Aspects on the use of robotic-assisted surgery in benign gynecology

Background and methods: Robotic surgery has rapidly increased in gynecology since FDA approval in 2005. In Sweden, 20/50 gynecological departments and 44 robotic systems are used for malignant and benign gynecological procedures. Previous studies reported patients benefit from minimally invasive surgery (MIS) compared to open abdominal surgery. Moreover, robotic surgery has not shown a higher complication rate than other MIS procedures. However, scientific evidence demonstrating the advantages of robotic surgery over other surgical procedures has not been definitively established in benign gynecology. Several small observational cohort studies were conducted at the beginning of the robotic era, and some randomized controlled studies had been published, but often with small cohorts and skilled surgeons with high surgical volumes. Because Sweden has high coverage and quality national registers, we decided to perform several extensive observational register studies to continue the study of robotic surgery in benign gynecology. Prospectively collected data were retrieved from three Swedish national registers. The overall aim of this thesis was to study whether women with benign gynecological disease and perioperative complicating factors would profit from robotic surgery in short- and long-term outcomes.

Study I: Of 10,288 women who had a total hysterectomy from 2015-2017, we identified 2,787 (27.1%) with normal weight and 1,535 (14.9%) with obesity (BMI ≥ 30). One year after hysterectomy, the frequency of complications was higher in women with obesity compared to women with normal weight (adjusted odds ratio (aOR) 1.4, 95% confidence interval (CI) 1.1- 1.8). In women with obesity abdominal hysterectomy (AH) was associated with a higher overall complication rate (aOR 1.8, 95% CI 1.2-2.6) and vaginal hysterectomy (VH) had a slightly higher risk of intraoperative complications (aOR 4.4, 95% CI 1.2 -15.8) compared to robotic-assisted total laparoscopic hysterectomy (RATLH). Women with obesity had a higher rate of conversion to AH with conventional minimally invasive hysterectomy (TLH: aOR 28.2, 95% CI 6.4-124.7 and VH: 17.1, 95% CI 3.5-83.8) compared to RATLH. Finally, in obese women AH, TLH and VH were associated with a higher risk of blood loss >500 ml than in RATLH (AH: aOR 11.8, 95% CI 3.4-40.5, TLH: 8.5, 95% CI 2.5-29.5 and VH: 5.8, 95% CI 1.5-22.8).

Study II: 8,747 hysterectomized patients were included in the study; of these, 1,166 (13.3%) with endometriosis were compared to 7,581 (86.7%) without endometriosis. Patients with endometriosis had a higher proportion of complications (aOR 1.2, 95% CI 1.0-1.4), were more often converted to abdominal hysterectomy (aOR 1.7, 95% CI 1.1-2.6), had higher estimated blood loss (EBL) (>500 ml; aOR 3.1, 95% CI 2.2-4.4) and a longer operative time (>2 hours; aOR 4.3, 95% CI 2.7-6.6) than endometriosis-free patients. The conversion rate was 13.8 times higher in TLH than in RATLH (aOR 13.8, 95% CI 3.6-52.4).

Study III: TLH was associated with a higher rate of intraoperative complications (aOR 2.8, 95% CI 1.3- 5.8) and postoperative bleeding complications (aOR 1.8, 95% CI 1.2-2.9) compared to RATLH. Intraoperative data showed a higher conversion rate (aOR 13.5, 95% CI 7.2-25.4), higher blood loss (>500 ml aOR 7.6, 95% CI 4.0-14.6) and longer operative time (>2 hours aOR 47.6, 95% CI 27.9-81.1) in TLH compared to RATLH. The TLH group had a lower caseload per year than the RATLH group. Higher surgical volume was associated with lower median blood loss, shorter operative time, lower conversion rate and lower perioperative complication rate. Differences in conversion rate or operative time were not affected by surgeon volume in RATLH compared to TLH.

Study IV: Between 2012 and 2015, 14,682 patients in Sweden were hysterectomized for benign conditions and 1,074 (7.3%) patients were identified in the GynOp register with endometriosis. The prevalence of prescription analgesics was higher in women with endometriosis than those without (OR 2.2, 95% CI 1.7-2.9). In women with endometriosis, prescribed analgesics (OR 1.0, 95% CI 0.8-1.2) did not decrease 3 years after hysterectomy compared to 3 years before surgery. There was also a significantly higher rate of prescribed psychoactive (OR 1.6, 95% CI 1.4-2.0) and neuroactive (OR 1.9, 95% CI 1.3-2.7) drugs at the long-term post-surgery follow-up. Choice of operation mode (AH, TLH or RATLH) did not affect long-term consumption of pain-modifying drugs.

Studies V and VI: In Studies V and VI 9,967 patients who underwent surgery for an apical prolapse, defined as point C ≥-1 cm to the hymen (stage II prolapse or worse), were identified from the GynOp register between 1 January 2015 and 31 December 2018. Of these 9,967 patients, 8,155 (82%) had a uterine prolapse (Study V) and 1,812 (18%) had a vaginal vault prolapse before surgery (Study VI). Study V: Compared to the Manchester procedure (MP), sacrospinous hysteropexy (SSHP) without graft and sacrohysteropexy (SHP) were associated with a significantly higher rate of recurrent pelvic organ prolapse (POP) surgery (SSHP: aOR 2.6, 95% CI 2.0-3.5; SHP: aOR 2.6, 95% CI 1.8-3.7) and patients describing a sense of globe (SSHP: aOR 2.0, 95% CI 1.6- 2.6; SHP: aOR 1.8, 95% CI 1.1-3.1). No difference was noted in the reoperation rate or sense of globe between vaginal graft with SSHP and MP with fixation to the uterosacral ligaments. Patients undergoing SSHP without graft had a higher frequency of 1-year postoperative complications compared to MP (aOR 2.0, 95% CI 1.6-2.6) and SHP (aOR 2.4, 95% CI 1.4-3.9). Moreover, the frequency of 1-year postoperative complications was higher in SSHP with graft (aOR 1.6, 95% CI 1.1-2.2) than in MP. Study VI: In patients with vaginal vault prolapse a significantly higher proportion of patients undergoing recurrent POP surgery was seen in SSLF without graft compared to SSLF with graft (aOR 2.2, 95% CI 1.4-3.6). Patient-reported sensation of vaginal bulging 1 year after surgery was higher in the SSLF group without graft than in the SSLF group with graft (aOR 1.9, 95% CI 1.3-2.8) and the sacrocolpopexy (SCP) /sacrocervicopexy (SCerP) group (aOR 2.0, 95% CI 1.1-3.4). Finally, we found a significantly higher rate of complications 1 year after surgery in SSLF without graft (aOR 2.3, 95% CI 1.2-4.2) and SSLF with graft (aOR 2.2, 95% CI 1.2-4.2) compared to SCP/SCerP.

Conclusion: Robotic hysterectomy shows a better peri- and postoperative outcome than AH and TLH in benign gynecology. This superiority of robotic hysterectomy is most evident in patients with complicating factors, such as obesity and endometriosis. These patients will profit more from RATLH than TLH due to the lower risk of conversion and shorter operative time. Surgeon volume does not seem to have any effect on these outcomes. In long-term outcomes (such as pain in endometriosis patients) hysterectomy may not help at all, as the number of patients consuming analgesics did not decrease 3 years after surgery. Apparently, surgical method does not impact this outcome. In vaginal vault prolapse SCP has the lowest number of complications 1 year after surgery. However, in uterine prolapse MP with uterosacral fixation should be the first choice if childbearing is complete because of its low recurrence rate and low morbidity. Moreover, SCP/SCerP and SHP show a higher recurrent POP surgery rate and a higher subjective relapse rate in Sweden than in international studies. It is unclear whether there is a need for robotic surgery in POP.

List of scientific papers

I. Brunes M, Johanneson U, Häbel H, Söderberg MW, Ek M. Effects of obesity on peri- and postoperative outcomes in patients undergoing robotic versus conventional hysterectomy. J Minim Invasive Gynecol. 2021 Feb;28(2):228-236.
https://doi.org/10.1016/j.jmig.2020.04.038

II. Brunes M, Johannesson U, Häbel H, Forsgren C, Moawad G, Ek M. Peri- and postoperative outcomes in patients with endometriosis undergoing hysterectomy. [Accepted]
https://doi.org/10.1016/j.ejogrb.2022.02.180

III. Brunes M, Forsgren C, Warnqvist A, Ek M, Johannesson U. Assessment of surgeon and hospital volume for robot-assisted and laparoscopic benign hysterectomy in Sweden. Acta Obstet Gynecol Scand. 2021 Sep;100(9):1730- 1739.
https://doi.org/10.1111/aogs.14166

IV. Brunes M, Altman D, Pålsson M, Söderberg MW, Ek M. Impact of hysterectomy on analgesic, psychoactive and neuroactive drug use in women with endometriosis: nationwide cohort study. BJOG. 2021 Apr;128(5):846-855.
https://doi.org/10.1111/1471-0528.16469

V. Brunes M, Johannesson U, Drca A, Bergman I, Söderberg MW, Warnqvist A, Ek M. Recurrent surgery in uterine prolapse: A nationwide register study. [Accepted]
https://doi.org/10.1111/aogs.14340

VI. Brunes M, Ek M, Drca A, Söderberg MW, Bergman I, Warnqvist A, Johannesson U. Vaginal vault prolapse and recurrent surgery: A nationwide observational cohort study. [Accepted]
https://doi.org/10.1111/aogs.14341