Prospective evaluation of in-hospital mortality with the P-POSSUM scoring system in patients undergoing major digestive surgery.

BACKGROUND: The P-POSSUM score, the most well known of predictive scores for postoperative mortality, requires validation for population and setting. METHODS: Validation methods included discrimination (C-index statistic), observed:expected (O:E) ratio, calibration with the Hosmer-Lemeshow test, and subgroup analysis (emergency surgery, cancer, age, organs). The study included 3,881 multisite patients undergoing major digestive surgery in France. RESULTS: Discrimination via the receiver operating characteristic curve was good (C-index = 0.87). The overall O:E ratio was 1 (95% confidence interval ([95 % CI]: 0.88-1.13), and therefore the quality of the surgical performance is within normal ranges. The O:E ratio, calculated by risk ranges, showed overestimation in the low risk range, especially in the 3 % to 6 % and 6 % to 10 % ranges. Calibration was poor (p < 0.001). The model deviated from the normal pattern of calibration, with mortality lower than expected in the high-risk range. Subgroup analysis found reasonable to good discrimination of populations (C-index ranging from 0.78 to 0.93 except for liver surgery [0.67]) while calibration of individuals remained poor (p < 0.001 to 0.02). CONCLUSIONS: Good discrimination, as well as nonsignificant overall O:E values, makes P-POSSUM a valuable tool when it is used for surgical audit to compare mortality between populations for major digestive surgery. Conversely, poor calibration (goodness-of-fit), especially in subgroup analysis, and underestimation or overestimation of O:E ratios considerably limits the value of P-POSSUM for prediction of mortality in individuals. Therefore P-POSSUM should not be used to predict outcomes for one particular patient.

Safety and long-term outcome of a new concept for surgical adhesion-reduction strategies (Prevadh): a prospective, multicenter study.

BACKGROUND/AIMS: No agent has been consistently effective in preventing formation of peritoneal adhesions and postoperative bowel obstruction after abdominal surgery. The aim of this prospective multicenter study was to assess clinical safety and efficiency of a new adhesion-reduction barrier METHODOLOGY: Between September 2000 and April 2001, Prevadh was used in 78 patients. Operative procedures included 25 hepatic resections, 7 cholecystectomies, 32 colonic resections, 7 protectomies, 3 colostomy or recovery of continuity, 1 gynaecologic surgery and 3 others. Eleven patients were operated on by laparoscopy and 67 by laparotomy. RESULTS: The overall incidence of abscesses and wound complications was 2.4% and 9% respectively. After a mean follow-up of 36 months (range: 4-51 months), no patients experienced adverse events related to the adhesion barrier. Surgical reoperative procedures were performed in 10 patients for unrelated causes and no bowel obstruction occurred within the protected area. CONCLUSIONS: This study confirmed the safety of Prevadh adhesion barrier and suggested that this resorbable barrier might provide prevention from adhesion formation on peritoneal injured surfaces. However, a large randomized controlled trial remains necessary to prove the real effectiveness of adhesion barriers on clinical long-term outcome.