Abdominal Wall Dehiscence After Laparotomy Closure in Abdominal Surgery: a Retrospective Observational Study on the Influence of the Suture Used

In this retrospective longitudinal observational study we primarily aim to compare the influence of the applied suture type (Stratafix Symmetric versus other suture types) for primary fascial closure in abdominal surgery on the incidence of fascial dehiscence.

Secondary outcomes such as will also be analized. Primary outcomeis the incidence of abdominal wall dehiscence. Secondary outcomes are the impact of the occurrence of abdominal wall dehiscence on mortality and hospital stay, the influence of other risk factors on the occurrence of abdominal wall dehiscence, the influence of the suture type and other risk factors on the incidence of incisional hernia after 12 months of follow-up and a speciality subgroup analysis.

The diagnoses of each patient and the procedures performed are coded according to ICD 9 or ICD 10. For primary cause diagnoses and secondary diagnoses, external causes and procedures, ICD9/ICD10 codes are also used. Following the AHQR definition, cases of laparotomy dehiscence will be defined as those whose ICD 9/ICD 10 codes conform to "New closure of postoperative abdominal wall disruption", as well as those identified secondarily after crossing the databases as reoperated for this reason with another coding.

Statistical analysis will be performed using statistical techniques appropriate to the variables under study. A descriptive analysis of the population will be performed, frequency results will be expressed in absolute terms, such as percentages and confidence intervals. The percentage of subjects with dehiscence will be calculated by the group. A two-sided 95% confidence interval (CI) for the difference in percentages (Stratafix - Control) will be estimated using the Wald method. If the upper limit of the confidence interval for the difference in percentages (Stratafix-Control) is below 0, then it will be concluded that the true dehiscence rate for Stratafix is lower than that for the control. In addition, two-sided 95% CIs within each group will be estimated for the dehiscence rate using the Clopper-Pearson method.

Continuous variables will be expressed as mean (SD) and median (range) according to the normality test (Kolmogorov Smirnov test). For the study of the relationship between the different variables, Chi-square or Analysis of Variance will be used if they are parametric. And if they do not follow a normal distribution, nonparametric tests will be used (Mann-Whitney U or Kruskal Wallis, as appropriate). Biochemical recurrence-free survival (BCR-free survival) will be estimated using Kaplan-Meier curves. SPSS. 21 (SPSS Inc. Chicago, IL, USA) will be used.