Diabetes Mellitus in Patients Presenting with Adhesive Small Bowel Obstruction: Delaying Surgical Intervention Results in Worse Outcomes

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

OBJECTIVE

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

SUMMARY BACKGROUND DATA

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Diseño y validación de una herramienta para la predicción de desenlaces adversos en pacientes con obstrucción intestinal por bridas: La escala HALVIC

Introducción. La obstrucción intestinal por bridas representa una causa común de consulta a los servicios de urgencias, pero hay poca claridad sobre qué pacientes tienen mayor riesgo de desarrollar complicaciones. El objetivo de este estudio fue diseñar y validar una escala de predicción de riesgo de desenlaces adversos en pacientes con obstrucción intestinal por bridas. Métodos. Estudio de cohorte retrospectivo realizado a partir de la base de datos MIMIC-IV. Se incluyeron pacientes adultos admitidos al servicio de urgencias entre 2008 y 2019, con diagnóstico de obstrucción intestinal por bridas. El desenlace principal fue el compuesto de resección intestinal, ingreso a unidad de cuidados intensivos y mortalidad por cualquier causa. Se diseñó una escala de predicción de riesgo asignando un puntaje a cada variable. Resultados. Se incluyeron 513 pacientes, 63,7 % hombres. El desenlace compuesto se presentó en el 25,7 % de los casos. La edad, historia de insuficiencia cardiaca y enfermedad arterial periférica, nivel de hemoglobina, recuento de leucocitos e INR constituyeron el mejor modelo de predicción de estos desenlaces (AUC 0,75). A partir de este modelo, se creó la escala simplificada HALVIC, clasificando el riesgo del desenlace compuesto en bajo (0-2 puntos), medio (3-4 puntos) y alto (5-7 puntos). Conclusión. La escala HALVIC es una herramienta de predicción simple y fácilmente aplicable. Puede identificar de manera precisa los pacientes con obstrucción intestinal por bridas con alto riesgo de complicaciones, permitiendo el ajuste individualizado de las estrategias de manejo para mejorar los desenlaces.

Hyperglycaemia and the risk of post-surgical adhesion

Post-surgical adhesions are a major complication leading to organ dysfunctions, pain, intestinal obstruction, and infertility. The incidence of post-surgical adhesion is really high. The factors involved in the pathogenesis of post-surgical fibrosis, are largely unknown, for example why two patients with similar abdominal operation have a different risks of adhesion severity? High secretion of pro-inflammatory cytokines and growth factors, includes tumour necrosis factor α (TNF-α), interleukin 6 (IL6), and transforming growth factor β (TGF-β) by persistent recruitment of immune cells and the inappropriate proliferated fibroblast/mesothelial cells can stimulate signalling pathways particularly TGF-β leads to the up-regulation of some pro-fibrotic genes that impair fibrinolytic activity and promote extracellular matrix (ECM) accumulation. In this review, we focus on the role of diabetes and hyperglycaemia on post-surgical fibrosis, including the molecular mechanisms affected by hyperglycaemia that cause inflammation, oxidative stress, and increase the expression of pro-fibrotic molecules.

Use of matching methods in observational studies with critical patients and renal outcomes. Scoping review

Introduction: The use of matching techniques in observational studies has been increasing and is not always used appropriately. Clinical experiments are not always feasible in critical patients with renal outcomes, and observational studies are an important alternative. Objective: Through a scoping review, determine the available evidence on the use of matching methods in studies involving critically ill patients and assessing renal outcomes. Methods: Medline, Embase, and Cochrane databases were used to identify articles published between 1992 and 2020 up to week 10, which studied different exposures in the critically ill patient with renal outcomes and used propensity matching methods. Results: Most publications are cohort studies 94 (94. 9 %), five studies (5. 1 %) were cross-sectional. The main pharmacological intervention was the use of antibiotics in seven studies (7. 1%) and the main risk factor studied was renal injury prior to ICU admission in 10 studies (10. 1%). The balance between the baseline characteristics assessed by standardized means, in only 28 studies (28. 2%). Most studies 95 (96 %) used logistic regression to calculate the propensity index. Conclusion: Major inconsistencies were observed in the use of methods and in the reporting of findings. A summary is made of the aspects to be considered in the use of the methods and reporting of the findings with the matching by propensity index.

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.

Bologna guidelines for diagnosis and management of adhesive small bowel obstruction (ASBO): 2017 update of the evidence-based guidelines from the world society of emergency surgery ASBO working group

Background

Adhesive small bowel obstruction (ASBO) is a common surgical emergency, causing high morbidity and even some mortality. The adhesions causing such bowel obstructions are typically the footprints of previous abdominal surgical procedures. The present paper presents a revised version of the Bologna guidelines to evidence-based diagnosis and treatment of ASBO. The working group has added paragraphs on prevention of ASBO and special patient groups.

Methods

The guideline was written under the auspices of the World Society of Emergency Surgery by the ASBO working group. A systematic literature search was performed prior to the update of the guidelines to identify relevant new papers on epidemiology, diagnosis, and treatment of ASBO. Literature was critically appraised according to an evidence-based guideline development method. Final recommendations were approved by the workgroup, taking into account the level of evidence of the conclusion.

Recommendations

Adhesion formation might be reduced by minimally invasive surgical techniques and the use of adhesion barriers. Non-operative treatment is effective in most patients with ASBO. Contraindications for non-operative treatment include peritonitis, strangulation, and ischemia. When the adhesive etiology of obstruction is unsure, or when contraindications for non-operative management might be present, CT is the diagnostic technique of choice. The principles of non-operative treatment are nil per os, naso-gastric, or long-tube decompression, and intravenous supplementation with fluids and electrolytes. When operative treatment is required, a laparoscopic approach may be beneficial for selected cases of simple ASBO.Younger patients have a higher lifetime risk for recurrent ASBO and might therefore benefit from application of adhesion barriers as both primary and secondary prevention.

Discussion

This guideline presents recommendations that can be used by surgeons who treat patients with ASBO. Scientific evidence for some aspects of ASBO management is scarce, in particular aspects relating to special patient groups. Results of a randomized trial of laparoscopic versus open surgery for ASBO are awaited.

Operative versus non-operative management of adhesive small bowel obstruction: A systematic review and meta-analysis

OBJECTIVES

To investigate outcomes of operative and non-operative management of adhesive small bowel obstruction (SBO).

METHODS

We performed a systematic review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement standards. We conducted a search of electronic information sources to identify all randomised controlled trials (RCTs) and observational studies investigating outcomes of operative versus non-operative management of patients with adhesive SBO. We used the Cochrane risk of bias tool and the Newcastle-Ottawa scale to assess the risk of bias of RCTs and observational studies, respectively. Fixed-effect or random-effects models were applied to calculate pooled outcome data.

RESULTS

We found one RCT, two prospective and three retrospective observational studies, enrolling a total of 876 patients. The analyses showed that operative management of adhesive SBO was associated with a lower risk of future recurrence [odds ratio (OR) 0.54, 95% confidence interval (CI) 0.38-0.76, P = 0.0005] but a higher risk of mortality [risk difference (RD) 0.03, 95% CI 0.01-0.06, P = 0.01] and complications (OR 5.39, 95% CI 2.97-9.78, P < 0.00001). There was no difference in need for surgical re-intervention rate (OR 0.72, 95% CI 0.35-1.47, P = 0.36) and length of stay [mean difference (MD) 5.07, 95% CI -2.36-12.49, P = 1.0] between operative and non-operative managements. The baseline suspicion of strangulation was a major confounding factor. When the baseline suspicion of strangulation was higher in the operative group, the risk of mortality (RD 0.04, 95% CI 0.02-0.07, P = 0.0006) and complications (OR 8.14, 95% CI 4.16-15.94, P = 0.00001) were higher in the operative group but the risk of recurrence was lower (OR 0.62, 95% CI 0.43-0.90, P = 0.01). When the baseline suspicion of strangulation was low in both groups, there was no difference in any of the outcomes except recurrence (OR 0.09, 95% CI 0.02-0.37, P = 0.0009) which was lower in the operative group.

CONCLUSIONS

The difference in baseline suspicion of strangulation between operative and non-operative groups is a major confounding factor in current literature. The benefit of surgical treatment should be balanced with the risks associated with surgery, patient's co-morbidities, and presence or absence of strangulation. Based on the best available evidence it could be argued that surgical intervention could be preserved for cases with high suspicion or evidence of bowel strangulation. The controversy still remains for optimum length of conservative management and timing of surgery (early or late) for cases with low baseline suspicion of strangulation. Randomised controlled trials are required to compare outcomes of early operation (<24 h) versus late operation (>24 h) and early operation versus conservative management in patients with low suspicion of strangulation.