MDCT findings in small bowel obstruction: implications of the cause and presence of complications on treatment decisions. ACTA ACUST UNITED AC. 2015;40:2248-2262. [PMID: 26070748 DOI: 10.1007/s00261-015-0477-x]

Evaluation of Multidetector Computed Tomography in the Diagnosis of Intestinal Obstruction

Background Acute intestinal obstruction is a commonly encountered surgical emergency that is prevalent worldwide and has substantial morbidity and fatality rates. Therefore, swift and precise diagnosis is essential. While mortality rates in urban areas have declined due to timely medical intervention following early detection, the situation contrasts starkly in rural areas. Delays in presentations often lead to complications because of hesitancy toward surgery, economic challenges, and limited access to healthcare information. Therefore, this study aimed to evaluate how well multidetector computed tomography (MDCT) can help determine the site, cause, and level of intestinal obstruction compared to what the surgeons confirmed intraoperatively. Methodology A prospective study involving 101 patients was conducted at a tertiary care center in western Maharashtra from July 2022 to July 2024. The emergency department referred patients with clinical symptoms such as nausea and vomiting, abdominal distension, abdominal pain, inability to pass flatus, constipation, or diarrhea, which are commonly seen with intestinal obstruction. The study involved all patients who underwent a contrast-enhanced MDCT scan using both intravenous and oral contrast agents. We selected patients from both genders, regardless of their age; however, considerations were taken to include characteristics convenient and relevant to the study. Patients with abnormal serum creatinine levels or allergies to contrast were excluded from the study. We conducted CT examinations, noting findings such as the transition point between the dilated and collapsed loops, mesenteric fat stranding, and intestinal dilatation. An experienced radiologist made the final report, and the operating surgeons' notes on laparoscopy or open surgery for the same patient were reviewed to understand the operative findings. Results MDCT scans had high diagnostic accuracy for small and large bowel obstruction. Of the 101 patients, the mean age was 43.7 years. There were 70 (69.30%) males and 31 (30.69%) females. Sensitivity was 100%, specificity was 98.1%, positive predictive value was 83.7%, and negative predictive value was 100%. Conclusions MDCT demonstrated high sensitivity and specificity for diagnosing and determining the underlying cause of intestinal obstruction. It identified the location of the obstruction and discerned whether it originated from intrinsic, extrinsic, or intraluminal factors.

The role of radiology in diagnosing gastrointestinal tract perforation

Spontaneous, iatrogenic or surgical perforation of the whole gastrointestinal wall can lead to serious complications, resulting in increased morbidity and mortality. Optimal patient management requires early clinical appraisal and prompt imaging evaluation. Both radiologists and referring clinicians should recognize the importance of choosing the ideal imaging modality and the usefulness of oral and rectal contrast medium. Surgeons and radiologists should be familiar with CT and fluoroscopy findings of the normal and pathologic anatomy after esophageal, stomach or colon surgery. Specifically, they should be able to differentiate innocuous from clinically-relevant, life-threatening postoperative complications to guide appropriate treatment. Advantages of esophagram, CT-esophagram, CT after rectal contrast enema and other imaging modalities are discussed.

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

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

[Preoperative diagnosis of intestinal ischemia in small bowel obstruction. Only computed tomography? A multiple-center observational study]

OBJECTIVE

To evaluate the accuracy of clinical, laboratory and instrumental methods for diagnosis of intestinal ischemia following small bowel obstruction in emergency hospitals.

MATERIAL AND METHODS

Multiple-center observational retrospective study enrolled 158 consecutive patients with benign small bowel obstruction (SBO) treated at four hospitals between May 2017 and December 2019. The role of clinical, laboratory and instrumental diagnostic methods for intestinal ischemia was analyzed. We assessed the impact of CT and contrast-enhanced X-ray examination on survival of patients.

RESULTS

Laboratory parameters as criteria of ischemia following SBO were similar (leukocytosis >14·10⁹/l (p=1.0), serum lactate >2.0 mmol/l (p=0.28), heart rate >90/min (p=0.71) and fever (p=0.74)). The only laboratory indicator with significant differences was serum sodium. Decrease in leukocytosis over time was less common in patients with ischemia (25% vs. 61.3%, p=0.012). Univariate Kaplan-Meier analysis did not establish the effect of CT on survival (7.8% [95% CI 7.6-8.0] vs. 6.5% [95% CI 6.3-6.6], p=0.786). Logistic regression revealed 6.4-fold higher chance of accurate diagnosis (ischemia/non-ischemia) in case of CT-based conclusion of ischemia (95% CI 0.025-0.85). Univariate analysis showed that the use of water-soluble contrast for adhesive SBO was associated with lower mortality (4.1% [95% CI 4.0-4.2] vs. 14.3% [95% CI 13.7-14.9], p=0.032) without assessing the comparability of groups.

CONCLUSION

Routine laboratory tests were not specific for intestinal ischemia. Therefore, they should not be considered as the only criteria for surgical tactics in intestinal obstruction. Only CT showed acceptable diagnostic accuracy, and, apparently, only this method has real prospects for improving the quality of diagnosis due to technical support, training of surgeons and specialists for diagnosis.

Multidetector computed tomography diagnosis of small bowel intussusceptions in adults: observations in a 10-year single-center study

BACKGROUND

The etiologies of small bowel intussusception (SBI) in adults are varied.

PURPOSE

To investigate multidetector computed tomography (MDCT) characteristics in adults with neoplastic and non-neoplastic SBI.

MATERIAL AND METHODS

Clinical data and MDCT images diagnosed with SBI in adults from January 2010 to May 2020 were retrospectively reviewed.

RESULTS

The study included a total of 71 patients. Forty-two patients had a combined total of 55 neoplastic intussusceptions, including 29 patients with benign tumors and 13 patients with malignant tumors. Twenty-nine patients had a combined total of 36 non-neoplastic intussusceptions, of which the condition was idiopathic in 23 patients and cased by non-neoplastic benign lesions in six patients. There were no significant differences in patient age or sex ratio in the neoplastic and non-neoplastic groups. In the non-neoplastic group the intussusceptions were shorter in length (3.6 cm vs. 13.2 cm, P<0.05) and smaller in transverse diameter (2.8 cm vs. 4.2 cm, P<0.05), and less likely to be associated with intestinal obstruction (2 vs. 18, P<0.05). The percentage of patients with multiple intussusceptions was greater in the neoplastic group (10/42, 23.8% vs. 4/29, 13.8%). In the non-neoplastic group only one lead point was detected (in a patient with Meckel's diverticulum), whereas lead points were detected in all 55 intussusceptions in the neoplastic group.

CONCLUSION

There are differences in the clinical and MDCT manifestations of adult neoplastic and non-neoplastic SBIs. Whether a lead point is present or not has implications with regard to deciding on the most appropriate treatment and avoiding unnecessary surgery.

Correlation of CT findings with intra-operative outcome in closed-loop small bowel obstruction (CL-SBO)

PURPOSE

To correlate CT-findings in patients with closed-loop small bowel obstruction (CL-SBO) with perioperative findings, to identify patients who require immediate surgical intervention. Secondary purpose was to substantiate the role of radiologists in predicting perioperative outcome.

METHODS

Data were retrospectively obtained from patients with surgically confirmed CL-SBO, between September 2013 and September 2019. Three radiologists reviewed CTs to assess defined CT features and predict patient outcome for bowel wall ischemia and necrosis using a likelihood score. Univariate statistical analyses were performed and diagnostic performance parameters and interobserver agreement were assessed for each feature.

RESULTS

Of 148 included patients, 28 (19%) intraoperatively had viable bowel and 120 (81%) had bowel wall ischemia or necrosis. Most CT characteristics, as well as the likelihood of ischemia and necrosis, found fair or moderate multirater agreement. Increased attenuation of bowel wall and mesenteric vessels on non-contrast-enhanced CT had a specificity for bowel ischemia or necrosis of 100% (sensitivity respectively 48% (p < 0.001) and 21% (p = 0.09)). Mesenteric edema had high sensitivity for ischemia or necrosis (90%), but specificity of only 26% (p < 0.001). For mesenteric fluid, sensitivity was 60% and specificity 57% (p = 0.004). Decreased enhancement of bowel wall in both arterial and PV-phase showed significant correlation, respectively a sensitivity of 58% and 42%, and specificity of 88% and 79% (both p < 0.001). Likelihood of both ischemia and necrosis were significantly correlated with perioperative outcome (p < 0.001).

CONCLUSION

CT findings concerning mesenteric and bowel wall changes, as well as radiologists' judgement of likelihood of ischemia and necrosis are significantly correlated with perioperative outcome of bowel wall ischemia and necrosis in patients with CL-SBO.

Computed Tomography in Emergency Diagnosis and Management Considerations of Small Bowel Obstruction for Surgical vs. Non-surgical Approach

BACKGROUND

Small bowel obstruction (SBO) accounts for 15% of abdominal pain complaints referred to emergency departments and imposes significant financial burdens on the healthcare system. The absence of passage of flatus or stool and abdominal distention are reported as the most common symptom and a sign of SBO, respectively. Patients who do not demonstrate severe clinical or imaging findings are typically treated with conservative approaches. Patients with clinical signs of sepsis or physical findings of peritonitis are often instantly transferred to the operating room without supplementary imaging assessment. However, in cases where symptoms are non-specific, or the physical examination is challenging, such as in cases with loss of consciousness, the diagnosis can be complicated. This paper discusses the key findings detectable on Computed tomography (CT), which are vital for the emergent triage, proper treatment, and decision making in patients with speculated SBO.

METHOD

Narrative review of the literature.

RESULTS AND CONCLUSION

CT plays a key role in emergent triage, proper treatment, and decision making. It provides high sensitivity, specificity, and accuracy in the detection of early-stage obstruction and acute intestinal vascular compromise. It can also differentiate between various etiologies of this entity which is considered an important criterion in the triage of patients into surgical vs. non-surgical treatment. There are multiple CT findings, such as mesenteric edema, lack of the small-bowel feces, bowel wall thickening, fat stranding in the mesentery, and intraperitoneal fluid, which are predictive of urgent surgical exploration.

Gastrointestinal perforation: clinical and MDCT clues for identification of aetiology

Gastrointestinal tract (GIT) perforation is a common medical emergency associated with considerable mortality, ranging from 30 to 50%. Clinical presentation varies: oesophageal perforations can present with acute chest pain, odynophagia and vomiting, gastroduodenal perforations with acute severe abdominal pain, while colonic perforations tend to follow a slower progression course with secondary bacterial peritonitis or localised abscesses. A subset of patients may present with delayed symptoms, abscess mimicking an abdominal mass, or with sepsis.

Direct multidetector computed tomography (MDCT) findings support the diagnosis and localise the perforation site while ancillary findings may suggest underlying conditions that need further investigation following primary repair of ruptured bowel. MDCT findings include extraluminal gas, visible bowel wall discontinuity, extraluminal contrast, bowel wall thickening, abnormal mural enhancement, localised fat stranding and/or free fluid, as well as localised phlegmon or abscess in contained perforations.

The purpose of this article is to review the spectrum of MDCT findings encountered in GIT perforation and emphasise the MDCT and clinical clues suggestive of the underlying aetiology and localisation of perforation site.

Imaging of Abdominal Postoperative Complications

We present a case-based review of abdominal postoperative complications, organized by organ system affected, including wound/superficial, hepatobiliary, pancreatic, gastrointestinal, genitourinary, and vascular complications. Both general complications and specific considerations for certain types of operations are described, as well as potential pitfalls that can be confused with complications. Representative cases are shown using all relevant imaging modalities, including CT, fluoroscopy, ultrasound, MRI, and nuclear medicine. Management options are also described, highlighting those that require radiologist input or intervention.

Evaluation of a water-soluble contrast protocol for small bowel obstruction: A southwestern surgical congress multicenter trial

Differentiation between SBO that will resolve with supportive measures and those requiring surgery remains challenging. WSC administration may be diagnostic and therapeutic. The purpose of this study was to evaluate use of a SBO protocol using WSC challenge. A protocol was implemented at five tertiary care centers. Demographics, prior surgical history, time to operation, complications, and LOS were analyzed. 283 patients were admitted with SBO; 13% underwent immediate laparotomy; these patients had a median LOS of 7.5 days. The remaining 245 were candidates for WSC challenge. Of those, 80% received contrast. 139 (71%) had contrast passage to the colon. LOS in these patients was 4 days. Sixty-five patients (29%) failed contrast passage within 24 h and underwent surgery. LOS was 9 days. 8% of patients in whom contrast passage was observed at 24 h nevertheless subsequently underwent surgery. 4% of patients who failed WSC challenge did not proceed to surgery. Our multicenter trial revealed that implementation of a WSC protocol may facilitate early recognition of partial from complete obstruction.

Bowel obstruction: a narrative review for all physicians

Small and large bowel obstructions are responsible for approximately 15% of hospital admissions for acute abdominal pain in the USA and ~ 20% of cases needing acute surgical care. Starting from the analysis of a common clinical problem, we want to guide primary care physicians in the initial management of a patient presenting with acute abdominal pain associated with intestinal obstruction.

A closer look at the stoma: multimodal imaging of patients with ileostomies and colostomies

Nowadays, large numbers of ileostomies and colostomies are created during surgical management of a variety of intestinal disorders. Depending on indication, surgical technique and emergency versus elective conditions, stomas may be either temporary or permanent. As a result, patients with ileostomies and colostomies are commonly encountered in Radiology departments, particularly during perioperative hospitalisation following stoma creation or before recanalisation, and when needing CT or MRI studies for follow-up of operated tumours or chronic inflammatory bowel diseases. However, the stoma site is commonly overlooked on cross-sectional imaging.Aiming to improve radiologists' familiarity with stoma-related issues, this pictorial essay concisely reviews indications and surgical techniques for ileostomies and colostomies, and presents state-of-the art multimodal imaging in patients living with a stoma, including water-soluble contrast stomal enema (WSC-SE), CT and MRI techniques, interpretation and expected findings. Afterwards, the clinical features and imaging appearances of early and late stoma-related complications are illustrated with imaging examples, including diversion colitis.When interpreting cross-sectional imaging studies, focused attention to the stoma site and awareness of expected appearances and of possible complications are required to avoid missing significant changes requiring clinical attention. Additionally, dedicated imaging techniques such as WSC-SE and combined CT plus WSC-SE may be helpful to provide surgeons the appropriate clinical information required to direct management.

Obstruction reduction: Use of water-soluble contrast challenge to differentiate between partial and complete small bowel obstruction

Differentiating SBO that will resolve conservatively from those requiring surgery remains challenging. Water-soluble contrast administration may be diagnostic and therapeutic. Our study evaluated use of a WSC challenge protocol. We hypothesize that protocol use discriminates between surgical SBO and obstructions which can be managed non-operatively. Demographics, prior surgeries, time to operation, complications, and LOS were analyzed. 108 patients were admitted with SBO. 13% underwent immediate laparotomy with concern for bowel compromise; these had a median LOS of 8.5 days. 91 received WSC protocol. Of these, 77% had contrast passage to the colon. Of the 48 in whom contrast passed between 0 and 12 h, LOS was 2 days. Of the 22 patients in whom contrast passed between 12 and 24 h, LOS was 4.5 days. 21 had failure of contrast passage; 18 of those underwent surgery after 24 h as a result. Of the 21 patients who failed WSC challenge, median LOS was 8 days. WSC protocol implementation facilitates early recognition of partial from complete obstruction and may decrease LOS. Our findings warrant further evaluation with a multicenter trial.

Optimized protocol of multiple post-processing techniques improves diagnostic accuracy of multidetector computed tomography in assessment of small bowel obstruction compared with conventional axial and coronal reformations

BACKGROUND

Axial and coronal reformations have been a widely used image post-processing protocol for the ordinary multidetector computed tomography (MDCT) examination of patients with small bowel obstruction (SBO) or other abdominal diseases. The diagnostic accuracy of MDCT for assessing SBO is expected to be further improved through the use of multiple post-processing techniques.

AIM

To systemically evaluate the diagnostic accuracy and efficiency of an optimized protocol using multiple post-processing techniques for MDCT assessment of SBO and secondary bowel ischemia.

METHODS

This retrospective cross-sectional study included 106 patients with clinically suspected SBO. Two readers applied three protocols to image post-processing and interpretation of patients’ MDCT volume data. We compared the three protocols based on time spent, number of images, diagnostic self-confidence, agreement, detection rate, and accuracy of detection of SBO and secondary bowel ischemia.

RESULTS

Protocol 2 resulted in more time spent and number of images than protocols 1 and 3 (P < 0.01), but the results of the two readers using the same protocol were not different (P > 0.05). Using protocol 3, both readers added multiple post-processing techniques at frequencies of 29.2% and 34.9%, respectively, for obstruction cause, and 32.1% and 30.2%, respectively, for secondary bowel ischemia. Protocols 2 and 3 had higher total detection rates of obstruction cause and secondary bowel ischemia than protocol 1 (P < 0.01), but no difference was detected between protocols 2 and 3 (P > 0.05). The accuracy, sensitivity, specificity, positive predictive value and negative predictive value of protocols 2 and 3 were superior to those of protocol 1 for evaluating obstruction cause and secondary bowel ischemia.

CONCLUSION

Our optimized protocol of multiple post-processing techniques can both guarantee efficiency and improve diagnostic accuracy of MDCT for assessing SBO and secondary bowel ischemia.

Small Bowel Obstruction

Identifying patients with small bowel obstruction who need operative intervention and those who will fail nonoperative management is a challenge. Without indications for urgent intervention, a computed tomography scan with/without intravenous contrast should be obtained to identify location, grade, and etiology of the obstruction. Most small bowel obstructions resolve with nonoperative management. Open and laparoscopic operative management are acceptable approaches. Malnutrition needs to be identified early and managed, especially if the patient is to undergo operative management. Confounding conditions include age greater than 65, post Roux-en-Y gastric bypass, inflammatory bowel disease, malignancy, virgin abdomen, pregnancy, hernia, and early postoperative state.

Intestinal transplants: review of normal imaging appearance and complications

Intestinal transplant (IT) is one of the least common forms of organ transplant but is increasing both in volume of cases and number of centers performing intestinal transplants, with the busiest centers in North America and Europe. IT can be performed in isolation or as part of a multivisceral transplant (MVT). Intestinal failure either in the form of short gut syndrome or functional bowel problems is the primary indication for IT. The normal post-surgical anatomy can be variable due to both recipient anatomy in regard to amount of residual bowel and status of native vasculature as well as whether the transplant is isolated or part of a multivisceral transplant. Complications of isolated IT and IT as part of an MVT include complications shared with other types of organ transplants such as infection, rejection, post-transplant lymphoproliferative disorder and graft versus host disease. Mechanical bowel complications of the graft include bowel obstruction, stricture, leak, perforation and enterocutaneous fistula. Lastly, vascular complications of both the venous and arterial anastomoses including stricture and pseudoaneurysm occur.

A Systematic Review of the Clinical Presentation, Diagnosis, and Treatment of Small Bowel Obstruction

PURPOSE OF REVIEW

This study aimed to systematically review small bowel obstruction (SBO), focusing on recent changes in diagnosis/therapy.

RECENT FINDINGS

SBO incidence is about 350,000/annum in the USA. Etiologies include adhesions (65%), hernias (10%), neoplasms (5%), Crohn's disease (5%), and other (15%). Bowel dilatation occurs proximal to obstruction primarily from swallowed air and secondarily from intraluminal fluid accumulation. Dilatation increases mural tension, decreases mucosal perfusion, causes bacterial proliferation, and decreases mural tensile strength that increases bowel perforation risks. Classical clinical tetrad is abdominal pain, nausea and emesis, abdominal distention, and constipation-to-obstipation. Physical exam may reveal restlessness, acute illness, and signs of dehydration and sepsis, including tachycardia, pyrexia, dry mucous membranes, hypotension/orthostasis, abdominal distention, and hypoactive bowel sounds. Severe direct tenderness, involuntary guarding, abdominal rigidity, and rebound tenderness suggest advanced SBO, as do marked leukocytosis, neutrophilia, bandemia, and lactic acidosis. Differential diagnosis includes postoperative ileus, narcotic bowel, colonic pseudo-obstruction, mesenteric ischemia, and large bowel obstruction. Medical resuscitation includes intravenous hydration, correcting electrolyte abnormalities, intravenous antibiotics, nil per os, and nasoenteral suction. Abdominal CT with oral and intravenous gastrografin contrast is highly sensitive and specific in detecting/characterizing SBO. SBO usually resolves with medical therapy but requires surgery, preferentially by laparoscopy, for unremitting total obstruction, bowel perforation, severe ischemia, or clinical deterioration with medical therapy. Overall mortality is 10% but increases to 30% with bowel necrosis/perforation. Key point in SBO is early diagnosis, emphasizing abdominal CT; aggressive medical therapy including rehydration, antibiotics, and nil per os; and surgery for failed medical therapy.

Spectrum of MDCT Findings in Bowel Obstruction in a Tertiary Care Rural Hospital in Northern India

INTRODUCTION

Multidetector Computed Tomography (MDCT) provides clinically and surgically important information in bowel obstruction. It can depict the severity, level and cause of obstruction.

AIM

To depict the spectrum of MDCT findings in cases of small and large bowel obstruction.

MATERIALS AND METHODS

Contrast enhanced MDCT examination of 50 patients were retrospectively included in the study who had evidence of clinical as well as MDCT evidence of bowel obstruction and in whom surgical/clinical follow-up for final diagnosis was available. CT scan was done in all the patients with Ingenuity CT (128 slice MDCT, Philips Medical Systems). The axial sections were reconstructed in coronal and sagital planes to determine site and cause of bowel obstruction.

RESULTS

There were 34 males and 16 females patients in this study with mean age of 28.4 years. The level of obstruction was in small bowel in 39 patients (76.67%) and large bowel in 11 patients (23.33%). Adhesive bands were the cause of Small Bowel Obstruction (SBO) in 17 patients (43.5% of SBO patients). The most common CT signs in adhesive band SBO were beak sign (seen in 70.6% patients) and fat notch sign (52.9% patients). Five cases of SBO were secondary to benign stricture. Matted adhesions were the cause of obstruction in 3 patients. All these patients showed transition zone in pelvis with positive small bowel faeces sign. Two patients with SBO due to adhesive band had evidence of closed loop obstruction with evidence of gangrenous gut on surgery. Large Bowel Obstruction (LBO) was seen in 11 patients. Most common cause of LBO was primary colonic malignancy, accounting for 7 patients (63.6%). In one patient, the cause was direct invasion of hepatic flexure by carcinoma of gall bladder. Other causes of LBO were pelvic adhesions, faecal impaction and ischaemic stricture.

CONCLUSION

SBO is more common than LBO with adhesive bands being the most common cause of SBO. MDCT is very useful for depicting site and cause of obstruction and any associated complications.