S. Scott Davis

Heating and humidifying of carbon dioxide during pneumoperitoneum is not indicated: A prospective randomized trial

BackgroundCarbon dioxide (CO2) pneumoperitoneum usually is created by a compressed gas source. This exposes the patient to cool dry gas delivered at room temperature (21°C) with 0% relative humidity. Various delivery methods are available for humidifying and heating CO2 gas. This study was designed to determine the effects of heating and humidifying gas for the intraabdominal environment.MethodsFor this study, 44 patients undergoing laparoscopic Roux-en-Y gastric bypass were randomly assigned to one of four arms in a prospective, randomized, single-blinded fashion: raw CO2 (group 1), heated CO2 (group 2), humidified CO2 (group 3), and heated and humidified CO2 (group 4). A commercially available CO2 heater–humidifier was used. Core temperatures, intraabdominal humidity, perioperative data, and postoperative outcomes were monitored. Peritoneal biopsies were taken in each group at the beginning and end of the case. Biopsies were subjected staining protocols designed to identify structural damage and macrophage activity. Postoperative narcotic use, pain scale scores, recovery room time, and length of hospital stay were recorded. One-way analysis of variance (ANOVA) and the nonparametric Kruskal–Wallis test were used to compare the groups.ResultsDemographics, volume of CO2 used, intraabdominal humidity, bladder temperatures, lens fogging, and operative times were not significantly different between the groups. Core temperatures were stable, and intraabdominal humidity measurements approached 100% for all the patients over the entire procedure. Total narcotic dosage and pain scale scores were not statistically different. Recovery room times and length of hospital stay were similar in all the groups. Only one biopsy in the heated–humidified group showed an increase in macrophage activity.ConclusionsThe intraabdominal environment in terms of temperature and humidity was similar in all the groups. There was no significant difference in the intraoperative body temperatures or the postoperative variable measured. No histologic changes were identified. Heating or humidifying of CO2 is not justified for patients undergoing laparoscopic bariatric surgery.

Gastrotomy closure using bioabsorbable plugs in a canine model.

The repair of gastric perforation commonly involves simple suture closure using an open or laparoscopic approach. An endolumenal approach using prosthetic materials may be beneficial. The role of bioprosthetics in this instance has not been thoroughly investigated, thus the authors evaluated the feasibility of gastric perforation repair using a bioabsorbable device and quantified gross and histological changes at the injury site. Twelve canines were anesthetized and underwent open gastrotomy. A 1-cm-diameter perforation was created in the anterior wall of the stomach and plugged with a bioabsorbable device. Intralumenal pH was recorded. Canines were sacrificed at one, four, six, eight, and 12 weeks. The stomach was explanted followed by gross and histological examination. The injury site was examined. The relative ability of the device to seal the perforation was recorded, as were postoperative changes. Tissue samples were analyzed for gross and microscopic tissue growth and compared to normal gastric tissue in the same animal as an internal control. A scoring system of −2 to +2 was used to measure injury site healing (−2= leak, −1= no leak and minimal ingrowth, 0= physiologic healing, +1= mild hypertrophic tissue, +2= severe hypertrophic tissue). In all canines, the bioprosthesis successfully sealed the perforation without leak under ex vivo insufflation. At one week, the device maintained its integrity but there was no tissue ingrowth. Histological healing score was −1. At 4–12 weeks, gross examination revealed a healed injury site in all animals. The lumenal portion of the plug was completely absorbed. The gross and histological healing score ranged from −1 to +1. The application of a bioabsorbable device results in durable closure of gastric perforation with physiologic healing of the injury site. This method of gastrotomy closure may aid in the evolution of advanced endoscopic approaches to perforation closure of hollow viscera.

Laparoscopic Versus Open Appendectomy: An Analysis of Outcomes in 17,199 Patients Using ACS/NSQIP

BackgroundThe current study was undertaken to evaluate the outcomes for open and laparoscopic appendectomy using the 2008 American College of Surgeons: National Surgical Quality Improvement Program (ACS/NSQIP) Participant Use File (PUF). We hypothesized that laparoscopic appendectomy would have fewer infectious complications, superior perioperative outcomes, and decreased morbidity and mortality when compared to open appendectomy.Study DesignUsing the Current Procedural Technology (CPT) codes for open (44950) and laparoscopic (44970) appendectomy, 17, 199 patients were identified from the ACS/NSQIP PUF file that underwent appendectomy in 2008. Univariate analysis with chi-squared tests for categorical data and t tests or ANOVA tests for continuous data was used. Binary logistic regression models were used to evaluate outcomes for independent association by multivariable analysis.ResultsOf the patients, 3,025 underwent open appendectomy and 14,174 underwent laparoscopic appendectomy. Patients undergoing laparoscopic appendectomy had significantly shorter operative times and hospital length of stay. They also had a significantly lower incidence of superficial and deep surgical site infections, wound disruptions, fewer complications, and lower perioperative mortality when compared to patients undergoing open appendectomy.ConclusionsUsing the ACS/NSQIP PUF file, we demonstrate that laparoscopic appendectomy has better outcomes than open appendectomy for the treatment of appendicitis. While the operative treatment of appendicitis is surgeon specific, this study lends support to the laparoscopic approach for patients requiring appendectomy.

A computerized analysis of robotic versus laparoscopic task performance

IntroductionRobotic technology has been postulated to improve performance in advanced surgical skills. We utilized a novel computerized assessment system to objectively describe the technical enhancement in task performance comparing robotic and laparoscopic instrumentation.Methods and proceduresAdvanced laparoscopic surgeons (2–10 yrs experience) performed three unique task modules using laparoscopic and Telerobotic surgical instrumentation (Intuitive Surgical, Sunnyvale, CA). Performance was evaluated using a computerized assessment system (ProMIS, Dublin, Ireland) and results were recorded as time (s), path (mm) and precision. Each surgeon had an initial training session followed by two testing sessions for each module. A paired Student’s t-test was used to analyze the data.ResultsTen surgeons completed the study. 8/10 surgeons had significant technical enhancement utilizing robotic technology.ConclusionsThe ProMIS computerized assessment system can be modified to objectively obtain task performance data with robotic instrumentation. All the tasks were performed faster and with more precision using the robotic technology than standard laparoscopy.

Observed Variability in Sleeve Gastrectomy Volume and Compliance Does Not Correlate to Postoperative Outcomes.

Background: Restrictive bariatric procedures reduce gastric capacity as a primary mechanism of action. Intraoperatively, surgeons observe variability in size and compliance of specimens. We hypothesized that higher gastric specimen volume or tissue compliance would respond better to restrictive procedures. Materials and Methods: Consecutive patients undergoing laparoscopic sleeve gastrectomy between September 2012 and September 2013 were enrolled. Specimens were insufflated at graduated pressure points creating pressure volume curves, and compliance was calculated. Postoperative weight loss and a hunger scores were recorded. Correlations were determined by Spearman correlation. Results: Eighty-four patients consented to enrollment. Mean age, weight, and body mass index (BMI) were 45±12 years, 126±23 kg, and 45.4±6 m/kg2, respectively. The resected specimens varied in insufflated capacity from 0.3 to 1.8 (0.71±0.32) L and compliance varied from 14.3 to 85.7 (36.1±14.7) cc/mm Hg. Male patients had a larger greater curvature length (GCL) (P<0.001), staple line length (SLL) (P=0.03), gastric volume (GV) (P=0.002), and gastric compliance (GC) (P<0.001). Neither GV nor GC correlated to excess body weight loss (EBWL%) as hypothesized. There was an inverse correlation between hunger score and GV (P=0.010). The mean 1-month, 3-month, 6-month, and 12-month EBWL was 17.4%, 33.2%, 43.7%, and 54.1%, respectively. Follow-up was 71.4% at 1 month, 39.3% at 3 months, 54.8% at 6 months, and 42.9% at 12 months. Conclusions: Sleeve gastrectomy specimens exhibit nearly 6-fold variability in both volume and compliance. A large GC is anticipated in male and tall subjects. These observations do not appear to be correlated to %EBWL.

Publication patterns and the impact of self-citation among minimally invasive surgery fellowships

INTRODUCTION The h-index is a widely utilized academic metric that measures both productivity and citation impact. The purpose of this study is to define the impact of self-citation among minimally invasive surgery (MIS) fellowship program directors. METHODS Through the Fellowship Councils website, all program directors and associate program directors from the 148 MIS fellowship programs were identified. Using the Scopus database, we calculated the number of publications, citations, self-citations, and h-index for each surgeon. RESULTS A total of 274 surgeons were identified. The mean number±SD of publications, citations, and h-index for the cohort were 60.5 ± 77.2, 1765 ± 4024, and 16.0 ± 15.0, respectively. The self-citation rate for the entire cohort was 3.23%. Excluding self-citations reduces the mean number of citations to 1708 ± 3887 and h-index to 15.8 ± 14.6. The h-index remained unchanged for 77% (210/274) of surgeons. Only 5% (15/274) of surgeons had a change in h-index of greater than one integer and no surgeon had a change greater than three integers. CONCLUSION Self-citation is infrequent and has a minimal impact on the academic profile of program directors of MIS fellowships.

A New Objective Skills Assessment System for Telerobotic Surgery

eradicate some of the pitfalls of laparoscopic surgery. Herein we report a single-institution 4-year experience with RAMIS. Materials and Methods: All patients undergoing RAMIS using the Da Vinci system were included in the study. Data were prospectively collected for every procedure. Results: Between August 2000 and June 2005, 468 patients underwent RAMIS. There were 278 women and 190 men. The average age was 48 years (14 to 75). The procedures performed were: 96 Roux enY-Gastric Bypass, 30 Adjustable gastric banding, 71 Heller myotomies, 13 Antireflux surgeries, 6 Epifrenic Diverticulectomies, 20 Transhiatal esophagectomies, 3 Esophageal leiomyoma resections, 1 Pyloroplasty, 2 Gastroyeyunostomies, 2 Transduodenal Sphincteroplasties, 10 Adrenalectomies, and 213 Donor nephrectomies. Operative time for antireflux surgery, and lap band was longer with RAMIS than conventional MIS. After our early experience, operative time and morbidity for Heller myotomy, gastric bypass, donor nephrectomies, and esophagectomies dropped significantly with RAMIS. There were no leaks after gastric bypass and no mucosal perforations after esophageal myotomy. There was decreased blood loss with total esophagectomy. Conversion to conventional MIS or to open surgery occurred in 7 (1.6%) patients (1 transduodenal sphincteroplasty, 1 gastric bypass, and 5 donor nephrectomies). Hospital stay after RAMIS was similar to conventional MIS. There was no robotic-specific morbidity or mortality. Conclusions: This study shows that RAMIS can be safely used in clinical settings. The theoretical advantages of the da Vinci system seemed to be evident for certain surgical procedures. Prospective randomized trials comparing robotic and laparoscopic surgery are needed to confirm the current results.