Penn Evidence-Based Literature Review (PEBLR)

Summarized highlights from contemporary literature in surgical and allied disciplines for general surgery residents.

Vascular & Cardiothoracic Surgery

Endovascular versus open repair of abdominal aortic aneurysm in 15-years' follow-up of the UK endovascular aneurysm repair trial 1 (EVAR trial 1): a randomised controlled trial
Patel R. et al., Lancet 2016 Oct 12
Contributor: Jon Quatromoni

Brief Summary

Synopsis:Multiple randomized trials have demonstrated an early survival benefit, albeit limited to a few years, for endovascular aneurysm repair (EVAR) compared to open repair of abdominal aortic aneurysms (AAA). It is unknown whether either intervention is better for long-term (>10 year) survival. This trial is an extension of EVAR trial 1, which originally randomized 1252 patients, fit for either intervention, to EVAR vs open repair between 1999 and 2004. The primary aim was to report the long-term results (up to 15 years) in terms of aneurysm-related and total mortality. Beyond 8 years of follow-up, open repair had a significantly lower total mortality (HR 1.25, p=0.048) and aneurysm-related mortality (HR 5.82, p<0.01). The increased aneurysm-related mortality in the EVAR group was attributable to secondary aortic sac rupture (13 deaths [7%] EVAR vs. 2 deaths [1%] in open repair), which also contributed to higher total mortality. Over the complete follow-up period, however, the mean total mortality and aneurysm-related mortality were not significantly different between groups. The rate of re-interventions was higher in the EVAR group at all timepoints. The authors concluded that despite the well-established early survival benefit of EVAR, the inferior late survival benefit and durability compared to open repair warrants lifelong surveillance to monitor sac size and timely re-intervention to correct underlying causes of expansion when necessary. Limitations of this study include the use of stent graft devices, pre-operative CT imaging and fluoroscopy (to establish size and placement of endografts), considered outdated by today’s standards. Stent grafts since then have undergone multiple iterations that address challenging proximal aortic neck anatomy, device migration, fabric fatigue, and branched designs for maintaining visceral perfusion. The corollary is that experience with open repair has simultaneously been decreasing, which may have the opposite effect on outcomes moving forward. Lastly, open repair patients had less diligent follow-up in this study, which may have led to an underestimation of aneurysm-related mortality as well as re-interventions, but may not have impacted total mortality. 

Quality Improvement, Health Services Research, Surgical Education

Are Patient-Reported Outcomes Correlated with Clinical Outcomes after Surgery? A Population-based Study
Waljee J.F., et al., Annals of Surgery 2016 October
Contributor: Rebecca L. Hoffman

Brief Summary

Synopsis: For surgical procedures in which measurable outcomes like morbidity and mortality are rare (bariatric, lap chole, hernia repairs), patient-reported outcomes (PROs) may be more useful for assessing quality. This study was a retrospective cohort study using data from the Michigan Bariatric Surgical Collaborative (MBSC). Patients underwnet a primary bariatric procedure between 1/1/2008 and 12/31/2012, and as part of the MBSC, filled out 2 measures of health-realted quality of life (HRQOL). Short term (30-day) and long-term (1 year) clinical outcomes were correlated with HRQOL. PROs had little correlation with complication rates, while they were correlated with percentage weight loss and hospital. When examining the proportion of variation in PROs accounted for by demographics, surgical procedure and clinical outcomes, there is between 15-44% that is left unaccounted for, suggesting there are still unmeasured quality factors. A major limitation of this study is that only one-year outcomes are captured, whereas complications like marginal ulcers, for instance, which can have a significant impact on QOL and occur later, are not captured. Also, only 32% of patients completed the HRQOL measures, allowing for a potential selection bias. 

General Surgery/MIS/Bariatrics, Colorectal Surgery

Early Versus Delayed Cholecystectomy for Acute Cholecystitis, Are the 72 hours Still the Rule? A Randomized Trial
Roulin D., et al. Annals of Surgery 2016 Nov
Contributor: Brett L. Ecker

Brief Summary

Synopsis: According to the Tokyo guidelines, the surgical management of acute uncomplicated cholecystitis with symptom duration >72 hours should be delayed for concern for increased intraoperative complications; yet, there are no prospective data to guide patient care in this particular scenario. A single center, prospective randomized trial of adult patients with at least 3 days of symptoms (median 4 [IQR 3-7] days) were randomized to early laparoscopic cholecystectomy (ELC) or delayed laparoscopic cholecystectomy (DLC) – consisting of antibiotics and outpatient evaluation for surgery at 6 weeks. ELC was performed in 41 patients with a low rate of complications (bile duct injury: 0.0%; conversion to open: 2.4%) and equivalent operative time to delayed, elective surgery. DLC was associated with treatment failure during initial hospitalization (6.8%) and readmission prior to surgery (24.4%), as well as increased medical costs. While the authors appropriately conclude that ELC is safe, the unconventional management of the delayed group (namely, a. omission of percutaneous cholecystostomy, and b. use of oral augmentin as primary antibiotic) limits meaningful comparisons between study arms.  

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