Justin B. Hurie

Anesthesia-Based Evaluation of Outcomes of Lower-Extremity Vascular Bypass Procedures

BACKGROUND This report examines the effects of regional versus general anesthesia for infrainguinal bypass procedures performed in the treatment of critical limb ischemia (CLI). METHODS Nonemergent infrainguinal bypass procedures for CLI (defined as rest pain or tissue loss) were identified using the 2005 to 2008 American College of Surgeons National Surgical Quality Improvement Program database using International Classification of Disease, ninth edition, and Current Procedure Terminology codes. Patients were classified according to National Surgical Quality Improvement Program data as receiving either general anesthesia or regional anesthesia. The regional anesthesia group included those specified as having regional, spinal, or epidural anesthesia. Demographic, medical, risk factor, operative, and outcomes data were abstracted for the study sample. Individual outcomes were evaluated according to the following morbidity categories: wound, pulmonary, venous thromboembolic, genitourinary, cardiovascular, and operative. Length of stay, total morbidity, and mortality were also evaluated. Associations between anesthesia types and outcomes were evaluated using linear or logistic regression. RESULTS A total of 5,462 inpatient hospital visits involving infrainguinal bypasses for CLI were identified. Mean patient age was 69 ± 12 years; 69% were Caucasian; and 39% were female. In all, 4,768 procedures were performed using general anesthesia and 694 with regional anesthesia. Patients receiving general anesthesia were younger and significantly more likely to have a history of smoking, previous lower-extremity bypass, previous amputation, previous stroke, and a history of a bleeding diathesis including the use of warfarin. Patients receiving regional anesthesia had a higher prevalence of chronic obstructive pulmonary disease. Tibial-level bypasses were performed in 51% of procedures, whereas 49% of procedures were popliteal-level bypasses. Cases performed using general anesthesia demonstrated a higher rate of resident involvement, need for blood transfusion, and operative time. There was no difference in the rate of popliteal-level and infrapopliteal-level bypasses between groups. Infrapopliteal bypass procedures performed using general anesthesia were more likely to involve prosthetic grafts and composite vein. Mortality occurred in 157 patients (3%). The overall morbidity rate was 37%. Mean and median lengths of stay were 7.5 days (± 8.1) and 6.0 days (Q1: 4.0, Q3: 8.0), respectively. Multivariate analyses demonstrated no significant differences by anesthesia type in the incidence of morbidity, mortality, or length of stay. CONCLUSION These results provide no evidence to support the systematic avoidance of general anesthesia for lower-extremity bypass procedures. These data suggest that anesthetic choice should be governed by local expertise and practice patterns.

Influence of computed tomography angiography reconstruction software on anatomic measurements and endograft component selection for endovascular abdominal aortic aneurysm repair

OBJECTIVE Three-dimensional (3D) centerline reconstruction of computed tomography angiography (CTA) images permits detailed anatomic characterization of abdominal aortic aneurysms and facilitates planning of endovascular repair. Although several programs for 3D CTA reconstruction and measurement are available, direct comparisons have not been published, and reliability between software platforms has not been characterized. We evaluated agreement between anatomic measurements obtained from 3D CTA reconstructions using three commercially available software programs and characterized concordance between the programs for endograft component selection. METHODS Images from 92 CTA studies performed before abdominal aortic aneurysm repair were reconstructed and measured using three different software programs: independent reconstruction with proprietary software (Preview; M2S Inc, Lebanon, NH), surgeon-based reconstruction with proprietary software (AquariusNet Thin Client; TeraRecon Inc, San Mateo, Calif), and surgeon-based reconstruction with open-source software (Osirix MD; Pixmeo, Geneva, Switzerland). Agreement between outer wall diameter and length measurements obtained from centerline reconstructions created with each program was evaluated using scatter plots, intraclass correlation coefficients, and Bland-Altman plots. Concordance between aortic and iliac endograft component diameters selected from measurements with each program based on published instructions for use was examined using weighted κ statistics. RESULTS Diameter measurements were generally similar between programs. Mean diameters at all locations were within ≤ 1 mm of one another, and mean length measurements were within ≤ 10 mm of one another for all pairwise comparisons. Intraclass correlations coefficients between programs for diameter measurements were comparable between programs (≥ 0.82 for all diameter comparisons and ≥ 0.88 for all length comparisons) and indicated good correlation. Pair-wise comparisons indicated similar rates of identical and adjacent size endograft component selection without an obvious trend toward superior agreement for any two programs. Rates of identical proximal endograft diameter selection ranged from 46% to 59%, whereas 89% to 100% of proximal endograft diameters selected between programs were within one adjacent (smaller or larger) size of each other. For iliac endograft selection, rates of identical component diameter selection between programs ranged from 36% to 69%, and 58% to 99% of selected iliac endograft diameters were within one adjacent size. CONCLUSIONS Outer wall diameter and centerline length measurements obtained from 3D CTA reconstructions demonstrated good correlation between imaging analysis software programs, and graft diameter selections based on these measurements were reasonably similar. Comparable 3D CTA reconstruction measurements can be generated from independent and surgeon-based approaches using proprietary and open-source software, and the selection of a method to interpret images for endograft planning can be individualized according to operator experience and available resources while retaining sufficient accuracy.

Grip strength measurement for frailty assessment in patients with vascular disease and associations with comorbidity, cardiac risk, and sarcopenia

Objective: Frailty is associated with adverse events, length of stay, and nonhome discharge after vascular surgery. Frailty measures based on walking‐based tests may be impractical or invalid for patients with walking impairment from symptoms or sequelae of vascular disease. We hypothesized that grip strength is associated with frailty, comorbidity, and cardiac risk among patients with vascular disease. Methods: Dominant hand grip strength was measured during ambulatory clinic visits among patients with vascular disease (abdominal aortic aneurysm [AAA], carotid stenosis, and peripheral artery disease [PAD]). Frailty prevalence was defined on the basis of the 20th percentile of community‐dwelling population estimates adjusted for age, gender, and body mass index. Associations between grip strength, Charlson Comorbidity Index (CCI), Revised Cardiac Risk Index (RCRI), and sarcopenia (based on total psoas area for patients with cross‐sectional abdominal imaging) were evaluated using linear and logistic regression. Results: Grip strength was measured in 311 participants; all had sufficient data for CCI calculation, 217 (69.8%) had sufficient data for RCRI, and 88 (28.3%) had cross‐sectional imaging permitting psoas measurement. Eighty‐six participants (27.7%) were categorized as frail on the basis of grip strength. Frailty was associated with CCI (odds ratio, 1.86; 95% confidence interval, 1.34‐2.57; P = .0002) in the multivariable model. Frail participants also had a higher average number of RCRI components vs nonfrail patients (mean ± standard deviation, 1.8 ± 0.8 for frail vs 1.5 ± 0.7 for nonfrail; P = .018); frailty was also associated with RCRI in the adjusted multivariable model (odds ratio, 1.75; 95% confidence interval, 1.16‐2.64; P = .008). Total psoas area was lower among patients categorized as frail vs nonfrail on the basis of grip strength (21.0 ± 6.6 vs 25.4 ± 7.4; P = .010). Each 10 cm2 increase in psoas area was associated with a 5.7 kg increase in grip strength in a multivariable model adjusting for age and gender (P < .0001). Adjusted least squares mean psoas diameter estimates were 25.5 ± 1.1 cm2 for participants with AAA, 26.7 ± 2.0 cm2 for participants with carotid stenosis, and 22.7 ± 0.8 cm2 for participants with PAD (P = .053 for PAD vs AAA; P = .057 for PAD vs carotid stenosis; and P = .564 for AAA vs carotid stenosis). Conclusions: Grip strength is useful for identifying frailty among patients with vascular disease. Frail status based on grip strength is associated with comorbidity, cardiac risk, and sarcopenia in this population. These findings suggest that grip strength may have utility as a simple and inexpensive risk screening tool that is easily implemented in ambulatory clinics, avoids the need for imaging, and overcomes possible limitations of walking‐based measures. Lower mean psoas diameters among patients with PAD vs other diagnoses may warrant consideration of specific approaches to morphomic analysis.

Effects of Case Timing and Care Team Composition on Hospital Operating Room Costs for Routine Endovascular Procedures

Background: The contemporary health care environment is complex, with mounting pressures to perform greater procedural volumes with less support staff to minimize costs and to maximize efficiency. This report details an analysis of routine endovascular procedures performed in a hybrid operating room with dedicated vascular support staff during daytime hours compared with similar cases performed after hours with general operating room staff. Methods: All lower extremity endovascular cases during a 25-month period were identified by Current Procedural Terminology codes from a query of our institutional operating room database. Emergent/urgent cases and cases with associated open surgical procedures were excluded. Cases were divided by the time of day and available clinical support structure into two groups according to procedure start time: specialty-specific daytime (SS), with case starting between 7 AM and 3 PM weekdays; and general staff after hours (AH) for all others. The resulting case list was examined by case type according to SS or AH designation, and case types occurring disproportionately during either time frame were excluded to create the most similar case type distribution among the two groups for analytic purposes. Demographics, case specifics, and cost data were then obtained from the electronic health record and our enterprise cost data warehouse. Multivariable mixed linear modeling was used to examine component costs (eg, anesthesia, supplies) and total costs controlling for a number of factors that could affect cost. Results: There were 275 routine endovascular-only procedures performed on 250 patients examined (203 SS, 47 AH). AH patients were younger, more likely to be female, and less likely to be taking antiplatelet agents at the time of the procedure than SS patients. Scheduled, elective cases made up 86% of SS cases and 55% of AH cases. No significant differences in procedure specifics were observed between the groups (number and location of access sites, type and number of interventions). Multivariable analyses controlled for factors affecting costs (including posting type, American Society of Anesthesiologists class, number of access sites, and interventional vs diagnostic case status). Costs associated with anesthesia (cost ratio, 1.85; P < .001), operating room supplies (cost ratio, 1.45; P 1⁄4 .01), and postanesthesia recovery (cost ratio, 1.20; P 1⁄4 .035) were all significantly increased in AH cases compared with SS cases. The average total hospital cost for routine endovascular cases performed AH was

PC162 Exploring Associations Between Sleep Disturbance and Walking Activity Among Patients With Symptomatic Peripheral Artery Disease: Results From the Project VOICE Pilot Study

9010 compared with

Chronic furosemide administration blunts renal BOLD magnetic resonance response to an acute furosemide stimulus in patients being evaluated for renal artery revascularization

6143 for SS cases (cost ratio, 1.47; P < .001). Conclusions: Performance of routine endovascular cases by specialtyspecific teams during regular hospital hours was associated with significantly less cost to the hospital system, with a w50% increase in total cost associated with AH cases. In the current health care environment, investments in specialty-specific teams and process improvements to facilitate case performance with these teams are likely to be cost-effective.

Chronic diuretic therapy attenuates renal BOLD magnetic resonance response to an acute furosemide stimulus

Objectives: For over 50 years, standard endarterectomy with patch (SEP) of the common femoral artery (CFA) has been well described with durable results. Eversion endarterectomy (EE) uses a complete CFA transection above its bifurcation and subsequent end-to-end anastomosis. EE is potentially advantageous over SEP by avoiding prosthetic patch infection and easing future transfemoral access. With subjectively more focal femoral artery lesions encountered during the endovascular era, we reviewed our SEP and EE outcomes to see whether there were any differences between the two methods. Methods: We retrospectively identified all patients undergoing CFA endarterectomy by a single surgeon who adopted preferential EE at a single institution between 2007 and 2015. Patient demographics and surgical details were captured from the electronic medical record, including endarterectomy type and the performance of concurrent endovascular and/or bypass surgery. Complications and adverse events were recorded. Statistical comparison of means was performed using the t-test, and categoric variables were evaluated using the Fisher exact test. Results: Eighty-nine sequentially encountered patients underwent 97 endarterectomies of the CFA (68 SEP and 29 EE). More SEP than EE cases were performed concomitant with either bypass or stenting (62% vs 34%). Most patients were smokers (80% of SEP vs 93% of EE). Patients undergoing EE were older (67 vs 62 years; P 1⁄4 .01), with less hypertension (59% vs 79%; P 1⁄4 .04), and less chronic kidney disease (4% vs 27%; P 1⁄4 .01). The observed frequencies of diabetes, dyslipidemia, coronary artery disease, stroke, coagulopathy, and cancer were not significantly different among EE and SEP patients. The average follow-up duration was 28 months, longer among SEPs patients than EE patients (32 vs 20 months; P 1⁄4 .02). We observed favorable primary patency with EE (Table). There were no statistically significant differences observed among adverse events associated with SEP and EE patients (Fig): CFA restenoses (10% vs 3.4%), CFA thromboses (12% vs 0%), and wound infections (10% vs 7%). Conclusions: EE and SEP both offer reasonably durable outcomes for the treatment of focal femoral arterial occlusive disease. EE may offer an attractive alternative to SEP, potentially decreasing the risk of significant wound complications associated with prosthetic patch infections.

Endovascular Treatment of Chronic Mesenteric Ischemia in the Setting of Occlusive Superior Mesenteric Artery Lesions

Background Blood Oxygen Level Dependent (BOLD) magnetic resonance (MR) is a novel imaging tool that is able to detect tissue oxygenation and has recently been utilized to evaluate renal function in patients with renal artery stenosis (RAS). Renal BOLD imaging is typically performed before and after a furosemide stimulus to assess kidney viability. Furosemide blocks the sodium-potassium2chloride transporter, an oxygen-dependent process, in the ascending loop of Henle located in the renal medulla. Presumably, kidneys that are able to decrease oxygen consumption and increase BOLD (T2*) signal in response to furosemide would be viable and benefit from revascularization procedures. A standard dose of 20mg of intravenous (IV) furosemide is administered to evaluate renal responsiveness (increased T2* signal intensity) and viability. However, little is known about the effect of prior exposure to furosemide on the ability of BOLD MR techniques to evaluate renal function.