Feasibility of transanal total mesorectal excision (taTME) using the Medrobotics Flex® System.

BACKGROUND: The use of transanal total mesorectal excision (taTME) for treatment of rectal cancer is growing, but anatomic constraints prevent access to the proximal rectum with rigid instruments. The articulated instrumentation of current surgical robots is promising in overcoming these limitations, but the bulky size of current platforms inhibits the proximal reach of dissection. Flexible robotic systems could overcome these constraints while maintaining a stable platform for dissection. The goal of this study was to evaluate feasibility of performing taTME using the semi-robotic Flex® System (Medrobotics Corp., Raynham, MA) in human cadavers. METHODS: taTME was performed by two surgeons in six fresh human cadaveric specimens using the Flex® System, with or without transabdominal laparoscopic assistance. Both mid- and low-rectal lesions were simulated. Metrics including quality of visualization, maintenance of pneumorectum, maneuverability of instruments, effectiveness of pursestring suture placement, and dissection in an anatomically correct plane were evaluated. RESULTS: The semi-robotic endoluminal platform allowed for excellent visualization, insufflation, and dissection during taTME. Adequate pursestring occlusion of the rectum was achieved in all six cases. In cadavers with simulated mid-rectal lesions (N = 4), dissection and anterior peritoneal entry was achieved in all cases, with abdominal assistance utilized in two of four cases. In cadavers with simulated low-rectal lesions (N = 2), dissection was incomplete and aborted due to difficulty maneuvering instruments in close proximity to the rigid transanal port. CONCLUSIONS: Use of the Flex® system for taTME is feasible for mid-rectal dissection. Advantages over the traditional multi-armed robot include longer reach of instruments with the ability to dissect up to 17 cm from the anal verge, as well as tactile feedback. The current design of the flexible platform does not permit safe dissection in the distal rectum, although this constraint may be resolved with future adjustments to the equipment.

Lymphovascular Invasion and Perineural Invasion Negatively Impact Overall Survival for Stage II Adenocarcinoma of the Colon.

BACKGROUND: Lymphovascular invasion and perineural invasion are histopathological features associated with higher-risk colon cancer. OBJECTIVE: The purpose of this study was to quantify the impact of lymphovascular and perineural invasion on overall survival after diagnosis and to determine the protective effect of adjuvant chemotherapy for early adenocarcinoma with high-risk factors. DESIGN: This was a retrospective database review of the 2010-2014 National Cancer Database for colon cancer. SETTINGS: Individuals diagnosed with invasive adenocarcinoma of the colon (histology code 8140) with primary surgical resection with >12 nodes harvested and no positive nodes on pathological examination were included. PATIENTS: A total of 32,493 patients underwent surgical resection for stage II adenocarcinoma of the colon. INTERVENTIONS: The study involved multivariate Cox regression analysis of the impact of lymphovascular and perineural invasion and adjuvant chemotherapy on overall survival after a diagnosis of stage II adenocarcinoma of the colon. MAIN OUTCOME MEASURES: Survival after a diagnosis of stage II adenocarcinoma of the colon was measured. RESULTS: Five-year survival after diagnosis and surgical resection without adjuvant chemotherapy was lower for patients with lymphovascular (60.0%), perineural (56.9%), and lymphovascular and perineural invasion (55.8%) compared with double-negative disease (66.1%). Log-rank testing confirmed that adjuvant chemotherapy improved 5-year survival after diagnosis for lymphovascular (85.5%), perineural (83.6%), and lymphovascular and perineural invasion (74.3%). After controlling for differences in cohorts, Cox regression analysis showed an increased HR for mortality of 14.0% for lymphovascular (HR = 1.141 (95% CI, 1.060-1.228)), 32.1% for perineural (HR = 1.321 (95% CI, 1.176-1.483)), and 41.0% for lymphovascular and perineural invasion (HR = 1.409 (95% CI, 1.231-1.612)) compared with having neither. Chemotherapy showed a 43% reduction in hazard for mortality (HR = 0.570 (95% CI, 0.513-0.633)). LIMITATIONS: The study was limited by its retrospective review and observational bias. CONCLUSIONS: Lymphovascular and perineural invasion have a detrimental effect on survival after diagnosis of stage II adenocarcinoma of the colon. Chemotherapy may be protective specifically when lymphovascular and perineural invasion are present. See Video Abstract at http://links.lww.com/DCR/A786.

Elective Stoma Reversal Has a Higher Incidence of Postoperative Clostridium Difficile Infection Compared With Elective Colectomy: An Analysis Using the American College of Surgeons National Surgical Quality Improvement Program and Targeted Colectomy Databases.

BACKGROUND: Clostridium difficile infection is caused by the proliferation of a gram-positive anaerobic bacteria after medical or surgical intervention and can result in toxic complications, emergent surgery, and death. OBJECTIVE: This analysis evaluates the incidence of C difficile infection in elective restoration of intestinal continuity compared with elective colon resection. DESIGN: This was a retrospective database review of the 2015 American College of Surgeons National Surgical Quality Improvement Project and targeted colectomy database. SETTINGS: The intervention cohort was defined as the primary Current Procedural Terminology codes for ileostomy/colostomy reversal (44227, 44620, 44625, and 44626) and International Classification of Diseases codes for ileostomy/colostomy status (VV44.2, VV44.3, VV55.2, VV55.3, Z93.2, Z93.3, Z43.3, and Z43.2). PATIENTS: A total of 2235 patients underwent elective stoma reversal compared with 10403 patients who underwent elective colon resection. INTERVENTION: Multivariate regression modeling of the impact of stoma reversal on postoperative C difficile infection risk was used as the study intervention. MAIN OUTCOME MEASURES: The incidence of C difficile infection in the 30 days after surgery was measured. RESULTS: The incidence of C difficile infection in the 30-day postoperative period was significantly higher (3.04% vs 1.25%; p < 0.001) in patients undergoing stoma reversal. After controlling for differences in cohorts, regression analysis suggested that stoma reversal (OR = 2.701 (95% CI, 1.966-3.711); p < 0.001), smoking (OR = 1.520 (95% CI, 1.063-2.174); p = 0.022), steroids (OR = 1.677 (95% CI, 1.005-2.779); p = 0.048), and disseminated cancer (OR = 2.312 (95% CI, 1.437-3.719); p = 0.001) were associated with C difficile infection incidence in the 30-day postoperative period. LIMITATIONS: The study was limited because it was a retrospective database review with observational bias. CONCLUSIONS: Patients who undergo elective stoma reversal have a higher incidence of postoperative C difficile infection compared with patients who undergo an elective colectomy. Given the impact of postoperative C difficile infection, a heightened sense of suspicion should be given to symptomatic patients after stoma reversal. See at Video Abstract at http://links.lww.com/DCR/A553.

Laparoscopic versus open ventral hernia repair in patients with chronic liver disease.

BACKGROUND: Previous studies demonstrated laparoscopic ventral hernia repair (LVHR) to be associated with fewer short-term complications than open ventral hernia repair (OVHR). Little literature is available comparing LVHR and OVHR in chronic liver disease (CLD) patients. METHODS: Patients with model for end-stage liver disease score ≥9 who underwent elective ventral hernia repair in the National Surgical Quality Improvement Program Database were included. 30-day outcomes were compared between LVHR and OVHR after adjusting for hernia disease severity, baseline comorbidities and demographic factors. RESULTS: A total of 3594 ventral hernia repairs were included, 536 (14.9 %) of which were LVHR. After adjusting for other confounders, LVHR was associated with a lower incidence of wound-related complications (0.23, 95 % CI 0.07-0.74, p = 0.01), shorter length of stay (mean 3.7 vs. 5.0 days, p < 0.01) than OVHR, but similar systemic complications (p = 0.77), bleeding complications (p = 0.69), unplanned reoperation (p = 0.74) or readmission (p = 0.40). Propensity score-matched comparison showed similar conclusions. Five hundred and sixty-two patients had ascites, among whom 35 (6.2 %) underwent LVHR. In this subcohort, LVHR was associated with higher mortality (OR 5.36, 95 % CI 1.00-28.60, p = 0.05), systemic complications (OR 7.03, 95 % CI 2.06-24.00, p < 0.01), and unplanned reoperation (OR 6.03, 95 % CI 1.51-24.12, p = 0.01) than OVHR. CONCLUSIONS: In comparison with OVHR, LVHR is associated with similar short-term outcomes except for lower wound-related complications and shorter length of stay in CLD patients. However, when patients have ascites, LVHR is associated with higher mortality, systemic complications, and unplanned reoperation.

Efficacy of Distal Perfusion Cannulae in Preventing Limb Ischemia During Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis.

To date, no consensus exists regarding indication, technique, or efficacy of distal perfusion cannulae (DPC) in preventing limb ischemia among patients receiving venoarterial extracorporeal membrane oxygenation (VA-ECMO). We aim to examine the available literature and report association between DPC and risk of limb ischemia. PubMed/Medline, Scopus, Cochrane Central Register of Controlled Trials, Google Scholar, and bibliographies of included studies were searched from database inception until August 2016. Original studies describing the DPC placement technique and incidence of limb ischemia following DPC placement among VA-ECMO patients were included for systematic review. Studies with a comparison group of patients without DPC were included for meta-analysis. Two authors independently screened title/abstracts, reviewed full texts, and extracted data from the eligible studies. Meta-analysis was performed using the Mantel-Haenszel method under a random-effects model. Statistical heterogeneity was examined with the I2 statistic (RevMan Version 5.3). Of 542 title/abstracts screened, 62 full text articles were selected for review, yielding 22 retrospective observational studies, for a total of 779 patients with 132 limb ischemia events. There was significant variation in DPC indication, cannula type, and placement technique among the studies. Compared to no DPC, the presence of a DPC was associated with at least a 15.7% absolute reduction in the incidence of limb ischemia (9.74 vs. 25.42%; risk ratio 0.41; 95% confidence interval 0.26-0.65, P < 0.01; heterogeneity statistic I2 = 28%). There was no statistically significant difference in mortality in the pooled dataset comparing DPC versus no DPC. In adults treated with VA-ECMO, DPC placement was associated with a lower incidence of limb ischemia. Currently no consensus guidelines exist regarding indication for DPC placement. Given the association described in this analysis, future prospective trials are warranted to establish a causal relationship and optimal technique for the use of DPC in patients treated with VA-ECMO.

Biochemical properties of tissue-engineered cartilage.

OBJECTIVE: Microtia is treated with rib cartilage sculpting and staged procedures; though aesthetically pleasing, these constructs lack native ear flexibility. Tissue-engineered (TE) elastic cartilage may bridge this gap; however, TE cartilage implants lead to hypertrophic changes with calcification and loss of flexibility. Retaining flexibility in TE cartilage must focus on increased elastin, maintained collagen II, decreased collagen X, with prevention of calcification. This study compares biochemical properties of human cartilage to TE cartilage from umbilical cord mesenchymal stem cells (UCMSCs). Our goal is to establish a baseline for clinically useful TE cartilage. METHODS: Discarded cartilage from conchal bowl, microtic ears, preauricular tags, rib, and TE cartilage were evaluated for collagen I, II, X, calcium, glycosaminoglycans, elastin, and fibrillin I and III. Human UCMSCs were chondroinduced on 2D surfaces and 3D D,L-lactide-co-glycolic acid (PLGA) fibers. RESULTS: Cartilage samples demonstrated similar staining for collagens I, II, and X, elastin, and fibrillin I and III, but differed from rib. TE pellets and PLGA-supported cartilage were similar to auricular samples in elastin and fibrillin I staining. TE samples were exclusively stained for fibrillin III. Only microtic samples demonstrated calcium staining. CONCLUSIONS: TE cartilage expressed similar levels of elastin, fibrillin I, and collagens I and X when compared to native cartilage. Microtic cartilage demonstrated elevated calcium, suggesting this abnormal tissue may not be a viable cell source for TE cartilage. TE cartilage appears to recapitulate the embryonic development of fibrillin III, which is not expressed in adult tissue, possibly providing a strategy to control TE elastic cartilage phenotype.

Effects of connective tissue growth factor on the regulation of elastogenesis in human umbilical cord-derived mesenchymal stem cells.

BACKGROUND: A key to clinical microtia reconstruction is construct flexibility. The most significant current limitation to engineered elastic cartilage is maintaining an elastic phenotype, which is principally dependent on elastin production (although other parameters, including maintenance of a ratio above 1 for collagens II to I, minimizing collagen X content, and presence of adequate matrix fibrillin for elastin binding, all play supporting roles). Connective tissue growth factor (CTGF), a compound secreted by chondrocytes, has been shown to promote an elastic phenotype in mature rabbit chondrocytes; however, CTGF effect on undifferentiated mesenchymal stem cells (MSCs) has not been characterized. The principal aim of this study is to analyze CTGF effect on elastin production in umbilical cord (UC)-derived MSCs and to determine optimal timing of treatment to maximize elastin production. METHODS: Human UCMSCs (hUCMSCs) were isolated from Wharton jelly using an explant technique, grown to passage 3, seeded onto nanofiber scaffolds, and chondroinduced for 21 days. Nanofiber scaffolds were electrospun using solubilized poly L-lactide/D-lactide/glycolide (PLGA). Chondrogenic media was supplemented with 25 µg/mL CTGF starting at day 0 or 7. Messenger RNA (mRNA) for Collagen I, II, X, fibrillin, and elastin was quantified by RT-PCR; glycosaminoglycan (GAG) matrix deposition was assessed and normalized by cellular DNA content. Elastin protein was assessed by Western blot analysis. All experiments were performed in triplicate with MSCs from 4 distinct cords. Multiway analysis of variance with Newman-Keuls post test was used to determine statistical significance. RESULTS: Connective tissue growth factor treatment results in increased GAG/DNA ratio; the differentiation index was maintained above 1 in all conditions, with increased collage II noted at days 7 and 14 in CTGF conditions; no difference in collagen X or fibrillin mRNA was noted. Increased elastin mRNA and protein were noted at day 14 in conditions treated with CTGF at day 7 after differentiation. CONCLUSIONS: Connective tissue growth factor leads to maximal elastin increase in UCMSCs after 7 days of chondroinduction and not in undifferentiated MSCs. With appropriately timed treatment, CTGF may be a useful adjunct in maintaining an elastic cartilage phenotype in engineered cartilage from human UCMSCs.

Analyzing the Time From Discovery to Definitive Surgical Therapy for Lung Cancer Based on Referral Patterns.

OBJECTIVE: Surgery for early stage non-small cell lung cancer can be curative. A delay from diagnosis to surgery can lead to increased mortality. Our objective was to determine if referring patients to specialists before a thoracic surgeon caused a delay in definitive treatment. MATERIALS AND METHODS: A retrospective review was conducted of patients who had surgery for non-small cell lung cancer by a single surgeon at our institution from 2013 to 2016. Patients were divided into 2 groups: those who saw a specialist before a thoracic surgeon and patients who were referred directly to a surgeon once the pulmonary nodule was identified on computed tomography (CT). The time from initial CT to resection was compared. Secondary analysis compared private insurance versus Medicare/Medicaid. Percentage of patients upstaged was compared. RESULTS: There was no significant difference between groups when comparing time from CT to surgery (79.88 vs. 79.90 d; P=0.58). There was a significant decrease in time from CT to surgery for patients with private insurance compared with Medicare/Medicaid patients (66.05 vs. 86.99 d; P=0.03) and fewer private insurance patients were upstaged (22.9% vs. 31.8%; P=0.32). More patients who saw a different specialist first were upstaged compared with patients sent directly to thoracic surgery (32.6% vs. 22.2%; P=0.22). CONCLUSIONS: When comparing time from CT detection of a lung nodule to surgery, no significant difference was found between patients sent to nonthoracic specialists first and those referred directly to a thoracic surgeon. There was a significant decrease in time from CT to surgery for patients with private insurance compared with Medicare/Medicaid.

Outcomes and Trends in Colorectal Surgery in U.S. Veterans: A 10-year Experience at a Tertiary Veterans Affairs Medical Center.

Introduction: The past decade has witnessed numerous advances in colorectal surgery secondary to minimally invasive surgery, evidence-based enhanced recovery programs, and a growing emphasis on patient-centered outcomes. The purpose of this study is to benchmark outcomes and experiences of patients undergoing colorectal surgery at a tertiary Veterans Affairs Medical Center for a 10-year period. Materials and Methods: Veterans who underwent nonemergent colorectal procedures between 2008 and 2018 were identified using targeted Current Procedural Terminology (CPT) codes and the Computerized Patient Record System. Patient outcomes were captured using the Veterans Affairs Surgical Quality Improvement Program and focused on length of stay and aggregate postoperative morbidity profiles. SAS® Version 9.4 (SAS Institute Inc., Cary, NC) was used for all data analysis with P < .05 used to indicate significance. Results: In total, 327 patients underwent colon/rectal resection at our medical center. Of whom 95% of patients were male and the average age was 66 years. The median length of stay after surgery was 8 days. Within the 30-day postoperative period, the composite morbidity score was 24.1%: most notable being superficial surgical site infections (6.5%), wound dehiscence (4.6%), and pneumonia (3.1%). Over the course of the study period, the laparoscopic approach increased in utilization, with 22.2% of cases performed laparoscopically in 2008 that rose to 61.1% in 2018. Conclusion: Cataloging this decade of practice provides a foundation for future changes in the field of colorectal surgery and in the treatment of veterans. Understanding historical outcomes should help identify areas for ongoing process improvement and guide targeted approaches to quality metrics.

The outcomes of two robotic platforms performing transanal minimally invasive surgery for rectal neoplasia: a case series of 21 patients.

Colorectal cancer remains the third most common cancer effecting adults. Surgical guidelines recommend transanal excision of early rectal neoplasia up to 8 cm from the anal verge. A retrospective review of two novel approaches for transanal robotic local excision with R0 resections of rectal cancers which was, on average, higher than 8 cm. Twenty-one cases of robotic assisted transanal surgery for early stage disease (T0-T1, N0) were reviewed. The first 10 cases performed with the da Vinci® Si robotic platform between 2013 and 2016, and the first 11 cases performed using the Flex® Medrobotics platform between August 2017 and August 2018. The average distance from the anal verge was 11.1 cm and 9.5 cm for the da Vinci® Si and Flex® Colorectal Drive, respectively. The average operative time was 167.6 min for the da Vinci® Si and 110.1 min for the Flex® Colorectal Drive; the average EBL was 37.5 cc and 9.1 cc for the da Vinci® Si and Flex® Colorectal Drive. In the da Vinci® series, four cases required intraoperative conversion. In the Flex® series, one case was aborted due to unfavorable robotic positioning. All margins were histologically negative when surgically complete with no recurrences to date. Transanal robotic surgery may provide a method to address rectal lesions farther from the anal verge than previously described. The Flex® Colorectal Drive platform may provide superior ability to navigate the nonlinear anatomy of the rectum and distal sigmoid colon.

A NSQIP analysis of trends in surgical outcomes for rectal cancer: What can we improve upon?

BACKGROUND: There is significant variation in rectal cancer outcomes in the USA, and reported outcomes have been inferior to those in other countries. In recognition of this fact, the American College of Surgeons (ACS) recently launched the Commission on Cancer (CoC) National Accreditation Program for Rectal Cancer (NAPRC) in an effort to further optimize rectal cancer care. Large surgical databases will play an important role in tracking surgical and oncologic outcomes. Our study sought to explore the trends in surgical outcomes over the decade prior to the NAPRC using a large national database. METHODS: The ACS National Surgical Quality Improvement Program (NSQIP) database from 2005 to 2017 was used to select colorectal cancer cases which were divided into abdominal-colonic (AC) and pelvic-rectal (PR) cohorts based upon the operation performed. Outcomes of interest were occurrence of any major surgical complication, mortality within 30 days of procedure, and postoperative length of stay (LOS). Chi-square and two sample t-tests were used to evaluate association between various risk factors and outcomes. Modified Poisson regression was used to compare and estimate the unadjusted and adjusted effect of procedure type on the outcomes. STATA 15.1 was used for analysis and statistical significance was set at 0.05. RESULTS: A total of 34,159 patients were analyzed. AC cases constituted 50.7% of the overall cohort. The two groups were relatively similar in demographic distribution, but the PR patients had higher rates of hypoalbuminemia and were sicker (ASA class 3 or greater). Rates of non-sphincter preserving operations ranged from 30 to 34%. Higher complication rates in the PR cohort were mainly infectious and surgical site complications, while rates of deep vein thrombosis and pulmonary embolism were similar between the two cohorts. On bivariate analysis, rates of mortality were similar between the two groups (AC: 1.02% vs PR: 0.91%, p = 0.395), while PR patients were found to be 1.36 times (95% CI: 1.32-1.41) more likely to have major complications and 1.40 times (95% CI: 1.35-1.44) more likely to have an extended LOS as compared to the AC patients. After multivariable analysis, PR patients continued to have a higher likelihood of major complications (IRR: 1.31, 95% CI 1.25-1.36) and extended LOS (IRR: 1.38, 95% CI: 1.33-1.43). 10-year trends showed a significant reduction in the percentage of patients with prolonged lengths of hospitalization as well as a reduction of nearly 20% in the mean LOS, but without improvement in morbidity or mortality. CONCLUSIONS: Patients undergoing PR operations were more likely to have had major complications than were patients who underwent AC procedures; unfortunately no improvement in the rate of these complications or in mortality occurred. Perhaps the significant reduction in LOS is due in part to an increased prevalence of minimally invasive surgery and/or enhanced recovery protocols. Data were found to be lacking within NSQIP for several important variables including key oncologic data, stratification by surgical volume, and patient geographic location. We anticipate that the NAPRC should help improve PR surgical and oncologic outcomes including decreasing morbidity and mortality rates during the next decade.

A review of deep infiltrative colorectal endometriosis treated robotically at a single institution.

PURPOSE/BACKGROUND: Using robotic surgery, we report successful resection of deep invasive pelvic endometriosis with a multidisciplinary team of colorectal and gynecologic surgeons. METHODS/INTERVENTIONS: Fifteen cases of robotic-assisted endometrial resections for deep invasive endometriosis were performed by a multidisciplinary team between 2013 and 2016. RESULTS/OUTCOMES: The average total operative time of robotic endometrial extirpation was 342 minutes, and the average blood loss was 283 cc. There were no intraoperative complications and no conversion to laparotomy. Postoperative complications, including one superficial wound infection, four patients with pelvic abscesses, a bowel leak, and one rectovaginal fistula, occurred in five of 15 patients, three of which required percutaneous drainage and one required reoperation. All patients who followed up after surgery showed 100% dysmenorrhea resolution at one month (13 of 15 patients). CONCLUSION/DISCUSSION: Deep infiltrating endometriosis is a complex disease associated with significant morbidity and requires highly trained, multidisciplinary team approach for safe and efficient excision.

Minimally Invasive Surgery for Rectal Adenocarcinoma Shows Promising Outcomes Compared to Laparotomy, a National Cancer Database Observational Analysis.

PURPOSE/BACKGROUND: The surgical approach to adenocarcinoma of the rectum remains a controversial topic. Although current data focus on the noninferiority of minimally invasive surgery (MIS) for rectal cancer compared with laparotomy, conclusions are drawn from smaller sample sizes and may be underpowered. Methods/Interventions: The National Cancer Database (NCDB) from 2010 to 2014 was reviewed for all cases of invasive adenocarcinoma of the rectum (SEER Histology Codes 8140) who underwent surgical resection for malignancy. Groups were separated based on laparotomy or an MIS approach and stratified by NCDB Analytic Stage. Multivariate Cox regression analysis was used to evaluate for survival after diagnosis of adenocarcinoma of the rectum. Results/Outcomes: The inclusion criteria identified 29,199 cases of adenocarcinoma of the rectum managed surgically. After controlling for differences in the cohorts, survival after diagnosis and definitive surgical treatment for adenocarcinoma of the rectum is improved when an MIS approach was used (adjusted hazard ratio [HR] = 0.82, 95% confidence interval [CI] = 0.77-0.88, P < .001). The protective effect of an MIS approach applied to Stages I, II, III, and IV adenocarcinoma of the rectum. The protective effect of a minimally invasive surgical approach applies to Stages I, II, III, and IV adenocarcinoma of the rectum. The rate of negative circumferential margins (86.2% versus 83.5%, P < .001), proximal and distal margins (94.7% versus 92.1%, P < .001), and lymph node yield >12 (73.2% versus 70.1%, P < .001) was higher in the minimally invasive group compared with laparotomy. The intraoperative conversion rate from MIS to laparotomy was 13.9%. CONCLUSION/DISCUSSION: Minimally invasive resection for adenocarcinoma of the rectum shows promising survival benefit compared with open surgery after adjusting for measured confounds.

Impact of Operative Times and Mesh Utilization on Paraesophageal Hernia Repair: Analysis of 30-Day Outcomes from the American College of Surgeons National Surgical Quality Improvement Project Database.

BACKGROUND: Using mesh to buttress the crural repair following a paraesophageal hernia repair remains controversial. This article evaluates recent trends in laparoscopic paraesophageal hernia repairs and analyzes the impact of mesh and operative time on postoperative morbidity. METHODS: The 2013-2015 American College of Surgeons National Surgical Quality Improvement Project (ACS-NSQIP) database was queried for elective laparoscopic paraesophageal hernia repair with and without mesh. Operative times were grouped into quartiles and statistical analysis was performed using analysis of variance univariate with post hoc testing and multivariate regression modeling. The outcomes of interest were composite morbidity scores and readmission rates within 30 days of surgery. RESULTS: The database identified a cohort of 6234 laparoscopic paraesophageal hernia repairs. Mesh was utilized in 42% of cases per year and did not change over the study period (P = .367). Mesh was used 37%, 40%, 43%, and 49% of the time within operative quartiles 1, 2, 3, and 4, respectively (P < .001). Postoperative morbidity and readmission rates for each operative time quartile were 2.8%, 4.1%, 5.42%, and 6.13% (P < .001) and 4.4%, 5%, 6.2%, and 7.6% (P = .001), respectively. Post hoc testing indicated statistically significant differences in postoperative morbidity and readmission rates between quartiles 1 and 3/4. Multivariate regression analysis documented operative time as a risk factor for postoperative morbidities and readmission. Simply using mesh was not directly associated with postoperative morbidity. CONCLUSION: Mesh utilization does not impact postoperative outcomes; however, as operative time increases, the incidence of postoperative morbidity also increases.

Sudden Heart Rate Reduction Upon Optogenetic Release of Acetylcholine From Cardiac Parasympathetic Neurons in Perfused Hearts.

The balance of sympathetic and parasympathetic tone provides exquisite control of heart rate and contractility and has also been shown to modulate coronary flow and inflammation. Understanding how autonomic balance is altered by cardiac disease is an active area of research, and developing new ways to control this balance provides insights into disease therapies. However, achieving acute neuron-specific stimulation of autonomic neurons can be difficult in experiments that measure the acute effects of nerve stimulation on the heart. Conventional electrical and pharmacological approaches can be spatially and temporally non-selective. Cell-specific expression of light-activated channels (channelrhodopsin, ChR2) is a powerful approach that enables control of the timing and distribution of cellular stimulation using light. We present such an optogenetic approach where parasympathetic cardiac neurons are selectively photoactivated at high temporal precision to initiate cholinergic-mediated slowing of heart rate. Mice were crossbred to express ChR2 in peripheral cholinergic neurons using Cre-Lox recombination driven by a choline acetyltransferase (ChAT) promoter. Hearts from adult mice were excised, perfused, and the epicardium was illuminated (peak 460-465 nm) to photoactivate ChR2. In one set of studies, hearts were illuminated using a large-field LED light source. In other studies, a micro LED was placed on the right atrium to selectively illuminate the junction of the superior vena cava (SVC) and right atrium. The ECG was acquired before, during, and after tissue illumination to measure changes in heart rate. Upon illumination, hearts exhibited sudden and dramatic reductions in heart rate with restoration of normal heart rate after cessation of illumination. Delays in atrioventricular conduction were also observed. Heart rate reductions at the highest irradiance levels were similar to heart rate reductions caused by application of bethanechol (10 µM) or acetylcholine (800 µM). Atropine (50 nM) completely blocked the effect of ChR2 photoactivation, confirming cholinergic mediation. Optogenetic activation of intrinsic parasympathetic neurons reduced heart rate in an immediate, dose-dependent fashion, resembling the slowing of sinus rate in response to acetylcholine. Our results demonstrate a new approach for controlling parasympathetic modulation of cardiac function by selectively activating the endogenous release of acetylcholine from intrinsic cardiac cholinergic neurons. Key Message: Optogenetic photoactivation of intrinsic cardiac neurons provides immediate, tissue-specific stimulation with minimal cross-reactivity. Our results demonstrate that selective expression of channelrhodopsin within cardiac cholinergic neurons enables photoactivated release of acetylcholine, thereby instantaneously slowing sinus rate and altering atrioventricular conduction. This provides for in-depth examination of the endogenous interplay between cardiac autonomic neurons and the functional outcomes of downstream post-synaptic receptor activation.

Robotic transanal microsurgery for high early rectal neoplasia (T0-T1, N0 lesions), case series of 10 patients.

PURPOSE/BACKGROUND: In 2017, an estimated 39 910 people will receive a new diagnosis of rectal cancer. Current surgical guidelines limit transanal excision of early rectal neoplasia to 8 cm from the anal verge. We report that R0 resection of higher rectal cancers is possible using transanal robotic microsurgery. METHODS/INTERVENTIONS: Ten cases of robotic assisted transanal surgery for early stage disease (T0-T1, N0) between 2013 and 2016 were reviewed. RESULTS/OUTCOMES: All cases were diagnosed preoperatively with colonoscopy, and the average distance from the anal verge was 11.1 cm. The average operative time was 167 minutes, and the average blood loss was 37.5 cc. Four cases required intraoperative conversion; one conversion required robotic abdominal access to repair a proctotomy. All margins were histologically negative, and 6-month follow-up showed no recurrences. CONCLUSION/DISCUSSION: Transanal robotic surgery may provide the colorectal surgeon a method to address rectal lesions farther from the anal verge.

A case report of successful management of clostridium difficile colitis with antegrade Fidaxomicin through a mucous fistula obviating the need for subtotal colectomy.

INTRODUCTION: Clostridium difficile is the most common cause of healthcare-associated infections and can have devastating morbidity and mortality. Traditional treatment algorithms involve intravenous metronidazole and enteric metronidazole or vancomycin. Fidaxomicin (DificidR) targets "switch regions" within RNA polymerases and effectively kills clostridium difficile bacteria and is typically administered orally primarily or through a naso/oro-gastric conduit. PRESENTATION OF CASE: 55-year-old with a recent elective surgical procedure was hospitalized with multifocal pneumonia and subsequently developed clostridium difficile colitis. This patient failed the standard medical therapy for clostridium difficile colitis, decompensated and required surgical exploration, partial colectomy and mucous fistula creation. Following her surgery, her clinical condition improved and her colitis resolved with the antegrade administration of fidaxomicin through her mucous fistula. DISCUSSION: Fidaxomicin is a newer to market therapeutic agent that has been shown to be effective in the treatment of clostridium difficile colitis. Previously studies have shown benefit of oral fidaxomicin therapy for fulminant clostridium difficile but our study case report describes the index case of topical fidaxomicin through a mucous fistula. CONCLUSION: In our case of fulminant clostridium difficile colitis, Fidaxomicin administered in an antegrade fashion through a mucous fistula may have reduced the need for total colectomy in the treatment of fulminant clostridium difficile colitis.

Outcomes of beating heart on pump utilizing a miniature bypass circuit versus off-pump cardiac bypass at a Veterans Affairs Medical Center.

BACKGROUND: Off-pump coronary artery bypass grafting (OPCAB) helps reduce systemic inflammatory changes by maintaining native pulsatile flow. This analysis evaluates the outcomes of OPCAB at a Veterans Affairs Medical Center (VAMC) and evaluates the use of beating heart on-pump (BHOP) bypass grafting as an empiric therapy for high-risk patients. METHODS: We performed a retrospective analysis of 756 patients who underwent coronary bypass grafting between 2004-2015 at a single VAMC. This group was subdivided into BHOP (N.=60) versus OPCAB (N.=696). Analysis was performed using multivariate regression modeling with P=0.05 holding statistical significance. RESULTS: Both cohorts were predominantly male with an average age of 65 years and average Body Mass Index of 30 kg/m2. Individuals in the BHOP group were more likely to have COPD and resting ST depressions preoperatively. Operative time was longer and average number of conduits was higher for BHOP cases compared to OPCAB cases respectively. After controlling for differences between cohorts, multivariate regression analysis showed a protective effect of both BHOP (OR 0.325, P=0.035; OR 0.323, P=0.031) and two (OR 0.385, P<0.001; OR 0.539, P=0.018) and three (OR 0.154, P<0.001; OR 0.315, P<0.001) vessel revascularization on three and six-year mortality following revascularization. CONCLUSIONS: Postoperative survival following BHOP is superior to OPCAB when BHOP is used empirically with no difference in short-term mortality. Empiric use of BHOP should be considered for high risk coronary revascularization.

Laparoscopic Sleeve Gastrectomy for Morbid Obesity at a Veterans Affairs Medical Center.

BACKGROUND: Class III obesity is a global health emergency associated with an increase in the incidence of many other diseases such as type 2 diabetes mellitus, hypertension, hyperlipidemia, cancer, obstructive sleep apnea, nonalcoholic fatty liver disease, osteoarthritis, infertility, and mental health disorders. Minimal work has been published regarding the efficacy of laparoscopic sleeve gastrectomy (LSG) in the veteran population to surgically manage morbid obesity. DESIGN: Retrospective analysis of LSG performed at a Veterans Affairs Medical Center (VAMC) between 2010 and 2017. Veterans were followed from their enrollment in the bariatric program until twelve months following LSG. The primary outcome of interest was excess and total weight loss with resolution of associated comorbidities. RESULTS: Excess weight loss at nine and 12 months was 43.5% and 40.7% and total weight loss was 20.1% and 19.0%, respectively. LSG performed at a VAMC resulted in 86.9% improvement in type 2 diabetes mellitus and a 66.1% improvement in hypertension and 74.3% improvement in hyperlipidemia. Approximately 10.0% of diabetics obtained partial and 9.0% obtained complete resolution of their disease. Similarly, 22.0% of Veterans obtained partial and 13.0% obtained complete resolution from hypertension. Complete resolution from hyperlipidemia was achieved in 8.8% of Veterans. There were no postoperative complications or staple line leaks. CONCLUSION: LSG is a safe and effective tool for morbid obesity with clinical and serological improvements for individuals who are unable to lose weight with medical management alone.

Right Colon Resection for Colon Cancer: Does Surgical Approach Matter?

BACKGROUND: Surgical resection with curative intent remains the standard of care for colon cancer. This study aims to compare the 30-day outcomes and oncologic results following open, laparoscopic, and robot-assisted right colon resection for colon cancer using the Targeted Colectomy American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. MATERIALS AND METHODS: All patients undergoing elective, right colon resection with primary anastomosis were identified within the targeted colectomy ACS-NSQIP database. Only patients with stage I, II, or III colon cancer were included. The association of surgical approach with oncologic results and 30-day morbidity and mortality outcomes was investigated using a variety of statistical tests. RESULTS: A total of 3518 patients met inclusion criteria; 1024 (29.1%) underwent open surgery (OS), 2405 (63.4%) underwent laparoscopic surgery, and 89 (2.5%) underwent robotic surgery. Patients undergoing OS were significantly more likely to have positive resection margins (P < .001). Patients undergoing OS were significantly more likely to experience prolonged intubation (P = .02), deep wound infections (P = .001), wound dehiscence (P = .005), deep venous thrombosis (P = .04), bleeding requiring a blood transfusion (P < .001), a prolonged postoperative ileus (P < .001), and longer length of hospital stay (P < .001), and were more likely to die (P = .02). CONCLUSION: The laparoscopic approach to colon resection for colon cancer has lower 30-day morbidity compared to OS. The robotic approach is equivalent to the laparoscopic approach, and its utilization may increase in the future.