Prospective Evaluation of Colorectal Polyps in 1,683 Consecutive Colonoscopies / 대한소화기내시경학회지

BACKGROUND AND AIMS: The colorectal polyp, particularly the adenoma, has been regarded as a precursor of cancer. The incidence of colorectal polyps has been reported at various rates according to investigation centers in foreign countries. In Korea, the incidence of colorectal polyps has been reported as very low according to the few reports, which was involved a few cases and were partial. Therefore, the aim of this study is to evaluate prospectively the incidence and the clinicopathologic features of colorectal polyps. METHODS: A colonoscope was inserted up into the cecum in 1,889 patients among 2,001 trials from Oct. 1996 to Aug. 1997 (success rate: 94.4%). Of the 1,889 full colonoscopies, the following were excluded; 1) referred patients with suspicious colorectal cancer or polyps, 2) patients with suspicious rectal cancer determined by rectal examination, 3) patients who had follow-up colonoscopy after a polypectomy or cancer surgery, and 4) patients who had periodic colonoscopy due to FAP or HNPCC. There were a total of 1,683 full colonoscopies in this study. The majority of the total cases involved a colonoscopy due to benign anal disease, irritable bowel syndrome, or routinechecks for health. RESULTS: There were 946 men (56.2%) and 737 women (43.8%). The mean age was 48.2 yrs (13~88 yrs) for men and 48.1 yrs (18~89 yrs) for women. 422 patients were found to have 645 colorectal polyps (1.52 polyps per patient). The incidence of polyps was 25.1% (32.0% for men, 16.1% for women) and increased after the 6th decade in men (44.0%) and in women (23.0%). 281 patients were found to have 426 colorectal adenomas. The incidence of adenomas was 16.6% (21.9% for men, 9.9% for women) and increased after the 6th decade, 32.0% in men, and 15.9% in women. Solitary polyps were present in 277 patients (65.6%) while 94 patients (22.3%) had two polyps and 51 patients (12.1%) had between 3 and 8 polyps. The polyp retrieval rate was 96.9%. There were 426 adenomas (66.0%), 75 hyperplastic (11.7%), 120 inflammatory (18.6%), and 24 miscellaneous (3.7%) polyps. Of the 426 adenoma, there were 397 tubular adenoma (93.2%), 18 tubulovillous adenoma (4.3%), 4 villous adenoma (0.9%), 6 in situ carcinoma (1.4%), and 1 invasive carcinoma (0.2%). 6 in situ carcinoma's were detected in tubular adenoma and 1 invasive carcinoma in tubulovillous adenoma. Of 645 polyps, the sessile type was 87.9%. The polyp size varied from 1 mm to 25 mm and 79.2% were under 5mm. Also, 85.7% of adenomas were sessile and 74.7% were under 5mm. 22.0% of polyps were located in rectum, 35.4% in sigmoid colon, 9.5% in descending colon, 13.3% in transverse colon, 19.8% in ascending colon and cecum. The distribution of adenoma was similar to that of polyp. 40.1% of adenoma showed moderate to severe dysplasia. CONCLUSIONS: This study revealed that the incidence of polyp in Korea was higher than that in previous reports and 42.6% of polyps were proximal to rectosigmoid colon. Therefore, we suggest that we should try to detect and remove colorectal polyps by more active colonoscopy.

Effect of Lidocaine Injected on Lower Rectal Submucosa During Hemorrhoidectomy under Caudal Anesthesia

BACKGROUND/AIMS: The caudal anesthesia for anal surgery is simple and effective. Also, it is relatively safe because there is no headache or other neurologic complications. But, during the operation under caudal anesthesia, the unwanted symptoms such as lower abdominal pain or hypotensive symptoms were experienced in some patients. These unwanted symptoms may occur due to anal and lower rectal dilatation. The precise mechanism is unknown. But we speculated that some sensory nerve endings in rectal submucosa may be involved in this mechanism. So, we think that it is possible to prevent or reduce these symptoms if we block these sensory nerve endings effectively with local anesthetics. Therefore, the aim of this study is to see whether the locally injected lidocaine can reduce or prevent the unwanted symptoms during anal surgery under caudal anesthesia. METHODS: There were 100 consecutive patients in this study who had hemorrhoidectomy with Jack-knife position under caudal anesthesia at our clinic. We divided evenly these 100 patients into two groups, injection and control groups(in each group, 50 patients were included.). In injection-group, We injected 10 cc(100 mg) of 1% lidocaine solution cir cumferentially into the lower rectal submucosa at the beginning of the operation. In control-group, we did not inject lidocaine solution initially, but the lidocaine injection was done during the operation in the same manner in the injection-group if the severe unwanted symptoms occurred. We used Parks-type retractor to dilate the anus and recorded the patient,s complaints. RESULTS: In injection-group, male to female ratio was 33:17, mean age was 42.1 years(20~69) and mean operation time was 38.3 minutes(15~80). In control-group, male to female ratio was 25:25, mean age was 43.7 years(17~65) and mean oeration time was 38.5 minutes(15~80). Lower abdominal pain was present in 11 patients(22%) among injection-group and in 37 patients(74%) among control-group(p=0.000). Hypotensive symptoms such as nausea, vomiting, sweating and dizziness were present in 1 patient(2%) among injection-group and in 8 patients(16%) among control-group(p=0.014). We injected lidocaine solution into lower rectal submucosa during the operation in 18 patients with severe symptoms among control-group. The effect of the injected lidocaine solution in 18 control patients was good in 13(72%) and fair in 5(28%). With regard to factors influencing the occurrence of symptoms, there was a tendency of higher occurrence in male, the younger-aged and the longer-operation groups. CONCLUSION: The lower rectal submucosal lidocaine injection reduced the unwanted symptoms such as lower abdominal pain and hypotensive symptoms during the anal surgery under the caudal anesthesia.

Sigmoidoscopy, is it Enough as a Screening Tool? -Undetectable colorectal adenomas by sigmoidoscopy-

BACKGROUND: It is generally accepted that most colorectal cancers develop from adenomas, so the detection and removal of them can reduce the incidence of colorectal cancers. Sigmoidoscopy is the effective tool for detecting and removing adenomatous polyps in the rectosigmoid region, but its major limitation is that sigmoidoscopy alone can not detect considerable portion of colorectal adenomas. METHODS: From October, 1996 to August, 1997, we performed 2017 sigmoidoscopies and 1683 colonoscopies. We analysed the anatomical distribution of adenomas and compared the detection rate of adenomas between two groups. In 32 cases, adenomas detected by sigmoidoscopy were followed by colonoscopy in less than 2 months. RESULTS: We found 125 cases of adenomas in 2017 sigmoidoscopies and 281 cases of adenomas in 1683 colonoscopies. In 281 cases of adenomas found by colonoscopy, 151 cases had rectosigmoid adenomas only and 25 cases had rectosigmoid and proximal adenomas, 105 cases had proximal adenomas only. The detection rate of adenomas by sigmoidoscopy was significantly lower than that by colonoscopy in the rectosigmoid region(6.1% vs. 10.5%, p=0.002). In 32 cases of adenomas found by sigmoidoscopy that were followed by colonoscopy, 7 cases of proximal adenomas and 6 cases of additional rectosigmoid adenomas were detected. CONCLUSION: Sigmoidoscopy cannot detect adenomas in the proximal colon beyond the sigmoid, it also can miss a significant portion of adenomas in the rectosigmoid.