A multi-institution prospective observational study of small bowel obstruction: Clinical and computerized tomography predictors of which patients may require early surgery

Prognostic factors to identify resolution of small bowel obstruction without need for operative management: systematic review

OBJECTIVES

To identify imaging, clinical, and laboratory variables potentially prognostic for surgical management of small bowel obstruction.

METHODS

Two researchers systematically reviewed indexed literature 2001-2021 inclusive for imaging, clinical, and laboratory variables potentially predictive of surgical management of small bowl obstruction and/or ischaemia at surgery, where performed. Risk of bias was assessed. Contingency tables for variables reported in at least 5 studies were extracted and meta-analysed to identify strong evidence of association with clinical outcomes, across studies.

RESULTS

Thirty-one studies were ultimately included, reporting 4638 patients (44 to 313 per study). 11 (35%) studies raised no risk of bias concerns. CT was the modality reported most (29 studies, 94%). Meta-analysis of 21 predictors identified 5 strongly associated with surgical intervention, 3 derived from CT (peritoneal free fluid, odds ratio [OR] 3.24, 95%CI 2.45 to 4.29; high grade obstruction, OR 3.58, 95%CI 2.46 to 5.20; mesenteric inflammation, OR 2.61, 95%CI 1.94 to 3.50; abdominal distension, OR 2.43, 95%CI 1.34 to 4.42; peritonism, OR 3.97, 95%CI 2.67 to 5.90) and one with conservative management (previous abdominopelvic surgery, OR 0.58, 95%CI 0.40 to 0.85). Meta-analysis of 10 predictors identified 3 strongly associated with ischaemia at surgery, 2 derived from CT (peritoneal free fluid, OR 3.49, 95%CI 2.28 to 5.35; bowel thickening, OR 3.26 95%CI 1.91 to 5.55; white cell count, OR 4.76, 95%CI 2.71 to 8.36).

CONCLUSIONS

Systematic review of patients with small bowel obstruction identified four imaging, three clinical, and one laboratory predictors associated strongly with surgical intervention and/or ischaemia at surgery.

CLINICAL RELEVANCE STATEMENT

Via systematic review and meta-analysis, we identified imaging, clinical, and laboratory predictors strongly associated with surgical management of small bowel obstruction and/or ischaemia. Multivariable model development to guide management should incorporate these since they display strong evidence of potential utility.

KEY POINTS

• While multivariable models incorporating clinical, laboratory, and imaging factors could predict surgical management of small bowel obstruction, none are used widely. • Via systematic review and meta-analysis we identified imaging, clinical, and laboratory variables strongly associated with surgical management and/or ischaemia at surgery. • Development of multivariable models to guide management should incorporate these predictors, notably CT scanning, since they display strong evidence of potential utility.

Survey of Diagnostic and Management Practices in Small Bowel Obstruction: Individual and Generational Variation Despite Practice Guidelines

Background: Small bowel obstruction (SBO) is a common disorder managed by surgeons. Despite extensive publications and management guidelines, there is no universally accepted approach to its diagnosis and management. We conducted a survey of acute care surgeons to elucidate their SBO practice patterns.Methods: A self-report survey of SBO diagnosis and management practices was designed and distributed by email to AAST surgeons who cared for adult SBO patients. Responses were analyzed with descriptive statistics and Chi-square test of independence at α = .05.Results: There were 201 useable surveys: 53% ≥ 50 years, 77% male, 77% at level I trauma centers. Only 35.8% reported formal hospital SBO management guidelines. Computed tomography (CT) scan was the only diagnostic exam listed as "essential" by the majority of respondents (82.6%). Following NG decompression, 153 (76.1%) would "always/frequently" administer a water-soluble contrast challenge (GC). There were notable age differences in approach. Compared to those ≥50 years, younger surgeons were less likely to deem plain abdominal films as "essential" (16.0% vs 40.2%; P < .01) but more likely to require CT scan (88.3% vs 77.6%; P = .045) for diagnosis and to "always/frequently" administer GC (84.0% vs 69.2%; P < .01). Younger surgeons used laparoscopy "frequently" more often than older surgeons (34.0% vs 21.5%, P = .05).Discussion: There is significant variation in diagnosis and management of SBO among respondents in this convenience sample, despite existing PMGs. Novel age differences in responses were observed, which prompts further evaluation. Additional research is needed to determine whether variation in practice patterns is widespread and affects outcomes.

A multi-analysis of nomogram model for the identification of banded adhesions and matted adhesions in adhesive small bowel obstruction

BACKGROUND

Preoperative diagnosis of the cause of adhesive small bowel obstruction (ASBO) is very challenging for surgeons. We aimed to develop a nomogram model for the identification of banded adhesions (BA) and matted adhesions (MA) of ASBO.

METHODS

This retrospective study enrolled patients with ASBO between January 2012 and December 2020, classified into BA and MA groups according to the intraoperative findings. A nomogram model was developed by using multivariable logistic regression analysis.

RESULTS

A total of 199 patients were included, with 117 (58.8%) cases of BA and 82 (41.2%) cases of MA. There were 150 patients designed for training the model, and the other 49 cases for validation. Multivariate logistic regression analysis showed that prior surgery for once (p = 0.008), white blood cells (WBC) (p = 0.001), beak sign (p < 0.001), fat notch sign (p = 0.013), and mesenteric haziness (p = 0.005) were independently associated with BA. The AREA under the receiver operating characteristic curve (AUC-ROC) of the nomogram model in the training and validation sets were 0.861 (95% CI 0.802-0.921) and 0.884 (95% CI 0.789-0.980), respectively. The calibration plot demonstrated a good agreement. A decision curve analysis demonstrated that the nomogram model was clinically useful.

CONCLUSIONS

The multi-analysis of the nomogram model might have a favorable clinical applicability for the identification of BA and MA in patients with adhesive small bowel obstruction.

Individualization of the best approach for adhesive small bowel obstruction

BACKGROUND

Laparoscopic postoperatives outcomes in adhesiolysis are promising but conversion and morbidity remains high. The objective of our study was to determine preoperative factors to individualize and select the most appropriate approach for each patient.

METHODS

Patients ≥18 years old undergoing emergent surgery for adhesive small bowel obstruction and internal hernias were evaluated. Bivariate and multivariate analysis were performed to investigate factors related to conversion to open surgery and to the type of adhesions.

RESULTS

Of 333 patients, 224 were operated by laparotomy and 109 by laparoscopy (conversion rate: 40%). Previous abdominal wall mesh, type of adhesions, bowel lesion, need for intestinal resection and laparoscopic skills were statistically related to conversion. In the multivariate analysis, complex adhesions (OR 4.3, 95% CI 1.5-12.2; P = 0.006), the need for intestinal resection (OR 14.16, 95% CI 2.55-78.68; P = 0.002), and non-advanced laparoscopy surgeons (OR 4.31, 95% CI 1.56-11.94; P = 0.005) were independent factors for conversion to open surgery. ASA III-IV, previous surgeries, previous abdominal mesh and previous adhesiolysis were related to complex adhesions. Previous laparoscopic surgery and internal hernia or closed loop in computed tomography were associated with simple adhesions as a cause of the obstruction. In the multivariate, previous adhesiolysis (OR 4.76, 95% CI 1.23-18.3; P = 0.023) and the findings on computed tomography were significantly related with the type of adhesion.

CONCLUSION

Some preoperative factors allow to individualize the surgical approach in the adhesive small bowel obstruction improving surgical outcomes.

Predictors for success of non-operative management of adhesive small bowel obstruction

BACKGROUND

Majority of adhesive small bowel obstruction (SBO) cases can be managed non-operatively. However, a proportion of patients failed non-operative management.

AIM

To evaluate the predictors of successful non-operative management in adhesive SBO.

METHODS

A retrospective study was performed for all consecutive cases of adhesive SBO from November 2015 to May 2018. Data collated included basic demographics, clinical presentation, biochemistry and imaging results and management outcomes. The imaging studies were independently analyzed by a radiologist who was blinded to the clinical outcomes. The patients were divided into group A operative (including those that failed initial non-operative management) and group B non-operative for analysis.

RESULTS

Of 252 patients were included in the final analysis; group A (n = 90) (35.7%) and group B (n = 162) (64.3%). There were no differences in the clinical features between both groups. Laboratory tests of inflammatory markers and lactate levels were similar in both groups. From the imaging findings, the presence of a definitive transition point [odds ratio (OR) = 2.67, 95% confidence interval (CI): 0.98-7.32, P = 0.048], presence of free fluid (OR = 2.11, 95%CI: 1.15-3.89, P = 0.015) and absence of small bowel faecal signs (OR = 1.70, 95%CI: 1.01-2.88, P = 0.047) were predictive of the need of surgical intervention. In patients that received water soluble contrast medium, the evidence of contrast in colon was 3.83 times predictive of successful non-operative management (95%CI: 1.79-8.21, P = 0.001).

CONCLUSION

The computed tomography findings can assist clinicians in deciding early surgical intervention in adhesive SBO cases that are unlikely to be successful with non-operative management to prevent associated morbidity and mortality.

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.

Point-of-care ultrasound-first for the evaluation of small bowel obstruction: National cost savings, length of stay reduction, and preventable radiation exposure

OBJECTIVES

Computed tomography (CT) has long been the gold standard in diagnosing patients with suspected small bowel obstruction (SBO). Recently, point-of-care ultrasound (POCUS) has demonstrated comparable test characteristics to CT imaging for the diagnosis of SBO. Our primary objective was to estimate the annual national cost saving impact of a POCUS-first approach for the evaluation of SBO. Our secondary objectives were to estimate the reduction in radiation exposure and emergency department (ED) length of stay (LOS).

METHODS

We created and ran 1000 trials of a Monte Carlo simulation. The study population included all patients presenting to the ED with abdominal pain who were diagnosed with SBO. Using this simulation, we modeled the national annual cost savings in averted advanced imaging from a POCUS-first approach for SBO. The model assumes that all patients who require surgery or have non-diagnostic POCUS exams undergo CT imaging. The model also conservatively assumes that a subset of patients with diagnostic POCUS exams undergo additional confirmatory CT imaging. We used the same Monte Carlo model to estimate the reduction in radiation exposure and total ED bed hours saved.

RESULTS

A POCUS-first approach for diagnosing SBO was estimated to save a mean (±SD) of $30.1 million (±8.9 million) by avoiding 143,000 (±31,000) CT scans. This resulted in a national cumulative decrease of 507,000 bed hours (±268,000) in ED LOS. The reduction in radiation exposure to patients could potentially prevent 195 (±56) excess annual cancer cases and 98 (±28) excess annual cancer deaths.

CONCLUSIONS

If adopted widely and used consistently, a POCUS-first algorithm for SBO could yield substantial national cost savings by averting advanced imaging, decreasing ED LOS, and reducing unnecessary radiation exposure in patients. Clinical decision tools are needed to better identify which patients would most benefit from CT imaging for SBO in the ED.

Adhesive Small Bowel Obstruction and the six w's: Who, How, Why, When, What, and Where to diagnose and operate?

BACKGROUND AND AIMS

Approximately 75% of patients admitted with small bowel obstruction have intra-abdominal adhesions as their cause (adhesive small bowel obstruction). Up to 70% of adhesive small bowel obstruction cases, in the absence of strangulation and bowel ischemia, can be successfully treated with conservative management. However, emerging evidence shows that surgery performed early during the first episode of adhesive small bowel obstruction is highly effective. The objective of this narrative review is to summarize the current evidence on adhesive small bowel obstruction management strategies.

MATERIALS AND METHODS

A review of the literature published over the last 20 years was performed to assess Who, hoW, Why, When, What, and Where diagnose and operate on patients with adhesive small bowel obstruction.

RESULTS

Adequate patient selection through physical examination and computed tomography is the key factor of the entire management strategy, as failure to detect patients with strangulated adhesive small bowel obstruction and bowel ischemia is associated with significant morbidity and mortality. The indication for surgical exploration is usually defined as a failure to pass contrast into the ascending colon within 8-24 h. However, operative management with early adhesiolysis, defined as operative intervention on either the calendar day of admission or the calendar day after admission, has recently shown to be associated with an overall long-term survival benefit compared to conservative management. Regarding the surgical technique, laparoscopy should be used only in selected patients with an anticipated single obstructing band, and there should be a low threshold for conversion to an open procedure in cases of high risk of bowel injuries.

CONCLUSION

Although most adhesive small bowel obstruction patients without suspicion of bowel strangulation or gangrene are currently managed nonoperatively, the long-term outcomes following this approach need to be analyzed in a more exhaustive way, as surgery performed early during the first episode of adhesive small bowel obstruction has shown to be highly effective, with a lower rate of recurrence.

Bowel Ischemia Score Predicts Early Operation in Patients With Adhesive Small Bowel Obstruction

BACKGROUND

Nonoperative management of adhesive small bowel obstruction (SBO) is successful in up to 80% of patients. Current recommendations advocate for computed tomography (CT) scan in all patients with SBO to supplement surgical decision-making. The hypothesis of this study was that cumulative findings on CT would predict the need for operative intervention in the setting of SBO.

METHODS

This is an analysis of a retrospectively and prospectively collected adhesive SBO database over a 6-year period. A Bowel Ischemia Score (BIS) was developed based on the Eastern Association for the Surgery of Trauma guidelines of CT findings suggestive of bowel ischemia. One point was assigned for each of the six variables. Early operation was defined as surgery within 6 hours of CT scan.

RESULTS

Of the 275 patients in the database, 249 (90.5%) underwent CT scan. The operative rate was 28.3% with a median time from CT to operation of 21 hours (Interquartile range 5.2-59.2 hours). Most patients (166/217, 76.4%) with a BIS of 0 or 1 were successfully managed nonoperatively, whereas the majority of those with a BIS of 3 required operative intervention (5/6, 83.3%). The discrimination (area under the receiver operating characteristic curve) of BIS for early surgery, any operative intervention, and small bowel resection were 0.83, 0.72, and 0.61, respectively.

CONCLUSION

The cumulative signs of bowel ischemia on CT scan represented by BIS, rather than the presence or absence of any one finding, correlate with the need for early operative intervention.

Clinical Outcome and Predictors of Intestinal Obstruction Surgery in Ethiopia: A Cross-Sectional Study

Background

Despite the advancement in the healthcare system, the impact of surgical interventions on public health systems will continue to grow. But predicting the outcome is challenging. Concerns related to unexpected outcomes and delays in the diagnosis of postoperative complications are the major issue. Intestinal obstruction is a common life-threatening surgical condition followed by fatal and nonfatal postoperative complications. This study was aimed at assessing results after surgery for intestinal obstruction in a hospital of Ethiopia. Methodology. An institutional-based cross-sectional study was conducted among 254 postoperative patients admitted with intestinal obstruction from January 1, 2014, to December 31, 2017. Data were coded and entered into EpiData 4.2.0.0 software and exported to the Statistical Package for the Social Sciences version 22 for analysis. A binary logistic regression model was used for analysis. All variables with a p value < 0.25 during bivariable analysis were considered for multivariable logistic regression analysis.

Results

The magnitude of poor surgical outcome of intestinal obstruction was 21.3% for patients enrolled into this investigation. The age group of ≥55 years (adjusted odds ratio (AOR) = 2.9, 95% CI: 1.03, 8.4), duration of illness of ≥24 hrs (AOR = 3.1, 95% CI: 1.03, 9.4), preoperative diagnosis of a gangrenous large bowel (AOR = 3.6, 95% CI: 1.3, 9.8), and a gangrenous small bowel (AOR = 4.2, 95% CI: 1.3, 13.7) were significantly associated with poor surgical outcome.

Conclusions

The magnitude of poor surgical outcome was high. Age, late presentation of illness, and gangrenous bowel obstructions were significantly associated with poor outcomes. So, concern should be given in early detection and follow-up of patients who came late and older patients.

ACR Appropriateness Criteria® Suspected Small-Bowel Obstruction

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

Diagnostic 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 Safety of Expectant Management for Adhesive Small Bowel Obstruction: A Systematic Review

BACKGROUND

Surgical training has long been to "never let the sun set on a bowel obstruction" without an operation to rule out and/or treat compromised bowel. However, advances in diagnostics have called into question the appropriate timing of non-emergent operations and expectant management is increasingly used. We performed a systematic review to evaluate the safety and effectiveness of expectant management for adhesive small bowel obstruction (aSBO) compared to early, non-emergent operation.

MATERIALS & METHODS

We queried PubMed, EMBASE, and Cochrane databases for studies (1990-present) comparing early, non-emergent operations and expectant management for aSBO (PROSPERO #CRD42017057676).

RESULTS

Of 4873 studies, 29 cohort studies were included for full-text review. Four studies directly compared early surgery with expectant management, but none excluded patients who underwent emergent operations from those having early non-emergent surgery, precluding a direct comparison of the two treatment types of interest. When aggregated, the rate of bowel resection was 29% in patients undergoing early operation vs. 10% in those undergoing expectant management. The rate of successful, non-operative management in the expectant group was 58%. There was a 1.3-day difference in LOS favoring expectant management (LOS 9.7 vs. 8.4 days), and the rate of death was 2% in both groups.

CONCLUSION

Despite the shift towards expectant management of aSBO, no published studies have yet compared early, non-emergent operation and expectant management. A major limitation in evaluating the outcomes of these approaches using existing studies is confounding by indication related to including patients with emergent indications for surgery on admission in the early operative group. A future study, randomizing patients to early non-emergent surgery or expectant management, should inform the comparative safety and value of these approaches.

Application of the AAST EGS Grade for Adhesive Small Bowel Obstruction to a Multi-national Patient Population

BACKGROUND

The American Association for the Surgery of Trauma (AAST) anatomic severity grading system for adhesive small bowel obstruction (ASBO) has demonstrated to be a valid tool in North American patient populations. Using a multi-national patient cohort, we retrospectively assessed the validity the AAST ASBO grading system and estimated disease severity in a global population in order to correlate with several key clinical outcomes.

METHODS

Multicenter retrospective review during 2012-2016 from four centers, Minnesota USA, Bologna Italy, Pietermaritzburg South Africa, and Bucharest Romania, was performed. Adult patients (age ≥ 18) with ASBO were identified. Baseline demographics, physiologic parameters, laboratory results, operative and imaging details, outcomes were collected. AAST ASBO grades were assigned by independent reviewers. Univariate and multivariable analyses with odds ratio (OR) and 95% confidence intervals (CIs) were performed.

RESULTS

There were 789 patients with a median [IQR] age of 58 [40-75] years; 47% were female. The AAST ASBO grades were I (n = 180, 23%), II (n = 443, 56%), III (n = 87, 11%), and IV (n = 79, 10%). Successful non-operative management was 58%. Conversion rate from laparoscopy to laparotomy was 33%. Overall mortality and complication and temporary abdominal closure rates were 2, 46, and 4.7%, respectively. On regression, independent predictors for mortality included grade III (OR 4.4 95%CI 1.1-7.3), grade IV (OR 7.4 95%CI 1.7-9.4), pneumonia (OR 5.6 95%CI 1.4-11.3), and failing non-operative management (OR 2.4 95%CI 1.3-6.7).

CONCLUSION

The AAST EGS grade can be assigned with ease at any surgical facility using operative or imaging findings. The AAST ASBO severity grading system has predictive validity for important clinical outcomes and allows for standardization across institutions, providers, and future research. Disease severity and outcomes varied between countries.

LEVEL OF EVIDENCE III

Study type Retrospective multi-institutional cohort study.

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.

Volvulus

Intestinal volvulus, regardless of location, is a rare disease process, but one that requires high suspicion and timely diagnosis given the increased incidence of intestinal necrosis and potential mortality. Most patients with intestinal volvulus require some form of surgical intervention. However, over the last few decades, the work-up and management of intestinal volvulus has changed given constant advancements in technology and patient care. Most importantly, however, is recognizing the need for emergent versus more elective surgery because this influences the morbidity and mortality for the individual patient.

Current management of small bowel obstruction in the UK: results from the National Audit of Small Bowel Obstruction clinical practice survey

AIM

Small bowel obstruction (SBO) is associated with high rates of morbidity and mortality. The National Audit of Small Bowel Obstruction (NASBO) is a collaboration between trainees and specialty associations to improve the care of patients with SBO through national clinical audit. The aim of this study was to define current consultant practice preferences in the management of SBO in the UK.

METHOD

A survey was designed to assess practice preferences of consultant surgeons. The anonymous survey captured demographics, indications for surgery or conservative management, use of investigations including water-soluble contrast agents (WSCA), use of laparoscopy and nutritional support strategies. The questionnaire underwent two pilot rounds prior to dissemination via the NASBO network.

RESULTS

A total of 384 responses were received from 131 NASBO participating units (overall response rate 29.2%). Abdominal CT and serum urea and electrolytes were considered essential initial investigations by more than 80% of consultants. Consensus was demonstrated on indications for early surgery and conservative management. Three hundred and thirty-eight (88%) respondents would consider use of WSCA; of these, 328 (97.1%) would use it in adhesive SBO. Two hundred (52.1%) consultants considered a laparoscopic approach when operating for SBO. Oral nutritional supplements were favoured in operatively managed patients by 259 (67.4%) respondents compared with conservatively managed patients (186 respondents, 48.4%).

CONCLUSION

This survey demonstrates consensus on imaging requirements and indications for early surgery in the management of SBO. Significant variation exists around awareness of the need for nutritional support in patients with SBO, and on strategies to achieve this support.

Association between Abdominal Free Fluid and Postoperative Complications and Mortality in Patients with Small-Bowel Obstruction

BACKGROUND AND AIMS:

Small-bowel obstruction is a frequent cause of hospitalization. The condition is potentially life-threatening, causing many admission days and is a heavy burden socioeconomically. Patients with small-bowel obstruction may develop abdominal free fluid and the quality of this fluid may be predictive of worse outcomes. Our aim was to examine whether the presence of free fluid and its density, measured on computed tomography scans, was associated with severe complications and mortality postoperatively.

MATERIALS AND METHODS:

Patients admitted to the Department of Surgery, Zealand University Hospital with a diagnosis of small-bowel obstruction between January 2010 and December 2015 were included. Medical records were reviewed and preoperative computed tomography scans were examined. A radiologist blinded to the outcomes reviewed all Hounsfield unit values of the free fluid. The primary outcomes evaluated were odds ratios of the severity of complications and hazard ratios of 30- and 90-day mortality postoperatively.

RESULTS:

A total of 289 patients were included. Analyses revealed an adjusted odds ratio of 1.03 (95%confidence interval = 0.93-1.15) between the presence of free fluid and postoperative complications and an adjusted hazard ratio of 1.28 (95% confidence interval =  0.80-2.05, p = 0.30) of the 30-day mortality in this patient group. Furthermore, the analyses revealed an adjusted odds ratio of 1.22 (95% confidence interval 0.98-1.52) between the density of the free fluid > 20 Hounsfield unit and postoperative complications and an adjusted hazard ratio of 0.85 (95% confidence interval =  0.28-2.63, p = 0.78) of the 30-day mortality.

CONCLUSION:

No significant correlation was found between the presence of free fluid nor its density in regard to postoperative complications or mortality in patients with small-bowel obstruction.

Current management of adhesive small bowel obstruction

Small bowel obstruction is a common and significant surgical presentation. Approximately 30% of presentations will require surgery during admission. The great challenge of adhesive small bowel obstruction (ASBO) management is the early detection of silent intestinal ischaemia in patients initially deemed suitable for conservative therapy. Recent literature emphasizes the effectiveness of computed tomography enterography and water-soluble contrast studies in the management of ASBO. Low-volume undiluted water-soluble contrast has been shown to have both triage and therapeutic value in the management of ASBO. Their use has been demonstrated to reduce the need for surgery to below 20%. There has also been growing interest in clinicoradiological algorithms which aim to predict ischaemia early in the course of presentation. The aim of this review is to summarize the latest evidence and clarify previous uncertainties, specifically regarding the duration of conservative treatment, timing of contrast studies and the reliability of predictive algorithms. Based on this latest evidence, we have formulated a management protocol which aims to integrate these latest developments and formalize a strategy for best management in ASBO.

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.

Surgeon attitudes and practice patterns in managing small bowel obstruction: a qualitative analysis

BACKGROUND

Historical training instructs surgeons to, "never let the sun set on a small bowel obstruction (SBO)" due to concern for bowel ischemia. However, the routine use of computed tomography scans for ruling out ischemia provides the opportunity for trial of nonoperative management, allowing time for resolution of adhesive SBO. In light of advances in practice, little is known about how surgeons manage these patients, in particular, whether there is consistency in the stated duration for safe nonoperative management.

METHODS

Using a case vignette (a patient with computed tomography scan diagnosed complete SBO without bowel ischemia), we interviewed a purposive sample of general surgeons practicing in Washington State to understand stated approaches to clinical management. Interview questions addressed typical practice, preferred timing of surgery, and approach. We conducted a content analysis to understand current practice and attitudes.

RESULTS

We interviewed 15 surgeons practicing across Washington State. Surgical practice patterns for patients with SBO varied widely. The period of time that surgeons were willing to manage patients nonoperatively ranged from 1-7 d. Interviews revealed insight into surgical decision-making, the importance of patient preferences, variation in practice, and evidence gaps. All surgeons acknowledged a lack of evidence to support appropriate management of patients with SBO.

CONCLUSIONS

Interviews with practicing surgeons highlight a changing paradigm away from routine early surgery for patients with adhesive SBO. However, there is lack of consensus in the appropriate duration of nonoperative management and practices vary considerably. These revealed attitudes inform the feasibility and design of future randomized studies of patients with adhesive SBO.

High-Density Free Fluid on Computed Tomography: a Predictor of Surgical Intervention in Patients with Adhesive Small Bowel Obstruction

BACKGROUND

Patients with adhesive small bowel obstruction (ASBO) often develop intraabdominal free fluid (IFF). While IFF is a finding on abdominopelvic computed tomography (CT) associated with the need for surgical intervention, many patients with IFF can be still managed non-operatively. A previous study suggested that a higher red blood cell count of IFF is highly predictive of strangulated ASBO. We hypothesized that radiodensity in IFF (Hounsfield unit (HU)) on CT would predict the need for surgical intervention.

STUDY DESIGN

Patients with clinicoradiological evidence of ASBO between January 2009 and December 2013 were identified. In patients with IFF > 3 cm² identified on CT, the HU was measured in the largest pocket of IFF. A sensitivity analysis was performed to determine a high-density HU threshold. The HU of patients who underwent therapeutic laparotomy was compared with those successfully discharged with non-operative management.

RESULTS

A total of 318 patients with ASBO (median age 52 years, 56.0 % male) were identified. Of 111 patients who had IFF on CT, 55.9 % underwent therapeutic laparotomy and 15.3 % required bowel resection. Radiodensity of IFF in the operative group was significantly higher than that in the non-operative group (18.2 vs. 7.0 HU, p < 0.01). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of high-density IFF (>10 HU) to predict the need for surgical intervention were 83.9, 65.3, 75.4, 76.2, and 75.6 %, respectively.

CONCLUSIONS

High-density IFF on CT was significantly associated with the need for surgical intervention in patients with ASBO. Prospective study to validate the predictive value of high-density IFF on CT will be warranted.