Commentary: imaging of anorectal function.
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Anal Canal↗
Biomedical subjects
S Halligan
Publications and source records attributed to S Halligan.
Vaginal endosonography to diagnose enterocoele.
Radiological diagnosis of enterocoele is possible using evacuation proctography, but the standard technique must be modified to reveal the small bowel. Since prolapsed bowel is interposed between the vagina and rectum, diagnosis may be possible using vaginal endosonography. We describe a simple ultrasound technique to diagnose enterocoele, which has been validated by comparison with proctography. 17 women were examined with vaginal endosonography, and a diagnosis of enterocoele made if bowel was visualized in the rectovaginal space when bearing down. The findings were compared with subsequent proctography. In eight cases (47%) bowel prolapsed into the rectogenital space during straining, obscuring the rectum, while this did not occur in the remaining nine subjects (53%). Proctography confirmed an enterocoele in six of the eight cases in whom it had been diagnosed on endosonography, and confirmed the absence of enterocoele in all of the nine cases negative on endosonography. These values gave vaginal endosonography a sensitivity of 100% and specificity of 82%, with a positive predictive value of 75%, and negative predictive value of 100% for a prevalence of abnormality of 0.35. Vaginal endosonography is a quick, easy and convenient alternative to evacuation proctography for the radiological diagnosis of enterocoele.
Adult↗
Enterocele revealed by simultaneous evacuation proctography and peritoneography: does "defecation block" exist?
OBJECTIVE: Pelvic floor weakness may allow prolapse of the bowel into the rectogenital space, forming an enterocele. Enteroceles are believed to obstruct defecation by rectal compression and are therefore considered an abnormal finding on evacuation proctography. With a technique combine evacuation proctography and peritoneography, we prospectively studied constipated patients to reveal the pelvic peritoneal recesses during evacuation and to determine if enterocele actually impairs rectal emptying. SUBJECTS AND METHODS: Fifty constipated patients were studied prospectively, Using 20 ml of water-soluble contrast medium, we performed peritoneography, then evacuation protography with 120 ml of intrarectal paste. Lateral evacuation and posteroanterior stress views were analyzed by computerized video capture. Anatomic features and functional measurements of rectal emptying were noted. Posteroanterior views were compared with views in 31 subjects undergoing peritoneography for investigation of groin pain. RESULTS: Technical failure in three patients left 47 for analysis. A deep rectogenital pouch was seen in 36 patients (77%). Of these, 12 (58%) contained viscera that formed an enterocele, but the remaining 15 patients (42%) showed no visceral filling. Most pouches were apparent only during straining (31 cases, 86%). Peritoneal descent was greater than in controls (p < .0001), of whom only three had small rectogenital pouches. Patients with enterocele were compared with those who had a rectogenital pouch but no visceral filling and those who had no pouch. Standard anatomic measurements by evacuation proctography were not significantly different, but patients with enterocele evacuated more rapidly (p = .008) and completely (p = .021) than did the other two groups. CONCLUSION: Combined evacuation proctography and peritoneography is a new technique to diagnose pelvic hernias that occur during evacuation. This technique has shown that a deep rectogenital pouch is common in constipated patients and that just over half such pouches fill with viscera. However, because an enterocele does not impair rectal evacuation, this proctographic finding should be interpreted with caution.
Adolescent↗
Cranial MR imaging in Wilson's disease.
OBJECTIVE: The purpose of the study was to describe the range of abnormalities seen on cranial MR images of patients with Wilson's disease and correlate the findings with clinical severity, duration of disease, and duration of neurologic signs and symptoms before treatment. In those patients with serial studies, the changes on MR images were compared with the clinical response. SUBJECTS AND METHODS: Twenty-five patients with Wilson's disease underwent MR imaging of the brain using conventional spin-echo sequences (n = 25), phase maps (n = 8), and partially refocused interleaved multiple-echo sequences (n = 5). RESULTS: MR imaging findings were abnormal in 22 patients and normal in three patients. The basal ganglia were interpreted as abnormal in 19 (86%) of 22 patients, involving the putamen in 19 (86%), the thalami in 12 (54%), the caudate head in 10 (45%), and the globus pallidus in nine (41%). We found a predilection for involvement of the outer rim of the putamen and the ventral nuclear mass of the thalami. The claustrum was abnormal in three patients. The midbrain was abnormal in 17 (77%) of these 22 patients, affecting predominantly the tegmentum but also the substantia nigra, red nuclei, inferior tectum, and crura. The pons was abnormal in 18 (82%) of 22 patients, and the cerebellum was abnormal in 11 patients (50%), with involvement of the superior and middle cerebellar peduncles. Atrophy was present in 18 (82%) of 22 patients, and cortical white matter changes were apparent in 13 (59%) of 22 patients. The scan of one untreated patient revealed shortening of the T1 relaxation time in the thalami, which was consistent with the paramagnetic effects of copper. Phase maps and partially refocused interleaved multiple-echo sequences performed in eight and five patients, respectively, and used to reveal a susceptibility change induced by iron or copper showed normal findings. We found a significant inverse relationship between severity, but not extent, of change in signal intensity and the length of untreated disease (p = .030) and the total duration of disease (p = .015). The study group was too small to show a correlation with clinical findings. Changes seen on MR images matched the clinical response to treatment in only two of the seven patients who underwent follow-up studies. CONCLUSION: MR imaging revealed abnormalities in the basal ganglia, cerebral white matter, midbrain, pons, and cerebellum. The paramagnetic effects of copper were detected only in untreated patients. Patients with a longer duration of disease had less severe changes in signal intensity. MR imaging was of limited value in follow-up.
Adolescent↗
Transperineal repair of symptomatic rectocele with Marlex mesh: a clinical, physiological and radiologic assessment of treatment.
BACKGROUND: The aim of this study was to evaluate the operative repair of rectoceles in a defined group of women by a technique designed to deal with the cause (failure of the rectovaginal septum) rather than the effect (rectal and vaginal wall bulging). STUDY DESIGN: Only women whose defecation was aided by vaginal digitation and who had large rectoceles on proctography were included. Any other clinical symptoms in the absence of vaginal digitation, even when proctography demonstrated a rectocele, were not taken as indicators for surgery in this study. There were nine women, median age 50 years (range, 32 to 61). The rectovaginal septum was repaired with Marlex mesh through a perineal approach by one surgeon. The median follow-up period was 29 months. RESULTS: Eight of the nine women achieved successful evacuation after surgery without the need for vaginal digitation. Rectocele size, depth, and the percent of barium trapped in the rectocele on proctography were all improved. Anorectal physiology measurements were unchanged by surgery. CONCLUSIONS: Operative repair of the rectovaginal septum removes the need for vaginal digitation in most women with large rectoceles on proctography. Further studies in well-defined groups of women are needed to establish how well rectocele repair aids women with a variety of other pelvic and perineal symtoms.
Adult↗
Proctographic changes after rectopexy for solitary rectal ulcer syndrome and preoperative predictive factors for a successful outcome.
Rectopexy is advocated as treatment for solitary rectal ulcer syndrome despite variable outcome. Sixteen patients with this condition, who remained symptomatic after surgery, were examined before and after operation by evacuation proctography and compared with a matched group of seven patients whose symptoms had been relieved, to investigate the effect of rectopexy on rectal configuration or emptying, or both, and to identify any preoperative factor associated with a good outcome. Rectal prolapse, demonstrated in 19 of 23 patients before operation (internal in 12, external in seven), was seen in only one patient after surgery. The rectal axis became more vertical at rest (median 44 degrees before operation versus 35 degrees after surgery, P = 0.006) and on evacuation (median 38 degrees versus 31 degrees, P = 0.023). Preoperative evacuation time was increased in patients with poor outcome (median (range) 22 (8-60)s versus 10 (5-15)s, P = 0.008). Rectopexy successfully treats rectal prolapse in patients with solitary rectal ulcer syndrome and alters rectal configuration. These features, however, are unrelated to outcome. Prolonged preoperative evacuation time, suggesting a defaecatory disorder, may predict poor symptomatic outcome.
Adolescent↗
Endosonography of the anal sphincters in solitary rectal ulcer syndrome.
Twenty-one patients with histologically proven solitary rectal ulcer syndrome (SRUS) were examined by anal endosonography (AES) in order to determine the frequency of any ultrasound abnormality. Comparison was made with a group of 17 age and sex matched asymptomatic subjects. Four patients with SRUS had anal sphincter defects on AES. All were of the internal anal sphincter (IAS), which appeared fragmented in two patients with complete rectal prolapse. Measurements of internal and external anal sphincter (EAS) diameter and cross-sectional area were taken, excluding the 4 patients with defects. The submucosa was inhomogeneous (P = 0.0016) and thickness increased in patients with SRUS (median 4.0 mm vs 2.0 mm; P < 0.0001). IAS diameter was increased (median 3.8 mm vs 2.0 mm; P < 0.0001), as was cross-sectional area (median 241 sq mm vs 112 sq mm; P < 0.0001). EAS diameter was also increased (median 8.5 mm vs 7.0 mm; P = 0.0173), as was cross-sectional area (median 905 sq mm vs 594 sq mm; P = 0.0052). The ratio of EAS to IAS thickness was reduced in patients with SRUS (median 2.6 vs 4.0; P = 0.0029). The mechanism of these changes is unclear but apparent muscle hypertrophy on ultrasound may diagnose those patients with SRUS in whom defecatory difficulty is a predominant symptom.
Adult↗
A peroperative comparison of Western and Oriental colonic anatomy and mesenteric attachments.
It has been suggested that the Oriental colon is easier to colonoscope than its Western counterpart. The aim of this study was to investigate possible differences in colonic anatomy between Western and Oriental patients that might explain this observation. Measurements of colonic length and mesenteric attachments were taken according to a set protocol from 115 Western (Caucasian) and 114 Oriental patients at laparotomy. Sigmoid adhesions were found more frequently in Western (17%) compared to Oriental (8%) patients, P = 0.047. A descending mesocolon of > or = 10 cm occurred in 10 (8%) Western patients but only 1 (0.9%) Oriental patient, P = 0.01. The splenic flexure was more frequently mobile in Western patients (20%) compared to Oriental (9%) patients, P = 0.016. In 29% - of Western patients the mid-transverse colon reached the symphysis pubis, or lower when pulled downwards in contrast to 10% of Oriental patients, P < 0.001. There was no significant difference in total colonic length comparing Western (median = 114 cm, range 68-159 cm) to Oriental (median = 111 cm, range 78-161 cm) patients. Western patients have a higher incidence of sigmoid colon adhesions and increased colonic mobility when compared to Orientals. These findings support the observation that colonoscopy is a more difficult procedure in Western patients.
Adult↗
Is barium trapping in rectoceles significant?
PURPOSE: This study was designed to determine whether rectocele size and contrast retention are significant. METHODS: Evacuation proctography and simultaneous intrarectal pressure measurements from a small, noncompliant balloon catheter were performed in three matched groups of 11 constipated female patients with rectoceles, rectoceles and contrast trapping of > 10 percent, and no rectocele. Computerized image analysis was used to measure rectocele area and evacuation. RESULTS: In the two groups with rectoceles, there was no significant difference in rectocele area or width pre-evacuation. The anorectal angle, pelvic floor descent, maximum anal canal width, evacuation time or completeness, maximum and distal intrarectal pressure, or need to digitate did not differ significantly between the groups. In seven patients with barium trapping (64 percent) the intrarectal pressure dropped abruptly as the balloon entered the rectocele, suggesting that trapping results from sequestration into the vagina, closing part of the rectocele from the normal intrarectal pressure zone. CONCLUSION: Because no impairment of evacuation appears to be associated with either a large rectocele or trapping, these evacuation problems should not be directly attributed to these proctographic findings.
Barium Sulfate↗
A study of the nephrotoxicity of three cephalosporins in rabbits using 1H NMR spectroscopy.
Male New Zealand White rabbits received a single intravenous injection of 125 mg/kg cephaloridine, 500 mg/kg cefoperazone or 1000 mg/kg cephalothin. Histological examination of kidneys at 48 h post-dose confirmed the presence of bilateral necrosis of the proximal convoluted tubules in the cephaloridine-treated animals. 1H-NMR urinalysis of cephaloridine-treated rabbits detected drug-related resonances, decreased hippurate and increased glucose at 0-24 h post-dose accompanied by elevated levels of lactate, glycine, citrate, glutamine/glutamate and alanine at 24-48 h post-dose. No histopathological changes were observed following administration of cefoperazone or cephalothin. 1H-NMR spectra of urine collected from these animals showed drug-related resonances and decreased hippurate levels at 0-24 h post-dose, and increased glucose levels at 24-48 h post-dose. Analysis of urine by conventional clinical-chemistry failed to reveal any statistically significant differences between the treatment groups. Under the conditions of this study, the nephrotoxic effects of cephaloridine and the minimal effects of cefoperazone and cephalothin could be clearly distinguished by 1H-NMR urinalysis but not by conventional urinalysis.
Alanine↗
The radiological investigation of constipation.
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Constipation↗
Can barium enema indicate when colonoscopy will be difficult?
The barium enemas of 48 consecutive patients, who were technically difficult to intubate at colonoscopy, were compared to those of 46 patients who were not. Measurements were taken of colonic length and mobility, and an assessment made of diverticular disease. Rectosigmoid length (mean difficult group = 61 cm, mean control = 54 cm, P = 0.01) and total colonic length (mean difficult group = 157 cm, mean control = 140 cm, P < 0.0001) were greater in the difficult colonoscopy group as were transverse colon mobility (mean difficult group = 10 cm, mean control = 7 cm, P = 0.003) or redundancy (transverse colon reaching the true pelvis on the erect film); 65% difficult group vs 17% control group, P < 0.0001. The presence of moderate or severe diverticular disease was also greater in the difficult (23%) compared to the control (4%) group, P = 0.02. When available, assessment of a previous barium enema is a useful guide to probable technical difficulty of colonscopy. It may allow appropriate allocation of potentially difficult cases to specialist endoscopy lists.
Adolescent↗
The role of small bowel radiology in the diagnosis and management of Crohn's disease.
A total of 50 children with Crohn's disease were examined by barium follow-through and colonoscopy with ileoscopy, to determine the value of small bowel radiology. Of these children, 40 (80%) had evidence of small bowel Crohn's disease on ileoscopy and/or barium follow-through. Twenty-two (44%) had disease confined to the terminal ileum. Radiology diagnosed disease proximal to the terminal ileum in 18 cases (36%), including 5 children in whom the terminal ileum was normal. Ileoscopy was not possible in nine patients (18%), six of whom had small bowel disease on barium follow-through. Colonic involvement, demonstrated in 34 (68%), was the sole site of disease in 6 (12%). Fifteen (30%) children had surgery, which in six (12%) was determined by the radiological findings of complicated small bowel disease. As the terminal ileum may be uninvolved in the presence of proximal ileal disease, normal ileoscopy does not exclude small bowel Crohn's disease. Small bowel radiology remains necessary to assess the full extent of Crohn's disease in children.
Adolescent↗
Intrarectal pressures and balloon expulsion related to evacuation proctography.
Seventy four patients with constipation were examined by standard evacuation proctography and then attempted to expel a small, non-deformable rectal balloon, connected to a pressure transducer to measure intrarectal pressure. Simultaneous imaging related the intrarectal position of the balloon to rectal deformity. Inability to expel the balloon was associated proctographically with prolonged evacuation, incomplete evacuation, reduced anal canal diameter, and acute anorectal angulation during evacuation. The presence and size of rectocoele or intussusception was unrelated to voiding of paste or balloon. An independent linear combination of pelvic floor descent and evacuation time on proctography correctly predicted maximum intrarectal pressure in 74% of cases. No patient with both prolonged evacuation and reduced pelvic floor descent on proctography could void the balloon, as maximum intrarectal pressure was reduced in this group. A prolonged evacuation time on proctography, in combination with reduced pelvic floor descent, suggests defecatory disorder may be caused by inability to raise intrarectal pressure. A diagnosis of anismus should not be made on proctography solely on the basis of incomplete/prolonged evacuation, as this may simply reflect inadequate straining.
Catheterization↗
The quest for a more acceptable bowel preparation: comparison of a polyethylene glycol/electrolyte solution and a mannitol/Picolax mixture for colonoscopy.
Eighty-nine consecutive patients attending for day-case colonoscopy were randomly allocated either polyethylene glycol/balanced electrolyte (PEG) mixture (n = 45) or a mannitol/Picolax mixture (n = 44). Both preparations were administered in two fractions. Patients recorded their experience of the preparation on a questionnaire and one of two experienced endoscopists (unaware of the type of preparation given) assessed the result of bowel cleansing. Carbon dioxide insufflation was used for all examinations. Good/excellent bowel cleansing occurred in significantly more patients given PEG, 43 (96%), than those allocated mannitol/Picolax, 34 (77%), p = 0.01. More patients receiving mannitol/Picolax were able to complete the preparation in full than patients receiving PEG (38 vs 27, p = 0.01). More patients found the taste of mannitol/Picolax pleasant compared to PEG (46% vs 20%). Both preparations had a similar side-effect profile. Of those patients tested, 13% receiving mannitol/Picolax had a postural drop in blood pressure and blood parameters suggestive of mild dehydration. A fractionated administration of PEG as a bowel preparation for day-case colonoscopy is well tolerated and superior as a cleansing agent to a mannitol/Picolax combination. Provided carbon dioxide is used as the insufflating agent, mannitol/Picolax is an acceptable alternative in fit, young patients intolerant of PEG.
Administration, Oral↗
Proctographic features of anismus.
PURPOSE: To document the proctographic features of anismus at evacuation proctography and determine the optimum radiologic measurements for diagnosis. MATERIALS AND METHODS: Twenty-four patients with anismus according to clinical and multiple physiologic criteria were examined with evacuation proctography. Structural and functional measurements were compared with those of a group of 20 asymptomatic subjects. RESULTS: No significant difference between patients and control subjects was found with respect to pelvic descent, rectocele, or any anorectal angle measurement. In patients with anismus, initiation of evacuation was prolonged (median, 9 vs 3 seconds for control subjects; P < .0001) and anal canal width was reduced (median, 0.6 vs 1.2 cm; P = .0075). Evacuation time was increased (median, 50 vs 10 seconds; P < .0001), and the percentage of contrast material evacuated was decreased (median, 60% vs 100%; P < .0001). Only four patients were able to evacuate more than 66% of the contrast material within 30 seconds, whereas all control subjects were able to do so. CONCLUSION: Measurement of the anorectal angle to diagnose anismus should be abandoned. Patients with anismus demonstrate delayed initiation of evacuation, which is also prolonged and incomplete. Incomplete evacuation after 30 seconds is highly suggestive of anismus.
Adult↗
Evacuation proctography in patients with solitary rectal ulcer syndrome: anatomic abnormalities and frequency of impaired emptying and prolapse.
OBJECTIVE: Solitary rectal ulcer syndrome is characterized by rectal bleeding, tenesmus, and difficult evacuation. Evacuation proctography can be used in patients with solitary rectal ulcer syndrome to diagnose associated internal or external rectal prolapse and delayed or incomplete rectal emptying. The objective of this study was to determine the proctographic abnormalities and the frequency of rectal prolapse and incomplete or delayed emptying in a large group of patients with solitary rectal ulcer syndrome. MATERIALS AND METHODS: Proctographic examinations of 53 patients with histologically proved solitary rectal ulcer syndrome were reviewed retrospectively. Evacuation proctography was done by a standard technique. The rate and completeness of rectal emptying and structural abnormality of the rectum were recorded. Comparison was made with a control group of 20 subjects who had no anorectal symptoms. RESULTS: Fourteen patients (26%) with solitary rectal ulcer syndrome had rectal irregularity at rest compared with none in the control group. Rectal prolapse developed on evacuation in 36 patients (68%) with solitary rectal ulcer syndrome: internal prolapse in 24 patients (45%), and external prolapse in 12 (23%). Descent of the pelvic floor on evacuation was greater in the solitary rectal ulcer syndrome group (median, 4.4 cm; range, 0-10.0 cm) than in the control group (median, 3.3 cm; range, 0.6-5.3 cm; p = .006). Thickened rectal folds were seen in 11 (55%) of 20 patients with solitary rectal ulcer syndrome examined with posteroanterior proctography. Evacuation was prolonged and incomplete in patients with solitary rectal ulcer syndrome (median, 15 sec; range, 3-60 sec) compared with control subjects (median, 10 sec; range, 3-30 sec; p = .012). All control subjects evacuated more than two thirds of the contrast material in less than 30 sec compared with only 41 patients with solitary rectal ulcer syndrome (77%). Overall, evacuation proctography disclosed delayed or incomplete emptying and/or rectal prolapse in 40 patients (75%) with solitary rectal ulcer syndrome compared with two control subjects who showed low-grade internal rectal prolapse only (p < .0001). CONCLUSION: Solitary rectal ulcer syndrome is significantly associated with prolonged and incomplete evacuation and with an increased prevalence of internal and external rectal prolapse.
Adolescent↗
Extinction of within-event learning is contextually controlled and subject to renewal.
Five experiments examined within-event learning in rats by inducing an appetite for one of the elements (salt) of a compound stimulus and assessing preference for the other element (almond). Almond preference was conditional upon (1) the almond flavour having been presented in compound with the salt, and (2) the assessment being conducted when the rats were out of sodium balance (Experiment 1). Presentations of the compound in one environment (A) and of the salt and almond elements in a second environment (B) resulted in greater almond preference when rats were tested in A than in B (Experiment 2). Almond preference was reduced when separate presentations of the compound and almond (Experiment 3) or of the compound and salt (Experiment 4) occurred in the same environments but not when these presentations occurred in different environments. Rats exposed to the compound in A and then extinguished to the elements in either A or B showed a reduced almond preference when tested in the extinction environment, but not when tested in the other environment (Experiment 5). Thus, extinction of within-event learning is context-specific and subject to renewal. The results were interpreted in terms of an associative model whereby separate presentations of the elements result in a symmetrical inhibitory link which is contextually gated (Bouton, 1993).
Animals↗