Comparison of different types of single-port laparoscopic surgery in posterior uterine fibroid resection.

The study enrolled 79 patients, comprising 32 in the LESS group and 47 in the vNOTES group (subdivided into subgroups based on positioning, including 17 in the lithotomy position and 30 in the prone position). General patient information is presented in Table 1 , while Table 2 displays the results of basic data analysis. There were no statistically significant differences among the three groups in terms of age, BMI, medical history, surgical history, and parity. The mean maximum diameter of myomas was 6.57 ± 1.49 in the LESS group, 6.42 ± 1.56 in the vNOTES-P subgroup, and 6.22 ± 1.76 in the vNOTES-L subgroup, with no statistically significant differences observed among the three groups. Table 1 Description of the patients demographic characteristics and operation types. Variables Total Patients 79 Age (year) 37.49 ± 8.21 BMI (kg/m 2 ) 22.33 ± 2.66 Max diameter of myoma (cm) 6.44 ± 1.56 Dysmenorrhea 23(29.1%) Diabetes 2(2.5%) Hypertension 3(3.8%) History of pelvic surgery 32(40.5%) Previous delivery mode Cesarean section 27(34.2%) Vaginal delivery 36(45.6%) Un-delivery 16(20.2%) Myomectomy type Laparoendoscopic single-site surgery (LESS) 32(40.5%) V-NOTES 47(59.5%) Prone position 30(63.8%) Bladder lithotomy position 17(36.2%) Table 2 Description of the patient characteristics by myomectomy types. Variables LESS v-NOTES P-value Prone position Lithotomy position Patients N = 32 N = 30 N = 17 Age (year) 36.91 ± 8.39 36.63 ± 7.81 40.12 ± 8.52 0.332 a BMI (kg/m 2 ) 22.25 ± 2.63 22.26 ± 2.80 22.61 ± 2.59 0.892 a Dysmenorrhea 9(28.1%) 11(36.7%) 3(17.6%) 0.381 b History of pelvic surgery 12(37.5%) 12(40.0%) 8(47.1%) 0.808 b Max diameter of myoma (cm) 6.57 ± 1.49 6.42 ± 1.56 6.22 ± 1.76 0.758 a Gestation status Cesarean section 10(31.3%) 11(36.7%) 6(35.3%) 0.899 b Vaginal delivery 16(50.0%) 10(33.3%) 10(58.8%) 0.195 b Un-delivery 6(18.7%) 9(30.0%) 1(5.9%) 0.109 c Operative information Procedure time (min) 114.44 ± 40.56 101.4 ± 38.17 123 ± 47.95 0.202 a Bleeding volume (mL) 67.81 ± 61.37 67.67 ± 104.11 64.71 ± 66.72 0.991 a Surgical conversion 0(0%) 0(0%) 2(11.8%) 0.026 c Surgical injury 0(0%) 0(0%) 1(5.9%) 0.120 c Post-operative information Hemoglobin decline (g/L) 20.91 ± 14.1 21.3 ± 14.21 19.18 ± 9.44 0.964 a Hospital stay (day) 4.22 ± 1.14 4.04 ± 1.05 4.09 ± 1.11 0.197 d Exhaust time (hour) 37.56 ± 14.4 28.23 ± 9.13 29.65 ± 15.32 0.011 d Infection 0(0%) 2(6.7%) 1(5.9%) 0.232 c Re-surgery 0(0%) 1(3.3%) 0(0%) 0.806 c a Average and standard deviation. One-way analysis of variance. b Number (percentage). Chi-squared test. c Number (percentage). Fisher exact test. d Average and standard deviation. Kruskal–Wallis test. Description of the patients demographic characteristics and operation types. Description of the patient characteristics by myomectomy types. a Average and standard deviation. One-way analysis of variance. b Number (percentage). Chi-squared test. c Number (percentage). Fisher exact test. d Average and standard deviation. Kruskal–Wallis test. As shown in Table 2 , the surgical duration for the LESS group, vNOTES-P, and vNOTES-L were 114.44 ± 40.56 min, 101.4 ± 38.17 min, and 123 ± 47.95 min, respectively, with no statistically significant differences observed among the groups. Intraoperative blood loss was 67.81 ± 61.37 ml for the LESS group, 67.67 ± 104.11 ml for the vNOTES-P subgroup, and 64.71 ± 66.72 ml for the vNOTES-L subgroup, with no statistically significant differences among the three groups. Two patients in the vNOTES-L subgroup underwent intraoperative conversion to a different surgical approach, while all surgeries were completed as planned in the other two groups, with statistically significant differences observed among the three groups. One intraoperative injury occurred among the 79 patients, which was observed in the vNOTES-L subgroup. The decrease in hemoglobin levels was 20.91 ± 14.1 ml in the LESS group, 21.3 ± 14.21 ml in the vNOTES-P group, and 19.18 ± 9.44 ml in the vNOTES-L group, with no statistically significant differences observed. The postoperative length of hospital stay was approximately 4 days for all groups, with no significant differences noted. Regarding postoperative flatus time, the LESS group had a mean duration of 37.56 ± 14.4 h, while the vNOTES groups had durations of 28.23 ± 9.13 h for vNOTES-P and 29.65 ± 15.32 h for vNOTES-L, demonstrating a significant difference (P = 0.01). However, there were three cases of postoperative infection in the vNOTES group, whereas there were none in the LESS group. Notably, one patient in the vNOTES-P subgroup required a second surgery postoperatively. Table 3 presents the analysis results regarding the differences in surgical time. Age, body mass index (BMI), and history of previous pelvic surgery did not influence the duration of the surgical procedure. Similarly, whether using single-port laparoscopy via the umbilicus or transvaginal single-port access did not affect the surgical time. However, in vNOTES procedures, the operating time was significantly reduced in the prone position group compared to the lithotomy position group, with a statistically significant difference (P < 0.05). Presence of adhesions or intraoperative changes in surgical approach increased the duration of surgery, with a statistically significant difference. Lastly, for each 1 cm increase in tumor diameter, the surgical time extended by 7.4 min, with a statistically significant difference observed (P = 0.01). Table 3 Association between procedure time and perioperative characteristics. Variables Beta 95% CI P-value VIF R 2  = 0.256 Age (year)  − 0.428 (− 1.523, 0.667) 0.438 1.086 Tumor size (cm) 7.435 (1.794, 13.077) 0.011 1.045 BMI (g/m 2 )  − 0.615 (− 3.991, 2.761) 0.717 1.079 History of pelvic surgery  − 4.266 (− 22.408, 13.876) 0.641 1.078 Prone-/lithotomy-position 13.159 (5.505, 20.812) 0.027 1.847 Abdominal-/vaginal-approach 3.282 (− 9.184, 15.747) 0.601 1.936 Pelvic adhesions 14.900 (4.211, 25.589) 0.015 1.102 Surgical conversion 81.608 (21.310, 141.906) 0.009 1.220 Association between procedure time and perioperative characteristics. Table 4 illustrates the relationship between intraoperative bleeding and its influencing factors. Age, history of previous pelvic surgery, pelvic adhesions, and surgical approach did not affect the amount of intraoperative bleeding. Even if there was a change in the surgical approach during the procedure, such as transitioning from transvaginal to transumbilical, it did not increase the amount of bleeding. However, for each 1 cm increase in tumor diameter, there was an 11.3 ml increase in intraoperative bleeding, with a statistically significant difference. Body mass index (BMI) showed a significant association with intraoperative bleeding, with a 7.5 ml increase for every unit increase in BMI (P = 0.02). Prolonged surgical time also indicated increased bleeding, with a 0.5 ml increase in bleeding for every minute of extended surgical duration, demonstrating statistical significance. Interestingly, in the vNOTES group, changing from the lithotomy position to the prone position resulted in a reduction of 16 ml in intraoperative bleeding, with a statistically significant difference (P = 0.02). Table 4 Association between operative bleeding and perioperative characteristics. Variables Beta 95% CI P-value VIF R 2  = 0.261 Age (year)  − 1.854 (− 3.965, 0.257) 0.084 1.095 Tumor size (cm) 11.349 (3.158, 19.539) 0.045 1.149 BMI (g/m 2 ) 7.497 (1.011, 13.983) 0.024 1.081 History of pelvic surgery  − 12.279 (− 47.152, 22.594) 0.485 1.082 Pelvic adhesions 14.729 (− 33.170, 62.628) 0.542 1.134 Abdominal-/vaginal-approach  − 6.303 (− 30.274, 17.668) 0.602 1.944 Prone-/lithotomy-position 16.011 (5.443, 26.579) 0.028 1.895 Surgical conversion 54.845 (− 66.753, 176.444) 0.371 1.347 Operative time 0.477 (0.019, 0.934) 0.041 1.326 Association between operative bleeding and perioperative characteristics. Table 5 presents the analysis results regarding factors influencing postoperative gas evacuation time. Age, tumor size, BMI, history of previous pelvic surgery, intraoperative adhesions, conversion surgery, intraoperative bleeding volume, and surgical duration did not affect postoperative gas evacuation time. However, on average, vNOTES surgery resulted in a 9 h earlier gas evacuation compared to LESS, with a statistically significant difference (P = 0.03). Even within the vNOTES group, patients placed in the prone position had a 5 h earlier gas evacuation compared to those in the lithotomy position, showing statistical significance (P = 0.01). Table 5 Association between exhaust time and perioperative characteristics. Variables Beta 95% CI P-value VIF R 2  = 0.185 Age (year)  − 0.060 (− 0.441, 0.320) 0.752 1.144 Tumor size (cm) 0.172 (− 1.860, 2.203) 0.867 1.183 BMI (g/m 2 )  − 0.015 (− 1.202, 1.173) 0.981 1.165 History of pelvic surgery  − 3.721 (− 9.895, 2.453) 0.233 1.089 Surgical conversion  − 5.926 (− 14.399, 2.547) 0.167 1.173 Abdominal-/vaginal-approach  − 9.237 (− 12.569, − 5.905) 0.035 1.852 Prone-/lithotomy-position 5.206 (1.500, 8.911) 0.016 1.805 Pelvic adhesions  − 12.751 (− 34.328, 8.826) 0.242 1.362 Operative time 1.359 (− 0.224, 2.942) 0.136 1.409 Operative bleeding 0.001 (− 0.041, 0.043) 0.963 1.354 Association between exhaust time and perioperative characteristics. Table 6 depicts the factors influencing postoperative analgesia. Among all perioperative factors, only the difference in surgical approach significantly affected the postoperative analgesic requirement. Analysis revealed that patients undergoing transvaginal surgery had a significantly reduced need for postoperative analgesia compared to those undergoing transumbilical surgery, with statistical significance (P = 0.07). Table 6 Association between postoperative analgesia and perioperative characteristics. Variables Exp(B) 95% CI P-value Age (year) 1.223 (0.784, 1.906) 0.374 Tumor size (cm) 1.095 (0.839, 1.431) 0.504 BMI (g/m 2 ) 0.434 (0.006, 2.232) 0.237 History of pelvic surgery 0.455 (0.065, 3.199) 0.429 Surgical conversion 0.883 (0.270, 2.886) 0.837 Abdominal-/vaginal-approach 0.258 (0.070, 1.917) 0.007 Prone-/lithotomy-position 1.013 (0.994, 1.033) 0.172 Pelvic adhesions 1.343 (0.363, 4.971) 0.659 Operative time 0.989 (0.975, 1.002) 0.108 Association between postoperative analgesia and perioperative characteristics.

This study collected data from 79 patients who underwent single-port laparoscopic surgery for the excision of individual posterior wall myomas at the Chengdu Women’s and Children’s Central Hospital from January 2022 to July 2023. This study has been approved by the Ethics Committee of the Chengdu Women’s and Children’s Central Hospital (No. 202130). And this study is also a comprehensive cohort investigation focusing on minimally invasive gynecological procedures conducted in Chengdu, China (Chinese clinical trial registration number ChiCTR2200059282). All methods were performed in accordance with the relevant guidelines and regulations. And informed consent was obtained from all participants. Research involving human research participants have been performed in accordance with the Declaration of Helsinki. The inclusion criteria for patients in both the single-port laparoscopy group and the vNOTES group involved providing thorough information about the surgical procedure and associated risks, after which patients made their own choices. To minimize bias, all surgeries were performed by the same surgeon. Inclusion criteria for patients required: no history of previous surgeries such as endometriosis or pelvic abscess, presence of a single myoma located in the posterior wall, necessitating myomectomy, myoma diameter between 4 and 8 cm, and exclusion if malignancy was suspected. We collected patients’ general information, including age, body mass index (BMI), maximum diameter of myoma, history of dysmenorrhea, hypertension, diabetes, previous surgical history, and obstetric history. The primary outcome was the surgical duration, defined as the time from skin or vaginal mucosa incision to the completion of the final suture. Secondary outcomes included intraoperative blood loss, degree of postoperative hemoglobin decrease, use of postoperative analgesics, time to flatus, length of hospital stay, and perioperative complications (intraoperative injury, conversion to another surgical method, infection, and reoperation). Intraoperative blood loss was estimated by the anesthetist. Length of hospital stay was defined as the time from the day of surgery to discharge. The surgical instruments used included disposable wound retractors and multi-channel single-port protective sleeves (Hangzhou Kangji Medical Devices Co., Ltd.), as well as the Storz company laparoscopic system and conventional laparoscopic instruments. In the single-port laparoscopic group, a longitudinal incision of 2 cm in diameter was made at the umbilicus. For the vNOTES-L group (lithotomy position) and vNOTES-P group (prone position), a 2 cm incision was made at the posterior fornix of the vagina to enter the abdominal cavity. Specific positioning and standard entry procedures can be found in our previous study 6 . CO 2 was used to establish pneumoperitoneum, with a pressure setting of 14 mmHg. The specific surgical process involved first exploring the pelvic and abdominal cavities, separating adhesions, and exposing the surgical field. A 1:10,000 adrenaline injection was administered into the uterine muscle wall, followed by monopolar incision of the uterine muscle layer and pseudo-capsule. After myoma enucleation, the tumor cavity was closed in two layers using 2-0 absorbable barbed sutures. Following confirmation of no bleeding or hematoma, the LESS group underwent continuous closure of the peritoneum and rectus abdominis fascia with 2-0 absorbable sutures, interrupted suturing of subcutaneous tissue with three stitches, and intradermal closure of skin tissue with 4-0 absorbable sutures. The vNOTES group employed 2-0 absorbable barbed sutures to close the posterior fornix of the vagina and peritoneal tissue. Statistical analyses were performed using SPSS software (version 27.0; IBM Corp., Armonk, NY, USA). Fisher’s exact test or the chi-square test was employed to analyze categorical data, reported as counts (percentages). The mean ± standard deviation of continuous variables was assessed using student’s t -test and least significant difference student’s t -test. Multifactorial linear regression analysis was conducted to identify factors influencing intraoperative bleeding, surgical duration, and postoperative flatus time. Binary logistic regression analysis was utilized to explore the association between preoperative characteristics and postoperative analgesic use. Covariates were selected based on different variables in univariate analysis and factors reported as influencing dependent variables in previous studies. Statistical significance was set at P < 0.05 for all analyses, using a two-tailed test.

In recent years, the concept of ERAS has been widely promoted and applied. Its core principle is to optimize perioperative care measures, reduce the stress response caused by perioperative care and surgical treatment, and promote rapid patient recovery 7 . The concept of ERAS was initially applied in gastrointestinal surgery and has gradually been extended to ophthalmology, gynecology, cardiac surgery, among other fields, with its effectiveness confirmed 8 . Previous studies have mostly focused on accelerating postoperative recovery by transforming perioperative care models. However, strategies to promote postoperative recovery not only involve optimizing nursing measures but also include minimally invasive surgical approaches, such as changes in surgical approach, which are crucial for accelerating postoperative recovery 9 . Hence, single-incision laparoscopy has emerged, reducing the number of abdominal incisions or even eliminating them entirely, providing patients with a more aesthetically pleasing experience and minimizing surgical stress both psychologically and physiologically. Currently, the prevailing surgical approach for uterine fibroid excision is LESS. However, single-incision laparoscopy inherently presents operational limitations, such as instrument interference and restricted visualization. In the resection of posterior wall fibroids, LESS places higher demands on the surgeon. This is due to the increased distance between the surgical site and the navel, exacerbating the “chopstick effect”. However, vNOTES, benefiting from its closer proximity to the target organ and the greater expansibility of the vaginal route compared to the umbilical route, can largely offset the disadvantages of LESS 10 . Moreover, as demonstrated in our previous study 11 , vNOTES uterine fibroid resection can be performed as a routine procedure. Furthermore, in this study, we were delighted to find that the prone position for fibroid resection resulted in shorter surgical times compared to the bladder flap position. Despite the consistent surgical approach, the change in position enables a transition from the backhand suturing technique to the forehand technique for suturing posterior wall fibroids. This not only reduces surgical time but also ensures the effectiveness of the suturing. The advantage of prone position uterine fibroid resection extends beyond merely shortening surgical time. Alongside reduced surgical duration, it can also mitigate intraoperative bleeding. Controlling intraoperative blood loss is a pivotal focus of implementing enhanced recovery after surgery (ERAS) protocols. Prior research has demonstrated various methods, such as posterior pituitary injection, barbed suture closure, and uterine artery ligation, to reduce intraoperative bleeding during fibroid resection 12 – 14 . Our study confirms that altering the surgical approach and patient positioning is not solely aimed at enhancing surgeon comfort and reducing technical demands but primarily aims to ensure patient safety. By minimizing surgical time, decreasing intraoperative bleeding, reducing anesthesia usage, and mitigating patient intraoperative hypothermia, ERAS recommendations can be met 9 . Postoperative gas evacuation time and frequency of analgesic drug usage are two crucial indicators for assessing postoperative recovery. With the vNOTES approach, the uterus is positioned beneath the intestines, eliminating the need for repeated traction on the intestines for exposure. Moreover, surgical manipulation is concentrated in the lower abdomen, minimizing the impact on bowel function. Previous studies have demonstrated that vNOTES patients experience earlier postoperative gas evacuation, facilitating the potential for day surgery even in cases of total hysterectomy 15 . Consistent with our previous research findings 16 , patients undergoing uterine fibroid resection via vNOTES exhibited significantly lower postoperative visual analogue scale (VAS) scores compared to those undergoing LESS surgery. This similarity in our study results suggests that milder postoperative pain leads to reduced analgesic drug consumption. Analyzing the reasons behind this, firstly, the innervation near the vaginal vault is provided by visceral nerves, resulting in significantly reduced postoperative pain compared to traditional cutaneous incisions 17 . Secondly, compared to LESS, vNOTES exhibits lower pain scores, possibly due to the absence of abdominal wall incisions 18 . However, some scholars suggest that this may also be attributed to the fact that vNOTES procedures do not require manipulation of the uterine ligaments 19 . Complications of vNOTES surgery include injuries to surrounding organs such as the intestines and bladder, blood loss exceeding 500 ml, and postoperative infections in the urinary tract and other areas. In our study, one patient in the vNOTES-L group experienced rectal injury due to severe adhesions caused by concomitant endometriosis. Previous studies have shown that transvaginal vault incision is a traditional surgical approach that provides safe access to the abdominal cavity, with a complication rate of only 1.3% 20 . In our previous research involving 2000 cases of vNOTES procedures, the incidence of visceral injury was as low as 0.4% 21 . Therefore, vNOTES can be routinely performed in gynecological surgeries and aligns with the principles of ERAS. Regarding postoperative infections, it is undeniable that converting a class I incision to a class II incision increases the risk of infection and antibiotic usage. This is an issue that cannot be overlooked in our exploration process. However, regarding the increased risk of postoperative infections and other vNOTES perioperative complications, we have shared valuable experiences from our medical center in previous studies and provided detailed recommendations 21 . Currently, vNOTES has entered a period of rapid development, with growing enthusiasm for its adoption and its concepts becoming increasingly ingrained. At this stage, innovation in surgical techniques must be combined with patient preferences. For gynecologists, besides focusing on safely completing surgeries, attention should also be given to reducing surgical morbidity and accelerating postoperative recovery, such as ERAS 22 . vNOTES represents a new practice in minimally invasive surgery and is worthy of application and promotion in gynecological clinical practice, harnessing its clinical value and potential applications. This pilot study has advanced our understanding of the prone and lithotomy positions in posterior myoma removal via vNOTES. However, several limitations must be acknowledged. Firstly, the sample size in this study was relatively small compared to similar investigations employing Multiport and LESS techniques. Secondly, this study is retrospective; conducting prospective studies with larger sample sizes would better validate the reliability of the findings. Therefore, large-scale multicenter studies encompassing a broader range of patients, extended follow-up periods, and diverse surgical procedures are imperative to further advance the widespread adoption of vNOTES within the field of gynecology.

This study demonstrates that the application of vNOTES technique in uterine fibroid resection is safe and feasible. Compared to LESS, vNOTES shows significant advantages in alleviating postoperative pain, shortening postoperative gas evacuation time, and improving cosmetic outcomes. Particularly, vNOTES-P for posterior uterine fibroid resection, as an emerging surgical approach, offers certain advantages in facilitating surgical maneuverability and reducing operative time, rendering it more suitable for posterior uterine fibroid resection.

Uterine leiomyomas are among the most common benign tumors of the female reproductive system, with an incidence rate reaching up to 70% 1 . In the early stages, uterine leiomyomas often present with no noticeable symptoms, with most cases being detected during gynecological examinations. However, as the size of the leiomyomas increases, patients may experience various clinical manifestations depending on the location of the tumors, such as abnormal uterine bleeding, infertility, abdominal distension, and compression symptoms (difficulty in urination or defecation), significantly impacting the patients’ quality of life 2 . The treatment strategies for uterine leiomyomas encompass medication, interventional embolization, HIFI ultrasound ablation, and surgical interventions. Among these, myomectomy is the preferred treatment option for patients desiring to preserve fertility. To adhere to the principles of postoperative rapid recovery, we advocate for the use of natural orifice transluminal endoscopic surgery (NOTES) as the standard approach for myomectomy. Compared to open surgery and traditional multi-port laparoscopy, single-port laparoscopy offers advantages such as reduced postoperative pain, earlier flatus, shorter hospital stays, and improved cosmetic outcomes 3 , 4 , aligning more closely with the concept of enhanced recovery after surgery (ERAS). Additionally, the use of a larger entry route during surgery allows for complete specimen retrieval, minimizing the risk of specimen omission and tumor dissemination associated with morcellation 5 . Existing NOTES procedures are divided into laparoendoscopic single-site (LESS) and vNOTES. Regardless of whether a transumbilical or transvaginal approach is employed, the excision and suturing of posterior wall myomas have always posed a challenge for surgeons. Effectively and quickly suturing the cavity of posterior wall myomas to reduce intraoperative bleeding and postoperative hematoma formation is a focal point in gynecological surgical decision-making. Our research team pioneered the use of the prone position for vNOTES posterior uterine fibroid resection 6 . This approach combines the advantages of single-port laparoscopy while allowing for downward suturing to close the cavity, thus avoiding the disadvantage of uterine retroversion due to gravity in the lithotomy position, which can interfere with exposure and suturing during surgery. To compare which approach for excising posterior wall myomas aligns better with the current ERAS concept, we conducted a prospective study.

Supplementary Information. Supplementary Information.