Interhospital variability of risk-adjusted mortality rates and associated structural factors in patients undergoing emergency laparotomy: England and Wales population-level analysis.

BACKGROUND: Emergency surgical admissions represent the majority of general surgical workload. Interhospital variations in outcomes are well recognized. This analysis of a national laparotomy data set compared the best- and worst-performing hospitals according to 30-day mortality and examined differences in process and structural factors. METHODS: A retrospective multicenter cohort study was performed using data from the England and Wales National Emergency Laparotomy Audit (December 2013 to November 2020). The data set was divided into quintiles based on the risk-adjusted mortality calculated using the National Emergency Laparotomy Audit score risk prediction model. Primary outcome was 30-day mortality. Hospital-level factors were compared across all five quintiles, and logistic regression analysis was conducted comparing the lowest with the highest risk-adjusted mortality quintiles. RESULTS: Risk-adjusted 30-day mortality in the poorest performing quintile was significantly higher than that of the best performing (11.4% vs. 6.6%) despite equivalent predicted mortality (9.4% vs. 9.7%). The best-performing quintile was more likely to be a tertiary surgical (49.5% vs. 37.1%, p < 0.001) or medical school-affiliated center (26.4% vs. 18.0%, p < 0.001). In logistic regression analysis, the strongest associations were for surgery performed in a tertiary center (odds ratio, 0.690 [95% confidence interval, 0.652-0.731], p < 0.001) and if surgery was performed by a gastrointestinal specialist (0.655 [0.626-0.685], p < 0.001). Smaller differences were seen for postoperative intensive care stay (0.848 [0.808-0.890], p < 0.001) and consultant anesthetist involvement (0.900 [0.837-0.967], p = 0.004). DISCUSSION: This study has identified significant variability in postoperative mortality across hospitals. Structural factors such as gastrointestinal specialist delivered emergency laparotomy and tertiary surgical center status appear to be associated with improved outcomes. LEVEL OF EVIDENCE: Original Research Article; Level II.

Trends in emergency colorectal surgery: a 7-year retrospective single-centre cohort study.

BACKGROUND: Emergency colorectal resections carry a higher morbidity and mortality than elective surgery. The use of minimally invasive surgery has now become widespread in elective colorectal surgery, with improved patient outcomes. Laparoscopy is being increasingly used for emergency colorectal resections, but its role is still being defined. Our aim was to observe the uptake of laparoscopy for emergency colorectal surgery in our centre. METHOD: A retrospective single-centre cohort study was performed using local National Emergency Laparotomy Audit data from January 2014-December 2020. All patients who had a colorectal resection were included. Trends in the number and type of resections were recorded. Primary outcome was the proportion of cases started and completed laparoscopically. Secondary outcomes included rate of conversion to open, length of stay and 30-day mortality. RESULTS: A total 523 colorectal resections were performed. The number of cases attempted and completed laparoscopically steadily increased over the study period (28.3% to 63.3% and 16.3% to 35.4%, respectively). The mean rate of conversion to open was 43.8%. The greatest expansion in laparoscopy was for cases of intestinal obstruction, perforation and peritonitis, and for those undergoing Hartmann's procedure and right hemicolectomy. 30­day mortality for cases completed laparoscopically was much lower than those converted or started with open surgery (2.1% vs 11.7% and 17.5%, respectively). Laparoscopic approach was independently associated with reduced length of stay. CONCLUSION: Laparoscopy has been successfully adopted for emergency colorectal resections in our centre, with half of cases felt to be suitable for minimally invasive surgery.

P-POSSUM and the NELA Score Overpredict Mortality for Laparoscopic Emergency Bowel Surgery: An Analysis of the NELA Database.

BACKGROUND: Risk stratification has become a key part of the care processes for patients having emergency bowel surgery. This study aimed to determine if operative approach influences risk-model performance, and risk-adjusted mortality rates in the United Kingdom. METHODS: A prospectively planned analysis was conducted using National Emergency Laparotomy Audit (NELA) data from December 2013 to November 2018. The risk-models investigated were P-POSSUM and the NELA Score, with model performance assessed in terms of discrimination and calibration. Risk-adjusted mortality was assessed using Standardised Mortality Ratios (SMR). Analysis was performed for the total cohort, and cases performed open, laparoscopically and converted to open. Sub-analysis was performed for cases with ≤ 20% predicted mortality. RESULTS: Data were available for 116 396 patients with P-POSSUM predicted mortality, and 46 935 patients with the NELA score. Both models displayed excellent discrimination with little variation between operative approaches (c-statistic: P-POSSUM 0.801-0.836; NELA Score 0.811-0.862). The NELA score was well calibrated across all deciles of risk, but P-POSSUM over-predicted risk beyond 20% mortality. Calibration plots for operative approach demonstrated that both models increasingly over-predicted mortality for laparoscopy, relative to open and converted to open surgery. SMRs calculated using both models consistently demonstrated that risk-adjusted mortality with laparoscopy was a third lower than open surgery. CONCLUSION: Risk-adjusted mortality for emergency bowel surgery is lower for laparoscopy than open surgery, with P-POSSUM and NELA score both over-predicting mortality for laparoscopy. Operative approach should be considered in the development of future risk-models that rely on operative data.