The main purpose of this study is to determine whether removing the gallbladder through different incision sites (ports) during laparoscopic surgery affects the risk of developing an incisional hernia. All patients undergo the same number of incisions, and the surgical technique remains standardized.

The study also aims to identify other factors that may contribute to the risk of hernia formation following gallbladder surgery.

Patients were blinded to group assignment. Randomization was conducted on the day of surgery by a surgical nurse using the Alea Randomisation mobile application (Alea Clinical Services, Abcoude, Netherlands). Group allocation ("U" for umbilical or "E" for epigastric) was placed in a sealed envelope and delivered to the operating room. The envelope was opened by the attending surgeon immediately prior to gallbladder retrieval.

Due to the nature of the intervention, the operating surgeon could not be blinded; however, surgeons remained unaware of group allocation until the moment of specimen retrieval. All procedures were performed by one of three experienced surgeons.

A conventional four-port laparoscopic cholecystectomy was performed in all cases, using a 10 mm umbilical camera trocar, a 10 mm epigastric trocar, and two 5 mm subcostal trocars. Gallbladder retrieval was performed using a laparoscopic specimen bag through one of the following approaches:

Group U: Gallbladder retrieved through the umbilical trocar

Group E: Gallbladder retrieved through the epigastric trocar

After retrieval and hemostasis, all trocars were removed under direct laparoscopic vision. The umbilical fascia was closed using two interrupted polyglactin 910 sutures (Vicryl, Ethicon Inc., Edinburgh, Scotland), while the epigastric trocar fascia was left unsutured. Fascia closure practices were standardized and unrelated to group allocation. Total operation time and gallbladder retrieval time were recorded.

All patients received paracetamol (Parol, Atabay İlaç, Istanbul, Türkiye) three times daily and tramadol (Contramal, Abdi İbrahim İlaç, Istanbul, Türkiye) twice daily for postoperative pain control. Pain was assessed using the Visual Analogue Scale (VAS) at 6 and 24 hours postoperatively, with the assistance of a ward nurse.

Patients without complications were discharged on postoperative day 1. Those with complications were discharged following resolution of their condition. All patients were followed for one year postoperatively. Patients presenting with hernia-related symptoms (e.g., bulge or pain) underwent ultrasonography (USG) at symptom onset, while asymptomatic patients received routine USG at the six-month and one-year follow-ups. Radiologists performing USGs were not affiliated with the study and were not standardized.

Incisional hernia was defined as a pathological fascial defect at a postoperative trocar site with protrusion of intraabdominal contents. Both clinically and radiologically diagnosed hernias were considered incisional hernias.

Inclusion Criteria:

• Age ≥ 18 years,
• Gallbladder stones
• No known systemic comorbidities (e.g., cardiovascular, pulmonary, metabolic, or immunologic conditions)

Exclusion Criteria:

• Age < 18 years,
• Open cholecystectomy or conversion from laparoscopy to open surgery,
• Acute cholecystitis
• Prior intervention involving the common bile duct,
• Presence of clinical or radiologic diastasis recti,
• Presence of clinical or radiologic umbilical hernia.

Raw data, consent forms, CSR, SAP

Unending (e.g., "Beginning 1 year after publication with no end date")

Statistical methods for those analyses must be approved by independent review. A proposal that describes planned analyses must be submitted