Emad Y. Rahmani

Colonoscopic miss rates of adenomas determined by back-to-back colonoscopies

BACKGROUND & AIMS The miss rate of colonoscopy for neoplasms is poorly understood. The aim of this study was to determine the miss rate of colonoscopy by same day back-to-back colonoscopy. METHODS Two consecutive same day colonoscopies were performed in 183 patients. The patients were randomized to undergo the second colonoscopy by the same or a different endoscopist and in the same or different position. RESULTS The overall miss rate for adenomas was 24%, 27% for adenomas < or = 5 mm, 13% for adenomas 6-9 mm, and 6% for adenomas > or = 1 cm. Patients with two or more adenomas at the first examination were more likely than patients with no or one adenoma detected at the first examination to have one or more adenomas at the second examination (odds ratio, 3.3; 95% confidence interval, 1.69-6.46). Right colon adenomas were missed more often (27%) than left colon adenomas (21%), but the difference was not significant. There was evidence of variation in sensitivity between endoscopists, but significant miss rates for small adenomas were found among essentially all endoscopists. CONCLUSIONS Using current colonoscopic technology, there are significant miss rates for adenomas < 1 cm even with meticulous colonoscopy. Miss rates are low for adenomas > or = 1 cm. The results suggest the need for improvements in colonoscopic technology.

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

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

Variable pathologic interpretation of columnar lined esophagus by general pathologists in community practice

BACKGROUND Pathologic interpretation of biopsy specimens of columnar lined esophagus guides subsequent endoscopic surveillance and/or surgical intervention. The aim of this study was to evaluate pathologic interpretation of columnar lined esophagus by general pathologists in community practice. METHODS Five histologic slides representing different types of columnar lined esophagus were submitted for review by 20 randomly selected general pathologists in community practice. There were three cases with intestinal metaplasia (one with no dysplasia, one with low-grade dysplasia, and one with high-grade dysplasia) and two cases of gastric metaplasia (one fundic-type and one cardia-type). RESULTS High-grade dysplasia was identified as such by 30% of pathologists and was called invasive adenocarcinoma by 20%, low-grade dysplasia by 30%, and moderate dysplasia by the remaining 20%. Low-grade dysplasia was identified as such by 35% of pathologists and was called high-grade dysplasia by 20%, moderate dysplasia by 20%, and no dysplasia by 25%. Specialized columnar epithelium with no dysplasia was identified as such by 35%, called low-grade dysplasia by 35%, moderate dysplasia by 15%, indeterminate for dysplasia by 10%, and invasive adenocarcinoma by 5%. Gastric metaplasia without specialized columnar epithelium was identified as Barretts esophagus in 38% of cases. CONCLUSIONS Pathologic interpretation of columnar lined esophagus by community pathologists may be subject to marked interobserver variation. The term Barretts esophagus is often used to describe columnar lined esophagus without goblet cells. Because this finding is not clearly associated with an increased risk of cancer, these data support recent suggestions that the term Barretts esophagus be abandoned. Interpretations of both high-grade and low-grade dysplasia should be considered for review by experts in esophageal pathology.

Neoplasia distal to the splenic flexure in patients with proximal colon cancer

BACKGROUND Current American Cancer Society recommendations are that persons aged 50 years or older undergo screening flexible sigmoidoscopy every 3 to 5 years. In clinical practice, persons with adenomas at sigmoidoscopy are generally referred for full colonoscopy. However, cancers proximal to the splenic flexure may not be accompanied by neoplasia distal to the splenic flexure. METHODS In order to estimate how often screening flexible sigmoidoscopy would be negative in persons with proximal cancer, we retrospectively reviewed 2053 consecutive colorectal cancer cases diagnosed from 1988 to 1994. Seven hundred ninety-nine (38.9%) had tumors proximal to the splenic flexure. We selected 358 study cases based on full colonoscopy performed and the colonoscopy reports available. RESULTS Colonoscopy demonstrated distal adenomas in 77 cases (21.5%): 29 (8.1%) had hyperplastic polyps only, 4 (1.1%) had synchronous cancer, and 248 (69.3%) had no distal polyps. In this population, 77.4% of patients with proximal colon cancer had no distal neoplasia. We estimate that 30% of all patients with colorectal cancer would have a negative screening flexible sigmoidoscopy. CONCLUSIONS Prospective evaluation of colonoscopic findings in persons with proximal cancers is needed. Ongoing evaluation of colonoscopy as a general screening test is appropriate.

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.

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.

3539 Photodynamic therapy for ablation of esophageal high grade dysplasia and superficial cancer.

BACKGROUND: High-grade dysplasia (HGD) and T1 superficial esophageal carcinoma (SEC) is relatively uncommon. However, Barrett s epithelium (BE) surveillance and widespread use of upper endoscopy have increased their recognition. Photodynamic therapy (PDT) has emerged as a new modality to ablate superficial neoplastic tissue including SEC in patients who decline surgery or are not surgical candidates. PATIENTS: Twenty-five patients (18M) with HGD (11 patients) and SEC (14 patients) were treated with PDT. Mean age was 67 (range 40-86), 24 were white and one was black. There were two squamous HGD. Mean length of BE was 5 cm. All patients either refused or were not candidates for surgical resection. METHODS: Photofrin® (porfimer sodium) was used. Light was delivered by a 1, 2.5 or 5 cm diffuser. Light dose was 175-200 J/cm for the HGD and 250-300 J/cm for the SEC. Argon plasma coagulation (APC) was used to ablate the residual BE during follow up period. Patients were maintained on proton pump inhibitors and were followed for 3-19 months (mean 12) with endoscopy and endoscopic ultrasound (EUS). Three patients (12%) had two PDT procedures. RESULTS: Endoscopic BE ablation was achieved in all patients (100%) using PDT + APC. Only three patients (3/25, 12%), two with SEC and one HGD developed recurrence. The first showed early recurrence and underwent surgical resection. The second patient had residual cancer and is scheduled for repeat PDT. The third patient had a positive celiac lymph node involvement at one-year EUS follow up and underwent chemoradiation therapy. Stricture requiring multiple dilations developed in five patients (5/25, 20%). CONCLUSION: PDT+ APC along with gastric acid control provides an effective endoscopic therapy to eliminate HGD and SEC. SUMMARY: 1- PDT is effective in ablation of HGD+ SEC with minimal morbidity and no mortality. 2-long term data is needed. 3- Routine post PDT EUS may detect early lymph node metastasis.