A prospective study on the use of water-soluble contrast follow-through radiology in the management of small bowel obstruction

Pearls and Pitfalls of Imaging Small Bowel Obstruction

Small bowel obstruction (SBO) is a common condition encountered by radiologists in the evaluation of patients with abdominal pain, and is an important diagnosis to be comfortable with given substantial associated morbidity and mortality. In this review, we summarize an imaging approach to evaluating patients with suspected SBO, discuss the role of certain imaging modalities such as radiography and small bowel follow through, CT, and MRI, as well as review some common and also less common causes of SBO such as internal hernia. We will also discuss tailoring the imaging approach to address specific clinical questions and special patient populations such as imaging the pregnant patient with suspected SBO, and the inflammatory bowel disease patient.

THE WATER-SOLUBLE CONTRAST FOR ADHESIVE SMALL BOWEL OBSTRUCTION: ARE THERE ADVANTAGES?

BACKGROUND

Adhesive small bowel obstruction is one of the most common causes of surgical emergencies, representing about 15% of hospital admissions. Defining the need and timing of surgical intervention still remains a challenge.

AIMS

To report the experience of using meglumine-based water-soluble contrast in a tertiary hospital in southern Brazil, comparing with the world literature.

METHODS

Patients suspected of having adhesive small bowel obstruction, according to their clinical conditions, underwent an established protocol, consisting of the administration of water-soluble contrast, followed by plain abdominal radiograph within 12 hours and by a new clinical evaluation. The protocol was initiated after starting conservative management, including fasting and placement of a nasogastric tube, as well as intravenous fluid reposition.

RESULTS

A total of 126 patients were submitted to the protocol. The water-soluble contrast test sensitivity and specificity after the first radiograph were 94.6 and 91.0%, respectively; after the second radiograph, these values were 92.3 and 100%. The general test values for sensitivity and specificity were 91.9 and 100%, respectively.

CONCLUSIONS

The measure parameters evaluated in this study were similar to those found in the literature, contributing to endorse the importance of this test in the evaluation of patients with adhesive small bowel obstruction. The particular relevance of this study was the similar results that were found using a different type of meglumine-based contrast, which is available in Brazil.

The Effect of Hyperosmolar Water-Soluble Contrast for the Management of Adhesive Small Bowel Obstruction: A Systematic Review and Meta-Analysis

OBJECTIVE

To better understand the efficacy of water-soluble contrast (WSC) in the treatment of adhesive small bowel obstruction (SBO).

BACKGROUND

Guidelines recommend using WSC to treat adhesive SBO nonoperatively by acting as a cathartic agent. The evidence supporting this practice is mixed.

METHODS

A systematic review and meta-analysis of published articles describing the effect of WSC compared with control treatments was performed for the period of January 1, 1990 to November 1, 2021. Study quality was assessed using the Cochrane risk-of-bias and the Newcastle-Ottawa tools. The therapeutic effect of WSC was assessed by operative rates and hospital length of stay (HLOS) in nonsurgical patients.

RESULTS

The initial search yielded 4879 articles, of which, 28 were selected for full text review. We identified 11 eligible randomized controlled trials (RCTs) which included 817 patients and 9 observational studies of 3944 patients. HLOS in nonsurgical patients decreased by 1.95 days (95% confidence interval: 0.56-3.3) in the RCTs and could not be assessed in the observational studies. WSC did not significantly affect operative rates in the RCTs (19.8% vs. 21.4%) but did reduce rates in the observational studies (11% vs. 16%, risk ratio: 0.56, 95% confidence interval: 0.39-0.82).

CONCLUSION

WSC studies may reduce HLOS for patients who have SBO and do not require surgery. However, the current literature is heterogenous with considerable design limitations. High-quality RCTs are needed using standardized protocols to determine the full benefit of WSC for the management of SBO.

Non-operative Management of Small Bowel Obstruction in Patients with No Previous Abdominal Surgery: A Systematic Review and Meta-analysis

While the contemporary management of adhesive small bowel obstruction (SBO) often includes a trial of non-operative management (NOM), surgical dogma dictates urgent operative exploration in patients without previous abdominal surgery. This dogma has been challenged by recent evidence suggesting most obstructions in this population are adhesive in nature. The objectives of this review were to evaluate the feasibility of NOM in patients with SBO and no history of previous abdominal surgery, to examine the etiologies of SBO in this population, and to explore the rate of adverse events seen following NOM. Embase, Medline, Cochrane, and Google Scholar were searched from inception to September 24, 2019. Articles reporting on NOM for SBO in patients without previous abdominal surgery and without clinical or radiographic features necessitating an emergent operation were included. Data were combined to obtain a pooled proportion of patients discharged without operation following a trial of NOM. 6 studies reporting on a total of 272 patients were included. The pooled proportion of patients discharged following NOM was 49.5% (95% CI 23.7-75.3%). Adhesions were found to be the predominant cause of obstruction. NOM did not appear to increase short-term complications. Most SBOs in patients without previous abdominal surgery are adhesive in nature and many patients can be discharged from hospital without surgery. While the short-term outcomes of NOM are acceptable, future studies are needed to address the long-term outcomes and safety of NOM as a treatment strategy for SBO in patients without previous abdominal surgery.

Efficacy of Gastrografin® Compared with Standard Conservative Treatment in Management of Adhesive Small Bowel Obstruction at Mulago National Referral Hospital

INTRODUCTION

The treatment of adhesive small bowel obstruction is controversial, with both operative and non-operative management practiced in different centers worldwide. Non-operative management is increasingly getting popular, though operative rates still remain high. A study to compare the efficacy of an oral water-soluble medium (Gastrografin®) with standard conservative management, both non-operative methods, in the management of this condition was conducted in a tertiary Sub Saharan hospital.

METHODS

An open randomised controlled clinical trial was conducted between September 2012 and March 2013 at Mulago National Referral and Teaching Hospital, Uganda. Fifty patients of both genders, with adhesive small bowel obstruction, in the hospital's emergency and general surgical wards were included. Randomisation was to Gastrografin® and standard conservative treatment groups. The primary outcomes were: the time interval between admission and relief of obstruction, the length of hospital stay, and the rates of operative surgery.

RESULTS

All 50 recruited patients were followed up and analysed; 25 for each group. In the Gastrografin® group, 22 (88%) patients had relief of obstruction following the intervention, with 3 (12%) requiring surgery. The conservative treatment group had 16 (64%) patients relieved of obstruction conservatively, and 9 (36%) required surgery. The difference in operative rates between the two groups was not statistically significance (P = 0.67). Average time to relief of obstruction was shorter in the Gastrografin® group (72.52 hrs) compared to the conservative treatment group (117.75 hrs), a significant difference (P = 0.023). The average length of hospital stay was shorter in the Gastrografin® group (5.62 days) compared to the conservative treatment group (10.88 days), a significant difference (P = 0.04).

CONCLUSION

The use of Gastrografin® in patients with adhesive small bowel obstruction helps in earlier resolution of obstruction and reduces the length of hospital stay compared with standard conservative management. Its role in reducing the rate of laparotomies remains inconclusive.

Evaluation and management of small-bowel obstruction: an Eastern Association for the Surgery of Trauma practice management guideline

BACKGROUND

Small-bowel obstruction (SBO) represents as many as 16% of surgical admissions and more than 300,000 operations annually in the United States. The optimal strategies for the diagnosis and management of SBO continue to evolve secondary to advances in imaging techniques, critical care, and surgical techniques. This updated systematic literature review was developed by the Eastern Association for the Surgery of Trauma to provide up-to-date evidence-based recommendations for SBO.

METHODS

A search of the National Library of Medicine MEDLINE database was performed using PubMed interface for articles published from 2007 to 2011.

RESULTS

The search identified 53 new articles that were then combined with the 131 studies previously reviewed by the 2007 guidelines. The updated guidelines were then presented at the 2012 annual EAST meeting.

CONCLUSION

Level I evidence now exists to recommend the use of computed tomographic scan, especially multidetector computed tomography with multiplanar reconstructions, in the evaluation of patients with SBO because it can provide incremental clinically relevant information over plains films that may lead to changes in management. Patients with evidence of generalized peritonitis, other evidence of clinical deterioration, such as fever, leukocytosis, tachycardia, metabolic acidosis, and continuous pain, or patients with evidence of ischemia on imaging should undergo timely exploration. The remainder of patients can safely undergo initial nonoperative management for both partial and complete SBO. Water-soluble contrast studies should be considered in patients who do not clinically resolve after 48 to 72 hours for both diagnostic and potential therapeutic purposes. Laparoscopic treatment of SBO has been demonstrated to be a viable alternative to laparotomy in selected cases.

Role of water soluble contrast agents in assigning patients to a non-operative course in adhesive small bowel obstruction

OBJECTIVES

Adhesive small bowel obstruction (SBO) is a common surgical emergency. It is estimated that at least 60% of SBO are due to post-operative adhesions. Water soluble contrast agents (gastrografin) have been used to identify patients who might be treated non-operatively. This study aims to determine the role of gastrografin in adhesive intestinal obstruction patients.

METHODS

In this prospective study, 27 patients admitted between 1(st) August 2004 and 1(st) July 2006 with clinical signs suggestive of postoperative adhesive SBO met the inclusion criteria. After intravenous hydration, nasogastric tube insertion and complete suctioning of the gastric fluid, 100 ml of gastrograsfin was given and plain abdominal radiography was taken 6 hours and 24 hours if the contrast is not seen in the colon. Those in whom the contrast reached the colon in 24 hours were considered to have partial SBO and started oral intake. If gastrografin failed to reach the colon in 24 hours and the patient did not improve in the following 24 hours, laparotomy was performed.

RESULTS

Conservative treatment was successful in 31 cases (91%) and 3 (9%) required operation. Patients treated conservatively had short hospital stay (mean=4 days) and tolerated oral feeding with no morbidity or mortality.

CONCLUSION

Oral gastrografin helps in the management of patients with postoperative adhesive SBO.

Developing a new measure of small bowel peristalsis with dynamic MR: a proof of concept study

BACKGROUND

Small bowel peristalsis is a complex of many individual motion elements. Although each element of peristalsis can be measured there is no current global measure of peristalsis.

PURPOSE

To examine the feasibility of automated computerized assessment of global small bowel motility using simple computational methods.

MATERIAL AND METHODS

Coronal dynamic MR images were obtained from five healthy volunteers who had fasted for 9 h and drunk 1.5 L of water. Images were taken using single breath-hold and ECG triggering. Acquisitions were repeated at 10 and 20 min after an intramuscular injection of hyoscine butylbromide. Parametric maps were generated representing the mean change in signal amplitude (MSA) per voxel for each dynamic acquisition. Two observers independently assessed thresholding for optimal segmentation of small bowel from other sources of signal. Total voxel activity (TVA) for each study was calculated as a sum of MSA per slice and whole examination and TVA profiles were generated.

RESULTS

Independent observations suggest that the automated segmentation method described usefully segments small bowel activity from other signal. Small bowel movement represented as TVA varied three-fold in the five volunteers and was inhibited by anti-muscarinic injection.

CONCLUSION

It is possible to develop a new measure, based on automated segmentation of mean signal amplitude changes, of small bowel peristalsis using dynamic MR.

Impact of gastrografin in clinical practice in the management of adhesive small bowel obstruction

BACKGROUND

Gastrografin (GG) has been shown to accelerate the resolution of adhesive small bowel obstruction (ASBO) and decrease length of stay (LOS) in hospital. Consequently, we instituted a protocol recommending the routine use of GG in patients with ASBO. This study reviews patient outcomes after protocol implementation.

METHODS

We conducted a retrospective review of all patients with ASBO from January 1997 to December 2007. Data were categorized by admission date and use of GG. The outcomes reviewed were protocol uptake, median LOS in hospital and operative rate. Results were analyzed using the Mann-Whitney U test and the 2-tailed Fisher exact test.

RESULTS

There were 710 patients with ASBO overall. Sixteen of 376 (4.3%) patients received GG before institution of the protocol (period 1), whereas 195 of 334 (58.4%) received GG thereafter (period 2). In period 2, use of GG was limited to between 58% and 69% of all potentially eligible patients per year. Fifty-seven of 710 (8%) patients required surgery. In period 1, there were no significant differences in median LOS in hospital (p=0.29) and operative rate (p=0.65) between patients who received GG and those who were managed without GG. In period 2, patients receiving GG had a greater median LOS in hospital (3 [range 2-5] v. 2 [range 1-5] d, p=0.048) but significantly lower operative rates (5.1% v. 12.9%, p=0.018). Overall, the median LOS decreased over time (period 1: 4 [2-7] d v. period 2: 2 [1-5] d, p=0.010). The operative rate did not vary substantially between periods (7.7% v. 8.4%, p=0.42).

CONCLUSION

The introduction of a protocol has increased the proportion of eligible patients receiving GG. However, protocol nonadherence and factors other than GG usage have influenced LOS in hospital and operative rates. Demonstrated benefits from previously published clinical trials have thus not been replicated within our setting.

Hyperosmolar Water-Soluble Contrast Medium in the Management of Adhesive Small-Intestine Obstruction

This prospective study investigated the value of the hyperosmolar water-soluble contrast medium Urografin® in choosing which patients with small-intestine obstruction, caused by post-operative adhesions, to treat conservatively. Thirty-seven patients with adhesive intestinal obstruction received Urografin® via a nasogastric tube. Direct abdominal radiographs were taken after 2, 4 and 8 h. Twenty-four patients (64.9%) had Urografin® in the right colon within 8 h and were considered to have partial obstruction. These patients commenced oral feeding even though abdominal radiographs revealed gas–fluid levels. In the remaining 13 patients (35.1%), Urografin® was not observed in the right colon within 8 h: three of the 13 patients (23.1%) were successfully treated conservatively; 10 of the 13 patients (76.9%) developed toxic signs and underwent surgery, with obstruction resulting from adhesive bands being confirmed at operation. Conservative treatment can be recommended for patients in whom contrast medium is observed in the right colon within 8 h following administration, regardless of the presence of obstruction signs. Absence of contrast medium in the right colon within 8 h cannot, however, be considered an indication for surgery.

Reoperation for small bowel obstruction--how critical is the timing?

The timing of reoperation for small bowel obstruction is a topic of significant debate. Any patient with evidence of strangulation should undergo urgent surgical intervention. However, predicting strangulation can be difficult. Because of this, previous authors have recommended everything from emergency operation for all patients presenting with small bowel obstruction to periods of observation that extend up to 14 days. Over the past century, the primary etiology of small bowel obstruction has shifted from hernias to postoperative adhesive disease, leading to a shift in the management paradigm. To manage small bowel obstruction successfully today, the clinician must distinguish the patient requiring urgent operation from those who benefit from nonoperative management. Furthermore, the clinician must be able to determine the appropriate length of time for conservative management. In this article we review the significant body of literature on this topic including the diagnostic workup and timing of potential operative intervention in the patient with small bowel obstruction.

Systematic review and meta-analysis of the diagnostic and therapeutic role of water-soluble contrast agent in adhesive small bowel obstruction

BACKGROUND

This meta-analysis assessed the diagnostic and therapeutic role of water-soluble contrast agent (WSCA) in adhesive small bowel obstruction (SBO).

METHODS

PubMed, Embase and Cochrane databases were searched systematically. The primary outcome in the diagnostic role of WSCA was its ability to predict the need for surgery. In the therapeutic role, the following were evaluated: resolution of SBO without surgery, time from admission to resolution, duration of hospital stay, complications and mortality. To assess the diagnostic role of WSCA, pooled estimates of sensitivity, specificity, positive and negative predictive values, and likelihood ratios were derived. For the therapeutic role of WSCA, weighted odds ratio (OR) and weighted mean difference (WMD) were obtained.

RESULTS

Fourteen prospective studies were included. The appearance of contrast in the colon within 4-24 h after administration had a sensitivity of 96 per cent and specificity of 98 per cent in predicting resolution of SBO. WSCA administration was effective in reducing the need for surgery (OR 0.62; P = 0.007) and shortening hospital stay (WMD -1.87 days; P < 0.001) compared with conventional treatment.

CONCLUSION

Water-soluble contrast was effective in predicting the need for surgery in patients with adhesive SBO. In addition, it reduced the need for operation and shortened hospital stay.

Improving the management of acute adhesive small bowel obstruction with CT-scan and water-soluble contrast medium: a prospective study

PURPOSE

Adhesive small bowel obstruction is usually managed nonoperatively, but there is still debate over the optimal duration of nonoperative management and the factors that predict failure of medical treatment. The aim of this study was to evaluate an algorithm using CT-scans and Gastrografin in the management of small bowel obstruction.

METHODS

In a prospective study, each patient admitted for small bowel obstruction underwent a physical examination, a plain film, and a CT-scan evaluation. Patients underwent emergency surgical exploration when bowel ischemia was suspected. Other patients received oral Gastrografin, and a second plain abdominal radiograph was done after 12 hours. In patients with clinical improvement, the nasogastric tube was removed and an immediate liquid diet was resumed. Other patients were referred for surgery.

RESULTS

In total, 118 patients with 123 episodes of small bowel obstruction were included. Thirty-six (29%) required immediate surgery because they presented clinical characteristics of bowel ischemia (36/36; 100%) or a defect in vascularization of the small bowel on CT-scan (5/36; 14%). The 87 remaining patients were managed nonoperatively, of which 28 deteriorated and were referred for surgery. The 59 other patients showed clinical improvement.

CONCLUSION

This study demonstrated the diagnostic role of Gastrografin(R) in discriminating between partial and complete small bowel obstruction. CT-scans were disappointing in their ability to predict the necessity of emergent laparotomies. We therefore recommend the use of Gastrografin(R) in adhesive small bowel obstruction patients who do not have clinical evidence of bowel ischemia. CT-scans should not be routinely performed in the decision-making process except when clinical history, physical examination, and plain film are not conclusive for small bowel obstruction diagnosis.

Water-soluble contrast medium (gastrografin) value in adhesive small intestine obstruction (ASIO): a prospective, randomized, controlled, clinical trial

BACKGROUND

Patients with adhesive small intestine obstruction (ASIO) are difficult to evaluate and to manage and their treatment is still controversial. The diagnostic and therapeutic role of water-soluble contrast medium (Gastrografin) in ASIO is still debated. This study was designed to determine the therapeutic role of Gastrografin in patients with ASIO.

METHODS

The study was a multicenter, prospective, randomized, controlled investigation. The primary end points were the evaluation of the operative rate reduction and shortening the hospital stay after the use of Gastrografin. A total of 76 patients were randomized into two groups: the control group received traditional treatment (TT), whereas the study group (GG) received in addition a Gastrografin meal and follow-through study immediately. Patients with Gastrografin in the colon within 36 hours were considered to be partially obstructed and submitted to nonoperative management. If after 36 hours, the Gastrografin had not entered the colon, the subjects were submitted to laparotomy.

RESULTS

No significant differences were found in age, sex, intravenous administration of prokinetics, incidence and characteristics of the previous procedures in surgical history of the patients, previous episodes of ASIO and surgery for adhesiolysis, or duration of symptoms before admission. In the GG group obstruction resolved subsequently in 31 of 38 cases (81.5%) after a mean time of 6.4 hours. The remaining seven patients were submitted to surgery, and one of them needed bowel resection for strangulation. In the control group, 21 patients were not submitted to surgery (55%), whereas 17 showed persistent untreatable obstruction and required laparotomy: 2 of them underwent bowel resection for strangulation. The difference in the operative rate between the two treatment groups reached statistical significance (p = 0.013). The time from the hospital admission for obstruction to resolution of symptoms was significantly lower in the GG group (6.4 vs. 43 hours; p < 0.01). The length of hospital stay revealed a significant reduction in the GG group (4.7 vs. 7.8 days; p < 0.05). This reduction was more evident in the subset of patients who did not require surgery (3 vs. 5.1 days; p < 0.01). No GG-related complications or significant differences in major complications and the relapse rate were found (relapse rate, 34.2% after a mean time to relapse of 6.3 months in the GG group vs. 42.1% after 7.6 months in the TT; p = not significant).

CONCLUSIONS

Data showed that the use of Gastrografin in ASIO is safe and reduces the operative rate and the time to resolution of obstruction, as well as the hospital stay.

Comparison of Urografin Versus Standard Therapy in Postoperative Small Bowel Obstruction

Water-soluble contrast media (Urografin) cause redistribution of intravascular and extracellular fluid into intestinal lumen due to their hyperosmolarity. As a consequence, these media decrease intestinal wall edema and act as a direct stimulant to intestinal peristalsis. In this prospective study, we aimed to examine objectively the therapeutic role and ability of Urografin in patients with postoperative small bowel obstruction for whom failed to respond to conservative treatment. Three hundred and seventeen patients with postoperative small bowel obstruction due to intraperitoneal adhesions were included prospectively in this study. In the Urografin group, 40 mL Urografin diluted in 40 mL distilled water was administered through the nasogastric tube. No contrast media were administered in the control group, but the patients were decompressed via a nasogastric tube continuously. The number of obstruction episode in 317 patients was 338. In total, 199 patients were in the Urografin group, and 118 patients were in the control group. In the Urografin group, 178 (89.4%) patients responded successfully to the treatment, but 21 (11.6%) patients underwent surgical operation. Intensive intraabdominal adhesions and obstructing fibrous bands were observed and repaired in 15 (71.4%) patients at the operation, while 6 patients underwent segmental small intestine resection in control group, conventional management was successful in only 89 (75.4%) patients, and the remaining 29 (24.6%) patients underwent surgical intervention. In conclusion, it was suggested that in patients with intestinal obstruction due to postoperative intra-abdominal adhesion, water-soluble contrast media such as Urografin may be safely administered via a nasogastric tube or oral route and may decrease the need for surgical operation; furthermore, they may help the physician to operate the patients who needs surgery as early as possible.

Clinical impacts of oral gastrografin follow-through in adhesive small bowel obstruction (SBO)

BACKGROUND

Many studies have shown that gastrografin can be used for diagnosis of adhesive small bowel obstruction (ASBO) and for assessing the need for surgical intervention. However, several studies have reported conflicting results. Therefore, the aim of this study is to assess the diagnostic and therapeutic effect of gastrografin in ASBO.

PATIENTS AND METHODS

Altogether, 110 patients with ASBO were randomized into control and gastrografin groups. In the gastrografin group, 100 mL of the dye was administered through a nasogastric tube. Obstruction was considered complete if the contrast failed to reach the colon on the 24-h film. Patients with gastrografin in the colon within 24 h after dye administration were considered as partially obstructed, and were submitted to nonoperative treatment. The patients were operated on if they developed signs of strangulation or failed to improve within 48 h.

RESULTS

The overall operative rate was 14.5% in gastrografin group versus 34.5% in control group, P=0.04. The time from admission to resolution of symptoms was significantly lower in gastrografin group (19.5 versus 42.6 h, P=0.001), and the length of hospital stay was shorter in gastrografin group (3.8 versus 6.9 d 0.002), and in nonoperative patients (3.1 versus 5.1 days). Sensitivity, specificity, positive predictive value, and negative predictive value for gastrografin follow-through as an indicator for operative treatment of ASBO were 87.5%, 100%, 100 % , and 97.9%, respectively.

CONCLUSIONS

Oral gastrografin helps in the management of ASBO. Oral gastrografin is safe and reduces the operative rate and time of resolution as well as hospital stay.

Oral water soluble contrast for the management of adhesive small bowel obstruction

BACKGROUND

Adhesions are the leading cause of small bowel obstruction. Gastrografin transit time may allow for the selection of appropriate patients for non-operative management. Some studies have shown when the contrast does not reach the colon after a designated time it indicates complete intestinal obstruction that is unlikely to resolve with conservative treatment. When the contrast does reach the large bowel, it indicates partial obstruction and patients are likely to respond to conservative treatment. Other studies have suggested that the administration of water-soluble contrast is therapeutic in resolving the obstruction.

OBJECTIVES

To determine the reliability of water-soluble contrast media and serial abdominal radiographs in predicting the success of conservative treatment in patients admitted with adhesive small bowel obstruction.Furthermore, to determine the efficacy and safety of water-soluble contrast media in reducing the need for surgical intervention and reducing hospital stay in adhesive small bowel obstruction.

SEARCH STRATEGY

The search was conducted using MESH terms: ''Intestinal obstruction'', ''water-soluble contrast'', "Adhesions" and "Gastrografin". The later combined with the Cochrane Collaboration highly sensitive search strategy for identifying randomised controlled trials and controlled clinical trials.

SELECTION CRITERIA

1. Prospective studies were included to evaluate the diagnostic potential of water-soluble contrast in adhesive small bowel obstruction.2. Randomised clinical trials were selected to evaluate the therapeutic role.

DATA COLLECTION AND ANALYSIS

1. Studies that addressed the diagnostic role of water-soluble contrast were critically appraised and data presented as sensitivities, specificities and positive and negative likelihood ratios. Results were pooled and summary ROC curve was constructed.2. A meta-analysis of the data from therapeutic studies was performed using the Mantel -Henszel test using both the fixed effect and random effect models.

MAIN RESULTS

The appearance of water-soluble contrast in the colon on an abdominal X ray within 24 hours of its administration predicts resolution of an adhesive small bowel obstruction with a pooled sensitivity of 0.97, specificity of 0.96. The area under the curve of the summary ROC curve is 0.98. Six randomised studies dealing with the therapeutic role of gastrografin were included in the review, water-soluble contrast did not reduce the need for surgical intervention (OR 0.81, p = 0.3). Meta-analysis of four of the included studies showed that water-soluble contrast did reduce hospital stay compared with placebo (WMD= - 1.83) P<0.001.

AUTHORS' CONCLUSIONS

Published literature strongly supports the use of water-soluble contrast as a predictive test for non-operative resolution of adhesive small bowel obstruction. Although Gastrografin does not cause resolution of small bowel obstruction there is strong evidence that it reduces hospital stay in those not requiring surgery.

Meta-analysis of oral water-soluble contrast agent in the management of adhesive small bowel obstruction

BACKGROUND

Adhesions are the leading cause of small bowel obstruction. Identification of patients who require surgery is difficult. This review analyses the role of Gastrografin as a diagnostic and therapeutic agent in the management of adhesive small bowel obstruction.

METHODS

A systematic search of Medline, Embase and Cochrane databases was performed to identify studies of the use of Gastrografin in adhesive small bowel obstruction. Studies that addressed the diagnostic role of water-soluble contrast agent were appraised, and data presented as sensitivity, specificity, and positive and negative likelihood ratios. Results were pooled and a summary receiver-operator characteristic (ROC) curve was constructed. A meta-analysis of the data from six therapeutic studies was performed using the Mantel-Haenszel test and both fixed- and random-effect models.

RESULTS

The appearance of water-soluble contrast agent in the colon on an abdominal radiograph within 24 h of its administration predicted resolution of obstruction with a pooled sensitivity of 97 per cent and specificity of 96 per cent. The area under the summary ROC curve was 0.98. Water-soluble contrast agent did not reduce the need for surgical intervention (odds ratio 0.81, P = 0.300), but it did reduce the length of hospital stay for patients who did not require surgery compared with placebo (weighted mean difference--1.84 days; P < 0.001).

CONCLUSION

Published data strongly support the use of water-soluble contrast medium as a predictive test for non-operative resolution of adhesive small bowel obstruction. Although Gastrografin does not reduce the need for operation, it appears to shorten the hospital stay for those who do not require surgery.

[Emergency radiology of bowel obstruction]

Clinical radiology is a key to the management of bowel obstruction. Plain abdominal radiographs combined with history, clinical exam, and laboratory findings are essential for further individualized strategies. If the cause of obstruction is obvious after plain films and there is a need for emergent surgery, no further imaging is required. In all other cases, multislice CT with at least intravenous and rectal contrast is the method of choice due to its broad diagnostic spectrum. If CT is not available, contrast enema is recommended in suspected large bowel obstruction. Oral administration of water-soluble contrast agents has no significant value in the workup of bowel obstruction.

ACR Appropriateness Criteria® on Suspected Small-Bowel Obstruction

With no one generally accepted approach to evaluate patients with suspected small-bowel obstruction (SBO), standard CT has emerged as the preeminent imaging modality and should be considered in the initial evaluation of patients with suspected high-grade SBO. Playing less significant roles in the diagnosis of acute SBO are barium enemas and the small-bowel examination.

Value of Water-soluble Contrast (Meglumine Amidotrizoate) in the Diagnosis and Management of Small Bowel Obstruction

INTRODUCTION

The object of the present study was to determine the effectiveness of a water-soluble contrast follow-through study for differentiating complete from incomplete small bowel obstruction (SBO) and for predicting the need for surgery.

METHODS

This prospective study was conducted at Riyadh Medical Complex, Saudi Arabia and spanned 2 years. All adult patients admitted with SBO were included, except those with obstructed hernias, peritonitis, or postabdominal irradiation. The initial resuscitation meglumine amidotrizoate (Gastrografin) follow-though was performed and was considered positive for complete obstruction if the contrast failed to reach the colon as shown on the 24-hour film. Patients were operated on only if they developed signs of strangulation or failed to improve within 48 hours.

RESULTS

Our study group consisted of 73 patients, 48 (65.7%) of whom were male. The mean age was 35.70+/-12.65 years. In 60 (82.2%) patients, contrast reached the ascending colon within 24 hours, giving a definitive diagnosis of incomplete obstruction; among these 60 cases, 49 (81.7%) resolved on conservative management. The other 13 (17.8%) patients were diagnosed as having a complete obstruction; 4 (30.8%) of them were treated conservatively, and 9 (69.2%) underwent surgery. Therefore the sensitivity, specificity, positive predictive value, and negative predictive value for meglumine amidotrizoate follow-through as an indicator for operative treatment of SBO were 45.0, 92.5, 81.7, and 69.2, respectively. The P value using Fisher's exact test was 0.0006.

CONCLUSIONS

We can confidently diagnose complete and incomplete SBO and differentiate one from the other. This accurate diagnosis indicates a high chance of success with conservative management for incomplete obstruction but does not always correlate with the need for surgical intervention.

Randomized controlled trial of Gastrografin in adhesive small bowel obstruction

BACKGROUND

Several previous studies have shown that Gastrografin can be utilized to triage patients with adhesive small bowel obstruction (ASBO) to an operative or a non-operative course. Previous studies assessing the therapeutic effect of Gastrografin have been confounded by post-administration radiology alerting the physician to the treatment group of the patient. Therefore the aim of the present paper was to test the hypothesis that Gastrografin hastens the non-operative resolution of (ASBO).

METHODS

Patients, diagnosed with ASBO on clinical and radiological grounds, were randomized to receive Gastrografin or placebo in a double-blinded fashion. Patients did not undergo further radiological investigation. If the patient required subsequent radiological intervention or surgical intervention they were excluded from the study. End-points were passage of time to resolution of ASBO (flatus and bowel motion), length of hospital stay and complications.

RESULTS

Forty-five patients with ASBO were randomized to receive either Gastrografin or placebo. Two patients were excluded due to protocol violations. Four patients in each group required surgery. Eighteen of the remaining patients received Gastrografin and 17 received placebo. Patients who received Gastrografin had complete resolution of their ASBO significantly earlier than placebo patients (12 vs 21 h, P = 0.009) and this translated into a median of a 1-day saving in time in hospital (3 vs 4 days, P = 0.03).

CONCLUSIONS

Gastrografin accelerates resolution of ASBO by a specific therapeutic effect.

Progressive increase of bowel wall thickness is a reliable indicator for surgery in patients with adhesive small bowel obstruction

PURPOSE

The aim of this study was to determine whether progressive increase of bowel wall thickness during nonoperative treatment is a reliable indicator for surgery in patients with adhesive small bowel obstruction.

METHODS

The study consisted of a prospective case series of 121 patients with adhesive small bowel obstruction who underwent an abdominal ultrasonographic examination. The results of ultrasonographic examinations were classified into two groups according to the presence (Group I) or absence (Group II) of bowel wall thickening. Bowel wall thickening was recognized as a visible small bowel wall > or =3 mm in width as seen by ultrasonographic examination. The findings of subsequent ultrasonographic examinations taken 24 hours later were compared with those taken at admission. Surgery was determined based on the presence of any toxic signs or the failure of nonoperative treatment. The number of patients who had successful nonoperative treatment, the number of patients who underwent surgeries, and the number of complications in each group were calculated to correlate with the ultrasonographic findings.

RESULTS

There are 49 and 72 patients in Groups I and II, respectively. The number of patients who had successful nonoperative treatment and number of patients who underwent surgeries in Group I are 40 (81.6 percent) and 9 (18.4 percent) and in Group II the numbers are 68 (94.4 percent) and four (5.6 percent), respectively (P = 0.036). All 12 (100 percent) patients with progressive increase of bowel wall thickness underwent surgery. Progressive increase of bowel wall thickness as an indicator for surgery has a sensitivity of 92.3 percent (95 percent confidence interval, 62.1-99.6 percent) and a specificity of 100 percent (95 percent confidence interval, 95.7-100 percent).

CONCLUSIONS

Patients with initial bowel wall thickening have a higher incidence of surgery, and progressive increase of bowel wall thickness that appears 24 hours later is a reliable indicator for surgery in patients with adhesive small bowel obstruction.

Telebrix Gastro in the management of adhesive small bowel obstruction

BACKGROUND

This study aimed to determine whether an abdominal radiograph 8 hours after ingesting oral Telebrix Gastro is a reliable marker for non-operative management in patients with adhesive small bowel obstruction.

METHODS

During a 5-year period (January 1, 1995, through December 31, 2000), 97 patients were admitted for small bowel occlusion due to adhesion with no indication for immediate surgery. All received 100 mL of Telebrix Gastro via gastric tube for small bowel obstruction due to adhesion. If the contrast reached the colon within 8 hours on plain abdominal radiograph, the test was considered to be negative.

RESULTS

126 cases of small bowel occlusions were analyzed due to recurring episodes for 11 patients. The test was negative in 113 cases (89.7%), and in this group, only two patients underwent surgery, the remaining being managed non-operatively. The 13 cases (10.3%) with a positive test for occlusion underwent surgery. The sensitivity, specificity and accuracy of the finding of contrast media reaching the colon as an indicator for conservative treatment were 98%, 100%, and 98%, respectively.

CONCLUSIONS

A water-soluble contrast study can be of significant help in the clinical management of patients suspected of having small bowel obstruction.

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.

Oral water soluble contrast for the management of adhesive small bowel obstruction

BACKGROUND

Adhesions are the leading cause of small bowel obstruction. Most adhesive small bowel obstructions resolve following conservative treatment but there is no consensus as to when conservative treatment should be considered unsuccessful and the patient should undergo surgery. Studies have shown that failure of an oral water-soluble contrast to reach the colon after a designated time indicates complete intestinal obstruction that is unlikely to resolve with conservative treatment. Other studies have suggested that the administration of water-soluble contrast is therapeutic in resolving the obstruction.

OBJECTIVES

The aims of this review are:1. To determine the reliability of water-soluble contrast media and serial abdominal radiographs in predicting the success of conservative treatment in patients admitted with adhesive small bowel obstruction.2. To determine the efficacy and safety of water-soluble contrast media in reducing the need for surgical intervention and reducing hospital stay in adhesive small bowel obstruction.

SEARCH STRATEGY

The search was conducted using MeSH terms: ''Intestinal obstruction'', ''water-soluble contrast'', "Adhesions" and "Gastrografin", and combined with the Cochrane Collaboration highly sensitive search strategy for identifying randomised controlled trials and controlled clinical trials.

SELECTION CRITERIA

1. Prospective studies (to evaluate the diagnostic potential of water-soluble contrast in adhesive small bowel obstruction);2. Randomised clinical trials (to evaluate the therapeutic role).

DATA COLLECTION AND ANALYSIS

1. Studies addressing the diagnostic role of water-soluble contrast were critically appraised and data presented as sensitivities, specificities and positive and negative likelihood ratios. Results were pooled and summary receiver operating characteristic (ROC) curve was constructed. 2. A meta-analysis of the data from therapeutic studies was performed using the Mantel -Haenszel test using both the fixed effect and random effects model.

MAIN RESULTS

The appearance of water-soluble contrast in the caecum on an abdominal radiograph within 24 hours of its administration predicts resolution of an adhesive small bowel obstruction with a pooled sensitivity of 0.96, specificity of 0.96. The area under the curve of the summary ROC was 0.98. Four randomised studies dealing with the therapeutic role of Gastrografin were included in the review, water-soluble contrast did not reduce the need for surgical intervention (odds ratio 1.29, P = 0.36). Meta-analysis of two studies showed that water-soluble contrast reduced hospital stay compared with placebo (weighted mean difference = - 2.58) P = 0.004.

AUTHORS' CONCLUSIONS

Published literature strongly supports the use of water-soluble contrast as a predictive test for non-operative resolution of adhesive small bowel obstruction. Although Gastrografin does not cause resolution of small bowel obstruction, it does appear to reduce hospital stay.

Aggressive pharmacological treatment for reversing malignant bowel obstruction

Early and intensive pharmacological treatment not only may reduce gastrointestinal symptoms but also reverse malignant bowel obstruction. Fifteen consecutive advanced cancer patients with inoperable bowel obstruction received a combination of drugs including metoclopramide, octreotide, dexamethasone and an initial bolus of amidotrizoato. Recovery of intestinal transit was reported within 1-5 days in fourteen patients, who continued this treatment without presenting symptoms of bowel obstruction until death. This case series establishes that the combination of propulsive and antisecretive agents can act synergistically to allow a fast recovery of bowel transit without inducing unpleasant colic. It suggests that the most important mechanism in these circumstances is functional and can be reversible, if an aggressive treatment is initiated early before fecal impaction and edema render bowel obstruction irreversible.

Role of Gastrografin in assigning patients to a non‐operative course in adhesive small bowel obstruction

BACKGROUND

Adhesive small bowel obstruction (SBO) is a common surgical emergency. Water soluble contrast agents have been used to identify patients who might be treated non-operatively rather than operatively. The present study was designed to audit the introduction of such use of Gastrografin contrast into clinical practice.

METHOD

Patients presenting acutely to hospital with clinically suspected and radiologically proven SBO were entered in the study. As soon as practicable, 100 mL of undiluted Gastrografin was given either orally or by the nasogastric tube (which was then spigotted). After 4 h, a plain supine abdominal X-ray (AXR) was taken. If the contrast was seen in the large bowel, and there had been no deterioration in the patient's condition, then non-operative treatment was continued. If the contrast remained in the small bowel, a clinical judgement was made as to whether to proceed with operative intervention. A group of historical controls were obtained by a retrospective review of the hospital medical records through data obtained from the Department of General Surgery Audit System.

RESULTS

Twenty-five patients were entered into the study. In 20 of these patients the contrast was seen to arrive in the large bowel at 4 h. All of these patients completed a non-operative course to full recovery. In another two patients a successful decision was made to pursue a non-operative management strategy. These 22 patients had a mean hospital stay of 3.9 days. Eighty historical controls had successfully completed a non-operative course for SBO. They had a mean hospital stay of 5.6 days. This was significantly longer than that of the Gastrografin group (P < 0.016, t-test).

CONCLUSION

This paper has demonstrated that undiluted Gastrografin may be safely used to assign patients to a non-operative management plan and this results in a decreased hospital stay.

Small bowel obstruction--the water-soluble follow-through revisited

AIMS

The aim of the present study to examine the use of a modified water-soluble follow-through in the diagnosis and management of small bowel obstruction (SBO).

MATERIALS AND METHODS

Sixty-two patients were recruited to the study: 33 into the control group and 29 into the study group. A modified small bowel follow-through (SBFT) was performed in the study group patients. The control group was managed conventionally. Assessment was made by questionnaire documenting initial surgical diagnosis and likelihood of operative intervention, final diagnosis and surgical outcome (operative versus non-operative).

RESULTS

SBFT changed the diagnosis in 12/24 of the study group (p<0.01). In the study group 8/24 proceeded to surgery whereas 19/33 underwent laparotomy in the control group, representing a relative risk reduction of 52%, but this was not statistically significant (0.10>p>0.05, chi-squared test).

CONCLUSION

SBFT remains a valid and useful tool in surgical management of SBO. In particular it aids diagnostic confidence in planning surgical intervention, particularly in uncomplicated patients.

Current concepts in imaging of small bowel obstruction

The diagnosis and treatment of small bowel obstruction continue to evolve. The imaging approach in the work-up of patients with known or suspected small bowel obstruction and the timing of surgical intervention in this disease have undergone considerable changes over the past two decades. This article examines the current concepts related to the use of imaging technology in the diagnosis and management of patients with small bowel obstruction. The meaning of frequently used but poorly defined terms in describing intestinal obstruction is clarified and illustrated.

Small Bowel Obstruction

The optimal treatment of patients with small bowel obstruction should be predicated upon answering the following diagnostic questions in each patient: 1) does the patient have mechanical bowel obstruction or an ileus?, 2) could the patient have colonic obstruction or a cause of obstruction other than adhesions (eg, hernia, cancer, Crohn's disease)?, 3) is the obstruction partial or complete?, and 4) is strangulation present, and hence immediate operation necessary, or is a period of observation appropriate? The most efficient way to answer these questions in many patients is by performing a careful history and physical examination, laboratory tests, and CT scanning. Surgical intervention should occur within 48 hours of admission in the vast majority of patients with complete small bowel obstruction due to adhesions. The chance for durable endoscopic treatment of any patient with SBO, in our opinion, is remote.

Acute intestinal obstruction: diagnosis and management

In acute intestinal obstruction, the clinician must distinguish between acute small bowel obstruction (ASBO) and acute colonic obstruction (ACO). In cases of ASBO, management depends on whether the patient has had previous abdominal surgery. Most cases of ACO require surgery, although mechanical causes must be distinguished from pseudo-obstruction for different management techniques.

Intravenous Interleukin-6 Levels Predict Need for Laparotomy in Patients with Bowel Obstruction

Interleukin-6 (IL-6) has been identified as a marker of ischemia. However, its association with bowel obstruction has not been studied. Fifty-seven patients diagnosed with bowel obstruction were evaluated in a prospective blinded study and managed either medically (n = 29) or surgically (n = 28) per decision of attending surgeon. Serum IL-6 levels were obtained at the time of diagnosis and serially during hospitalization. Mean IL-6 levels at the time of diagnosis were significantly higher in patients who required operation compared with medically treated patients (63.9 vs 19.6 pg/mL respectively; P = 0.027). Levels returned to those seen in medically treated patients 3 days after operation. There was no difference in temperature, white blood cell count, or lactic acid levels. Five patients required resection for ischemic bowel. Patients with ischemic bowel had significantly higher initial mean IL-6 (146.6 vs 45.9 pg/mL; P = 0.034) and lactic acid (23.6 vs 11.8 mg/dL; P = 0.035) at time of diagnosis compared with surgically treated patients without bowel ischemia. No difference in white blood cell count was seen. IL-6 was a sensitive predictor of patients with bowel obstruction requiring operation and for presence of ischemic bowel. IL-6 screening may allow for earlier and more selective operation potentially decreasing morbidity and mortality.

Contrast radiography in small intestinal obstruction, a valuable diagnostic tool?

OBJECTIVE

To investigate the diagnostic and therapeutic potential of plain abdominal radiographs and contrast radiography in patients with suspected small intestinal obstruction.

DESIGN

Retrospective study.

SETTING

General hospital, Sweden.

MATERIAL

2357 sets of plain abdominal radiographic casenotes.

MAIN OUTCOME MEASURES

Analysis of plain abdominal radiographs for small intestinal obstruction. Establishment of the time that subsequent contrast radiography medium took to reach the caecum, and its success rate.

RESULTS

Of the 2357 plain abdominal films 1599 (68%) did not show small intestinal obstruction, 425 (18%) showed intermediate obstruction, and 333 (14%) showed small intestinal obstruction. The water-soluble contrast medium reached the colon in 394/591 (67%) of the cases with intermediate or complete small intestinal obstruction. Although the contrast medium passed to the colon there was remaining abnormality with dilated small intestine in 71/212 (33%) of the cases with intermediate obstruction and in 95/143 (66%) of the small intestinal obstruction group. The time for the contrast medium to reach the colon was 3.4 hours in the normal group, 5.5 hours in the intermediate group and 8.9 hours in the obstruction group.

CONCLUSION

The plain abdominal radiographs seem to predict the success of follow-through examinations. Contrast radiography is safe and may have a therapeutic potential in small intestinal obstruction.

The Use of Water-Soluble Contrast in Evaluating Clinically Equivocal Small Bowel Obstructions

This study seeks to determine whether a 6-hour abdominal radiograph after oral Gastrografin is a reliable indicator for nonoperative treatment in patients with a clinically equivocal small bowel obstruction. We collected retrospective data from medical records. Patients who received a Gastrografin transit time (GGTT) study between January 1995 and September 1998 were included in the study. Patients who did not appear to be obvious operative candidates, but had signs of intestinal obstruction, underwent a GGTT study. Serial plain abdominal radiographs were taken. If the contrast was in the colon within 6 hours, then the result was negative. A total of 418 GGTT studies were reviewed. Contrast reached the colon within 6 hours in 283 (68%) patients, and 247 (88%) of these patients were managed nonoperatively. The positive predictive value, negative predictive value, sensitivity, and specificity of Gastrografin reaching the colon within 6 hours were 48, 87, 64, and 78, respectively. False negatives included high-grade partial obstructions that ultimately required surgery. Recent operation preceded the GGTT in 128 (31%) cases. Of these 128 patients, only 17 (14%) received an operation. Although the decision to operate or not should never be based on a GGTT study alone, GGTT studies are of significant help in the clinical management of patients suspected to have a small bowel obstruction. GGTT allows for the judicious selection of the appropriate patient for nonoperative management. GGTT studies are cost effective, safe, and clinically useful when attempting to treat patients conservatively.

Intestinal obstruction

Intestinal obstruction, a disorder that afflicts both children and adults, is associated with significant morbidity. Early recognition and appropriate management can prevent life-threatening complications; however, considerable controversies exist regarding the ideal method of diagnosis and treatment. This article provides a comprehensive overview of risk factors for small and large bowel obstruction. The pathophysiologic process is related to the clinical findings. A summary of diagnostic methods with an evaluation of their relative merit is presented. Preventive, and medical, surgical, and palliative therapies are described, with an emphasis on the actions that an advanced practice nurse can implement.

The role of computed tomography with contrast and small bowel follow-through in management of small bowel obstruction

BACKGROUND

In a significant percentage of patients, radiologic evaluation other than plain abdominal films are required to confirm or exclude the presence of small bowel obstruction.

METHODS

Over a 1-year period, 55 patients had both computed tomography and small bowel follow-through studies. Patients were classified as having (1) paralytic ileus, (2) low-grade obstruction, (3) high-grade obstruction, or (4) complete mechanical obstruction. The gold standard for diagnosis was celiotomy in 42 patients and clinical follow-up in 13 patients.

RESULTS

Thirty-six out of 42 patients had proven intestinal obstruction at the time of celiotomy. Computed tomography identified 32 out of the 36 high-grade and complete mechanical obstructions. Computed tomography was superior to small bowel follow-through in identifying masses, malignancies, and features of strangulation. Small bowel follow-through correctly identified "insignificant obstructions" when contrast reached the cecum within 4 hours in 18 of 19 patients.

CONCLUSIONS

In patients with equivocal findings of small bowel obstruction, computed tomography should be used initially and then small bowel follow-through if computed tomography is not diagnostic. Computed tomography was superior in this study for detecting the cause of the intestinal obstruction and presence of strangulation.