Biomedical subjects
Publications and source records attributed to R Kerremans.
We determined the maximum closing capability of the internal anal sphincter muscle ring in vitro and in vivo. The internal sphincter, 4 to 6 mm thick, cannot close the anal canal hermetically, not even during maximal contraction. The blood-filled anal cushions have to fill up an intrasphincteric gap of at least 7 to 8 mm in diameter.
The human IAS has particular structural and functional characteristics. This smooth muscle constantly generates rhythmic electrical slow waves, but no action potentials. The slow waves are linked to calcium fluxes and both are essential for mechanical activity, i.e. the ASPW. The IAS is pharmacologically characterized by the presence of alpha excitatory and beta inhibitory adrenergic receptors. Cholinergic drugs have an indirect effect through the release of an inhibitory neurotransmitter, very probably VIP, from NANC nerves. The myogenic activity of the IAS is enhanced by its extrinsic sympathetic innervation. Thus, at rest, the IAS is in a state of partial tetanus and contributes approximately 55% of the MABP. Because the IAS ring cannot be completely closed, the anal mucosa and the haemorrhoidal plexuses fill the gap. By compressing these tissues, the IAS perfectly closes the anal canal to retain not only solids but also fluid stool and gas. Acute rectal distension and rectal activity, mainly through intramural pathways, induce reflex IAS relaxation, permitting the rectal contents to be sampled by receptors in the upper anal canal while continence is temporarily maintained by EAS activity and by expansion of the haemorrhoidal cushions. There is a correlation between the volume of rectal distension and the parameters of IAS relaxation. At maximal IAS relaxation, ASPW are absent, indicating the completeness of the inhibition. Although this RAIR is not essential for defecation, insufficient relaxation may be implicated in constipation. Hyperactivity of the IAS resulting in a high MABP and AUSPW has been considered both as a cause and as an effect in haemorrhoids and anal fissure. Continence for fluids and gas is impaired if IAS activity is decreased (i.e. a low MABP), either by direct trauma or by damage of its sympathetic innervation. Severe faecal incontinence will develop when the contractility of both the IAS and the EAS is affected.
We present two cases of acute colonic pseudo-obstruction, one complicated with perforation. Orthopedic surgery was the pathogenetic factor in both cases. Recovery was successful in both patients after appropriate treatment. The importance of conventional X-ray techniques, and more specially the plain X-ray of the abdomen, is stressed regarding early diagnosis and follow-up.
Aphthous lesions recur in the neoterminal ileum within the first few months after curative resection of the distal ileum in patients with Crohn's disease. These lesions do not originate from microscopic disease that is already present at the time of surgery. To investigate the importance of faecal stream in the pathogenesis of recurrent Crohn's lesions, we have studied 5 patients with Crohn's disease who had ileal resection. After curative resection and ileocolonic anastomosis, a diverting terminal ileostomy was constructed 25-35 cm proximal to the anastomosis thereby excluding the neoterminal ileum, the anastomosis, and the colon from intestinal transit. After six months of exclusion, endoscopy of the ileocolon was undertaken and biopsy specimens were taken. Transit was then restored. Six months after reanastomosis further biopsy specimens were taken. These patients were compared with a control group of 75 patients with Crohn's disease who underwent a one-step ileal resection and ileocolonic anastomosis. None of the 5 patients had endoscopic lesions in the neoterminal ileum after six months of exclusion and biopsies did not show inflammatory changes characteristic of Crohn's disease. By contrast, 53 of 75 patients with one-step surgery had endoscopic recurrence in the neoterminal ileum within six months of surgery. All 5 patients had an important recurrence of disease, both endoscopically and histologically, at ileocolonoscopy six months after reanastomosis. Our findings strongly support the view that recurrence of Crohn's disease in the neoterminal ileum after curative ileal resection is dependent on faecal stream.
Anismus, paradoxical external sphincter function, spastic pelvic floor syndrome, rectoanal dysnergia, abdomino-levator incoordination for abdominopelvic asychronism, are all due to paradoxical contraction of the striated sphincter apparatus during voiding and is characterised by prolonged and excessive straining at stool. Biofeedback is the treatment of choice and has to be introduced at an early stage. We present the results of an ambulatory approach based on the integration of simulated balloon defaecation with small (50 ml) as well as constant rectal sensation volume, defaecometry and anal manometry. The pathophysiology visualised by the patient's own anorectal pressure recordings on the screen of a personal computer is explained and corrected. Sixteen patients were treated and followed for at least 1 year. Manometric data were normal except for an increased minimum residual pressure and rectal compliance. Nine patients could not evacuate a 50 ml bolus initially. Simulated defaecation became possible in seven out of these nine patients when the bolus was increased up to the individual constant rectal sensation volume. Two patients could not evacuate this volume either, while defaecation was made much less laborious in the other seven patients. Paradoxical contraction was immediately corrected in 7/16 cases. Also, as an immediate, objective benefit of a single training session, improved defaecation of a 50 ml bolus was observed in 11 patients. This effect was preserved after 6 weeks in nine cases; symptomatic recurrence did not occur in these patients during follow-up. This method of defaecation training has many advantages as compared with sphincter training using EMG electrodes eventually performed in the absence of a desire to defaecate or in lying position.(ABSTRACT TRUNCATED AT 250 WORDS)
Seven experts drew the rectal axes of 18 representative proctographic images on two occasions, with a 1-year interval, in order to assess intraobserver variation in the determination of the anorectal angle (ARA). Intraobserver variation (6%) and interobserver variation (17%) were smallest when the central rectal axis was used to determine the ARA. A strong relation was found between inter- and intraobserver variation (r = 0.77). Intraobserver variation tended to be rather small for pictures made during straining, but a relation with the magnitude of the ARA was not found. Although none of the seven experts could reproduce the rectal axes with less than or equal to 10% variation in all 18 pictures, redrawing of the central rectal axis delivered less than or equal to 10% variation in 86% of determinations. It is concluded that intraobserver variation is influenced by the expertise of the investigator, the method of analysis, and the anorectal configuration to be analyzed. Radiologic assessment of the ARA may yield reliable data on the dynamics of the anorectum if performed by a single investigator on x-ray films that allow confident analysis.
Twelve selected patients undergoing cholecystectomy were operated in a prospective randomised study by laparoscopy (CO2 laser) or by classic surgery. Our preliminary results suggest that laparoscopic cholecystectomy is of clinical benefit as compared to classic cholecystectomy since it reduces the surgical trauma, limiting weight loss and shortening the hospital stay.
Determination of the anorectal angle (ARA) and the position of the pelvic floor is, theoretically, very important in understanding the mechanisms of anorectal continence and defaecation. The variability in the measurement of the ARA was analyzed. Nine experts drew ther rectal axis either as a line along the posterior wall of the distal rectum or as the central axis of the rectal lumen on the outlines of 18 representative proctographic images. The standard deviations and ranges of the mean values of each ARA were comparable but large in both methods. On average, the S.D. was 8 degrees and the range value about 23 degrees. Inter-observer variation was not related to the magnitude of the ARA, but rather to the anorectal configuration. Drawing a line along the posterior distal rectal wall is difficult when it is irregular or when the puborectalis impression is indistinct. The central rectal axis is difficult to draw when the junction between the upper and lower rectum is ill defined or when the outlines of the distal rectum are asymmetric e.g. by the presence of a rectocele. Thus, the variability of both methods was not strongly interrelated (r = 0.68 for the median values). It is concluded that, in general, radiologic assessment of the ARA is not reliable enough for comparative investigation of the dynamics of the anorectum.
Eighty-nine patients who had been treated by ileal resection for Crohn's disease between 1979 and 1984 were included in a prospective cohort follow up to study the natural course of early postoperative lesions. Recurrent lesions were observed endoscopically in the neoterminal ileum within 1 year of surgery in 73% of the patients, although only 20% of the patients had symptoms. Three years after surgery, the endoscopic recurrence rate had increased to 85% and symptomatic recurrence occurred in 34%. The ultimate course of the disease was best predicted by the severity of the early postoperative lesions, as observed at ileoscopy. Clinical parameters that influenced outcome were preoperative disease activity, the indication for surgery, and the number of surgical resections. When patients were stratified for preoperative disease activity, the severity of lesions found at endoscopy remained a strong predictive factor for symptomatic recurrence. In 22 other patients submitted to "curative" ileal resection and ileocolonic anastomosis, the segment to be used as neoterminal ileum was carefully examined during surgery, and two large biopsies were taken before making the anastomosis. An ileoscopy was performed 6 months after surgery. Although all patients had a macroscopically normal neoterminal ileum and 19 had entirely normal biopsies at the time of surgery, 21 patients were found at ileoscopy to have developed ileitis involving a 15-cm segment (range, 4-30 cm), and 20 had unequivocal microscopic lesions on biopsies. These studies suggest that early lesions in the neoterminal ileum after Crohn's resection do not originate from microscopic inflammation present in this bowel segment at the time of surgery. The early postoperative lesions in the neoterminal ileum seem to be a suitable model to study the pathogenesis of Crohn's disease and also to evaluate new therapeutic modalities, either to prevent development of these early lesions or to treat progressive recurrence.
The alterations of several small-intestinal mucosal enzymes have been examined in cats that underwent different periods (1-4 hr) of occlusion of the superior mesenteric artery, followed by 4 hr of reperfusion. The damage progressed during ischemia and reperfusion from the villus tips to the crypts: first, there was a rapid decrease in the activity of maltase, a brush-border enzyme; a slower decline occurred in two cytoplasmic enzymes, aldolase A (with preferential location in feline villus cells) and lactate dehydrogenase (with an ubiquitous distribution); a lag preceded the decrease in aldolase B (a cytoplasmic enzyme shown to occur mainly in feline crypt cells). For all these enzymes, the initial period of reperfusion was associated with a greater decrease in enzyme activity than persisting ischemia. By determination of the unsedimentable proportion of glutamate dehydrogenase (a mitochondrial matrix enzyme) and of acid phosphatase (a lysosomal enzyme) it was demonstrated that ischemia caused important mitochondrial damage before the cells were lost, whereas no lysosomal damage was observed in any condition. These sensitive parameters of cell damage can serve as a criterion for an adequate evaluation of potential cytoprotective agents.
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Acute abdominal complications of systemic lupus erythematodes requiring laparatomy are not frequent. A 30-year-old man with systemic lupus erythematodes developed a necrotizing enteritis of the small bowel with pneumatosis intestinalis. Only one case of intestinal vasculitis associated with systemic lupus erythematodes has previously been reported. Presence of intramural gas in the small bowel and of gas in the portal vein was detected on plain abdominal film and confirmed by subsequent CT examination. Since corticosteroids often mask the severity of the disease, radiological evaluation is essential to the overall management of the patient with intestinal vasculitis. Due to the observed radiological signs, emergency laparotomy was performed. Histologic examination revealed necrotizing enteritis due to vasculitis.
The maximal anal basal pressure (MABP) was measured with probes of 0.3, 1, 2 and 3 cm diameter in 21 subjects, 60 years old, without anal pathology. The components of MABP were analyzed by inducing a maximal internal sphincter (IS) relaxation, taking pressure measurements in the conscious state and during narcosis with curarization. In seven cases pressure measurements were done on isolated anorectum after abdominoperineal rectum amputation. MABP increases with probe diameter before as well as during anaesthesia with curarization. The contribution of the striated sphincter tonic activity is constant within the range of probe diameters used. At rest, i.e. when the 0.3 cm diameter pressure recording probe is used, 30% of MABP is made up by striated sphincter tonic activity, 45% of it is due to nerve induced IS activity, 10% to purely myogenic IS activity and 15% can be attributed to the expansion of the haemorrhoidal plexuses. Although MABP is mainly based on active forces generated by the smooth and striated sphincter apparatus, the presence of the anal cushions is essential for perfect anal continence, as they have to fill the gap within the IS ring to hermetically close the anal canal. The global IS activity, contributing 50-60% of MABP at rest, can completely be inhibited by a maximal rectoanal inhibitory reflex. Stretching of passive elements starts at 1 cm anal distension, but steeply increases thereafter, accounting for 65% of the MABP at 3 cm anal distension. It is deduced that optimal stool diameter is about 2 cm.
Lactate dehydrogenase has been measured in the small-intestinal mucosa in order to assess its value as a marker for the effects of ischemia and of reperfusion. The decrease in specific activity of the enzyme illustrates the deleterious effect of reperfusion on the quality of the remaining epithelial cells. However, this parameter fails to detect the loss of epithelial cells, which is the major event during ischemia as well as during reperfusion. In contrast, the expression of enzyme activity per g protein of the underlying intestinal muscle allowed us, in addition, to assess quantitatively the loss of epithelial cells, in good agreement with the histological data.
The early occurrence of peritoneal signs and hyperamylasemia in a 14-year-old boy, who had fallen off his horse, urged us to perform a sonographic and computed tomographic study of the upper abdomen. Both examinations showed a complete pancreatic rupture. Distal pancreatectomy led to a rapid and uneventful recovery.
Three patients are described with hepatic involvement by Echinococcus granulosus, complicated by spontaneous rupture into the biliary tract. Clinical features consisted of upper abdominal pain, jaundice, fever, anorexia, and vomiting. Hepatomegaly and marked epigastric tenderness were consistently observed. Laboratory findings included obstructive liver function tests, leucocytosis, eosinophilia, and hyperamylasemia. Abdominal computed tomography, showing the cystic wall, the presence of wall calcifications, daughter cysts and wall enhancement, provided a correct diagnosis of hepatic hydatidosis in all patients. Dilatation of the bile ducts with the presence of intraluminal material was clearly shown by sonography and endoscopic retrograde cholangiography. These abnormalities were most frequently found in the common bile duct and in the left hepatic duct. On sonography, the intraluminal material appeared as amorphous, sludge-like hydatid sand, and as daughter cysts. On ERCP, the intrabiliary parasitic material appeared as non-homogeneous, irregularly shaped and mobile filling defects. Other findings at ERCP were displacement and distortion of intrahepatic bile ducts by the hepatic cysts and a mild dilatation of the pancreatic duct. In one occasion, evacuation of a daughter cyst through the papilla was observed. The therapeutic value of mebendazole and endoscopic sphincterotomy in our patients is discussed.
We describe a young man with a hitherto unreported association of chronic ulcerative colitis, primary sclerosing cholangitis (PSC), bile duct carcinoma, and generalized sarcoidosis with features of high-intensity alveolitis. This finding suggests that common immunological mechanisms may be involved in the pathogenesis of these diseases.