Route of Hysterectomy: Robotic

Introduction

Approximately 600,000 hysterectomies are performed annually in the United States, with the majority for benign indications. ¹ Hysterectomy can be performed abdominally, vaginally, laparoscopically, or laparoscopically with robotic assistance. Many societies support approaching hysterectomy in the most minimally invasive fashion.^1–3 Laparoscopy for benign hysterectomy was first introduced in the 1980s with the hope that this minimally invasive approach would be an alternative to abdominal hysterectomy for cases not amenable to a vaginal route. A 2002 study evaluating type of hysterectomy from 1990 to 1997 found a 30-fold increase in laparoscopic hysterectomy over that study period; however, at the end of the period, the majority of hysterectomies were still performed abdominally(63%), with 23% performed vaginally, and only 10% performed laparoscopically. ⁴ This was despite findings that vaginal and laparoscopic approaches to hysterectomy were associated with shorter lengths of hospital stay, compared to abdominal hysterectomy. ⁴

Factors attributed to surgeons not rapidly adopting laparoscopic techniques included diluted training experiences during residency, lack of proctors and mentor surgeons for younger surgeons out of training, and lengthy learning curves required to develop new surgical skills that involved use of rigid instruments with a 2-dimentional camera that required counterintuitive surgical maneuvering.^5,6 The advent of robotic surgery provided the opportunity to change the surgical environment radically.

Robotic Surgery Platform

Robotic-assisted laparoscopy is a variation of conventional laparoscopic techniques. The robotic platform from Intuitive Surgical Inc., Sunnyvale, CA, the da Vinci Surgical System, is the first telesurgical system approved by the U.S. Food and Drug Administration (FDA). ⁷ Gynecologic indications for robotic use were approved in 2005. ⁷ The da Vinci surgical system is the only FDA-approved robotic platform on the market and, through the years, has undergone several technologic iterations. All systems have a patient cart, surgeon console, and 3-dimensional (3D) camera. The 3D camera provides a precise panoramic view of the surgical site with accurate depth perception and multiple degrees of magnification. The original system progressed from a 3-arm to a 4-arm system. The da Vinci S model added high definition to the 3D camera, decreased the bulky architecture, and provided an easier set-up. ⁸ The da Vinci Si provided further visual enhancements with near-infrared fluorescence imaging and added a second console for trainee teaching.^7,8 The da Vinci Xi provided laser targeting and further architectural changes with overhead mounted arms.^7,8 The da Vinci SP platform for single-port applications has been available since 2014. However, at this time, gynecologic applications have not yet been approved by the FDA.

Robotic Training and Utilization

Compared to conventional laparoscopy, robotic surgery provides the surgeon with 3D visualization, enables joint-wristed instrumentation with tremor control, and imparts improved ergonomics for the surgeon. In addition to the ergonomic advantage of being able to sit while operating, the surgeon has the capability to adjust the armrests and foot-pedals in addition to the tilt and height of the console headrest. These individualized settings are then stored in the console for subsequent use by the surgeon. The fulcrum effect of conventional laparoscopic instruments is eliminated as robotic instrumentation has 7° of movement. Robotic surgery is unique in that the primary surgeon is not beside the patient but, instead, operates at a console remote from the patient. For robot-assisted surgery to be successful, attention must be placed on proper patient positioning, robotic port placement, and docking.

Optimal patient positioning enables the surgeon to have access to the pelvis, decreases injury, and maximizes robotic-arm movement. Once the robotic arms are docked to the ports, the patient should not be moved as this is associated with intraoperative complications. However, tables that are paired with the robot do enable positional changes of the patient. Compared to conventional laparoscopy, a steeper degree of Trendelenburg may be utilized for robotic surgery.^9,10 Given this steep angle, care must be taken to prevent patient slide.

Learning robotic-assisted surgery is different from learning conventional laparoscopy. The surgeon sits at the console and must coordinate multiple foot pedals, while using wrist controls to control the 3 robotic arms and camera. Lack of force feedback is a drawback of robotic surgery. Despite this complexity, robotic surgical techniques mimic those of an open procedure, and surgeons report a faster learning curve for robotic surgery, compared to that for conventional laparoscopic surgery. ⁶ Studies have suggested that a learning curve of 50 robotic hysterectomies is needed to reach optimization.^5,7,11

Intuitive Surgical's da Vinci Training Passport program provides tiered industry-sponsored training. A 2020 article outlines the effectiveness of the Fundamentals of Robotic Surgery (FRS) skills curriculum. ¹² This is a multidisciplinary proficiency-based progression curriculum for basic robotic surgical skills, independent of a specific robotic company's platform, that was developed for teaching residents and fellows and included the specialties of urology, gynecology, colorectal surgery, general surgery, and thoracic surgery. ¹² Gynecologic societies do not currently have a standardized credentialing process. This forces hospital systems, guided by societies such as the American Association of Gynecologic Laparoscopists, to determine criteria for robotic training modules and simulation, mentoring, proctoring, privileging, and maintenance of skills. ⁷

Robotic systems with dual consoles have elevated the training process in residency and fellowship programs, allowing both surgeons and trainees to operate simultaneously. This is an improvement over verbal direction and use of the telestration screen. ¹¹ The robotic platform, aided by use of dual-console technology might facilitate more-efficient learning and adoption of minimally invasive surgical techniques for novice surgeons. ⁷ The most-recent data for United States inpatient hysterectomy trends from 1998 to 2010 indicated that, in 2010, abdominal hysterectomy was still the most-common approach to benign hysterectomy. ¹³ When the data was stratified by year, abdominal hysterectomy accounted for 65% of approaches in 1998, reaching a peak of 68.9% in 2002 and then declined to 54.2% in 2010. Vaginal hysterectomy declined continuously from 24.8 % in 1998 to 16.7% in 2010. Conventional laparoscopic hysterectomy reached a peak of 15.5% in 2006 and then declined to 8.6 % in 2010, while robotic hysterectomy accounted for 0.9 % of cases in 2008 with an upward trend to 8.2% at the end of the study period in 2010. ¹³ The more rapid incorporation of robotic surgery into the gynecologic surgeon's armamentarium has continued to decrease the percentage of benign hysterectomies approached via laparotomy.

Robotic Surgery Outcomes

Regarding patient-centered outcomes, the main difference between minimally invasive and open hysterectomy is a shorter return to regular activity with vaginal and laparoscopic approaches. ¹⁴ The Center for Medicare and Medicaid Services has recommended use of readmission within 30 days from a previous admission as a quality-outcomes metric. A cohort study of patients undergoing benign hysterectomy over a 5-year period found that patients who underwent robotic-assisted laparoscopic hysterectomy had a significantly lower chance of readmission <30 days after surgery, compared to patients who underwent laparoscopic, abdominal, and vaginal hysterectomies. ¹⁵

In addition, the researchers also found significant benefits including lower estimated blood loss, shorter lengths of stay (LOS), and lower readmission costs in the robotic group, compared to the other 3 groups. ¹⁵ A systematic review of a robotic approach to hysterectomy, compared to laparotomy, for benign disease found a shorter LOS and lower blood loss. ¹⁶ An updated 2019 Cochrane Review found comparable rates of intraoperative and postoperative complications between robotic and conventional laparoscopic hysterectomy, with the robotic approach having an average longer operating time but a shorter LOS. ¹⁷ A shorter LOS in the robotic group was confirmed further in a study of more than 32,000 cases comparing outcomes of open, vaginal, laparoscopic, and robotic hysterectomy. This occurred despite the robotic cohort having higher rates of adhesive disease, uteri >250 g, and morbid obesity. ¹⁸

A growing number of women in the United States are overweight, with 43% of women undergoing benign hysterectomy meeting the definition of obesity with a body mass index (BMI) of ≥30 kg/m². ¹⁹ Increasing BMI is known to be associated with longer operative times and increased estimated blood loss (EBL). A recent retrospective cohort study evaluated the impact of route of benign hysterectomy and postoperative morbidity stratified by BMI. ¹⁹ The World Health Organization classification for underweight (BMI <18.5 kg/m²), class 1 obesity (BMI 30–34.9 kg/m²), class 2 obesity (35–39.9 kg/m²), and class 3 obesity (BMI ≥40 kg/m²) was used for BMI stratification. ¹⁹ More than 159,000 cases of benign laparoscopic and abdominal (laparotomy) hysterectomies were abstracted from the American College of Surgeons National Safety and Quality Improvement program from 2005 to 2016. When stratified by BMI, patients who underwent abdominal hysterectomy had an increase in composite morbidity with a BMI of >30 kg/m², and the increase followed a linear upward trend with increasing BMI. Interestingly, underweight women, with BMIs <18.5 kg/m² also had a significant increase in several postoperative morbidity outcomes. ¹⁹ For laparoscopic hysterectomy, composite morbidity was not significantly different until BMI became >40 kg/m². ¹⁹

Overall, abdominal hysterectomy, compared to laparoscopic hysterectomy had significantly higher composite postoperative morbidity, with increases in wound complications, 30-day reoperations, 30-day readmissions, and sepsis-related events. ¹⁹ It should be noted that robotic and conventional laparoscopic hysterectomy cases could not be differentiated in this analysis secondary to the lack of dedicated robot-specific codes in this large, national database. ¹⁹

The conversion rate from laparoscopic to open hysterectomy for benign cases might be as high as 19%. ²⁰ Reported risk factors for conversion include increasing age, BMI, history of previous abdominopelvic surgery, adhesive disease, endometriosis, leiomyomata, uterine weight, and low-volume surgeons. ²⁰ A retrospective cohort analysis of a multicenter Michigan database of almost 7000 women undergoing benign hysterectomy found a sevenfold reduction in the odds of conversion to laparotomy with use of the robotic platform compared to conventional laparoscopy. ²⁰ A recent study with data collected from 3 Swedish population-based registers evaluated if obesity increased morbidity and complication rates and if hysterectomy mode affected the outcomes. ²¹ Hysterectomy mode was classified as open abdominal hysterectomy, conventional laparoscopic hysterectomy (including total laparoscopic and laparoscopic-assisted vaginal hysterectomy), vaginal hysterectomy, and robotic-assisted laparoscopic hysterectomy. ²¹ The researchers suggested that robotic-assisted laparoscopic hysterectomy could lower the risk of conversion rates and intraoperative bleeding in obese women, compared to other modes of hysterectomy. ²¹

These findings are consistent with an earlier US multicenter analysis comparing robotic, open, laparoscopic, and vaginal benign hysterectomies performed by high-volume surgeons whereby the robotic approach resulted in fewer intraoperative complications and significantly fewer postoperative complications. ¹⁸

Robotic Surgery Costs

The cost of the robotic platform has been of concern, even as the market for robotic surgery continues to expand. Gynecologic applications for robotic surgery increased from 123,000 cases in 2010 to 252,000 cases in 2017. ²² The initial cost to purchase the robotic console is high. A report estimating the operating cost of robotic surgery in 2017 yielded a cost per procedure of $3,568. This included $1,866 for instruments and accessories; $1,038 applied to the purchase of the robotic system; and $663 for the service contract (robot maintenance). ²² Robotic surgery, on average, costs an additional $2,000–$3,000, compared to other approaches. ²³

Cost analyses are subject to bias, and many studies do not include the original acquisition cost and maintenance fees associated with conventional laparoscopic equipment. ²³ Length of surgery and surgical complications decrease with increased robotic-platform surgical experience, and these factors, combined with shorter a LOS might offset the overall costs associated with the robot.^18,20,22,23 Shorter LOS could lead to less time off from work for patients and earlier returns to regular activities, resulting in quicker returns to productivity and higher quality of life.^18,23 Teamwork is the key to a successful robotics program. A dedicated robotic operating-room (OR) staff is paramount to efficiency in robotic set-up and room turnover. ²³ An experienced bedside assistant optimizes the robotic procedure, resulting in improved OR flow and time. ⁷

Conclusions

Choice of hysterectomy route should be individualized. Factors that affect route of surgery include indication for surgery along with uterine size and pathology, pelvic anatomy, and vaginal access. Patient preference, surgeon competence, preference, and availability of resources all factor into the decision-making process. The literature has shown that minimally invasive approaches to benign hysterectomy shorten LOS and minimize postsurgical complications, compared to more-invasive open approaches. ²⁴ Proceeding in a minimally invasive fashion has allowed a transition from inpatient to outpatient hysterectomies. The change in approach to hysterectomy was noted in the first 3 years after introduction of the new platform, with the number of robotic surgeries increasing while the number of abdominal hysterectomies decreased simultaneously.

Clinical algorithms have been proposed to assist surgeons in determining the most-appropriate route of hysterectomy, with vaginal hysterectomy being the preferential choice if possible.^1–3 When vaginal surgery is not possible, surgeons should consider laparoscopic and robotic approaches prior to open surgery. In reality, unless surgeons are facile in all routes of hysterectomy, they will likely default to the method with which they are most comfortable. ¹⁴ A 2020 study found that overall surgical numbers decreased for obstetrics and gynecology residents with half of residency graduates not able to meet the minimum recommendation of 70 minimally invasive hysterectomies. ²⁵ The shorter learning curve of robotic versus other minimally invasive hysterectomy approaches has led to the rapid adoption of this technology. The robotic platform provides a method for gynecologic surgeons to avoid laparotomy and continue with a minimally invasive approach to hysterectomy. Furthermore, robotic approaches versus conventional laparoscopic ones can benefit patients with large uteri, complex pathologies, or morbid obesity.^7,14,21,23

Several new robotic companies have entered the market with platforms that have the ability to provide reusable instruments, provide haptic feedback, allow camera control via tracking of surgeon eye movements, and provide modular designs allowing placement of individual arms. ⁷ It is hoped that this market competition will also result in decreased robotic costs. In addition, improved perioperative outcomes with robotic benign hysterectomy and lower rates of conversion to open procedures can translate into reductions in overall economic impact of treatment, including less need for additional surgical or medical treatment and potentially less time lost from work and regular activity.^18,20 Advancement in surgical technology is inevitable; as robotic surgery evolves and more companies enter the realm of minimally invasive surgical technology, the field will advance, providing benefits to both patients and surgeons.