The risks of failed nonoperative management of appendicitis in older adults

BACKGROUND

The consequences of failed nonoperative management of appendicitis in older patients have not been described.

METHODS

We used the 2004-2017 National Inpatient Sample to identify acute appendicitis patients managed nonoperatively (<65 years old: 32,469; ≥65 years old: 11,265). Outcomes included morbidity, length of stay (LOS), inpatient costs, and discharge to skilled facilities. Differences were estimated using propensity scores.

RESULTS

For patients <65, nonoperative failure was associated with increased morbidity (7 ​% [95 ​% CI 6.9 ​%-8.1 ​%]), LOS (3 day [95 ​% CI 3-4]), costs ($9015 [95 ​% CI $8216- $9446]), and discharges to skilled facilities (1 ​% [95 ​% CI 0.9 ​%-1.6 ​%]) compared to successful nonoperative treatment. Patients ≥65 had differences in morbidity (14 ​% [95 ​% CI 13.6 ​%-16.2 ​%]), LOS (6 days [95 ​% CI 5-6]), costs ($15,964 [95 ​% CI $15,181- $17,708]), and discharges to skilled facilities (12 ​% [95 ​% CI: 10.0 ​%-13.3]) compared to nonoperative success.

CONCLUSIONS

Nonoperative management of appendicitis should be approached cautiously for older adults.

Is nonoperative management of appendicitis safe and effective in multi-morbid patients?

BACKGROUND

The purpose of this study was to (1) compare post-treatment outcomes of operative and nonoperative management of acute appendicitis in multi-morbid patients and (2) evaluate the generalizability of prior clinical trials by determining whether outcomes differ in multi-morbid patients compared to the young and healthy patients who resemble prior clinical trial participants.

METHODS

We conducted a retrospective cohort study using the National Inpatient Sample from 2004 to 2017. We included 368,537 patients with acute, uncomplicated appendicitis who were classified as having 0 or 2+ comorbidities. We compared inpatient morbidity, mortality, length of stay, and costs using propensity scores. Unmeasured confounding was addressed with probabilistic sensitivity analysis.

RESULTS

Overall, 5% of patients without comorbidities were treated nonoperatively versus 20% of multi-morbid patients. Compared to surgery, nonoperative management was associated with a 3.5% decrease in complications (95% confidence interval 3%-4%) for multi-morbid patients, but there was no significant difference for patients without comorbidity. However, nonoperative management was associated with a 1.5% increase in mortality for multimorbid patients (95% confidence interval 1.3%-1.7%). Costs and length of stay were lower for all patients treated with surgery. Probabilistic sensitivity analysis showed that results were robust to the effects of unmeasured confounding.

CONCLUSION

Our results raise concerns about the generalizability of clinical trials that compared nonoperative and operative management of appendicitis because (1) those trials enrolled mostly young and healthy patients, and (2) results in multi-morbid patients differ from outcomes in younger and healthier patients.

Association Between Coronavirus Disease 2019 Vaccination and Mortality After Major Operations

OBJECTIVE

The objective of this study was to compare postoperative 90-day mortality between (1) fully vaccinated patients with COVID-19-positive and negative diagnosis, and (2) vaccinated and unvaccinated patients with COVID-19 positive diagnosis.

BACKGROUND

Societal guidelines recommend postponing elective operations for at least 7 weeks in unvaccinated patients with preoperative coronavirus disease 2019 (COVID-19) infection. The role of vaccination in this infection-operation time risk is unclear.

METHODS

We conducted a national US multicenter retrospective, matched cohort study spanning July 2021 to October 2022. Participants were included if they underwent a high-risk general, vascular, orthopedic, neurosurgery, or genitourinary surgery. All-cause mortality occurring within 90 days of the index operation was the primary outcome. Inverse probability treatment weighted propensity scores were used to adjust logistic regression models examining the independent and interactive associations between mortality, exposure status, and infection proximity.

RESULTS

Of 3401 fully vaccinated patients in the 8-week preoperative period, 437 (12.9%) were COVID-19-positive. Unadjusted mortality rates were not significantly different between vaccinated patients with COVID-19 (22, 5.0%) and vaccinated patients without COVID-19 (99, 3.3%; P = 0.07). After inverse probability treatment weighted adjustment, mortality risk was not significantly different between vaccinated COVID-19-positive patients compared to vaccinated patients without COVID-19 (adjusted odds ratio = 1.38, 95% CI: 0.70, 2.72). The proximity of COVID-19 diagnosis to the index operation did not confer added mortality risk in either comparison cohort.

CONCLUSIONS

Contrary to risks observed among unvaccinated patients, postoperative mortality does not differ between patients with and without COVID-19 when vaccinated against the severe acute respiratory syndrome coronavirus 2 virus and receiving a high-risk operation within 8 weeks of the diagnosis, regardless of operation timing relative to diagnosis.

Transfusion trigger after operations in high cardiac risk patients (TOP) trial protocol. Protocol for a multicenter randomized controlled transfusion strategy trial

BACKGROUND

There is substantial uncertainty regarding the effects of restrictive postoperative transfusion among patients who have underlying cardiovascular disease. The TOP Trial's objective is to compare adverse outcomes between liberal and restrictive transfusion strategies in patients undergoing vascular and general surgery operations, and with a high risk of postoperative cardiac events.

METHODS

A two-arm, single-blinded, randomized controlled superiority trial will be used across 15 Veterans Affairs hospitals with expected enrollment of 1520 participants. Postoperative transfusions in the liberal arm commence when Hb is <10 g/ dL and continue until Hb is greater than or equal to 10 g/dL. In the restrictive arm, transfusions begin when Hb is <7 g/dL and continue until Hb is greater than or equal to 7 g/dL. Study duration is estimated to be 5 years including a 3-month start-up period and 4 years of recruitment. Each randomized participant will be followed for 90 days after randomization with a mortality assessment at 1 year.

RESULTS

The primary outcome is a composite endpoint of all-cause mortality, myocardial infarction (MI), coronary revascularization, acute renal failure, or stroke occurring up to 90-days after randomization. Events rates will be compared between restrictive and liberal transfusion groups.

CONCLUSIONS

The TOP Trial is uniquely positioned to provide high quality evidence comparing transfusion strategies among patients with high cardiac risk. Results will clarify the effect of postoperative transfusion strategies on adverse outcomes and inform postoperative management algorithms.

TRIAL REGISTRATION

http://clinicaltrials.gov identifier: NCT03229941.

Practical Guide to Designing a Clinical Trial in Surgery

This Guide to Statistics and Methods outlines the key elements that need to be considered during the design phase of a surgical clinical trial.

Comparison of Longitudinal Skeletal Thigh Muscle Findings With Magnetic Resonance Imaging in Patients With Peripheral Artery Disease With-Versus-Without Diabetes Mellitus

The aim of this secondary analysis of ELIMIT (The Effect of Lipid Modification on Peripheral Artery Disease after Endovascular Intervention Trial) was to determine longitudinal changes over 24 months in skeletal thigh muscle volumes and individual muscle compartments in patients with peripheral artery disease (PAD) with and without diabetes. A total of 48 patients with available magnetic resonance imaging of the distal superficial femoral artery at baseline and 2 years were included in this analysis. Muscle volumes and superficial femoral artery wall, lumen, and total vessel volumes were quantified. Intrareader reproducibility of muscle tracings was assessed with the intraclass correlation coefficient using a 2-way model. Baseline characteristics were similar between patients with PAD with and without diabetes, except for smoking history (p = 0.049), cholesterol levels (p <0.050), and calf walking pain (p = 0.049). Interobserver reproducibility of the muscle volume tracings was excellent for all muscle groups (all intraclass correlation coefficients >0.86, confidence interval 0.69 to 0.94). Total muscle and total leg volumes increased significantly between baseline and 24 months among patients with PAD without diabetes (31 ± 6.4 cm³ vs 32 ± 7.0 cm³, p <0.001; 18 ± 4.4 cm³ vs 19 ± 4.8 cm³, p = 0.045), whereas there was no change in patients with PAD and diabetes. Total muscle volume was inversely associated with age and body mass index in patients with PAD both with and without diabetes (p <0.05). In conclusion, magnetic resonance imaging-quantified thigh muscle volumes are highly reproducible and may be of interest in assessing PAD patients with and without diabetes.

Factors Associated with Preference of Choice of Aortic Aneurysm Repair in the PReference for Open Versus Endovascular repair of AAA (PROVE-AAA) study

OBJECTIVE

Patients can choose between open repair and endovascular repair of abdominal aortic aneurysm (AAA). However, the factors associated with patient preference for one repair type over another are not well characterized. Here we assess the factors associated with preference of choice for open or endovascular AAA repair among veterans exposed to a decision aid to help with choosing surgical treatment.

METHODS

Across 12 VA hospitals, veterans received a decision aid covering domains including patient information sources and understanding preference. Veterans were then given a series of surveys at different timepoints examining their preferences for open versus endovascular AAA repair. Questions from the preference survey were used in analyses of patient preference. Results were analyzed using chi-squared tests. A logistic regression was performed to assess factors associated with preference for open repair or preference for endovascular repair.

RESULTS

A total of 126 veterans received a decision aid informing them of their treatment choices, after which 121 completed all preference survey questions; five veterans completed only part of the instruments. Overall, veterans who preferred open repair were typically younger (70 vs 73, p=0.02), with similar rates of common comorbidities (coronary disease 16% vs 28%, p=0.21), and similar aneurysms compared to those who preferred endovascular repair (6.0 cm versus 5.7 cm, p=0.50). Veterans in both preference categories (28% of veterans preferring EVAR, 48% of veterans preferring open repair) reported "taking their doctor's" advice as the "top-box" response for the single most important factor influencing their decision. When comparing the tradeoff between less invasive surgery and higher risk of long-term complications, more than half of veterans preferring EVAR reported invasiveness as more important compared with approximately one in ten of those preferring open repair (53% versus 12%, p<0.001). Shorter recovery was an important factor for the endovascular repair group (74%) and not important in the open repair group (76%), p=0.5). In multivariable analyses, valuing a short hospital stay (OR=12.4, 95% CI 1.13-135.7) and valuing a shorter recovery (OR15.72, 95% CI 1.03-240.2) were associated with greater odds of preference for endovascular repair, while finding these characteristics not important were associated with greater odds of preference for open repair.

CONCLUSIONS

When faced with the decision of open repair versus endovascular repair, veterans who valued a shorter hospital stay and a shorter recovery were more likely to prefer endovascular repair, while those more concerned about long-term complications preferred open repair. Veterans typically value the advice of their surgeon over their own beliefs and preference. These findings need to be considered by surgeons as they guide their patients to a shared decision.

Racial and Ethnic Disparities in Abdominal Aortic Aneurysm Evaluation and Treatment Rates in Texas

INTRODUCTION

Screening identifies intact abdominal aortic aneurysm (iAAA) before progression to ruptured AAA (rAAA). However, screening efforts have been limited by low overall diagnostic yield and by unequal screening among minority populations. The goal was to identify equitable AAA screening strategies for both majority and minority populations.

METHODS

We performed epidemiological and geospatial analyses of inpatient and outpatient procedures for iAAA or rAAA at Texas hospitals from 2006 through 2014 at all non-federal hospitals and clinics in Texas. Data were aggregated by area (metropolitan statistical area or rural region), then supplemented by six additional data sources to estimate AAA repair incidence rates, rates of AAA-related clinic and ultrasonography visits, distance to providers, and location and number of unrecognized AAAs.

RESULTS

The majority of AAA repairs occurred among 65-84 year-old men in large metropolitan areas categorized as White. Area procedure rates for rAAA and iAAA were strongly correlated (R²=0.47). Two other variables-the proportions of persons categorized as White and persons aged ≥65 years in a region-identified subgroups within the majority population that were at high risk for iAAA (R²=0.46). Lower rates of clinic visits and AAA ultrasonograms were seen among persons categorized as Black. The several areas with disproportionately-higher rAAA:iAAA ratios were found, mainly affecting persons categorized as Black.

CONCLUSIONS

Multiple focused AAA screening strategies may be needed to address disproportionately-lower AAA identification among persons categorized as Black.

Treatment of Early Deep Wound Infections after Arterial Reconstructions: A Meta-Analysis and Survey

BACKGROUND

Peripheral vascular graft infections, a serious concern after open lower extremity interventions, are treated using multiple strategies. Yet, there is no consensus on the optimal treatment. This study summarizes the literature and compares aggregate effect sizes between graft preservation with antibiotic beads and total graft excision.

METHODS

Manuscripts published between 1972 and 2019 were systematically queried using Ovid Medline and PubMed. Studies were included if they described early (≤4 months of the index procedure) infection-related outcomes after extracavitary and infrainguinal arterial graft infections that were managed with antibiotic-loaded beads or total excisions. Outcomes assessed included the prevalence of graft preservation failure, reinfection, and major amputation. To examine current preferences on this subject, a voluntary, anonymous survey was administered to practicing members of the Society for Clinical Vascular Surgery.

RESULTS

Six graft preservation studies (n = 147 patients) were included in the meta-analysis, based on PRISMA guidelines. The meta-analytic pooled proportion of patients with: (1) graft preservation failure was 0.09 (95% CI: 0.00, 0.46, I² = 88.8%), (2) reinfection was 0.04 (95% CI: 0.00, 0.18, I² = 79.7%), and (3) major amputation was 0.00 (95% CI: 0.00, 0.04, I² = 0%). Five studies addressing total excisions were identified via the systematic review however, their combined sample size (n = 28 patients) impeded use of a meta-analysis. Ninety (19%) licensed surgeons participated in the survey. In a hemodynamically stable, nonseptic patient, 67% (60) of respondents routinely excise the graft, while 31% (28) prefer preservation.

CONCLUSIONS

Study design and patient characteristic-related heterogeneity limited our ability to generate robust, clinical evidence-level outcome estimates. A prospective study is necessary to definitively establish the efficacy of antibiotic beads in the treatment and preservation of vascular graft infections.

Outcomes after Endovascular Stent Placement for Long-Segment Superficial Femoral Artery Lesions

BACKGROUND

Endovascular intervention is commonly pursued as first-line management of symptomatic, long-segment superficial femoral artery (SFA) disease. The relative effectiveness and comparative long-term outcomes among bare metal stents (BMS), covered stents (CS), and drug-eluting stents (DES) for long-segment SFA lesions remain uncertain.

METHODS

A retrospective cohort study identified patients with symptomatic SFA lesions measuring at least 15 cm in length who successfully received an endovascular stent (BMS, CS, or DES). The outcomes were patency, patient presentation upon stent occlusion, amputation-free survival (AFS), and all-cause mortality. Proportional hazards regressions and a multinomial logistic regression model were used to control for significant confounders.

RESULTS

A total of 226 procedures were analyzed (BMS: 95 [42%]; CS: 74 [33%]; DES: 57 [25%]). There were no significant differences among the 3 stent types with respect to age, prevalence of either diabetes or end-stage renal disease, or smoking history. The median length of the SFA lesion varied across the cohorts (BMS: 28 cm [interquartile range, IQR 20-30]; CS: 26 cm [IQR 20-30]; DES: 20 cm [IQR 16-25]; P = 0.002). The unadjusted primary patency of BMS at 12, 24, and 48 month following index stent placement was 57%, 47%, and 44%, respectively. This is compared to 62%, 49%, and 42% for CS, and 81%, 66%, and 53% for DES, respectively (log-rank P = 0.044). In adjusted models, however, there were no significant differences in primary patency among the stent types. Compared to CS however, DES was associated with improved primary-assisted patency (hazard ratio [HR] for patency loss: 0.35, P = 0.008) and secondary patency (HR: 0.32, P = 0.011). Across the entire follow-up period, stent occlusions occurred in 38 (40%) BMS cases, 42 (57%) CS, and 11 (19%) DES (P < 0.001). Of these, acute limb ischemia (ALI) occurred in 2 (5%) BMS cases, 14 (33%) CS, and 1 (9%) DES (P = 0.010). After adjustment, the relative risk of presenting with ALI as opposed to claudication was 27 times greater among patients re-presenting with occluded CS compared to BMS (P = 0.020). There were no significant differences in AFS or all-cause mortality across the 3 cohorts.

CONCLUSIONS

For long-segment SFA lesions, DES is associated with improved primary-assisted and secondary patency over long-term follow-up. In the event of stent occlusion, CS is associated with an increased risk of ALI.

The Ever-Humbling Challenge of Peripheral Artery Disease Treatment Seen Across the Sexes

See Article Ramkumar et al

Delayed gratification and adherence to exercise among patients with claudication

Few studies have explicitly identified factors that explain an individual's willingness to engage in community-based exercise for claudication. Identifying the unique characteristics of those inclined toward physical activity would inform interventions that encourage walking. We examined the utility of behavioral economics-related concepts in understanding walking among Veterans with claudication. Patients who received care at the Michael E. DeBakey Veterans Affairs Medical Center in Houston, Texas, were surveyed on symptom severity, behavioral economics, stress, and depression. The primary outcome was a binary variable measuring current walking for exercise and defined as walking for at least 30 minutes every day. Multivariable logistic regression models were used to identify variables, both clinically and statistically significant, at a p-value < 0.05. Between April 2017 and March 2018, we received 148 (30%) responses. A total of 35% (n = 51) of respondents indicated that they walked recreationally for exercise compared to 65% (n = 94) who did not. Characteristics that were significantly associated with walking included regularly saving money (adjusted odds ratio (aOR) = 10.7, p = 0.001), seeking complex problem-solving (aOR = 0.12, p = 0.002), and severe symptoms (aOR = 0.24, p = 0.017). Individuals describing a preference for the future rather than immediate benefit also reported currently walking for exercise. Defining the characteristics of those who exercise may help inform strategies designed to increase walking among those who do not adhere to recommendations.

Ischemia-induced lower extremity neurologic impairment after fenestrated endovascular aneurysm repair

OBJECTIVE

Placement of large sheaths in the iliac system during fenestrated endovascular aneurysm repair (FEVAR) leads to lower extremity (LE) ischemia that can be associated with serious neurologic complications. We sought to determine the effect of LE ischemic time on neurologic impairment after FEVAR.

METHODS

Consecutive patients who underwent FEVAR at a single institution were analyzed. LE ischemic time was calculated from the time of large sheath (≥18F) insertion to the time of sheath removal from the iliac arteries that led to continuous LE ischemia. The primary outcome was neurologic impairment defined as any new sensory or motor deficit in either LE. Outcomes were analyzed using descriptive statistics and modeled with logistic regression with interaction terms. Each individual LE was used as a unit of analysis.

RESULTS

We examined 101 patients (202 lower extremities) who underwent FEVAR over a 5-year period. The median LE ischemic time was 2.75 hours (range, 0.8-5.2 hours). Neurologic impairment developed in 18 extremities (9%). Of those, 12 (67%) developed mild sensory loss, 6 (33%) complete sensory loss, 4 (22%) loss of proprioception, and 2 (11%) motor dysfunction. Sensory deficit was permanent in four limbs (2%) and motor dysfunction in one limb (0.5%). In all other cases, the neurologic examination returned to baseline by postoperative day 15. Duration of LE ischemic time (odds ratio, 6.3; 95% confidence interval, 3.1-12.4; P < .001) and common iliac artery (CIA) stenosis to a lumen of 8 mm or less (odds ratio, 2.7; 95% confidence interval, 1.5-7.3; P = .002) were independent predictors for the development of neurologic impairment. An interaction term between LE ischemic time and CIA stenosis was statistically significant (P = .042), indicating that the presence of CIA stenosis modifies the effect of LE ischemic time. In those with CIA stenosis to a lumen of 8 mm or less, the risk of neurologic impairment increased rapidly after 2.5 hours of LE ischemia, and became nearly certain after 4 hours of ischemic time. By contrast, patients without CIA stenosis tolerated longer ischemic times and demonstrated a less steep increase in the risk for LE neurologic impairment.

CONCLUSIONS

LE neurologic impairment after FEVAR is strongly associated with LE ischemic time and CIA occlusive disease to a lumen of 8 mm or less. Our data indicate that, when the LE ischemic time is expected to exceed 2.5 hours (in patients with CIA stenosis) or 3 hours (in patients without CIA stenosis), measures to ensure LE perfusion should be given consideration.

Successful Smoking Cessation Associated with Walking Behavior in Patients with Claudication

BACKGROUND

Behavioral economics theories suggest that a preference for delayed benefits promotes positive behavioral change, a concept relevant to both smoking cessation and community-based exercise regimens for claudication. Given the high rate of smoking among older veterans, we were interested in examining the association between smoking cessation, exercise regimen adherence, and preferences for delayed versus immediate benefits.

METHODS

Between April 2017 and March 2018, patients with claudication at the Michael E. DeBakey Veterans Affairs Medical Center in Houston, Texas, received questionnaires collecting information on social, behavioral, and psychological characteristics. A dual validation system, via the electronic medical record and survey data, measured the primary outcome-smoking cessation versus current smoking. Self-reported physical activity was measured through the validated Ainsworth's compendium of Physical Activities and binary survey questions. The Walking Impairment and Barratt's Impulsivity Questionnaires measured subjective symptom severity and behavioral economics factors, respectively. Multivariable, logistic regression models identified significant associations.

RESULTS

The survey was mailed to 500 patients who met the eligibility criteria. We received responses from 148 individuals (30%), and 67 of 141 (48%) indicated that they had successfully quit smoking. In unadjusted comparisons, the median cognitive complexity score in the smoking cessation group was higher than that in the current smoking group. A greater proportion of patients who reported walking for exercise (n = 46) also reported successful smoking cessation (28/46, 61%). Among those who were not walking for exercise (n = 88), more individuals reported current smoking (49/88, 56%). In the multivariable model, individuals who had successfully stopped smoking were older (odds ratio [OR]: 7.59, P < 0.001), more likely to walk for exercise (OR: 3.94, P = 0.009), more interested in the future than in the present (OR: 1.73, P = 0.030), and more likely to regularly save money (OR: 3.49, P = 0.046).

CONCLUSIONS

We found that participants who reported successful smoking cessation were more likely to report walking for exercise. Our findings suggest that adherence to walking may be less challenging for patients who have already successfully implemented and continue to implement another beneficial health behavior (smoking cessation). Patients with claudication who are current smokers may be less likely to adopt exercise recommendations.

Missing Data in Surgical Data Sets: A Review of Pertinent Issues and Solutions

Incomplete data is a common problem in research studies. Methods to address missing observations in a data set have been extensively researched and described. Disseminating these methods to the greater research community is an ongoing effort. In this article, we describe some of the basic principles of missing data and identify practical, commonly used methods of adjustment relevant to surgical data sets. Through an example data set, we compare models generated through complete case analysis, single imputation (SI), and multiple imputation (MI). We also provide information on the steps to conduct MI using Stata IC. In our comparisons, we found that differences in odds ratios were greatest between the results from complete case analysis compared to the SI and MI models indicating that in this case the reduction in statistical power has a non-negligible effect on the parameter estimates. Odds ratio estimates from the SI and MI methods were largely similar. In some instances, when compared to the MI method, the SI method tended to overestimate effect sizes. While in this example the differences in odds ratios do not vary greatly between the SI and MI methods, there are clear indications supporting the use of MI over SI. By describing the issues surrounding missing data and the available options for adjustment, we hope to encourage the use of robust imputation methods for missing observations.

Distal vein patch use and limb events after infragenicular prosthetic bypasses

OBJECTIVE

In the absence of suitable autologous vein, the use of prosthetic grafts for infragenicular bypasses in peripheral arterial disease has become standard practice. The purpose of this study was to investigate whether creating a vein patch at the distal anastomosis would further improve patency and freedom from major adverse limb events (MALEs). Furthermore, we sought to investigate whether the use of a distal vein patch (DVP) was associated with lower rates of acute limb ischemia (ALI) for those presenting with occluded prosthetic bypass graft.

METHODS

The cases of all patients undergoing infragenicular prosthetic bypass grafts between January 2009 and July 2016 were retrospectively reviewed. Demographics of the patients, clinical data, and outcomes (graft patency and MALEs) were collected. Patients were compared according to treatment group (DVP vs no DVP). A Cox regression analysis was used to analyze follow-up results.

RESULTS

During the study period, a total of 373 patients underwent infragenicular bypass at our institution; of those, 93 (24.9%) had prosthetic grafts (DVP, 39; no DVP, 54). Overall, 92 (98.9%) patients were male; the mean age was 63.3 ± 6.6 years and did not differ between the two groups. Patients undergoing prosthetic bypass with DVP were more likely to have chronic obstructive pulmonary disease (38.5% vs 14.8%; P = .009) and less likely to have chronic kidney disease (2.6% vs 20.4%; P = .011). Follow-up data were available for all patients for a median of 7.8 months (range, 1-89 months). After adjustment for differences in demographics and clinical data between the two groups, when outcomes were analyzed, MALEs were significantly lower in the DVP group (35.9% vs 57.4%; odds ratio [OR], 0.4; 95% confidence interval [CI], 0.2-0.9; P = .041). Similarly, reintervention rates were significantly lower in the DVP group (30.8% vs 50.0%; OR, 0.4; 95% CI, 0.2-0.9; P = .044). There was a trend toward higher primary patency in the DVP group (46.2% vs 35.2%; OR, 1.5; 95% CI, 0.7-3.5; P = .206) and lower rates of ALI after bypass occlusion (30.0% vs 42.9%; OR, 0.6; 95% CI, 0.2-1.8; P = .345). A Cox regression time-to-event analysis revealed late separation of freedom from MALEs for DVP relative to no DVP (log rank, P = .269).

CONCLUSIONS

In this evaluation of infragenicular prosthetic bypass grafts, the creation of a vein patch at the distal anastomosis was associated with lower reintervention rates and a trend toward improved primary patency and MALEs. Furthermore, for those presenting with occluded prosthetic bypass graft, the use of a DVP was associated with a trend toward lower rates of ALI.

A Multi-Component Strategy to Decrease Wound Complications after Open Infra-Inguinal Re-Vascularization

BACKGROUND

Wound complications remain a significant source of morbidity for patients undergoing open infra-inguinal re-vascularization. The purpose of this study was to determine the impact of several infection-control strategies on post-operative wound complications after open infra-inguinal re-vascularization.

METHODS

A retrospective cohort study was conducted among all patients who underwent an open infra-inguinal re-vascularization procedure before and after 2014. Since 2014, we have implemented strategies to reduce post-operative wound complications, including: (1) Decreasing the use of incisional skin staples, (2) increasing the use of negative pressure wound therapy (NPWT) dressings, and (3) implementing an outpatient elective decontamination protocol for methicillin-resistant Staphylococcus aureus. "Pre-era" is defined as the period between January 2012 and December 2013, before the implementation of infection control strategies; "Post-era" is between January 2015 and August 2016, after implementation. The primary outcome of interest is 30-day wound complications (infection or dehiscence). Multi-variable logistic regression analysis was used to identify significant predictors of wound-related complications between the two cohorts. Propensity score adjustment controlled for baseline patient characteristics, peri-operative variables, and surgeon experience.

RESULTS

A total of 338 open infra-inguinal procedures were performed: 175 in the pre-era and 163 in the post-era. Chlorhexidine skin preparation was used in the majority (321 [95%]) of cases. Comparing the periods, the post-era is characterized by a significant decrease in the use of groin staples (118 [67%] vs. 51 [31%], p < 0.001), and an increased application of NPWT dressings (6 [4%] vs. 66 [43%], p < 0.001). Thirty-five (37%) outpatient elective cases received the pre-operative decontamination protocol in the post-era. Compared with the pre-era, there was a decrease in the 30-day rate of wound complications (68 [39%] to 42 [26%], p = 0.011), and infection-related re-admissions (31 [17.7%] to 21 [12.9%], p = 0.220). When adjusting for patient characteristics, operative variables, and surgeon experience, post-era had significantly lower wound complications (odds ratio [OR] 0.33, p = 0.002) and re-operations (OR 0.16, p = 0.007). Among outpatient elective cases, the decontamination protocol was also independently associated with these two outcomes (wound complications: OR 0.05, p = 0.006; re-operations: 0.06, p = 0.002). The use of groin staples was an independent predictor of deep groin infections (OR 248, p < 0.001) and re-operations (OR 8.16, p = 0.032).

CONCLUSIONS

Wound complications after open infra-inguinal re-vascularization have decreased significantly after the implementation of several infection-control strategies. Findings suggest that skin staples should be avoided in groin wounds, and anti-staphylococcal decontamination protocols decrease wound complications and prevent re-operations.

The influence of pain-related beliefs on physical activity and health attitudes in patients with claudication: A pilot study

We examined how pain beliefs are related to symptom severity, expectations of risk/benefits, and baseline physical activity among claudicants. Eligible patients at the Michael E DeBakey Veterans Affairs Medical Center were administered questionnaires that measured: fear-avoidance beliefs (Fear-Avoidance Beliefs Questionnaire [FABQ]), walking impairment, baseline physical activity, claudication type, and risk/benefit attitudes. Among 20 participants, the median age was 69 years (IQR: 66–75). In our efforts to understand how fear-avoidance beliefs influenced physical activity among people with claudication, we found that 12 out of 19 participants (63%) thought that the primary etiology of their pain was walking, while 18 (out of 20) (90%) people thought that walking would exacerbate their leg symptoms – suggesting that there was some confusion regarding the effects of walking on claudication. Those who expected that walking would benefit their symptoms more than surgery reported fewer fear-avoidance beliefs ( p=0.01), but those who believed that walking would make their leg pain worse expected greater benefit from surgery ( p=0.02). As symptom severity increased, fear-avoidance beliefs also increased ( p=0.001). The association between symptom severity and fear-avoidance beliefs indicates that as pain or impairment increases, the likelihood of avoiding behaviors that are thought to cause pain might also increase. Accounting for pain-related beliefs when recommending physical activity for claudication should be considered.

Implications of Clinical Documentation (In)Accuracy: A Pilot Study Among General Surgery Residents

Accurate and reliable medical records are necessary for assessing, improving, and reimbursing healthcare services. Clear and concise physician documentation is essential to assuring accurate and reliable medical records. Yet, prior literature reveals surgery residents do not receive adequate, beneficial education on medical record documentation and coding. This is concerning because the evaluation of and reimbursement for healthcare service delivery relies on the physician's ability to produce appropriate medical records, which then get translated into billable codes. This pilot study suggests hospitals may incur significant financial loss in revenue due to inaccurate clinical documentation by residents. Thus, educational training for medical residents in the area of clinical documentation and hospital-specific coding practices may prove financially advantageous.

A model to estimate cost-savings in diabetic foot ulcer prevention efforts

BACKGROUND

Sustained efforts at preventing diabetic foot ulcers (DFUs) and subsequent leg amputations are sporadic in most health care systems despite the high costs associated with such complications. We sought to estimate effectiveness targets at which cost-savings (i.e. improved health outcomes at decreased total costs) might occur.

METHODS

A Markov model with probabilistic sensitivity analyses was used to simulate the five-year survival, incidence of foot complications, and total health care costs in a hypothetical population of 100,000 people with diabetes. Clinical event and cost estimates were obtained from previously-published trials and studies. A population without previous DFU but with 17% neuropathy and 11% peripheral artery disease (PAD) prevalence was assumed. Primary prevention (PP) was defined as reducing initial DFU incidence.

RESULTS

PP was more than 90% likely to provide cost-savings when annual prevention costs are less than $50/person and/or annual DFU incidence is reduced by at least 25%. Efforts directed at patients with diabetes who were at moderate or high risk for DFUs were very likely to provide cost-savings if DFU incidence was decreased by at least 10% and/or the cost was less than $150 per person per year.

CONCLUSIONS

Low-cost DFU primary prevention efforts producing even small decreases in DFU incidence may provide the best opportunity for cost-savings, especially if focused on patients with neuropathy and/or PAD. Mobile phone-based reminders, self-identification of risk factors (ex. Ipswich touch test), and written brochures may be among such low-cost interventions that should be investigated for cost-savings potential.

Ambulation and independence among Veterans with nontraumatic bilateral lower-limb loss

In describing functional outcomes and independent living in a cohort of bilateral major amputees, we sought to provide current estimates of function and independence after a second major amputation in an elderly Veteran population with peripheral arterial disease and/or diabetes. After retrospectively reviewing and excluding the electronic health records of those failing to meet the inclusion criteria, we identified 40 patients with a history of unilateral major amputation who underwent a second major amputation during the defined study period. Of these, 43% (17) were bilateral transfemoral amputations (TFAs); bilateral transtibial amputations (TTAs) and TFA-TTA accounted for the rest (33% and 25%, respectively). Of the 19 (48%) patients who were ambulatory prior to bilateral amputation, only 2 (11%) remained ambulatory after the second amputation, while 17 (89%) patients lost ambulatory capabilities. Compared with those who were </=65 yr, those between 66 and 79 yr were 18% less likely to ambulate precontralateral amputation (p = 0.03). All patients with bilateral TFA were nonambulatory. Independence postcontralateral amputation decreased from 88% (35) to 53% (21). When data were available (58%), pre and post Functional Independence Measure scores showed a decrease in 74% of patients, while 22% showed an increase. In conclusion, bilateral lower-limb amputation among dysvascular Veterans is highly associated with a loss of ambulation.

Carotid Artery Stenting with Distal Protection Using the Carotid Wallstent and Filterwire Neuroprotection: Single-Center Experience of 380 Cases with Midterm Outcomes

Emerging data have supported the clinical efficacy of carotid artery stenting (CAS) in stroke prevention in high-risk surgical patients. This study was performed to evaluate the midterm clinical outcome of CAS using the Carotid Wallstent and FilterWire distal protection (both Boston Scientific, Natick, MA) at an academic institution. Risk factors for in-stent restenosis (ISR) were also analyzed. Clinical variables and treatment outcome of high-risk patients who underwent Carotid Wallstent placement with FilterWire EX/EZ neuroprotection were analyzed during a recent 54-month period. Three hundred eighty CAS procedures were performed in 354 patients. Technical success was achieved in 372 cases (98%), and symptomatic lesions existed in 85 (24%) patients. No patient experienced periprocedural mortality or neuroprotective device–related complication. The 30-day stroke and death rate was 2.7%, and the overall complication rate was 6.9%. The overall major or fatal stroke rates in symptomatic and asymptomatic patients were 4.6% and 1.3%, respectively (not significant). The overall stroke and death rates between the symptomatic and asymptomatic groups were 5.8% and 2.4%, respectively (not significant). The median follow-up period was 29 months (range 1–53 months). With Kaplan-Meier analysis, the rates of freedom from 60% or greater ISR after CAS procedures at 12, 24, 36, and 48 months were 97%, 94%, 92%, and 90%, respectively. The rates of freedom from all fatal and nonfatal strokes at 12, 24, 36, and 48 months were 97%, 91%, 89%, and 85%, respectively. Multivariable analysis of significant univariate predictors identified that postendarterectomy stenosis (odds ratio [OR] 3.98, p = .02) and multiple stent placement (OR 3.68, p = .03) were independent predictors of ISR. Our study yielded favorable short-term and midterm clinical results using Carotid Wallstent with FilterWire neuroprotection. Late follow-up results showed low rates of fatal and nonfatal stroke and favorable ISR rates compared with other carotid stent trials. Postendarterectomy and multiple stent placement were associated with subsequent ISR.

Utility of Retrievable Vena Cava Filters and Mechanical Thrombectomy in the Endovascular Management of Acute Deep Venous Thrombosis

Endovascular interventions of symptomatic deep venous thrombosis (DVT) using various therapeutic modalities, such as thrombolysis, mechanical thrombectomy, and inferior vena cava (IVC) filter placement, have received increased focus owing in part to advances in catheter-based interventional technologies. Although systemic anticoagulation remains the primary treatment modality in DVT, catheter-based interventions can provide rapid removal of large thrombus burden and possibly preserve venous valvular function in patients with symptomatic DVT. This article reviews current endovascular treatment strategies for acute DVT. Specifically, the utility of mechanical thrombectomy along with various temporary IVC filters in the setting of DVT is examined. Lastly, an illustrative case of acute DVT that was treated with endovascular intervention with IVC filter placement is presented.

Department of Veterans Affairs Cooperative Studies Program Network of Dedicated Enrollment Sites: Implications for Surgical Trials

IMPORTANCE

Surgical clinical trials have played a critical role in shaping clinical practice, yet their launch and conduct remain challenging. Innovative approaches to carrying out such studies can not only help transform how trials produce definitive evidence but also move the field toward increased participation in trials.

OBJECTIVE

To review a recently launched pilot program aimed at enhancing patient enrollment and improving surgical trial operations at individual sites and nationally.

SETTING AND PARTICIPANTS

After a solicitation to create a national network focused on making the conduct of clinical trials more efficient, 10 Department of Veterans Affairs (VA) sites were selected. These sites, collectively called the Cooperative Studies Program (CSP) Network of Dedicated Enrollment Sites (NODES), were evaluated with regard to their previous participation in CSP multisite trials, the strength of the local clinical research environment, and presentation of innovative plans to coordinate and enhance the operations of local CSP studies and share best practices with other centers. Node accountability was also emphasized and involved metrics that tracked productivity and efficiency.

RESULTS

Building from available CSP experience in a range of clinical trials, including ones involving surgical interventions, NODES provides VA surgeons with resources for facilitating timely study initiation, determining patient availability, and addressing enrollment barriers. Such resources are particularly important for surgical studies, which often face challenges in patient recruitment and retention. In addition, NODES can maintain qualified and trained personnel at sites to support surgeons with limited time to fulfill the numerous administrative and regulatory responsibilities that often fall to the investigators.

CONCLUSIONS AND RELEVANCE

The VA's approach to enhancing trial efficiency may reinvigorate interest in surgical trials by offering a redesigned cooperative framework that builds on a core of high-yield sites and could mitigate traditional limitations of surgical trials.

Use of simulation to assess a statistically driven surgical scheduling system

BACKGROUND

To maximize operating room (OR) utilization, better estimates of case duration lengths are needed. We used computerized simulation to determine whether scheduling OR cases using a statistically driven system that incorporates patient and surgery-specific factors in the process of case duration prediction improves OR throughput and utilization.

METHODS

We modeled surgical and anesthetic length of vascular surgical procedures as a function of patient and operative characteristics using a multivariate linear regression approach (Predictive Modeling System [PMS]). Mean historical operative time per surgeon (HMS) and mean anesthetic time were also calculated for each procedure type. A computerized simulation of scheduling in a single OR performing vascular operations was then created using either the PMS or the HMS.

RESULTS

Compared to HMS, scheduling the operating room using the PMS increased throughput by a minimum of 15% (99.8% cumulative probability, P < 0.001). The PMS was slightly more likely to lead to overtime (mean 13% versus 11% of operative days during a calendar year, P < 0.001). However, the overtime lasted longer in the HMS group (mean 140 versus 95 min per day of overtime, P < 0.001). PMS was associated with lower OR underutilization rate (mean 23% versus 34% of operative days, P < 0.001) and less lengthy OR underutilization (mean 120 versus 193 min per day of underutilization, P < 0.001).

CONCLUSIONS

This computerized simulation demonstrates that using the PMS for scheduling in a single operating room increases throughput and other measures of surgical efficiency.