Radiology of small bowel obstruction: contemporary approach and controversies.

The radiologic workup of patients with known or suspected small bowel obstruction and the timing of surgical intervention in this complex situation have undergone considerable changes over the past two decades. The diagnosis and treatment of small bowel obstruction, a common clinical condition often associated with signs and symptoms similar to those seen in other acute abdominal disorders, continue to evolve. This article examines the changes related to the use of imaging in the diagnosis and management of patients with this potentially dangerous problem and revisits pertinent controversies.

Does the addition of an oral barium tracer improve the ability of the preliminary abdominal radiograph to assess efficacy of colonic cleansing? A prospective randomized controlled evaluation.

BACKGROUND: We investigated whether the ability of preliminary abdominal radiography to assess the adequacy of colonic preparation is improved by the addition of an oral barium tracer to the laxative preparation and the optimal dosage of this tracer. METHODS: A single-blind, randomized controlled evaluation of four parallel groups of adult patients was performed. All patients were scheduled to a receive a double-contrast barium enema at a tertiary care hospital or an outpatient clinic. RESULTS: One hundred nineteen patients were randomized into four groups. There was no significant difference in the ability of plain abdominal radiography to predict the adequacy of the bowel preparation between the control group and the groups given 60 or 150 g of barium tracer. There was an improved correlation between findings of preliminary abdominal radiography and the adequacy of colon preparation between the control group and the group given 240 g of oral barium tracer (67% vs. 90%). CONCLUSION: The use of a large amount (240 g) of oral barium tracer with the colonic preparation improves the ability of preliminary abdominal radiography to predict the adequacy of colonic cleansing.

Malignant melanoma: patterns of metastasis to the small bowel, reliability of imaging studies, and clinical relevance.

OBJECTIVES: The aims of this study were to determine the frequency of different patterns of melanoma metastases to small bowel on radiological examination, and to assess the reliability of the most commonly used radiological methods for detecting these lesions. METHODS: The records of cases archived as melanoma metastatic to the small bowel of the Armed Forces Institute of Pathology were reviewed. The clinical information, type of imaging procedure performed, and radiological features were analyzed and compared to the findings at surgery and at autopsy. RESULTS: A total of 32 patients had clinical and surgical data with pathological confirmation. Seven patients had metastasis involving the duodenum, 22 had jejunal involvement, and 11 had ileal involvement. Metastases were categorized as polypoid, cavitary, infiltrating, or exoenteric. The polypoid pattern was seen in 20 patients (63%), six of whom showed multiple polypoid lesions (>10), referred to as polyposis. The "target lesion," a discrete polypoid mass with a central ulceration, was observed in only three (9%) of the 32 patients. Eight patients (25%) demonstrated a cavitary pattern, a circumferential mass with inner marginal necrosis, and five (16%) showed an infiltrating pattern. One patient (3%) had an exoenteric lesion with a fistulous tract. The small bowel follow-through demonstrated 32 of 55 metastases (sensitivity 58%). Contrast-enhanced CT demonstrated 32 of 48 masses (sensitivity 66%). Of the six cases of malignant polyposis, none were identified using CT, and only two were diagnosed by small bowel follow-through. CONCLUSIONS: The polypoid pattern, equally distributed between the jejunum and ileum, is the most common manifestation of metastatic melanoma to the small bowel. The target lesion was infrequently seen in this series. Small bowel follow-through and conventional CT seem to be unreliable in demonstrating melanoma metastases to the small bowel.

Small-bowel obstruction: optimizing radiologic investigation and nonsurgical management.

Small-bowel obstruction is an old and common problem. Like most illnesses, its diagnosis and treatment continue to evolve. The radiologic approach to the investigation of small-bowel obstruction and the timing of surgical intervention have undergone considerable changes during the past decade. In this review, the authors analyze the recently described radiologic techniques used in the examination of patients with suspected mechanical small-bowel obstruction, revisit the controversy of the short versus long decompression tube, and provide insights on how to optimize the radiologic investigation and nonsurgical management of small-bowel obstruction.

Barium trapping in rectoceles: are we trapped by the wrong definition?

BACKGROUND: Barium trapping within a rectocele is a criterion used by surgeons to select which patients with rectoceles should undergo operative repair. This proctographic study compared the presence and depth of barium trapping within a rectocele on postevacuation radiography with those seen on posttoilet radiography after further evacuation in the privacy of the bathroom. METHODS: Eighty-two consecutive patients with evidence of barium trapping on postevacuation radiographs of a fluoroscopic dynamic cystoproctographic examination were reviewed retrospectively. The size of the rectoceles and the depth of barium trapping on the postevacuation and subsequent posttoilet radiographs were measured. RESULTS: The posttoilet radiographs showed resolution of the barium trapping in 47 (57%) of the 82 patients. Resolution of the trapping was directly related to rectocele size. The mean differences in the depth of barium trapping between the postevacuation and posttoilet radiographs were significant for all sizes of rectocele. CONCLUSION: Barium trapping in rectoceles changes with the degree of rectal evacuation. More complete evacuation was shown on the posttoilet radiograph than on the postevacuation radiograph. Consequently, the posttoilet radiograph may be more appropriate for the preoperative assessment of barium trapping within rectoceles.

Female pelvic organ prolapse: a comparison of triphasic dynamic MR imaging and triphasic fluoroscopic cystocolpoproctography.

OBJECTIVE: This study compared dynamic MR imaging with fluoroscopic cystocolpoproctography for the detection and measurement of prolapse of pelvic organs. SUBJECTS AND METHODS: Ten patients underwent triphasic dynamic MR imaging and triphasic fluoroscopic cystocolpoproctography with identical amounts of contrast material to opacify the bladder, vagina, and rectum. The dynamic MR imaging procedure included cine-loop presentation. Each examination was analyzed to determine the presence and extent of prolapse of pelvic organs based on specific measurements. RESULTS: Both dynamic MR imaging and fluoroscopic cystocolpoproctography revealed 10 rectoceles (mean extents, 2.85 and 2.45 cm, respectively). Nine cystoceles were revealed by both dynamic MR imaging (mean extent, 4.05 cm) and fluoroscopy (mean extent, 4.55 cm). Seven enteroceles were revealed, one of which was initially not seen on dynamic MR imaging. Two sigmoidoceles were revealed, one of which was not seen on fluoroscopy. The mean extent of the enteroceles and sigmoidoceles on dynamic MR imaging was 3.50 cm, and the mean extent on fluoroscopy was 4.25 cm. Nine of the 10 patients were able to defecate in the supine position on the MR imaging table. Patients were divided equally in their preference for dynamic MR imaging or fluoroscopic cystocolpoproctography. CONCLUSION: Triphasic dynamic MR imaging and triphasic fluoroscopic cystocolpoproctograpy show similar detection rates for prolapse of pelvic organs. Although dynamic MR imaging underestimates the extent of cystoceles and enteroceles, it has the advantage of revealing all pelvic organs and the pelvic floor musculature in a multiplanar cine-loop presentation.

Female pelvic organ prolapse: diagnostic contribution of dynamic cystoproctography and comparison with physical examination.

OBJECTIVE: The aim of this study was to assess the contribution of dynamic cystoproctography to the evaluation of female pelvic organ prolapse and to compare this contribution with that of physical examination. MATERIALS AND METHODS: The presence or absence of rectocele, enterocele, sigmoidocele, and cystocele on physical examination and on cystoproctography was retrospectively analyzed in 170 consecutive patients. For each of these diagnostic methods, organ prolapse was graded as small, moderate, or large on the basis of specific, defined measurements. RESULTS: A rectocele was detected by proctography in 155 patients (91%); 119 (77%) of these rectoceles were also found on physical examination. Barium trapping at proctography was related to rectocele size. Proctography showed an enterocele in 47 patients (28%); 24 (51%) of these enteroceles were also found on physical examination. Physical examination also found 44 enteroceles that could not be corroborated radiologically. At proctography, the enteroceles were relatively large, extending an average of 7.3 cm below the vaginal apex. Eight patients had sigmoidoceles, none of which were found on physical examination. A cystocele was shown by cystoproctography in 159 patients (94%); 132 (83%) of these cystoceles were also found on physical examination. CONCLUSION: The correlation between finding prolapsed pelvic organs on dynamic cystoproctography and finding them on physical examination varies. Most radiographically detected rectoceles and cystoceles are found on physical examination, whereas the correlation for enteroceles and sigmoidoceles is poor. Dynamic cystoproctography provides direct visualization and quantification of female pelvic organ prolapse, information that usually can only be inferred by physical examination.

Association of compartment defects in pelvic floor dysfunction.

OBJECTIVE: Dynamic cystoproctography was used to determine the frequency of associated urinary, genital, and anorectal abnormalities in women with pelvic floor dysfunction. SUBJECTS AND METHODS: We categorized, by pelvic floor compartments, the symptoms at presentation of 100 consecutive female patients who had been referred for dynamic cystoproctography. We then analyzed the compartment defects seen on dynamic cystoproctography relative to those detected on clinical presentation. RESULTS: Of the 20 patients with symptoms of anterior compartment (urinary) defect, dynamic cystoproctography revealed that 45% had vaginal vault prolapse of more than 50% and that 90% had rectoceles. Of the 45 patients with symptoms of middle compartment (genital) defect, dynamic cystoproctography revealed that 91% had cystoceles, 56% had a hypermobile bladder neck, 82% had rectoceles, 58% had enteroceles, 11% had sigmoidoceles, 20% had rectoanal intussusception, and 16% had anal incontinence. Of the 17 patients with symptoms of posterior compartment (anorectal) defect, dynamic cystoproctography showed that 71% had cystoceles, 65% had a hypermobile bladder neck, and 35% had vaginal vault prolapse of more than 50%. Of the 18 patients with symptoms of defects from a combination of compartments, dynamic cystoproctography revealed that 89% had cystoceles, 56% had a hypermobile bladder neck, 39% had vaginal vault prolapse exceeding 50%, 100% had rectoceles (of which 45% were large), 6% had enteroceles, 6% had sigmoidoceles, 22% had rectoanal intussusception, and 6% had anal incontinence. CONCLUSION: Although patients may present with symptoms that involve only one compartment, a multicompartment prolapse is usually revealed on dynamic cystoproctography. Of the patients with pelvic floor dysfunction, 95% had abnormalities in all three compartments.

Reliability and role of plain film radiography and CT in the diagnosis of small-bowel obstruction.

OBJECTIVE: We compare the reliability and define the role of plain film radiography and CT in the assessment of various severities of small-bowel obstruction. MATERIALS AND METHODS: A blinded retrospective analysis was done on 78 patients who underwent plain abdominal radiography, CT, and enteroclysis to assess for suspected small-bowel obstruction. The findings at enteroclysis and the clinical outcomes were used as standards of reference. RESULTS: The sensitivity of plain film radiography for revealing small-bowel obstruction was 69% (44/64), and its specificity was 57% (8/14). Overall accuracy of plain film radiography was 67% (52/78). The sensitivity and specificity of CT were 64% (41/64) and 79% (11/ 14), respectively. Overall accuracy of CT was 67% (52/78). When obstructions were classified as low- and high-grade partial obstruction, plain film radiography and CT had sensitivities of 86% (24/28) and 82% (23/28), respectively, for high-grade obstruction and 56% (20/36) and 50% (18/36), respectively, for low-grade obstruction. CT revealed the cause of the small-bowel obstruction in 95% (39/41) of those patients in who CT correctly showed the obstruction. CONCLUSION: Plain film radiography and CT had similar overall accuracies in showing small-bowel obstruction of various severities. Plain film radiography should remain the initial method of imaging patients with suspected small-bowel obstruction. The ability of CT to show the cause of small-bowel obstruction makes CT an important additional diagnostic tool when specific management issues must be addressed.

Current status of small bowel radiography.

BACKGROUND: In the past, small bowel examinations were usually ordered for the sake of "completeness." As a result, small bowel radiography was performed casually and without attention to detail. This review examines pertinent clinical issues and the recent contribution of small bowel radiography to the evaluation and management of the patient with suspected small bowel disease. Recommendations for the clinical utilization of small bowel radiography are discussed. METHODS: Analysis of pertinent citations addressing valid indications for, and technique of, small bowel radiography from 1980 to July 1995 through a computerized bibliographic search (Medline and Current Contents). RESULTS: Accepted clinical indications for small bowel radiography include (1) unexplained gastrointestinal bleeding, (2) possible small bowel tumor, (3) small bowel obstruction, (4) Crohn disease, and (5) malabsorption. The current literature reflects the limitations of the conventional small bowel follow-through, various modifications to improve its clinical yield, the important contribution of enteroclysis in the workup, and subsequent management of patients with possible small bowel disease. A controversy in the radiology literature exists as to whether to use the small bowel follow-through or enteroclysis as the primary method of examining the small bowel. CONCLUSION: The thoughtful selection of patients by clinicians for small bowel radiography is essential to make radiologic evaluation cost effective. The incidence of disease of the small intestine is low and is associated with nonspecific symptoms. Because of the inherent difficulty of visualizing numerous loops of an actively peristalsing bowel, a reliable imaging method is needed that not only detects small or early structural abnormality but also accurately documents normalcy. The yield of information provided by enteroclysis and its high negative predictive value suggests that it should be the primary method for small bowel examination. The "overhead"-based conventional small bowel follow-through should be abandoned. The "fluoroscopy"-based small bowel follow-through augmented when necessary by the peroral pneumocolon or the gas-enhanced double-contrast follow-through method is an acceptable alternative when enteroclysis is not possible.

Radiologic features of carcinomas arising in hiatal hernias.

OBJECTIVE: The aim of this study was to present the spectrum of clinical and radiologic manifestations of carcinomas that originate within hiatal hernias, to emphasize their increasing prevalence among the elderly patient population, and to assess the reasons for radiologic misdiagnosis. MATERIALS AND METHODS: Medical records and radiologic studies of 27 adult patients (15 men and 12 women; 54-83 years old [mean, 71 years old]) with surgically proven adenocarcinomas in the herniated proximal part of the stomach were reviewed. RESULTS: A hiatal hernia with intrinsic abnormalities suggestive of carcinoma was shown by upper gastrointestinal tract examination obtained before surgery in all 27 patients. A diagnosis of malignancy was reported at the time of examination for 24 patients (89%); for the remaining three patients, diagnosis was made by endoscopy. The predominant feature, seen in 15 patients (56%), was an infiltrative process that caused deformity and rigidity of the hiatal hernia in conjunction with thickened, nodular mucosa. The intrahernial tumor appeared as a well-demarcated sessile polyp or lobulated mass in nine patients (33%) and as ulcerations and eccentric wall thickening in three patients (11%). All errors were perceptive in nature. On review, we saw minimal evidence of infiltration or small polypoid masses. CONCLUSION: Although some of the radiologic abnormalities were minimal, our review of 27 cases in a biphasic upper gastrointestinal tract series resulted in detectable radiographic findings of carcinomas associated with hiatal hernias for all cases. Meticulous assessment of the herniated fundus and gastroesophageal regions is crucial for the detection of such tumors.

Discomfort during double-contrast barium enema examination: a placebo-controlled double-blind evaluation of the effect of glucagon and diazepam.

PURPOSE: To evaluate the effectiveness of glucagon and diazepam as compared with placebo in decreasing abdominal discomfort in patients during double-contrast barium enema examination. MATERIALS AND METHODS: Thirty-six men (n = 9) and women (n = 27) aged 21-62 years with "a lot or terrible discomfort" during double-contrast barium enema examination were randomized into double-blind groups of 12 patients each at the onset of examination. Each group received a placebo, glucagon (1 mg), or diazepam (5 mg) intravenously. Discomfort was scored on a four-point scale by the patients. RESULTS: Repeated measures analysis of variance findings indicated that those who received an active drug reported significantly (P = .001) greater relief of discomfort. Discomfort scores improved, on average, 2.2 in the glucagon, 2.0 in the diazepam, and 1.2 in the placebo groups. Colonic spasm did not correlate with abdominal discomfort. CONCLUSION: Discomfort during double-contrast barium enema examination can be statistically significantly diminished with a hypotonic agent or a sedative.