Clive I. Bartram

Anal-Sphincter Disruption during Vaginal Delivery

Background Lacerations of the anal sphincter or injury to sphincter innervation during childbirth are major causes of fecal incontinence, but the incidence and importance of occult sphincter damage during routine vaginal delivery are unknown. We sought to determine the incidence of damage to the anal sphincter and the relation of injury to symptoms, anorectal physiologic function, and the mode of delivery. Methods We studied 202 consecutive women six weeks before delivery, 150 of them six weeks after delivery, and 32 with abnormal findings six months after delivery. Symptoms of anal incontinence and fecal urgency were assessed, and anal endosonography, manometry, perineometry, and measurement of the terminal motor latency of the pudendal nerves were performed. Results Ten of the 79 primiparous women (13 percent) and 11 of the 48 multiparous women (23 percent) who delivered vaginally had anal incontinence or fecal urgency when studied six weeks after delivery. Twenty-eight of the 79 primiparous women (35 p...

Prospective study of the extent of internal anal sphincter division during lateral sphincterotomy

PURPOSE: The aim of lateral internal anal sphincterotomy when treating anal fissure is to divide the distal one-third to one-half of the internal anal sphincter. This study aimed to evaluate prospectively the extent of disruption to the internal anal sphincter following lateral anal internal sphincterotomy and also to establish the prevalence of symptoms of anal incontinence in these patients. METHODS: Fifteen patients with anal fissure (ten females and five males) had bowel symptoms assessed and anal endosonography performed preoperatively and two months after lateral internal anal sphincterotomy. RESULTS: Anal endosonography was normal preoperatively in all but two females who had anterior external sphincter defects (presumedly from previous obstetric trauma). Postoperatively, apart from one male in whom no defect could be identified, all had an internal anal sphincter defect corresponding to the site of lateral internal anal sphincterotomy. In nine of the ten females, the defect involved the full length of the internal anal sphincter, but in the other four males, the defect involved the distal internal anal sphincter only. All were continent preoperatively, but after lateral internal anal sphincterotomy, three females became incontinent to flatus (two of whom had a preoperative external sphincter defect). CONCLUSION: In contrast to lateral internal anal sphincterotomy in males, division of the internal anal sphincter in most females tends to be more extensive than intended. This is probably related to their shorter anal canal. In some females, lateral internal anal sphincterotomy may compromise sphincter function and precipitate anal incontinence, particularly in the presence of other sphincter defects. Care should be exercised especially in the presence of previous obstetric trauma, as internal anal sphincter division may further compromise sphincter function.

Primary degeneration of the internal anal sphincter as a cause of passive faecal incontinence

BACKGROUND Faecal incontinence is usually attributed to pelvic-floor denervation of striated muscle or direct sphincter trauma. We have identified a cause of passive faecal incontinence related to degeneration of the internal anal sphincter smooth muscle, in the absence of denervation, structural damage, external-sphincter weakness, or sensory abnormalities. METHODS Patients were included on the basis of: passive faecal incontinence, no urge faecal incontinence, low anal pressure whilst at rest, normal anal-squeeze pressure, endosonographically confirmed circumferentially intact internal and external anal sphincters, and normal pudendal nerve terminal nerve latencies. In a second analysis done to assess the proportion of patients with this disorder, we recorded the cause of incontinence in consecutive patients seen during a 6-month period. FINDINGS 45 patients (35 women, median age 63 years, range 23-80 years) fulfilled the diagnostic criteria. Median duration of symptoms was 2 years (3 months to 20 years). Nine of the 35 women were nulliparous. The median resting anal pressure was 40 cm water (16-56 cm water, normal > 60 cm water). Endosonography revealed an internal sphincter that was thin and hyperechogenic, and had a poorly defined edge. The normal increase in the thickness of the internal anal sphincter with age was not seen. Anal-squeeze pressure, sensitivity, and pudendal nerve latencies were normal. In the second analysis the condition was identified in eight of 230 patients, representing 4% of new referrals. INTERPRETATION Primary degeneration of the internal anal sphincter smooth muscle is a discrete clinical condition causing passive faecal incontinence.

Magnetic resonance imaging of fistula-in-ano.

PURPOSE: Successful management of anal fistulas depends upon accurate assessment of the primary tract and any secondary extensions. Preoperative imaging has, to date, been disappointing. METHODS: A prospective study of 35 patients with a clinical diagnosis of fistula-in-ano was performed comparing magnetic resonance imaging with the independently documented operative findings. Magnetic resonance imaging was also compared with anal endosonography in 20 patients. RESULTS: Magnetic resonance imaging is accurate and demonstrates pathology missed at surgery by experienced coloproctologists. Magnetic resonance imaging is superior to anal endosonography. CONCLUSIONS: Magnetic resonance imaging is advocated as the method of choice when imaging is required for anal fistulas.

Why is colonoscopy more difficult in women

BACKGROUND In our experience colonoscopy in women is more difficult than in men. A retrospective review of 2194 colonoscopies performed by a single experienced endoscopist (CBW) showed that 31% of examinations in women were considered technically difficult compared with 16% in men. METHODS To investigate a possible anatomic basis for this finding, normal barium enema series from 183 female and 162 male patients were identified. From these barium enemas, measurements of colonic length and mobility were independently taken by two physicians who were unaware of each patients gender. RESULTS Total colonic length was greater in women (median, 155 cm) compared to men (median, 145 cm), p = 0.005, despite womens smaller stature (p < 0.0001). Although there were no significant differences in rectum plus sigmoid, descending, or ascending plus cecum segmental lengths, women had longer transverse colons (female median length, 48 cm; male median length, 40 cm), p < 0.0001. There were no differences in mobility of the descending colon and transverse colon between the sexes, but the transverse colon reached the true pelvis more often in women (62%) than in men (26%), p < 0.001. CONCLUSIONS Colonoscopy appears to be a technically more difficult procedure in women. The reason for this may be due in part to an inherently longer colon.

Effect of MRI on clinical outcome of recurrent fistula-in-ano

Recurrent fistula-in-ano is usually due to sepsis missed at surgery, which can be identified by MRI. We aimed to establish the therapeutic effect of MRI in patients with fistula-in-ano. We did MRI in 71 patients with recurrent fistula, with further surgery done at the discretion of the surgeon. Surgery and MRI agreed in 40 patients, five (13%) of whom had further recurrence, compared with 16 (52%) of 31 in whom surgery and MRI disagreed (p=0.0005). Further recurrence in all 16 was at the site predicted by MRI. For surgeons who always acted on MRI, further recurrences arose in four of 25 (16%) operations versus eight of 14 (57%) operations for those who ignored imaging (p=0.008). Surgery guided by MRI reduces further recurrence of fistula-in-ano by 75% and should be done in all patients with recurrent fistula.

Unsuspected sphincter damage following childbirth revealed by anal endosonography

Anal endosonography was performed in 62 consecutive patients with incontinence of flatus or faeces following obstetric trauma, and in 18 parous controls. Of the incontinent group, 90% had defects in the external sphincter, 65% in the internal sphincter and 44% disruption of the perineal body, compared with none of the controls. This triad of lesions is pathognomonic of obstetric trauma. Anal endosonography revealed a higher prevalence of sphincter damage than expected from anorectal physiology tests, and therefore has a role in screening patients following complicated or difficult deliveries.

CT colonography: effect of experience and training on reader performance

The purpose of this paper was to investigate the effect of radiologist experience and increasing exposure to CT colonography on reader performance. Three radiologists of differing general experience (consultant, research fellow, trainee) independently analysed 100 CT colonographic datasets. Readers had no prior experience of CT colonography and received feedback and training after the first 50 cases from an independent experienced radiologist. Diagnostic performance and reporting times were compared for the first and second 50 datasets and compared with the results of a radiologist experienced in CT colonography. Before training only the consultant reader achieved statistical equivalence with the reference standard for detection of larger polyps. After training, detection rates ranged between 25 and 58% for larger polyps. Only the trainee significantly improved after training (P=0.007), with performance of other readers unchanged or even worse. Reporting times following training were reduced significantly for the consultant and fellow (P<0.001 and P=0.03, respectively), but increased for the trainee (P<0.001). In comparison to the consultant reader, the odds of detection of larger polyps was 0.36 (CI 0.16, 0.82) for the fellow and 0.36 (CI 0.14, 0.91) for the trainee. There is considerable variation in the ability to report CT colonography. Prior experience in gastrointestinal radiology is a distinct advantage. Competence cannot be assumed even after directed training via a database of 50 cases.

Automated Insufflation of Carbon Dioxide for MDCT Colonography: Distension and Patient Experience Compared with Manual Insufflation

OBJECTIVE The purpose of our study was to compare the effects of automated and manual carbon dioxide insufflation before CT colonography on distention and patient acceptance. SUBJECTS AND METHODS One hundred forty-one symptomatic subjects underwent CT colonography using either an automated device (n = 47) or a manual method (n = 94) for carbon dioxide insufflation. CT data sets were assessed retrospectively in consensus by two blinded observers who graded distention for six colonic segments using a 4-point scale. An additional assessment of the overall clinical adequacy of distention (yes/no) was also made, and any learning curve was sought. Each patient completed a validated 24-point patient questionnaire reflecting patient satisfaction and discomfort. Distention scores, clinical adequacy, and questionnaire responses were analyzed using ordered logistic regression, Fishers exact test, and the Mann-Whitney test statistic, respectively. RESULTS Automated insufflation significantly improved distention overall (p = 0.001). For individual segments, distention was significantly improved in the sigmoid (p = 0.007) and descending (p < 0.001) colons when the patient was supine; and in the sigmoid (p = 0.02), descending (p = 0.001), and transverse (p = 0.02) colons when supine and prone positions were combined. No significant difference was seen in the clinical adequacy of distention, nor was there evidence of any learning curve for either insufflation method. Subjects were more weary after automated insufflation (p = 0.03), but no significant difference was seen for the remaining 23 questionnaire items or for feelings of bloating or discomfort. CONCLUSION Automated carbon dioxide insufflation significantly improves colonic distention compared with manual insufflation. Benefit is greatest in the left colon, particularly when the patient is supine. Patient acceptance is similar to that for manual insufflation.

Colorectal Tumor Vascularity: Quantitative Assessment with Multidetector CT—Do Tumor Perfusion Measurements Reflect Angiogenesis?

PURPOSE To establish the relationships between quantitative perfusion computed tomography (CT) parameters-specifically, primary tumor blood flow, blood volume, transit time, and permeability surface-area product-and immunohistologic markers of angiogenesis in colorectal cancer. MATERIALS AND METHODS After institutional review board approval and informed patient consent were obtained for this prospective study, 23 patients (11 men, 12 women; mean age, 68.4 years; age range, 34.8-87.1 years) with colorectal adenocarcinoma underwent a 65-second perfusion CT examination, and tumor blood flow, blood volume, mean transit time, and permeability surface-area product were determined. After surgery, resected specimens were sectioned and stained immunohistochemically to identify CD34 for quantification of microvessel density (MVD), to identify smooth muscle actin for assessment of pericyte coverage index, to identify vascular endothelial growth factor (VEGF), and to identify glucose transporter protein (GLUT-1). Perfusion CT measurements were correlated with MVD, pericyte coverage index, VEGF expression, and GLUT-1 expression by using Pearson or Spearman rank correlation analysis, with significance assigned at the 5% level. RESULTS Mean blood flow, blood volume, transit time, and permeability surface-area product values were 72.1 mL/min/100 g of tissue +/- 28.4 (standard deviation), 6.2 mL/100 g of tissue +/- 1.4, 9.3 seconds +/- 3.9, and 13.9 mL/min/100 g of tissue +/- 3.2, respectively. Blood volume (r = 0.59, P = .002) and permeability surface-area product (r = 0.46, P = .03) correlated positively with MVD, but blood flow (r = 0.27, P = .22) and transit time (r = -0.18, P = .44) did not. There were no significant associations between any perfusion CT parameter and pericyte coverage index (r <or= 0.36, P > .05), VEGF score (rho <or= 0.30, P >or= .15), or GLUT-1 score (rho < 0.21, P >or= .33). CONCLUSION Tumor permeability surface-area product and blood volume correlate positively with MVD and may reflect the microvascularity of colorectal tumors.