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

Delayed diagnosis in a child with strangulated mesenteric hernia

Background

Strangulated intestinal obstruction is a life-threatening condition that should be considered as a differential diagnosis in children with shock. However, it has pitfalls in diagnosis and can lead to diagnostic errors.

Case Presentation

A 3-month-old male patient presented with a pale complexion lasting 2 h and abnormal crying. He was in shock with lactic acidosis, altered mental status, and slight abdominal distension. He required volume resuscitation, vasoactive agents, and transfusion. On Day 2, he had marked abdominal distension and acute kidney injury, which required continuous kidney replacement therapy. Contrast-enhanced computed tomography revealed extensive intestinal ischemia. It took 33.5 h from his arrival to the computed tomography, leading to operative management. The small intestine had entered a mesenteric hiatus, leading to ischemia. He was diagnosed with strangulated mesenteric hernia.

Conclusion

In this case, four pitfalls led to delayed diagnosis. Factors for diagnostic errors specific to strangulated intestinal obstruction and intensive care should be noted.

Current Management of Adhesive Small Bowel Obstructions in Children

Adhesive small bowel obstructions are a common cause of morbidity in children who underwent prior abdominal surgery. The concept of partial versus complete bowel obstruction is outdated and lacks precision to be clinically useful. Identifying patients with indications for immediate operative intervention is critical and must be recognized to limit morbidity. Clinical protocols and contrast challenge algorithms have attempted to identify patients that will resolve their bowel obstruction nonoperatively; there has been slow uptake in the pediatric patient population versus adults until recently. Incorporating predictive models and standardized contrast challenge protocols will help reduce interpractitioner variability and improve clinical outcomes.

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.

The significance of abdominal radiographs with paucity of gas in pediatric adhesive small bowel obstruction

PURPOSE

Management of children with adhesive small bowel obstruction (ASBO) is often based on abdominal radiographs (AXR). Our purpose was to determine the significance of paucity of gas on initial AXR.

METHODS

Retrospective, single center review of children with ASBO between 2011 and 2015. Analysis included chi-square, non-parametric tests and multivariate regression.

RESULTS

Of 207 cases, 99 were operative. Initial AXR showed paucity of gas in 41% and gaseous loops in 59%. Paucity was more common in operative patients (49% vs. 32%, p = 0.01). At operation, 71% of patients with paucity had closed loop or high-grade obstruction, compared to 29% of patients with gaseous loops (p = <0.001).

CONCLUSION

For children with ASBO with paucity of gas on AXR, complicated obstruction (closed loop or high-grade) should be considered. In children with high clinical suspicion of complicated obstruction, additional imaging with CT or SBFT may clarify the clinical picture.

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.

Adhesive small bowel obstruction--acute management and treatment in children

Adhesive small bowel obstruction is a significant cause of short- and long-term morbidity in infants and children. Unfortunately, the majority of scientific literature relative to adhesive obstructions continues to be dominated by adult studies. In this article, the existing literature for infant and pediatric adhesive obstructions is reviewed, with relevant comparisons to the available adult data. In addition, general guidelines for the management of infant and pediatric adhesive obstructions are recommended, based on the best available evidence.

Small bowel feces sign in association with occlusive mesenteric ischemia

Small bowel feces sign (SBFS) is a computed tomography (CT) finding that appears as fecal like material in dilated small bowel loops. This sign is usually seen in association with gradually progressive small bowel obstruction. We present a case of occlusive mesenteric ischemia in which the SBFS appeared on CT scan early on in the course of the disease. We put forward a suggested alternative mechanism to the appearance of this sign in association with mesenteric ischemia. The SBFS might have the potential to serve as an early sign of mesenteric ischemia on CT scan.