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Endoscopic decompression of the bowel in "toxic megacolon" is presented in two cases as an alternative procedure to Turnbull's technique using multiple bowel fistulas. In our opinion this technique seems to be a substantial improvement in the treatment of "toxic megacolon" and may even help to prevent ileotomy-colotomy in some cases.
Twenty-five patients with toxic megacolon are reported. The most frequent etiology of this syndrome was ulcerative colitis and the main complication colonic perforation. Toxic dilatation generally involved the transverse colon. Twenty patients were treated by a surgical procedure, namely two enterostomies and eighteen colectomies. A total colectomy with ileorectal anastomosis was performed in ten patients. Mortality for the whole series was 32%, but was reduced to 14% in the last 4 years. There were no deaths and no complications needing surgical management in the group of patients treated by total colectomy with ileorectal anastomosis. However, the method resulted in one failure. The satisfactory results obtained with this procedure must be emphasized. Despite the small number of so-treated patients reported in world literature, it is suggested that total colectomy with ileorectal anastomosis must be regarded as the procedure of choice for toxic megacolon without peritonitis.
The motility of the sigmoid colon and rectum was studied by manometry in patients with Chagasic megacolon and in control individuals using two different experimental procedures: (1) intravenous infusion of saline, followed by intravenous infusion of cholecystokinin octapeptide (OP-CCK) at the dose of 20 ng/kg/hr; and (2) intraduodenal instillation of saline followed by a solution of essential amino acids at a flow of 10 ml/min. CCK-OP induced an increase in motility index in the sigmoid colon (P less than 0.05) and rectum (P less than 0.05) in the controls, whereas intraduodenal infusion of amino acids produced a significant increase in motility index exclusively in the sigmoid colon (P less than 0.005). A significant increase (P less than 0.05) in sigmoid colon motility also occurred in the control group after duodenal saline infusion was interrupted. The release of other substances in addition to CCK must have been responsible for the different behavior of sigmoid colon and rectum in response to the stimuli used. Neither procedure caused significant changes in the motility of the sigmoid colon or the rectum of the Chagasic patients. The extensive intramural denervation occurring in Chagasic megacolon probably destroys the neural pathway through which OP-CCK and the substances released by the duodenum by the infusion of essential amino acids activate the motor cells of the human terminal intestine.
Adult patients with an idiopathic megarectum or megacolon can experience severe constipation requiring surgical treatment. Some of these patients have a proximal colon of normal diameter, with dilatation involving only the left or distal colon and rectum. The results of partial colonic and rectal resection with coloanal anastomosis in such patients have been reviewed. Seven patients (two female and five male) underwent a coloanal anastomosis over a seven-year period. The median age at operation was 19 years, the mean age at onset of symptoms was five years, and the mean follow-up period was one year. Five patients experienced a return to normal bowel frequency with the loss of most symptoms. One patient has an ileostomy because of persistent constipation after the procedure. One subject died because of postoperative bleeding from the anastomosis and subsequent cardiac and respiratory complications. This operation may have a place in the treatment of severe constipation caused by idiopathic megarectum and megacolon, but careful preoperative motility studies and meticulous attention to operative technique are required for a good outcome.
An immunoperoxidase staining method was used to study specific immunoglobulin-containing cells in the intestinal mucosa of children who presented with features suggestive of Hirschsprung's disease. No evidence was found to substantiate the hypothesis of an immunologic component in the etiology of Hirschsprung's disease. The megacolon in this condition had an increased proportion of IgG-containing cells and a reduced proportion of IgA-containing cells when compared with normal and unobstructed colon; this may be a reflection of an abnormal mucosal immune defense leading to susceptibility to the enterocolitis found in Hirschsprung's disease. Numerous lipofuscin-bearing macrophages were seen in the colonic mucosa of children with anal stenosis who were given anthraquinone laxatives for varying periods. The possibility that this represents an early stage of melanosis coli, as well as the likelihood of anthraquinones contributing to the pathogenesis of acquired megacolon, are considered.
Toxic megacolon has rarely been reported in the course of antibiotic-induced pseudomembranous colitis. We have been able to collect 20 cases from the literature and add one new case. The mortality in the collected series was 33 per cent. The critical factor in improving survival is early recognition of the pseudomembranous colitis. Most patients can be managed medically by removal of the offending antibiotic, bowel rest, vancomycin, and steroids. If toxic megacolon develops in the face of appropriate medical management, an aggressive surgical approach is indicated, as with ulcerative colitis. Subtotal colectomy appears to be the procedure of choice.
Sixty-six consecutive patients, admitted to St. Vincent's Hospital, Melbourne, with sigmoid volvulus, fell into two groups, 60 without and six with acquired megacolon. In the former group, flatus tube decompression was usually successful, and sigmoid resection provided a cure. In the group with megacolon, the history was longer; patients more often had bowel symptoms before or between acute episodes of volvulus; flatus tube decompression was rarely successful; and symptoms persisted after sigmoidectomy and were sometimes associated with recurrence of volvulus of the new "sigmoid." It seems that nothing less than total colectomy will cure these patients.
BACKGROUND: Toxic megacolon is a life-threatening complication most commonly observed in patients with ulcerative colitis or Crohn's disease that is characterized by total or segmental nonobstructive colonic dilatation of at least 6 cm on plain abdominal films associated with systemic toxicity. CASE REPORT: We report an unusual case of fulminant steroid-refractory ulcerative colitis complicated by toxic megacolon treated successfully with the immunosuppressant tacrolimus. CONCLUSION: Tacrolimus administration induced clinical remission and bridged the time interval, until the standard immunosuppressant azathioprine could maintain clinical remission, thereby avoiding eminent emergency colectomy.
We have studied the resection specimens from 5 patients with idiopathic megarectum and megacolon and 10 control subjects with non-obstructing colonic cancer. Histological staining with haematoxylin and eosin, and immunocytochemical staining for protein gene product 9.5 (PGP9.5), S100 protein, vasoactive intestinal polypeptide (VIP) and calcitonin gene-related peptide (CGRP), and histochemical localization of NADPH diaphorase was performed. The amount of VIP and CGRP present in samples was measured using an enzyme-linked immunosorbent assay. Patients with idiopathic megarectum and megacolon showed hypertrophy of the muscularis mucosae and muscularis externa. The architecture of the innervation as assessed by immunoreactivity for PGP9.5 and S100 protein appeared normal. There was a decrease in the density of innervation of the longitudinal muscle in rectal tissue from patients with idiopathic megarectum, with fewer VIP- and NADPH-diaphorase-containing nerves. In the muscularis mucosae and lamina propria of the rectal samples of patients with idiopathic megarectum, VIP immunoreactivity was higher and more NADPH-diaphorase-containing nerves were seen. CGRP-immunoreactive nerve fibres were only seen in the myenteric plexus. No CGRP-immunoreactive cell bodies were seen. In summary, there is an increase in VIP and nitric oxide containing fibres in the muscularis mucosae and lamina propria and a decrease in the longitudinal muscle in rectal tissue of patients with idiopathic megarectum. Both are NANC (nonadrenergic noncholinergic) inhibitory transmitters in the gut and the possible relationship of the changes in their density with gut function is discussed.
Experience with 12 patients with toxic megacolon that required surgical intervention is described and analyzed. Ten patients had ulcerative colitis and 2 had Crohn's colitis; 9 were treated with corticosteroids before operation. The diagnosis was established by radiologic studies, operative findings and examination of the surgical specimens. The operations performed in these patients were proctocolectomy and ileostomy in five, abdominal colectomy and ileostomy with preservation of the rectum in five, and loop ileostomy and colonic venting in two. All patients had prolonged and complicated recovery periods; 1 died in the postoperative period and 10 reassumed their pre-illness activities. A highly specific therapy program is proposed for managing patients with toxic megacolon.
We report six cases of toxic megacolon in patients with human immunodeficiency virus (HIV). One case, at an early stage of HIV infection, mimicked a severe attack of Crohn's disease, with a negative search for infectious agents. Subtotal colectomy was successfully performed with an uneventful postoperative course. The five other cases concerned patients with acquired immunodeficiency syndrome at a late stage of immunodeficiency. They were related to Clostridium difficile or cytomegalovirus (CMV) intestinal infection in two and three patients, respectively. One case of CMV colitis presented macroscopically and histologically as pseudomembranous colitis. Emergency subtotal colectomy, performed in the first four patients with acquired immunodeficiency syndrome was followed by a fatal postoperative outcome. The last patient treated conservatively by colonoscopic decompression, in association with anti-CMV therapy, had a favorable short-term outcome. From the experience of our series and data from the literature, we discuss the best diagnostic and therapeutic approach to toxic megacolon in patients with HIV.
Computerized tomography was performed on a patient with toxic megacolon. It is conceivable that a patient may be studied by CT prior to plain radiography, and the appearance of the colon described below should alert the examiner to the possibility of toxic megacolon.
Toxic megacolon, its incidence, differential diagnosis, and presenting signs and symptoms are reviewed in this article. The typical histologic and radiographic features are described with a review of the potential triggering factors. An outline of requirements for adequate monitoring of the patient with toxic megacolon is provided. The general management and specific medical management are discussed in detail, and the medical outcome with both medical and surgical intervention is reviewed.
Megacolon is a condition that is not uncommon in the cat. Most cases are idiopathic (a cause cannot be determined), and these seem to be a result of colonic inertia. Pelvic fracture malunions are the next most common cause and result in a pelvic outlet obstruction. Total or subtotal colectomy offers good long-term results in cases of idiopathic megacolon and chronic cases of pelvic fracture malunion, and the technique is described in detail.
A 53 yr old diabetic male presented with a 34% total body surface area (TBSA) deep partial- and full-thickness burns. On post burn days 4 and 9, all of his burns were excised and grafted. Although he had only been treated with topical antibiotics, he developed Clostridium difficile colitis after his second surgery that progressed to Toxic Megacolon and perforation. The incidence and treatment of Toxic Megacolon secondary to C. difficile is reviewed. Early diagnosis and treatment with colonoscopic decompression may obviate the need for surgery.
Acquired megacolon is a chronic disease associated with constipation and malnutrition. Surgical treatment may be required for the alleviation of the intestinal symptoms, emphasizing the interest of nutritional assessment in this population. In a prospective study of 33 patients suffering from acquired megacolon and requiring either anterior resection or pull-through operation, standard anthropometric and biochemical measurements as well as the PNI of Buzby and Mullen were preoperatively assessed. Mean age of the population was 49 +/- 13 y, with 17 males and 16 females. The combined nutritional score indicated 63.6% of the population were malnourished (21/33) of the patients, whereas the Prognostic nutritional index (PNI) revealed 3 high-risk cases (9.1%), 9 with moderate risk (27.3%), and reduced risk for all others. Indeed, 39.4% (13/33) of the patients displayed surgical or septic problems. Chi-square analysis confirmed that both studied criteria were significantly associated with complications (p < 0.05), as morbidity was restricted predominantly to cases with unfavorable Prognostic nutritional index (PNI) results or clear signs of nutritional deficit. Both PNI and conventinoal nutritional assessment are valuable tools for the screening of these surgical candidates. Artificial alimentation was not used in this experience, but deserves consideration in selected patients. Nutritional status improved in the late postoperative period, with normalization of bowel function.
The isolated homeobox gene Enx (Hox11L1) is expressed in enteric neurons innervating distal ileum, and proximal and distal colon. Enx-deficient mice develop megacolon with massive distension of the proximal colon. The number of myenteric ganglia, total neurons per ganglion, and NADPH diaphorase presumptive inhibitory neurons per ganglion are increased in the proximal and distal colon, but decreased in the distal ileum of all Enx-/- mice. Enx-/- mice provide a model for human neuronal intestinal dysplasia (NID), in which myenteric neuronal hyperplasia and megacolon are seen. These results suggest that Enx is required for the proper positional specification and differentiative cell fate of enteric neurons.
AIM: The aetiology of idiopathic megarectum and idiopathic megacolon is unknown. We postulated that biochemical or ultrastructural abnormalities may be pathologically important, as has been observed in patients with chronic idiopathic intestinal pseudo-obstruction. METHODS AND RESULTS: Resection specimens from five patients with idiopathic megarectum or megacolon were processed for paraffin wax-embedded tissue histology (haematoxylin and eosin, Gomori trichrome and picrosirius stains, phosphatase activity and periodic acid-Schiff staining), and frozen tissue for histochemistry and electron microscopy. The antibodies used in the immunohistochemistry were to myosin light chain kinase, smooth muscle myosin, alpha and beta actins, filamin, tropomyosin, phosphorylated and dephosphorylated neurofilaments and N-CAM. Variable hypertrophy of the muscularis mucosae and externa, no atrophy, and a variable nerve density decrease in longitudinal muscle and increase in the lamina propria was seen. In one patient beta actin and myosin light chain kinase immunoreactivity was reduced. CONCLUSION: Variable changes in innervation, and an abnormal contractile protein immunoreactivity pattern in one patient, may be of pathogenic importance. These clinically homogeneous conditions are likely to be due to a range of underlying pathogenic abnormalities. A search for further specific biochemical abnormalities is justified.