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Toxic megacolon. An analysis of 70 cases.

The clinical features and outcome of 70 patients treated for toxic megacolon between 1970 and 1984 in five university-affiliated hospitals were determined. There were 35 women and 35 men with a mean age of 39 +/- 0.2 years. Toxic megacolon occurred at the initial episode of colitis in 43 patients (61 percent). Only five patients had a specific colitis: salmonellosis, two; ischemic, two; and pseudomembranous, one. Of the 65 remaining patients with nonspecific colitis, six had to be operated on without delay because of peritonitis. In the remaining 59 patients, toxic megacolon was cured with intensive medical management in nine (15 percent), improved temporarily in 14 (24 percent), and remained unchanged in 36 (61 percent). The postoperative mortality rate was 11 percent for all patients (6/56), 4 percent for patients without perforation (2/50) compared with 27 percent for patients with perforation (4/15). None of the patients who underwent surgery within five days of medical treatment died. When toxic megacolon was complicated by hemorrhage (nine patients) or peritonitis (eight patients), the mortality rate increased to 33 percent and 27 percent, respectively. A one-stage proctocolectomy was performed in 19 patients (32 percent). Of 32 patients in whom the rectum was retained, successful restoration of continuity was possible in only seven (22 percent) within 12 months after surgery. In well-selected patients, a plea is made for rectal preservation to offer an alternative to permanent ileostomy.

Adolescent↗

Total proctocolectomy and ileal J-pouch anal anastomosis for chagasic megacolon with fecaloma: report of a case.

Megacolon, resulting in severe constipation, is one of the most common manifestations of Chagas' disease. We herein report a case of megacolon with fecaloma in a 39-year-old Brazilian man who presented with severe constipation. He underwent a total proctocolectomy and ileal J-pouch anal anastomosis. Histologically, there was a marked thickening of the proper muscle layer, and a moderate decrease in the myoenteric nerve plexuses and neurons in the megacolon area. A feasible outcome has been achieved after a 1-year follow-up. A total proctocolectomy with ileal J-pouch anal anastomosis may therefore be one of the useful strategies for the surgical treatment of patients with chagasic megacolon.

Anal Canal↗

Toxic megacolon: ultimate fate of patients after successful medical management.

The clinical course and ultimate outcome in 38 patients with toxic megacolon who were successfully treated nonoperatively has been reviewed. Thirty-two patients had ulcerative colitis and 6 had Crohn's disease. Follow-up was complete and ranged from 3 to 22 years (average 13 years). Eleven of 38 patients (29 percent) eventually suffered second episode of fulminant acute colitis or recurrent toxic megacolon. Ultimately, a total of 18 patients (47 percent) underwent colon resection, which was performed on an emergency or urgent basis in 15 patients. A modified Visick classification was employed to assess the long-term results of medical therapy in the entire group, in patients showing improvement within 48 or 72 hours, in patients 30 years or younger, in patients whose initial presentation of inflammatory bowel disease was toxic megacolon, and in patients with ulcerative colitis as opposed to Crohn's disease. The results were equally poor for all subgroups, and they have strengthened our opinion that medical management of toxic megacolon should be regarded almost exclusively as preparation for imminent surgery.

Adolescent↗

Induction of nitric oxide synthase in colonic smooth muscle from patients with toxic megacolon.

BACKGROUND & AIMS: Colonic inflammation may lead to motility disturbances, including severe atony. Nitric oxide is released by inflamed tissue and induces smooth muscle relaxation. The aim of this study was to analyze NO generation pathways in colonic tissue from patients who had ulcerative colitis with or without toxic megacolon and in tumor-free samples from patients with colonic neoplasm. METHODS: Enzymatic activity was determined by transformation of [14C]arginine to [14C]citrulline in mucosa and muscular layer samples. Immunostaining of tissue sections with antibody against inducible NO synthase was investigated. The effects of endotoxin on NO synthase activity was tested in muscle strips from human colon. RESULTS: Ca(2+)-independent NO synthase was undetectable or very low in muscularis propria from tumor and colitis controls. In contrast, specimens from patients with toxic megacolon had high activity (P < 0.05). Positive immunostaining for inducible NO synthase was found in muscular layers from patients with megacolon but not in tumor and colitis controls. Finally, endotoxin induced Ca(2+)-independent NO synthase activity in colonic muscle. CONCLUSIONS: Toxic megacolon is associated with the appearance of inducible NO synthase in the colonic muscularis propria. Local generation of excessive amounts of NO may be responsible for the colonic dilatation that is the hallmark of this syndrome.

Adult↗

Acquired megacolon is associated with alteration of vasoactive intestinal peptide levels and acetylcholinesterase activity.

Based upon previous morphologic studies, we hypothesized that the development of acquired megacolon was associated with abnormalities of enteric neurotransmitter concentrations and enzymatic activities. Specimens were obtained at surgery from patients with normal descending-sigmoid colon (n = 13) and patients with sigmoid megacolon (n = 6; defined by radiologic measurement). Radioimmunoassays were used to measure the non-adrenergic, non-cholinergic inhibitory neuropeptide, vasoactive intestinal peptide, and the non-adrenergic, non-cholinergic excitatory neuropeptide, substance P, while spectrophotometric assays were used to quantitate acetylcholinesterase activity and choline acetyltransferase activity. There were significantly decreased concentrations of vasoactive intestinal peptide and decreased acetylcholinesterase activity in muscularis externa from patients with acquired megacolon. In megacolon, vasoactive intestinal peptide-containing nerve fibers appeared to be diminished in circular and longitudinal smooth muscle, and immunostaining of nerve cell bodies in the plexus submucosus externus appeared diminished. These results suggest the hypothesis that production of vasoactive intestinal peptide is altered allowing secondary colonic hypertrophy to develop from prolonged cholinergic nerve-mediated contractions of circular smooth muscle. As a corollary to this hypothesis, colonic dilatation might result from prolonged contraction of longitudinal smooth muscle.

Acetylcholinesterase↗

Megacolon in cats. The role of colectomy.

In cats, clinical signs of constipation usually respond to laxatives, fecal softeners, enemas, and dietary management. Uncommonly, constipation is chronic and is associated with a marked increase in the diameter of the colon. When megacolon is present, constipation responds poorly to medical therapy. Without surgical treatment, megacolon may become an intolerable problem, with euthanasia of the cat as the probable outcome. Subtotal colectomy is now established as a satisfactory treatment for idiopathic megacolon in cats. Recently, removal of the colon has been used successfully to treat chronic constipation and megacolon associated with mechanical obstruction of the pelvic canal caused by stenosis from malunion of pelvic fractures. Colectomy has minimal long-term effects on enteric function in cats.

Animals↗

[Toxic megacolon--the position of the internist].

Toxic megacolon is a rare but typical complication of ulcerative colitis. But also every inflammatory bowel disease may be cause of toxic megacolon, including especially Crohn's colitis and pseudomembranous colitis (PMC). There is to mention, that PMC becomes more frequent and more important in the last years. Toxic megacolon is defined by radiological, clinical and labaratory criteria: colonic distension (<6 cm), fever, tachycardia, hypotension, electrolyte disturbances, leucocytosis and anemia. Intensive medical therapy is primarly the therapy of choice, but clinical parameters should be closely monitored. In patients with ulcerative colitis high dosis of corticosteroids are given intravenously. If there is no clinical improvement after 48 to 72 hours, colectomy is required. The use of alternative therapies like cyclosporine or infliximab has to be discussed as possible before toxic megacolon occurs.

Adrenal Cortex Hormones↗

[Toxic megacolon--surgical point of view].

Toxic megacolon is an infrequent, but potentially fatal complication of a fulminant colitis. Toxic colonic dilatation, also caused by ischaemic or infectious inflammation like pseudomembranous colitis, mostly occur in patients with inflammatory bowel disease. Toxic mega-colon is defined as segmental or total colonic distension of >6 cm with the presence of clinical signs of acute colitis and systemic toxicity. Because of the associated high morbidity and mortality the early diagnosis and the management play an important role. The free perforation means a fourfold increase in the mortalitiy of the acute colitis. Recognition of toxic megacolon is underlaying by x-ray of the abdomen with colonic distension and a lack of haustral pattern. Accompanying distension of the small bowel can predict the development of the disease. CT scanning shows a diffuse wall thickening, pericolic inflammation and abnormal haustral pattern and can also detect subclinical perforation or abscesses. The management of toxic megacolon should be with intravenous parenteral nutrition, adaequate supplementation of intravenous fluids and correction of electrolytes abnormalities and the therapy of colitis with corticosteroids. Antibiotics are indicated in infectious disease or bacteriemia and also in colonic perforation. Surgical intervention is indicated by the onset of signs of progression of the disease and complications as perforation, uncontrollable bleeding or distension. The surgical procedure of choice is colectomy and ileostomy. The mortality and morbidity was decreased by avoiding rectal excision. The rectum is closed as a Hartmann's procedure or a mucous fistula is created. A secondary ileoanal pouch can be created at a later date. The interdisciplinary approach with optimal timing of surgical intervention can decrease the morbidity and mortality of toxic megacolon.

Colectomy↗

The relationship between megacolon and carcinoma of the colon: an experimental approach.

'Carcinoma of the colon does not occur in cases of megacolon' is an axiom held by Brazilian physicians working in endemic areas for Chagas' disease. The objective of the present study was to test this axiom experimentally by submitting rats with experimental megacolon to a carcinogen which causes carcinoma of the colon. Eighty young male Wistar rats received serosal application of either saline (0.9% NaCl) or 2 mM benzalkonium chloride (BAC) to the distal colon. Ten months later randomly chosen saline and BAC rats were injected weekly with dimethylhydrazine (DMH) for 20 weeks. Non-DMH-treated rats from both original groups were maintained, for a total of four experimental groups. Three months after the injections all surviving rats were killed. At autopsy the presence of absence of carcinomas along the colon was recorded. The induction of megacolon was evaluated by morphometry of the wall from the distal colon and myenteric denervation was assessed by neuron counts. An increase of at least 2-fold in distal colon wall thickness confirmed the induction of megacolon in BAC-treated rats. Neuronal counts from BAC and control rats not treated with DMH showed an average denervation of 63%. The number of distal colon carcinomas in BAC+DMH-treated rats was significantly lower than that in DMH-treated rats. These findings appear to contradict the traditional concept of carcinogenesis of the colon. The clinical axiom was reproduced experimentally.

1,2-Dimethylhydrazine↗

Toxic megacolon complicating Crohn's colitis.

Toxic megacolon complicating ulcerative colitis has been a well-recognized entity since its original description in 1950. The presence of toxic megacolon frequently has precluded a diagnosis of Crohn's colitis. Recent literature, however, has demonstrated that the incidence of toxic megacolon associated with Crohn's colitis (4.4-6.3%) may be higher than that in ulcerative colitis (1-2.5%). Differentiation between these two catastrophic forms of colitis is important in respect to prognosis and long-term results. Medical management of toxic megacolon may be initially successful in either type of colitis. Surgical intervention is indicated if the patient's condition does not improve within 48-72 hours. A subtotal colectomy with an ileostomy and mucous fistula is probably the treatment of choice for most of these extremely ill patients. The influence of the type of colitis on the results of subsequent management of the rectal stump remains unresolved.

Adult↗

Factors associated with intestinal perforation in children's non-typhi Salmonella toxic megacolon.

BACKGROUND: To evaluate the risk factors for intestinal perforation in children with toxic megacolon caused by non-typhi Salmonella infection. METHODS: During an 11-year period we reviewed the records of children treated for non-typhi Salmonella infection. All of the subjects had positive stool culture for non-typhi Salmonella and were treated with intravenous ceftriaxone during hospitalization. Clinical data reviewed included demographic features, clinical manifestations, laboratory findings, radiologic findings, microbiology, therapeutic effect of hydration and rectal tube placement and the operative findings. Patients with toxic megacolon were defined as those having toxic appearance, diarrhea, high fever (>39 degrees C) and marked colon dilatation with maximal diameter > 1.5 times the width of the vertebra body of the first lumbar spine (L1-VB). To define the risk factors for patients with toxic megacolon complicated by intestinal perforation, patients were divided into two groups for analysis: P group, those complicated with intestinal perforation; and NP group, those without intestinal perforation. Differences in age, sex, severity of diarrhea, duration of fever, hemogram and its differential, culture, stool analysis, serum C-reactive protein (CRP), electrolytes, maximal colon diameter, medical therapy and timing of rectal tube insertion between the two groups were analyzed. Statistical analyses were conducted with chi square tests and multiple logistic regression. RESULTS: A total of 75 patients (P group, 27 patients; NP group, 48 patients) ages 4 months to 6 years were evaluated. With chi square analysis 7 variables were found to be significantly associated with intestinal perforation: age >1 year; fever >5 days; ratio of immature to total neutrophils >20%; serum CRP >200 mg/l; colon diameter >2.5 times the width of L1-VB; inadequate early hydration; and delay in rectal tube insertion. With multivariate analysis age >1 year, serum CRP >200 mg/l and colon diameter >2.5 times of width of L1-VB, inadequate early hydration and delay in rectal tube insertion were the most significant factors associated with intestinal perforation. CONCLUSION: Identification of patients with toxic megacolon associated with non-typhi Salmonella infection at risk for further intestinal perforation is possible. Early effective fluid resuscitation and rectal tube insertion may be helpful to prevent the occurrence of intestinal perforation.

Child↗

Comparison of biofragmentable anastomosis ring and sutured anastomoses for subtotal colectomy in cats with idiopathic megacolon.

OBJECTIVE: To report use of a biofragmentable anastomosis ring (BAR) device in cats with idiopathic megacolon (FIM) and compare outcome after subtotal colectomy with sutured colocolic anastomosis. STUDY DESIGN: Retrospective study. ANIMALS: Nineteen cats with megacolon. METHODS: Medical records (January 1990-January 2004) of cats treated surgically for idiopathic megacolon with sutured (SUT) or BAR anastomosis were retrieved and reviewed. Operative, short- and long-term complications, and survival times were recorded and Kaplan-Meier survival analysis used to assess outcome. RESULTS: There were 11 SUT and 8 BAR cats. One BAR cat had anastomotic dehiscence 36 hours after surgery. Mild serosal tearing during BAR insertion in 6 cats was corrected by suture reinforcement. One SUT cat developed anastomotic stricture at 32 days. Short-term complication rates at 3 and 7 days were 18% and 45% in the SUT group and 25% and 87.5% in the BAR group, respectively (P=.058). Two SUT cats had persistent loose stool consistency and were euthanatized 254 and 1661 days after surgery. One BAR cat had recurrence of constipation which was managed medically. Long-term complication rates were not significantly different between SUT and BAR (P=.61). The 1 and 4-year survival rates were 90% for SUT and 100% for BAR (P=.29). CONCLUSIONS: No difference was detected for short and long-term complication rates and survival times between SUT and BAR groups. CLINICAL RELEVANCE: The BAR device can be used for colocolic anastomosis in cats with idiopathic megacolon. Serosal tearing during BAR insertion was a common intraoperative complication. Regardless of anastomotic technique, survival outcome after colonic resection is excellent for cats with FIM.

Anastomosis, Surgical↗

Hirschsprung's disease and idiopathic megacolon in adults and adolescents.

The distinction between Hirschsprung's disease and idiopathic megacolon in childhood dates from the classic clinical, radiological, and histological studies of Bodian, Stephens, and Ward. This article describes clinical experience over 15 years of 94 patients in whom megacolon of these two types was recognised for the first time after the age of 10, to illustrate the problems of diagnosis and treatment in later years. Just as it is now recognised that patients with the clinical characteristics of Hirschsprung's disease may have one of several abnormalities of the myenteric plexus, including not only absence of ganglion cells, but also patchy or zonal loss, abnormal neurones or neuronal dysplasia, so idiopathic megacolon may also be a heterogeneous group of cases. This paper suggests on clinical grounds that those patients with idiopathic megacolon whose symptoms start in childhood differ from those whose symptoms develop in later years.

Adolescent↗

Oesophageal manometry in the evaluation of megacolon with onset in adult life.

BACKGROUND: Oesophageal motility is often impaired in patients with megaduodenum and other forms of intestinal pseudo-obstruction in which a visceral myopathy or neuropathy may be present. Idiopathic longstanding megacolon with onset in adult life is still a poorly defined entity, which may also be part of a more widespread motility disorder but in which oesophageal motility has not been yet systematically studied. AIMS: To assess oesophageal motility in patients with longstanding idiopathic megacolon with onset in adult life. PATIENTS: 14 consecutive subjects with idiopathic megacolon whose symptoms began after the age of 10 and a clinical history of 2-22 years. METHODS: Standard barium enema, water perfused oesophageal manometry, and also anorectal manometry. RESULTS: Oesophageal motility was impaired in five patients (36%; 95% confidence intervals 16 to 61%). Normal peristalsis was substituted by low amplitude multiple peaked simultaneous contractions in four subjects and by undetectable contractions in one. In three of them the lower oesophageal sphincter did not relax after swallows; in the same patients anal relaxation after rectal distension was also undetectable. All five patients with impaired oesophageal motility had a colonic dilatation sparing the rectum. Three of them reported constipation and a history of pesudo-obstruction and the other two only abdominal distension. CONCLUSIONS: Oesophageal manometry should be performed in patients with longstanding idiopathic megacolon with onset in adult life, in particular if the rectum is not dilated and even in absence of pseudo-obstruction. This simple test may disclose a more widespread visceral neuropathy or myopathy. Such a diagnosis helps to better understand the cause of the colonic dilatation and may be clinically relevant for treatment of the patients.

Adolescent↗

[Fatal toxic megacolon due to cytomegalovirosis in a patient with ulcerative colitis: case report and review].

BACKGROUND: The toxic megacolon is a rare and severe complication of ulcerative colitis. In general it complicates patients with active colitis that are resistant to clinical treatment and, in some cases, the developing factor is unknown. Cytomegalovirus infection in humans in general is a subclinical condition. However, in patients with immunodeficiency the primary infection or the reactivation of latent infection could have enormous clinical effects. One of these effects is the toxic megacolon. AIM: To report a case of fatal toxic megac lon due to cytomegalovirosis in a patient with ulcerative colitis. PATIENT: A male patient, 38 years old, with complaints of diarrhea and weight loss. The diagnosis of ulcerative colitis was made and a vigorous immunossupressive therapy was performed. RESULTS: Due to the evolution to a toxic megacolon the patient was submitted to colectomy. In the post-operatory period there were severe clinical complications and the patient died. The pathological study of the colon revealed active ulcerative colitis, associated with confluent ulcerations and numerous cells with cytomegalic nuclear inclusions. CONCLUSION: The cytomegalovirosis must be considered as one of the causal agent of toxic megacolon in ulcerative colitis.

Adult↗

A patient who survived total colonic ulcerative colitis surinfected by cytomegalovirus complicated by toxic megacolon and disseminated intravascular coagulation.

The authors report the case of a patient aged 60-year-old who survived ulcerative colitis complicated by toxic megacolon and disseminated intravascular coagulation. This patient was not known for this ulcerative colitis and was first hospitalised for a suspicion of diverticulitis. The admission symptoms were fever, abdominal pain and bloody diarrhoea. The evolution was defavorable under antibiotics and sulfasalazine. The patient was readmitted 5 days after he left hospital, and the diagnosis of UC was based on colon biopsy made during the first hospitalisation. A treatment with methylprednisolone was started and the patient worsened day by day with apparition of toxic megacolon and disseminated intravascular coagulation. Subtotal colectomy was performed for degradation of general status and coagulation factors. Pathological findings confirmed ulcerative colitis with toxic megacolon. Cytomegalovirus inclusions were demonstrated on the colonic specimen and confirmed by PCR. In this report the authors discuss the etiology of toxic megacolon and disseminated intravascular coagulation in ulcerative colitis surinfected by cytomegalovirus. Mortality of these pathologies is high necessitating rapid diagnosis of cytomegalovirus infection by sigmoid biopsy. Management requires immunosupression interruption and ganciclovir therapy, or surgery in unsuccessful medical treatment.

Biopsy, Needle↗

[Incidence of diverticular disease of the large bowel in non-chagasic and chagasic individuals with and without megacolon].

To study the frequency of association between two common colonic disease in our midst, chagasic megacolon and diverticular disease, we reviewed the barium enemas of 243 patients aged more than 35 years. Diverticula were detected in 22 (21.6%) of the 102 non-chagasic individuals, in 10 (35.7%) of 20 chagasics without megacolon, and in 14 (12.4%) of the 113 chagasics with megacolon. There was a statistically significant difference between the two chagasic groups, but not between each one of them and the non-chagasic group. The incidence of diverticula in the sigmoid colon of the non-chagasic group was significantly higher than in the sigmoid colon of the other two groups studied. Among the patients with association of megacolon and diverticular disease, the diverticula were always located in the nondilated portions of the large bowel. It is suggested that totally unfavorable conditions for the genesis and/or maintenance of diverticula exist in the dilated colon of chagasic patients.

Adult↗

Endoscopic colonic decompression of toxic megacolon, placement of colonic tube, and steroid colonclysis.

A case of inflammatory bowel disease with toxic megacolon decompressed by colonoscopy, placement of an indwelling colonic tube through which steroid solution was administered. Toxic megacolon was alleviated, thus suspending the impending surgery. Literature search did not reveal any similar approaches of treating toxic megacolon. This procedure, however, should not replace the proper surgical management of toxic megacolon of inflammatory bowel disease.

Colitis, Ulcerative↗