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.

Cecal insertion and withdrawal times with wide-angle versus standard colonoscopes: a randomized controlled trial.

BACKGROUND & AIMS: The aim of this study was to see if a 170 degrees angle of view (wide angle [WA]) colonoscope allowed faster withdrawal without decreasing adenoma detection. METHODS: Eight colonoscopists at 2 institutions participated in the study. Patients were randomized so that each colonoscopist performed 50% of the exams with a 160 series (140 degrees angle of view; standard [ST]) colonoscope and 50% with a prototype 160 series colonoscope with a 170 degrees angle of view (WA instrument). Insertion and withdrawal times and number of polyps detected were recorded. Endoscopists were asked to withdraw as quickly as they could carefully complete the exams. Analysis of variance was done to compare insertion and withdrawal times and number of polyps detected. Time to perform biopsy, polypectomy, and cleaning was subtracted using a stopwatch. RESULTS: A total of 710 procedures were performed, 355 with ST and 355 with WA colonoscope. The mean insertion time was similar. The mean withdrawal time (absent time for suctioning, washing, etc.) with the WA colonoscope was 4.9 min which was shorter (4.9 vs 5.4 min; P = .0001) overall and for three individual endoscopists (P = .0001, P = .01, and P = .03). There was no difference in the mean number of adenomas detected per colonoscopy with ST (0.6) compared to WA (0.5) (P = .12). Two of the three endoscopists with shorter withdrawal times with WA had numerically higher detection rates with WA. CONCLUSIONS: The WA colonoscope is associated with a reduction in withdrawal time without compromising adenoma detection. However, this effect is operator dependent and the overall impact of wide-angle optics in this study was minor.

Diagnosis of esophageal adenocarcinoma by serum proteomic pattern.

BACKGROUND: Currently, endoscopic biopsy is the only method used to diagnose esophageal adenocarcinoma. Using surface-enhanced laser desorption/ionization (SELDI) ProteinChip technology, we sought to identify a potentially diagnostic serum protein pattern that can serve as a reliable blood test for the diagnosis of esophageal adenocarcinoma. In addition, we sought to identify potential biomarkers for esophageal adenocarcinoma. METHODS: Whole serum was collected using standard techniques from subjects with a known diagnosis of esophageal adenocarcinoma as well as from subjects without any known esophageal disease. The samples were spotted onto a hydrophobic (H50) and immobilized metal affinity (IMAC30) chip surface and allowed to incubate. All samples were run in duplicate. After several washes, matrix was added and a mass range of 1500 to 30000 daltons was analyzed by SELDI-Time-of-Flight mass spectroscopy. Statistical analysis was performed using Biomarker Pattern Software (Bio-Rad Laboratories, Hercules, CA). RESULTS: For the H50 analysis, 3 peaks were identified that correctly diagnosed 42 of 43 cancers and 10 of 11 normals. For the IMAC30, 4 peaks were identified that correctly diagnosed 50 of 50 cancers and 10 of 10 normals. CONCLUSIONS: Serum proteomic pattern shows great promise in the diagnosis of esophageal adenocarcinoma. This technology may lead to the development of a noninvasive screening test as well as to the identification of potential novel biomarkers for esophageal adenocarcinoma.

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.

Safety of propofol administered by registered nurses with gastroenterologist supervision in 2000 endoscopic cases.

OBJECTIVES: Propofol has certain advantages over benzodiazepines plus narcotics as sedation for endoscopy. In a few centers, propofol has reportedly been used in endoscopic procedures and administered by nurses supervised by gastroenterologists without attendance by anesthesiologists or nurse anesthetists. METHODS: As part of our continuous quality improvement program, we prospectively recorded the doses of propofol and adverse reactions to the drug in our initial 2000 cases. In all cases propofol was administered by nurses who were supervised by gastroenterologists, with no involvement by an anesthesia specialist. RESULTS: The 2000 cases included 2222 procedures. There were five episodes of oxygen desaturation to <85%, four of which seemed to be related to excessive administration of propofol and were treated by brief (< 1 min) periods of mask ventilation. No patient required endotracheal intubation or hospital admission, or suffered long-term sequelae from propofol administration. There were no perforations in 977 colonoscopies. CONCLUSIONS: Propofol can be given safely by appropriately trained nurses under supervision by endoscopists. Technology that allows immediate detection of apnea would likely further improve its safety.

Efficacy and complications of argon plasma coagulation for hematochezia related to radiation proctopathy.

BACKGROUND: Endoscopic treatments effectively control bleeding caused by radiation proctopathy. The aims of this study were to determine the efficacy and side effects of argon plasma coagulation in the treatment of this type of bleeding. METHODS: Records of 21 consecutive patients in whom argon plasma coagulation was used to treat hemorrhagic radiation proctopathy were reviewed. RESULTS: Pharmacologic measures had been unsuccessful in 12 patients. Endoscopic treatment had been unsuccessful in 5 patients. All patients were anemic and 4 had received blood transfusions. The mean number of treatment sessions was 1.7, and 10 patients were successfully treated in single session. Rectal bleeding resolved within 1 month of the last treatment in 19 patients, usually on the day of the last procedure. Bleeding resolved 2 months after cessation of therapy in another patient. Short-term side effects occurred in 3 (14%) patients (rectal pain, tenesmus, and/or abdominal distention); long-term complications (rectal pain, tenesmus, diarrhea) developed in 4 patients (19%). CONCLUSIONS: Hematochezia caused by radiation proctopathy is effectively controlled by argon plasma coagulation, in some cases after a single treatment session. Treatment may result in protracted bowel symptoms.