To Resect or Not to Resect: A Nationwide Comparison of Management of Sigmoid Volvulus.

INTRODUCTION: Despite the high recurrence rate of sigmoid volvulus, there is reluctance to perform a prophylactic colectomy in frail patients due to the operation's perceived risks. We used a nationally representative database to compare risk of recurrence in patients undergoing a prophylactic colectomy versus endoscopic detorsion alone. METHODS: We performed a retrospective cohort study using the National Readmission Database (2016-2019) including patients aged ≥18 y who had an emergent admission for sigmoid volvulus and underwent endoscopic detorsion on the day of admission. We performed a 1:1 propensity matching adjusting for patient demographics, frailty score comprising of 109 components, and hospital characteristics. Our primary outcome was readmission due to colonic volvulus and secondary outcomes included mortality, complications, length of stay (LOS), and costs during index admission and readmission. We performed a subgroup analysis in patients with Hospital Frailty Score >5. RESULTS: We included 2113 patients of which 1046 patients (49.5%) underwent a colectomy during the initial admission. In the matched population of 830 pairs, readmission due to colonic volvulus was significantly lower in patients undergoing endoscopy followed by colectomy than endoscopy alone. Patients undergoing a colectomy had higher gastric and renal complications, longer LOS, and higher costs but no difference in mortality. In the subgroup analysis of frail patients, readmission was significantly lower in patients with prophylactic colectomy with no significant difference in mortality in 439 matched patients. CONCLUSIONS: Prophylactic colectomy was associated with lower readmission, a higher rate of complications, increased LOS, and higher costs compared to sigmoid decompression alone.

Development of a Predictive Nomogram for Circumferential Resection Margin in Rectal Cancer Surgery.

INTRODUCTION: Circumferential resection margin (CRM) is a key quality metric and predictor of oncologic outcomes and overall survival following surgery for rectal cancer. We aimed to develop a nomogram to identify patients at risk for a positive CRM in the preoperative setting. METHODS: We performed a retrospective evaluation of the National Cancer Database from 2010 to 2014 for patients with clinical stage I-III rectal cancer who underwent total mesorectal excision. Patients were excluded for emergency operation, resection for cancer recurrence, palliative resection, transanal resection, and missing CRM status. The primary outcome was positive CRM. Secondary outcomes included overall survival. RESULTS: There were 28,790 patients included. 2245 (7.8%) had a positive CRM. Higher tumor grade, lack of neoadjuvant chemotherapy, mucinous/signet tumor histology, open approach, abdominoperineal resection, higher T stage, lymphovascular invasion, and perineural invasion were all significantly associated with positive CRM (P < 0.05) and were included in the nomogram. The C-statistic was 0.703, suggesting a good predictive model. CONCLUSIONS: Positive CRM is associated with specific patient demographics and tumor characteristics. These factors can be used along with preoperative MRI to predict CRM positivity in the preoperative period and plan accordingly.

Anastomotic Considerations in Diverticulitis.

Diverticulitis is a common indication for colorectal surgery, both in the acute and the elective setting. The anastomosis between the colon and rectum is a critical component of colectomy for diverticular disease and should be approached thoughtfully. This article reviews important surgical considerations when creating a colorectal anastomosis in the setting of diverticular disease, whether following the reversal of an end colostomy, during an acute episode of diverticulitis, or electively for chronic or complicated disease. Timing of surgery and preoperative assessment, minimally invasive approaches, and intraoperative maneuvers and considerations are discussed.

Peer Assessment in Medical Student Education: A Study of Feasibility, Benefit, and Worth.

BACKGROUND: Direct experience with medical procedures is an important component of medical school training, yet opportunities for medical students have dwindled for various reasons. To offset this, simulated procedures are being integrated into training. However, this comes with additional time commitments required of teaching surgeons regarding assessment of simulation. A solution to this could be peer assessment. We hypothesize that there will be no significant difference between peer assessment when compared to that of a teaching surgeon. METHODS: Third-year medical students were shown 3 simulated procedures by teaching surgeon and provided a grading rubric. Student performances were independently graded by peer assessment and by teaching surgeons. All peer assessment grades and surgeon grades were compared. RESULTS: Four hundred fifty-nine medical students completed the simulation procedures. Comparisons between the teaching surgeons and peer assessment evaluations demonstrated a 99% interobserver agreement for pass-fail designation and 98% agreement for individual data points (kappa = .78). Survey results demonstrated a significant increase in confidence in performing the tested items and comfort with peer assessment. DISCUSSION: This analysis demonstrates that the inclusion of peer assessment within medical school is highly comparable to teaching surgeon assessments.

Modified Frailty Index Predicts Postoperative Outcomes in Patients Undergoing Radical Pelvic Surgery.

Patients undergoing radical pelvic surgery such as proctectomy or radical cystectomy are at risk of experiencing a variety of complications. Frailty renders patients vulnerable to adverse events. We hypothesize that frailty measured preoperatively using a validated scoring system correlates with increased likelihood of experiencing Clavien-Dindo grade IV complications and 30-day mortality and may be used as a predictive model for patients preoperatively. The NSQIP database was queried for patients who underwent proctectomy or radical cystectomy from 2008 to 2012. Preoperative frailty was calculated using the 11-point modified frailty index (MFI). Patients were scored based on the presence of indicators and categorized into two groups (<3 or ≥3). Major postoperative morbidities and mortality were identified and analyzed in each group. 10,048 proctectomy and cystectomy patients were identified. The MFI was found to be predictive of both 30-day mortality (P < 0.0001) and Clavien-Dindo grade IV complications (P < 0.0001). Receiver operating characteristic analysis demonstrated improved discriminative power of the MFI with the addition of American Society of Anesthesiologists class for both prediction of complications and 30-day mortality. An MFI score of ≥3 is predictive of postoperative morbidity and mortality. Providers should be encouraged to calculate frailty preoperatively to predict adverse outcomes.

CDCP1 enhances Wnt signaling in colorectal cancer promoting nuclear localization of ß-catenin and E-cadherin.

Elevated CUB-domain containing protein 1 (CDCP1) is predictive of colorectal cancer (CRC) recurrence and poor patient survival. While CDCP1 expression identifies stem cell populations that mediate lung metastasis, mechanisms underlying the role of this cell surface receptor in CRC have not been defined. We sought to identify CDCP1 regulated processes in CRC using stem cell populations, enriched from primary cells and cell lines, in extensive in vitro and in vivo assays. These experiments, demonstrating that CDCP1 is functionally important in CRC tumor initiation, growth and metastasis, identified CDCP1 as a positive regulator of Wnt signaling. Detailed cell fractionation, immunoprecipitation, microscopy, and immunohistochemical analyses demonstrated that CDCP1 promotes translocation of the key regulators of Wnt signaling, ß-catenin, and E-cadherin, to the nucleus. Of functional importance, disruption of CDCP1 reduces nuclear localized, chromatin-associated ß-catenin and nuclear localized E-cadherin, increases sequestration of these proteins in cell membranes, disrupts regulation of CRC promoting genes, and reduces CRC tumor burden. Thus, disruption of CDCP1 perturbs pro-cancerous Wnt signaling including nuclear localization of ß-catenin and E-cadherin.

Current U.S. Pre-Operative Bowel Preparation Trends: A 2018 Survey of the American Society of Colon and Rectal Surgeons Members.

Background: The effect of an oral antibiotic preparation prior to colorectal surgery was first examined and exalted in the 1973 paper by Nichols et al. Since this commencement, enthusiasm for the oral antibiotic regimen has waxed and waned reflecting the literature focused on this topic over the past 40 years. Polling colorectal surgeons of define current practices has been performed at intervals throughout the years and has demonstrated a trend to decline in the practice. The most recent publication surveying U.S. practices was in 2010, which reported a minority, 36%, use of oral antibiotics prior to elective colorectal surgery; a marked downtrend from the 88% use described in 1990. Since this last survey, the colorectal surgery community has performed considerable research examining the benefit of oral antibiotic and mechanical bowel preparation. This manuscript evaluates the current use of oral antibiotics in colorectal surgery in the U.S. and how practice trends have developed in response to current recommendations in the literature. Methods: An electronic survey was created and distributed to U.S. colorectal surgeons to evaluate current opinions and practice trends. A total of 359 American Society of Colon and Rectal Surgeons members responded. A review of the recent literature pertaining to pre-operative bowel practices and outcomes was performed to compare with current practices. Results: A significant majority (83.2%) of respondents use pre-operative oral antibiotics routinely, and 98.6% routinely use mechanical bowel preparation. The use of a combination of parenteral antibiotics, oral antibiotics, and mechanical bowel preparation is reported by 79.3%. The most commonly employed oral antibiotic regimen is neomycin and metronidazole. The most common mechanical bowel preparation is polyethylene glycol (PEG). The most common parenteral antibiotics are cefazolin and metronidazole. There was no statistically significant difference in this practice by geographic region, Board-certified status, or practice setting. Conclusion: The majority of colorectal surgeons employ a combination of oral antibiotics, mechanical bowel preparation, and parenteral antibiotics prior to colorectal surgery. This is consistent across geographic regions, despite Board certification status or practice setting, and is reflective of the recommendations based on recent literature.

Permanent mesh results in long-term symptom improvement and patient satisfaction without increasing adverse outcomes in hiatal hernia repair.

BACKGROUND: The purpose of this study is to evaluate symptom relief, patient satisfaction, and safety of permanent mesh following Nissen fundoplication and hiatal hernia repair. METHODS: Patients who underwent Nissen fundoplication and hiatal hernia repair with permanent mesh (Crurasoft; Davol, Inc, Bard, Warwick, RI) between 2005 and 2011 were identified. A retrospective chart review was conducted. Long-term follow-up data were obtained via telephone interviews using a modified 5-point Likert scale. RESULTS: Forty-one patients were identified. Twenty-six patients (63%) had complete follow-up data. Mean follow-up period was 65 months (14 to 96 months). Symptomatic improvement occurred in 23 patients (88%). Twenty-three patients (88%) reported overall satisfaction with the procedure as either excellent or good, and 23 of 26 patients (89%) would undergo surgery again. Three patients (12%) reported hernia recurrence. There were no mesh erosions. CONCLUSION: The use of permanent (Crurasoft; Davol, Inc) mesh resulted in symptom improvement as well as patient satisfaction, and no mesh erosions were seen.

Cannabinoid subtype-2 receptors modulate the antihyperalgesic effect of WIN 55,212-2 in rats with neuropathic spinal cord injury pain.

BACKGROUND CONTEXT: There is increasing evidence for a role of the cannabinoid (CB) system in the development of neuropathic pain (NP) after spinal cord injury (SCI). The nonspecific CB1 and CB2 receptor agonists, WIN 55, 212-2 (WIN), have previously been shown to alleviate both mechanical and thermal hyperalgesia (TH) after peripheral nerve injury. PURPOSE: The present study was designed to identify the CB receptors involved in the antihyperalgesic effect of WIN by using selective antagonists for CB1 and CB2 receptors. STUDY DESIGN: This is an in vivo and behavioral study using a moderate T9 contusion SCI. After injury, TH of the hind paws was measured on postinjury days 21 through 42. METHODS: Sprague-Dawley rats underwent a contusion SCI using the Multicenter Animal Spinal Cord Injury Study (MASCIS) weight-drop impactor, which induced a moderate T9 SCI. Only animals showing consistent plantar stepping and consistent forelimb and hind limb coordination (Basso, Beattie, and Bresnahan score=15) were tested for TH. Animals exhibiting decreased withdrawal latency time, indicating TH, on or before Day 42, were selected for pharmacological intervention. Animals not exhibiting TH did not receive pharmacological intervention and were sacrificed. Rats underwent hind paw testing before any drug administration (after injury), 45 minutes after selective CB antagonist (AM 251 or AM 630) administration (postantagonist) and again 45 minutes after WIN administration (post-WIN). There were a total of seven treatment groups: saline vehicle control; Dimethyl sulfoxide (DMSO) vehicle control; low-dose WIN (0.2 mg/kg); and high-dose WIN (2.0 mg/kg); AM 251 (3 mg/kg) and AM 630 (1 mg/kg) were given subcutaneously in a total volume of 0.5 mL. Followed by intraperitoneal injection of WIN after each antagonist, sham-operated rats repeated pharmacological intervention used with treatment Groups 5 and 6. RESULTS: Thermal hyperalgesia was significantly ameliorated in a dose-dependent manner with systemically administered WIN. Cannabinoid receptor Type 1 antagonist AM 251 pretreatment did not affect the antihyperalgesic effect of WIN. By contrast, pretreatment with the CB2 receptor antagonist AM 630 significantly attenuated the effect of WIN. CONCLUSION: Taken together, these results suggest a role of the CB2 receptor in modulating SCI-induced TH. Selective activation of the CB2 receptor could potentially lead to analgesic effects on NP while avoiding psychotropic side effects in patients with SCI.

Antihyperalgesic effects of vanilloid-1 and bradykinin-1 receptor antagonists following spinal cord injury in rats.

OBJECT: The authors previously discovered that genes for the bradykinin-1 (B1) receptor and the transient receptor potential vanilloid subtype 1 (TRPV1) were overexpressed in animals exhibiting thermal hyperalgesia (TH) following spinal cord injury (SCI). They now report the effect of TRPV1 (AMG9810) and B1 (Lys-[Des-Arg9,Leu8]-bradykinin) antagonists on TH in animals following SCI. METHODS: The rats were subjected to contusion SCI and then divided into groups in which TH did or did not develop. The animals from both groups were given either AMG9810, Lys-(Des-Arg9,Leu8)-bradykinin, or the drug-specific vehicle (control groups). Animals were tested for TH preinjury and at regular intervals after SCI by using the hindlimb withdrawal latency test. CONCLUSIONS: The administration of AMG9810 likely improves TH as a result of a generalized analgesic effect, whereas the effect of Lys-(Des-Arg9,Leu8)-bradykinin appears more specific to the reversal of TH. This information has potential usefulness in the development of treatment strategies for post-SCI neuropathic pain.