Predicting NOM Failure in Bowel Obstruction

"This study aims to collect data on patients with small bowel obstruction (SBO) admitted to hospitals in France and Italy from May 2022 to October 2024 to develop a deep convolutional neural network (DCNN) model. This model will analyze anonymized CT scans to assess the effectiveness of non-operative management (NOM) for SBO, supporting decisions on surgical intervention. Eligible patients are those diagnosed with SBO due to abdominal adhesions who initially received NOM for at least 24 hours. Patients with other SBO causes, early surgery within 24 hours, or those without a CT scan diagnosis are excluded.

Data collection spans hospitals in Antibes, Nice, Milan, and Vimercate, targeting consecutive SBO cases with adhesive etiology. To perform an external validation of the DCNN, data will also be retrospectively collected from patients admitted to the Antibes hospital between May 2021 and April 2022 with adhesive SBO. This validation set includes patients who underwent NOM successfully and those who needed surgery after NOM failure. The DCNN model will be applied to anonymized, non-contrast and contrast-enhanced portal-phase CT scans of these patients, with researchers blinded to each patient's NOM outcome to prevent bias. The model's performance will then be evaluated using accuracy metrics consistent with those used in initial model testing, ensuring the reliability of results when applied to external cases.

NOM, after adhesive SBO diagnosis via clinical exams, blood tests, and CT scans, includes fasting, analgesics, antiemetics, and fluids as per current guidelines, without necessarily using nasogastric tubes or contrast agents. Patients are re-evaluated after 24 hours to determine whether NOM should continue or if surgery is necessary. NOM is deemed effective if patients experience symptom resolution, stool passage, and no recurrence within 90 days. NOM failure is defined by the need for laparoscopic or laparotomic surgery, based on symptoms' persistence, worsening, or radiological indicators of blockage despite adequate NOM.

Data collection, registered with the French National Committee for Data Protection, includes variables like age, sex, medical history, symptoms, blood tests, CT-scan findings, NOM details, and surgical information. Radiological data, including Digital Imaging and Communication in Medicine (DICOM) files of CT scans, will be anonymized and converted to the Neuroimaging Informatics Technology Initiative (NIfTI) format for secure storage and analysis.

The NIfTI data files will be randomly split into training and test datasets in an 80%-20% ratio, processed separately for non-contrast and contrast-enhanced CT scans. Data augmentation, including random rotation, flipping, zooming, translation, and noise addition, will be applied to improve model accuracy and reduce overfitting. Different DCNN models will be trained and tested and furtherly undergo external validation to produce a tool capable of predicting NOM failure and need for surgery in patients with adhesive SBO."


Eligibility Criteria:
Inclusion Criteria:

* SBO diagnosed through clinical evaluation, blood tests, and an abdominal CT-scan performed at the admission in the Emergency Department.
* SBO secondary to single or multiple abdominal adhesions.
* Initial treatment of SBO by NOM for at least 24 hours.
* Non-opposition to the anonymous data processing by the included patients."

Exclusion Criteria:

* admission for SBO other than of adhesive etiology (hernias, bowel or other abdominal neoplasms, foreign bodies, functional obstruction, etc.).
* surgical treatment of SBO within 24 hours from admission or rather NOM duration \< 24 hours.
* SBO diagnosis performed without CT-scan."