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

Distortionless, free-breathing, and respiratory resolved 3D diffusion weighted imaging of the abdomen

PURPOSE

Abdominal imaging is frequently performed with breath holds or respiratory triggering to reduce the effects of respiratory motion. Diffusion weighted sequences provide a useful clinical contrast but have prolonged scan times due to low signal-to-noise ratio (SNR), and cannot be completed in a single breath hold. Echo-planar imaging (EPI) is the most commonly used trajectory for diffusion weighted imaging but it is susceptible to off-resonance artifacts. A respiratory resolved, three-dimensional (3D) diffusion prepared sequence that obtains distortionless diffusion weighted images during free-breathing is presented. Techniques to address the myriad of challenges including: 3D shot-to-shot phase correction, respiratory binning, diffusion encoding during free-breathing, and robustness to off-resonance are described.

METHODS

A twice-refocused, M1-nulled diffusion preparation was combined with an RF-spoiled gradient echo readout and respiratory resolved reconstruction to obtain free-breathing diffusion weighted images in the abdomen. Cartesian sampling permits a sampling density that enables 3D shot-to-shot phase navigation and reduction of transient fat artifacts. Theoretical properties of a region-based shot rejection are described. The region-based shot rejection method was evaluated with free-breathing (normal and exaggerated breathing), and respiratory triggering. The proposed sequence was compared in vivo with multishot DW-EPI.

RESULTS

The proposed sequence exhibits no evident distortion in vivo when compared to multishot DW-EPI, robustness to B0 and B1 field inhomogeneities, and robustness to motion from different respiratory patterns.

CONCLUSION

Acquisition of distortionless, diffusion weighted images is feasible during free-breathing with a b-value of 500 s/mm2, scan time of 6 min, and a clinically viable reconstruction time.

Neutrophil to lymphocyte ratio predicts bowel ischemia in non-strangulated adhesive small bowel occlusions: a retrospective analysis from an acute care surgical service

BACKGROUND

Adhesive small bowel obstruction (ASBO) is a leading cause of hospitalization in emergency surgery. The occurrence of bowel ischemia significantly increases the morbidity and mortality rates associated with this condition. Current clinical, biochemical and radiological parameters have poor predictive value for bowel ischemia. This study is designed to ascertain predictive elements for the progression to bowel ischemia in patients diagnosed with non-strangulated ASBO who are initially managed through conservative therapeutic approaches.

METHODS

The study was based on the previously collected medical records of 128 patients admitted to the Department of Acute Care Surgery of Padua General Hospital, from August 2020 to April 2023, with a diagnosis of non-strangulated adhesive small bowel obstruction, who were then operated for failure of conservative treatment. The presence or absence of bowel ischemia was used to distinguish the two populations. Clinical, biochemical and radiological data were used to verify whether there is a correlation with the detection of bowel ischemia.

RESULTS

We found that a Neutrophil-Lymphocyte ratio (NLR) > 6.8 (OR 2.9; 95% CI 1.41-6.21), the presence of mesenteric haziness (OR 2.56; 95% CI 1.11-5.88), decreased wall enhancement (OR 4.3; 95% CI 3.34-10.9) and free abdominal fluid (OR 2.64; 95% CI 1.08-6.16) were significantly associated with bowel ischemia at univariate analysis. At the multivariate logistic regression analysis, only NLR > 6.8 (OR 5.9; 95% CI 2.2-18.6) remained independent predictive factor for small bowel ischemia in non-strangulated adhesive small bowel obstruction, with 78% sensitivity and 65% specificity.

CONCLUSIONS

NLR is a straightforward and reproducible parameter to predict bowel ischemia in cases of non-strangulated adhesive small bowel obstruction. Employing NLR during reevaluation of patients with this condition, who were initially treated conservatively, can help the acute care surgeons in the early prediction of bowel ischemia onset.

Exploring the diagnostic accuracy and applicability of the Gugging Swallowing Screen in children with feeding and/or swallowing disorders

BACKGROUND

The Gugging Swallowing Screen (GUSS) is a bedside dysphagia screening tool that has been designed to determine the risk of aspiration in acute stroke patients. There is no evidence in the literature for the GUSS for the pediatric population. The present study aimed to determine the diagnostic accuracy of GUSS as a screening tool in the Greek language for children with dysphagia.

METHODS

Eighty-Greek-Cypriot children aged 3-12 years who had dysphagia participated in this retrospective study. The translated into Greek GUSS was administered twice (pre- and post-therapy) to each patient throughout 24 sessions of dysphagia therapy.

KEY RESULTS

The GUSS showed a high internal consistency (Cronbach's α = 0.826), good test-retest reliability (rs = 0.767), convergent validity compared to the Greek Pediatric Eating Assessment tool-10 (PEDI-EAT-10) total score (rs = -0.365), and inter-rater reliability (κ = 0.863). A total cutoff points equal to 13.00 was also calculated. Aspiration was identified by the GUSS with low sensitivity and high specificity (PPV 100%, NPV 57%, LR+ NA, LR- 0.79); dysphagia/penetration was identified with high sensitivity and low specificity (PPV 33%, NPV 100%, LR+ 0.102, LR- NA).

CONCLUSIONS & INFERENCES

The pediatric version of GUSS has been found to be a valuable tool in identifying the risk of aspiration as that of adults. It proved to be used as a good screening guide for selecting and confirming the existence of dysphagia from instrumental assessments. This is the first study of the pediatric version of GUSS, and future studies on this topic are needed.

CLINICAL AND SURGICAL DILEMMAS IN OCTOGENARIAN PATIENTS WITH SMALL BOWEL OBSTRUCTION

BACKGROUND

Small bowel obstruction (SBO) is a major problem in emergencies. Comorbidities increase morbimortality, which is reflected in higher costs. There is a lack of Latin American evidence comparing the differences in postoperative results and costs associated with SBO management.

AIMS

To compare the risk of surgical morbimortality and costs of SBO surgery treatment in patients older and younger than 80 years.

METHODS

Retrospective analysis of patients diagnosed with SBO at the University of Chile Clinic Hospital from January 2014 to December 2017. Patients with any medical treatment were excluded. Parametric statistics were used (a 5% error was considered statistically significant, with a 95% confidence interval).

RESULTS

A total of 218 patients were included, of which 18.8% aged 80 years and older. There were no differences in comorbidities between octogenarians and non-octogenarians. The most frequent etiologies were adhesions, hernias, and tumors. In octogenarian patients, there were significantly more complications (46.3 vs. 24.3%, p=0.007, p<0.050). There were no statistically significant differences in terms of surgical complications: 9.6% in <80 years and 14.6% in octogenarians (p=0.390, p>0.050). In medical complications, a statistically significant difference was evidenced with 22.5% in <80 years vs 39.0% in octogenarians (p=0.040, p<0.050). There were 20 reoperated patients: 30% octogenarians and 70% non-octogenarians without statistically significant differences (p=0.220, p>0.050). Regarding hospital stay, the average was significantly higher in octogenarians (17.4 vs. 11.0 days; p=0.005, p<0.050), and so were the costs, being USD 9,555 vs. USD 4,214 (p=0.013, p<0.050).

CONCLUSIONS

Patients aged 80 years and older with surgical SBO treatment have a higher risk of medical complications, length of hospital stay, and associated costs compared to those younger.

CT prognostic signs of postoperative complications in emergency surgery for acute obstructive colonic cancer

PURPOSE

To identify CT prognostic signs of poor outcomes in acute obstructive colonic cancer (AOCC).

METHODS

Demographic, clinical, laboratory, radiological and surgical data of 65 consecutive patients with AOCC who underwent emergency surgery were analyzed. CT exams were reviewed to assess diameters of cecum, ascending, transverse, descending, and sigmoid proximal to the tumor; colon segments' CD/L1-VD ratios, continence of the ileocecal valve, small bowel overdistension, presence of small bowel feces sign and cecal pneumatosis. Post Operative complications (PO), according to the Clavien-Dindo classification, were analyzed.

RESULTS

Gender, age and location of the tumor were not predictive factors of complications. Among laboratory exams, CRP was the most important predictive value of PO (OR 8.23). A cecum distension ≥ 9 cm represented the critical diameter beyond which perforation and cecal necrosis were found at surgery. Cecal pneumatosis at CT was correlated with cecal necrosis at surgery in < 50% of patients. Pre-operative transverse colon CD/L1-VD ratio ≥ 1.43 and descending colon CD/L1-VD ratio ≥ 1.31 were associated with the development of PO (grade ≥ III-V). PO (grade ≥ III-V) occurred in 18/65 patients.

CONCLUSION

Postoperative complications in emergency surgery of AOCC were not related to the age, sex and tumor's location. Preoperative PCR values (≥ 2.17) predict the development of postoperative complications. CT resulted a valid diagnostic tool to identify patients at higher risk of complications: a CD/L1-VD ratios with cut-off values of 1.43 (transverse) and 1.31 (descending) predicted major complications (grade ≥ III-V) and a cecum distension ≥ 9 cm represented the critical diameter beyond which perforation occurred in > 84% of patients.

Prediction of bowel necrosis by reduced bowel wall enhancement in closed-loop small bowel obstruction: Quantitative methods

PURPOSE

To assess diagnostic performance and reproducibility of reduced bowel wall enhancement evaluated by quantitative methods using CT to identify bowel necrosis among closed-loop small bowel obstruction (CL-SBO) patients.

METHODS

This retrospective single-center study included patients who diagnosed with CL-SBO caused by adhesion or internal hernia during January 2016 and May 2022. Patients were divided into necrotic group (n = 41) and non-necrotic group (n = 67) according to surgical exploration and postoperative pathology. Two doctors independently measured the attenuation of bowel wall and consensus was reached through panel discussion with a third gastrointestinal radiologist. Reduced bowel wall enhancement was assessed by four quantitative methods. Univariate analyses were used to evaluate the association between each method and bowel necrosis, and kappa/intraclass correlation coefficient values were used to assess interobserver agreement. Diagnostic performance parameters were calculated for each method.

RESULTS

Reduced bowel wall enhancement in arterial phase (OR 8.98, P < 0.0001), reduced bowel wall enhancement in portal phase (OR 16.84, P < 0.001), adjusted reduced bowel wall enhancement in arterial phase (OR 29.48, P < 0.001), adjusted reduced bowel wall enhancement in portal phase (OR 145.69, P < 0.001) were significantly associated with bowel necrosis. Adjusted reduced bowel wall enhancement in portal phase had the best diagnostic performance (AUC: 0.92; Youden index: 0.84; specificity: 94.03 %) and interobserver agreement (kappa value of 0.59-0.73) to predict bowel necrosis.

CONCLUSION

When assessing reduced bowel enhancement to predict bowel necrosis among CL-SBO patients, using unenhanced CT images and proximal dilated loop as standard references in portal phase is the most accurate quantitative method among those tested.

[Emergency diagnoses in the gastrointestinal tract]

Gastrointestinal emergencies are a frequent reason for presentation in the emergency department and involve patients of all ages. The patients must undergo an immediate cross-sectional imaging as in many cases the underlying pathology is a life-threatening condition, which often needs surgical or in some cases also interventional radiological treatment. In this overview, the most important differential diagnoses and their characteristics on cross-sectional imaging are presented.

Pearls and Pitfalls of Imaging Small Bowel Obstruction

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

Towards an EKG for SBO: A Neural Network for Detection and Characterization of Bowel Obstruction on CT

A neural network was developed to detect and characterize bowel obstruction, a common cause of acute abdominal pain. In this retrospective study, 202 CT scans of 165 patients with bowel obstruction from March to June 2022 were included and partitioned into training and test data sets. A multi-channel neural network was trained to segment the gastrointestinal tract, and to predict the diameter and the longitudinal position ("longitude") along the gastrointestinal tract using a novel embedding. Its performance was compared to manual segmentations using the Dice score, and to manual measurements of the diameter and longitude using intraclass correlation coefficients (ICC). ROC curves as well as sensitivity and specificity were calculated for diameters above a clinical threshold for obstruction, and for longitudes corresponding to small bowel. In the test data set, Dice score for segmentation of the gastrointestinal tract was 78 ± 8%. ICC between measured and predicted diameters was 0.72, indicating moderate agreement. ICC between measured and predicted longitude was 0.85, indicating good agreement. AUROC was 0.90 for detection of dilated bowel, and was 0.95 and 0.90 for differentiation of the proximal and distal gastrointestinal tract respectively. Overall sensitivity and specificity for dilated small bowel were 0.83 and 0.90. Since obstruction is diagnosed based on the diameter and longitude of the bowel, this neural network and embedding may enable detection and characterization of this important disease on CT.

Increased Attenuation of Intestinal Contents at CT Indicates Bowel Necrosis in Closed-Loop Small Bowel Obstruction

Background Preoperative recognition of irreversible bowel necrosis is important, as it provides valuable guidance for surgical strategy selection but also may inform perioperative risk assessment and communication. Few studies have focused on the association between CT signs and bowel necrosis. Purpose To assess the diagnostic accuracy of CT signs to predict bowel necrosis in patients with closed-loop small bowel obstruction (CL-SBO). Materials and Methods This retrospective single-center study included patients who were surgically confirmed to have CL-SBO caused by adhesion or internal hernia between January 2016 and May 2022. Necrosis was determined based on surgical exploration and postoperative pathologic examination. Two radiologists independently reviewed CT signs by both subjective visual assessment and objective measurement. Disagreements were resolved in consensus with a third gastrointestinal radiologist. Univariable and multivariable analyses were used to assess the association between CT signs and bowel necrosis, and Cohen κ was used to assess interobserver agreement. Sensitivity and specificity were calculated for each CT sign. Results This study included 145 patients: 61 (42.1%) in the necrotic group (median age, 62 years [IQR, 51-71.5 years]; 37 [60.7%] women) and 84 (57.9%) in the nonnecrotic group (median age, 61.5 years [IQR, 51-68.8 years]; 51 [60.7%] women). Univariable analysis and multivariable analysis showed that increased attenuation of intestinal contents and increased attenuation of intestinal wall were independent predictors for bowel necrosis (odds ratio = 45.3 and 15.1; P = .001 and P < .001, respectively). Increased attenuation of intestinal contents and increased attenuation of intestinal wall had similar sensitivity (64% and 67%, respectively) and specificity (99% and 92%, respectively) for predicting bowel necrosis. However, interobserver agreement was better for assessing the contents than the wall (κ = 0.84 and 0.59, respectively). Conclusion Increased attenuation of intestinal contents was a highly specific CT sign with good reproducibility to predict bowel necrosis in CL-SBO. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Taourel and Zins in this issue.

Point of Care Abdominal Ultrasound

Abdominal pain is a common emergency department complaint, and point-of-care ultrasound (POCUS) of the abdomen is increasingly being utilized to evaluate clinical manifestations. It aids in accurate diagnoses and assists in procedures, particularly in emergency and critical care settings. Imaging is often required to confirm the etiology of abdominal pain. POCUS provides the benefit of avoiding radiation exposure and enables quicker diagnosis compared to computed tomography scans. There is growing evidence of the diagnostic accuracy for numerous abdominal POCUS applications, including appendicitis, intussusception, diverticulitis, gastric ultrasound and contrast-enhanced ultrasound.

Iodine density mapping for the diagnosis of acute bowel ischemia using fast kV-switching dual-energy CT

PURPOSE

To evaluate the diagnostic capabilities of a supplementary color ramped iodine density map compared to virtual monoenergetic images (VMIs) at 74 keV in the diagnosis of acute bowel ischemia (ABI).

METHODS

Data for this study were prospectively gathered and retrospectively evaluated. Patients referred to the Department of Diagnostic Radiology between October 2020 and August 2022 on the suspicion of ABI and underwent surgery < 12 h following fast kV-switching venous phase abdominal dual-energy CT (DECT) were consecutively included. Images were evaluated by two board-certified radiologists and two radiology residents. First round included only 74 keV VMIs resembling conventional 120 kVp images, and the second round included a supplementary iodine density map. Readers were asked to register presence of ABI as well as their confidence in their diagnosis based on a 5-point Likert scale. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each observer with the surgical findings as the gold-standard. McNemar's and Wilcoxon signed-rank test were used to compare registrations and diagnostic confidence across assessment rounds.

RESULTS

A total of 29 patients resulting in 31 DECT scans were included. Fourteen cases of ischemic/necrotic bowel were reported following surgery. Sensitivity and NPV were decreased with the use of supplementary iodine map images compared to 120 kVp-like images without supplementary iodine map images for three of four observers (round 1 range: 71.4-92.9% and 78.0-94.8%; round 2 range: 57.1-78.6% and 70.1-83.3%, respectively), while specificity and PPV were increased for three of four observers (round 1 range: 64.7-94.1% and 67.4-93.1%; round 2 range: 88.2-94.1% and 73.8-91.1%, respectively). However, no significant difference in ABI diagnosis or diagnostic confidence was found (p-value range: 0.07-1.00 and 0.23-0.58, respectively).

CONCLUSION

No significant difference for the diagnosis of ABI was found using supplementary iodine mapping. Our study may suggest a trend of increased specificity and decreased sensitivity, hence, the use of supplementary iodine mapping should be carefully considered.

Meckel's diverticulum: analysis of 27 cases in an adult population

Background

Meckel's diverticulum is a rare congenital pathology among newborns. Nevertheless, it is an uncommon abdominal pathology in the adult population. Therefore, we aim to provide a detailed account of our surgical approach in treating 27 cases of Meckel's diverticulum.

Methods

This study is a cross-sectional analysis that utilized a database with prospectively collected data from 2004 to 2022. All patients under the age of 18 were excluded from the population. We described the population's demographic characteristics, symptoms, anatomopathological study, surgical technique, complications, morbidity, and mortality. A subgroup analysis was performed between the symptomatic and asymptomatic patients.

Results

A total of 27 patients who underwent surgical resection for a posteriorly diagnosed Meckel's diverticulum were included. The male population accounted for 81.4% (n = 22) of the sample size. The symptomatic group consisted of 18 male and four female patients. Abdominal pain was the predominant symptom in 85% of the patients. Out of the 22 symptomatic patients, only 9% had a positive perioperative diagnosis of Meckel's diverticulum. All 27 patients with diverticulum diagnosis received the resection through diverticulectomy (n = 6), small bowel resection with end-to-end anastomosis (n = 6), and small bowel resection with lateral to lateral anastomosis (n = 15). The mean distance between the diverticulum and the ileocecal valve was 63.4 cm. The symptomatic group had an average diverticulum length of 3.54 cm, with an average base width of 2.47 cm. In the other group, the values were 2.75 and 1.61 cm. The average length of hospital stay in the symptomatic group was 7.3 days.

Conclusions

Meckel's diverticulum is a rare pathology in the adult population. Its presentation varies from asymptomatic to symptomatic patients, and surgery is the cornerstone treatment for this pathology.

Evaluation of Abdominal Emergencies

Early primary assessment and abdominal examination can often be enough to triage the patient with abdominal pain into those with less severe underlying pathologic condition from those with more acute findings. A focused history of the patient can then allow the clinician to develop their differential diagnosis. Once the differential diagnoses are determined, diagnostic imaging and laboratory findings can help confirm the diagnosis and allow for expeditious treatment and intervention.

Does the use of computed tomography scenogram alone enable diagnosis in cases of bowel obstruction?

BACKGROUND

Ileus is a pathological condition of the abdomen that presents as a medical emergency. It is characterized by potential complications such as perforation and ischemia, which can lead to significant morbidity and mortality if not promptly addressed. The successful management of ileus relies heavily on the timely and precise identification of the condition. While conventional radiography (CR) is commonly used as the primary diagnostic tool, its accuracy in identifying obstructions ranges from 46% to 80%. Furthermore, the diagnostic accuracy of identifying the location and etiology of intestinal obstruction by CR is limited, therefore making computed tomography (CT) the ideal imaging modality in this regard.

AIM

To determine the presence of acute bowel obstruction (BO) on abdominal CT scenogram images and the accuracy of determining its possible location, taking into account the experience of the observers.

METHODS

A retrospective screening was conducted on an ensemble of 46 individuals who presented to the emergency department between January 2021 and January 2022 with severe abdominal pain and were subsequently monitored for suspected ileus. The abdominal CT scans of these patients were assessed by three radiologists with varying levels of experience (1, 3, and 10 years) at different intervals (1 mo apart). The evaluation focused on determining the presence or absence of BO, as well as identifying the potential location of the obstruction (small bowel or large bowel). The study employed Kappa statistics to assess inter-observer variances, while the McNamer test was used to evaluate obstruction and segmentation discrepancies between observations. A significance level of P < 0.05 was determined to indicate statistical significance.

RESULTS

Out of the total sample size of 46 patients, 15 individuals (32.6%) were identified as female, while the remaining 31 individuals (67.4%) were identified as male. The ultimate diagnosis of 42 instances (91.3%) indicated ileus resulting from mechanical obstruction (MO). Among these patients, 14 (33%) experienced obstruction in the large bowel (LB), while 28 (66%) experienced obstruction in the small bowel (SB). The initial evaluation yielded sensitivity rates of 76.19%, 83.31%, and 83.33%, and diagnostic accuracy rates of 69.56%, 76.08%, and 80.43% for the detection of BO among the three observers. The initial study revealed that the average sensitivity of three observers in detecting the presence of ileus caused by MO was 80.94%, while the diagnostic accuracy was 75.35%. Based on the first evaluation, the senior observer demonstrated the highest sensitivity (85.71%), negative predictive value (92.60%), and diagnostic accuracy (80.43%) when accurately estimating the thick and thin segmentation, as per the final diagnosis. There was no statistically significant disparity observed in the sensitivities pertaining to the identification of ileus during the second assessment, as well as the precise determination of the segment level inside the LB or SB, when comparing the second and third observers. Nevertheless, although there was no statistically significant alteration in the detection rate of ileus by the first observer, there was a notable rise in the accuracy rate of segment estimating (73.91%). The senior assessor had a higher level of accuracy in assessing the existence of ileus and segmentation compared to the other evaluators in both evaluations.

CONCLUSION

The findings of our study indicate that the sensitivity and accuracy rates of abdominal CT scenogram scans in diagnosing acute MOs are similar to or greater than those of CR. Additionally, the study revealed that radiologists with more experience demonstrated a higher likelihood of accurately predicting the existence and potential localization of MO compared to their less experienced counterparts.

Accurately evaluating for a small bowel obstruction using an abdominal radiograph, by a new method: The Bowel-Spine Ratio

INTRODUCTION

A well-established method does not exist to rule out a small bowel obstruction using an abdominal xray series with significant accuracy. The hypothesis of the study is that the ratio of an average small bowel diameter to lumbar spine diameter over 0.5 is most likely a small bowel obstruction.

METHODS

An x-ray abdominal series measurement technique was applied to 41 subjects with a chief complaint of "abdominal pain" as part of a randomized retrospective case review to predict an obstruction v. non obstruction. A total number of 81 abdominal pain subjects with a mean age of 46.7 years were selected with 40 excluded due to normal small bowel gas pattern. The subject's medical information was unknown to the authors when reading their images. The measurement technique involved averaging the largest and smallest small bowel short axis diameters with comparison to the lowest clearly visible lumbar body width. The subjects' medical course as described in the medical chart or subsequent computed tomography scans were used as the referencing standard to determine presence of obstruction vs non-obstruction.

RESULTS

This method, called the Bowel-Spine Ratio (BSR), resulted in a sensitivity of 0.882 (0.622-0.979; 95% CI), specificity of 0.957 (0.760-0.998; 95% CI), accuracy of 94.7% (80.9%-99.1%; 95% CI) and a positive likelihood ratio of 21 for predicting a small bowel obstruction.

CONCLUSION

The abdominal series Bowel-Spine Ratio is a simple yet effective technique to screen for a small bowel obstruction using limited resources and to avoid unnecessary computed tomography scans with the potential to reduce health care costs.

IMPLICATIONS FOR PRACTICE

Clinicians could have increased confidence in utilizing abdominal radiographs to evaluate for small bowel obstruction.

Visual Image Annotation for Bowel Obstruction: Repeatability and Agreement with Manual Annotation and Neural Networks

Bowel obstruction is a common cause of acute abdominal pain. The development of algorithms for automated detection and characterization of bowel obstruction on CT has been limited by the effort required for manual annotation. Visual image annotation with an eye tracking device may mitigate that limitation. The purpose of this study is to assess the agreement between visual and manual annotations for bowel segmentation and diameter measurement, and to assess agreement with convolutional neural networks (CNNs) trained using that data. Sixty CT scans of 50 patients with bowel obstruction from March to June 2022 were retrospectively included and partitioned into training and test data sets. An eye tracking device was used to record 3-dimensional coordinates within the scans, while a radiologist cast their gaze at the centerline of the bowel, and adjusted the size of a superimposed ROI to approximate the diameter of the bowel. For each scan, 59.4 ± 15.1 segments, 847.9 ± 228.1 gaze locations, and 5.8 ± 1.2 m of bowel were recorded. 2d and 3d CNNs were trained using this data to predict bowel segmentation and diameter maps from the CT scans. For comparisons between two repetitions of visual annotation, CNN predictions, and manual annotations, Dice scores for bowel segmentation ranged from 0.69 ± 0.17 to 0.81 ± 0.04 and intraclass correlations [95% CI] for diameter measurement ranged from 0.672 [0.490-0.782] to 0.940 [0.933-0.947]. Thus, visual image annotation is a promising technique for training CNNs to perform bowel segmentation and diameter measurement in CT scans of patients with bowel obstruction.

Complex Surgical Intervention for Small Bowel Obstruction Secondary to Metastatic Colorectal Cancer

Small bowel obstruction (SBO) refers to the inability of contents to pass through the lumen of the small intestine. This is a common surgical emergency in the United States. Although intra-abdominal adhesions are the predominant cause, SBO can occur secondarily to various etiologies, be it one cause or several. Management of SBO secondary to adhesions and metastasized rectal adenocarcinoma, complicated by pulmonary, hepatic, and ureteral disease, highlights the criticality of a multidisciplinary approach. We present a case of a 59-year-old male with SBO secondary to rectal adenocarcinoma. Treatment included surgical resection, acute stabilization, referral for outpatient surgical follow-up, and oncologic management.

Small bowel transmural necrosis secondary to acute mesenteric ischemia and strangulated obstruction: CT findings of 49 patients

Rationale and objectives

Transmural bowel necrosis (TBN) is an uncommon surgical emergency that represents an endpoint of occlusive acute mesenteric ischemia (AMI), nonocclusive AMI and small bowel obstruction (SBO). According to limited evidence, each etiology of TBN might demonstrate a different CT finding. This investigation aimed to 1) identify overall CT findings of TBN, and 2) compare CT findings of TBN in each etiology.

Materials and methods

Forty-nine consecutive adults (mean age, 64.6 years; 26 men) with occlusive AMI, nonocclusive AMI or SBO, and pathologically proven TBN were enrolled. All had a CT scan within 24 h before surgery. Clinical information was compiled from medical records. CT examinations were re-reviewed by two radiologists with disagreements resolved by the third radiologist. Data were analyzed and compared.

Results

Transmural bowel necrosis were secondary to arterial AMI, venous AMI, combined arterial and venous AMI, nonocclusive AMI, and SBO in 6, 5, 2, 10, and 26 patients, respectively. The CT findings were ascites (93.9%), abnormal wall enhancement (91.8%), bowel dilatation (89.8%), mesenteric fat stranding (89.8%), abnormal wall thickness (71.5%), pneumatosis (46.9%) and intrinsic hyperattenuation of bowel walls (22.5%). Portovenous gas, mesenteric venous gas, and pneumoperitoneum were present in 4 patients (8.2%). Bowel wall thickness was the only CT findings that showed a statistically significant difference among the 5 etiologies of TBN (P = 0.046).

Conclusions

Most common CT findings of TBN were ascites, abnormal bowel wall enhancement, dilatation, and mesenteric fat stranding. Wall thickness differentiated five etiologies, being most thickened in venous AMI and normal in arterial AMI.

Unenhanced CT-based predictive model to identify small bowel necrosis in patients with mechanical small bowel obstruction

OBJECTIVES

To investigate the diagnostic value of unenhanced CT in mechanical small bowel obstruction (SBO) with small bowel necrosis, and to establish a predictive model.

METHODS

From May 2017 to December 2021, the patients with mechanical SBO admitted to our hospital were retrospectively collected. Taking pathology-confirmed small bowel necrosis as the gold standard, the experimental group was composed of patients with small bowel necrosis confirmed by pathology, and the control group was composed of patients with no intestinal necrosis confirmed by surgery or successful conservative treatment with no recurrence of intestinal obstruction during 1-month followed-up.

RESULTS

A total of 182 patients were enrolled in this study, 157 patients underwent surgery, of which 35 patients were accompanied with small bowel necrosis and 122 patients were not (33 patients with ischemic findings at surgery without necrosis). Finally, there were 35 patients in the experimental group and 147 patients in the control group. Multivariable logistic regression showed that increased attenuation of small bowel wall (P = 0.002), diffuse mesenteric haziness (P = 0.010), difference of CT value between mesenteric vessel and aorta (P = 0.025) and U-/C-shaped small bowel loop (P = 0.010) were independent risk factors for the diagnosis of mechanical SBO with small bowel necrosis. Through internal verification, the area under curve (AUC) of the predictive model reached 0.886 (95%CI: 0.824-0.947), and the calibration result was moderate.

CONCLUSION

Multiple features (increased attenuation of small bowel wall; difference of CT values between mesenteric vessel and aorta; diffuse mesenteric haziness; and U-/C-shaped small bowel loop) of unenhanced CT have clinical value in the diagnosis of mechanical SBO with small bowel necrosis. The predictive model based on these four features could achieve satisfactory efficiency.

Colorectal Cancer-The "Parent" of Low Bowel Obstruction

Introduction: Despite the improvement of early diagnosis methods for multiple pathological entities belonging to the digestive tract, bowel obstruction determined by multiple etiologies represents an important percentage of surgical emergencies. General data: Although sometimes obstructive episodes are possible in the early stages of colorectal cancer, the most commonly installed intestinal obstruction has the significance of an advanced evolutionary stage of neoplastic disease. Development of Obstructive Mechanism: The spontaneous evolution of colorectal cancer is always burdened by complications. The most common complication is low bowel obstruction, found in approximately 20% of the cases of colorectal cancer, and it can occur either relatively abruptly, or is preceded by initially discrete premonitory symptoms, non-specific (until advanced evolutionary stages) and generally neglected or incorrectly interpreted. Success in the complex treatment of a low neoplastic obstruction is conditioned by a complete diagnosis, adequate pre-operative preparation, a surgical act adapted to the case (in one, two or three successive stages), and dynamic postoperative care. The moment of surgery should be chosen with great care and is the result of the experience of the anesthetic-surgical team. The operative act must be adapted to the case and has as its main objective the resolution of intestinal obstruction and only in a secondary way the resolution of the generating disease. Conclusions: The therapeutic measures adopted (medical-surgical) must have a dynamic character in accordance with the particular situation of the patient. Except for certain or probably benign etiologies, the possibility of colorectal neoplasia should always be considered, in low obstructions, regardless of the patient's age.

Small bowel obstruction: what a gastroenterologist needs to know

PURPOSE OF REVIEW

Intrabdominal adhesions and intestinal hernias are the commonest cause of small bowel obstruction. Small bowel diseases, which cause small bowel obstruction, are rarer and often poses a challenge to gastroenterologists to diagnose and treat. In this review, small bowel diseases, which predispose to small bowel obstruction, are focused on, and their challenges in diagnosis and treatment.

RECENT FINDINGS

Diagnosis of causes of partial small bowel obstruction is improved with computed tomography (CT) and magnetic resonance (MR) enterography. In fibrostenotic Crohn's strictures and NSAID diaphragm disease, endoscopic balloon dilatation can delay the need for surgery if the lesion is short and accessible; however, many may still inevitably require surgery. Biologic therapy may reduce the need for surgery in symptomatic small bowel Crohn's disease wherein the strictures are predominantly inflammatory. In chronic radiation enteropathy, only refractory small bowel obstruction and those with nutritional difficulties warrant surgery.

SUMMARY

Small bowel diseases causing bowel obstruction are often challenging to diagnose and require numerous investigations over a period of time, which often culminate with surgery. Use of biologics and endoscopic balloon dilatation can help to delay and prevent surgery in some instances.

Comprehensively evaluate the short outcome of small bowel obstruction: A novel medical-economic score system

BACKGROUND

Small bowel obstruction (SBO) still imposes a substantial burden on the health care system. Traditional evaluation systems for SBO outcomes only focus on a single element. The comprehensive evaluation of outcomes for patients with SBO remains poorly studied. Early intensive clinical care would effectively improve the short-term outcomes for SBO, however, the full spectrum of the potential risk status regarding the high complication-cost burden is undetermined.

AIM

We aim to construct a novel system for the evaluation of SBO outcomes and the identification of potential risk status.

METHODS

Patients who were diagnosed with SBO were enrolled and stratified into the simple SBO (SiBO) group and the strangulated SBO (StBO) group. A principal component (PC) analysis was applied for data simplification and the extraction of patient characteristics, followed by separation of the high PC score group and the low PC score group. We identified independent risk status on admission via a binary logistic regression and then constructed predictive models for worsened management outcomes. Receiver operating characteristic curves were drawn, and the areas under the curve (AUCs) were calculated to assess the effectiveness of the predictive models.

RESULTS

Of the 281 patients, 45 patients (16.0%) were found to have StBO, whereas 236 patients (84.0%) had SiBO. Regarding standardized length of stay (LOS), total hospital cost and the presence of severe adverse events (SAEs), a novel principal component was extracted (PC score = 0.429 × LOS + 0.444 × total hospital cost + 0.291 × SAE). In the multivariate analysis, risk statuses related to poor results for SiBO patients, including a low lymphocyte to monocyte ratio (OR = 0.656), radiological features of a lack of small bowel feces signs (OR = 0.316) and mural thickening (OR = 1.338), were identified as risk factors. For the StBO group, higher BUN levels (OR = 1.478) and lower lymphocytes levels (OR = 0.071) were observed. The AUCs of the predictive models for poor outcomes were 0.715 (95%CI: 0.635-0.795) and 0.874 (95%CI: 0.762-0.986) for SiBO and StBO stratification, respectively.

CONCLUSION

The novel PC indicator provided a comprehensive scoring system for evaluating SBO outcomes on the foundation of complication-cost burden. According to the relative risk factors, early tailored intervention would improve the short-term outcomes.

Bowel obstruction: signs indicating the need for urgent surgery

Bowel obstruction is common in emergency departments. Obstruction is more common in the small bowel than in the large bowel. The most common cause is postsurgical adhesions. Nowadays, bowel obstruction is diagnosed with multidetector computed tomography (MDCT). MDCT studies for suspected bowel obstruction should focus on four points that need to be mentioned in the report: confirming the obstruction, determining whether there is a single transition point or whether the obstruction is found in a closed loop, establishing the cause of the obstruction, and seeking signs of complications. Identifying signs of ischemia is important in the management of the patient because it enables patients at higher risk of poor outcomes after conservation treatment who could benefit from early surgical intervention to avoid greater morbidity and mortality associated with strangulation and ischemia of the obstructed bowel loop.

Pre-Peritoneal Dialysis Peritonitis After Saline Infusion Sonohysterogram in a Patient With an Embedded Catheter: A Case Report

Rationale

Clear guidelines currently exist regarding antibiotic prophylaxis for patients on peritoneal dialysis (PD) prior to common diagnostic procedures. However, these guidelines do not include patients with subcutaneously embedded PD catheters who are awaiting PD initiation although both these populations share a great deal of risk factors for infections. Issues regarding antibiotic prophylaxis and avoidable infections are bound to keep occurring if physicians are not conscious of the risks of infections shared by all patients suffering from renal failure.

Presenting concerns

Two weeks after a saline infusion sonohysterography (SIS), a 48-year-old woman with chronic kidney disease (CKD) G5 ND, type 2 diabetes, a subcutaneously embedded PD catheter, and prior abnormal uterine bleeding presented to the emergency department complaining of nausea, vomiting, diarrhea, weakness, and abdominal pain. The patient received no antibiotic prophylaxis prior to her SIS.

Diagnoses

The final diagnosis of peritonitis was established after acute kidney injury, gastroenteritis, and small bowel obstruction were considered and ruled out. A delay in the final diagnosis occurred because of the complex presentation, the fact that the patient had not yet initiated PD, and the presence of concomitant anion gap metabolic acidosis and an acute elevation of the patient's creatinine.

Interventions

The patient was started on broad-spectrum intravenous antibiotics when the diagnosis of peritonitis was established. Insulin and intravenous bicarbonate infusions were used to correct the patient's anion gap metabolic acidosis. Surgical debridement of the necrotic subcutaneous tissue and removal of the embedded PD catheter were necessary.

Outcomes

The patient's infection resolved completely as did her anion gap metabolic acidosis. The patient had to transfer permanently from PD to hemodialysis for her renal replacement therapy.

Teaching points

This case report serves as a good reminder that physicians should keep in mind the possibility of peritonitis in patients with embedded PD catheters. As these patients are also at risk of infections, antibiotic prophylaxis should be used in patients with embedded catheters in the same way it is used for PD patients prior to obstetrical, gynecological, or gastrointestinal procedures.

Internal hernia caused by a congenital peritoneal defect in the vesicouterine space

Internal hernias are protrusions of viscera that can cause obstructions such as small bowel obstruction (SBO). Diagnosis can be challenging, as they usually come with an atypical presentation. We report on a case of a woman in her early 40s, with no history of surgery or chronic illnesses, which came with abdominal pain associated with vomiting. CT scan revealed obstructed small bowel. On exploratory laparoscopy, an internal hernia through a peritoneal defect in the vesicouterine space was found, entrapping a limb of the jejunum. The entrapped loop of the small bowel was freed, the ischaemic part was resected, and the defect was closed. Our case presents the second reported case of a congenital vesicouterine defect causing SBO. It is important to consider patients presenting with SBO as a case of congenital peritoneal defect if they had no previous surgeries.

Successful Laparoscopic Management of Pericaecal Hernia Causing Small Bowel Obstruction

Management of small bowel obstruction varies depending on the cause and clinical status of patients. While most cases can be managed conservatively, a not-insignificant proportion of patients undergo surgical intervention. Laparotomy has long been the default approach for entering the abdomen in cases requiring surgical intervention, with laparoscopy largely being avoided due to abdominal distension and the risk of perforating bowels on entry. We present here the case of a 54-year-old woman who presented with signs and symptoms as well as radiological evidence of a closed-loop small bowel obstruction in her right lower quadrant. Following a brief period of nasogastric decompression, her abdominal distension improved, allowing for a laparoscopic entry where a pericaecal hernia was noted to be the cause of her obstruction. Extensive adhesiolysis without the use of an energy device successfully allowed for the reduction of the bowel contained within. No bowel resection was performed and the patient was discharged home on day 3 following her procedure. This case report successfully demonstrates the utility of using laparoscopy as an alternative to laparotomy in patients with a small bowel obstruction secondary to an internal hernia.

Role of Multi-Detector Computed Tomography in the Diagnosis of Intestinal Obstruction

INTRODUCTION

There is a need to identify patients whose small bowel obstruction (SBO) can resolve spontaneously so that unnecessary surgical interventions are avoided. This study aimed to evaluate the diagnostic accuracy of multi-detector computed tomography (MDCT) in intestinal obstruction and find out the presence, level, causes, and degree of intestinal obstruction taking intraoperative findings as gold standard.

METHODOLOGY

This cross-sectional study was conducted analyzing 147 patients that were referred from emergency with abdominal pain, abdominal distension, inability to pass flatus, and aged 18-70 years from both genders. Computed tomography (CT) examinations were done and findings like intestinal dilatation, evidence of mesenteric fat stranding, and area of transition between the dilated and collapsed loops were noted. The final report was made by the radiologist while the operative findings were reviewed from the operative notes written by operative surgeons of the same patient.

RESULTS

In a total of 147 patients, mean age was 52.38±16.01 years. There were 76 (51.70%) males and 71 (48.30%) females. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of multi-detector computed tomography scan in diagnosing intestinal obstruction, taking operative findings as gold standard, were 98.39%, 65.22%, 93.85%, 88.24%, and 93.20%, respectively.

CONCLUSION

The multi-detector CT can be used routinely as a prime modality for detecting intestinal obstruction which will result in proper and timely management for reducing the morbidity and mortality of these particular patients.

The value of MSCT in evaluating the passability of bezoar by conservative treatment for bezoars-induced small bowel obstruction

PURPOSE

To explore the multi-slice spiral computed tomography (MSCT) imaging characteristics of patients with bezoars-induced small bowel obstruction (BI-SBO) to evaluate the risk of conservative treatment.

MATERIALS AND METHODS

This retrospective study included 72 patients with BI-SBO who underwent whole-abdominal MSCT scan within 1 day before treatment. The patients were classified as the non-pass group and pass group depending on whether bezoar can pass after conservative treatment. The CT images were observed and measured by two radiologists. Statistical analysis was performed by using Student's t test, Pearson's chi-squared test, Fisher's exact test, Logistic linear regression, and receiver operating characteristic curve (ROC).

RESULTS

The study population consisted of 72 patients with a mean age of 52.2 ± 16.2 years (32 men and 40 women with an age range of 13-81 years). There were statistical differences between the two groups in the bezoar appearance, maximum HU of bezoar, thickness of intestinal wall, mesenteric haziness, mesenteric fluid, and peritoneal fluid (P = 0.002, 0.024, 0.017, 0.006, 0.021, and 0.030). The appearance of bezoar and mesenteric haziness is independent risk factors affecting whether bezoar can be passed by the conservative treatment. Sensitivity (41.7%) was decreased, NPV (76.3%) was not significantly changed, specificity (93.8%) and PPV (76.9%) were improved when both parameters were met to assess failure of conservative treatment.

CONCLUSION

The observation of important signs by MSCT and its reconstruction technology is of great clinical value in evaluating the passability of bezoar by conservative treatment, and which can provide radiographic basis for clinical treatment selection.

Inoperable Bowel Obstruction in Ovarian Cancer: Prevalence, Impact and Management Challenges

Malignant bowel obstruction (MBO) is one of the most severe complications in patients with advanced ovarian cancer, with an estimated incidence up to 50%. Its presence is related to poor prognosis and a life expectancy measured in weeks for inoperable cases. Symptoms are usually difficult to manage and often require hospitalization, which carries a high burden on patients, caregivers and the healthcare system. Management is complex and requires a multidisciplinary approach to improve clinical outcomes. Patients with inoperable MBO are treated medically with analgesics, antiemetics, steroids and antisecretory agents. Parenteral nutrition and gut decompression with nasogastric tube, venting gastrostomy or stenting may be used as supportive therapy. Treatment decision-making is challenging and often based on clinical expertise and local policies, with lack of high-quality evidence to optimally standardize management. The present review summarizes current literature on inoperable bowel obstruction in ovarian cancer, focusing on epidemiology, prognostic factors, clinical outcomes, medical management, multidisciplinary interventions and quality of life.

Progress in diagnosis and treatment of surgery-related adhesive small intestinal obstruction

Adhesive small bowel obstruction is a relatively common surgical acute abdomen, which is caused by various factors that result in the contents of the small bowel failing to pass smoothly. The clinical symptoms include abdominal pain, distension, nausea and vomiting, and defecation disorder. The chance of adhesive small bowel obstruction to develop in patients with a history of abdominal surgery is around 2.4%. This paper discusses the most recent developments in the conservative and surgical management of adhesive small bowel obstruction based on clinical manifestation, laboratory analysis, and imaging examination.

Understanding CT imaging findings based on the underlying pathophysiology in patients with small bowel ischemia

Because acute small bowel ischemia has a high mortality rate, it requires rapid intervention to avoid unfavorable outcomes. Computed tomography (CT) examination is important for the diagnosis of bowel ischemia. Acute small bowel ischemia can be the result of small bowel obstruction or mesenteric ischemia, including mesenteric arterial occlusion, mesenteric venous thrombosis, and non-occlusive mesenteric ischemia. The clinical significance of each CT finding is unique and depends on the underlying pathophysiology. This review describes the definition and mechanism(s) of bowel ischemia, reviews CT findings suggesting bowel ischemia, details factors involved in the development of small bowel ischemia, and presents CT findings with respect to the different factors based on the underlying pathophysiology. Such knowledge is needed for accurate treatment decisions.

Obstrucción intestinal por adherencias: un lienzo en blanco en el que el cirujano elige los colores

Introducción. La obstrucción intestinal es una patología de alta prevalencia. Su abordaje diagnóstico y terapéutico ha evolucionado acorde con el avance del conocimiento e implementación de la tecnología. El impacto de sus complicaciones obliga a redoblar esfuerzos en pro de lograr una mayor efectividad. Se hizo una aproximación reflexiva al problema, mediante una identificación de los puntos controversiales de interés para el cirujano general. Métodos. Se realizó una búsqueda sistemática de la literatura en varias bases de datos, utilizando dos ecuaciones de búsqueda que emplearon términos seleccionados a partir de los tesauros “Medical Subject Heading” (MeSH) y “Descriptores en Ciencias de la Salud” (DeCS). Resultados. Se recolectaron 43 artículos y a partir de ellos se construyó el texto de revisión. La identificación pronta de los posibles candidatos a cirugía, mediante un esquema diagnóstico y terapéutico, se constituye en una prioridad en el manejo de estos pacientes. De igual manera, se efectúan consideraciones en la toma de decisiones con respecto a la vía quirúrgica, así como recomendaciones técnicas operatorias producto de la experiencia y lo reportado en la literatura. Existen factores propios del cirujano, del contexto y del paciente, que inciden en la resolución del problema. Conclusión. La obstrucción intestinal y sus implicaciones clínicas obligan a una reevaluación constante de su estado del arte y avances en el manejo, tendiente a una búsqueda de oportunidades para impactar favorablemente en su curso clínico. Hay estrategias por implementar, inclusive el manejo laparoscópico en casos seleccionados.

Right Paraduodenal Hernia as a Cause of Acute Abdominal Pain in the Emergency Department: A Case Report and Review of the Literature

Paraduodenal hernias (PDHs) represent an unusual cause of acute abdominal pain in the Emergency Department (ED) and are associated with high morbidity attributable to a challenging clinical and radiological diagnosis, as signs and symptoms mimic other frequent causes of acute abdominal pain. We report a right paraduodenal hernia in a 37-year-old female patient who presented to the ED complaining of abdominal pain located in the right lower abdomen and hypogastrium, accompanied by nausea. During diagnostic work up, the abdominal computed tomography scan revealed the presence of small bowel malrotation with concomitant right paraduodenal hernia. These findings were confirmed intraoperatively. We performed a brief literature review about the clinical manifestations and treatment options of right paraduodenal hernias, which retrieved only 30 articles related to this condition. Prompt diagnosis, radiological or intraoperative, of paraduodenal hernias is crucial because nearly 50% will progress to small bowel obstruction. Therefore, it is essential for every clinician to account for them in the differential diagnosis of acute abdominal pain in the ED.

Persistently High Rates of Abdominal Computed Tomography Imaging Among Patients With Inflammatory Bowel Disease Who Present to the Emergency Department

Background

Recent guidelines recommended judicious use of abdominal computed tomography (CT) in the emergency department (ED) for inflammatory bowel disease. Trends in CT utilization over the last decade, including since the implementation of these guidelines, remain unknown.

Methods

We performed a single-centre, retrospective study between 2009 and 2018 to assess trends in CT utilization within 72 h of an ED encounter. Changes in the annual rates of CT imaging among adults with IBD were estimated by Poisson regression and CT findings by Cochran-Armitage or Cochran-Mantel Haenszel tests.

Results

A total of 3000 abdominal CT studies were performed among 14,783 ED encounters. CT utilization increased annually by 2.7% in Crohn’s disease (CD) (95% confidence interval [CI], 1.2 to 4.3; P = 0.0004), 4.2% in ulcerative colitis (UC) (95% CI, 1.7 to 6.7; P = 0.0009) and 6.3% in IBD unclassifiable (95% CI, 2.5 to 10.0; P = 0.0011). Among encounters with gastrointestinal symptoms, 60% with CD and 33% with UC underwent CT imaging in the final year of the study. Urgent CT findings (obstruction, phlegmon, abscess or perforation) and urgent penetrating findings alone (phlegmon, abscess or perforation) comprised 34% and 11% of CD findings, and 25% and 6% of UC findings, respectively. The CT findings remained stable overtime for both CD (P = 0.13) and UC (P = 0.17).

Conclusion

Our study demonstrated persistently high rates of CT utilization among patients with IBD who presented to the ED over the last decade. Approximately one third of scans demonstrated urgent findings, with a minority demonstrating urgent penetrating findings. Future studies should aim to identify patients in whom CT imaging is most appropriate.

Prediction factors for ischemia of closed-loop small intestinal obstruction

A closed-loop type of intestinal obstruction leads to ischemic necrosis. There have been indicators that may predict ischemia and its severity, such as biomarkers and computed tomography scans. In addition to the usual inflammation markers, such as white blood count-neutrophil count and c-reactive protein (CRP), the most accurate predictors that have been proposed are the CRP-to-albumin ratio, the neutrophil/lymphocyte ratio and the platelet/lymphocyte ratio. Endothelin 1 is another promising biomarker of ischemia that must be assessed in daily clinical practice. Advanced age and frailty status were assessed as predictors of mortality. A timely operative procedure without any delay ensures a better outcome.

Efficacy of Abdominal Ultrasonography for Differentiation of Gastrointestinal Diseases in Calves

Simple Summary

Gastrointestinal diseases represent one of the common causes of bovine acute abdomen, such as abdominal distention, abdominal pain, and cessation of defecation. In addition to the observable signs when performing routine auscultation, rectal palpation, and biochemical examinations of ruminal fluid and blood, these clinical observations can provide evidence suggestive of these diseases, but they generally result in an inconclusive diagnosis. Therefore, exploratory laparotomy is often used because it facilitates both diagnosis and therapeutic decisions. For bovines, abdominal ultrasonography is frequently utilized as a convenient imaging modality to assist accurate diagnosis and contribute to subsequent appropriate therapeutic choices for bovine gastrointestinal diseases. According to recent trends in human medicine and small animal practice, technical improvements have led to developments in the diagnostic value of abdominal ultrasonography, including scanning methods and the establishment of valuable diagnostic signs specific to a particular disease, e.g., a target sign for intussusception.

Abstract

This study investigated the clinical efficacy of abdominal ultrasonography for abomasal dilation in three calves, intestinal volvulus in five calves, intussusception in one calf, and internal hernia in one calf. In the abdominal ultrasonograms of the abomasal dilation cases, this disease was commonly characterized by severely extended lumens, including heterogeneously hyperechoic ingesta without intraluminal accumulations of gas. In the animals with intestinal volvulus and intussusception, a to-and-fro flow was observed to be a common ultrasonographic characteristic that led to suspicion of an intestinal obstruction. The use of abdominal ultrasonography for five cases with intestinal volvulus gave no reason to suspect this disease, despite its efficacy in one case, based on an acutely angled narrowing. Although three of five animals with intestinal volvulus had intestinal ruptures, no ultrasonographic evidence could be obtained. When abdominal ultrasonography was used for one case with intussusception, this pathological condition could be strongly suspected, as a “target” sign was observed. This finding supported surgical intervention for this case, followed by treatment with manual reduction, resulting in a favorable outcome. In terms of the differential and definitive diagnosis for various intestinal diseases, abdominal ultrasonography may be poor at providing indicative evidence, but very helpful for confirming intestinal obstruction.

Simultaneous Sigmoid Volvulus and Small Bowel Obstruction: A Case Report

Sigmoid volvulus and small bowel obstruction are typically thought to be separate clinical pathologies with distinct clinical features, diagnostic criteria, and treatment strategies. We present a rare case of simultaneous sigmoid volvulus and small bowel obstruction. To our knowledge, this is the first such case in literature and presented a unique set of challenges in regard to treatment and management. This case discusses a different approach to the surgical management of sigmoid volvulus and small bowel obstruction, which is markedly different from the expected and traditional surgical management of isolated sigmoid volvulus and small bowel obstruction.

Predicting the outcome of closed-loop small bowel obstruction by preoperative characteristics

BACKGROUND

Closed-loop small bowel obstruction (CL-SBO) can threaten the viability of the intestine by obstructing a bowel segment at two adjacent points. Prompt recognition and surgery are crucial.

AIM

To analyze the outcomes of patients who underwent surgery for CL-SBO and to evaluate clinical predictors.

METHODS

Patients who underwent surgery for suspected CL-BSO on computed tomography (CT) at a single center between 2013 and 2019 were evaluated retrospectively. Patients were divided into three groups by perioperative outcome, including viable bowel, reversible ischemia, and irreversible ischemia. Clinical and laboratorial variables at presentation were compared and postoperative outcomes were analyzed.

RESULTS

Of 148 patients with CL-SBO, 28 (19%) had a perioperative viable small bowel, 86 (58%) had reversible ischemia, and 34 (23%) had irreversible ischemia. Patients with a higher age had higher risk for perioperative irreversible ischemia [odds ratio (OR): 1.03, 95% confidence interval (CI): 0.99-1.06]. Patients with American Society of Anaesthesiologists (ASA) classification ≥ 3 had higher risk of perioperative irreversible ischemia compared to lower ASA classifications (OR: 3.76, 95%CI: 1.31-10.81). Eighty-six patients (58%) did not have elevated C-reactive protein (> 10 mg/L), and between-group differences were insignificant. Postoperative in-hospital stay was significantly longer for patients with irreversible ischemia (median 8 d, P = 0.001) than for those with reversible ischemia (median 6 d) or a viable bowel (median 5 d). Postoperative morbidity was significantly higher in patients with perioperative irreversible ischemia (45%, P = 0.043) compared with reversible ischemia (20%) and viable bowel (4%).

CONCLUSION

Older patients or those with higher ASA classification had an increased risk of irreversible ischemia in case of CL-SBO. After irreversible ischemia, postoperative morbidity was increased.

Prediction and management of strangulated bowel obstruction: a multi-dimensional model analysis

BACKGROUND

Distinguishing strangulated bowel obstruction (StBO) from simple bowel obstruction (SiBO) still poses a challenge for emergency surgeons. We aimed to construct a predictive model that could distinctly discriminate StBO from SiBO based on the degree of bowel ischemia.

METHODS

The patients diagnosed with intestinal obstruction were enrolled and divided into SiBO group and StBO group. Binary logistic regression was applied to identify independent risk factors, and then predictive models based on radiological and multi-dimensional models were constructed. Receiver operating characteristic (ROC) curves and the area under the curve (AUC) were calculated to assess the accuracy of the predicted models. Via stratification analysis, we validated the multi-dimensional model in the prediction of transmural necrosis both in the training set and validation set.

RESULTS

Of the 281 patients with SBO, 45 (16.0%) were found to have StBO, while 236(84.0%) with SiBO. The AUC of the radiological model was 0.706 (95%CI, 0.617-0.795). In the multivariate analysis, seven risk factors including pain duration ≤ 3 days (OR = 3.775), rebound tenderness (OR = 5.201), low-to-absent bowel sounds (OR = 5.006), low levels of potassium (OR = 3.696) and sodium (OR = 3.753), high levels of BUN (OR = 4.349), high radiological score (OR = 11.264) were identified. The AUC of the multi-dimensional model was 0.857(95%CI, 0.793-0.920). In the stratification analysis, the proportion of patients with transmural necrosis was significantly greater in the high-risk group (24%) than in the medium-risk group (3%). No transmural necrosis was found in the low-risk group. The AUC of the validation set was 0.910 (95%CI, 0.843-0.976). None of patients in the low-risk and medium-risk score group suffered with StBO. However, all patients with bowel ischemia (12%) and necrosis (24%) were resorted into high-risk score group.

CONCLUSION

The novel multi-dimensional model offers a useful tool for predicting StBO. Clinical management could be performed according to the multivariate score.

Meckel's diverticulum causing acute intestinal obstruction: A case report and comprehensive review of the literature

Introduction

Meckel's diverticulum is a congenital anomaly that is often detected incidentally. When it presents symptomatically, it causes painless gastrointestinal bleeding. Nevertheless, in rare instances, it can cause acute intestinal obstruction, often obscuring the true clinical picture.

Case presentation

A 31-year-old male presented to the emergency department with a 24-h history of unremitting nausea, biliary emesis, abdominal distension, and absolute constipation. After ruling out the most common etiologies of acute bowel obstruction, radiological imaging was obtained and was suggestive of meckel's diverticulum. Laparoscopic meckel's diverticulectomy was performed, with the subsequent histopathological analysis confirming ectopic gastric tissue.

Discussion

Meckel's diverticulum occurs consequent to incomplete obliteration of the vitelline or omphalomesenteric duct, which connects the developing intestines to the yolk sac. It is found in roughly 2% of the population, of which only about 4% may become symptomatic due to any number of complications. Specifically, small bowel obstruction (SBO) and diverticulitis secondary to ectopic gastric or pancreatic tissue are the most common presentations of symptomatic MD.

Conclusion

Although relatively rare in adults, MD should be considered in the list of differentials in patients with intussusception leading to SBO, especially on a background history unremarkable for the most common etiologies causing SBO including post-operative adhesions and hernias.

Machine Learning Based Prediction Model for Closed-Loop Small Bowel Obstruction Using Computed Tomography and Clinical Findings

PURPOSE

The aim of the study was to develop a prediction model for closed-loop small bowel obstruction integrating computed tomography (CT) and clinical findings.

METHODS

The radiology database and surgical reports from 2 suburban teaching hospitals were retrospectively reviewed for patients undergoing surgery for suspected closed-loop small bowel obstruction (CLSBO). Two observers independently reviewed the CT scans for the presence of imaging features of CLSBO, blinded to the surgically confirmed diagnosis and clinical parameters. Random forest analysis was used to train and validate a prediction model for CLSBO, by combining CT and clinical findings, after randomly splitting the sample into 80% training and 20% test subsets.

RESULTS

Surgery confirmed CLSBO in 185 of 223 patients with clinically suspected CLSBO. Age greater than 52 years showed 2.82 (95% confidence interval = 1.13-4.77) times higher risk for CLSBO (P = 0.021). Sensitivity/specificity of CT findings included proximal dilatation (97/5%), distal collapse (96/2%), mesenteric edema (94/5%), pneumatosis (1/100%), free air (1/98%), and portal venous gas (0/100%). The random forest model combining imaging/clinical findings yielded an area under receiver operating curve of 0.73 (95% confidence interval = 0.58-0.94), sensitivity of 0.72 (0.55-0.85), specificity of 0.8 (0.28-0.99), and accuracy of 0.73 (0.57-0.85). Prior surgery, age, lactate, whirl sign, U/C-shaped bowel configuration, and fecalization were the most important variables in predicting CLSBO.

CONCLUSIONS

A random forest model found clinical factors including prior surgery, age, lactate, and imaging factors including whirl sign, fecalization, and U/C-shaped bowel configuration are helpful in improving the prediction of CLSBO. Individual CT findings in CLSBO had either high sensitivity or specificity, suggesting that accurate diagnosis requires systematic assessment of all CT signs.

Evaluating suspected small bowel obstruction with the water-soluble contrast challenge

With optimized technique, the water-soluble contrast challenge is effective at triaging patients for operative vs non-operative management of suspected small bowel obstruction. Standardized study structure and interpretation guidelines aid in clinical efficacy and ease of use. Many tips and tricks exist regarding technique and interpretation, and their understanding may assist the interpreting radiologist. In the future, a CT-based water-soluble contrast challenge, utilizing oral contrast given as part of the initial CT examination, might allow for a more streamlined algorithm and provide more rapid results.

Non-toxic Megacolon Secondary to High-Grade Large-Bowel Obstruction

A 92-year-old male presented from an outside hospital for treatment of a chronic obstructive pulmonary disease exacerbation (COPD) and subsequently developed worsening abdominal distention with pain during the course of his hospitalization. He was found to have a high-grade large-bowel obstruction with a dilated colon of 20 cm measuring upward. The patient ultimately underwent a hemicolectomy to prevent bowel ischemia and reformation of another volvulus. We present this case to elucidate the need for vigilant monitoring in patients with chronic bowel obstruction due to lack of typical symptoms, to demonstrate a successful management approach, and to exhibit an extreme example of the resulting megacolon.

Small bowel obstruction precipitated by intussusception of Meckel’s diverticulum

Small bowel obstruction (SBO) secondary to intussusception of Meckel’s diverticulum (MD) is a rare cause of acute abdominal pain that may warrant urgent surgical treatment. Volvulus or intussusception of the small bowel with presence of MD as the lead point is the most commonly reported etiology of Meckel’s related obstructions. We report an interesting case of a small bowel obstruction caused by the intussusception of an MD within its own lumen. The case involves a 30-year-old male who presented to the emergency room with acute, severe abdominal pain with an abdominal computed tomography (CT) showing a distal high-grade SBO. Decision was made to take the patient to the operating room urgently due to his clinical examination and radiologic imaging, specifically CT scan. Diagnostic laparoscopy was performed and subsequently converted to an exploratory laparotomy, which revealed the intussuscepted MD with focal necrosis into the distal small bowel causing an SBO. A segmental small bowel resection with hand sewn primary anastomosis was performed. The case presents an interesting challenge in deciding when to take a patient with an SBO to the operating room versus initial conservative management and what the treatment should be if an MD is encountered. In addition, the case emphasizes the importance of history and physical exam findings in coordination with radiologic imaging in helping to make appropriate decisions in a timely manner for operative vs conservative management of an SBO. It reminds us that, Meckel’s diverticulum, although less commonly the cause of a small bowel obstruction in the adult population, needs to be on the differential diagnosis and we need to have a high clinical suspicion for this possibility to ensure appropriate treatment in a timely manner.