Repletion of S-nitrosohemoglobin improves organ function and physiological status in swine after brain death.

OBJECTIVE: To determine if reduction in nitric oxide bioactivity contributes to the physiological instability that occurs after brain death and, if so, to also determine in this setting whether administration of a renitrosylating agent could improve systemic physiological status. BACKGROUND: Organ function after brain death is negatively impacted by reduced perfusion and increased inflammation; the magnitude of these responses can impact post-graft function. Perfusion and inflammation are normally regulated by protein S-nitrosylation but systemic assessments of nitric oxide bioactivity after brain death have not been performed. METHODS: Brain death was induced in instrumented swine by inflation of a balloon catheter placed under the cranium. The subjects were then serially assigned to receive either standard supportive care or care augmented by 20 ppm of the nitrosylating agent, ethyl nitrite, blended into the ventilation circuit. RESULTS: Circulating nitric oxide bioactivity (in the form of S-nitrosohemoglobin) was markedly diminished 10 hours after induction of brain death-a decline that was obviated by administration of ethyl nitrite. Maintenance of S-nitrosohemoglobin was associated with improvements in tissue blood flow and oxygenation, reductions in markers of immune activation and cellular injury, and preservation of organ function. CONCLUSIONS: In humans, the parameters monitored in this study are predictive of post-graft function. As such, maintenance of endocrine nitric oxide bioactivity after brain death may provide a novel means to improve the quality of organs available for donation.

Evidence for a metabolic mechanism in the improvement of type 2 diabetes after sleeve gastrectomy in a rodent model.

BACKGROUND: Sleeve gastrectomy (SG) is at least as effective at producing weight loss as gastric banding but may be superior in producing remission of type 2 diabetes mellitus (T2DM). The objective of this study was to elucidate mechanisms of diabetes improvement in SG beyond caloric restriction. We studied SG in Zucker Diabetic Fatty (ZDF) rats. METHODS: Twenty-eight ZDF rats were randomly assigned to 1 of 3 groups: SG, sham-operated ad lib fed (AL), or sham-operated pair fed (PF). SG and AL rats had free access to food. PF rats were fed the average daily intake of the SG group. Comparisons of caloric intake, weight loss, intraperitoneal glucose tolerance testing (IPGTT), insulin, and total ghrelin were performed preoperatively and at postoperative days 10, 20, and 30. Differences between means were evaluated using one-way ANOVA and the paired t test as appropriate. RESULTS: Postoperatively, SG rats had lower daily caloric intake than the AL controls (78.3±10.5 kcal versus 104.7±4.6 kcal). Both SG and PF groups had sustained weight loss (-5.3±3.8 g and -27.5±2.6 g, respectively); however, SG rats had significantly lower AUC for glucose after IPGTT than both controls. This is in contrast to AL controls that experienced weight gain (34.1±4.7 g) and increases in AUC for glucose after IPGTT. CONCLUSION: Although SG is considered a restrictive procedure, there is evidence for a metabolic effect by virtue of decreased insulin resistance, which may not be reproduced by PF controls.

In vivo assessment of an absorbable and nonabsorbable knotless barbed suture for laparoscopic single-layer enterotomy closure: a clinical and biomechanical comparison against nonbarbed suture.

BACKGROUND: Laparoscopic intracorporeal suturing and knot tying is a complex skill that requires repeated deliberate practice to master. A novel self-anchoring barbed suture material that does not require knot tying can eliminate knot failure and reduce operating time. The goal of this study was to compare the in vivo efficacy of two novel knotless barbed sutures (absorbable and nonabsorbable) for use with the Endo Stitch™ device (Covidien), against conventional suture (Endo Stitch device with Polysorb™ suture; Covidien) for laparoscopic closure of viscerotomies in canine stomach, jejunum, and colon. METHODS: Following Institutional Animal Care and Use Committee approval, 24 dogs underwent laparoscopic creation of 25-mm viscerotomies, three each in the stomach, jejunum, and colon. All viscerotomies were closed with the Endo Stitch device using the absorbable or nonabsorbable barbed suture or conventional suture. Closure time for each viscerotomy was recorded. Animals were survived for 3, 10, or 21 days, at which point the viscerotomies were burst-pressure tested. RESULTS: The closure leak rate in this study with 216 total viscerotomy closures was 0%. There was no statistically significant difference in mean burst pressure between viscerotomies closed with barbed suture versus control suture at any of the survival intervals. Barbed suture with the Endo Stitch device was associated with statistically significantly faster closure times than the control suture with the Endo Stitch device (P<.05), resulting in a reduction in closure time between 35% and 42%. CONCLUSION: This study reports the first use of barbed suture for the Endo Stitch device in laparoscopic gastrointestinal closure. The barbed suture for the Endo Stitch device is effective for laparoscopic single-layer gastrointestinal closure and is associated with a significantly reduced closure time.

Effectiveness of laparoscopic computer simulator versus usage of box trainer for endoscopic surgery training of novices.

OBJECTIVE: Teaching of laparoscopic skills is a challenge in surgical training programs. Because of the highly technical nature and the steep learning curve, students and residents must learn laparoscopic skills before performing them in the operating room. To improve efficiency of learning and patient safety, research in simulation is essential. Two types of simulators currently in use include virtual reality and box trainers. Our study examined which simulator technique was most effective in teaching novice trainees laparoscopic techniques. DESIGN: This is a prospective, randomized, blinded, controlled trial that enrolled fourth-year medical students and surgical interns to participate in a supervised 6-month laparoscopic training program with either computer simulators or box trainers. Subjects were randomized and trained on appropriate laparoscopic camera skills, instrument handling, object positioning, dissection, ligation, suturing, and knot tying. Students within one group were not allowed to practice, learn or train on the opposing trainers. At time points 0, 2, and 6 months all subjects completed a series of laparoscopic exercises in a live porcine model, which were captured on DVD and scored by blinded expert investigators. RESULTS: Scores improved overall from the pretest to subsequent tests after training with no difference between the virtual reality and box simulator groups. In the medical students specifically, there was overall improvement, and improvement in the needle-transfer and knot-tying skills specifically, with no difference between the box simulator and virtual reality groups. For the interns, both groups showed significant overall improvement with no difference between the virtual reality and box simulator groups or on individual skills. CONCLUSIONS: We conclude that laparoscopic simulator training improves surgical skills in novice trainees. We found both the box trainers and the virtual reality simulators are equally effective means of teaching laparoscopic skills to novice learners.

Left paraduodenal hernia: case report and review of the literature.

Paraduodenal hernias are congenital internal hernias that usually present with non-specific symptoms, and are therefore rarely diagnosed preoperatively. Left-sided paraduodenal hernias are three times more likely to occur than right-sided ones. Both hernias present similarly, but have a differing embryological basis. Here, the case of a 76-year-old woman with a left paraduodenal hernia presenting with small bowel obstruction is presented, and a brief discussion of the literature on its diagnosis and management given.

Obesity and bariatric surgery.

Laparoscopic Roux-en-Y gastric bypass and laparoscopic adjustable gastric banding are the most commonly performed weight reduction operations in the United States. Preoperative assessment and selection should be performed by a multidisciplinary team to obtain optimal results. The most devastating complication of bariatric surgery is leak, which can carry a high risk of mortality if not detected and treated expediently. New nationwide databases have been developed to monitor outcomes and facilitate better understanding of the mechanisms of bariatric surgery. New horizons for the advancement of bariatric surgery are in the realm of surgery in adolescent and geriatric populations, the use of weight-loss surgery in lower body mass index (<35 kg/m(2)) populations, and the use of surgery to cure the comorbidities of obesity.