The cesarean section (CS) is the most commonly performed surgery on women [1]. Increasing CS rates inevitably cause long-term obstetric and gynecological complications. An isthmocele is defined as an indentation at the site of a CS scar with a depth of at least 2 mm [2]. Synonyms frequently used in the literature to describe this defect include uterine scar defect, niche, cesarean scar defect, uterine diverticulum, pouch, or sacculation [3], [4], [5]. The prevalence of isthmocele was reported to be between 24% and 70% if evaluated via ultrasonographic examination and could reach 56% and 84% with saline infusion sonography following ≥1 CS [5], [6], [7], [8].

Poor healing of the uterine incision leads to isthmocele formation. Long-term morbidities associated with isthmoceles include cesarean scar pregnancy, uterine rupture, pelvic pain, and menstrual irregularity [3,8,9]. Many surgical and patient-related factors that may affect the healing of uterine scars have been reported in the literature (i.e., double- or single-layer closure, locked or unlocked closure, and uterine retroflection) [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20]. Although evidence-based literature emphasizes the significance of surgical technique in wound healing, the debate persists regarding which technique provides the best healing outcomes [10].

Suturing a complete fold of the wound lips during uterine closure may result in the endometrial layer being embedded in the myometrium, potentially leading to niche tissue formation. Passing the needle through the myometrial-endometrial junction and using a suturing technique that avoids involvement of the endometrium can facilitate better alignment of uterine compartments and enhance better wound healing (Figure 1). This study hypothesized that isthmocele development could be reduced by suturing without enclosing the endometrium during uterine closure.