Small-bowel obstruction: optimizing radiologic investigation and nonsurgical management

Small bowel obstruction and intestinal ischemia: emphasizing the role of MDCT in the management decision process

The objective of this article is to assess the computed tomography (CT) findings of small bowel obstruction (SBO) complicated by ischemia. SBO is a frequent clinical entity characterized by high morbidity and mortality. The radiologic aim is not just to diagnose the obstruction itself but to rule out the presence of complications related to SBO. This is crucial for differentiating which patients can be safely treated non-operatively from the ones who may need an urgent surgical approach. The main complication of SBO is intestinal ischemia. In the emergency setting, CT imaging is the modality of choice for SBO because of its ability to assess the bowel wall, the supporting mesentery and peritoneal cavity all in one. On the other hand, the radiologist who documents an intestinal ischemia should think about SBO as possible cause. In this case, the main finding which helps the radiologist in the identification of SBO is the presence of multiple and packed valvulae conniventes in the dilated bowel wall and the "transition zone" that indicates the passage between compressed and decompressed small bowel, otherwise the localization of the obstruction cause. Once the site of obstruction has been recognized, the other issue is to assess the cause of obstruction, considering that the most common cause of SBO remains "unidentified" and related to intra-abdominal adhesions. After that, the following most important point is to rule out the presence of an ischemic bowel and mesenteric changes associated to SBO. CT signs of bowel ischemia include reduced or increased bowel wall enhancement, mesenteric edema or engorgement, fluid or free air in the peritoneal cavity. This condition usually leads to an urgent laparotomy and, in some cases, to a surgical resection.

Gastrointestinal Manifestations of Immunodeficiency: Imaging Spectrum

There is a wide spectrum of hereditary and acquired immunodeficiency disorders that are characterized by specific abnormalities involving a plethora of humoral, cellular, and phagocytic immunologic pathways. These include distinctive primary immunodeficiency syndromes due to characteristic genetic defects and secondary immunodeficiency syndromes, such as AIDS from HIV infection and therapy-related immunosuppression in patients with cancers or a solid organ or stem cell transplant. The gut mucosa and gut-associated lymphoid tissue (the largest lymphoid organ in the body), along with diverse commensal microbiota, play complex and critical roles in development and modulation of the immune system. Thus, myriad gastrointestinal (GI) symptoms are common in immunocompromised patients and may be due to inflammatory conditions (graft versus host disease, neutropenic enterocolitis, or HIV-related proctocolitis), opportunistic infections (viral, bacterial, fungal, or protozoal), or malignancies (Kaposi sarcoma, lymphoma, posttransplant lymphoproliferative disorder, or anal cancer). GI tract involvement in immunodeficient patients contributes to significant morbidity and mortality. Along with endoscopy and histopathologic evaluation, imaging plays an integral role in detection, localization, characterization, and distinction of GI tract manifestations of various immunodeficiency syndromes and their complications. Select disorders demonstrate characteristic findings at fluoroscopy, CT, US, and MRI that permit timely and accurate diagnosis. While neutropenic enterocolitis affects the terminal ileum and right colon and occurs in patients receiving chemotherapy for hematologic malignancies, Kaposi sarcoma commonly manifests as bull's-eye lesions in the stomach and duodenum. Imaging is invaluable in treatment follow-up and long-term surveillance as well. Online supplemental material is available for this article. ^©RSNA, 2022.

Prospective evaluation of intestinal decompression in treatment of acute bowel obstruction from Crohn's disease

Background

Conservative therapy for Crohn’s disease (CD)-related acute bowel obstruction is essential to avoid emergent surgery. The present study aimed to evaluate the efficacy of using a long intestinal decompression tube (LT) in treatment of CD with acute intestinal obstruction.

Methods

This is a prospective observational study. Comparative analysis was performed in CD patients treated with LT (the LT group) and nasogastric tube (the GT group). The primary outcome was the avoidance of emergent surgery. Additionally, predictive factors for failure of decompression and subsequent surgery were investigated.

Results

There were 27 and 42 CD patients treated with LT and GT, respectively, in emergent situations. Twelve (44.4%) patients using LT were managed conservatively without laparotomy, while only nine (21.4%) patients in the GT group were spared from emergent surgery (P < 0.05). Both in surgery-free and in surgery patients, the time to alleviation of symptoms was significantly shorter in the LT groups than in the GT groups (both P < 0.01). C-reactive protein decrease after intubation and 48-hour drainage volume >500 mL were predictors of unavoidable surgery (both P < 0.05). The rate of temporary stoma and incidence of incision infection in the LT surgery group were significantly lower than those in the GT group (both P < 0.05). No significant differences were observed in the frequency of medical and surgical recurrences between the LT and GT groups (all P > 0.05).

Conclusions

Endoscopic placement of LT could improve the emergent status in CD patients with acute bowel obstruction. The drainage output and changes in C-reactive protein after intubation could serve as practical predictive indices for subsequent surgery. Compared to traditional GT decompression, LT decompression was associated with fewer short-term complications and did not appear to affect long-term recurrence.

Placement of a Long Intestinal Tube in Patients with Early Postoperative Small Bowel Obstruction under Fluoroscopic Guidance

OBJECTIVE

To investigate the placement of a long tube into the small intestine under fluoroscopic guidance and to evaluate its decompression effect on early postoperative small bowel obstruction (EPSBO).

METHODS

Fifty-four patients with EPSBO requiring decompression between April 2010 and July 2014 were enrolled in the study. Insertion of a long tube was guided by fluoroscopy. We first used the guide wire to pass the pylorus and then used the 10 Fr feeding tube as an exchangeable tube to put the superstiff wire into the duodenum. Finally the long tube could be passed over the guide wire through the pylorus into the intestine. The total procedure time, the radiation exposure time, and the incidence of complications were evaluated.

RESULTS

The long tubes passed into the jejunum on initial insertion for all patients, so the success rate of this technique was 100%. The long tube was inserted into ileum in 18 patients. The mean total procedure time was 34.4 ± 8.6 minutes, and the mean radiation exposure time 18.9 ± 6.8 minutes. A total of 47 patients (87%) experienced full recovery following long-tube decompression and without the need for surgical intervention.

CONCLUSIONS

Using the wire-exchange technique, it is easy to place a long tube into the small bowel under fluoroscopic guidance. This decompression method is safe and effective for management of EPSBO.

Review of small-bowel obstruction: the diagnosis and when to worry

This is a review of small-bowel obstruction written primarily for residents. The review focuses on radiography and computed tomography (CT) for diagnosing small-bowel obstruction and CT for determining complications. (©) RSNA, 2015.

Pretreatment of gastric outlet obstruction with pancrelipase: Report of a case

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Gastric outlet obstruction is characterized by the retention of gastric contents.

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A nasogastric tube alone may not adequately drain the obstructed stomach.

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Pancrelipase allows gastric contents to be removed in a short period of time.

Introduction

Gastric outlet obstruction is characterized by the retention of gastric contents. Removal of gastric contents is an important part of the treatment strategy. The use of a nasogastric tube alone can result in inadequate removal of gastric contents. We treated a patient with advanced gastric cancer and gastric outlet obstruction with pancrelipase to aid in the removal of gastric contents.

Presentation of case

The patient is an 81-year-old man with a Type 3 gastric cancer nearly circumferentially involving the antrum, resulting in gastric outlet obstruction. A nasogastric tube was placed for four days, but drainage of gastric contents was inadequate. Pancrelipase was then given orally for four days, and gastric contents were evacuated. The patient underwent distal gastrectomy with Roux-en-Y reconstruction and was discharged from the hospital on postoperative day 14.

Discussion

This report suggests that pancrelipase may be beneficial in the treatment of patients with gastric outlet obstruction.

Conclusion

Pancrelipase allowed gastric contents to be evacuated in a short period of time in a patient with gastric outlet obstruction.

Meaning of free intraperitoneal fluid in small-bowel obstruction: preliminary results using high-frequency microsonography in a rat model

OBJECTIVES

The aim of this study was to detect the onset, evolution, and meaning of extraluminal free fluid in a rat model of small-bowel obstruction using high-frequency microsonography.

METHODS

Small-bowel obstruction was surgically created in 8 rats divided into 2 groups of 4 rats each. All rats were examined by high-frequency microsonography to monitor the evolution of small-bowel obstruction and the abdominal sonographic findings. In group 2 rats, the obstruction was resolved 2 hours after surgery.

RESULTS

In all rats, free peritoneal fluid was detected just near the obstructed loop after 1 hour and in the hepatorenal recess after 2 hours. These features progressively increased in the following hours in group 1 rats. In group 2, the amount of free fluid decreased shortly after removing the obstruction.

CONCLUSIONS

Free fluid is an early finding in small-bowel obstruction, and the increase or decrease of its amount is correlated with the worsening or resolution of the obstruction.

Small bowel obstruction secondary to transport aircraft: coincidence or reality?

Small bowel obstructions (SBO) are a leading cause of admission to general surgery, posing the problem of the aetiology and treatment based on the diagnosis. More than 300 patients were admitted for SBO in 2011 in our institution. In our clinical practice, we have had to care for patients with SBO immediately after air travel, all of whom had an antecedent of abdominal surgery by laparotomy. The finding of episodes of acute SBO immediately following a commercial flight has never been reported in the literature. We report the cases of four patients for whom we offer several pathophysiological hypotheses, and we publish the first dietary rules for people with a history of intraperitoneal surgery to adopt during a flight.

Famous endoscopy quotes

These quotations, whether humorous or serious, provide insight into how gastroenterology nurses, gastroenterologists, and endoscopists feel about themselves as professionals, how other healthcare professionals perceive them, and their image in popular culture. Recognition of these aspects of gastroenterology nursing, gastroenterology, and endoscopy are important for self-improvement, correcting public misperceptions, and appreciating how patient misperceptions about gastroenterology nurses and gastroenterologists and patient attitudes toward endoscopy may present barriers that gastroenterology professionals must overcome to improve patient care. These quotations also fulfill a need for witticisms during dry endoscopy lectures!

Gastrointestinal tract imaging in children: current techniques

Imaging of the gastrointestinal (GI) tract in children continues to evolve, with new techniques, both radiological and non-radiological, being added to the repertoire. This article provides a summary of current imaging techniques of the GI tract (primarily the upper GI tract) and the relationship between those techniques. It covers the upper GI series and other contrast studies, US, CT and MRI. Note is also made of the contribution now made by capsule endoscopy (CE). Abdominal emergency imaging is not covered in this article.

High-risk chief complaints III: abdomen and extremities

Abdominal and extremity complaints are a frequent reason for presentation to the emergency department. Although these are common complaints, several abdominal and extremity disease entities may be missed or may be subject to delayed diagnosis. This article provides an overview of the diagnosis and management of several high-risk abdominal and extremity complaints, including appendicitis, abdominal aortic aneurysm, mesenteric ischemia, bowel obstruction, retained foreign body, hand and finger lacerations, fractures, and compartment syndrome. Each section focuses primarily on the pitfalls in diagnosis by highlighting the limitations of history, physical examination findings, and diagnostic testing and provides specific risk management strategies.

CT enteroclysis in incomplete small bowel obstruction

The timing of surgical intervention as well as the optimal method of radiologic investigation for patients with incomplete, open loop small bowel obstruction has changed over the past two decades. This review focuses on the role of computed tomographic enteroclysis in the evaluation of patients with suspected small bowel obstruction. The technique of examination is described and an overview of its clinical applications and imaging controversy are presented.

Location of the transition zone in CT of small-bowel obstruction: added value of multiplanar reformations

PURPOSE

To assess the additional value of multiplanar reformations (MPR) in comparison with axial images alone for location of the transition zone in CT of mechanical small-bowel obstruction (SBO).

MATERIALS AND METHODS

Sixty-nine consecutive patients with mechanical SBO underwent 16-slice multi detector row CT (MDCT). The gold standard for the precise location of the transition zone was established by two experienced abdominal radiologists, unblinded to clinical and surgical reports, reviewing all CT examinations. On a workstation, two blinded readers independently located the transition zone using first axial slices alone and then 1 month later MPR (axial, coronal, sagittal and oblique views) according to a three-point confidence scale. Diagnostic accuracy and mean confidence score were evaluated for both the transverse and multiplanar data sets.

RESULTS

Accuracy of transition zone location for reader 1 and reader 2 was 86% and 84% with axial slices alone, and by using MPR 93% (significant: P = 0.03) and 90% (not significant: P = 0.08), respectively. Mean confidence score was significantly increased for both readers using MPR: 0.3 higher (P = 0.0001) and 0.37 higher (P = 0.0001) respectively.

CONCLUSION

MPR can increase both accuracy and confidence in the location of the transition zone in CT of SBO.

Transnasal fine gastrointestinal fiberscope-guided long tube insertion for patients with small bowel obstruction

BACKGROUND

The use of a transnasal fine gastrointestinal fiberscope (TNF-GIF) has been rapidly disseminating in Japan. However, there has been no trial of long tube insertion (LTI) using the TNF-GIF for patients with small bowel obstruction (SBO).

PURPOSE

To examine whether TNF-GIF-guided LTI is superior to conventional LTI for patients with clinically diagnosed SBO.

METHODS

The time required for LTI was determined prospectively in each group of patients who underwent the conventional method (group 1, n = 10) and the TNF-GIF-guided method (group 2, n = 10) between March 2007 and November 2007. Insertion time was compared between groups 1 and 2.

RESULTS

Insertion time in group 2 was significantly shorter than that in group 1 (group 1, 22 +/- 16 min versus group 2, 9.2 +/- 5.4 min; P = 0.03).

CONCLUSIONS

Novel TNF-GIF-guided LTI is useful and superior to the conventional method.

CT enteroclysis in small bowel Crohn's disease

The diagnostic evaluation of small bowel Crohn's disease has changed dramatically over the last decade. The introduction of wireless capsule endoscopy, double balloon endoscopy and the introduction of newer therapeutic agents have changed the role of imaging in the small bowel. Additionally, advances in multidetector CT technology have further changed how radiologic investigations are utilized in the diagnosis and management of small bowel Crohn's disease. This article describes how we perform CT enteroclysis in the investigation of small bowel Crohn's disease and discusses the role of CT enteroclysis in the current management of small bowel Crohn's disease.

Small-bowel obstruction: state-of-the-art imaging and its role in clinical management

Small-bowel obstruction (SBO) is a common clinical condition with signs and symptoms similar to other acute abdominal disorders. The radiologic investigation of patients with SBO as well as the indications and timing of surgical intervention have changed over the past 2 decades. This review focuses on modern imaging techniques and their role in both the diagnosis and treatment of patients with SBO.

CT enteroclysis: techniques and applications

CT enteroclysis overcomes the individual deficiencies of both barium enteroclysis and conventional CT and combines the advantages of both into one technique whose clinical applicability has been simplified and made more reliable with multidetector CT technology. This article examines the techniques of CT enteroclysis and presents an overview of its clinical applications relative to other methods of small bowel imaging.

Partial small bowel obstruction and ileus following gynecologic laparoscopy

STUDY OBJECTIVE

To assess the incidence and management of partial small bowel obstruction (PSBO) and ileus after gynecologic endoscopy.

DESIGN

Internet-based cross-sectional survey (Canadian Task Force classification II-3).

MATERIAL AND METHODS

An online survey was distributed to gynecologic surgeons to collect information about frequency and management of ileus and PSBO after gynecologic laparoscopy.

MEASUREMENTS AND MAIN RESULTS

Of the 58 physician respondents, 22 had managed at least 1 patient with PSBO or ileus after gynecologic laparoscopy. A total of 12 PSBOs and 14 patients experiencing ileus were identified for an overall incidence of 0.036%. Patients showed symptoms between 1 and 20 days postoperatively and had findings ranging from hypoactive (45%), to normal (30%), to hyperactive (25%) bowel sounds. Plain film radiographs (75%) were the most commonly used diagnostic modality followed by computed tomography (CT) scans of the abdomen. Most patients were initially managed with intestinal rest and nasogastric tube placement for 2 to 16 days. Fifty percent required a second procedure, with reported findings that included intestinal herniation (n = 7), bowel injury (n = 4), volvulus (n = 2), and urinoma (n = 1).

CONCLUSION

Ileus and PSBO are rare findings after gynecologic laparoscopy. We identified 26 cases, most of which were initially managed conservatively. The majority of patients ultimately required a second operation. Surgeons should have a high index of suspicion when managing a patient with PSBO or ileus after gynecologic laparoscopy. Given the findings from the second procedures, CT scans would seem to be the diagnostic procedure of choice.

[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.

Management of complications in surgery of the colon

BACKGROUND

General surgeons are frequently confronted with colorectal diseases in their daily practice, whereby colorectal cancer is the second most common malignant tumour, with almost 5000 new cases every year in Austria. The incidence of benign colon disorders requiring surgery (e.g. colon polyps, sigmoid diverticulitis) is also increasing. The first aim in colon surgery should be to avoid complications and if they occur to treat them properly.

METHODS

We basically distinguish between general and special complications. As general complications, prevention of malnutrition and support of the immune system should receive special attention. As the number of elderly patients increases, so does the risk not only of thrombembolic complications but also of critical cardiocirculatory situations, and renal and hepatic failure. Special complications depend either on the type of surgery (laparoscopic assisted, conventional open surgery) or the techniques employed (stapled, hand sutured). Handling of the tissue also plays a major role (e.g. dry versus wet pads).

RESULTS

Shortening of the postoperative stay decreases both hospital costs and the incidence of infections, meaning that minimally invasive surgery and postoperative "fast track nutrition" should be promoted. Emergency operations should be avoided (e.g. bridging through colonic stents), as morbidity and mortality are clearly increased in comparison to (semi-) elective operations. During the operation itself, new equipment and techniques (such as Ultracision®, Ligasure®) as well as a well coordinated team help to reduce complications and duration of surgery.

CONCLUSIONS

To avoid is better than to repair. If complications do occur, appropriate surgical and intensive - care measures should be taken immediately.

Understanding neonatal bowel obstruction: building knowledge to advance practice

Providing care to neonates with bowel obstruction requires a basic understanding of gastrointestinal (GI) anatomy and functional landmarks as well as knowledge of the pathophysiology associated with intestinal blockage. Early recognition and prompt diagnosis necessitate astute assessment of common presenting symptoms and accurate interpretation of diagnostic investigations. Initial medical management is focused primarily on gastric decompression and maintenance of fluid and electrolyte balance. This article describes features of the neonatal GI tract and discusses common causes of neonatal bowel obstruction.

Advances in alimentary tract imaging

Advances in imaging techniques are changing the way radiologists undertake imaging of the gastrointestinal tract and their ability to answer questions posed by surgeons. In this paper we discuss the technological improvements of imaging studies that have occurred in the last few years and how these help to better diagnosing alimentary tract disease.

Multislice CT enteroclysis: technique and clinical applications

Computed tomography (CT) enteroclysis was introduced to overcome the individual deficiencies of barium enteroclysis and abdominal CT. The use of multislice CT technology has made the procedure a feasible extension of the intubation infusion method of small bowel examination. This review is an update of the technique and clinical application of CT enteroclysis with illustrations.

Small-bowel obstruction: coronal reformations from isotropic voxels at 16-section multi-detector row CT

PURPOSE

To retrospectively assess the added value of coronal reformations of the abdomen and pelvis from isotropic voxels by using 16-section multi-detector row computed tomography (CT) for the diagnosis of small-bowel obstruction (SBO).

MATERIALS AND METHODS

This HIPAA-compliant study was approved by the institutional review board of this medical center with a waiver of informed consent. One hundred consecutive patients (40 men and 60 women; mean age, 55 years) suspected of having SBO and abdominal pain underwent 16-section multi-detector row CT with coronal reformations. Twenty-nine patients had a final diagnosis of SBO, and 71 patients did not. Three independent readers blinded to the diagnosis interpreted the CT scout scan, then transverse scans alone, and then transverse plus coronal scans for the presence of SBO and abnormal wall enhancement. Confidence was scored with a 1-5 scale (1 = absent, 5 = present).

RESULTS

Mean sensitivity and specificity of CT scout alone, transverse CT alone, and transverse plus coronal CT for the diagnosis of SBO were 88% and 86%, 87% and 87%, and 87% and 90%, respectively (not significant). In patients without SBO, transverse plus coronal CT enhanced confidence in the exclusion of SBO (P = .01). In patients with SBO, transverse plus coronal CT enhanced confidence in the diagnosis of SBO and identification of abnormal wall enhancement (P = .01).

CONCLUSION

Transverse 16-section multi-detector row CT data sets are an excellent test for the diagnosis of SBO, while the addition of coronal reformations obtained from these isotropic data sets adds confidence to the diagnosis and exclusion of SBO.

Small-bowel complications of major gastrointestinal tract surgery

OBJECTIVE

Gastrointestinal complications of major abdominal surgery often require radiologic assessment. The purpose of this article is to review the expected imaging findings and complications after commonly performed gastric and pancreatic surgery.

CONCLUSION

It is important to understand the postsurgical anatomy to avoid misinterpreting an expected postoperative finding as a complication. Postoperative complications can be categorized as being related to adhesions, anastomosis, an enteric connection, and abnormal bowel position.

Imaging of small bowel-related complications following major abdominal surgery

To recognize and document the small bowel reactions following major abdominal surgery is an important key for a correct diagnosis. Usually, plain abdominal radiography is the initial imaging examination requested in the immediate postoperative period, whereas gastrointestinal contrast studies are used to look for specific complications. In some countries, especially in Europe, sonography is widely employed to evaluate any acute affection of the abdomen. CT is commonly used to assess postoperative abdominal complications; in our institution also CT enteroclysis is often performed, to provide additional important informations. Radiologist should be able to diagnose less common types of obstruction, such as afferent loop, closed loop, strangulating obstruction as well as internal hernia. This knowledge may assume a critical importance for surgeons to decide on therapy. In this article, we focus our attention on the imaging (particularly CT) in small bowel complications following abdominal surgery.

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.

The relevance of free fluid between intestinal loops detected by sonography in the clinical assessment of small bowel obstruction in adults

INTRODUCTION

The main role of the radiologist in the management of patients with suspicion of small bowel obstruction is to help triage patients into those that need immediate surgical intervention from those that require medical therapy or delayed surgery. Ultrasound examination is usually considered not helpful in bowel obstruction because of air in the intestinal lumen that interferes the evaluation of the intestinal loops, however recently some Authors attested the increasing important role of sonography in the acute abdominal disease. Aim of our report is to demonstrate the value of free fluid detected by US in differentiating between low and high-grade small bowel obstruction.

MATERIALS AND METHODS

The study is based on 742 consecutive patients who presented symptoms of the acute abdomen; all patients had undergone initial serial abdominal plain film and US examinations prior to any medical intervention. We reviewed the imaging findings of 150 cases in whom small bowel obstruction was clinically suspected and confirmed at surgery. We consider the following radiographic and US findings: dilatation of small bowel loops; bowel wall thickness; presence of air-fluid levels; thickness of valvulae conniventes; evidence of peristalsis; presence and echogenicity of extraluminal fluid. We looked at the value of extraluminal peritoneal fluid at US examination in differentiating low and high-grade small bowel obstruction based on the surgical outcome.

RESULTS

In 46 patients altered peristaltic activity, thin bowel walls, fluid filled loops with hyperechoic spots in the bowel segment proximal to obstruction were noted at US, whereas radiographic features were: moderate dilatation of small bowel loops, with thin bowel wall and evidence of numerous and subtle valvulae conniventes; presence of air-fluid levels was also noted. In 70 other patients, US examination revealed all the findings described in the precedent cases and also the presence of free extraluminal fluid; abdominal plain film showed an increased dilatation of small bowel loops with moderate thickened wall and air-fluid levels. In 34 other patients US examination revealed the presence of thick-walled loops, hypoperistalsis and a larger amount of free extraluminal fluid. Radiographic findings in these patients were: horizontal featured and markedly dilated small bowel loops presenting parietal thickness, presence of intraluminal fluid stasis and evidence of thickened, sparse and incomplete valvulae conniventes. At surgery etiology of small bowel obstructions was various, but most of cases related to adhesions (70 cases). The presence of extraluminal fluid were confirmed at surgery in 104 patients.

CONCLUSIONS

Our experience using sonography in suspicion of SBO (small bowel obstruction) suggests the usefulness of this imaging modality to differentiate a functional or obstructive ileus, demonstrating the evidence of intestinal peristalsis. Furthermore, the presence of a large amount of fluid between dilated small bowel loops suggests worsening mechanical small bowel obstruction, that requires not a medical therapy but immediate surgery.

The multifaceted role of radiology in small bowel obstruction

Small bowel obstruction is a common clinical condition, often presenting with signs and symptoms similar to those seen in other acute abdominal disorders. The diagnosis and treatment of this dynamic process continues 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 changes 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.

CT diagnosis of small bowel obstruction: scanning technique, interpretation and role in the diagnosis

Intestinal obstruction is a relatively common condition with diagnosis based on the clinical signs, patient history, and radiographical findings. Once suspected, its presence should be determined and if present, the site and cause of obstruction, and presence of strangulation should be assessed for the appropriate patient management. With the recent technological developments, the role of computed tomography (CT) in the diagnosis of bowel obstruction has expanded. The examination should be performed with intravenous contrast administration and thinner sections and multi-planner image reformation are recommended to evaluate a site of particular interest. CT is reported to have a sensitivity refer to detection of a small bowel obstruction at over 90% for complete or high-grade obstruction and to disclose causes of obstruction in 70% to 95% of cases. CT also provides characteristic findings indicating the presence of closed-loop obstruction and intestinal ischemia, which leads to appropriate and timely management for these emergent cases.

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.

Technical refinements in enteroclysis

As the primary method of investigating the small bowel, enteroclysis remains a technique in evolution. Technical refinements have made the examination faster to perform, better tolerated by patients, and easier to interpret. More recently, its essential principle of volume challenge has been combined with the tremendous advantage of CT cross-sectional imaging with multiplanar reformatting to give rise to the exciting new techniques of CT enteroclysis and MR enteroclysis (see separate reviews in this issue). Through improvements in methodology and advancements in technology, the future of enteroclysis looks bright indeed.

Multidetector-row helical CT enteroclysis

Currently, CT-E is not recommended as the first-line examination in patients when mucosal detail is required. Double-contrast barium air enteroclysis has advantages in demonstrating small mucosal abnormalities. The authors find CT-E of value in the work-up of patients with symptoms of intermittent small bowel obstruction, particularly those with a history of prior abdominal surgery; in the further work-up of selected patients with high-grade obstruction in whom general surgeons prefer initial conservative management (immediate postoperative small bowel obstruction, patients with history of prior abdominal surgery for malignant tumor, history of radiation treatment, and possible internal extraintestinal fistulae); in looking for complications of small bowel Crohn's disease; and in the patient with unexplained anemia or gastrointestinal bleeding. In a series of patients who had both abdominal CT and barium enteroclysis done, each examination provided unique and complimentary diagnostic information. Because CT-E combines the advantages of both methods of examination, is it the optimum imaging work-up in the investigation of small bowel disease? Further research and clinical experience will define the precise role of CT-E in the investigation of small bowel disease. Experience with this method of examination is limited to a few institutions, performed by investigators with interest in small bowel diseases. The addition of cross-sectional display and multiplanar reformatting made possible by multidetector-row helical CT to enteral volume change and the use of multifunctional nasointestinal catheters make CT-E an important tool in the investigation of small bowel disease. Experience has shown the increased reliability of any method of examining the small bowel that challenges intestinal wall distensibility by fluid enteral volume infusion.