The utility of computed tomography in acute small bowel obstruction

A Case-Based Overview of the Role of Radiological Imaging in Emergency General Surgery

This article aims to give an overview of some of the common conditions seen in emergency general surgery and the recommended choice of imaging. For junior doctors, choosing the correct imaging modality can be difficult so we aim to provide a summary of the evidence behind radiology for emergency general surgery. Four of the most important acute surgical conditions were chosen, alongside abdominal aortic aneurysm. A literature search was carried out to review the most up-to-date evidence regarding imaging choices. Cases were chosen from everyday practice to put the imaging into context. This article gives an overview of the most common imaging modalities used in emergency general surgery. It can be used by medical students and junior doctors to help understand the reasoning behind imaging choices on the acute surgical take.

Clinical Characteristics and Treatment Outcomes Among Patients With Gastrointestinal Phytobezoars: A Single-Institution Retrospective Cohort Study in Korea

Purpose: To describe our experience with phytobezoars, evaluate risk factors on treatment, and analyze whether previous gastric surgery affects treatment outcomes.

Methods: Medical records of 51 patients with phytobezoars between 2000 and 2019 were retrospectively evaluated. We compared endoscopic and surgical treatment groups and evaluated risk factors using multivariate logistic regression analysis. And we compared patients with and without previous gastric surgery in the surgical treatment group.

Results: The median patient age was 62.9 (range: 27–89) years. The endoscopic and surgical treatment groups included 26 (51%) and 25 (49%) patients, respectively. Patients aged ≥65 years, diabetes, and small intestinal phytobezoars were more frequent in the surgical treatment group. Previous gastric surgery (n = 16, 31.4%) was the most common predisposing risk factor, but without a significant difference between the groups. Enterotomy was performed for 20 patients (80%), segmental resection was performed for five patients (20%). Five patients (20%) had postoperative complications; there was one death. There were no significant differences in age, preoperative diagnosis, operation method, operative time, or postoperative stay between patients with and without previous gastric surgery, but postoperative complications were significantly more common in patients with previous gastric surgery.

Conclusions: Phytobezoar should be suspected early in patients with previous gastric surgery or a specific food intake history. Early diagnosis and treatment are important for avoiding surgical intervention and complications, especially in elderly patients. Surgery is required in most patients with small intestinal phytobezoars, safe removal can be achieved mainly via enterotomy.

Diagnostic performance of CT findings for bowel ischemia and necrosis in closed-loop small-bowel obstruction

PURPOSE

The aim of this study was to investigate the diagnostic performance of contrast-enhanced CT (CECT) findings for bowel ischemia and necrosis in closed-loop small-bowel obstruction (CL-SBO).

MATERIALS AND METHODS

Thirty-five patients with CL-SBO confirmed by laparotomy (n = 34) or multiplanar reconstruction of thin slice CT images (n = 1) were included. Based on the surgical and clinical findings, these patients were classified into three groups: necrosis group (n = 16), ischemia without necrosis group (n = 11), and no-ischemia group (n = 8). Two blinded radiologists retrospectively reviewed CECT including multiplanar reconstruction images and evaluated 12 CT findings. The sensitivity and specificity of each finding were compared among the three groups, and logistic regression analysis was performed.

RESULTS

High attenuation of the bowel wall, intraperitoneal air, reduced enhancement of the mesenteric arteries, and small-bowel feces signs showed high specificities of 100%, 100%, 89%, and 89% but low sensitivities of 31%, 25%, 44%, and 31%, respectively, for the prediction of bowel necrosis in CL-SBO. According to multivariate logistic regression analysis, reduced bowel-wall enhancement, reduced enhancement of the mesenteric veins, and a lack of engorgement of the mesenteric veins were significant for predicting bowel ischemia or necrosis (P < 0.05).

CONCLUSIONS

Reduced enhancements of bowel wall and mesenteric veins were good indicators of bowel ischemia or necrosis. On the contrary, engorgement of the mesenteric veins was a predictor of a viable bowel.

Multimodality approach for imaging of non-traumatic acute abdominal emergencies

"Acute abdomen" includes spectrum of medical and surgical conditions ranging from a less severe to life-threatening conditions in a patient presenting with severe abdominal pain that develops over a period of hours. Accurate and rapid diagnosis of these conditions helps in reducing related complications. Clinical assessment is often difficult due to availability of over-the-counter analgesics, leading to less specific physical findings. The key clinical decision is to determine whether surgical intervention is required. Laboratory and conventional radiographic findings are often non-specific. Thus, cross-sectional imaging plays a pivotal role for helping direct management of acute abdomen. Computed tomography is the primary imaging modality used for these cases due to fast image acquisition, although US is more specific for conditions such as acute cholecystitis. Magnetic resonance imaging or ultrasound is very helpful in patients who are particularly sensitive to radiation exposure, such as pregnant women and pediatric patients. In addition, MRI is an excellent problem-solving modality in certain conditions such as assessment for choledocholithiasis in patients with right upper quadrant pain. In this review, we discuss a multimodality approach for the usual causes of non-traumatic acute abdomen including acute appendicitis, diverticulitis, cholecystitis, and small bowel obstruction. A brief review of other relatively less frequent but important causes of acute abdomen, such as perforated viscus and bowel ischemia, is also included.

Surgical indicators for the operative treatment of acute mechanical intestinal obstruction due to adhesions

Purpose

Our aim was to investigate the predictive factors indicating strangulation, and the requirement for surgery in patients with acute mechanical intestinal obstruction due to adhesions.

Methods

This study retrospectively evaluated the records of patients with adhesive acute mechanical intestinal obstruction. The surgical treatment (group S), conservative treatment (group C), intraoperative bowel ischemia (group I), and intraoperative adhesion only (group A) groups were statistically evaluated according to the diagnostic and surgical parameters.

Results

The study group of 252 patients consisted of 113 women (44.8%), and 139 men (55.2%). The mean age was 62.79 ± 18.08 years (range, 20-98 years). Group S consisted of 50 patients (19.8%), and 202 (80.2%) were in group C. Group I consisted of 19 patients (38%), where as 31 (62%) were in group A. In group S, the prehospital symptomatic period was longer, incidence of fever was increased, and elevated CRP levels were significant (P < 0.05). Plain abdominal radiography, and abdominal computerized tomography were significantly sensitive for strangulation (P < 0.05). The elderly were more prone to strangulation (P < 0.05). Fever, rebound tendernes, and urea & creatinine levels were significantly higher in the presence of strangulation (P < 0.05, P < 0.05, and P < 0.05, consecutively).

Conclusion

Fever, rebound tenderness, urea & creatinine levels, plain abdominal radiography, and abdominal computerized tomography images were important indicators of bowel ischemia. Longer prehospital symptomatic period was related with a tendency for surgical treatment, and the elderly were more prone to strangulation. CRP detection was considered to be useful for the decision of surgery, but not significantly predictive for strangulation.

MR enterography in the evaluation of small bowel dilation

Magnetic reasonance (MR) enterography enables high contrast resolution depiction of the location and cause of bowel obstruction through a combination of predictable luminal distension and multiplanar imaging capabilities. Furthermore, because the patient is not exposed to ionizing radiation, sequential "dynamic" MR imaging can be performed repeatedly over time further facilitating depiction of the site and/or the cause of obstruction. With increasing availability of MR imaging and standardization of the oral contrast medium regimens, it is likely that this technique will assume an ever-increasing role in the evaluation of small bowel dilation in the coming years. We illustrate the utility of MR enterography in the evaluation of small bowel dilation, whether it be mechanical, functional (e.g., ileus), or related to infiltrative mural disease.

Value of multidetector CT in decision making regarding surgery in patients with small-bowel obstruction due to adhesion

The aim of this study was to evaluate the value of use of multidetector CT (MDCT) to predict the need for subsequent surgery in patients with small-bowel obstruction (SBO) due to adhesion. During a 3-year period, 128 patients with an SBO due to adhesion were enrolled in this prospective study. Initially, all patients were treated conservatively. Surgery was performed in patients who developed signs of strangulation or did not improve, despite a conservative treatment for at least 5 days. Of the 128 patients, 37 patients eventually underwent surgery. Two radiologists interpreted MDCT findings regarded as predictive indicators for subsequent surgery in consensus. The findings included degree of SBO, presence of transition zone, and an abnormal vascular course. These findings were statistically compared between the group operated on and the group not operated on. A higher degree of SBO, an abnormal vascular course, and the presence of transition zone were more frequently seen in the group of patients operated on (p < 0.001). Sensitivities, specificities, positive and negative predictive values, and risks for the use of MDCT to predict the need for surgery were 100%, 46.1%, 43%, 100%, and 1.9 (1.5 < or = 95% confidence interval (CI) < or = 2.2) for a high-grade obstruction; 100%, 23%, 34.5%, 100%, and 1.3 (1.2 < or = 95% CI < or = 1.5) for the presence of a transition zone; and 70.2%, 90.1%, 74.2%, 88.1%, and 7.1 (3.7 < or = 95% CI < or = 13.7) for the presence of an abnormal course of the mesenteric vessels, respectively. The presence of a high degree of SBO and an abnormal vascular course around transition zone are useful indicators on MDCT to predict the need for surgery in patients with an SBO due to adhesion.

Acute Abdominal Pain: Diagnostic Impact of Immediate CT Scanning

BACKGROUND

Acute abdominal pain is a common diagnostic problem. This study aimed to evaluate the routinely use of contrast enhanced computed tomographic (CT) scanning early in the diagnostic process.

METHODS

A retrospective review of 2,222 patients with acute abdominal pain who underwent contrast enhanced CT scanning within 24 h after admission. The diagnoses obtained were compared with the final diagnoses after 1 month.

RESULTS

After CT scanning the following diagnoses were suggested as the primary cause of the abdominal pain: nonspecific abdominal pain 984 (44.3%), appendicitis 354 (15.9%), bowel obstruction 190 (8.6%), diverticulitis 182 (8.2%), gastrointestinal perforation 52 (2.3%), gallstone disease 64 (2.9%), pancreatitis 72 (3.2%), inflammatory bowel disease 13 (0.6%), intra-abdominal malignancy 34 (1.5%), vascular disease (including 1 completely cured patient with paradoxical embolization in the superior mesenteric artery) 33 (1.5%), urological 131 (5.9%), gynecological 54 (2.4%), miscellaneous 31 (1.4%). In 28 cases a conclusive CT examination could not be carried out. The suggested diagnoses were correct in 2,151 cases (96.8%). In 16 cases (0.7%) an incorrect diagnosis was reported, leading to 7 unnecessary laparotomies. False negative reports were obtained in 27 cases (1.2%). After CT examination 500 patients could be discharged immediately.

CONCLUSIONS

Contrast-enhanced CT scanning results in superior diagnostic precision in patients with acute abdominal pain. The present work supports the strategy to include this examination early in the routine diagnostic process.

Small-bowel obstruction secondary to bezoar impaction: a diagnostic dilemma

BACKGROUND

Gastrointestinal bezoar (GIB) is uncommon and is reported to occur in 4% of all admissions for small-bowel obstruction (SBO). Because of a lack of diagnostic features, it is often associated with a delay in treatment, with increased morbidity. In this article, we report our experience with managing bezoar-induced SBO and the role of early computed tomography (CT) imaging in establishing the diagnosis.

METHODS

We retrospectively reviewed all cases of bezoar-induced SBO treated in our unit between 1999 and 2005.

RESULTS

There were 43 patients, of whom 2 had a recurrence, giving a total of 45 episodes. The frequency of bezoar in our patients presenting with SBO was 4.3%. All patients were of Asian origin: 41 Chinese, 1 Indian, and 1 Malay. Twenty-eight (65%) patients had previous abdominal surgery of which 26 were gastric surgery. Thirty-eight (88%) patients were edentulous. Forty-one (91%) underwent serial abdominal radiography, whereas only 4 patients (9%) had either CT imaging or contrast study alone. Only 11 (24%) cases had a correct diagnosis of bezoar impaction made preoperatively by CT imaging. The diagnostic accuracy of CT imaging in our series was 65%, with six cases of misdiagnosis. Overall, CT led to a change in management of 76% (13 in 17). The median time to surgery from admission was 2 (0-10) days. There were 2 cases of ischemic bowel that necessitated bowel resection. The median length of hospital stay was 11 (5-100) days. Ten patients (22%) had postoperative complications, and there was one death.

CONCLUSION

Bezoar-induced SBO is uncommon and remains a diagnostic and management challenge. It should be suspected in patients with an increased risk of formation of GIB, such as previous gastric surgery, poor dentition, and a suggestive history of increased fibre intake. We advocate that CT imaging be performed early in these at-risk patients and in patients presenting with SBO with or without a history of abdominal surgery in order to reduce unnecessary delays before appropriate surgical intervention.

[Surgical treatment of sclerosing encapsulating peritonitis]

OBJECTIVES

Sclerosing encapsulating peritonitis (SEP) or abdominal cocoon is a rare disease characterized by the formation of a fibrocollagenous membrane that wraps around the loops of the small bowel, producing obstruction. We present the results of the surgical treatment of this disease in three patients with chronic renal failure who developed SEP during the course of peritoneal dialysis (PD) and provide a literature review on the subject aimed at the general surgeon.

PATIENTS AND METHOD

In our area, the PD program treated 150 patients in 14 years, with seven cases of suspected SEP. In three patients, exploratory laparotomy was required. Clinical data, diagnostic imaging tests, type of surgery, immediate postoperative course, and status of the patient during subsequent follow-up are described.

RESULTS

In one of the three patients, bowel obstruction led to perforation requiring resection with anastomosis; the postoperative course was complicated and the patient died. In the remaining two patients, elective surgery was performed with the aim of removing the capsule enclosing the intestinal loops. In both patients the immediate postoperative course was favorable, although recurrence of intestinal encapsulation occurred in one patient.

CONCLUSIONS

The success of surgery in this disease is determined by the technique used. The correct technique consists of freeing the adhesions and extirpating of the capsule as far as possible. Perforation, as well as resection and intestinal anastomosis, significantly increase mortality.

Bowel obstruction: comparison between multidetector-row CT axial and coronal planes

Acute obstruction of bowel is a common reason for presentation to the emergency department. Causes of obstruction are multiple (tumorous, inflammatory, postoperative, or congenital), but the clinical presentation is usually not specific. The abdominal radiographs are sometimes inconclusive, and cause of obstruction is rarely detected. Computed tomography (CT) has been shown to be useful in revealing the site and the cause of obstruction. Although radiologists are skilled in the interpretation of CT scans in the axial plane, the development of multidetector-row CT coupled with fast reconstruction hardware and software has stimulated interest in viewing abdomen in coronal plane. In the evaluation of small bowel obstruction, coronal plane serves as a useful adjunct for the identification of the point of transition from dilated to decompressed bowel. On the other hand, in the evaluation of large bowel obstruction, coronal planes could replace axial images in the evaluation of the site and cause of obstruction, although the best values of confidence level in the diagnosis are reached when interpreting axial combined with coronal images.

Imaging of acute small-bowel obstruction

OBJECTIVE

The objective of this pictorial essay is to review the different imaging techniques used for diagnosing small-bowel obstruction.

CONCLUSION

Small-bowel obstruction is a common presentation, for which safe and effective management depends on a rapid and accurate diagnosis. Conventional radiographs remain the first line of imaging. CT is used increasingly more because it provides essential diagnostic information not apparent from radiographs. MRI may play a role in the future as technology improves and it becomes more readily available.

Complex presentation of intussusception in childhood

The simultaneous occurrence of intussusception and volvulus in the paediatric age group is rare. We report the case of a volvulus of an ileoileal intussusception in an 8-year-old boy. This is the first time that computerised tomography (CT) images of a volvulus of an ileoileal intussusception have been published, and they clearly demonstrate both pathologies. This case highlights the use of CT in determining the nature of an abdominal mass and demonstrates how helpful it can be in diagnosing the cause of small bowel obstruction in children.

Multislice CT of the abdomen

Major advances have been made in CT technology since its introduction 30 years ago. Examination time has been markedly reduced and it is possible to cover considerably larger scan ranges. Multidetector technology now allows near isotopic imaging with the ability to perform high quality multiplanar reconstructions. It is also now possible to image in well defined vascular phases. In this article we share our experience in the use of multislice CT and detail protocols used in imaging of the abdomen.

Modern imaging using computer tomography and magnetic resonance imaging for inflammatory bowel disease (IBD) AU1

Radiologic imaging--especially of the small bowel--plays an important role in the diagnosis and management of patients with inflammatory bowel disease. The radiographic examination of the small intestine with barium either as enteroclysis or as small bowel follow through are still the mainstays in small bowel imaging. However, abdominal CT or MRI, which has the advantage of not utilizing ionizing radiation, or the techniques of CT- or MR-enteroclysis, are overall comparable with regard to the sensitivity and specificity in detecting intestinal pathologies and have already replaced the conventional techniques in centers dedicated to the management of inflammatory bowel disease. Additionally, these cross-sectional imaging techniques provide, in a sense, a "one stop abdominal imaging workup," the diagnosis of extraluminal disease manifestations or complications. Future developments of CT- or MR-based virtual colonography and endoscopy in patients with inflammatory bowel disease are currently being investigated, but should momentarily be considered as purely experimental approaches.

CT findings in patients with small bowel obstruction due to phytobezoar

The role of CT in evaluating patients with small bowel obstruction (SBO) has been extensively described in the current literature. We present the CT findings of SBO due to a phytobezoar, afterwards surgically confirmed, in 5 men and 1 woman (aged 32-89 years) out of 95 patients diagnosed by CT as having SBO in a 44-month period. These six patients underwent abdominal CT prior to operation and the CT findings were retrospectively reviewed. All six patients presented with clinical symptoms and signs of SBO; three of them had undergone gastric surgery 13, 17, and 22 years earlier, respectively. In all six cases, CT showed an ovoid intraluminal mass, 3 x 5 cm in size and of a mottled appearance, at the transition zone between dilated and collapsed small bowel loops. This was in contrast to feces-like material (the "small bowel feces sign"), seen within dilated small bowel loops in nine patients with SBO, and was typically longer. As CT is frequently performed for suspected SBO, an ovoid, short intraluminal mottled mass seen at the site of an obstruction may be regarded as a pathognomonic preoperative sign of an obstructing phytobezoar.

CT findings of afferent loop syndrome after a subtotal gastrectomy with Roux-en-Y reconstruction

A rare case of combined afferent loop syndrome following Roux-en Y reconstruction and small bowel obstruction due to adhesions at the enteroenterostomy is presented. The CT findings of the obstruction of both the afferent and the efferent limbs are demonstrated, with emphasis on the characteristic CT features of afferent loop syndrome.

Acute small bowel ischemia: CT imaging findings

Small bowel ischemia is a disorder related to a variety of conditions resulting in interruption or reduction of the blood supply of the small intestine. It may present with various clinical and radiologic manifestations, and ranges pathologically from localized transient ischemia to catastrophic necrosis of the intestinal tract. The primary causes of insufficient blood flow to the small intestine are various and include thromboembolism (50% of cases), nonocclusive causes, bowel obstruction, neoplasms, vasculitis, abdominal inflammatory conditions, trauma, chemotherapy, radiation, and corrosive injury. Computed tomography (CT) can demonstrate changes because of ischemic bowel accurately, may be helpful in determining the primary cause of ischemia, and can demonstrate important coexistent findings or complications. However, common CT findings in acute small bowel ischemia are not specific and, therefore, it is often a combination of clinical, laboratory and radiologic signs that may lead to a correct diagnosis. Understanding the pathogenesis of various conditions leading to mesenteric ischemia and being familiar with the spectrum of diagnostic CT signs may help the radiologist recognize ischemic small bowel disease and avoid delayed diagnosis. The aim of this article is to provide a review of the pathogenesis and various causes of acute small bowel ischemia and to demonstrate the contribution of CT in the diagnosis of this complex disease.

CT findings in patients with familial Mediterranean fever during an acute abdominal attack

The aim of this study is to present the abdominal CT findings of patients with familial Mediterranean fever (FMF) examined during an acute abdominal attack. CT scans of 17 patients (10 women and 7 men; age range 11-45 years) were retrospectively reviewed. Attention was directed to mesenteric or peritoneal abnormalities and to the presence of appendiceal pathology. Patients were divided into two groups; group A (n=14) consisted of patients with an acute abdominal attack caused by FMF, and group B (n=3) consisted of patients whose attack proved to be owing to a separate pathology requiring surgery. Characteristic CT findings of acute abdomen in FMF included mesenteric pathology (n=12), mainly of engorged vessels with thickened mesenteric folds, mesenteric lymphadenopathy (n=6) and ascites (n=6). Signs of focal peritonitis were found in four patients. Radiologists should be familiar with such CT findings of peritoneal irritation in patients with FMF during an acute attack, and may suggest this clinical diagnosis in the proper clinical setting in a patient who has not been previously diagnosed. Alternatively, the radiologist should be aware of the possibility of a concurrent acute appendicitis or other acute abdominal pathology in patients with known FMF and should search for it.

Enteroclysis and computed tomography enteroclysis

Enteroclysis, the most detailed radiologic examination of the small bowel, can be a challenge for both patient and radiologist. This article broadly outlines the principal technical features of the standard enteroclysis procedure and discusses its diagnostic advantages and indications, as well as its limitations and difficulties. A comparative assessment of computed tomography-enteroclysis and the emerging magnetic resonance adaptation complements the survey of current approaches to radiologic small bowel diagnostics.

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.