Colon cancer screening. Sigmoidoscopy or colonoscopy.

Colorectal cancer is a common neoplasia with high morbidity and mortality. With endoscopy it is possible to identify its precursor lesion, the adenoma, and early localized cancer. Early detection and removal of adenomas can reduce the incidence and mortality of this disease. Studies using fecal occult blood testing (FOBT) and sigmoidoscopy for screening asymptomatic patients demonstrate a reduction in mortality from colorectal cancer. Colonoscopy, however, has the highest yield for detecting polyps. Most authorities and organizations now recommend screening the asymptomatic population over age 50 for colorectal neoplasia. The estimated cost of colon cancer screening is well within the benchmark figure of $40,000 per year of life saved, which is considered by the government to be cost effective. Controversies still exist regarding which colon cancer screening strategy is the most sensitive, specific, acceptable to the population, and cost effective. The American Cancer Society recommends a combination of FOBT and flexible sigmoidoscopy, but some experts believe that a one-time colonoscopy at age 60 may be a more cost-effective method. If the costs of colonoscopy are reduced, it is more cost effective than other techniques. Colonoscopy also may help to stratify at-risk patients, and those with negative initial colonoscopy may not need further screening. Advances in molecular biology may provide markers for screening or identifying people who are at high risk for colorectal neoplasia. This development may allow screening to be directed at high-risk groups.

Gastric outlet obstruction.

Acquired gastric outlet obstruction is more commonly owing to malignancy than ulcer disease. Endoscopy is the preferred method for diagnosis. Surgical palliation for malignant disease has poor results and high rates of morbidity and mortality. Initial experiences with endoscopic palliation with expandable metallic endoprostheses appear promising. Peptic ulcer-induced gastric outlet obstruction can be treated safely with endoscopic balloon dilation. About 65% of patients have sustained symptom relief, but many require more than one dilation session. Outcomes may be improved with effective ulcer therapy with acid reduction and eradication of H. pylori. Surgery is associated with significant morbidity and mortality and should be reserved for endoscopic treatment failures.

Sigmoidoscopy training for nurses and resident physicians.

Five gastrointestinal nurses (three licensed practical nurses and two registered nurses) and five resident physicians were enrolled in a sigmoidoscopy training protocol. Patients referred for a screening sigmoidoscopy were randomized to have the procedure performed by a nurse or a resident. Objective criteria for proficiency were depth of endoscope insertion, procedure time, and identification of anatomic landmarks and pathologic lesions; subjective criteria included thoroughness and the need for assistance. Four nurses and all of the residents were deemed proficient at a mean of 20 procedures in both groups. One registered nurse did not achieve proficiency after 35 procedures; this determination was based on subjective criteria. Insertion depth and identification of normal anatomy improved with experience. Trainees missed 1.4% of pathologic lesions, and no complications were observed. Nurses can be trained to perform a screening sigmoidoscopy in a safe and effective manner, with results similar to those for doctors.

Dilation of refractory pancreatic duct strictures: the turn of the screw.

BACKGROUND: Endoscopic pancreatic ductal drainage may improve pain from chronic pancreatitis but stricture dilation may be technically difficult. METHODS: Eight patients with refractory pancreatic strictures had dilation with a Soehendra stent retriever. Each had sphincterotomy, guidewire placement, stent retriever dilation to 7F to 10F, and stenting for 6 to 12 months. RESULTS: All procedures were successful and 1 (13%) was complicated by mild pancreatitis. The mean follow-up was 21 months. Each patient had substantial pain relief with patent stents in place, but 7 (88%) relapsed with stent occlusion or removal. Four (50%) patients underwent surgery with excellent results. However, endoscopic therapy alone resulted in just modest benefits or pain recurrence in 3 (38%) and persistent relief in only 1 (13%). CONCLUSIONS: The Soehendra stent retriever is effective as a dilating device for pancreatic strictures resistant to conventional dilation. However, substantial symptom relief may persist only while patent stents are in place.

Endoscopic therapy for stenosis of the biliary and pancreatic duct orifices.

BACKGROUND: Manipulation of the duodenal papilla may lead to symptomatic stenosis of the orifices of bile duct, main pancreatic duct or accessory pancreatic duct. METHODS: Seventeen patients with stenosis of the orifice (bile duct 7, bile duct/main pancreatic duct 7, accessory pancreatic duct 3) underwent sphincterotomy and/or dilation and stent placement for a median of 140 days (range 30 to 1080 days). Patients were interviewed at a median of 720 days (range 120 to 990 days) after removal of the final stent. RESULTS: Median age was 50 years (range 17 to 68 years); 78% were women. The etiology of stenosis of the orifice was sphincterotomy in 8, sphincteroplasty in 7 and papillectomy in 2 patients. Indications for treatment were abdominal pain (100%), dilated bile duct and/or main pancreatic duct (14 patients) and pancreas divisum (3 patients). Sixty procedures (median 4 per patient) were performed with mild morbidity (hospital stay less than 3 days) in 17% of procedures and 35% of patients. Symptoms improved in 100%, 57% and 33% of patients with bile duct, bile duct/main pancreatic duct and accessory pancreatic duct, respectively. Surgery was ultimately needed in 3 (43%) patients with bile duct/main pancreatic duct and 2 (67%) with accessory pancreatic duct stenosis. CONCLUSIONS: Endoscopic therapy successfully relieves pain due to biliary stenosis of the orifice but less frequently relieves pain due to pancreatic stenosis of the orifice.

Argon laser therapy for hemorrhagic radiation proctitis: long-term results.

In chronic radiation proctitis bleeding occurs from mucosal friability and neovascular telangiectasias. Fourteen patients with bleeding from chronic radiation proctitis underwent endoscopic argon laser therapy at 4 to 8 W. The goal of treatment was obliteration of all telangiectasias. The average follow-up was 35 months. Of the 51 procedures, 48 (94%) were performed on outpatients with enema preparation and little or no sedation. A median of three procedures was performed per patient, with two sessions required for initial control of bleeding. Ten patients (71%) required maintenance therapy for recurrent bleeding from telangiectasias that developed after initial therapy. The mean interval between maintenance sessions was 7 months. No immediate or late complications occurred.

Gastroenterology consultations from the internal medicine physician's perspective.

OBJECTIVE: To examine the patterns of use of gastroenterology consultations by internal medicine physicians. DESIGN: A survey of licensed physicians in the three metropolitan areas in Arizona where gastroenterologists are available. The physicians were asked how likely they were to obtain gastroenterology consultations for a variety of different gastrointestinal illnesses. Comparisons between groups were done with chi-square analysis. MEASUREMENTS AND MAIN RESULTS: Forty-six percent of the physicians responded. The majority of respondents believed that esophagogastroduodenoscopy and colonoscopy should be available without gastroenterology consultation (65% and 64%, respectively). Physicians in practice more than ten years were less prone to request consultation for gastrointestinal complaints that were likely to result in endoscopic procedures, such as the diagnosis of peptic ulcer disease or inflammatory bowel disease, or guaiac-positive stool. Internal medicine residents were more likely to seek consultations for both endoscopic and cognitive gastrointestinal complaints. Internal medicine residents were far more likely to request gastroenterology consultations for most patients with upper-gastrointestinal-tract bleeding (91% vs. 60%, p less than 0.001) and lower-gastrointestinal-tract bleeding (65% vs. 22%, p less than 0.0001) than were internists practicing more than ten years. CONCLUSIONS: The majority of internal medicine physicians would like to order endoscopic procedures without gastroenterology consultations, much as they order radiography. Recently trained physicians are far more likely to request consultants for procedure-related problems.

Genetics of colon cancer: impact of inheritance on colon cancer risk.

The genes that are mutated in two of the rare syndromes of hereditary colon cancer were recently identified, and genetic diagnosis is already possible in some cases. Acquired mutations of these same genes also appear to be important in sporadic colon cancers. Familial clustering of sporadic cases is common and may likewise arise from inherited susceptibility. Screening strategies for both the rare syndromes and the common cases of colon cancer with familial risk have been suggested. Certain clinical features allow stratification of colon cancer risk among common cases. It is anticipated that continued genetic investigation will result in more precise screening and improved diagnostic and therapeutic options for colon cancer.

Poor results with percutaneous endoscopic jejunostomy.

A percutaneous endoscopic gastrostomy was placed in 20 malnourished patients to serve as a conduit for passage of a percutaneous endoscopic jejunostomy (PEJ) catheter for delivery of alimentation directly into the small bowel. Serious complications occurred in 95% of the patients and 50% of the subjects died. Aspiration was the most common adverse event and accounted for all deaths. Ten of 15 subjects (67%) treated with a PEJ to prevent aspiration continued to aspirate after the catheter was placed. PEJ tube failures were documented in 14 subjects (70%) and occurred because of occlusion, leakage, malposition, extrusion, cracking, kinking, or rupture of the catheter. These problems rendered the PEJ nonfunctional 18% of the time. Large manpower and resource investments were required to manage the PEJ and its complications. Our results suggest that enteral feeding through a PEJ does not prevent aspiration. Serious PEJ-related morbidity (95%), mortality (50%), and catheter failures (70%) occur. Refinements in methodology and catheter design will be required before additional use of this technique can be recommended.

KTP laser therapy for bleeding from chronic radiation proctopathy.

BACKGROUND: Endoscopic laser photocoagulation is commonly used to treat bleeding from the neovascular lesions of chronic radiation proctopathy. The KTP laser is an Nd/YAG-driven unit that emits light with a wavelength of 532 nm. This wavelength of energy is absorbed by hemoglobin and penetrates tissue to a depth of only 1 to 2 mm. METHODS: Twenty-three patients were treated with KTP laser and followed for a median of 29 months (range 5 to 51 months); 21 had received radiation for prostate cancer and 2 for uterine cancer. The median age was 77 years (range 68 to 87 years). A median of 2 sessions (range 1 to 5 sessions) was performed using 4 to 10 Watts of power and a median energy of 816 Joules per session (range 204 to 2430 Joules). RESULTS: After treatment there was a significant reduction in the frequency (p = 0.0005) of bleeding, increase in hematocrit level (p < 0.0001), improvement in activities of daily life (p = 0.01), and a reduction in use of health care resources (p < 0.0001). There was a trend toward decreased use of iron supplements (11 to 4 patients) and transfusions (4 to 0 patients). Two patients (9%) developed rectal ulcers after treatment. CONCLUSIONS: KTP laser photocoagulation is a safe and effective therapy for bleeding from chronic radiation proctopathy that improves activities of daily living and reduces use of health care resources.

Prevalence and malignant potential of colorectal polyps in asymptomatic, average-risk men.

Screening colonoscopy was performed on 119 asymptomatic elderly men with no other risk factors for colonic neoplasms. Ninety adenomas were detected in 49 (41%) subjects. Mean adenoma size was 6.5 mm, with 83 (92%) less than or equal to 10 mm. Forty-nine (54%) adenomas were located proximal to the splenic flexure, and 17 (19%) were classified as tubulovillous or villous. Moderate- to high-grade dysplasia was found in 29 (32%) adenomas and was associated with larger size (p less than 0.0001) and villous architecture (p = 0.0038). Two subjects harbored adenomas with invasive cancer. Seventy-one hyperplastic polyps were found in 40 (34%) subjects. The mean size of hyperplastic polyps was 3.4 mm, and 64 (90%) were located in the left colon. We conclude that, in this population, adenomas are common lesions that are frequently small. However, substantial proportions of these adenomas may be at risk for malignant degeneration due to the presence of villous architecture and higher grades of dysplasia. Because adenomas and hyperplastic polyps are endoscopically indistinguishable, all polyps found at endoscopy should be removed or ablated.

Monitoring of blood pressure and heart rate during routine endoscopy: a prospective, randomized, controlled study.

Six hundred and eighteen patients were randomized to have automated cardiovascular monitoring or clinical observation during routine endoscopy. Hemodynamic parameters were recorded at 3-min intervals before, during, and after the procedure. Upper gastrointestinal endoscopy resulted in an increased heart rate (HR), while colonoscopy caused a decreased blood pressure (BP) and HR. Hemodynamic aberrations occurred in 71% of monitored patients, including hypotension 6%, hypertension 30%, bradycardia 26%, and tachycardia 32%. Only one-third of the hypotensive episodes were recognized as aberrations, and therapeutic intervention did not improve outcome. No monitored or control patient had an adverse result. Certain hemodynamic changes were directly correlated with the baseline BP or HR and associated with the presence of coronary artery disease, particular medicines with cardiovascular effects and longer procedure duration. We conclude that automated monitoring during routine endoscopy unmasks frequent hemodynamic aberrations that are clinically insignificant. Routine monitoring during endoscopy does not improve outcome.

The sentinel hyperplastic polyp: a marker for synchronous neoplasia in the proximal colon.

We prospectively screened 129 asymptomatic subjects (mean age 64 yr) with flexible sigmoidoscopy. Colonoscopy was performed at a later date, regardless of the sigmoidoscopic result. Our intent was 1) to establish the prevalence of proximal neoplasms in patients with and without hyperplastic polyps within reach of the 60-cm sigmoidoscope and 2) to determine whether a distal (sentinel) hyperplastic polyp predicts the presence of synchronous neoplastic polyps higher up in the colon. Our results show that 15% of asymptomatic adult subjects without polyps on sigmoidoscopy have adenomas in proximal colonic segments that can be diagnosed only by colonoscopy. By comparison, proximal neoplasms were detected in 32% (p less than 0.05) and 37% (p less than 0.05) of patients when hyperplastic or adenomatous polyps, respectively, were present on the sigmoidoscopic examination. This finding suggests that a distal (sentinel) hyperplastic polyp by itself may be a marker for neoplastic polyps in proximal colonic segments. Also, the "index" adenoma and "sentinel" hyperplastic polyp may be equivalent for predicting the presence of proximal neoplasms. The observed detection rates for these polyps were both significantly higher than expected when compared to patients who did not have polyps in the distal colon or rectum. If these results can be confirmed by a larger prospective trial, then full colonoscopy for detection of proximal neoplasms may be indicated when either an index adenoma or sentinel hyperplastic polyp is detected by sigmoidoscopy.

The gastroenterologist: physician or technician?

Concern exists about perceived overuse of gastrointestinal endoscopic procedures. To determine the portion of the current practice of gastroenterology that is procedure related or purely cognitive, we compared 303 consultations from two practices. One-hundred and eighty-seven patients were in a Veterans Affairs Medical Center and 116 in a private group practice. Sixty-five percent of the consultations resulted in an endoscopic procedure. Patients referred for abnormal barium studies (100%), percutaneous endoscopic gastrostomy placement (97%), and gastrointestinal bleeding (83%) were most likely to have a procedure. Sixty-nine percent of consultations from medical specialties had endoscopy compared with 44% from surgical specialties and 45% from other specialties. There were no differences noted between the two practices. We conclude that gastroenterology is predominantly a procedure-oriented subspecialty. Procedures are performed most commonly on patients referred for conditions that are likely to require endoscopic biopsy or therapeutics and on patients referred from medical specialists.

Perspectives of chromo and magnifying endoscopy: how, how much, when, and whom should we stain?

The goal of every routine endoscopy in the gut is the early diagnosis of malignant and premalignant changes of the mucosa. Chromo- and magnifying endoscopes are exciting new tools and offer detailed analysis of the colonic mucosal surface and pit pattern architecture. This review summarizes recent advances in endoscopic characterization of colorectal lesions using magnification endoscopy and chromoendoscopy. Surface analysis of the colon using chromoendoscopy allows a prediction between non-neoplastic and neoplastic lesions with high specificity. The precise delineation of the borders and a more detailed macroscopic analysis of the lesions are further advantages. In particular, flat adenomas and early depressed cancers are now more frequently recognized in western countries suggesting that significant lesions were overlooked by conventional endoscopy in the past. Furthermore, chromoendoscopy can be used in a targeted fashion to screen for sporadic adenomas. Finally, in surveillance colonoscopy, patients with long-standing ulcerative colitis have a valuable benefit if targeted biopsies are performed to detect intraepithelial neoplasias after pan-chromoendoscopy with methylene blue. Although there is a long learning curve, chromoendoscopy should thus belong to every endoscopists armamentarium. However, detailed knowledge about the technique, dyes, and specific staining patterns are mandatory before the yield of screening or surveillance colonoscopy can be increased. The new detailed images seen with magnifying chromoendoscopy are unequivocally the beginning of a new era where new optical developments will allow a unique look on cellular structures.

Colorectal cancers of rare histologic types compared with adenocarcinomas.

PURPOSE: To examine clinical characteristics of colorectal cancers of rare histologic types compared with adenocarcinomas. METHODS: Review of a population-based registry with complete ascertainment. RESULTS: There were 7,422 colorectal cancers, 4,900 (66 percent) colonic and 2,522 (34 percent) rectal. Two hundred fifty-five cancers (3 percent) were of nonadenocarcinoma varieties including 75 (33 percent) squamous, 74 (33 percent) malignant carcinoids, 37 (16 percent) transitional cell-like, 25 (11 percent) lymphomas, 9 (4 percent) sarcomas, and 2 (0.9 percent) melanomas. Sixty (1.2 percent) of the colon cancers occurred in the appendix, and proportionately more carcinoids accounted for these tumors. Compared with adenocarcinomas, colonic and rectal carcinoids and colonic lymphomas accounted for a larger proportion of cancers in the younger age groups. The elderly had proportionately fewer colonic carcinoids. Colonic carcinoids, rectal squamous-cell cancers, and rectal transitional cell-like cancers were more common in women. Colonic lymphomas had a worse prognosis than adenocarcinomas. Survival was better with colonic and rectal carcinoids and rectal transitional cell-like cancers than with adenocarcinomas. CONCLUSIONS: Colorectal cancers of histologic varieties other than adenocarcinoma have distinctive epidemiologic and clinical traits.

Small bowel cancer: epidemiological and clinical characteristics from a population-based registry.

OBJECTIVES: Data on small bowel cancers are scarce, and are derived primarily from hospital series. Our aim was to examine the epidemiological and clinical characteristics of these rare cancers. The database is population-based registry with complete ascertainment. It is thus free of the selection bias innate to hospital series. METHODS: Review of the Utah Cancer Registry for all small bowel cancers from 1966 through 1990. For comparison, other cancers were reviewed for incidence and relative survival rates. RESULTS: There were 328 small bowel cancers, including 136 (41%) carcinoids, 80 (24%) adenocarcinomas, 72 (22%) lymphomas, 36 (11%) sarcomas, and four (1%) unclassified. The overall age-adjusted incidence per 100,000 was 1.4 for small bowel cancers compared to 35.7 for colorectum and 92.9 for breast. Small bowel cancers occurred most frequently in the sixth and seventh decades of life, and were more common in men. Carcinoids, lymphomas, and sarcomas occurred in order of decreasing frequently in the ileum, jejunum, and duodenum; the reverse was true for adenocarcinomas. Distant metastases occurred in 35 (27%) carcinoids, 14 (28%) adenocarcinomas, 17 (26%) lymphomas, and 10 (33%) sarcomas. Surgery was the primary form of therapy in 108 (79%) carcinoid patients, 80 (49%) adenocarcinoma patients, 52 (72%) lymphoma patients, and 26 (72%) sarcoma patients. The overall 5-year relative survival rate for small bowel cancers was 54%; 83% for carcinoids, 25% for adenocarcinomas, 62% for lymphomas, and 45% for sarcomas. Overall survival, compared to other cancer sites, was surpassed only by cancers of the prostate, breast, and colorectum. CONCLUSIONS: Small bowel cancers consist of several types of rare tumors, each with unique characteristics. The overall prognosis is better than for most common cancers.

Flexible sigmoidoscopy may be ineffective for secondary prevention of colorectal cancer in asymptomatic, average-risk men.

Asymptomatic men (N = 114) 50 years of age or older had screening for colorectal neoplasia with flexible sigmoidoscopy followed by colonoscopy regardless of the sigmoidoscopic result. Our study objective was to determine the prevalence of patients having isolated adenomatous polyps in a proximal colonic segment in the absence of a distal index neoplasm within reach of the sigmoidoscope. Through the combined use of sigmoidoscopy and colonoscopy, adenomatous polyps were detected in 47 of 114 individuals (41%). A total of 88 adenomas was found. Seventeen patients had isolated neoplasms in proximal colonic segments in the absence of distal adenomas. These patients represented 15% of screened subjects (17 of 114) and 20% of individuals who lacked adenomas on sigmoidoscopy (17 of 84). The majority of proximal neoplasms were small (less than 1.0 cm), tubular adenomas. Flexible sigmoidoscopy may be ineffective for screening asymptomatic men for neoplasia. However, it remains to be determined if a 20% miss rate (for those with a normal sigmoidoscopic examination) is significant and whether small proximal adenomas are worth finding.

Colonic polyps in an unselected population: prevalence, characteristics, and associations.

OBJECTIVES: To provide a proctosigmoidoscopic review of a very large set of unselected control subjects, providing an unbiased view of colonic polyps in the general population. METHODS: Sigmoidoscopic data from 406 sequentially recruited subjects were analyzed. Participation rates were over 85%, and subjects were thus free of the usual selection bias. RESULTS: Thirty-eight percent of screened individuals were found to have distal colonic polyps. Adenomas were found in 12%, and hyperplastic polyps were found in 30% of screened individuals. Adenomas were more prevalent in males and in older individuals. Hyperplastic prevalence did not differ significantly by gender or age. Synchronous adenomatous and hyperplastic polyps occurred in 3% of screened individuals, but these lesions were not associated. CONCLUSIONS: Distal colonic adenomatous and hyperplastic polyps are very common in the general population and are not associated. The high frequency of these polyps raises questions about the feasibility of biopsy for all polyps, and suggests that further study is needed to determine the appropriate indications for subsequent colonoscopy.

Endoscopic balloon dilation for ulcer-induced gastric outlet obstruction.

OBJECTIVE: To determine the safety and efficacy of endoscopic balloon dilation for ulcer-induced gastric outlet strictures. METHODS: Review of the cumulative experience from two institutions involving 30 patients who underwent endoscopic balloon dilation for peptic ulcer-induced gastric outlet obstruction. Follow-up was by standardized interview at a mean of 15 months (range 4-28 months). RESULTS: Symptoms occurred for an average of 6 months before dilation and included weight loss, epigastric pain, nausea, vomiting, early satiety, bloating, and anorexia. Gastric outlet strictures had a median diameter of 6 mm (range, 0-10 mm). Ten (33%) patients had active ulcers. Six-millimeter to 18-mm (median 15-mm) balloons were inflated a median of 2 times (range 1-4 times) for a median of 60 s (range 30-180 s). Fifty-one procedures (1.7/patient) were performed; 20 (67%) patients had one treatment and 10 (33%) had multiple treatments. Twenty-four (80%) patients achieved sustained symptom relief, 17 of 20 having a single procedure and 7 of 10 required multiple sessions. Dilation failed in 4 (13%) patients with long duodenal strictures. Two (6.7%) patients dilated to 18 mm suffered perforation. Both recovered uneventfully after surgery. CONCLUSIONS: Endoscopic balloon dilation is safe and effective for most patients with ulcer-induced gastric outlet obstruction.