vNOTES, initially employed for cholecystectomy, appendectomy, and nephrectomy, made its debut in the field of gynecologic surgery in 2012. The advantages of vNOTES-such as minimized postoperative discomfort, quicker recovery, and superior cosmetic results-combined with gynecologists' familiarity with the vaginal approach, have contributed to the swift global adoption of vNOTES in gynecological procedures. Preliminary trials have demonstrated its safety and practicality.

Although laparoscopy plays a crucial role in surgical procedures, post-operative pain remains a major concern linked to this minimally invasive technique, despite being less intense than the pain from a laparotomy. Visceral pain after laparoscopy can stem from the stretching of the peritoneum and diaphragm caused by pneumoperitoneum, as well as from inflammatory cytokines released due to blood accumulation in the abdominal cavity. This pain is typically described as a dull, widespread ache found in the abdominal or thoracic region and often extends to the shoulders. It corresponds to a rise in painkiller use aligned with Enhanced Recovery After Surgery strategies for both preoperative and postoperative stages. Moreover, the Trendelenburg position could intensify shoulder pain due to increased diaphragm irritation from pneumoperitoneum.

Effective pain management promotes early movement, lowering the risk of blood clots and decreasing lung complications like atelectasis or pneumonia. Additionally, postoperative pain negatively impacts the quality of life immediately after surgery. To lessen both the occurrence and intensity of post-surgical pain, numerous experts advocate for the use of multimodal therapy in surgical patients.

The aim of this study was to evaluate the efficacy of combined low-pressure CO2 pneumoperitoneum and intraperitoneal infusion of normal saline for reducing the incidence and severity of postoperative pain.

Inclusion Criteria:

• Patients who received vNOTES hysterectomy and salpingectomy, with the option of additional procedures such as oophorectomy, uterosacral ligament plications, transobturator tape insertion, colporrhaphy, or sentinel lymphadenectomy.
• ASA status I-III
• Voluntary participation

Exclusion Criteria:

• Surgery time greater than 3 h,
• suspected infection or malignancy or rectovaginal endometriosis
• participation in other clinical trials.
• presence of pre-surgical shoulder pain or any acute or chronic pain syndromes
• cognitive impairment or communications disorder,
• previous use of opioids for chronic pain,