Transvaginal Natural Orifice Transluminal Endoscopic Surgery (vNOTES) Hysterectomy in Overweight and Obese Patients: Pearls and Pitfalls.

Transvaginal natural orifice transluminal endoscopic surgery (vNOTES) has become increasingly popular in the field of gynecological surgery.[ 1 ] This is a new surgical approach that uses the vagina as a natural orifice to perform laparoscopic surgery. It is commonly used to perform procedures such as hysterectomies, adnexectomies, and uterosacral ligament suspension.[ 2 3 ] Initial studies show vNOTES to be safe and feasible, with good operative outcomes and low rate of conversions.[ 4 5 ] This applies for patients with large uteri as well.[ 6 ] More recently, indications of vNOTES are expanding to include emergency gynecological surgery and oncological surgery for endometrial cancer.[ 7 8 ] This technique confers upon surgeons the dual advantages of vaginal and laparoscopic surgeries. For patients, the benefits of vNOTES are lesser postoperative pain, better cosmesis, and lower risk of injury through an abdominal incision.[ 9 ] For the surgeon, it allows for better visualization and manipulation of the adnexal structures. Studies have demonstrated these advantages and established the noninferiority of this vNOTES hysterectomy compared to conventional transabdominal or laparoscopic approaches.[ 10 11 12 ] Obese patients poses a complex challenge in gynaecological surgery, and the choice of surgical approach should be carefully discussed.[ 13 ] vNOTES has a theoretical benefit of less Trendelenburg as compared to traditional laparoscopic surgery, allowing for lower insufflation pressures and shorter operation time.[ 7 ] This reduces the risk of surgical morbidity and complications, which are associated with obesity during surgery.[ 14 15 ] Furthermore, overweight and obese patients are at higher risk of abnormal uterine bleeding (AUB), endometrial hyperplasia, and malignancy due to increased estrogen effect.[ 16 17 ] As such, they are more likely to have an indication for hysterectomy.[ 18 ] For these reasons, vNOTES appear to be an especially relevant minimally invasive approach for hysterectomy for the overweight and obese population. This is especially pertinent given the increasing incidence of obesity in the population, especially in Asia.[ 19 ] However, there remains a paucity of literature comparing this technique in obese compared to nonobese patients. To the best of our knowledge, there is such a study in a French population.[ 20 ] In our study, we aim to compare demographic, preoperative findings, intraoperative details, and postoperative outcomes between overweight, obese, and nonobese patients in an Asian population undergoing vNOTES hysterectomy.

The population characteristics are summarized in Table 1 . A total of 159 patients were included in this retrospective study, with 94 in the BMI <25 group and 65 in the BMI ≥25 group, respectively. The mean BMI is 22.3 ± 2.0 and 29.6 ± 3.7 for the two respective groups. Patients in the BMI ≥25 group had significantly higher parity and lower percentage of nulliparous women compared to the BMI <25 group (2.2 ± 1.1 vs. 1.7 ± 1.11 and 6.2% vs. 19.1%). However, there was no significant difference in other patient characteristics between the two groups, including age, preoperative Hb, history of previous vaginal birth, cesarean section, or abdominal surgery history. Characteristics of patients undergoing vaginal natural orifice transluminal endoscopic procedure BMI: Body mass index, Hb: Hemoglobin The adnexa procedures and additional procedures performed in addition to the vNOTES hysterectomy are summarized in Table 2 . There was no significant difference found in adnexa procedures and additional procedures performed between the BMI <25 and BMI ≥25 groups. The prolapse procedures performed included pelvic floor repair, sacrospinous ligament fixation, uterosacral ligament suspension, and McCall’s culdoplasty. Three patients with BMI 25 underwent Fenton’s procedure. Surgical procedures performed with vaginal natural orifice transluminal endoscopic surgery approach BMI: Body mass index The indications for surgery are summarized in Table 3 . It is important to note that some patients have more than one indication for the surgery. The most common indication for surgery was leiomyomas for both groups. Other than adenomyosis/endometriosis ± menorrhagia/AUB, the two groups had no significant differences in the indications for surgery. Indications for vaginal natural orifice transluminal endoscopic surgery hysterectomy AUB: Abnormal uterine bleeding, CIN: Cervical intraepithelial neoplasia, BMI: Body mass index The perioperative and postoperative outcomes are summarized in Table 4 . There were no conversions to open or laparoscopic surgery for any patient. Operative time was significantly longer in the BMI ≥25 group compared to the BMI <25 group (115.2 ± 46.8 min vs. 99.1 ± 37.8 min, P < 0.01). Length of stay was also longer in the BMI ≥25 group (1.75 ± 0.90 days vs. 1.46 ± 0.60 days, P < 0.01). There was significantly higher estimated blood loss in the BMI ≥25 group compared to the BMI < 25 group (189.2 ± 207.5 vs. 129.6 ± 146.5, P = 0.02). Perioperative and postoperative outcome of vaginal natural orifice transluminal endoscopic surgery in overweight patients a Based on 38 patients, 18 were in the BMI <25 group, and 20 of which were in the BMI ≥ 2. BMI: Body mass index, Hb: Hemoglobin Six patients required red blood cell transfusion postoperatively due to Hb drop, three in the BMI <25 group and BMI ≥25 group, respectively. All six patients had a uterus size of more than 12 weeks with either fibroid uterus or adenomyosis/endometriosis with adhesions. Six patients had postoperative fever, three in the BMI <25 group and three in the BMI ≥25 group. All patients recovered well after a course of antibiotics. There was one case of intraoperative complication in the BMI ≥25 group where the patient had superficial bowel serosa thermal burns not requiring any bowel resection. No patient had major organ injuries such as bladder or ureter injury. One patient in the BMI <25 group was admitted on postoperative day 7 for fever and infected pelvic hematoma. She was subsequently discharged after intravenous antibiotics and drainage of the pelvic hematoma by an interventional radiologist. Another patient was admitted for per vaginal bleed secondary to vaginal vault hematoma on postoperative day 7 and was managed conservatively. One patient in the BMI ≥25 group was also admitted on postoperative day 20 due to per vaginal bleed secondary to vaginal vault hematoma, which was managed conservatively. The perioperative and postoperative outcomes for obese patients (BMI ≥ 30) are summarized in Table 5 . Similarly, obese patients also had longer operative time (124.0 ± 56.1 min vs. 102.1 ± 38.3 min, P < 0.01) and longer postoperative stay compared to nonobese patients (1.81 ± 0.85 days vs. 1.53 ± 0.72 days, P = 0.04). However, there was no significant difference in estimated blood loss between both groups. Perioperative and postoperative outcome of vaginal natural orifice transluminal endoscopic surgery in obese patients b Based on 38 patients, 27 were in the BMI <30 group and 11 of which were in the BMI ≥30. BMI: Body mass index, Hb: Hemoglobin

vNOTES hysterectomy is a safe and feasible approach for overweight and obese patients. However, patients should be counseled on the risk of increased blood loss as well as longer operative time, and hospitalization stay. Further studies are needed to confirm our results. Conception and design of study: Kazila Bhutia, Ryo Chee, Ann Tan, Caleb Lim; Data acquisition, data analysis: Kazila Bhutia, Ryo Chee, Ann Tan; Manuscript preparation: Kazila Bhutia, Ryo Chee Ann Tan, Ng Qiu Ju, Qi Maili, Lee Jiah Min. All authors have read and agreed to the final version of the manuscript. The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request. There are no conflicts of interest.

Hysterectomy in an obese population may be more technically challenging due to increased intra-abdominal fatty tissue and poor tolerance of Trendelenburg position. Increased BMI of patients is also associated with higher risks of intraoperative blood loss, postoperative bleeding, and infection.[ 21 ] When there are no contraindications, the vaginal approach is preferred over laparoscopic or open abdominal approaches to perform hysterectomy in obese patients.[ 22 ] However, the literature and recommendations regarding vNOTES hysterectomy in obese patients remain limited. Table 6 summarizes the existing literature on vNOTES in obese patients compared to our study. Existing literature on vaginal natural orifice transluminal endoscopic surgery in obese patients *Did not report the exact number of intraoperative complications. BMI: Body mass index, vNOTES: Vaginal natural orifice transluminal endoscopic surgery There have been two other studies comparing vNOTES in obese and nonobese patients. Bouchez et al .[ 20 ] found that vNOTES hysterectomy is feasible to perform in obese patients, with no difference in rates of intraoperative conversions and perioperative and postoperative complications. Their study also found that obesity is associated with longer operative time and hospitalization stay when performing vNOTES hysterectomy, which is in keeping with the findings in our study. Another study by Bhalwal et al . showed no difference in median operative time, intraoperative, and postoperative complications when performing vNOTES hysterectomy and adnexal procedures in obese patients.[ 23 ] Regarding the longer operative time in the overweight and obese group, a potential reason could be the higher percentage of nulliparous patients in our study. While it may be feasible to perform, difficult vaginal access may render the surgery more technically challenging, hence increasing operative time.[ 28 ] Furthermore, the longer operative time in Bouchez et al .’s[ 20 ] study could be confounded by the larger number of concurrent procedures performed and greater percentage of hysterectomies performed by less experienced surgeons in the obese group compared to the nonobese group. Other hypothesized reasons include difficulty in installing vNOTES ports as well as deep vaginas and reduced vaginal and pelvic spaces limiting mobility of endoscopic instruments during surgery.[ 25 ] Four other studies have been published evaluating vNOTES hysterectomy in obese patients. Two studies by Mat et al . and Kaya et al . reported no conversions or major intraoperative complications when performing vNOTES hysterectomy in all patients.[ 24 25 ] Kaya et al . also reported that vNOTES hysterectomy had better outcomes compared to laparoscopic hysterectomy in obese patients, including shorter operative time, hospital stay, and lower pain score. Burnett et al . reported on vNOTES gynecological procedures in 103 morbidly and supermorbidly obese women for patients with BMI above 40 kg/m 2 and 50 kg/m 2 , respectively.[ 26 ] Their study had two conversions to laparoscopy, five conversions to laparotomy, and one postoperative complication of a vaginal cuff hematoma. Hurni et al . reported four conversions to laparoscopy when performing vNOTES hysterectomy and adnexectomy in 79 obese patients.[ 27 ] These studies show that vNOTES is feasible and safe even in obese patients. Overall, our study confirms the existing literature about the safety of performing vNOTES hysterectomy in an obese population, extrapolating these findings to an Asian population. Hence, vNOTES should be offered and discussed with obese patients. At the same time, they should be carefully counseled on the possibility of a higher risk of blood loss, longer operation, and hospitalization stay. There are certain limitations in our study. First, our study involved a small sample size. This study was conducted in a single tertiary center, and no sample size was calculated before the study. Larger multi-center trials should be performed in the future to validate the safety and efficacy of vNOTES hysterectomy in the obese population. Second, this was a noncomparative study. Future studies should focus on the comparison of surgical outcomes between vNOTES and other surgical approaches when performing hysterectomies for overweight and obese patients.

A retrospective study was conducted between April 15, 2021, and January 24, 2024, at KK Women’s and Children’s Hospital (KKH), Singapore’s largest gynecological tertiary care center. The vNOTES procedure was first introduced in KKH in 2021. All patients who underwent vNOTES hysterectomy during this period were included in our study. Before surgery, all patients underwent detailed history, abdominal and pelvic examination, and pelvic imaging (usually a pelvic ultrasound). All vNOTES hysterectomies were performed by three experienced gynecological surgeons in our center. According to institutional guidelines, all patients underwent a follow-up visit approximately 2 weeks and 2 months after the surgery. The patient demographic data collected were: age, body mass index (BMI), preoperative hemoglobin level (Hb), parity, history of vaginal delivery, previous cesarean section, previous abdominal surgery, and indication for surgery. The operative data collected were: procedure performed, total operative time, uterine weight, estimated blood loss, intraoperative and postoperative complications, intraoperative conversion, maximum pain score, length of hospitalization stay, and postoperative Hb. Patients were divided into two groups based on their BMI: nonoverweight (<25 kg/m 2 ) or overweight (≥25 kg/m 2 ). Total operative time was defined as time from incision to closure. Intraoperative conversion was defined as any need to perform an open or laparoscopic surgery. Intraoperative complication was defined as any event that affects the patient during surgery. Postoperative complication was defined as any complication after the surgical intervention to the follow-up visit. The length of stay was defined as the time between admission for surgery and discharge. The pain score was recorded using the numeric rating scale. All surgeries were performed under general anesthesia with the patient in the dorsal lithotomy position with a slight Trendelenburg. Patients received intravenous antibiotic prophylaxis preoperatively. The surgical field was cleaned and draped. The bladder was emptied using an in-and-out Foley catheter. Diluted 0.5% bupivacaine in 1:200,000 adrenaline was used to infiltrate around the cervix. A circumferential incision was made around the cervix, and vaginal mucosa was mobilized to expose the uterosacral and cardinal ligament. The bilateral uterosacral and cardinal ligament complexes were clamped, cut, and transfixed to create enough lateral space to allow the sleeve of the vNOTE device to be fitted optimally. The colpotomy incision was made to enter the Pouch of Douglas, followed by an anterior incision to enter the anterior pelvic cavity. An Alexis ® O-Retractor (Applied Medical Resources Corp., Rancho Santa Margarita, US) was then introduced into the anterior vesicovaginal space anterior to the cervix and lower uterine wall, and the other end was introduced in the Pouch of Douglas. GelPOINT V-Path transvaginal access platform or handmade gloved port was attached to the rim of the Alexis® O-Retractor. Three or four trocars were fitted into the GelPOINT or gloved port. The pneumoperitoneum was then created with carbon dioxide (8–10 mmHg). A 10 mm 30° or 0° rigid laparoscope, conventional laparoscopic instruments, and an energy device were used. Following the surgery, specimens were retrieved through the vagina, and the vaginal vault was closed using dissolvable sutures. Routine mechanical deep vein thrombosis prophylaxis was given to our patients, i.e., compression stockings, calf compressions, and ambulation immediately postoperatively. Low-molecular-weight heparin at 1 mg/kg was also given if there were no contraindications, for example, excessive bleeding during the surgery or low platelets. This research was performed in accordance with the Helsinki Declaration of 1975. This study was exempted by the institutional IRB review as the study was approved under clinical improvement project in KK Research Centre of KK Women’s and Children’s Hospital. This study was classified as a clinical audit study and did not require patients’ consent based on our local ethics institutional review board. All statistics were performed using R software (version 4.2.3) (RStudio Team (2023), RStudio: Integrated Development for R. RStudio, PBC, Boston). Quantitative data are displayed as mean (±standard deviation) in the case of normal distribution unless otherwise stated. The normality of distribution was confirmed using the Shapiro–Wilk test. Qualitative data are displayed as numbers and percentages. Comparisons between both groups were performed using the Student’s t -test and Fisher’s exact test for quantitative and qualitative data, respectively. The statistical threshold is set at 0.05.