Obstruction of the small intestine: accuracy and role of CT in diagnosis

Deep learning for automatic bowel-obstruction identification on abdominal CT

RATIONALE AND OBJECTIVES

Automated evaluation of abdominal computed tomography (CT) scans should help radiologists manage their massive workloads, thereby leading to earlier diagnoses and better patient outcomes. Our objective was to develop a machine-learning model capable of reliably identifying suspected bowel obstruction (BO) on abdominal CT.

MATERIALS AND METHODS

The internal dataset comprised 1345 abdominal CTs obtained in 2015-2022 from 1273 patients with suspected BO; among them, 670 were annotated as BO yes/no by an experienced abdominal radiologist. The external dataset consisted of 88 radiologist-annotated CTs. We developed a full preprocessing pipeline for abdominal CT comprising a model to locate the abdominal-pelvic region and another model to crop the 3D scan around the body. We built, trained, and tested several neural-network architectures for the binary classification (BO, yes/no) of each CT. F1 and balanced accuracy scores were computed to assess model performance.

RESULTS

The mixed convolutional network pretrained on a Kinetics 400 dataset achieved the best results: with the internal dataset, the F1 score was 0.92, balanced accuracy 0.86, and sensitivity 0.93; with the external dataset, the corresponding values were 0.89, 0.89, and 0.89. When calibrated on sensitivity, this model produced 1.00 sensitivity, 0.84 specificity, and an F1 score of 0.88 with the internal dataset; corresponding values were 0.98, 0.76, and 0.87 with the external dataset.

CONCLUSION

The 3D mixed convolutional neural network developed here shows great potential for the automated binary classification (BO yes/no) of abdominal CT scans from patients with suspected BO.

CLINICAL RELEVANCE STATEMENT

The 3D mixed CNN automates bowel obstruction classification, potentially automating patient selection and CT prioritization, leading to an enhanced radiologist workflow.

KEY POINTS

• Bowel obstruction's rising incidence strains radiologists. AI can aid urgent CT readings. • Employed 1345 CT scans, neural networks for bowel obstruction detection, achieving high accuracy and sensitivity on external testing. • 3D mixed CNN automates CT reading prioritization effectively and speeds up bowel obstruction diagnosis.

Deep learning using computed tomography to identify high-risk patients for acute small bowel obstruction: development and validation of a prediction model : a retrospective cohort study

OBJECTIVE

To build a novel classifier using an optimized 3D-convolutional neural network for predicting high-grade small bowel obstruction (HGSBO).

SUMMARY BACKGROUND DATA

Acute SBO is one of the most common acute abdominal diseases requiring urgent surgery. While artificial intelligence and abdominal computed tomography (CT) have been used to determine surgical treatment, differentiating normal cases, HGSBO requiring emergency surgery, and low-grade SBO (LGSBO) or paralytic ileus is difficult.

METHODS

A deep learning classifier was used to predict high-risk acute SBO patients using CT images at a tertiary hospital. Images from three groups of subjects (normal, nonsurgical, and surgical) were extracted; the dataset used in the study included 578 cases from 250 normal subjects, with 209 HGSBO and 119 LGSBO patients; over 38 000 CT images were used. Data were analyzed from 1 June 2022 to 5 February 2023. The classification performance was assessed based on accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve.

RESULTS

After fivefold cross-validation, the WideResNet classifier using dual-branch architecture with depth retention pooling achieved an accuracy of 72.6%, an area under receiver operating characteristic of 0.90, a sensitivity of 72.6%, a specificity of 86.3%, a positive predictive value of 74.1%, and a negative predictive value of 86.6% on all the test sets.

CONCLUSIONS

These results show the satisfactory performance of the deep learning classifier in predicting HGSBO compared to the previous machine learning model. The novel 3D classifier with dual-branch architecture and depth retention pooling based on artificial intelligence algorithms could be a reliable screening and decision-support tool for high-risk patients with SBO.

Evaluation of symptomatic small bowel stricture in Crohn's disease by double-balloon endoscopy

PURPOSE

To assess the efficacy of double-balloon endoscopy (DBE) for the detection of small-bowel strictures in Crohn's disease (CD).

METHODS

This tertiary-referral hospital cohort study was conducted between January 2018 and May 2022. CD patients with symptoms of small-bowel stricture were enrolled sequentially. All of the patients were subjected to both computed tomography enterography (CTE) and DBE, and their symptoms of stricture were assessed using the Crohn's Disease Obstructive Score (CDOS). The diagnostic yield of DBE was compared to that of CTE, and the relationship between the DBE findings and CDOS was investigated. The factors influencing the DBE diagnosis were examined using Cox regression analysis.

RESULTS

This study included 165 CD patients. The CDOS scores were higher in 95 patients and lower in 70 patients. DBE detected 92.7% (153/165) and CTE detected 85.5% (141/165) of the strictures. The DBE diagnostic yields were 94.7% (90/95) in the high CDOS patients and 91.4% (64/70) in the low CDOS patients (P = 0.13). Patients with a history of abdominal surgery and abscess had a lower diagnosis rate in the multivariate analysis.

CONCLUSION

DBE has been demonstrated to be an efficient diagnostic method for detecting small bowel strictures in CD patients. Additionally, there was no difference in the diagnostic yields between patients with low and high obstructive scores.

ACR Appropriateness Criteria® Suspected Small-Bowel Obstruction

Small-bowel obstruction is a common cause of abdominal pain and accounts for a significant proportion of hospital admissions. Radiologic imaging plays the key role in the diagnosis and management of small-bowel obstruction as neither patient presentation, the clinical examination, nor laboratory testing are sufficiently sensitive or specific enough to diagnose or guide management. This document focuses on the imaging evaluation of the two most commonly encountered clinical scenarios related to small-bowel obstruction: the acute presentation and the more indolent, low-grade, or intermittent presentation. This document hopes to clarify the appropriate utilization of the many imaging procedures that are available and commonly employed in these clinical settings. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Diagnostic significance of multidetector computed tomography (MDCT) in patients with small bowel obstruction: a meta-analysis

PURPOSE

To assess the diagnostic value of multidetector computed tomography (MDCT) in small bowel obstruction (SBO) patients.

METHODS

Relevant literature was searched from the Cochrane Library, Pubmed and Embase. The extracted effective data was calculated using the Meta-Disc 1.4 software; statistical heterogeneity was evaluated using Cochran's Q test and I².

RESULTS

A total of five articles were selected for the meta-analysis. In addition, the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), as well as the diagnostic odds ratio (DOR) were 0.878 (95% CI 0.822-0.921), 0.807 (95% CI 0.753-0.854), 8.137 (95% CI 2.268-29.192), 0.127 (95% CI 0.040-0.4078) and 72.384 (95% CI 10.841-483.31), respectively. Furthermore, the AUC was 0.9648 with the Q of 0.9116.

CONCLUSIONS

The data suggest that MDCT is an effective method for diagnosis of SBO.

Diagnostic utility of CT for small bowel obstruction: Systematic review and meta-analysis

BACKGROUND

To perform a systematic review and meta-analysis evaluating the diagnostic performance of computed tomography (CT) for small bowel obstruction (SBO), including diagnostic accuracy, ischemia, predicting surgical intervention, etiology and transition point.

METHODS

PubMed/MEDLINE and related databases were searched for research articles published from their inception through August 2018. Findings were pooled using bivariate random-effects and summary receiver operating characteristic curve models. Meta-regression and subgroup analyses were performed to evaluate whether publication year, patient age, enhanced CT, slice thickness and pathogenesis affected classification accuracy.

RESULTS

In total, 45 studies with a total of 4004 patients were included in the analysis. The pooled sensitivity and specificity of CT for SBO were 91% (95% confidence interval [CI]: 84%, 95%) and 89% (95% CI: 81%, 94%), respectively, and there were no differences in the subgroup analyses of age, publication year, enhanced CT and slice thickness. For ischemia, the pooled sensitivity and specificity was 82% (95% CI: 67%, 91%) and 92% (95% CI: 86%, 95%), respectively. No difference was found between enhanced and unenhanced CT based on subgroup analysis; however, high sensitivity was found in adhesive SBO compared with routine causes (96% vs. 78%, P = 0.03). The pooled sensitivity and specificity for predicting surgical intervention were 87% and 73%, respectively. The accuracy for etiology of adhesions, hernia and tumor was 95%, 70% and 82%, respectively. In addition, the pooled sensitivity and specificity for transition point was 92% and 77%, respectively.

CONCLUSIONS

CT has considerable accuracy in diagnosis of SBO, ischemia, predicting surgical intervention, etiology and transition point.

Detection of Transition Zone in Bowel Obstruction via Curved Multiplanar Reformations with Multidetector Computed Tomography

Objective

We conducted this study to determine the added value of curved multiplanar reformations (CMPR) and multiplanar reformations (MPR) of multidetector computed tomography (MDCT) scan in the visualization and localization of the zone of transition in patients with intestinal obstruction.

Materials and methods

A total of 100 patients with suspected bowel obstruction were evaluated in a retrospective cross-sectional study from September 2016 to September 2018 at Dr. Ziauddin University Hospital, Clifton Campus. All patients underwent multidetector computed tomography (CT) scans with oral and intravenous contrast before surgical exploration. CMPR and MPR were acquired at the time of examination in each patient in addition to routine axial images. The CT scans were analyzed by two independent, experienced radiologists skilled at detecting the zones of transition in patients with bowel obstruction using the axial images alone, followed by axial images along with MPR, and then MPR plus CMPR. Patient data were masked to the radiologists. The CT scan findings were compared with surgical findings to determine the accuracy of CMPR in detecting the zone of transition between distended and collapsed bowel loops. The added CMPR showed high accuracy in the diagnosis of intestinal obstruction with a remarkable advantage over the conventional axial images. Data analysis was done on IBM SPSS Statistics for Windows, Version 20.0 (IBM Corp., Armonk, NY). Cohen’s kappa statistics were obtained to show the measure of agreement between the two readers. McNemar’s test was also applied to determine the homogeneity.

Results

Two radiologists, one with two years of experience and the other with five years of experience were 80% and 81% accurate, respectively, in identifying the zones of transition using axial images alone. Using axial images plus MPR, their accuracy was 88% and 92%, respectively. Using MPR plus CMPR, their accuracy was 96% and 98%, respectively. The accuracy of MPR plus CMPR views was significantly increased when compared to the accuracy using axial images alone. CT findings were compared to surgical findings in terms of diagnostic performance. The kappa value of 0.6 indicates moderate association and substantial agreement between two radiologists. McNemar’s test showed homogeneity in the number of valid cases.

Conclusion

CMPR is an important and accurate technique for evaluating intestinal obstruction in addition to MPR as it helps in better localization of the zone of transition and in determining the cause of obstruction. This insight provides guidance for the appropriate treatment.

Accuracy of Plain Abdominal Radiography in the Differentiation between Small Bowel Obstruction and Small Bowel Ileus in Acute Abdomen Presenting to Emergency Department

Introduction

Our purpose was to evaluate whether plain abdominal radiography (PAR) could accurately differentiate between small bowel obstruction (SBO) and small bowel ileus (SBI) in an emergency setting. We also evaluated the value of known classic signs on the PAR for differentiating between SBO and SBI.

Methods

This retrospective study included 216 emergency room patients who had small bowel distension (maximal small bowel diameter ≥2.5 cm) on the PAR and who underwent successive abdominal computed tomography. One radiologist and one emergency physician retrospectively reviewed PAR in consensus, unaware of the patients' clinical data; they divided the patients into an SBO group and an SBI group according to the radiographic findings. Presence or numeric values of 10 radiographic signs were also recorded. Final diagnoses of SBO and SBI were established by a combined analysis of medical charts, surgical records, radiographic findings on abdominal computed tomography, and small bowel studies. The differential diagnoses based on PAR and the final diagnoses were compared, and the sensitivity and specificity of PAR were calculated. We also evaluated the differences among 10 radiographic signs between the final SBO and SBI groups.

Results

Sensitivity and specificity of PAR for SBO were 82.0% and 92.4%, respectively. Among the 10 radiographic signs, all except maximal colon diameter were statistically significant predictors on the final diagnosis.

Conclusions

PAR is an accurate and effective initial imaging modality for differentiating between SBO and SBI in an emergency setting, and most of the classic radiographic signs have a diagnostic value.

Use of Postmortem Computed Tomography to Detect Bowel Obstruction and its Relationship to the Cause of Death

Bowel distension frequently indicates bowel obstruction, which is a common diagnosis in clinical radiology. Typically, symptoms and complaints lead to radiological examinations and the detection of the etiology. Untreated intestinal obstructions can lead to a fatal outcome through cardiac failure due to septic shock. Certain of these cases undergo medicolegal investigations depending on the case history, the condition of the decedent, the location of the finding, or recent visits to medical professionals. Computed tomography (CT) is a recommended method in clinical radiology for the detection of bowel obstruction, which is indicated by bowel distension and further radiological signs (eg, the whirl sign, which indicates a volvulus). Postmortem CT (PMCT) has increased worldwide, but PMCT differs from clinical CT; thus, the question of whether PMCT is also reliable for the detection of bowel obstruction in decedents or is negatively affected by postmortem modifications should be discussed. This study consists of 10 cases displaying radiological signs of bowel obstruction. Apart from bowel distension, the most common radiological signs (whirl sign, coffee bean sign, bird beak sign, and u-shape sign) are described and depicted. All decedents underwent autopsy and had a postmortem interval of less than 72 hours. Based on these cases, we assess the reliability of PMCT for detecting bowel obstruction and determining its relationship to the cause of death.

Impact of high-grade obstruction on outcomes in patients with appendiceal inflammatory masses managed by nonoperative treatment

Purpose

To retrospectively assess the impact of high-grade obstructions identified on initial CT on outcomes of patients with appendiceal inflammatory masses managed by nonoperative treatment.

Methods

Institutional Review Boards approved this retrospective study and informed consent was waived. Included were 52 consecutive patients diagnosed with appendiceal inflammatory masses by CT scan and managed by nonoperative treatment. The main outcome measure was treatment failure and secondary outcomes were complications and initial and total hospital stay. Patient demographics, inflammatory markers, and CT findings for presence of an appendiceal inflammatory mass and high-grade obstruction were assessed. Patients with and without high-grade obstruction were compared for patient characteristics and outcomes using Fisher exact test and Student t-test.

Results

Among 52 patients, 14 (27%) had high-grade obstruction on CT examination at presentation. No significant differences were observed in patient characteristics (P > 0.05), treatment failure (P = 0.33), complications (P = 0.29), or initial (P = 0.73) or total (P = 0.72) hospitalization between patients with and without high-grade obstruction.

Conclusion

For patients who were managed by nonoperative treatment for appendiceal inflammatory masses, the presence of high-grade obstruction identified on initial CT scan did not significantly affect outcomes of treatment failure, complications, and initial and total hospitalization.

Pre-operative CT predictors associated with 30-day adverse events in patients with appendiceal inflammatory masses who underwent immediate appendectomies

PURPOSE

To retrospectively evaluate pre-operative CT predictors that are associated with 30-day adverse events in patients who underwent immediate appendectomies for appendiceal inflammatory masses.

METHODS

This retrospective study was approved by our institutional review board, and the requirement for informed consent was waived. One hundred forty-four consecutive patients who underwent immediate appendectomies and were diagnosed with appendiceal inflammatory masses by pre-operative CT from January 2005 to December 2013 at a tertiary hospital were included. The main outcome measure was 30-day adverse events. Patient demographics and data for inflammatory markers including leukocyte counts, segmented neutrophils, and C-reactive protein levels were collected by a single radiologist. Pre- and post-operative CT findings were evaluated for features of appendiceal inflammatory masses, associated findings, and post-operative adverse events by two radiologists in a blinded fashion with consensus to assess surgical and pathologic results, post-operative outcomes, and original CT interpretations. Appendiceal inflammatory masses were defined as complicated appendicitis with a phlegmon or an abscess that was identified on pre-operative CT exam. Factors associated with 30-day adverse events were assessed using logistic regression analysis.

RESULTS

A total of 22 (15%) of the 144 patients (mean age [±SD] 44.6 ± 22.0 years, range 3-97 years) experienced 30-day adverse events: ten intra-abdominal abscesses, three wound infections, two cases of peritonitis, two small bowel obstructions, two intra-abdominal abscesses with peritonitis, one intra-abdominal abscess with wound infection, one intra-abdominal abscess with small bowel obstruction, and one case of peritonitis with small bowel obstruction. In univariate analysis, the presence of appendicolith (odds ratio [OR] 2.49, p = 0.048) and high-grade obstruction (OR 3.79; p = 0.01) were associated with adverse events. High-grade obstruction (adjusted OR 3.05; p = 0.04) was the only independent pre-operative predictor associated with 30-day adverse events in patients with appendiceal inflammatory masses.

CONCLUSIONS

High-grade obstruction was an independent pre-operative CT predictor associated with 30-day adverse events in patients who underwent immediate appendectomies for appendiceal inflammatory masses.

COMPARISON OF COMPUTED TOMOGRAPHY AND ABDOMINAL RADIOGRAPHY FOR DETECTION OF CANINE MECHANICAL INTESTINAL OBSTRUCTION

Vomiting, often caused by mechanical intestinal obstruction, is common in dogs. Equivocal radiographic signs often necessitate repeat radiographs or additional imaging procedures. For our prospective, case-controlled, accuracy study, we hypothesized the following: (1) using computed tomography (CT), radiologists will be more sensitive and specific for detecting mechanical intestinal obstruction and recommending surgery compared to using radiographs; and (2) using measurements, radiologists will be more sensitive and specific using radiographs or CT for detecting mechanical intestinal obstruction and recommending surgery. Twenty dogs had abdominal radiographs and abdominal CT. Seventeen dogs had abdominal surgery and three dogs were not obstructed based on clinical follow-up. Confidence levels (five-point scale) of three experienced radiologists for mechanical intestinal obstruction and recommending surgery were recorded before and after making selected measurements. Eight dogs had surgically confirmed mechanical intestinal obstruction, and 12 dogs did not have obstruction. For detecting mechanical intestinal obstruction, CT was more sensitive (95.8% vs. 79.2%) and specific (80.6% vs. 69.4%) compared to radiographs, but the difference was not statistically significant. For recommending surgery, radiography was more sensitive (91.7% vs. 83.3%) and specific (83.3% vs. 72.2%) than using CT, but differences were not statistically significant. We reported objective CT measurements for predicting small mechanical intestinal obstruction. By incorporating these objective data, the diagnosis of mechanical intestinal obstruction changed in five of 120 instances (radiographs and CT). In no instance (0/120), did the objective data change the recommendation for surgery. Using CT or abdominal radiographs for the detection of canine mechanical intestinal obstruction is sensitive and specific when evaluated by experienced veterinary radiologists.

Relative accuracy of emergency CT in adults with non-traumatic abdominal pain

OBJECTIVE

CT examination prior to emergency laparotomy has become ubiquitous in contemporary clinical practice, but the relative accuracy of CT in this context has not been widely reported. The aim of this study was to determine the accuracy and strength of agreement between the perceived pre-operative CT diagnosis and operative findings.

METHODS

Data from patients undergoing pre-operative CT prior to emergency laparotomy from January 2013 to June 2014 in a large teaching hospital were analysed. The CT diagnosis was compared with operative findings using the χ(2) test and weighted kappa statistic (Kw). Results were further analysed related to the time of day the CT was reported, anatomical location and grade of the reporting radiologist.

RESULTS

361 patients [median age 67 years (18-98 years); 180 males] underwent CT prior to emergency laparotomy. CT reports were deemed accurate in 318 (88.1%) cases and inaccurate in 43 (11.9%) cases, which resulted in 5 negative laparotomies in this latter cohort (11.6%, χ(2) 37.50, df 1; p < 0.0001). Accuracy and strength of agreement varied with anatomical location of the pathology; upper gastrointestinal (UGI) 75.5%, Kw 0.673 (0.531-0.815; p < 0.001); small bowel 89.9%, Kw 0.781 (0.687-0.875, p < 0.001); lower gastrointestinal (LGI) 90.4%, Kw 0.821 (0.749-0.893; p < 0.001). CT examinations reported within normal working hours had higher strength of agreement [Kw 0.832 (0.768-0.896), p < 0.001] than CTs reported out of hours [Kw 0.789 (0.721-0.857), p < 0.001], but there was no significant difference in overall accuracy (89.9 vs 86.0%; χ(2) 1.306, df 1, p = 0.253). Reporter seniority was not associated with improved diagnostic accuracy (χ(2) 1.825, df 1; p = 0.177).

CONCLUSION

CT agreement with emergency operative pathology was good to excellent, but the strength of agreement varied in relation to anatomical location of pathology.

ADVANCES IN KNOWLEDGE

Overall accuracy was 88.1% with good to excellent agreement between pre-operative CT and emergency laparotomy findings in adult patients with non-traumatic abdominal pain in the acute setting. Diagnostic accuracy of CT reporting varies with anatomical location of pathology.

Early diagnosis of bowel obstruction and strangulation by computed tomography in emergency department

BACKGROUND

Closed loop bowel obstruction is a specific type of mechanical obstruction with a high risk of strangulation and bowel infarction, especially in the small bowel. It is associated with a high mortality rate. Hence, it is important for emergency physicians to identify the presence of strangulation, while making the diagnosis of closed loop small bowel obstruction.

METHODS

We reported three patients with strangulated closed loop small bowel obstruction associated with severe abdominal pain, who had been treated at the emergency department. Urgent computerized tomography was performed in the patients.

RESULTS

Two patients were discharged with stable conditions, and one patient died after hemodialysis.

CONCLUSION

Urgent computerized tomography of the abdomen serves as an important diagnostic tool in view of its ability to detect the site, level and cause of obstruction along with the distinctive CT appearance of closed loop small bowel obstruction and signs of ischemia. Early definitive diagnosis will guide subsequent management and improve outcomes.

MDCT of Small Bowel Obstruction: How Reliable Are Oblique Reformatted Images in Localizing Point of Transition?

The goal of this study is to prospectively assess the additional value of oblique reformatted images for localizing POT, having surgery as a reference standard. Materials and Methods. 102 consecutive patients with suspected small bowel obstruction (SBO) underwent 64-slice multidetector row CT (MDCT) using surgical findings as reference standard. Two independent GI radiologists reviewed the CT scans to localize the exact POT by evaluating axial images (data set A) followed by axial, coronal, and oblique MPR images. CT findings were compared to surgical findings in terms of diagnostic performance. McNemar's test was used to detect any statistical difference in POT evaluation between datasets A and B. Kappa statistics were applied for measuring agreement between two readers. Results. There was a diagnostic improvement of 9.9% in the case of the less experienced radiologist in localizing POT by using oblique reformatted images. The more experienced radiologist showed diagnostic improvement by 12.9%.

Adult small bowel obstruction

BACKGROUND

Small bowel obstruction (SBO) is a clinical condition that is often initially diagnosed and managed in the emergency department (ED). The high rates of potential complications that are associated with an SBO make it essential for the emergency physician (EP) to make a timely and accurate diagnosis.

OBJECTIVES

The primary objective was to perform a systematic review and meta-analysis of the history, physical examination, and imaging modalities associated with the diagnosis of SBO. The secondary objectives were to identify the prevalence of SBO in prospective ED-based studies of adult abdominal pain and to apply Pauker and Kassirer's threshold approach to clinical decision-making to the diagnosis and management of SBO.

METHODS

MEDLINE, EMBASE, major emergency medicine (EM) textbooks, and the bibliographies of selected articles were scanned for studies that assessed one or more components of the history, physical examination, or diagnostic imaging modalities used for the diagnosis of SBO. The selected articles underwent a quality assessment by two of the authors using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Data used to compile sensitivities and specificities were obtained from these studies and a meta-analysis was performed on those that examined the same historical component, physical examination technique, or diagnostic test. Separate information on the prevalence and management of SBO was used in conjunction with the meta-analysis findings of computed tomography (CT) to determine the test and treatment threshold.

RESULTS

The prevalence of SBO in the ED was determined to be approximately 2% of all patients who present with abdominal pain. Having a previous history of abdominal surgery, constipation, abnormal bowel sounds, and/or abdominal distention on examination were the best history and physical examination predictors of SBO. X-ray was determined to be the least useful imaging modality for the diagnosis of SBO, with a pooled positive likelihood ratio (+LR) of 1.64 (95% confidence interval [CI] = 1.07 to 2.52). On the other hand, CT and magnetic resonance imaging (MRI) were both quite accurate in diagnosing SBO with +LRs of 3.6 (5- to 10-mm slices, 95% CI = 2.3 to 5.4) and 6.77 (95% CI = 2.13 to 21.55), respectively. Although limited to only a select number of studies, the use of ultrasound (US) was determined to be superior to all other imaging modalities, with a +LR of 14.1 (95% CI = 3.57 to 55.66) and a negative likelihood ratio (-LR) of 0.13 (95% CI = 0.08 to 0.20) for formal scans and a +LR of 9.55 (95% CI = 2.16 to 42.21) and a -LR of 0.04 (95% CI = 0.01 to 0.13) for beside scans. Using the CT results of the meta-analysis for the 5- to 10-mm slice subgroup as well as information on intravenous (IV) contrast reactions and nasogastric (NG) intubation management, the pretest probability threshold for further testing was determined to be 1.5%, and the pretest probability threshold for beginning treatment was determined to be 20.7%.

CONCLUSIONS

The potentially useful aspects of the history and physical examination were limited to a history of abdominal surgery, constipation, and the clinical examination findings of abnormal bowel sounds and abdominal distention. CT, MRI, and US are all adequate imaging modalities to make the diagnosis of SBO. Bedside US, which can be performed by EPs, had very good diagnostic accuracy and has the potential to play a larger role in the ED diagnosis of SBO. More ED-focused research into this area will be necessary to bring about this change.

Intra-abdominal adhesions in ultrasound. Part II: The morphology of changes

Despite their frequent appearance, intra-abdominal adhesions are rarely the subject of clinical studies and academic discussions. For many years the operators have been trying to reduce such unfavourable consequences of interventions in the abdominal structures. The aim of this article is to present the possibilities of intra-abdominal adhesion diagnostics by means of ultrasound imaging based on authors’ own experience and information included in pertinent literature. The anatomy and examination technique of the abdominal wall were discussed in Part I of the article. In order to evaluate intraperitoneal adhesions, one should use a convex transducer with the frequency of 3.5–6 MHz. The article provides numerous examples of US images presenting intra-abdominal adhesions, particularly those which appeared after surgical procedures. The significance of determining their localisation and extensiveness prior to a planned surgical treatment is emphasized. Four types of morphological changes in the ultrasound caused by intra-abdominal adhesions are distinguished and described: visceroperitoneal adhesions, intraperitoneal adhesions, adhesive obstructions as well as adhesions between the liver and abdominal wall with a special form of such changes, i.e. hepatic pseudotumour. Its ultrasound features are as follows:

The lesion is localised below the scar in the abdominal wall after their incision.

The lesion is localised in the abdominal part of the liver segments III, IV and V.

With the US beam focus precisely set, the lack of fascia – peritoneum complex may be noticed. An uneven liver outline or its ventral displacement appears.

A hepatic adhesion-related pseudotumour usually has indistinct margins, especially the posterior one, and, gradually, from top to bottom, loses its hypoechogenic nature.

In a respiration test, this liver fragment does not present the sliding movement – a neoplastic tumour rarely shows such an effect. The immobility of the liver is a permanent symptom of subdiaphragmatic abscess which needs to be included in the differentiation process.

In case of doubts, the suspicious liver area may be examined without the consideration of the scar in the abdominal wall.

In the differentiation of visceroperitoneal adhesions, firstly, one needs to exclude the peritoneum infiltration in the course of inflammation and neoplastic spreading, which may be very difficult in patients who have undergone a surgery. Pseudomyxoma peritonei constitutes a source of errors much more rarely.

Utility of CT in the diagnosis and management of small-bowel obstruction in children

BACKGROUND

CT is often used in the diagnosis and management of small-bowel obstruction in children.

OBJECTIVE

To determine sensitivity of CT in delineating presence, site and cause of small-bowel obstruction in children.

MATERIALS AND METHODS

We retrospectively reviewed the CT scans of 47 children with surgically proven small-bowel obstruction. We noted any findings of obstruction and the site and cause of obstruction. Presence, absence or equivocal findings of bowel obstruction on abdominal radiographs performed prior to CT were also noted. We reviewed patient charts for clinical details and surgical findings, including bowel resection. Statistical analysis was performed using Fisher exact test to determine which CT findings might predict bowel resection.

RESULTS

CT correctly diagnosed small-bowel obstruction in 43/47 (91.5%) cases. CT correctly indicated site of obstruction in 37/47 (78.7%) cases and cause of obstruction in 32/47 (68.1%) cases. Small-bowel feces sign was significantly associated with bowel resection at surgery (P = 0.0091). No other CT finding was predictive of bowel resection. Out of 41 children who had abdominal radiographs before CT, 29 (70.7%) showed unequivocal obstruction, six (14.6%) showed equivocal findings and six (14.6%) were unremarkable.

CONCLUSION

CT is highly sensitive in diagnosing small-bowel obstruction in children and is helpful in determining the presence of small-bowel obstruction in many clinically suspected cases with equivocal or normal plain radiographs. CT also helps to determine the site and cause of the obstruction with good sensitivity.

Crohn's disease imaging: a review

Crohn's disease is a chronic granulomatous inflammatory disease of the gastrointestinal tract, which can involve almost any segment from the mouth to the anus. Typically, Crohn's lesions attain segmental and asynchronous distribution with varying levels of seriousness, although the sites most frequently involved are the terminal ileum and the proximal colon. A single gold standard for the diagnosis of CD is not available and the diagnosis of CD is confirmed by clinical evaluation and a combination of endoscopic, histological, radiological, and/or biochemical investigations. In recent years, many studies have been performed to investigate the diagnostic potential of less invasive and more patient-friendly imaging modalities in the evaluation of Crohn's disease including conventional enteroclysis, ultrasonography, color-power Doppler, contrast-enhanced ultrasonography, multidetector CT enteroclysis, MRI enteroclysis, and 99mTc-HMPAO-labeled leukocyte scintigraphy. The potential diagnostic role of each imaging modality has to be considered in different clinical degrees of the disease, because there is no single imaging technique that allows a correct diagnosis and may be performed with similar results in every institution. The aim of this paper is to point out the advantages and limitations of the various imaging techniques in patients with suspected or proven Crohn's disease.

Diagnostic accuracies of MR enterography and CT enterography in symptomatic Crohn's disease

OBJECTIVE

In patients, with symptomatic Crohn's disease (CD), valid information about the presence or absence of small bowel disease activity and stenosis is clinically important. Such information supports decisions about medical or surgical therapy and can be obtained with MR enterography (MRE) or CT enterography (CTE).

MATERIALS AND METHODS

A total of 50 patients with symptomatic pre-existing CD and a demand for small bowel imaging to support changes in treatment strategy were included in this prospective and blinded study. MRE and CTE were performed on the same day in alternating order and subsequently compared with the gold standard: pre-defined lesions at ileoscopy (n = 30) or surgery with (n = 12) or without (n = 3) intra-operative enteroscopy.

RESULTS

A total of 35 patients had active small bowel CD (jejunum 0, ileum 1, (neo)-terminal ileum 34) and 20 had small bowel stenosis. The sensitivity and specificity of MRE for detection of small bowel CD was 74% and 80% compared to 83% and 70% with CTE (p ≥ 0.5). MRE and CTE detected small bowel stenosis with 55% and 70% sensitivities, respectively (p = 0.3) and 92% specificities.

CONCLUSIONS

MRE and CTE have comparable diagnostic accuracies for detection of small bowel CD and stenosis. In symptomatic patients with CD and high disease prevalence, positive predictive values are favorable but negative predictive values are low. Consequently, MRE and CTE can be relied upon, if a positive result is obtained whereas a negative enterography should be interpreted with caution.

Triphasic computed tomography enterography with polyethylene glycol to detect renal cell carcinoma metastases to the small bowel

Enteroclysis was first used to diagnose small bowel obstruction in 1996. However, nasojejunal intubation required during enteroclysis causes discomfort to the patient. Triphasic computed tomography (CT) enterography, a noninvasive procedure that does not require intubation, was found to be an efficient method to diagnose small bowel lesions. We describe our experience of using triphasic CT enterography with polyethylene glycol (PEG) for diagnosing renal cell carcinoma (RCC) metastases to the small intestine. RCC can metastasize to many organs and can cause variable clinical presentations. We report the case of a 56-year-old man with RCC who had psoas muscle involvement and lung metastasis. The patient presented with melena and intermittent abdominal pain. Two conventional CT and small bowel series examinations had shown no obstructive lesion in the small intestine. However, triphasic CT enterography with PEG detected two enhanced masses suggestive of small bowel metastasis. The patient underwent laparotomy and segmental resection of the jejunum with primary anastomosis. Histologic examination was compatible with RCC. This is the first report where RCC metastasis to the small bowel was diagnosed using triphasic CT enterography. Our study emphasizes the importance of triphasic CT enterography in cases of obscure gastrointestinal bleeding, especially in patients suspected of having small bowel metastasis.

Computed tomography enteroclysis: a review

Computed tomography (CT) enteroclysis is being performed routinely for evaluation of suspected small bowel diseases. The availability of multidetector CT scanners has further increased the diagnostic yield of enteroclysis. There is excellent depiction of small bowel wall pathology on CT enteroclysis especially with use of negative enteric contrast. We discuss the CT enteroclysis technique and procedure along with the imaging spectrum of some common small bowel pathologies.

Using multidetector-row CT for the diagnosis of afferent loop syndrome following gastroenterostomy reconstruction

PURPOSE

To assess the clinical manifestations and multidetector-row computed tomography (MDCT) findings of afferent loop syndrome (ALS) and to determine the role of MDCT on treatment decisions.

MATERIALS AND METHODS

From January 2004 to December 2008, 1,100 patients had undergone gastroenterostomy reconstruction in our institution. Of these, 22 (2%) patients were diagnosed as ALS after surgery that included Roux-en-Y gastroenterotomy (n=9), Billroth-II gastrojejunostomy (n=7), and Whipple's operation (n=6). Clinical manifestations and MDCT features of these patients were recorded and statistically analyzed. The presumed etiologies of obstruction shown on the MDCT were correlated with clinical information and confirmed by surgery or endoscopic biopsy.

RESULTS

The most common clinical symptom was acute abdominal pain, presenting in 18 patients (82%). We found that a fluid-filled C-shaped afferent loop in combination with valvulae conniventes projecting into the lumen was the most common MDCT features of ALS. Malignant causes of ALS, such as local recurrence and carcinomatosis, are the most common etiologies of obstruction. These etiologies and associated complications can be predicted 100% by MDCT.

CONCLUSION

Our results suggest that MDCT is a reliable modality for assessing the etiologies of ALS and guiding treatment decisions.

Bowel obstruction and hernia

Bowel obstruction and abdominal hernia are commonly observed in patients seeking emergency care for abdominal pain. This article discusses bowel obstruction, adynamic ileus, acute colonic pseudo-obstruction, and abdominal hernias, with particular emphasis on the management of patients in the emergency department (ED). Although the diagnostic approach to bowel obstruction often requires imaging, abdominal hernia may be identified in most circumstances by history and physical examination alone. Urgent surgical consultation is indicated when there is a concern for bowel ischemia, strangulation, or complete obstruction. This article reviews an ED-based approach to the patient presenting with symptoms of bowel obstruction or hernia.

Management of patients with malignant bowel obstruction and stage IV colorectal cancer

BACKGROUND

Malignant bowel obstruction (MBO), a serious problem in stage IV colorectal cancer (CRC) patients, remains poorly understood. Optimal management requires realistic assessment of treatment goals. This study's purpose is to characterize outcomes following palliative intervention for MBO in the setting of metastatic CRC.

STUDY DESIGN

Retrospective review of a prospective palliative database identified 141 patients undergoing surgical (OR; n = 96) or endoscopic (GI; n = 45) procedures for symptoms of MBO.

RESULTS

Median patient age was 58 years, median follow-up 7 months. Most (63%) had multiple sites of metastases. Computed tomography (CT) scan findings of carcinomatosis (p = 0.002), ascites (p = 0.05), and multifocal obstruction with carcinomatosis and ascites (p = 0.03) significantly predicted the need for percutaneous or open gastrostomy tube, or stoma. Procedure-associated morbidity for 81 patients with small bowel obstruction (SBO) was 37%; 7% developed an enterocutaneous fistula/anastomotic leak. Thirty-day mortality was 6%. Most (84%) patients were palliated successfully; some received additional chemotherapy (38%) or surgery (12%). Procedure-associated morbidity for 60 patients with large bowel obstruction (LBO) was 25%; 11 patients (18%) required other procedures for stent failure, with one death at 30 days. Symptom resolution was >97%. Patients with LBO had improved symptom resolution, shorter length of stay (LOS), and longer median survival than patients with SBO.

CONCLUSIONS

Patients with MBO and stage IV CRC were successfully palliated with GI or OR procedures. Patients with CT-identified ascites, carcinomatosis, or multifocal obstruction were least likely to benefit from OR procedures. CT plays an important role in preoperative planning. Sound clinical judgment and improved understanding are required for optimal management of MBO.

Current management of small bowel obstruction

SBO is a common disease with multiple causes. The most significant advances over the past several years have involved, first, decision-making techniques to promptly and accurately identify patients who will require exploration, and, second, the increasing use of laparoscopic techniques. "Complete" bowel obstruction is becoming an outdated term, as treatment algorithms use predictive models and oral contrast challenges to select patients for operation without recourse to the notion of "complete obstruction." Laparoscopic techniques are gaining acceptance as a primary modality in the treatment of SBO. Appropriate patient selection is necessary for success, but successful laparoscopic SBO management can reduce postoperative pain, minimize hospital stay, and may lead to fewer adhesions, possibly preventing further adhesive SBO. Strangulation obstruction is the major cause of morbidity and mortality in SBO. Although unrecognized strangulation obstructions remain, their incidence is decreasing with the new protocols in development. Future efforts should focus on incorporating predictive models into management with the goal of eliminating unrecognized strangulation obstructions. Further refinement of the predictive models incorporating outcomes of oral contrast challenges and molecular biomarker data may allow surgeons to reach this goal. In addition, the benefit of the elimination of interpractitioner variability conferred by standardized protocols will in itself improve patient outcomes.

Small bowel obstruction-who needs an operation? A multivariate prediction model

BACKGROUND

Proper management of small bowel obstruction (SBO) requires a methodology to prevent nontherapeutic laparotomy while minimizing the chance of overlooking strangulation obstruction causing intestinal ischemia. Our aim was to identify preoperative risk factors associated with strangulating SBO and to develop a model to predict the need for operative intervention in the presence of an SBO. Our hypothesis was that free intraperitoneal fluid on computed tomography (CT) is associated with the presence of bowel ischemia and need for exploration.

METHODS

We reviewed 100 consecutive patients with SBO, all of whom had undergone CT that was reviewed by a radiologist blinded to outcome. The need for operative management was confirmed retrospectively by four surgeons based on operative findings and the patient's clinical course.

RESULTS

Patients were divided into two groups: group 1, who required operative management on retrospective review, and group 2 who did not. Four patients who were treated nonoperatively had ischemia or died of malignant SBO and were then included in group 1; two patients who had a nontherapeutic exploration were included in group 2. On univariate analysis, the need for exploration (n = 48) was associated (p < 0.05) with a history of malignancy (29% vs. 12%), vomiting (85% vs. 63%), and CT findings of either free intraperitoneal fluid (67% vs. 31%), mesenteric edema (67% vs. 37%), mesenteric vascular engorgement (85% vs. 67%), small bowel wall thickening (44% vs. 25%) or absence of the "small bowel feces sign" (so-called fecalization) (10% vs. 29%). Ischemia (n = 11) was associated (p < 0.05 each) with peritonitis (36% vs. 1%), free intraperitoneal fluid (82% vs. 44%), serum lactate concentration (2.7 +/- 1.6 vs. 1.3 +/- 0.6 mmol/l), mesenteric edema (91% vs. 46%), closed loop obstruction (27% vs. 2%), pneumatosis intestinalis (18% vs. 0%), and portal venous gas (18% vs. 0%). On multivariate analysis, free intraperitoneal fluid [odds ratio (OR) 3.80, 95% confidence interval (CI) 1.5-9.9], mesenteric edema (OR 3.59, 95% CI 1.3-9.6), lack of the "small bowel feces sign" (OR 0.19, 95% CI 0.05-0.68), and a history of vomiting (OR 4.67, 95% CI 1.5-14.4) were independent predictors of the need for operative exploration (p < 0.05 each). The combination of vomiting, no "small bowel feces sign," free intraperitoneal fluid, and mesenteric edema had a sensitivity of 96%, and a positive predictive value of 90% (OR 16.4, 95% CI 3.6-75.4) for requiring exploration.

CONCLUSION

Clinical, laboratory, and radiographic factors should all be considered when making a decision about treatment of SBO. The four clinical features-intraperitoneal free fluid, mesenteric edema, lack of the "small bowel feces sign," history of vomiting-are predictive of requiring operative intervention during the patient's hospital stay and should be factored strongly into the decision-making algorithm for operative versus nonoperative treatment.

Development of a simple model for predicting need for surgery in patients who initially undergo conservative management for adhesive small bowel obstruction

BACKGROUND

Among patients with adhesive small bowel obstruction (ASBO) initially managed with a conservative strategy, predicting risk of operation is difficult.

METHODS

We investigated ASBO patients at 2 different periods to derive and validate a clinical prediction model for risk of operation.

RESULTS

One hundred fifty-four patients were enrolled into the derivation cohort and 96 into the validation cohort. Based on the derived scoring, including age > or =65 years, presence of ascites, and gastrointestinal drainage volume >500 mL on day 3, each patient was classified into 1 of 4 risk classes from low risk to high risk. When applied to the validation cohort, the positive predictive value (PPV) for operation in the high-risk class was 72%, while the negative predictive value (NPV) in the low-risk class was 100% with high sensitivity (100%) and specificity (96%).

CONCLUSIONS

The prediction model performs well for risk stratification of need for surgical intervention following conservative strategy among ASBO patients.

Role of computed tomography in the surgical management of patients with bowel obstruction secondary to recurrent ovarian carcinoma

BACKGROUND

The purpose of this study was to evaluate the potential role of preoperative computed tomography (CT) and clinical features for predicting the outcome of patients with bowel obstruction secondary to ovarian cancer.

MATERIALS AND METHODS

We identified a subpopulation of patients admitted to the Massachusetts General Hospital for bowel obstruction caused by recurrent ovarian cancer from January 1, 1995, to August 1, 2007. A retrospective review of 10 clinical features and 6 radiographic findings was performed. These findings were analyzed as variables with probable prognostic influence on survival and ability to predict successful palliation, defined as the ability to tolerate a regular or low-residue diet 60 days after discharge. Statistical significance was evaluated using the Fisher exact test. Univariate analysis was done by constructing probability curves according to the Kaplan-Meier method and comparing them by the log-rank test.

RESULTS

The study population consisted of 55 patients. Absence of carcinomatosis on CT scan and albumin > or = 3 g/dL were found to be able to predict successful palliation. Platinum resistance, albumin > or = 3 g/dL, and peritoneal carcinomatosis on CT scan were identified as variables with prognostic influence on survival in the univariate analysis. In the Cox regression analysis, only the absence of CT findings of carcinomatosis (P = .009) and albumin > or = 3 g/dL (P = .05) were independently associated with survival.

CONCLUSIONS

CT scan seems to be helpful in patients with a solitary site as the cause of bowel obstruction. All the patients in our study with this finding had a successful palliation. On the other hand, successful palliation is still feasible in the presence of peritoneal carcinomatosis on CT scan; therefore, this finding alone should not be the reason to avoid surgery in well-selected patients.

MR enteroclysis in the diagnosis of small-bowel neoplasms

PURPOSE

To evaluate the diagnostic accuracy and interobserver variance of magnetic resonance (MR) enteroclysis in the diagnosis of small-bowel neoplasms, with small-bowel endoscopy, surgery, histopathologic analysis, and follow-up serving as standards of reference, and to identify MR enteroclysis characteristics capable of enabling discrimination between benign and malignant small-bowel neoplasms.

MATERIALS AND METHODS

This study was performed in accordance with the guidelines of the institutional review board, and the requirement for informed consent was waived. MR enteroclysis studies of 91 patients (43 women, 48 men; age range, 18-83 years) were retrospectively evaluated by two radiologists blinded to clinical details. Only studies explicitly performed to investigate or exclude the presence of small-bowel neoplasms were included. Radiologic findings were compared with findings of double-balloon endoscopy (n = 45), surgery (n = 18), esophagogastroduodenoscopy (n = 3), ileocolonoscopy (n = 2), autopsy (n = 2), and clinical follow-up for more than 18 months (n = 21). Efficacy parameters were calculated with 95% confidence intervals. Tumor characteristics were compared with the Student t test and the Fisher exact test.

RESULTS

Readers 1 and 2 interpreted 31 and 33 studies, respectively, as depicting a small-bowel neoplasm and 19 and 17 studies, respectively, as depicting small-bowel malignancy. In 32 patients, the presence of small-bowel neoplasm was confirmed. In 19 of these patients, the neoplasm was malignant. Sensitivity and specificity in the diagnosis of small-bowel neoplasms was 0.91 and 0.95, respectively, for reader 1 and 0.94 and 0.97, respectively, for reader 2; the kappa value was 0.95. Factors associated with malignancy were the presence of longer solitary nonpedunculated lesions, mesenteric fat infiltration, and enlarged mesenteric lymph nodes.

CONCLUSION

Eighty-six of 91 studies were correctly interpreted, resulting in an overall diagnostic accuracy of 0.95 for MR enteroclysis in the detection of small-bowel neoplasms.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.09090828/-/DC1.

A rare case of adult primary jejunal volvulus

Jejunal volvulus is a rare and life threatening presentation of intestinal ischaemia. Clinical features, laboratory investigations and plain abdominal films are non-specific and so computed tomography (CT) scanning is useful in reaching a timely diagnosis. Rapid recourse to surgical intervention is typical and life saving. We report a rare case of primary jejunal volvulus which, after diagnosis on emergency CT scanning, was successfully treated by laparotomy and resection of infarcted bowel.

Intestinal duplication in an adult patient diagnosed by multidetector computed tomography enteroclysis: report of a case

This study reports a case of small-bowel duplication, a rare congenital malformation, in an adult with abdominal pain and sub-obstruction signs. CT enteroclysis allowed the diagnosis that conventional imaging failed to demonstrate and it confirmed itself the most accurate exam in small-bowel disease diagnosis. This is the first report of a small-bowel duplication diagnosed by CT enteroclysis.

Imaging patients with acute abdominal pain

Acute abdominal pain may be caused by a myriad of diagnoses, including acute appendicitis, diverticulitis, and cholecystitis. Imaging plays an important role in the treatment management of patients because clinical evaluation results can be inaccurate. Performing computed tomography (CT) is most important because it facilitates an accurate and reproducible diagnosis in urgent conditions. Also, CT findings have been demonstrated to have a marked effect on the management of acute abdominal pain. The cost-effectiveness of CT in the setting of acute appendicitis was studied, and CT proved to be cost-effective. CT can therefore be considered the primary technique for the diagnosis of acute abdominal pain, except in patients clinically suspected of having acute cholecystitis. In these patients, ultrasonography (US) is the primary imaging technique of choice. When costs and ionizing radiation exposure are primary concerns, a possible strategy is to perform US as the initial technique in all patients with acute abdominal pain, with CT performed in all cases of nondiagnostic US. The use of conventional radiography has been surpassed; this examination has only a possible role in the setting of bowel obstruction. However, CT is more accurate and more informative in this setting as well. In cases of bowel perforation, CT is the most sensitive technique for depicting free intraperitoneal air and is valuable for determining the cause of the perforation. Imaging is less useful in cases of bowel ischemia, although some CT signs are highly specific. Magnetic resonance (MR) imaging is a promising alternative to CT in the evaluation of acute abdominal pain and does not involve the use of ionizing radiation exposure. However, data on the use of MR imaging for this indication are still sparse.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/content/253/1/31/suppl/DC1.

Self expanding wall stents in malignant colorectal cancer: is complete obstruction a contraindication to stent placement?

OBJECTIVE

Technical failures have previously been associated with complete clinical obstruction and complete block to the retrograde flow of gastrograffin is considered by some to be a contraindication to the procedure. We report on the technical and clinical success rates of self-expanding metallic stents (SEMS) in both complete and incomplete obstruction in a prospective series of malignant colorectal obstructions.

METHOD

A prospective study of all patients undergoing attempted palliative and bridge to surgery SEMS placement for malignant colorectal obstruction over a 7-year period (April 1999-October 2006) was undertaken.

RESULTS

Seventy-two patients (49 males) with a mean age of 71 years (range 49-98) were included. Technical success was achieved in 27 of 32 patients (84%) with complete obstruction and 33 of 36 patients (92%) with incomplete obstruction, P < 0.46, Fishers exact test. Clinical success was achieved in 17 of 26 patients (65%) with complete obstruction and 24 of 33 patients (73%) with incomplete obstruction, P < 0.58, Fishers exact test. Although placed correctly in 89% cases, relief of symptoms occurred in only 71%, P = 0.002, matched pairs test. There were two colonic perforations in the series with one procedure related death.

CONCLUSION

Placement of SEMS for obstructing colorectal cancer is technically successful in a high proportion of cases. Complete radiological obstruction is not a contraindication to stent placement. The relief of obstructive symptoms following successful placement of a wall stent is less predictable.

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.

Partial small bowel obstruction: clinical issues and recent technical advances

Mechanical small bowel obstruction (SBO) remains a common clinical problem despite ever-increasing medical and surgical advances. The predominant etiology continues to be postoperative adhesions, accounting for approximately two-thirds of all obstructive events. As opposed to high-grade or complete small bowel obstruction where the clinical and radiographic findings are typically more diagnostic and the treatment plan more defined, partial SBO represents a subgroup, where the evaluation is more arduous, the diagnosis more elusive, and the management less defined. Operative and nonoperative approaches to treatment are successful and are based on the etiology and clinical status of the patient. A paradox remains, however, treating a predominantly surgically induced condition with repeated operations. Several advances in the treatment and prevention of SBO have become practice in past decade. This article reviews the clinical issues and technical advances of this challenging condition.

Cancer emergencies: the acute abdomen

The most common complaints among patients with cancer who present to the emergency department are related to the gastrointestinal system, and 40% of these patients complain of abdominal pain. These presentations can stem from the underlying malignancy itself, treatment directed toward the disease, or the full range of pathologies present in a healthy population. Immunosuppression may blunt many of the findings one expects in a healthy population of patients, thus rendering the clinical exam less reliable in many patients with cancer. Moreover, the degree of immunosuppression shapes both the types of pathologies the clinician should consider and the rate at which the disease may progress. Understanding the limitations of physical examination, pathophysiology of disease, and the methods by which these diagnoses are established is of critical importance in this population. This article focuses specifically on patients with cancer who present with an acute abdomen, and it discusses how a concurrent malignancy can shape the differential diagnosis in these cases.