Feasibility and Safety of Laparoscopic Colon Surgery Performed Under Intravenous Sedation and Local Anesthesia Using Microinvasive (<3 mm) Instruments: An Acute and Survival Study on Porcine Model.

PURPOSE: The purpose of the study was to evaluate the feasibility and safety of performing laparoscopic intestinal surgery using local anesthesia and intravenous sedation with instruments <3 mm in diameter. METHODS: Porcine model with acute (n = 2) and the survival studies (n = 8): all female pigs, weight (median 36.4 kg, range 33.2-38.4 kg). Surgeries were performed using only intravenous sedation with ketamine-midazolam and local anesthetic infiltration at the sites of trocar insertion, with airway protection. CO2 pneumoperitoneum was maintained using pressure of 3 to 5 mm Hg. Commercially available instruments, sizes <3 mm in diameter were used. Surgical steps were as follows: (a) exploration of all quadrants of the abdomen and pelvis, (b) "running" the entire length of small bowel, (c) dissection of bowel attachments to the peritoneal sidewall, and (d) creating a 2.5 cm enterotomy in the colon and suture repair of this defect. RESULTS: All 10 surgeries were completed successfully. Animals tolerated the procedure well, with no requirement of intubation. There were no decrements in vital signs during pneumoperitoneum or surgery. Despite spontaneous respiration movements, all planned surgical maneuvers were feasible. The median length of operations was 74 minutes (range 56-165 minutes). All survival animals had an uneventful recovery; there were no infectious complications, oral intake and bowel function returned within 24 hours. CONCLUSIONS: It appears feasible and safe to perform simple laparoscopic intestinal procedures using instruments <3 mm in diameter and low CO2 insufflation pressure under local anesthesia and intravenous sedation. This methodology holds promise in the development of new approaches to intestinal surgery and disease diagnosis.

The influence of obesity on short- and long-term outcomes after laparoscopic surgery for colon cancer: a case-matched study of 152 patients.

BACKGROUND: Despite the increasing prevalence of obesity and colonic diseases, the impact of obesity on short-term and oncologic outcomes of laparoscopic colorectal surgery still remains unclear. STUDY DESIGN: Seventy-six consecutive obese patients with body mass index (BMI) ≥30 kg/m(2) who underwent laparoscopic colectomy were matched with 76 nonobese patients with BMI <30 kg/m(2). Perioperative parameters and oncologic outcomes were analyzed in the two groups. RESULTS: Obesity was associated with greater operative time (obese vs nonobese, 182 ± 59 vs 157 ± 55 min, P = .0084) and multivariate analysis identified BMI (hazard ratio 2.11, 95% confidence interval 0.64-3.56, P = .0049) as an independent predicting factor for operative time together with cancer location (hazard ratio 28.6, 95% confidence interval 14.62-42.51, P < .0001). Obesity had no adverse influence on overall morbidity (25 vs 21%, P = .563), however, or postoperative duration of stay (median 6.0 vs 5.5 days, P = .22). Furthermore, the rate of conversion to open procedure was similar between the two groups (9 vs 9%, P > .99). Regarding oncologic outcomes, there was no statistical difference in overall and disease-free survival between the two groups (5-year overall survival rate 86 vs 89%, P = .72, 5-year disease survival rate 70 vs 77%, P = .70). CONCLUSION: Laparoscopic colonic resection, when performed for selected patients, appears to be a safe and reasonable option in obese patients with colon cancer resulting in similar short-term and oncologic outcomes as nonobese patients.

Evaluation of the safety, efficacy, and versatility of a new surgical energy device (THUNDERBEAT) in comparison with Harmonic ACE, LigaSure V, and EnSeal devices in a porcine model.

BACKGROUND: THUNDERBEAT™ (TB) (Olympus, Japan) simultaneously delivers ultrasonically generated frictional heat energy and electrically generated bipolar energy. The aim of this study was to evaluate the versatility, bursting pressure, thermal spread, and dissection time of the TB compared with commercially available devices: Harmonic(®) ACE (HA) (Ethicon Endo-Surgery, USA), LigaSure™ V (LIG) (Covidien, USA), and EnSeal(®) (Ethicon). METHODS: An acute study was done with 10 female Yorkshire pigs (weighing 30-35 kg). Samples 2 cm long of small (2-3 mm)-, medium (4-5 mm)-, and large (6-7 mm)-diameter vessels were created. One end of the sample was sent for histological evaluation, and the other was used for burst pressure testing in a blinded fashion. Versatility was defined as the performance of the surgical instrument based on the following five variables, using a score from 1 to 5 (1=worst, 5=best), adjusted by coefficient of variable importance with weighted distribution: hemostasis, 0.275; histologic sealing, 0.275; cutting, 0.2; dissection, 0.15; and tissue manipulation, 0.1. There were 80 trials per vessel group and 60 trials per instrument group, giving a total of 240 samples. RESULTS: Versatility score was higher (P<.01) and dissection time was shorter (P<.01) using TB compared with the other three devices. Bursting pressure was similar among TB and the other three instruments. Thermal spread at surgery was similar between TB and HA (P=.4167), TB and EnSeal (P=.6817), and TB and LIG (P=.8254). Difference in thermal spread was noted between EnSeal and HA (P=.0087) and HA and LIG (P=.0167). CONCLUSION: TB has a higher versatility compared with the other instruments tested with faster dissection speed, similar bursting pressure, and acceptable thermal spread. This new energy device is an appealing, safe alternative for cutting, coagulation, and tissue dissection during surgery and should decrease time and increase versatility during surgical procedures.

Endoscopic fixation of the rectum for rectal prolapse: a feasibility and survival experimental study.

BACKGROUND: In recent years, there has been considerable interest in developing technology as well as techniques that could widen the therapeutic horizons of endoscopy. Rectal prolapse, a benign localized condition causing considerable morbidity, could be an excellent focus for new endoscopic therapies. The aim of this study was to assess the feasibility and safety of endoluminal fixation of the rectum to the anterior abdominal wall, after pushing it up inside the body, using an in vivo animal model. METHODS: We performed an in vivo comparative surgical study in a porcine model, including laparoscopic mobilization of the rectum and posterior rectopexy (standard surgical method) or endoluminal tacking of the rectum. After proving feasibility in ex vivo and acute studies, we performed a survival study to evaluate the safety of endoluminal tacking of the mobilized rectum to the anterior abdominal wall. The main outcome measures were successful completion of the tasks, maintenance of the fixation, complications associated with the methods, and survival studies including histopathological examinations of the fixation sites. RESULTS: There were two groups: laparoscopic rectopexy (8 animals) and endoluminal fixation of the rectum to the anterior abdominal wall (10 animals). There were no differences between these two groups in their postoperative recovery. The group with the endoluminal fixation was found to have adequate attachment of the rectum to the anterior abdominal wall (measured attachment pressure in the endoluminal group = 6.06 ± 0.52 ft-lb, in the control group = 4.86 ± 2.00 ft-lb) on both gross and microscopic evaluation. CONCLUSION: Endoscopic fixation of the mobilized rectum is feasible and safe in this model and in the future may provide an effective alternative to current treatment options for rectal prolapse.

Evaluating the vascularity of intestinal anastomoses--can narrow band imaging play a role?

A variety of factors are critical for the success of bowel anastomoses. The most crucial patient factor is adequate vascularity of the bowel ends which are to be anastomosed. Currently, intraoperative features such as healthy looking bleeding edges of the bowel are considered to be signs of adequate vascular supply. However, once the anastomosis is performed, external appearances may not be reliable. In order to improve evaluation of the bowel as well as the anastomosis, our group has adopted the routine use of post-anastomosis intraoperative colonoscopy. Intraoperative colonoscopy provides vital information regarding the integrity of the anastomosis (leak testing) and also visualizes the mucosa of the bowel. Narrow Band Imaging (NBI) is a novel real-time imaging technique which is an integral component of many modern colonoscopes. We hypothesize that NBI assessment of vascularity at the time of intestinal anastomosis can improve safety and reduce the risks of anastomotic complications following surgery.