[Short-term results in colorectal surgery. Statistical analysis about mortality, morbidity and hospital stay]

The surgical approach on the colon and rectum represents a wide slice of the surgical procedures carry out in election or emergency in a general surgery unit. The literature reports prospective and retrospective studies evidencing emergency surgery, advanced age, comorbidity and other factors can determinate a worsening of short-term outcome (postoperative mortality, morbidity and hospital stay). The aim of the study was to verify, through a statistical analysis on a group of patients operated on the colon and the rectum, which are the factors weighting on the short-term outcome.

Our retrospective study is carried out on 150 patients consecutively operated on the colon and rectum from January 2002 to September 2004 in elective or emergency surgery in the Unity of General Surgery of the Hospital S. Maria Nuova Azienda Sanitaria of Florence. The variables for the statistical analysis were: sex, age, comorbidity, nature of pathology, timing of surgery, type of emergency, lesion location, surgical intervention, presence of social factors delaying the discharge, blood transfusion, Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity (POSSUM-score).

The mortality study found the advanced age (>70 years) as risk factor in the univariate analysis, not confirmed in the multivariate one. The morbidity study found advanced age, presence of comorbidity and blood transfusion as risk factors in the univariate analysis, not confirmed in the multivariate one. The POSSUM-score represents in both multivariate analyses the only statistically meaningful parameter correlated with mortality (P<0.005) and morbidity (P<0.05). The multivariate analysis in the study on the hospital stay found that more staged surgery carry to a lengthening of hospital stay (P<0.0001); in minor such measure blood transfusion (P=0.0005), emergency surgery (P=0.002) and presence of social factors (P=0.008); comorbidity (P=0.02) and advanced age (P=0.03) had less statistical weight.

Despite of the literature, this study found none of the analyzed variables related on postoperative mortality and morbidity in statistically meaningful way. The POSSUM-score demonstrated once again validity in estimating the probability of dead and of postoperative complications. The variables that influenced in lengthening of hospital stay were: more staged surgery, blood transfusion, emergency surgery, presence of social factors conditioning the discharge, comorbidity and advanced age of the patients. The good results about mortality and morbidity can be explained by the fact we prefer in emergency more staged surgery that protect the patients from complications related to the anastomosis, the presence of sub-intensive surgical beds with a constant monitoring of high risk patients and the close collaboration between surgeons and intensive care medical doctors.