Nomogram for Predicting the Probability of Permanent Stoma after Laparoscopic Intersphincteric Resection

Area of Science:

• Colorectal Surgery
• Surgical Oncology
• Oncologic Outcomes

Background:

• Laparoscopic intersphincteric resection (LS-ISR) is a complex procedure for ultralow rectal adenocarcinoma.
• Predicting the need for a permanent stoma is crucial for patient counseling and surgical planning.

Purpose of the Study:

• To identify risk factors associated with permanent stoma development after LS-ISR for ultralow rectal adenocarcinoma.
• To develop and validate a predictive model (nomogram) for permanent stoma probability post-LS-ISR.

Main Methods:

• A primary cohort of 301 patients undergoing LS-ISR was analyzed using multivariable logistic regression.
• Risk factors were identified, and a nomogram was constructed and validated in an independent cohort of 91 patients.
• Nomogram performance was assessed for calibration, discrimination (AUC), and clinical usefulness via decision curve analysis.

Main Results:

• The permanent stoma rate was 11.3% in the primary cohort and 18.7% in the validation cohort.
• Independent risk factors for permanent stoma included neoadjuvant chemoradiotherapy (nCRT), ASA score of 3, distant metastasis, and anastomotic leakage.
• The nomogram demonstrated strong predictive performance with AUCs of 0.842 and 0.858 in the primary and validation cohorts, respectively, and showed good calibration and clinical utility.

Conclusions:

• A validated nomogram effectively predicts the risk of permanent stoma in patients with ultralow rectal adenocarcinoma undergoing LS-ISR.
• This tool aids surgeons in identifying high-risk patients, facilitating informed decision-making and preoperative counseling.