs Q1) had a 50% risk reduction in FTR (odds ratio [OR], 0.48; 95% confidence interval [CI], 0.3-0.8; P = .004). Among the complications, a return to the operating room for bleeding was most likely to result in FTR (OR, 11.8; 95% CI, 4.3-33; P < .0001). A 24-fold increased risk of FTR was found for patients experiencing three or more complications vs one complication (OR, 24; 95% CI, 17-35; P < .0001). CONCLUSIONS: A greater center volume was strongly associated with significantly diminished FTR, reduced complications, and need for surgical adjuncts during OAR. These findings highlight the utility of center volume as an effective proxy to ensure high-quality aneurysm care.

A significant proportion of current endovascular aortic aneurysm repair practice fails to meet Society for Vascular Surgery clinical practice guideline recommended abdominal aortic aneurysm diameter treatment thresholds in the Vascular Quality Initiative.

BACKGROUND: There is mounting controversy surrounding the appropriate use of endovascular aortic aneurysm repair (EVAR) in contemporary practice. Persistent debate hinges on durability, cost, and survival. Accordingly, guidelines have attempted to clarify appropriate EVAR indications. The purpose of this analysis was to examine trends in EVAR practice throughout the United States and measure compliance with Society for Vascular Surgery (SVS) clinical practice diameter guidelines (CPGs). METHODS: We analyzed all elective repairs in the SVS Vascular Quality Initiative (VQI) EVAR registry from 2015 to 2019 (n = 25,112) and included patients with aneurysms confined to the infrarenal abdominal aorta. Center and surgeon variation with CPG diameter compliance was examined. Using a previously validated logistic regression model for risk adjustment, patients were stratified into predicted 1-year mortality risk tertiles and comparisons were made between patients meeting diameter guidelines (men ≥5.5;women ≥5.0 cm) and those who did not. RESULTS: Non-diameter-compliant EVAR occurred in 38.5% (n = 9675; diameter compliant, 61.5% [n = 15,437]). There was significant variation in CPG diameter compliance when stratified by VQI participating centers (range, 21%-95%; median, 61%; P < .001). This observation was amplified when categorized at the surgeon level (range, 0-100%; median, 63%; P < .0001). Notably, 82% of VQI surgeons (n = 852 of 1048) were non-diameter-compliant in more than 20% of their repairs. Moreover, among the 38.5% of patients failing to meet CPG diameter thresholds, 22.4% (n = 2171) were at high physiologic risk as determined by the validated SVS-VQI 1-year mortality calculator. Notably, the 1-year survival for the high-physiologic risk patients receiving non-guideline-compliant EVAR was worse compared with low- to intermediate-risk patients who were treated within recommended CPGs (92 ± 2% vs 97 ± 1%; log-rank P < .0001). CONCLUSIONS: A significant percentage of current US EVAR practice fails to adhere to the SVS diameter guidelines, as highlighted by the tremendous variation among VQI centers and surgeons. Furthermore, as noted by the 22% of patients undergoing noncompliant repair deemed to be at high physiologic risk, patient selection for EVAR seems to be suboptimal. Surprisingly, these findings are observed among the majority of VQI surgeons performing EVAR. In light of issues surrounding durability and cost, efforts to constrain observed deviation from recommended therapeutic size threshold guidelines would likely serve to improve abdominal aortic aneurysm care throughout the United States.

Non-guideline-compliant endovascular abdominal aortic aneurysm repair in women is associated with increased mortality and reintervention compared with men.

OBJECTIVE: Sex-based disparities in surgical outcomes have emerged as an important focus in contemporary healthcare delivery. Likewise, the appropriate usage of endovascular abdominal aortic aneurysm repair (EVAR) in the United States remains a subject of ongoing controversy, with a significant number of U.S. EVARs failing to adhere to the Society for Vascular Surgery (SVS) clinical practice guideline (CPG) diameter thresholds. The purpose of the present study was to determine the effect of sex among patients undergoing EVAR that was not compliant with the SVS CPGs. METHODS: All elective EVAR procedures for abdominal aortic aneurysms without a concomitant iliac aneurysm (≥3.0 cm) in the SVS Vascular Quality Initiative were analyzed (2015-2019; n = 25,112). SVS CPG noncompliant repairs were defined as a size of <5.5 cm for men and <5.0 cm for women. The primary endpoint was 30-day mortality. The secondary endpoints were all-cause mortality, complications, and reintervention. Logistic regression was performed to control for surgeon- and patient-level factors. Freedom from the endpoints was determined using the Kaplan-Meier method. RESULTS: Noncompliant EVAR was performed in 9675 patients (38.5%). Although men were significantly more likely to undergo such procedures (90% vs 10%; odds ratio [OR], 3.1; 95% confidence interval [CI], 2.9-3.4; P < .0001), the 30-day mortality was greater for the women than the men (1.8% vs 0.5%; P = .0003). Women also experienced significantly higher rates of multiple complications, including postoperative myocardial infarction (1% vs 0.3%; P = .006), respiratory failure (1.4% vs 0.6%; P = .01), intestinal ischemia (0.7% vs 0.2%; P = .003), access vessel hematoma (3% vs 1.2%; P = .0006), and iliac access vessel injury (2.4% vs 0.8%; P < .0001). Additionally, women experienced increased overall 1-year reintervention rates (11.5% vs 5.8%; P < .0001). In the adjusted analysis, 30-day mortality and any in-hospital complication risk remained significantly greater for the women (30-day death: OR, 3.1; 95% CI, 1.6-5.8; P = .0005; in-hospital complication: OR, 1.9; 95% CI, 1.4-2.6; P < .0001). Women also experienced increased reintervention rates over time compared with men (OR, 1.5; 95% CI, 1.1-2.2; P = .02). CONCLUSIONS: Although men were more likely to undergo non-CPG compliant EVAR, women experienced increased short-term morbidity and 30-day mortality and higher rates of reintervention when undergoing non-CPG compliant EVAR. These unanticipated findings necessitate increased scrutiny of current U.S. sex-based EVAR practice and should caution against the use of non-CPG compliant EVAR for women.

The financial evolution of endovascular aneurysm repair delivery in contemporary practice.

OBJECTIVE: The fiscal impact of endovascular repair (EVR) of aortic aneurysms and the requisite device costs have previously highlighted the tenuous long-term financial sustainability among Medicare beneficiaries. The Centers for Medicare & Medicaid Services have since reclassified EVR remuneration paradigms with new Medicare Severity Diagnosis-Related Groups (MS-DRGs) intended to better address the procedure's cost profile. The impact of this change remains unknown. The purpose of this analysis was to compare EVR-specific costs and revenue among Medicare beneficiaries both before and after this change. METHODS: All infrarenal EVRs performed in fiscal years (FYs) 2014 and 2015, before the MS-DRG change, and those performed in FYs 2017 and 2018, after the MS-DRG change, were identified using the DRG codes 238 (n = 108) and 269 (n = 84), respectively. We then identified those who were treated according to the instructions for use guidelines with a single manufacturer's device and billed to Medicare (n = 23 in FY14-15; n = 22 in FY17-18). From these cohorts, we determined total procedure technical costs, technical revenue, and net technical margin in conjunction with the hospital finance department. Results were then compared between these two groups. RESULTS: The two cohorts demonstrated similar demographic profiles (FY14-15 vs FY17-18 cohort: age, 78 years vs 74 years; median length of stay, 1.0 day vs 1.0 day). Mean total technical costs were slightly higher in the FY17-18 group ($24,511 in FY14-15 vs $26,445 in FY17-18). Graft implants continued to account for a significant portion of the total cost, with the device cost accounting for 56% of the total procedure costs in both cohorts. Net revenue was greater in the FY17-18 group by $5800 ($30,698 in FY14-15 vs $36,498 in FY17-18), resulting in an increased overall margin in the FY17-18 group compared with the FY14-15 group ($6188 in FY14-15 vs $10,053 in FY17-18). CONCLUSIONS: Device costs remain the single greatest cost driver associated with EVR delivery. DRG reclassification of EVR to address total procedure and implant costs appears to better address the requisite associated procedure costs and may thereby better support long-term fiscal sustainability of this procedure for hospitals and health systems alike.

Surgeon experience association with patient selection and outcomes after open abdominal aortic aneurysm repair.

BACKGROUND: Growing calls for guidelines advocating minimum annual case volumes for surgeon credentialing remain controversial. Although most attention to date has focused on the impact of obligatory case volume, less attention has been devoted to the more complex association between surgeon years of independent practice experience and procedure outcomes after open abdominal aortic aneurysm repair (OAR). Therefore, the purpose of this study was to explore the association of surgeon experience with case selection and real-world outcomes after OAR. METHODS: All Society for Vascular Surgery-Vascular Quality Initiative infrarenal and juxtarenal OARs (n = 11,900; 71% elective; 29% nonelective) from 2003 to 2019 were examined. Surgeon experience was defined by years in practice after training completion. Experience level at time of repair was categorized (≤5 years, n = 1048; 6-10 years, n = 1309; 11-15 years, n = 1244; and ≥16 years, n = 4772) and intergroup univariate comparisons were made. Logistic regression identified independent predictors of complications, 30-day death, and 1-year mortality. Models were constructed with or without surgeon experience strata to determine association with outcomes. RESULTS: Increasing surgeon experience was associated with performing greater proportions of elective procedures, whereas less experienced surgeons had disproportionate exposure to nonelective operations (elective, 73% ≥16 years vs 62% ≤5 years [P < .0001]; nonelective, ≤5 years, 38% vs 27%, ≥16-years [P < .0001]). Among surgeons who perform five or fewer cases per year, the risk of any aggregate major complication after elective OAR decreased significantly as experience increased (P = .0004), although no differences were detected in nonelective cases or among higher volume surgeons. Similarly, the risk of in-hospital death decreased with increasing experience (P = .004), but only among low-volume surgeons performing elective procedures. Comorbidities were similar across all experience strata for both elective and nonelective presentations; however, more experienced surgeons operated on higher proportions of nonelective patients with coronary disease (P = .04). Early career surgeons more frequently operated on patients with American Society of Anesthesiologists IV designation, larger abdominal aortic aneurysm diameters and used suprarenal/celiac cross-clamps more frequently than later career surgeons. The 1-year survival after elective and nonelective OAR was not impacted by surgeon experience (Ptrend > .15 for all comparisons). CONCLUSIONS: Increasing surgeon years of practice experience correlated significantly with a reduced risk of developing multiple postoperative complications, including postoperative death in the elective setting. Surgeons within their first 5 years of practice are exposed to greater proportions of nonelective cases but seem to have similar outcomes after these repairs compared with surgeons with more experience. Notably, surgeons in their first 5 years of practice operate on more complex elective patients as underscored by higher aggregate comorbidity scores, larger aneurysm diameters, and need for suprarenal aortic cross-clamping. These data have important implications on training paradigms, faculty recruitment, and the organization of mentorship when on boarding new surgeons.

Drain placement confers no benefit after carotid endarterectomy in the Vascular Quality Initiative.

OBJECTIVE: Whereas bleeding complications requiring a return to the operating room (OR) after carotid endarterectomy (CEA) are infrequent (1%), they are associated with an increased 30-day combined postoperative stroke or death rate. Drain placement after CEA varies among vascular surgeons, and there are limited data to support the practice. The goal of this study was to evaluate factors leading to drain placement and the effect of drains on postoperative outcomes including return to OR for bleeding, stroke, and death. METHODS: There were 47,752 patients identified undergoing CEA using the Vascular Quality Initiative registry from 2011 to 2015. Demographic, preoperative, and intraoperative factors between patients who underwent CEA with (n = 19,425) and without (n = 28,327) drain placement were compared. End points included return to the OR for bleeding, stroke, death, postoperative wound infection, and hospital length of stay. We then compared postoperative outcomes between groups using mixed effect logistic regression models to control for correlation within center. Similar methods were used to show relationship between return to OR for bleeding and other variables. Subgroup analysis of patients with drain placement was compared among centers with high (>66.7% of cases), medium (33.3%-66.7%), and low (<33.3%) use. RESULTS: Patients with drain placement were more likely to be taking a preoperative P2Y12 antagonist (P < .001), to have prior CEA or carotid artery stenting (P < .001), to use dextran (P < .001), and to have a concomitant procedure or coronary artery bypass graft (P < .001) and less likely to use protamine (P < .001) compared with those without drain placement. Drain placement did not prevent return to the OR for bleeding (P < .22). Re-exploration of the carotid artery after closure in the OR (P < .001), preoperative P2Y12 antagonist use (P < .001), and no protamine use (P < .001) were predictors for return to the OR for bleeding among those with drain placement. Of patients requiring return to the OR for bleeding, drain placement did not influence 30-day stroke (P = .82), 30-day mortality (P = .43), or 30-day combined stroke/mortality (P = .42) compared with those without drain placement. Drain placement did not influence postoperative wound infection (P < .3). Hospital length of stay was increased in patients with drain placement (P < .001). Return to the OR for bleeding (P = .24), wound infection (P = .16), and length of stay (P = .94) did not differ between the groups of high, medium, and low drain use. CONCLUSIONS: Drain placement after CEA does not reduce return to the OR for bleeding, nor does it reduce perioperative stroke or death. Drain placement is associated with increased length of stay.

Concomitant ipsilateral carotid endarterectomy and stenting is an effective treatment for tandem carotid artery lesions.

OBJECTIVE: Data regarding the treatment of tandem carotid artery lesions at the bifurcation and ipsilateral, proximal common carotid artery (CCA) are limited. It has been suggested that concomitant treatment with carotid endarterectomy (CEA) and proximal ipsilateral carotid artery stenting confers a high risk of stroke and death. The objective of this study was to evaluate the technique and outcomes of this hybrid procedure at a single institution. METHODS: A retrospective chart review was performed including patients who underwent CEA + ipsilateral carotid artery stenting for treatment of atherosclerotic carotid artery disease between December 2007 and April 2017. Primary endpoints were postoperative myocardial infarction, neurologic event, and perioperative mortality. RESULTS: Twenty-two patients (15 male [68%]) underwent CEA + ipsilateral carotid artery stenting with a mean follow-up of 67 ± 77 months. The mean age was 70.0 ± 6.1 years old, all with a prior smoking history (eight current smokers [64%]). Twelve patients (55%) were treated for symptomatic disease and three had a prior ipsilateral CEA (one also with CAS). Computed tomographic angiography imaging was performed preoperatively in 21 patients (95%). CEA was performed first in 18 patients (82%) followed by ipsilateral carotid artery stenting. CEA was performed with a patch in 20 and eversion endarterectomy in two patients. Ipsilateral CCA was stented in 21 patients (96%) and one innominate was stented in a patient with a right CEA. Additional endovascular interventions were performed in three patients: 1 innominate stent, 1 distal ipsilateral internal carotid artery stent, and 1 right subclavian artery stent. All proximal stents were placed with sheath access through the endarterectomy patch in 12 (55%), CCA in 7 (32%), and through the arteriotomy before patching in 3 (14%). Distal internal carotid artery clamping was performed in 18 (90%, available 20) of patients before ipsilateral carotid artery stenting. All proximal lesions were successfully treated endovascularly with no open conversion. One dissection was created and treated effectively with stenting. One perioperative stroke (4.5%) occurred in a patient treated for symptomatic disease, 1 postoperative myocardial infarction (4.5%), and 2 patients (9.1%) with cranial nerve injuries. There was one patient who expired within 30 days, shortly after discharge for unknown reasons. The mean length of stay was 2.6 ± 2.0 days. CONCLUSIONS: In appropriately selected patients, concomitant CEA and ipsilateral carotid artery stenting can be safely performed in high-risk patients with a low risk of myocardial infarction, neurologic events, and perioperative mortality when careful surgical technique is used, using direct carotid access, and distal carotid clamping for cerebral protection before stenting.

A comparison of reintervention rates after endovascular aneurysm repair between the Vascular Quality Initiative registry, Medicare claims, and chart review.

OBJECTIVE: The accurate measurement of reintervention after endovascular aneurysm repair (EVAR) is critical during postoperative surveillance. The purpose of this study was to compare reintervention rates after EVAR from three different data sources: the Vascular Quality Initiative (VQI) alone, VQI linked to Medicare claims (VQI-Medicare), and a "gold standard" of clinical chart review supplemented with telephone interviews. METHODS: We reviewed the medical records of 729 patients who underwent EVAR at our institution between 2003 and 2013. We excluded patients without follow-up reported to the VQI (n = 68 [9%]) or without Medicare claims information (n = 114 [16%]). All patients in the final analytic cohort (n = 547) had follow-up information available from all three data sources (VQI alone, VQI linked to Medicare, and chart review). We then compared reintervention rates between the three data sources. Our primary end points were the agreement between the three data sources and the Kaplan-Meier estimated rate of reintervention at 1 year, 2 years, and 3 years after EVAR. For gold standard assessment, we supplemented chart review with telephone interview as necessary to assess reintervention. RESULTS: VQI data alone identified 12 reintervention events in the first year after EVAR. Chart review confirmed all 12 events and identified 18 additional events not captured by the VQI. VQI-Medicare data successfully identified all 30 of these events within the first year. VQI-Medicare also documented four reinterventions in this time period that did not occur on the basis of patient interview (4/547 [0.7%]). The agreement between chart review and VQI-Medicare data at 1 year was excellent (κ = 0.93). At 3 years, there were 81 (18%) reinterventions detected by VQI-Medicare and 70 (16%) detected by chart review for a sensitivity of 92%, specificity of 96%, and κ of 0.80. Kaplan-Meier survival analysis demonstrated similar reintervention rates after 3 years between VQI-Medicare and chart review (log-rank, P = .59). CONCLUSIONS: Chart review after EVAR demonstrated a 6% 1-year and 16% 3-year reintervention rate, and almost all (92%) of these events were accurately captured using VQI-Medicare data. Linking VQI data with Medicare claims allows an accurate assessment of reintervention rates after EVAR without labor-intensive physician chart review.

Active smoking in claudicants undergoing lower extremity bypass predicts decreased graft patency and worse overall survival.

OBJECTIVE: Performing lower extremity bypass (LEB) in actively smoking claudicants remains controversial. Whereas some surgeons advocate a strict nonoperative approach to active smokers, citing perceived inferior outcomes, others will proceed with surgical bypass if the patient is anatomically suited and medical management has failed. The purpose of this study was to determine the impact of active smoking on LEB outcomes among claudicants. METHODS: All patients undergoing infrainguinal LEB for claudication in the Vascular Study Group of New England from 2003 to 2016 were analyzed. Smoking was defined as active tobacco use within 1 month of surgery. End points included in-hospital outcomes; long-term primary, assisted primary, and secondary patency; and mortality. Univariate, Cox multivariable, and Kaplan-Meier methods were used to determine the impact of smoking. Propensity score matching was performed to control for intergroup differences. RESULTS: Of 1789 LEBs, 971 (54%) were performed in nonsmokers and 818 (46%) in smokers. The follow-up rate was 87% at a mean of 382 days (standard error, ±6.8 days). Smokers were younger (60 vs 68 years; P < .001) and were less likely to have multiple comorbidities, including hypertension, coronary artery disease, congestive heart failure, diabetes, and chronic renal insufficiency (P ≤ .05); they were more likely to have an above-knee popliteal bypass target (52% vs 43%; P = .001). Smokers also had lower rates of postoperative major cardiac events (2.4% vs 5.3%; P = .002) and perioperative blood transfusion (5.6% vs 11%; P < .001) compared with nonsmokers, but there was no difference in respiratory complications, wound complications, or mortality. At 2-year follow-up, smokers demonstrated inferior primary patency (48% vs 61%; P = .03) and assisted primary patency (59% vs 74%; P = .01), with comparable rates of secondary patency and overall mortality. Propensity matching yielded two similar groups (n = 450 for each). Propensity-matched smokers had significantly decreased 2-year primary patency (43% vs 58%; P = .02), assisted primary patency (54% vs 71%; P = .03), and 10-year survival (69% vs 76%; P < .01). Cox multivariable analysis confirmed that smoking was an independent predictor of diminished primary patency (hazard ratio [HR], 1.3; 95% confidence interval [CI], 1.0-1.6; P = .03), assisted primary patency (HR, 1.4; 95% CI, 1.1-1.8; P = .004), and overall survival (HR, 1.3; 95% CI, 1.1-1.5; P < .001). CONCLUSIONS: Despite the fact that smokers are younger and have fewer comorbidities than nonsmokers, active smoking at the time of LEB for claudication is associated with decreased long-term patency and decreased overall survival. Surgeons should consider smoking an important risk factor for worse LEB outcomes in smokers compared with nonsmokers.

Novel Application of Branched Endograft for Preservation of Pelvic Circulation.

BACKGROUND: Endovascular repair of a proximal anastomotic pseudoaneurysm (APSA) of an end-to-side aortobifemoral bypass (ABF) can lead to pelvic ischemia. We present a novel application of branched aortic endograft to repair such pseudoaneurysm while preserving flow into the ABF and native aortoiliac system. METHODS: A 71-year-old male with history of aortoiliac occlusive disease resulting in lifestyle limiting claudication was treated with an aortobifemoral bypass in 1999. The patient developed an 8.8 cm pseudoaneurysm at the aortic anastomosis. CTA demonstrated patent right common and internal iliac arteries with an occluded right external iliac artery and occluded left common and external iliac arteries. RESULTS: A 24 × 80 mm endograft with an 8 × 15 mm posterior branch based on the Cook Zenith device (Bloomington, IN) was delivered via a right femoral artery exposure. The preloaded wire of the main body was snared via left brachial access. A 10F sheath was advanced into the side branch of the graft to deliver a 10 × 10-mm Bard Fluency (Covington, Georgia) stent graft into the right common iliac artery. The branch was reinforced proximally with an 8 × 17 mm Boston Scientific Express (Marlborough, MA) stent. The patient was discharged after 5 days. At 1 month, CTA demonstrated patent ABF, patent branch graft into the pelvis, and exclusion of the pseudoaneurysm. CONCLUSIONS: Branch grafts can provide minimally invasive revision of a failing ABF, in this case an APSA, while preserving pelvic circulation and lower extremity perfusion.

Clinical and anatomic outcomes after carotid endarterectomy.

OBJECTIVE: The purpose of this study was to examine 30-day and long-term outcomes after carotid endarterectomy (CEA) in a contemporary series and to identify variables associated with stroke and death after CEA. METHODS: This was a retrospective review of patients undergoing an isolated CEA at a single institution between January 1989 and December 2005. Primary study end points were 30-day and long-term overall stroke, ipsilateral stroke, and death. Secondary end points were recurrent stenosis (>70% stenosis) and reintervention. Kaplan-Meier analysis was used to create survival curves for the long-term study end points. Multivariate models were created to identify variables associated with the study end points. RESULTS: During the study period, 3014 CEAs were performed on 2644 patients (mean age, 71.0 ± 8.9 years; 60.9% male; 33.5% symptomatic; 37% primary closure), with mean follow-up of 7.0 years. The 30-day ipsilateral stroke, death, and combined ipsilateral stroke/death rates were 1.3%, 1.1%, and 2.2%, respectively. Previous ipsilateral CEA or neck dissection for cancer (hazard ratio [HR], 3.68; P = .0081) and symptomatic disease (HR, 2.45; P = .0071) were predictive of 30-day ipsilateral stroke. Stroke-free survival was 93.8% at 4 years and 86.9% at 10 years. Diabetes (HR, 1.94; P < .0001), symptomatic disease (HR, 1.75; P < .0001), female gender (HR, 1.34; P = .035), and increasing age (HR, 1.02; P < .0001) were predictors of long-term overall stroke. Ipsilateral stroke-free survival was 97.6% at 5 years and 94.6% at 10 years, respectively. Contralateral occlusion (HR, 2.06; P = .025) and symptomatic disease (HR, 1.87; P = .003) were predictors of ipsilateral stroke, whereas antilipid therapy was protective (HR, 0.65; P = .049). Overall survival was 70.1% at 5 years and 42.2% at 10 years, with no difference between symptomatic and asymptomatic patients. Although a variety of comorbidities were associated with inferior late survival, as anticipated, female gender (HR, 0.89; P = .016) and lipid-lowering therapy (HR, 0.69; P < .0001) were protective. Reintervention was 3.4% at 5 years and 6.6% at 10 years, with primary closure (vs patch angioplasty/eversion) increasing the risk of reintervention (HR, 1.72; P = .007). CONCLUSIONS: CEA has favorable perioperative and long-term clinical and anatomic outcomes with respect to its goal of stroke prevention for symptomatic and asymptomatic patients. Adjuvant medical therapy (antilipid) has increased overall and ipsilateral stroke-free survival.

Renal artery duplex ultrasound criteria for the detection of significant in-stent restenosis.

OBJECTIVES: To define velocity criteria by ultrasonography for the detection of hemodynamically significant (>60%) renal artery in-stent restenosis (ISR). BACKGROUND: The restenosis rate after renal artery stenting ranges between 10% and 20%. While duplex ultrasound criteria have been validated for native renal artery stenosis, there are no uniformly accepted validated criteria for stented renal arteries. METHODS: Vascular laboratory databases from two academic medical centers were retrospectively reviewed for patients who underwent renal artery stenting followed by duplex ultrasound evaluation and angiography (CT angiography or catheter angiography) as the gold standard. RESULTS: A cohort of 132 stented renal arteries that had angiographic comparisons was analyzed. Eighty-eight renal arteries demonstrated 0-59% stenosis while 44 renal arteries revealed 60-99% stenosis by angiography. Both the mean peak systolic velocity (PSV) and the renal artery-to-aortic ratio (RAR) were significantly higher in renal arteries with 60-99% restenosis compared with those with 0-59% restenosis (PSV: 382 cm/sec ± 128 vs. 129 cm/sec ± 62, P<0.001; RAR: 5.3 ± 2.4 vs. 2.1 ± 1.0, P <0.001). The optimal PSV and RAR cutoffs for detecting 60-99% ISR were calculated by receiver operator characteristics curve analysis. The velocity criteria that are associated with these results will be discussed. CONCLUSION: Duplex ultrasonography is an accurate technique to identify significant restenosis in stented renal arteries. The PSV and RAR cutoffs for detecting renal artery ISR are higher than those in native, unstented renal arteries. A normal duplex ultrasound after renal artery stenting virtually excludes significant restenosis.

A risk prediction model for determining appropriateness of CEA in patients with asymptomatic carotid artery stenosis.

OBJECTIVE: The benefit of carotid endarterectomy (CEA) over medical therapy in patients with asymptomatic carotid artery stenosis is predicated upon a life expectancy of at least 5 years after the procedure. The goal of this study was to create a scoring system for prediction of 5-year survival after CEA that can be used to triage patients with ACAS. METHODS: All patients who underwent CEA for severe asymptomatic carotid stenosis from 1989 to 2005 were identified. Long-term survival was determined by a review of hospital records and the social security death index. Because all patients had at least 5-year follow-up, a logistic regression of predictors of survival at 5 years was performed and the odds ratios associated with particular significant comorbidities were used to create a scoring system to predict survival. The scoring system was then validated within the cohort using the Hosmer-Lemeshow Test and a derivation/validation receiver operating characteristic (ROC) curve. RESULTS: There were 2004 CEA performed in 1791 patients. The average follow-up was 130 ± 49 months. The clinical profile of the cohort data included 84% hypertension, 56% coronary artery disease (CAD), 24% diabetes, and 71% on statins. The 30-day stroke rate was 1.1% and the death rate was 0.7%. The actual 5-year survival was 73%. Logistic regression yielded the following predictors of mortality: age (by decade) (odds ratio [OR] = 1.8, P < 0.0001), CAD (OR = 1.5, P = 0.0007), chronic obstructive pulmonary disease (OR = 2.5; P < 0.0001), diabetes (OR = 1.7, P < 0.0001), neck radiation (OR = 2.6, P = 0.005), no statin (OR = 2.1, P < 0.0001), and creatinine more than 1.5 (OR = 2.6, P < 0.0001). These variables were then assigned a hierarchal point scoring system in accordance with the OR value. The 5-year survival based on the scoring system was as follows: 0 to 5 points = 92.5%, 6 to 8 points = 83.6%, 9 to 11 points = 63.7%, 12 to 14 points = 46.5%, and more than 15 points = 33.8%. The Hosmer-Lemeshow test validated the scoring system (P = 0.26) and there was no difference in the ROC curves (C statistic = 0.74 vs 0.73). CONCLUSIONS: This validated scoring system can be a useful tool for determining which patients are likely to benefit most from CEA based on the probability of long-term survival. Given that the 5-year survival of patients in the medical arm of the asymptomatic CEA trials was 60% to 70%, it is reasonable to conclude that patients who score 0 to 8 points are excellent candidates for CEA whereas most patients with ≥12 points should be managed with medical therapy alone.

Inhalation of carbon monoxide reduces skeletal muscle injury after hind limb ischemia-reperfusion injury in mice.

BACKGROUND: The purpose of this study was to determine if inhaled carbon monoxide (CO) can ameliorate skeletal muscle injury, modulate endogenous heme oxygenase-1 expression, and improve indexes of tissue integrity and inflammation after hind limb ischemia reperfusion. METHODS: C57BL6 mice inhaling CO (250 ppm) or room air were subjected to 1.5 hours of ischemia followed by limb reperfusion for either 3 or 6 hours (total treatment time, 4.5 or 7.5 h). After the initial period of reperfusion, all mice breathed only room air until 24 hours after the onset of ischemia. Mice were killed at either the end of CO treatment or at 24 hours' reperfusion. Skeletal muscle was subjected to histologic and biochemical analysis. RESULTS: CO treatment for 7.5 hours protected skeletal muscle from histologic and structural evidence of skeletal muscle injury. Serum and tissue cytokines were reduced significantly (P < .05) in mice treated with CO for 7.5 hours. Tubulin, heme oxygenase, and adenosine triphosphate levels were higher in CO-treated mice. CONCLUSIONS: Inhaled CO protected muscle from structural injury and energy depletion after ischemia reperfusion.

The effects of systemic hypothermia on a murine model of thoracic aortic ischemia reperfusion.

INTRODUCTION: Hypothermia is widely used to mediate ischemia-reperfusion injury associated with repair of the thoracoabdominal aorta. Experiments were designed in a murine model of thoracic aortic ischemia-reperfusion (TAR) to evaluate the effect of moderate systemic hypothermia on neurologic function, spinal cord morphology, and indices of inflammation in critical organs. METHODS: C57BL/6 mice were subjected to TAR under hypothermic (34 degrees C) or normothermic (38 degrees C) conditions, followed by 24 or 48 hours of normothermic reperfusion. Neurologic functions were assessed during reperfusion. Spinal cords were examined at 24 and 48 hours after reperfusion, and the degree of injury qualified by counting the number of viable motor neurons within the anterior horns. Keratinocyte chemokine, interleukin-6, and myeloperoxidase levels were measured from lung, liver, and kidney at 24 and 48 hours. RESULTS: Normothermic TAR resulted in a dense neurologic deficit in all mice throughout the reperfusion period. Mice subjected to TAR under hypothermic conditions had transient, mild neurologic deficit during the initial periods of reperfusion. Between 24 and 48 hours, delayed paralysis developed in half of these mice, whereas the other half remained neurologically intact. Spinal cord histology showed a graded degree of injury that correlated with neurologic function. There was no correlation between markers of inflammation in various organs and neurologic outcomes following TAR. CONCLUSION: Systemic moderate hypothermia was protective against immediate paralysis after TAR in all cases and was associated with delayed paralysis in 50% of mice. This study suggests that delayed-onset paralysis may be the result of a local insult, rather than a systemic inflammatory event, precipitating spinal cord injury.

Infrapopliteal balloon angioplasty for the treatment of chronic occlusive disease.

OBJECTIVE: There is little documentation of the effectiveness of percutaneous balloon angioplasty (PTA) of infrapopliteal vessels for the treatment of chronic lower extremity ischemia. This study reviewed our recent experience with infrapopliteal PTA in a large series of patients to determine its effectiveness as a treatment modality. METHODS: All patients undergoing primary infrapopliteal PTA from March 2002 to June 2006 were included. Primary study end points were primary patency, assisted patency, limb salvage, and patient survival assessed by Kaplan-Meier life-table analysis. Factors predictive of PTA failure and patient longevity were evaluated by multivariate methods. RESULTS: There were 155 PTAs undertaken in 144 patients (70% men; mean age, 74 years), with critical limb ischemia (86%), diabetes (66%), and renal insufficiency (45%). Infrapopliteal lesions were classified as TransAtlantic Inter-Society Consensus A (7%), B (18%), C (39%), and D (35%). PTA was confined to the infrapopliteal segment in 40 (26%), and 115 (74%) underwent multilevel treatment. Five patients (3%) received stents. Technical success was 95%. The 30-day mortality was 2%, and major morbidity was 3%. The mean follow-up was 22 months (range, 0-54 months). The 40-month actuarial primary patency was 62% (standard error, 5%), with assisted patency (infrapopliteal re-PTA, 25 [16%]) of 90%. Interval conversion to bypass surgery occurred in seven (5%). Nonhealing ulcers occurred in 118 patients (76%), of which 76 (64%) healed during follow-up. Of the 42 unhealed ulcers, 15 (13%) required major amputations for a 40-month limb salvage of 86.2%. Multivariate predictors that were negative for primary patency included 0/1 vessel runoff (P = .01), critical limb ischemia (P = .002), and dialysis (P = .03). Negative predictors of limb salvage included dialysis (P = .007) and failure to improve runoff to the foot (P = .006). At 40-months, patient survival was 54%, with negative predictors including severe pulmonary disease (P = .01), coronary artery disease (P = .04), and renal insufficiency (P < .001). CONCLUSIONS: Infrapopliteal angioplasty can be performed safely with favorable results in patients with limited longevity. Primary patency is related to disease extent. Secondary interventions may be necessary to maintain clinical success. These data indicate that PTA should be considered as initial therapy for infrapopliteal occlusive disease in patients with lower extremity ischemia.

Outcomes after carotid endarterectomy: is there a high-risk population? A National Surgical Quality Improvement Program report.

OBJECTIVE: Carotid endarterectomy (CEA) is the standard treatment of carotid stenosis for symptomatic and asymptomatic patients. Carotid angioplasty and stenting (CAS), however, has been proposed as alternative therapy for patients deemed at high-risk for CEA. This study examined 30-day adjudicated outcomes in a contemporary series of CEAs and assessed the validity of criteria used to define a potential high-risk patient population for CEA. METHODS: Patients undergoing isolated CEA in private sector hospitals between Jan 1, 2005, and Dec 31, 2006, were identified using the prospectively gathered National Surgical Quality Improvement Program database. The primary study end points were 30-day stroke and death rates. Demographic, preoperative, and intraoperative variables were examined using multivariate models to identify variables associated with the study end points. Variables used to define systemic "high-risk" patients in the Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) study (active cardiac disease, severe chronic obstructive pulmonary disease, and octogenarian status) were examined individually and in composite fashion for association with study endpoints. RESULTS: Of the 3949 CEAs performed, 59% were in men, 30% were "high-risk" (19% age >80), and 43% had a previous neurologic event. The 30-day stroke rate was 1.6%, the death rate was 0.7%, and combined stroke/death rate was 2.2%. Multivariate analysis showed that intraoperative transfusion (odds ratio [OR], 5.95; 95% confidence interval [CI], 1.71-20.66; P = .005), prior major stroke (OR, 5.34; 95% CI, 2.96-9.64; P < .0001), shorter height (surrogate for small artery size; OR, 1.09; 95% CI, 1.02-1.16; P = .010), and increased anesthesia time (OR, 1.02; 95% CI, 1.00-1.03; P = .008) were predictive of stroke. Critical limb ischemia (OR, 12.72; 95% CI, 3.49-46.40; P < .0001) and poor functional status (OR, 7.05; 95% CI, 2.95-16.82; P < .0001) were independent correlates of death. Systemic high-risk variables, either combined or individually, did not increase risk of stroke or death on multivariate analysis. CONCLUSION: CEA is associated with favorable 30-day outcomes across a spectrum of patient comorbidity features including octogenarian status. Anatomic and technical features are the important predictors of perioperative stroke, whereas critical limb ischemia and poor functional status are important predictors of death for patients undergoing CEA. These data refute the concept that CAS is preferred for patients deemed high-risk by virtue of systemic comorbidities.