Objectives and hypothesis of the study The primary objective: to identify the best suture
size for closure of the fascia following laparotomy incisions to prevent incisional hernia,
by assessing the suture size 2\0 versus zero.
Secondary objective: assess the incidence of wound dehiscence and wound infection in two
studied group.
Study hypothesis: Suture size 2/0 decreases the incidence of incisional hernia in the closure
of the abdominal fascia
Research design and Methods Study design: Prospective, multicentric, randomized controlled
and double-blind trial.
Characteristics of study area and target population Patients undergoing elective or emergency
laparotomy in Royal Hospital, Sultan Qaboos University Hospital and Armed Force Hospital
between 2022 and 2023. Eligible patients are adults aged 18 years or older, who signed
informed consent and the expected survival more than one year. Patients with history of
midline laparotomy within 3 months, pregnant patients and patients with history of incisional
hernia will be excluded from the study.
Sampling we estimated that 125 patients would be needed in each group to provide 80% power to
detect a reduction of at least 50% (18% in the classic group vs 6% in the 2.0 group) in the
incidence of incisional hernia at a two-sided alpha level 0.05. We aimed for a total of 276
patients (n=138 per group) to correct for an estimated 10% loss to follow-up in each group.
The statistical method used was Fisher's exact test. The calculation was done using the
software G*Power version 3.1.9.2. Randomization will be achieved by using a software.
Variable definitions and measurements The abdomen will be closed in the intervention group
patients with continuous PDS 2\0 sutures, half centimeter between each stitch. The control
group will be closed by the conventional method in the Royal Hospital, continuous using
double-looped. Sex, age, BMI, smoking, diabetes mellitus, COPD, cardiovascular disease,
corticosteroid use, previous laparotomy, ASA classification, preoperative chemotherapy,
preoperative radiotherapy, type of surgery are the variable which will be studied.
Data collection tools and methods Data will be entered using Epi-data software.
Data quality State how data will be entered using Epi-data software.
Data analysis Continuous variables will be presented as mean, median, and standard deviation
whereas, categorical variables will be presented as frequency and percentage. Comparison of
means between two groups will be assessed using the independent samples t-test or the
Mann-Whitney U test, as appropriate. Association between two categorical variables will be
assessed using an appropriate Chi-square test (Likelihood ratio test or Fisher's exact test).
Multivariate log-binomial regression analysis will be used to determine the independent risk
factors for the development of incisional hernia. A P-value less than 0.05 will be considered
statistically significant. All the analysis will be done using the IBM SPSS statistics
version 26.0.