Comparison of different uterine incision closure methods used in cesarean section in terms of postoperative cesarean incision scar thickness and istmosel formation

Caesarean section, also known as C-section, or caesarean delivery, is the use of surgery to deliver babies. A caesarean section is often necessary when a vaginal delivery would put the baby or mother at risk. World Health Organization advocates that the ideal caesarean section rate should be below % 10-15 in all societies. Due to the high rates of cesarean delivery, long-term adverse consequences are becoming increasingly important. Caesarean scar defect size is thought to play a role in the risk of uterine rupture in subsequent pregnancies. Although the factors involved in cesarean scar formation cannot be clearly clarified; changes in maternal age, uterine position, labor induction, uterine incision closure are blamed. It has been shown that there may be differences between single layer - double layer, locked - unlocked techniques in terms of cesarean scar morphology. In this study, we aimed to evaluate the effect of four different uterine incision closure techniques (single layer - double layer and locked - unlocked) in cesarean scar healing and isthmosel formation by postpartum TVU and SİS in pregnants delivered by elective first cesarean section. MATERIAL AND METHOD: Our study is a prospective randomized controlled study including elective, term, first cesarean section at Dokuz Eylul University Hospital, Department of Obstetrics and Gynecology between November 2018 and November 2019. Patients with their first cesarean section between the ages of 18-40, who agreed to come to the control at 6 weeks postpartum, and patients whose prenatal information and follow-up was found in the file were included. Under 37 weeks of gestation, with labor (having active contractions with cervical patency of 4-5 cm or more), those with placenta previa, those with previous uterine surgery, with a diagnosis of immune system disorder (such as insulin-dependent diabetes mellitus) who did not accept follow-up, were not included in the study. Patients were evaluated by SIS and TVUSG at the 6th week. 67 patients were randomized using simple random numbers table for randomization. A total of 44 patients (11 patients per group) from all 4 groups were evaluated. The first group was applied with single layer locked, the second group with single layer unlocked, the third group with double layer locked, and the fourth group with double layer unlocked. Using the SIS method; the width, depth and length of the scar tissue and the thickness of the residual myometrium tissue were measured. Three-dimensional Voluson E8 TVUSG was used. The degree of the niche was determined by calculating the height and base width of the scar tissue and the existing niche area. Less than 15 mm² were recorded as grade 1, between 16-25 mm² were classified as grade 2, and larger than 25 mm² were recorded as grade 3. All measurements; performed by the same ultrasound device and the same surgeon, unaware of which technique was applied. RESULTS: Total of 44 patients, including 11 from each group, were included in the study. There was no difference between the ages of the single and double layer groups (28,90 - 31,05) (p>0,05). Body mass indexes between two groups were similar (28.40 - 27.50) (p> 0.05). Between the two groups there was no statistically significant difference about mean measurements of cesarean scar depth (4.42 mm-4.02 mm), width (5.59 mm-4.74 mm), length (8.58 mm-8.67 mm) and residual myometrium thickness (7,54 mm-7.93 mm) (p>0,05). Grade 1 isthmosel was found in 47% of 44 patients, grade 2 in 30% and grade 3 in 23%. When two techniques were compared, grade 3 isthmocele were observed in single layer technique more than double layer (%32-%14). But, it was not statistically significant (p>0,05). When the postoperative symptoms were questioned, it was observed that only pelvic pain was present and the rate of this symptom was similar between the groups. There was no difference between groups in terms of cesarean operation time, additional suture and blood requirement (p>0,05). CONCLUSION: Studies on the most appropriate uterine closure technique are still ongoing. The size of cesarean scar defect depends on multifactorial causes. Postoperative control time changes in studies because there is no complete opinion about the duration of wound healing. In this study, we compared the postoperative results using four different uterine closure techniques with the help of saline infusion sonography. We did not observe a significant difference in terms of measurements and istmosel sizes. This type of prospective studies with more patient and long-term follow-up will contribute to the literature. Keywords: cesarean birth; uterus closure technique; isthmocele; saline infusion sonography