Evaluation of the learning curve for natural orifice transluminal endoscopic surgery: bilateral ovariectomy in dogs.

OBJECTIVE: Study the learning curve for canine Natural Orifice Transluminal Endoscopic Surgery (NOTES) ovariectomy by evaluating operative times and complications. STUDY DESIGN: Preclinical research study. ANIMALS: Adult female dogs (n=20). METHODS: NOTES ovariectomy procedures were performed as follows: Feasibility Group 1 (n=5), Feasibility Group 2 (n=5), and Early Clinical Group 3 (n=10). Six steps of the procedure were identified, timed separately, and the overall time was recorded from introduction to removal of the endoscope. Complications were recorded. Repeated measures analysis of variance using ranked data compared the effect of group (3 levels) on the time for each step. Nonlinear regression using an exponential model with nonzero asymptote was used to model the operative time-procedure number relationship. RESULTS: Overall median operative time was significantly longer for Group 1 (195 minutes; range, 160-265 minutes) than Group 2 (108 minutes; range, 81-148 minutes; P=.048) and Group 3 (77 minutes; range, 41-136 minutes; P=.0008). The estimated asymptotic operative time was 71 minutes (95% confidence interval, 41-100 minutes); this time was reached after 10 procedures. Gastric cleansing and removing the left ovary took significantly longer in Group 1 than in Group 2 or 3. Operative complications included incomplete ovarian excision, dropping an ovary during retrieval, and conversion to an open procedure. No intraoperative complications occurred in Group 3. CONCLUSION: NOTES procedures result in longer operative times in the early part of the learning curve and require considerable experience before reaching proficiency.

Comparison of pain and postoperative stress in dogs undergoing natural orifice transluminal endoscopic surgery, laparoscopic, and open oophorectomy.

BACKGROUND: Few studies are available to compare the potential benefits of natural orifice transluminal endoscopic surgery (NOTES) approaches to traditional surgery. OBJECTIVE: To compare complications, surgical stress, and postoperative pain. DESIGN: Prospective study in dogs. SETTING: Research laboratory. SUBJECTS: Thirty dogs. INTERVENTIONS: Oophorectomy procedures were performed via NOTES and laparoscopic and traditional open surgery. MAIN OUTCOME MEASUREMENTS: Operative time, pain scores, systemic stress parameters (cortisol, glucose), surgical stress markers (interleukin 6, C-reactive protein), 3-day observation. RESULTS: Median operative times were 76, 44, and 35 minutes for the NOTES, laparoscopic, and open procedures, respectively, with the NOTES procedure being significantly longer than the other 2 procedures. All ovaries were completely excised, and all the animals survived without complications. The NOTES animals had greater increases in serum cortisol concentrations at 2 hours but no statistically significant differences in glucose concentrations compared with the other groups. Serum interleukin 6 and C-reactive protein concentrations were significantly increased at specific times compared with baseline in the NOTES group, but not in the open or laparoscopic surgery groups. Based on the cumulative pain score and nociceptive thresholds, the animals in the NOTES group demonstrated less evidence of pain. LIMITATIONS: Small sample size, limited follow-up. CONCLUSIONS: Although the NOTES oophorectomy procedures took approximately twice as long and there may be more evidence of tissue damage as judged by increases in serum cortisol and interleukin 6 concentrations, the dogs in the NOTES group had lower pain scores, especially when compared with animals undergoing open surgery.

Oophorectomy by natural orifice transluminal endoscopic surgery: feasibility study in dogs.

BACKGROUND: Natural orifice transluminal endoscopic surgery (NOTES) represents a potentially less-invasive alternative to conventional or laparoscopic surgery. OBJECTIVE: Our purpose was to develop a canine oophorectomy model for prospective evaluation of intraoperative complications, surgical stress, and postoperative pain and recovery with NOTES. DESIGN: Feasibility study. SETTING: Academic preclinical research. PATIENTS: Ten healthy female dogs. INTERVENTIONS: NOTES procedures were performed through gastric access with an electrocautery snare to resect and retrieve the ovaries. The gastrotomy was closed with prototype T-fasteners. MAIN OUTCOME MEASUREMENTS: Operative time; complications; postoperative pain scores, and nociceptive threshold; surgical stress markers (interleukin-6 [IL-6], C-reactive protein); systemic stress parameters (cortisol, glucose); necropsy evaluation at 10 to 14 days. RESULTS: The mean operative time was 154 minutes (SD +/- 58 minutes) and no animals died as a result of complications from the procedure. The primary difficulty was incomplete ovarian excision and conversion to an open procedure in 1 dog. Serum glucose concentrations increased after surgery and remained elevated for at least 36 hours. The serum cortisol concentration was transiently increased from baseline at 2 hours after surgery. The serum IL-6 concentration peaked at 2 hours after surgery and returned to the baseline value by 18 hours. The serum C-reactive protein concentration increased significantly from baseline, peaked at 12 hours after surgery, and then slowly declined toward baseline but remained elevated at 72 hours after surgery. Nociceptive threshold measurements indicated increased sensitivity to pain for 2 to 24 hours after surgery. At necropsy, surgical sites were healing uneventfully with no significant damage to surrounding organs, no significant growth on bacterial cultures, and no evidence of peritonitis. LIMITATIONS: Small number of animals, single center. CONCLUSIONS: The NOTES approach to oophorectomy in dogs appears to be a reasonable alternative to traditional surgery. Attention must be paid to ensure complete excision of the ovaries.

Screening for Barrett's esophagus in colonoscopy patients with and without heartburn.

BACKGROUND & AIMS: The population prevalence of Barrett's esophagus (BE) is uncertain. Our aim was to describe the prevalence of BE in a volunteer population. METHODS: Upper endoscopy (EGD) was performed in 961 persons with no prior history of EGD who were scheduled for colonoscopy. Symptom questionnaires were completed prior to endoscopy. Biopsy specimens were taken from the gastric cardia and any columnar mucosa extending > or =5 mm into the tubular esophagus and from the stomach for H. pylori infection in the last 812 patients. RESULTS: The study sample was biased toward persons undergoing colonoscopy, males, and persons with upper GI symptoms. The prevalence of BE was 65 of 961 (6.8%) patients, including 12 (1.2%) with long-segment BE (LSBE). Among 556 subjects who had never had heartburn, the prevalences of BE and LSBE were 5.6% and 0.36%, respectively. Among 384 subjects with a history of any heartburn, the prevalences of BE and LSBE were 8.3% and 2.6%, respectively. In a univariate analysis, LSBE was more common in those with any heartburn vs. those with no heartburn (P = 0.01), but the sample size was insufficient to allow multivariate analysis of predictors of LSBE. In a multivariate analysis, BE was associated with increasing age (P = 0.02), white race (P = 0.03), and negative H. pylori status (P = 0.04). Overall, BE was not associated with heartburn, although heartburn was more common in persons with LSBE or circumferential short segments. CONCLUSIONS: LSBE is very uncommon in patients who have no history of heartburn. SSBE is relatively common in persons age > or =40 years with no prior endoscopy, irrespective of heartburn history.