Enlarged uterus is frequently encountered in clinical practice, and its incidence due to conditions such as adenomyosis, uterine fibroids, and other gynecological disorders has steadily increased over the years statistically. For example, greater healthcare awareness has led to more frequent early diagnoses of these conditions, contributing to the observed rise in incidence. Additionally, increasing life expectancy results in more women reaching the perimenopausal and postmenopausal stages, during which conditions like uterine fibroids and adenomyosis become more prevalent. For these women, hysterectomy (removal of the entire uterus) is often the recommended option of treatment.

With advances in surgical techniques over recent decades, there has been a notable shift from traditional open abdominal surgeries to minimally invasive approaches. Laparoscopic surgery has been widely adopted, significantly reducing the size and number of incisions required, thereby promoting faster recovery, minimizing postoperative pain, and reducing the risk of complications.

However, conventional multi-port laparoscopic hysterectomy still presents certain challenges, such as large uterus extraction following resection, and concerns about healing of incisions. In contrast, innovative techniques like Transumbilical Laparoendoscopic Single-Site Surgery(TU-LESS) and Transvaginal Natural Orifice Transluminal Endoscopic Surgery(vNOTES) both take advantage of natural anatomical openings to achieve minimal or no visible scarring. Studies demonstrate that these techniques provide superior outcomes in terms of reduced pain, faster recovery, and quicker return to daily activities compared to traditional multi-port laparoscopic approaches.

Yet a direct comparison of the efficacy of these two methods in real-world, particularly for enlarged uterus, remains inconclusive. Thus this study aims to evaluate and compare the outcomes of these two techniques in patients with enlarged uteri. Participants will be randomly assigned to receive one of the two surgical approaches, ensuring an unbiased comparison of the efficacy of the procedures in terms of healing status and recovery time.

Enlarged uterus, mainly caused by adenomyosis, is often associated with symptoms like compression of intestines and urethra(presenting as constipation, urinary frequency, and urgency), dysmenorrhea, menstrual irregularity, and anemia due to menorrhagia. A hysterectomy (removal of the uterus) is often recommended, especially in cases where conservative management like medical treatment fails.

Among all the methods of hysterectomy, TU-LESS and vNOTES are noted for minimized invasiveness and fast recovery. As vNOTES is performed through the vagina and TU-LESS involves a single incision through the umbilicus, they both utilize natural anatomical openings, resulting in minimal to no visible scarring.

Inclusion Criteria:

• Eligible women aged 18-70 years.
• Women with indications for enlarged uterine volumes who are planning to under go total hysterectomy. Uterine size should exceed that of a 3-month pregnancy (uterine weight ≥ 280 g).
• Patients are willing to be randomly assigned to undergo any of both approaches.
• Patients who are willing to sign the informed consent form.

Exclusion Criteria:

• Individuals who are virgins or have vaginal stenosis.
• Patients requiring concurrent surgical intervention for conditions such as ovarian cysts or lesions of the vulva, vagina, appendix, etc.
• presence of uterus exceeding approximately 20 gestational weeks in size (about 900-1000g), which is beyond the limitations of a single-site laparoscopic approach due to concerns regarding technical feasibility and safety
• Presence of malignancy or strong suspicion of malignancy that may alter the planned surgical approach.
• History of two or more pelvic surgeries or suspected severe pelvic adhesions (rectovaginal examination suggesting rectovaginal endometriosis or limited uterine mobility).
• History of peritoneal dialysis, pelvic radiation therapy and pelvic tuberculosis treated with laparoscopic surgery.
• Patients with prolapse or pelvic inflammation.
• Diabetes mellitus with poor blood glucose control.
• Body mass index greater than 30 kg/m².

Enlarged uterine volumes occur only to female population

Patients will remain blinded to their surgical methods in 24 hours following the operation. To achieve this, we will apply wound pads to each patient's abdomen as the wounds typically seen in tradi tional laparoscopy procedures, no matter whether actual wounds exist.