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Biomedical subjects

A M Vernava

Publications and source records attributed to A M Vernava.

At least 19 recordsLinked to original sources

Role of Mycobacterium paratuberculosis in Crohn's disease: a prospective, controlled study using polymerase chain reaction.

PURPOSE: Mycobacterium paratuberculosis has been proposed as a causative agent in patients with Crohn's disease. The purpose of this study was to determine whether M. paratuberculosis was present in tissue from patients with Crohn's disease in a defined geographic area. METHODS: We prospectively evaluated, using polymerase chain reaction and culture, whether M. paratuberculosis was present in 44 specimens (37 from intestinal mucosal biopsies and 7 from surgical resections) from patients with Crohn's disease, ulcerative colitis, or normal colonic mucosa. RESULTS: Of the 25 specimens tested from the 21 Crohn's patients, only 1 positive specimen was noted, whereas the 8 specimens from the 5 ulcerative colitis patients and the 11 specimens from the 11 control patients failed to demonstrate a positive result with polymerase chain reaction. Cultures of all specimens revealed no growth of M. paratuberculosis. CONCLUSION: M. paratuberculosis was only rarely detected in biopsy or surgical specimens from patients with Crohn's disease. These results do not support a common causative role of M. paratuberculosis in Crohn's disease.

Adolescent

Outcome after proctectomy for rectal cancer in Department of Veterans Affairs Hospitals: a report from the National Surgical Quality Improvement Program.

OBJECTIVE: To define risk factors that predict adverse outcomes after proctectomy for cancer in Department of Veterans Affairs Medical Centers. SUMMARY BACKGROUND DATA: Accurate presurgical assessment of the risk of perioperative complications and death is important in planning surgical therapy. METHODS: The National VA Surgical Quality Improvement Program contains prospectively collected and extensively validated data on >287,000 patients. All patients undergoing proctectomy for rectal cancer from 1991 to 1995 who were registered in this data base were selected for study. Independent variables examined included 68 presurgical and 12 intraoperative clinical risk factors; dependent variables were 21 specific adverse outcomes. Stepwise logistic regression analysis was used to construct models predicting 30-day morbidity rates for each of the 10 most common complications and the 30-day mortality rate. RESULTS: Five hundred ninety-one patients were identified; 467 (79%) underwent abdominoperineal resection and 124 (21%) were treated with sphincter-saving procedures. Thirty percent of patients had one or more complications after proctectomy. Prolonged ileus, urinary tract infection, pneumonia, and deep wound infection were the most frequently reported complications. The 30-day mortality rate was 3.2% (19 deaths). For most complications, 30-day mortality rates were significantly higher for patients with complications than for those without. Thirty-day mortality rates for several complications exceeded 50%: cardiac arrest requiring cardiopulmonary resuscitation, deep venous thrombosis or thrombophlebitis, coma lasting >24 hours, acute renal failure, cerebrovascular accident, and pulmonary embolism. Four presurgical factors predicted a high risk of 30-day mortality in the logistic regression analysis: elevated blood urea nitrogen level, impaired sensorium, low serum albumin concentration, and partial thromboplastin time < or =25 seconds. CONCLUSIONS: Mortality rates after proctectomy in VA hospitals are comparable to those reported in other large series. Most postsurgical complications are associated with an increased 30-day mortality rate. Elevated presurgical blood urea nitrogen level, impaired sensorium, low serum albumin concentration, and partial thromboplastin time < or =25 seconds predict a high risk of 30-day mortality.

Adult

Chronic constipation--is the work-up worth the cost?

BACKGROUND: Chronic constipation can be a disabling condition that may require colectomy. Evaluation has been included as a way to select appropriate patients for colectomy and may also be extensive, unrevealing, and costly. AIMS: This study was undertaken to determine the cost and use of evaluation and outcome of patients with chronic constipation. METHODS: Patients with chronic constipation were reviewed for severity of symptoms, diagnostic studies performed, treatment, and outcome. The costs of the diagnostic studies were determined at our institution. Fifty-one patients were identified with chronic constipation; all were referred by other physicians. Mean age was 54 (range, 21-81) years; 59 percent were females. Average number of bowel movements per week was two (range, 0-4), and average duration of symptoms was five years (range, 1-20). Forty-three of 51 (84 percent) colonoscopies or barium enemas were normal. Thirteen of 51 (25 percent) colonic transit studies were abnormal. Twenty-six of 51 (51 percent) patients underwent defecography; 12 (46 percent) were abnormal. Thirty-seven of 51 (74 percent) underwent anal manometry; 5 (14 percent) were abnormal. One of 18 (6 percent) rectal biopsies demonstrated Hirschsprung's disease. Overall, 8 patients (16 percent) were diagnosed with outlet obstruction, 12 (24 percent) with colonic inertia, and 31 (61 percent) with constipation of unclear etiology. Overall mean cost of diagnosis was $2,752 (range, $1,150-$4,792). Fiber, cathartics, or biofeedback therapy was successful in 33 of 51 (65 percent) patients. Among the remaining 18 patients, 12 underwent surgery, of which 10 were successful. The remaining eight patients were constipated, despite treatment. CONCLUSION: A cost of $140,369 was expended on extensive diagnostic tests, from which 12 of 51 (23 percent) patients benefited. Exhaustive diagnostic evaluation of constipation is costly, and its benefits are unclear.

Adult

Lower gastrointestinal bleeding.

BACKGROUND: Lower gastrointestinal bleeding can be a confusing clinical conundrum, the satisfactory evaluation and management of which requires a disciplined and orderly approach. Diagnosis and management has evolved with the development of new technology such as selective mesenteric angiography and colonoscopy. PURPOSE: This study was undertaken to review the available data in the literature and to determine the current optimum method of evaluation and management of lower gastrointestinal hemorrhage most likely to result in a successful outcome. METHODS: Data available on the topic of lower gastrointestinal bleeding in the English literature were obtained via MEDLINE search and were reviewed and analyzed. RESULTS: The colonic origin of lower gastrointestinal hemorrhage in order of decreasing incidence is diverticulosis, inflammatory bowel disease, including ischemic and infectious colitis, colonic neoplasia, benign anorectal disease, and arteriovenous malformations. Approximately 10 to 15 percent of all cases of rectal bleeding are attributable to a cause that is proximal to the ligament of Treitz. Small intestinal sources such as arteriovenous malformations, diverticula, and neoplasia account for between 3 and 5 percent of all cases. Colonoscopy successfully identified an origin in severe hematochezia in 74 to 82 percent of cases. Mesenteric angiography has a sensitivity of 42 to 86 percent. The best method of management depends on whether hemorrhage persists, the severity of continued hemorrhage, the cumulative transfusion requirement, and the specific origin of bleeding. CONCLUSION: Lower gastrointestinal hemorrhage is a complex clinical problem that requires disciplined and sophisticated evaluation for successful management. Diverticulosis is the most common cause. Colonoscopy is the diagnostic procedure of choice both for its accuracy in localization and its therapeutic capability. Selective mesenteric angiography should be reserved for those patients in whom colonoscopy is not practical. Precise identification of the bleeding source is crucial for a successful outcome. Specific directed therapy, such as segmental colonic resection for bleeding diverticulosis, is associated with the highest success rate and the lowest morbidity. A complete review of lower gastrointestinal bleeding is contained herein.

Angiography

Outcome of patients with total colonic ischemia.

PURPOSE: In this study, we sought to determine the outcome of patients with ischemic colitis, comparing patients with segmental disease with those with total colonic ischemia. METHODS: Patients with the diagnosis of ischemic colitis over the past six years were selected and reviewed for demographics, presenting symptoms, diagnosis, and treatment. RESULTS: Forty-three consecutive patients with ischemic colitis were identified and were grouped into those with segmental ischemic colitis and total colonic ischemia. Mean age was 68.8 years; 28 of 43 patients (65 percent) were males. Diagnosis was established by colonoscopy in 31 of 43 patients (72 percent), whereas in the remainder, diagnosis was made in the operating room. Ischemic colitis developed in the hospital in 17 of 43 patients (40 percent) during admission for an unrelated illness. In 6 of 43 (14 percent) of these patients, ischemic colitis developed following surgery. Thirty-one of 43 patients (72 percent) were found to have segmental colitis; 11 of 31 patients (35 percent) were successfully managed nonoperatively. Segmental colitis was present in 31 of 43 patients (72 percent), and 12 of 31 (35 percent) of these patients were successfully managed nonoperatively. In the patients with segmental colitis who required surgery, the 30-day mortality rate was 22 percent. Among 12 of 17 patients (71 percent) with segmental ischemia treated by resection and stoma, 9 of 12 (75 percent) underwent eventual stoma closure. All 12 patients with total colonic ischemia required surgery, and 9 of 12 patients (75 percent) died. CONCLUSION: Ischemic colitis occurs commonly during an unrelated hospital admission and following previous surgery. Most patients treated by resection and stoma undergo stoma closure. Total colonic ischemia carries a worse prognosis than segmental colonic ischemia.

Adult

Ischemic colitis complicating abdominal aortic aneurysm surgery in the U.S. veteran.

Ischemic colitis (IC) is an infrequent but serious complication of abdominal aortic surgery. Prior reports have generally described small, selected populations. The aim of this paper is to evaluate characteristics of clinically diagnosed IC in a large non-referral-based population. Using national Veterans Affairs (VA) computer data sets, we identified all patients with the diagnostic codes for both prosthetic replacement of aorta for abdominal aortic aneurysm and subsequent vascular insufficiency of the intestine in the entire VA population from 1987 to 1991. Clinical information on these patients was then requested from the VA Medical Centers where they received care. Patients demographics, clinical data regarding both the aortic surgery and IC, and survival data were extracted from patient charts and computer records. Of 4957 patients who underwent surgery of the abdominal aorta for infrarenal abdominal aortic aneurysm, 58 (1.2%) also had the code for subsequent IC. In 49/58 (74%), sufficient chart-derived and computer-derived data were available for analysis. The mean age was 69 (range 57-95); all were males. Bloody diarrhea was the most frequent symptom and colonoscopy the most common means of diagnosis. Mean time to diagnosis of IC was 5.5 days after aortic surgery (range 1-21 days). Aneurysmal rupture or perioperative hypotension were present in 35/49 patients. Bowel resection with fecal diversion was required in 32/49 (65%). The overall mortality was 54% but it was 89% if bowel resection for bowel infarction was required. Only 2/12 (16%) of those who required fecal diversion and survived underwent eventual stoma closure. Among 7 patients who received second-look laparotomy for IC, additional bowel resection was required in 6. No patient had aortic graft infection diagnosed during the index hospitalization. The overall mean hospitalization duration after the diagnosis of IC was 38 days (range 1-164). IC following aortic aneurysm surgery in this national patient population is infrequently diagnosed. Emergency aneurysm operation and perioperative hypotension are common in patients who develop IC. The majority of patients diagnosed receive surgical intervention. Most patients who undergo fecal diversion retain their stomas.

Aged

Ischemic colitis.

Ischemic colitis represents the most common form of gastrointestinal ischemia. The presumed etiologies are numerous; however, it typically develops "spontaneously," in the absence of major vasculature occlusion, and in the presence of viable intestine elsewhere. It is most usefully classified into gangrenous and nongangrenous forms, the latter of which may be subdivided into transient and chronic types. Ischemic colitis may develop in people who are otherwise healthy, although a variety of clinical settings, such as shock, predispose to its occurrence. It usually presents as an acute abdominal illness with bloody diarrhea. Diagnosis is confirmed by colonoscopy. Therapy and outcome are dependent on the severity of disease. Nongangrenous colonic ischemia usually requires only medical management and is associated with a good prognosis. The chronic subtype may lead to the sequelae of persistent segmental colitis or colonic strictures, occasionally requiring surgery. Urgent operative intervention and a high morbidity and mortality are the hallmarks of gangrenous colonic ischemia. Special considerations must be given to those patients in whom ischemic colitis develops in the context of colon carcinoma or obstructing colon lesions, after abdominal aortic surgery, and following cardiopulmonary bypass. This review will discuss the clinical spectrum of ischemic colitis.

Colitis, Ischemic

Internal pudendal flap anoplasty for severe anal stenosis. Report of a case.

PURPOSE: A technique for introducing anoderm into the anal canal is described. METHODS: An internal pudendal flap was used. RESULTS: This technique was totally successful in alleviating anal stenosis and maintaining fecal continence. CONCLUSION: Internal pudendal flap should be in the armamentarium of the colon and rectal surgeon for treating severe anal stenosis.

Aged

Colorectal cancer in patients with previous spinal cord injury.

BACKGROUND: The optimum management of large-bowel cancer in patients with previous spinal cord injury (SCI) is uncertain. PURPOSE: The aim is to determine the outcome of patients with SCI who are undergoing colectomy or proctectomy for cancer. METHODS: A population-based study of patients receiving care at hospitals in the Department of Veterans Affairs system from 1987 to 1991 was performed. Patients with ICD-9 codes for SCI and colon and rectal cancer were identified. Patients with previous SCI who underwent colectomy or proctectomy for their cancer comprised the study population. Data were compiled from national computerized Veterans Affairs datasets, supplemented by individual operative reports and discharge summaries. RESULTS: Forty-four patients were evaluable. Mean age was 65 (range, 40-80) years, and mean time since SCI was 24 (range, 1-50) years. Mean follow-up was 4.6 years after resection. Distribution of tumors was 39 percent rightsided, 43 percent left-sided, and 18 percent rectal. All 32 patients with colonic tumors underwent resection; 26 of 32 patients (81 percent) had an anastomosis. Seven of eight (88 percent) rectal lesions were treated by abdominoperineal resection. Twenty-six of 44 patients (59 percent) presented with Stage III or IV disease. Twelve of 44 (27 percent) died, 8 of 12 from cancer. Overall 30-day mortality rate was 4.5 percent (2/44). In-hospital morbidity rate (pulmonary, cutaneous, and urinary tract only) was 34 percent. Among those who received postoperative chemotherapy, 80 percent completed treatment. CONCLUSIONS: Patients with previous SCI tolerate resection well. Tumor distribution and stage are similar to those of neurally intact patients. Morbidity is commonly related to pre-existing complications of SCI. Adjuvant therapy is well tolerated.

Adult

Colonoscopic perforations. Etiology, diagnosis, and management.

Since its introduction into clinical medicine, flexible fiberoptic colonoscopy has had a great impact on diagnosis and management of diseases of the colon and rectum. There are three mechanisms responsible for colonoscopic perforation: specifically, mechanical perforation directly from the colonoscope or a biopsy forceps, barotrauma from overzealous air insufflation, and, finally, perforations that occur during therapeutic procedures. Perforation of the colon, which requires surgical intervention more frequently than bleeding, occurs in less than 1 percent of patients undergoing diagnostic colonoscopy and may be seen in up to 3 percent of patients undergoing therapeutic procedures such as polyp removal, dilation of strictures, or laser ablative procedures. Management of colonic perforation secondary to colonoscopy remains a controversial issue in that it can be effectively managed by operative and nonoperative measures. If a perforation does occur, signs and symptoms that the patient will experience will be related to both the size and site of the perforation, adequacy of the bowel preparation, amount of peritoneal soilage, underlying colonic pathology (where a thin walled colon from colitis or ischemia, for example, may result in a larger perforation than a healthy colon), and, finally, overall clinical condition of the patient. Radiology often establishes diagnosis. Plain films of the abdomen and an upright chest x-ray may reveal extravasated air confined to the bowel wall, free intraperitoneal air, retroperitoneal air, subcutaneous emphysema, or even a pneumothorax. A localized perforation may demonstrate lack of pneumoperitoneum. Some surgeons recommend surgery for all colonoscopic perforations; however, there does appear to be a role for conservative management in a select group of patients such as those with silent asymptomatic perforations and those with localized peritonitis without signs of sepsis that continue to improve clinically with conservative management. Finally, conservative management works well in those patients with postpolypectomy coagulation syndrome. Surgery is most definitely indicated in the presence of a large perforation demonstrated either colonoscopically or radiographically and in the setting of generalized peritonitis or ongoing sepsis. The presence of concomitant pathology at time of colonoscopic perforation such as a large sessile polyp likely to be a carcinoma, unremitting colitis, or perforation proximal to a nearly obstructing distal colonic lesion may force immediate surgery. Finally, in the patient who deteriorates with conservative management, one should proceed to surgery.

Algorithms

Collagenous colitis: pathogenesis and management.

INTRODUCTION: Collagenous colitis is a rare disease of unknown etiology that primarily affects middle-aged women. It presents with chronic watery diarrhea and thickening of the subepithelial collagen layer of the colonic mucosa in the absence of endoscopic abnormalities. PURPOSE: This study was undertaken to review the current literature on clinical course, pathology, diagnosis, and current management of collagenous colitis. RESULTS: Collagenous colitis is an inflammatory disease of the colon, clinically characterized by a waxing and waning course of watery diarrhea, an inflammatory infiltration of the colonic mucosa, and a thickening of the subepithelial collagen layer. Its pathogenesis remains unclear, but there is evidence for an inflammatory process triggered possibly by an uncommon luminal agent. Diagnosis is established by colonic biopsies; in the setting of normal colonic mucosa, the disorder is primarily managed medically with virtually no role for surgery. CONCLUSIONS: Pathogenesis of collagenous colitis remains unclear. Current data favor an inflammatory etiology, possibly involving an initiating luminal insult. Guidelines for diagnosis are being established, and medical treatment options are variably effective in the majority of cases. Very unusual refractory cases may benefit from surgical management.

Biopsy

Diverticular hemorrhage in the elderly--is it well tolerated?

PURPOSE: Elderly patients frequently develop lower gastro-intestinal bleeding secondary to diverticulosis. This select group of patients potentially tolerates blood loss poorly, often have coexisting cardiovascular morbidity, and may not tolerate surgical intervention. Thus, optimal management of elderly patients with diverticular hemorrhage remains difficult. METHODS: All patients who were admitted with the diagnosis of diverticulosis at the St. Louis University affiliated hospitals during the past 60 months were identified. Those with diverticular bleeding were extracted. Patients were reviewed as to age, sex, diagnosis of diverticular bleeding, number of bleeding episodes, lowest hemoglobin before transfusion, amount of blood received, treatment, operations, the presence of recurrent bleeding, morbidity, and mortality. RESULTS: One hundred fifteen consecutive patients, age 70 years admitted with lower gastrointestinal hemorrhage secondary to diverticulosis who required transfusion, were identified. Mean age was 79 years; 26 of 115 (23 percent) were more than 80 years of age; 78 of 115 (54 percent) were males; 39 of 115 (34 percent) had more than one previous admission for diverticular hemorrhage. The mean serum hemoglobin was 8.9 g/dl. All patients underwent colonoscopy; 34 of 115 (29 percent) underwent 99Tc scanning, of which 18 of 34 (54 percent) underwent arteriogram. Seven of 18 (39 percent) demonstrated extravasation secondary to bleeding diverticulosis. The mean transfusion requirement was 2.8 (range, 1-17) units; 21 of 115 (18 percent) required intestinal resection; 2 of 21 (9 percent) experienced a 30-day mortality. Among those, 94 of 115 were treated without surgery, and 3 of 94 (4 percent) died. Mortality was independent of initial hemoglobin (P = 0.21), previous diverticular hemorrhage (P = 0.44), amount of blood transfused (P = 0.36), and type of treatment (0.09). CONCLUSIONS: Most diverticular bleeding in the elderly is well tolerated using nonoperative management. Success and safety of treatment does not seem to depend on a history of previous diverticular bleeding, initial hemoglobin, or amount of blood transfused. The majority of patients are treated nonoperatively. Surgical intervention seems to be well tolerated.

Aged

Role of cytokines and platelet-activating factor in inflammatory bowel disease. Implications for therapy.

BACKGROUND: Platelet-activating factor (PAF) and cytokines, such as interleukins, tumor necrosis factor, and others, are thought to play a role in the inflammatory process involving gastrointestinal disorders such as Crohn's disease, ulcerative colitis, ischemic colitis, or antibiotic-associated colitis. PURPOSE: This study was undertaken to review the latest literature on the role of PAF and cytokines in the genesis of inflammatory bowel disease and implications for therapy and management. RESULTS: PAF is an endogenous phospholipid involved in hypersensitivity and inflammatory reactions such as platelet and neutrophil aggregation, vasodilation, increased vascular permeability, and leukocyte adhesion, which have been associated with inflammatory processes. Cytokines are peptides that regulate and coordinate inflammatory and immunologic responses. Increased production of cytokines has been reported during Crohn's disease and ulcerative colitis and is correlated with disease activity. CONCLUSIONS: Because PAF and cytokines may have an important role in the pathogenesis of inflammatory bowel disease, their inhibition by specific antagonists, mediators, or other agents such as steroids may have a potential therapeutic benefit in treatment and management of these inflammatory diseases in the near future.

Animals

How practice patterns in colon cancer patient follow-up are affected by surgeon age.

BACKGROUND: Strategies for the follow-up of colon cancer patients after potentially curative treatment are known to vary widely. The optimal regimen remains unknown. We investigated whether the date of completion of formal surgical training affects choice of surveillance strategy. METHODS: The 1070 members of the Society of Surgical Oncology (SSO) and the 1663 members of the American Society of Colon and Rectal Surgeons (ASCRS) were surveyed using a detailed questionnaire to measure how these surgical experts deal with colon cancer follow-up. Subjects were asked how they use nine specific follow-up modalities during years 1-5 following primary treatment for patients with colon cancer (TNM Stages I-III). Repeated-measures analysis of variance was used to compare practice patterns by TNM stage and year post-surgery, as well as by the year in which the surgeon's formal surgery training was completed. RESULTS: Evaluable responses were received from 349 SSO members (33%) and 646 ASCRS members (39%). Few significant differences in follow-up practices were noted by training period, but follow-up for most of the nine modalities was highly correlated with TNM stage and year post-surgery, as expected. CONCLUSIONS: This analysis indicates that the post-treatment surveillance practice patterns of surgeons caring for patients with colon cancer do not vary substantially with practitioner age. The data provide credible evidence that postgraduate education is effective in homogenizing practitioner behaviour.

Age Factors

Geographic variation in patient surveillance after colon cancer surgery.

PURPOSE: Considerable variation among surgeons exists in the current practice of patient surveillance after colon cancer treatment. We evaluated whether geographic factors are responsible for this observed variation. METHODS: Profiles of hypothetical patients and a detailed questionnaire based on the profiles were mailed to 2,733 members of two national surgical societies. The influence of the geographic location of the respondents on practice patterns were assessed in two ways. Repeated-measures analysis of variance was used to compare the practice patterns among 19 large metropolitan statistical areas (MSAs) and chi 2 analysis was used to determine whether these patterns differed by MSA population size. RESULTS: Seven of nine commonly used surveillance modalities were ordered significantly more frequently with increasing tumor-node-metastasis (TNM) stage and significantly less frequently with year postsurgery among the 995 respondents with assessable responses, but MSA population size and geographic location of physicians generally had no effect on documented practice variability. The remaining two modalities (bone scan and computed tomography [CT]) were used so infrequently as to preclude meaningful analysis. CONCLUSION: Surveillance after potentially curative colon cancer surgery for otherwise healthy patients is not significantly affected by the geographic location of the surgeon who performs the surveillance testing and only modestly affected by the population size of the MSA in which he/she practices. These data should help in the design of prospective trials of this topic.

Analysis of Variance

Complications of endoscopic polypectomy.

Colonoscopic polypectomy has revolutionized the treatment of benign colonic neoplasia. It is performed widely by gastroenterologists and surgeons and is a safe procedure. The two major complications of colonoscopic polypectomy include hemorrhage which has a reported incidence of 0.2% to 3% and perforation which has a reported incidence of 0.5% to 3%. Factors that increase the risk of these complications and management strategies are discussed in this review.

Colonoscopy