Anastomotic leaks: technique and timing of detection

Establishing and clinically validating a machine learning model for predicting unplanned reoperation risk in colorectal cancer

BACKGROUND

Colorectal cancer significantly impacts global health, with unplanned reoperations post-surgery being key determinants of patient outcomes. Existing predictive models for these reoperations lack precision in integrating complex clinical data.

AIM

To develop and validate a machine learning model for predicting unplanned reoperation risk in colorectal cancer patients.

METHODS

Data of patients treated for colorectal cancer (n = 2044) at the First Affiliated Hospital of Wenzhou Medical University and Wenzhou Central Hospital from March 2020 to March 2022 were retrospectively collected. Patients were divided into an experimental group (n = 60) and a control group (n = 1984) according to unplanned reoperation occurrence. Patients were also divided into a training group and a validation group (7:3 ratio). We used three different machine learning methods to screen characteristic variables. A nomogram was created based on multifactor logistic regression, and the model performance was assessed using receiver operating characteristic curve, calibration curve, Hosmer-Lemeshow test, and decision curve analysis. The risk scores of the two groups were calculated and compared to validate the model.

RESULTS

More patients in the experimental group were ≥ 60 years old, male, and had a history of hypertension, laparotomy, and hypoproteinemia, compared to the control group. Multiple logistic regression analysis confirmed the following as independent risk factors for unplanned reoperation (P < 0.05): Prognostic Nutritional Index value, history of laparotomy, hypertension, or stroke, hypoproteinemia, age, tumor-node-metastasis staging, surgical time, gender, and American Society of Anesthesiologists classification. Receiver operating characteristic curve analysis showed that the model had good discrimination and clinical utility.

CONCLUSION

This study used a machine learning approach to build a model that accurately predicts the risk of postoperative unplanned reoperation in patients with colorectal cancer, which can improve treatment decisions and prognosis.

"Relaparoscopy" to treat early complications following colorectal surgery

BACKGROUND

Laparoscopic surgery has shown clear benefits that could also be useful in the emergency setting such as early reoperations after colorectal surgery. The aim of this study was to evaluate the safety and feasibility of laparoscopic reintervention ("relaparoscopy") (RL) to manage postoperative complications after laparoscopic colorectal surgery.

METHODS

We performed a retrospective study based on a prospectively collected database from 2000 to 2019. Patients who required a reoperation after undergoing laparoscopic colorectal surgery were included. According to the approach used at the reoperation, the cohort was divided in laparoscopy (RL) and laparotomy (LPM). Demographics, hospital stay, morbidity, and mortality were analyzed.

RESULTS

A total of 159 patients underwent a reoperation after a laparoscopic colorectal surgery: 124 (78%) had RL and 35 (22%) LPM. Demographics were similar in both groups. Patients who underwent left colectomy were more frequently reoperated by laparoscopy (RL: 42.7% vs. LPM: 22.8%, p: 0.03). The most common finding at the reoperation was anastomotic leakage, which was treated more often by RL (RL: 67.7% vs. LPM: 25.7%, p: 0.0001), and the most common strategy was drainage and loop ileostomy (RL: 65.8% vs. LPM: 17.6%, p: 0.00001). Conversion was necessary in 12 patients (9.6%). Overall morbidity rate was 52.2%. Patients in the RL group had less postoperative severe complications (RL: 12.1% vs. LPM: 22.8, p: 0.01). Mortality rate was similar in both groups.

CONCLUSION

Relaparoscopy is feasible and safe for treating early postoperative complications, particularly anastomotic leakage after left colectomy.

National Surgical Quality Improvement Program analysis of unplanned reoperation in patients undergoing low anterior resection or abdominoperineal resection for rectal cancer

BACKGROUND

The rate of unplanned reoperation for rectal cancer can provide information about surgical quality. We sought to determine factors associated with unplanned reoperation after low anterior resection and abdominoperineal resection for patients with rectal cancer and outcomes after these reoperations.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was used to conduct this retrospective study. Patients who underwent elective low anterior resection and abdominoperineal resection for rectal cancer from 2012-2014 were identified. The primary outcomes were 30-day reoperation rates and postoperative complications.

RESULTS

A total of 454 low anterior resection patients (5.9%) and 289 abdominoperineal resection patients (8.1%) required reoperation within 30 days of their index operation. The most common reasons for reoperation were infection, bleeding, and bowel obstruction. Multivariate analysis revealed that male sex (odds ratio: 1.5, P = .001), poor functional status (odds ratio: 2.2, P = .04), operative time (odds ratio: 1.001, P = .01), low preoperative albumin (odds ratio: 0.79, P = .04), and lack of ostomy (odds ratio, 0.66, P = .005) were independent risk factors for reoperation after low anterior resection. Smoking (odds ratio: 1.7, P = .001), chronic obstructive pulmonary disease (odds ratio: 1.8, P = .03), poor functional status (odds ratio: 2.1, P = .032), operative time (odds ratio: 1.003, P < .001), low preoperative albumin (odds ratio: 0.69, P = .007), and open approach (odds ratio: 1.5, P = .02) were independent risk factors for reoperation after abdominoperineal resection. Postoperative complication rates are high for those undergoing reoperation, often leading to non-home discharge (P < .001) after reoperation.

CONCLUSION

Reoperation after low anterior resection and abdominoperineal resection for rectal cancer is not uncommon. This study highlights the indications for reoperation, potentially modifiable preoperative risk factors for reoperation, and the morbidity associated with such operations.