Predictors of Arteriovenous Fistula Maturation among Patients with Severe Obesity.

BACKGROUND: There is an increasing prevalence of obesity among patients who develop end-stage renal disease and require dialysis. While referrals for arteriovenous fistulas (AVFs) among patients with class 2-3 obesity (i.e., body mass index [BMI] ≥ 35) are increasing, it is unclear what type of autogenous access is most likely to mature in this patient population. This study was designed to evaluate factors that impact maturation of AVF among patients with class ≥2 obesity. METHODS: We retrospectively reviewed AVFs created at a single center from 2016 to 2019 for patients who had undergone dialysis within the same healthcare system. Ultrasound studies were used to evaluate factors that defined functional maturation, including diameter, depth, and volume flow rates through the fistula. Logistic regression models were used to evaluate the risk-adjusted association between class ≥2 obesity and functional maturation. RESULTS: A total of 202 AVFs [radiocephalic (24%), brachiocephalic (43%), and transposed brachiobasilic (33%)] were created during the study period, of which 53 (26%) patients had a BMI >35. Functional maturation was significantly lower among patients with class ≥2 obesity undergoing brachiocephalic (58% obese versus 82% normal-overweight; P = 0.017), but not radiocephalic or brachiobasilic AVFs. This was primarily a result of excessive AVF depth in severely obese patients (9.6 ± 4.0 mm obese versus 6.0 ± 2.7 mm normal-overweight; P < 0.001), whereas there was no significant difference found in average volume flow or AVF diameter between groups. In risk-adjusted models, a BMI ≥35 was associated with a significantly lower likelihood of achieving AVF functional maturation (odds ratio: 0.38; 95% confidence interval: 0.18-0.78; P = 0.009) after controlling for age, sex, socioeconomic status, and fistula type. CONCLUSIONS: Patients with a BMI >35 are less likely to mature AVFs after creation. This principally affects brachiocephalic AVFs and occurs because of increased fistula depth as opposed to diameter or volume flow parameters. These data can help guide decision-making when planning AVF placement in severely obese patients.

High-intensity statin therapy reduces risk of amputation and reintervention among patients undergoing lower extremity bypass for chronic limb-threatening ischemia.

OBJECTIVE: Statins are considered standard-of-care medical therapy for patients undergoing lower extremity bypass (LEB) procedures for chronic limb-threatening ischemia (CLTI). It is unclear, however, whether up-titrating and maintaining patients on higher-intensity statin medications following LEB improves limb salvage outcomes. This study was designed to evaluate whether high-intensity statin therapy impacts the risk of amputation and reintervention following LEB for patients with CLTI. METHODS: The IBM MarketScan database was used to identify adult patients (18-99 years old) who underwent a LEB for CLTI between 2008 and 2017. Patients lacking insurance covering drug reimbursement or those who already had undergone amputation before time of bypass were excluded. Using pharmacy claims and national drug codes to define statin intensity, patients were stratified into three groups: high-intensity, low-intensity, and limited statin therapy. The association between intensity of statin therapy and need for reintervention and/or major amputation after LEB was analyzed using Kaplan-Meier curves and risk-adjusted Cox proportional hazard models. RESULTS: A total of 25,907 patients who underwent LEB for CLTI were identified, of which 6696 (26%) were maintained on high-dose statins, 9297 (36%) were on low-dose statins, and 9914 (38%) had inconsistent pharmacy claims for statin therapy after surgery. Patients on high-intensity statins were, on average, younger and more likely to be male with comorbid disease (diabetes, hypertension, hyperlipidemia, obesity, renal insufficiency, ischemic heart disease, cerebrovascular disease, and tobacco abuse) than patients on low-intensity statins or limited statin therapy (P < .001 for all comparisons). Following LEB, 6649 patients (25.6%) required a reintervention, and 2550 patients (9.8%) went on to have a major amputation during follow-up. Patients maintained on high-intensity statins after LEB had a significantly lower likelihood of requiring a reintervention (hazard ratio [HR], 0.48; 95% confidence interval [CI], 0.45-0.51; P < .001) or amputation (HR, 0.27; 95% CI, 0.24-0.30; P < .001) as compared with patients on limited statin therapy. Further, there was a dose-dependent effect for these outcomes relative to patients on low-intensity statins in risk-adjusted models, and it was independent of whether an autologous vein graft was used for the LEB. Finally, among patients who underwent a reintervention, high-dose statin therapy also significantly reduced the HR for subsequent amputation (HR, 0.21; 95% CI, 0.18-0.25; P < .001). CONCLUSIONS: Patients with CLTI on high-intensity therapy following LEB had a significantly lower risk of requiring subsequent reintervention and amputation when compared with patients on low-intensity statins or with limited statin use. These data suggest that patients with CLTI should be up-titrated and/or maintained on high-intensity statins following revascularization whenever possible.

Rules of 6 criteria predict dialysis fistula maturation but not all rules are equal.

OBJECTIVE: The Rules of 6 (flow volume >600 mL/min, vein diameter >6 mm, vein depth <6 mm) are widely used to determine when an arteriovenous fistula (AVF) will support dialysis. Thus, we tested the utility of the Rules of 6 in clinical practice. METHODS: We retrospectively reviewed AVFs created at a single center from 2016 to 2019 for patients who had undergone dialysis within the same healthcare system. Clinical records and postoperative ultrasound studies were reviewed for the Rules of 6 criteria. Maturation was defined as use of the AVF with two needles for 75% of the dialysis sessions for a continuous 4-week period, with a mean flow of 300 mL/min or urea clearance (Kt/V) of 1.2. Predictors of maturation were assessed using logistic regression and receiver operating characteristic (ROC) curves. RESULTS: Five surgeons performed 202 AVFs of three types during 2016 to 2019 (radial-cephalic, n = 49; brachial-cephalic, n = 87; brachial-basilic, n = 66). Maturation occurred in 150 AVFs (74%; primary, n = 101 [50%]; assisted, n = 49 [24%]), while 52 (26%) failed to mature. Maturation did not vary by AVF type or patient sex or diabetes status. A higher body mass index was associated with failure to mature (P = .004). Only 16 mature AVFs (11%) met all three Rules of 6 using mean values for flow, diameter, and depth. However, 101 (67%) met all three Rules using the extreme, maximum or minimum, values. On multivariate analysis, each Rule of 6 was independently associated with maturation. If all three Rules were met, the AVF was nearly 10-fold more likely to have matured compared with an AVF satisfying no Rule. The body mass index correlated strongly with the vein depth (P < .001); however, both characteristics independently predicted maturation. The chance of maturation was highest if flow and depth Rules were met (positive predictive value [PPV], 93%); if all three rules were met, the PPV was 92%. The ROC area under curve (AUC) values for meeting flow volume and vein depth Rules together were higher than if all three Rules had been satisfied (0.784 vs 0.754). The PPV for diameter alone (78%) was the lowest of all PPVs for the three Rules and the ROC-AUC was only 0.588. If all three Rules together were not satisfied using extreme values, the negative predictive value was only 47%. CONCLUSIONS: The Rules of 6 predict AVF maturation, especially when using extreme, maximum or minimum, values to satisfy each Rule. Flow volume and vein depth together predict maturation equally as well as meeting all three Rules. Vein diameter seems less important. The Rules of 6 might be too stringent if used exclusively to predict for functional AVF maturation.

Vascular surgery triage during the coronavirus disease 2019 pandemic.

OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic has resulted in a marked increase in hospital usage, medical resource scarcity, and rationing of surgical procedures. This has created the need for strategies to triage surgical patients. We have described our experience using the American College of Surgeons (ACS) COVID-19 guidelines for triage of vascular surgery patients in an academic surgery practice. METHODS: We used the ACS guidelines as a framework to direct the triage of vascular surgery patients during the COVID-19 pandemic. We retrospectively analyzed the results of this triage during the first month of surgical restriction at our hospital. Patients undergoing surgery were identified by reviewing the operating room schedule. We reviewed the electronic medical records (EMRs) and assigned an ACS category, condition, and tier class to each completed surgery. Surgeries that were postponed during the same period were identified from a prospectively maintained list. We reviewed the EMRs for all postponed surgeries and assigned an ACS category, condition, and tier class to each surgery. We reviewed the EMRs for all postponed procedures to identify any adverse events related to the treatment delay. RESULTS: We performed 69 surgeries in 52 patients during the study period. All surgeries were performed to treat emergent, urgent, or time-sensitive elective diagnoses. Of the 69 surgeries, 47 (68%) were from tier 3 and 22 (32%) from tier 2b. We did not perform any surgeries from tier 1 or 2a. We postponed surgery for 66 patients during the same period, of which 36 (55%) were from tier 1, 22 (33%) from tier 2a, 5 (8%) from tier 2b, and 3 (5%) could not be assigned a tier class. No tier 3 surgeries were postponed. Of the 66 patients, 3 (4.5%) experienced an adverse event that could be attributed to the treatment delay. CONCLUSIONS: The ACS triage guidelines provided an effective method to decrease vascular surgical volumes during the COVID-19 pandemic without an increase in patient morbidity. We believe the clinical utility of the guidelines would be strengthened by incorporating the SURGCON/VASCCON (surgical activity condition/vascular activity condition) threat level alert system.

Long-Term Impact of Vascular Surgery Stress on Frail Older Patients.

BACKGROUND: Frailty is a syndrome where the ability to cope with acute physiological stress is compromised, although it is unclear what impact this stress has on long-term outcomes. Vascular-Physiological and Operative Severity Score for enumeration of Mortality and Morbidity is a validated method for calculating levels of stress associated with vascular procedures. We designed this study to evaluate the long-term impact of different levels of surgical stress among frail older patients undergoing vascular surgery procedures. METHODS: We identified all independently living patients who underwent prospective frailty assessment followed by an elective vascular surgery procedure captured in the Vascular Quality Initiative registry (endovascular abdominal aortic aneurysm [AAA] repair, thoracic endovascular aortic repair, suprainguinal and infrainguinal bypass, peripheral vascular intervention, carotid endarterectomy, and open AAA) at an academic institution between January 2016 and July 2018. Patient- and procedure-level data were obtained from our institutional data warehouse and Vascular Quality Initiative database, and used to calculate Vascular-Physiological and Operative Severity Score for enumeration of Mortality and Morbidity scores. The association between frailty and composite outcome of any major complications (surgical site infection; graft thrombectomy; major amputation; adverse cardiac, pulmonary, or neurologic event; acute renal insufficiency; and/or reoperation related to the index procedure), nonhome living status, or death within 1 year after low-, medium-, and high-stress vascular procedures was evaluated using bivariate and logistic regression models. RESULTS: A total of 163 patients were identified (70% male, mean age 67.8 years) who underwent open AAA repair (6%), endovascular AAA repair (21%), thoracic endovascular aortic repair (7%), suprainguinal bypass (5%), infrainguinal bypass (18%), carotid endarterectomy (18%), or peripheral vascular interventions (25%), which included 44 (27%) patients diagnosed with frailty before surgery. Overall, frail patients had significantly higher rates of the 1-year composite outcome (48% frail versus 27% nonfrail; P = 0.012) when compared with nonfrail patients, with a significant dose-dependent effect as the level of stress increased. In comparison, increasing levels of surgical stress had a negligible effect on long-term outcomes among nonfrail patients. The interaction between frailty and high surgical stress was found in adjusted regression models to be a significant predictor of adverse outcomes within 1 year after vascular surgery (odds ratio, 3.3; 95% confidence interval, 1.3-8.6; P < 0.01). CONCLUSIONS: Frail patients who undergo high-stress vascular procedures have a significantly higher rate of complications leading to loss of functional independence and mortality within the year after their surgery. These data suggest that estimates of surgical stress should be incorporated into clinical decision making for frail older patients before and after surgery.

Prognostic implications of diagnosing frailty and sarcopenia in vascular surgery practice.

OBJECTIVE: Frailty and sarcopenia are related but independent conditions commonly diagnosed in older patients that can be used to assess their ability to tolerate the stress of major vascular surgery. For surgical decision-making, however, it is important to know the prognostic implications associated with each of these conditions. The study was designed to assess the association of frailty and sarcopenia phenotypes with long-term survival of patients undergoing surgical and nonsurgical management of vascular disease. METHODS: We retrospectively reviewed all patients presenting to the vascular surgery clinic at an academic hospital between December 2015 and August 2017 who underwent prospective frailty assessment with the Clinical Frailty Scale and who had abdominal computed tomography (CT) scans performed within the preceding 12 months. A single axial CT image at the caudal end of the third lumbar vertebra was assessed to measure cross-sectional areas of skeletal muscle. Sarcopenia was defined by established criteria specific for male and female patients. After patients were stratified by frailty and sarcopenia diagnoses along with comorbidities, the association with all-cause mortality was analyzed by Kaplan-Meier curves and Cox regression models. RESULTS: A total of 415 patients underwent both frailty and sarcopenia assessment, of whom 112 (27%) met sarcopenia criteria alone, 48 (12%) met only frailty criteria, and 56 (13%) met criteria for both phenotypes. There were 199 (48%) controls who met neither criterion. Vascular operations were performed in 167 (40%) patients after frailty and sarcopenia assessment, whereas 248 (60%) patients were managed nonoperatively with median (interquartile range) follow-up after CT imaging of 1.5 (1.1-2.2) years. Patients diagnosed with either phenotype were older (mean, 65 years vs 59 years; P < .001) and more likely to be male (69% vs 54%; P < .001) compared with patients without sarcopenia or frailty. Long-term survival was significantly decreased for patients diagnosed with either frailty alone or frailty and sarcopenia who underwent surgical or nonsurgical management (log-rank, P < .001 for both comparisons). In multivariate regression models, however, frailty was the only independent variable (hazard ratio, 7.7; 95% confidence interval, 3.2-18.7; P < .001) that predicted mortality. CONCLUSIONS: Frailty and sarcopenia overlap to varying degrees in patients presenting to vascular surgery clinics and can be used alone or in combination to predict long-term survival of older patients. However, our data indicate that it was only the diagnosis of frailty that was an independent predictor of mortality and had the strongest prognostic significance in patients undergoing both surgical and nonoperative management.

Repair of a symptomatic true radial artery aneurysm at the anatomic snuff box with interposition great saphenous vein graft.

Radial artery aneurysms are exceedingly rare, with only a few reported cases of surgical revascularization. We describe a 25-year-old man who presented with severe ischemia of the right hand secondary to an idiopathic true radial artery aneurysm at the anatomic snuff box. The patient had embolic occlusions in his hand and fingers that were treated with catheter-directed thrombolysis. During angiography, the blood supply to the affected hand was determined to be radial artery dominant, and therefore the aneurysm was resected and revascularized using an interposition great saphenous vein graft. The patient denied ischemic symptoms postoperatively, and duplex ultrasound examination at a 10-month follow-up showed patent interposition graft.

Preoperative frailty assessment predicts loss of independence after vascular surgery.

OBJECTIVE: Frailty, a clinical syndrome associated with loss of metabolic reserves, is prevalent among patients who present to vascular surgery clinics for evaluation. The Clinical Frailty Scale (CFS) is a rapid assessment method shown to be highly specific for identifying frail patients. In this study, we sought to evaluate whether the preoperative CFS score could be used to predict loss of independence after major vascular procedures. METHODS: We identified all patients living independently at home who were prospectively assessed using the CFS before undergoing an elective major vascular surgery procedure (admitted for >24 hours) at an academic medical center between December 2015 and December 2017. Patient- and procedure-level clinical data were obtained from our institutional Vascular Quality Initiative registry database. The composite outcome of discharge to a nonhome location or 30-day mortality was evaluated using bivariate and multivariate regression models. RESULTS: A total of 134 independent patients were assessed using the CFS before they underwent elective open abdominal aortic aneurysm repair (8%), endovascular aneurysm repair (26%), thoracic endovascular aortic repair (6%), suprainguinal bypass (6%), infrainguinal bypass (16%), carotid endarterectomy (19%), or peripheral vascular intervention (20%). Among 39 (29%) individuals categorized as being frail using the CFS, there was no significant difference in age or American Society of Anesthesiologists physical status compared with nonfrail patients. However, frail patients were significantly more likely to need mobility assistance after surgery (62% frail vs 22% nonfrail; P < .01) and to be discharged to a nonhome location (22% frail vs 6% nonfrail; P = .01) or to die within 30 days after surgery (8% frail vs 0% nonfrail; P < .01). Preoperative frailty was associated with a >12-fold higher risk (odds ratio, 12.1; 95% confidence interval, 2.17-66.96; P < .01) of 30-day mortality or loss of independence, independent of the vascular procedure undertaken. CONCLUSIONS: The CFS is a practical tool for assessing preoperative frailty among patients undergoing elective major vascular surgery and can be used to predict likelihood of requiring discharge to a nursing facility or death after surgery. The identification of frail patients before major surgery can help manage postoperative expectations and optimize transitions of care.

Clinical effectiveness of open thrombectomy for thrombosed autogenous arteriovenous fistulas and grafts.

OBJECTIVE: Arteriovenous (AV) fistulas are the preferred hemodialysis access for patients with end-stage renal disease, although multiple interventions are typically needed to maintain patency. When AV fistulas thrombose, however, there is debate as to whether open thrombectomy should be attempted, particularly for salvage of upper arm fistulas. This study was designed to evaluate outcomes after open thrombectomy of upper arm and forearm AV fistulas compared with AV grafts. METHODS: We identified all patients who underwent an open thrombectomy procedure for a thrombosed AV fistula or graft at a single academic medical center between January 2006 and March 2017. The specific type of AV fistula or graft was evaluated, as were the patients' demographics, comorbidities, medications, adjunctive procedures during thrombectomy, and secondary interventions. The primary outcome measures, postintervention primary patency and postintervention secondary patency, were analyzed using Kaplan-Meier curves and Cox regression models for risk adjustment. RESULTS: During the study period, 209 open thrombectomy procedures were performed in 139 patients; 73 (35%) were undertaken in AV fistulas and 136 (65%) in grafts. Patients with upper arm fistulas (n = 52; 54% brachiocephalic, 46% brachiobasilic) and forearm fistulas (n = 16) were more likely to be male but less likely to have cerebrovascular disease or ischemic heart disease and to be receiving anticoagulation therapy compared with graft patients. After thrombectomy, the majority of patients underwent dialysis successfully (70% upper arm fistulas, 56% forearm fistulas, 63% grafts; P > .05), and 1-year survival rates were similar in all three cohorts. Postintervention primary patency at 1 year was significantly higher for AV fistulas vs grafts (33% for upper arm fistulas and 25% for forearm fistulas vs 9% for grafts; P < .05), which was confirmed in multivariate analysis, where upper arm AV fistulas had a 46% lower risk of recurrent thrombosis or secondary intervention (hazard ratio, 0.56; 95% confidence interval, 0.35-0.85; P < .05). Postintervention secondary patency at 1 year was similar between AV fistulas and grafts (44% for upper arm fistulas vs 43% for forearm fistulas vs 31% for grafts; P = .16), but in multivariate analysis, upper arm fistulas were significantly less likely to fail (hazard ratio, 0.63; 95% confidence interval, 0.40-1.00; P = .05). CONCLUSIONS: Our data suggest that AV fistula thrombectomy is successful in up to 70% of cases, with significantly improved risk-adjusted 1-year primary and secondary patency rates for upper arm fistulas compared with grafts. Whereas the risk of access failure is high after thrombectomy, efforts to salvage upper arm AV fistulas are effective in most patients and should be undertaken when feasible.

Comparative effectiveness of one-stage versus two-stage basilic vein transposition arteriovenous fistulas.

OBJECTIVE: Basilic vein transposition (BVT) fistulas may be performed as either a one-stage or two-stage operation, although there is debate as to which technique is superior. This study was designed to evaluate the comparative clinical efficacy and cost-effectiveness of one-stage vs two-stage BVT. METHODS: We identified all patients at a single large academic hospital who had undergone creation of either a one-stage or two-stage BVT between January 2007 and January 2015. Data evaluated included patient demographics, comorbidities, medication use, reasons for abandonment, and interventions performed to maintain patency. Costs were derived from the literature, and effectiveness was expressed in quality-adjusted life-years (QALYs). We analyzed primary and secondary functional patency outcomes as well as survival during follow-up between one-stage and two-stage BVT procedures using multivariate Cox proportional hazards models and Kaplan-Meier analysis with log-rank tests. The incremental cost-effectiveness ratio was used to determine cost savings. RESULTS: We identified 131 patients in whom 57 (44%) one-stage BVT and 74 (56%) two-stage BVT fistulas were created among 8 different vascular surgeons during the study period that each performed both procedures. There was no significant difference in the mean age, male gender, white race, diabetes, coronary disease, or medication profile among patients undergoing one- vs two-stage BVT. After fistula transposition, the median follow-up time was 8.3 months (interquartile range, 3-21 months). Primary patency rates of one-stage BVT were 56% at 12-month follow-up, whereas primary patency rates of two-stage BVT were 72% at 12-month follow-up. Patients undergoing two-stage BVT also had significantly higher rates of secondary functional patency at 12 months (57% for one-stage BVT vs 80% for two-stage BVT) and 24 months (44% for one-stage BVT vs 73% for two-stage BVT) of follow-up (P < .001 using log-rank test). However, there was no significant difference between groups in use of interventions (58% for one-stage BVT vs 51% for two-stage BVT; P = .5) to maintain patency. These findings were confirmed in multivariate analysis, in which two-stage BVTs were associated with a significantly lower rate of failure (hazard ratio, 0.39; 95% confidence interval, 0.2-0.8; P < .05) than one-stage BVTs after controlling for confounding variables. Finally, the two-stage BVT was more cost-effective (3.74 QALYs for two-stage BVT vs 3.32 QALYs for one-stage BVT) during 5 years, with an incremental cost-effectiveness ratio of $4681 per QALY. CONCLUSIONS: Our data show that two-stage BVTs are more durable and cost-effective than one-stage procedures, with significantly higher patency and lower rates of failure among comparable risk-stratified patients. These findings suggest that additional upfront costs and resources associated with creating two-stage BVTs are justified by their long-term outcomes.

Rapid Methods for Routine Frailty Assessment during Vascular Surgery Clinic Visits.

BACKGROUND: Frailty assessment can help vascular surgeons predict perioperative risk and long-term mortality for their patients. Unfortunately, comprehensive frailty assessments take too long to integrate into clinic workflow. This study was designed to evaluate 2 rapid methods for assessing frailty during vascular clinics-a short patient-reported survey and a provider-reported frailty scale. METHODS: We prospectively enrolled 159 patients presenting to an academic medical center vascular surgery clinic between May and November 2016. Patients underwent frailty assessment using 2 rapid methods: (1) the Frail Nondisabled (FiND) survey (5 questions) and (2) the Clinical Frailty Scale (CFS; 9-point scale from robust to severely frail). These were followed by administering the Fried Index, a validated frailty assessment method with 5 measures (weight loss, exhaustion, grip strength, walking speed, and activity level). The correlation between Fried scores (reference standard) with frailty diagnoses derived from FiND and CFS was analyzed using the Spearman-rank test, Cohen's kappa, sensitivity/specificity tests, and receiver operating curves. RESULTS: The evaluated cohort included 87 (55%) females, a mean age of 61 years, 126 (79%) preoperative patients, and 32 (20%) categorized as frail using the Fried Index criteria. The FiND survey was very sensitive (91%) but less specific for diagnosing frailty. In comparison, the CFS was highly specific (96%) for diagnosing frailty and exhibited high inter-rater reliability between surgeon and medical assistant scores (kappa: 0.79; 95% CI: 0.72-0.87; P < 0.001). There was moderate correlation between frailty assigned using the Fried Index and the CFS (rho: 0.41-0.44). CONCLUSIONS: Frailty can be quickly and effectively assessed during vascular surgery clinic using a combination of patient-reported (FiND) and provider-reported (CFS) methods to improve diagnostic accuracy. Implementing routine frailty assessment into clinic workflow can be a valuable tool for risk prediction and surgical decision-making.

Cardiac Stress Testing during Workup for Abdominal Aortic Aneurysm Repair Is Not Associated with Improved Patient Outcomes.

BACKGROUND: Cardiac stress testing (CST) is commonly used to help determine whether patients with abdominal aortic aneurysms (AAAs) are better candidates for open versus endovascular repair, although it is unknown whether the use of CST achieves its goal of optimizing patient selection and postoperative outcomes. METHODS: We retrospectively identified 3,635 patients in the Vascular Quality Initiative database (2010-2012) with an AAA ≥ 5.0 cm who were candidates for either open or endovascular AAA repair. The Vascular Study Group Cardiac Risk Index (VSG-CRI) was used to stratify patient risk. We applied generalized estimating equations with inverse probability weighting (IPW) to adjust for patient factors and hospital-level CST utilization to evaluate the effect of CST on composite of 30-day major adverse cardiac events or mortality (MACE-M) following AAA repair. RESULTS: CST was utilized in 1,627 (45%) patients during AAA workup, including 451 of 794 (57%) patients selected for open repair and 1,176 of 2,841 (41%) selected for endovascular repair. After IPW, the use of CST was not associated with the probability of patients receiving open versus endovascular repair (OR: 1.00; 95% CI: 0.77-1.32). As compared to patients without CST during AAA workup, adjusted analyses revealed that CST utilization was not associated with improved MACE or mortality outcomes following AAA repair. Among patients receiving CST, an abnormal CST was not significantly associated with selection of open versus endovascular repair or with postoperative outcomes after adjustment for the VSG-CRI score. Similar results were found for patients with either low or high VSG-CRI scores. CONCLUSIONS: Utilization of CST during workup for AAA is not associated with procedure selection and improved outcomes. Identifying risk factors for individuals who would benefit from preoperative CST before AAA repair will help reduce health care utilization and improve postoperative outcomes.

Intraoperative blood product resuscitation and mortality in ruptured abdominal aortic aneurysm.

OBJECTIVES: The resuscitation of patients with ruptured abdominal aortic aneurysms (RAAAs) has not been well studied, and the potential benefit of autotransfusion (AT) is unknown. The increased use of fresh-frozen plasma (FFP) has been associated with decreased mortality rates in trauma patients and may also improve RAAA survival. We explored the influence of intraoperative AT and FFP resuscitation on mortality rates in massively transfused RAAA patients. METHODS: A single-center review of RAAA patient records from April 1989 to October 2009 was undertaken. Clinical data and outcomes were studied. Operative and anesthesia records were queried for intraoperative transfusion totals. Massive transfusion was defined as ≥10 units of red blood cells (RBCs) inclusive of AT units. RESULTS: We identified 151 RAAA patients, of which 89 (60%) received a massive transfusion and comprised the study population. These 89 patients had an in-hospital mortality rate of 44%. Univariate predictors of mortality included increased age, preoperative hypotension, operative blood loss, and crystalloid, RBCs, and FFP volume. AT was used in 85 patients, with an increased ratio of AT:RBC units associated with survival. Mortality was 34% with AT:packed RBCs (PRBC) ≥1 (high AT) and 55% with AT:PRBC of <1 (low AT; P = .04). On multivariate analysis, age > 74 years (P = .03), lowest preoperative systolic blood pressure (SBP) <90 mm Hg (P = .06), blood loss >6 liters (P = .06), and low AT (P = .02) independently predicted mortality. The mean RBC:FFP ratio was similar in those that died (2.7) and in those that lived (2.9; P = .66). RBC:FFP ≤2 (high FFP) was present in 38 (43%) patients, with mortality of 49%. RBC:FFP >2 (low FFP) had 40% mortality (P = .39). RBC:FFP ratios decreased over time from 3.6 (years 1989 to 1999) to 2.2 (years 2000 to 2009; P < .001), but more liberal use of FFP was not associated with decreased mortality (47% vs 41%; P = .56). AT:PRBC ratios were stable over time (range, 1.4-1.2; P = .18). CONCLUSIONS: Greater use of AT but not of FFP was associated with survival in massively transfused RAAA patients. No mortality benefit was seen with increased FFP, but few patients had high FFP transfusion ratios. Further study to identify RAAA patients at risk for massive transfusion should be undertaken and a potentially greater role for AT in RAAA resuscitation investigated.

National trauma databank analysis of mortality and limb loss in isolated lower extremity vascular trauma.

OBJECTIVES: Lower extremity injury is common in trauma patients; however, the influence of arterial injury on devastating patient and limb outcomes can be confounded by the presence and physiological derangement of concomitant head or thoracoabdominal injuries. We analyzed isolated lower extremity injuries with an arterial component. Our aim was to elucidate factors associated with mortality and limb loss in this selected population. METHODS: We reviewed trauma incidents from the National Trauma Data Bank (2002-2006) containing isolated lower extremity injury codes and a specified infrainguinal arterial injury. Demographics, injury patterns, clinical characteristics, and adverse outcomes (death, amputation) during initial hospitalization were collected. Multivariate logistic regression was used to identify risk factors for limb loss. RESULTS: There were 651 isolated infrainguinal arterial injuries. Death (18) and early limb loss (42) were studied by mechanism (penetrating, n = 431; blunt, n = 220). Half of the deaths involved injury to the common femoral artery (CFA), and over 80% had injury to the CFA or superficial femoral artery (SFA). Death was three times as frequent in the CFA/SFA than in the popliteal/tibial injuries (P = .02). Penetrating injuries were present in almost 80% of deaths, and most of these were gunshot wounds. Patients who died had mean initial systolic blood pressure of 59.7 mm Hg, and almost 40% had no blood pressure on arrival. Mean initial Glasgow Coma Score was 4.5, and almost 80% arrived with a Glasgow Coma Score of 3 despite the absence of head injury. Twenty-seven above- and 15 below-the-knee amputations were performed. The popliteal artery was injured in half of the amputations, with injury isolated to the popliteal or tibial arteries in about three-quarters. Amputation was twice as frequent in popliteal/tibial than CFA/SFA injury (P = .03) and twice as frequent in blunt than penetrating injury (P = .05). Multiple arterial injuries (odds ratio, 5.2; 95% confidence interval, 1.7-15.6; P = .003), and fracture (odds ratio, 2.2; 95% confidence interval, 1.1-4.2; P = .02) independently predicted amputation, while the presence of nerve injury and soft tissue disruption did not. CONCLUSIONS: Isolated lower extremity trauma with vascular injury has a nearly 10% rate of mortality or limb loss. Mortality is associated with penetrating mechanism and early shock, likely resulting from prehospital proximal arterial hemorrhage. In contrast, early limb loss is more common with blunt distal vascular injury, especially to the popliteal and tibial arteries. Neither nerve nor soft tissue injury predicted limb loss but may result in delayed amputations not captured in this acute outcomes dataset.

A design modification to minimize tilting of an inferior vena cava filter does not deliver a clinical benefit.

OBJECTIVE: In July 2007, our group began to use a modified conical inferior vena cava filter with additional stabilizing struts designed to reduce tilting of retrievable filters. We analyzed our experience with this modified filter (Cook Medical, Bloomington, Ind) from July 1, 2007 to December 31, 2008 and compared it to our experience with the standard filter (Günther Tulip, Cook Medical, Bloomington, Ind) from January 1, 2006 through December 31, 2008 to determine if adoption of the modified filter reduced tilting and delivered a discernible clinical benefit. METHODS: The primary outcome measure was tilt angle after deployment. Secondary outcomes were change in tilt angle between deployment and retrieval (self-centering) and retrieval failure due to inability to engage the filter hook. Measurements were retrospectively determined using the anteroposterior venogram at the time of placement and removal. Tilt angle was defined by the center line of the filter relative to the center line of the inferior vena cava (IVC). Statistical significance was assumed for P ≤ .05. RESULTS: During the study period, a total of 302 IVC filters were placed. Retrieval was attempted for 85 of 194 (44%) standard filters and 52 of 108 (48%) modified filters. The overall difference in tilt angle (degrees) between the standard (median [interquartile range] = 5 [3, 8]) and modified (5 [3, 8]) filters at the time of placement was not statistically significant (P = .44). Modified filters deployed through a femoral route (8 [4, 11]) had significantly greater tilt angles than modified filters deployed using jugular access (4 [2, 6]; P < .0001). At the time of retrieval, evidence of self-centering was observed more often with modified (32 of 52 [62%]) than standard (36 of 85 [42%]) filters (P = .03). Overall, there were only four failures to retrieve the filter due to excess tilting (standard, 3 of 85 [4%], modified, 1 of 52 [2%]; P = .59). CONCLUSION: Overall, tilt angle at insertion did not differ between the modified and standard filters, although more modified filters displayed self-centering. There was no difference between the groups in retrieval failure due to excess tilting. Despite its greater tendency to self-center, we did not recognize a measurable clinical advantage of the modified filter.

Embolic atrial myxoma causing aortic and carotid occlusion.

BACKGROUND: Cardiac myxomas are a rare but well-described cause of stroke that usually occur in young people. Cardiac myxoma can embolize to multiple sites throughout the body. CASE DESCRIPTION: A 45-year-old woman presented acutely with altered mental status and signs of lower extremity vascular occlusion. Pathologic studies confirmed the diagnosis of cardiac myxoma. CONCLUSIONS: This is the first case reported in the English literature of simultaneous aortic and internal carotid artery occlusion from embolism of an atrial myxoma without evidence of intracardiac tumor on transesophageal echocardiogram.

Increasing use of endovascular therapy in acute arterial injuries: analysis of the National Trauma Data Bank.

OBJECTIVE: The application of endovascular technology for the emergency treatment of traumatic vascular injuries is a new frontier. This study examines recent nationwide use of endovascular therapy in acute arterial traumatic injuries. METHODS: This retrospective study used the National Trauma Data Bank (NTDB). Cases with a diagnosis of arterial vascular injury were identified according to the International Classification of Diseases, Ninth Revision, Clinical Modification, and procedure codes for endovascular therapy were selected. A descriptive analysis and multiple regressions were performed to identify variables predictive of outcomes. RESULTS: From 1994 to 2003, 12,732 arterial injuries were identified. Between 1997 (when the first endovascular repair was recorded in the NTDB) and 2003, 7286 open arterial repairs and 281 endovascular repairs were recorded for an overall utilization rate for endovascular procedures of 3.7%. The yearly number of endovascular procedures registered in the NTDB increased 27-fold, from four in 1997 to 107 in 2003. Use of stents substantially increased from 12 in 2000 to 30 in 2003; endograft use increased from one in 2000 to 37 in 2003. Nearly equal numbers of blunt (n = 134) and penetrating (n = 111) injuries were treated. The injury severity score (median, interquartile range [IRQ]) was significantly lower in patients who underwent an endovascular procedure at 13 (IRQ, 9 to 26) for trauma vs patients requiring an open procedure at 20 (IRQ, 10 to 34; P < .001), a finding corroborated by the lower number of associated injuries in patients undergoing endovascular repair (8.7 +/- 7.2 vs 13.0 +/- 16.1, P < .001). Using multivariable regression to control for differences in injury severity score and associated injuries, mortality was significantly lower for patients undergoing endovascular procedures (odds ratio, 0.18; P = .029) including those with an arterial injury of the torso or head and neck (odds ratio, 0.51, P = .007). Total length of hospital stay also tended to be lower for patients undergoing endovascular procedures by 18% (P = .064). CONCLUSION: The use of endovascular therapy in the setting of acute trauma is increasing in a dramatic fashion and is being used to treat a wide variety of vessels injured by blunt and penetrating mechanisms. Endovascular therapy appears to be particularly suitable for patients who present with less severe injuries and greater hemodynamic stability. These preliminary data suggest that the use of endovascular therapy for acute traumatic arterial injuries yields shorter lengths of stay and improved survival.

A ruptured pancreaticoduodenal artery aneurysm repaired by combined endovascular and open techniques.

Aneurysms of the pancreaticoduodenal arteries (PDA) are rare, accounting for <2% of all visceral aneurysms. An association with celiac artery stenosis has been reported. Many present with rupture, and a high mortality can be expected. Treatment is therefore challenging. Arterial ligation, anuerysmectomy, or bypass has been the mainstay of treatment. We recently treated a patient (who had no celiac axis) with a ruptured PDA aneurysm with combined open and endovascular techniques. A 46-year-old man was transferred to our hospital with a 1-day history of abdominal pain and syncope. On admission, an abdominal and pelvis computerized tomographic (CT) scan identified a large mesenteric hematoma, a 1.9 cm PDA aneurysm, and an occluded celiac axis. Mesenteric angiography revealed no active aneurysm leak and a stenotic superior mesenteric artery (SMA) origin. All hepatic blood flow originated from the stenotic SMA via markedly enlarged PDA collaterals. The patient was brought to the operating room, where absence of the celiac axis was confirmed. An aorto-to-proper hepatic and SMA bypass was performed using a bifurcated polyester graft. The next day, the patient was brought to the angiography suite, where the PDA aneurysm was coiled. Postprocedure CT scans confirmed thrombosis of the aneurysm. Ruptured mesenteric artery aneurysms are a challenging problem for the vascular surgeon. PDA aneurysms are rare and often occur in an unfavorable location. There appears to be an association with anatomic anomalies of the mesenteric circulation. Prompt invasive and noninvasive diagnostic studies aid in the definitive management of this often fatal problem. Combined endovascular and open techniques can be used for successful treatment.

Meeting AHA/ACC secondary prevention goals in a vascular surgery practice: an opportunity we cannot afford to miss.

OBJECTIVE: In an effort to reduce cardiovascular mortality, patients with atherosclerotic arterial disease should undergo risk factor modification according to the American Heart Association/American College of Cardiology (AHA/ACC) Secondary Prevention Guidelines (hereafter, Guideline). We assessed compliance with the Guideline in a group of patients seen in a vascular surgery practice. METHODS: We evaluated 200 consecutive patients with lower-extremity occlusive disease, cerebrovascular disease, or abdominal aortic aneurysm seen by a university-based vascular surgery practice. The subjects were patients who had been seen previously in our clinic (ESTABLISHED) and new referrals (NEW). Data pertinent to each of the nine AHA/ACC Guideline goals were collected from patient interviews, medication histories, and laboratory records. Compliance with each of the Guideline goals was evaluated. Differences in compliance between ESTABLISHED and NEW patient groups were also compared. We also recorded whether a patient had a previous endovascular or open surgical vascular intervention (EVENT or NO EVENT). Differences in compliance between the EVENT and NO EVENT groups were compared. RESULTS: Most patients did not achieve the secondary prevention goals recommended in the Guideline. Patients who had a prior vascular intervention (EVENT) were significantly more likely to achieve goals for low-density lipoprotein level (43% vs 23%), and for statin (71% vs 39%), beta-blocker (46% vs 27%), angiotensin-converting enzyme inhibitor (53% vs. 35%), and antiplatelet agent (85% vs. 68%) use (P < .05). ESTABLISHED patients were significantly more likely than NEW patients to have a prior EVENT (87% vs 47%, P < .0005). ESTABLISHED patients were significantly more likely than NEW patients to achieve goals for low-density lipoprotein level, beta-blocker, and statin use; however, these differences were likely due to the higher proportion of EVENT patients in the ESTABLISHED group. CONCLUSION: Compliance with the Guideline is suboptimal in patients with atherosclerotic arterial disease. Secondary prevention goals were more often achieved in the EVENT patient group, suggesting that a vascular intervention may lead to increased patient and physician awareness and compliance with the Guideline. A targeted effort towards risk factor modification in patients with atherosclerotic arterial disease could improve compliance with the Guideline and reduce cardiovascular mortality.