• cost analysis;
  • economics;
  • gynecologic surgery;
  • healthcare cost;
  • robotic surgery


  1. Top of page
  2. Abstract
  3. Obese Patients and those with Endometrial Cancer may Benefit from Robotic Surgery
  4. Conclusions
  5. Disclosure
  6. References

Since the introduction of robotic technology, there have been significant changes to the field of gynecology. The number of minimally invasive procedures has drastically increased, with robotic procedures rising remarkably. To date several authors have published cost analyses demonstrating that robotic hysterectomy for benign and oncologic indications is more costly compared to the laparoscopic approach. Despite being more expensive than laparoscopy, other studies have found robotics to be less expensive and more effective than laparotomy. In this review, controversies surrounding cost-effectiveness studies are explored.

To date several authors have published cost analyses demonstrating that robotic hysterectomy for benign and oncologic indications is more costly compared to the laparoscopic approach.[1-4] Wright et al. published the most robust cost model to date comparing the cost of hysterectomy according to approach: laparoscopic versus robotic.[1] Reviewing 264 758 hysterectomies for benign indication at 411 hospitals, the authors demonstrated that patients undergoing robotic hysterectomy experienced similar morbidity compared to patients undergoing laparoscopic hysterectomy. The robotic approach was associated with $2189 in additional cost compared to laparoscopy. Despite being more expensive than laparoscopy, other studies have found robotics to be less expensive and more effective than laparotomy.[5] Wright's study is landmark given its size, the incorporation of fixed costs of acquiring and maintaining the robot, and the use of propensity score matching to address treatment allocation bias inherent to retrospective, non-randomized cohort studies.

Despite the results of cost-effectiveness studies, several unanswered questions remain. Among them:

  1. How has the absence of large randomized controlled trials (RCT) affected the quality of data available to evaluate robotic surgery?
  2. Is there a subset of gynecologic patients for whom robotic surgery provides better outcomes compared to laparoscopy and laparotomy?
  3. What effect has the deployment of robotic surgery had on laparoscopic training?
  4. Are the current costs of robotics immutable, or would a change in willingness-to-pay or the entry of a competitor be sufficient to make robotic surgery cost equivalent with laparoscopy?

The answers to these questions have the potential to complicate our response to emerging cost data regarding robotics in gynecology. This review aims to explore these questions.

An absence of randomized data

The use of RCT where clinical equipoise exists is central to the modern tenet of evidence-based medicine. There is paucity in the quantity and quality of RCT in surgery. Occasionally, pressure, either extrinsic or intrinsic, to introduce technology overcomes the restraint and collective effort required to perform RCT and technologies or novel surgical techniques are deployed without evidence proving their benefit. The intra-aortic balloon pump for the treatment of cardiogenic shock is one such technology that was deployed without rigorous RCT given widely shared beliefs in logic behind its theoretical benefit. After years of clinical use and entrenched provider bias preventing post-market RCT, Thiel et al. published a landmark RCT demonstrating that the use of the intra-aortic balloon pump is not superior to supportive care among intensive care unit patients with cardiogenic shock.[6]

Although the stakes are not nearly as high, robotic surgery was introduced into the surgical arena with a similar lack of pre-clinical randomized trials with early adopters convinced of its theoretical benefit.[7] With nearly 10 years of clinical experience, the likelihood of meaningful RCT comparing the robotic approach to laparoscopy and laparotomy diminishes as providers develop practice bias. While retrospective studies are helpful in comparing robotics to other modalities, the very same biases, which become impediments to RCT, complicate the interpretation of retrospective studies.

Provider bias regarding the allocation of patients to the robotic versus laparoscopic versus open approach introduces the potential for confounding, which would otherwise be avoided through RCT. The remedy for confounding in retrospective studies includes matched cohort analysis and propensity score matched analysis. However, once matched, the criteria used for matching can no longer be examined for association with study outcomes. For example, once matched for body mass index (BMI), BMI should no longer be evaluated as a predictor of outcome in retrospective studies regarding robotics. While stratified analyses provide a potential solution to this problem, prospective randomized controlled trials powered to allow sub-group analysis remain the gold standard.

Then again, a meticulous look at surgical research and the process of introducing medical devices to the US market provides compelling evidence why RCT may have limited utility in this arena. As elegantly stated by McCulloch et al., operations are complex procedures.[8] Quality and results are affected by many factors, including but not limited to learning curve, variations in technique, blinding and quality control.

The concept of the learning curve was first introduced in behavioral psychology, and subsequently applied in the aircraft industry. A learning curve describes the increase in learning coincident with experience or repetition. In surgery, every new surgical technique, instrumentation or modification to an existing technique has a learning curve. Unlike drug trials, this is a unique variable in surgical RCT, especially minimally invasive surgery, and is difficult to control between treatment arms.[9] During the learning curve, errors and adverse outcomes are more likely, regardless of pre-clinical training. During that learning curve, modifications, and variations of a technique or operation with a novel instrument has the potential to influence surgical outcomes and success. Solutions for the above problems unique to surgical RCT include the use of appropriate statistical techniques, and performance of surgical phase 2 trials prior to RCT in order to elucidate learning curve analysis of participating surgeons, suitable end-points for subsequent RCT and quality issues, among others.

The reasons for the lack of RCT in surgical research are far more complex, and perhaps out of the scope of this review. However, it is important to mention the lack of funding for surgical research, and the role of government in such endeavors. The United States Congress in 1997 amended the US Food and Drug Administration (FDA) Act on medical devices and radiation-emitting products in an effort to streamline the process of bringing safe and effective drugs, medical devices, and other therapies to the US market. Paradoxically, the current process is gradual and relies heavily presumably on expert committee members calling into question the weight of evidence versus expert opinion in the approval process.

A closer look at this process reveals a lack of transparency and a complex method that is daunting for any surgeon-investigator in this field of research. Offices of medical product regulation within the FDA are further divided into the Center for Biologics Evaluation and Research (CBER), the Center for Drug Evaluation and Research (CDER), and the Center for Devices and Radiological Health (CDRH). In contrast, in Europe, to legally place a medical device on the European market, medical devices must meet the ‘Medical Device Directives’, and devices or products conforming with such directives can obtain a ‘CE mark’. Clearly in the European Union the process is simplified providing physician-scientists an edge on medical/surgical devices research. Of note, an FDA or CE mark-approved medical device rarely requires RCT; moreover, it is not a ‘safety mark’ rather it means compliance with government regulatory process by the industry prior to market. Albeit a complex process, it is intended to verify that the device complies with safety, health, and environmental protection requirements: a process not suitable for RCT.

Obese Patients and those with Endometrial Cancer may Benefit from Robotic Surgery

  1. Top of page
  2. Abstract
  3. Obese Patients and those with Endometrial Cancer may Benefit from Robotic Surgery
  4. Conclusions
  5. Disclosure
  6. References

The identification of subgroups of gynecologic patients that may benefit from robotic surgery has been complicated by the lack of RCT. Nonetheless, retrospective studies suggest that obese patient and those with endometrial and cervical cancers may benefit from robotic surgery. These hypotheses are worthy of prospective evaluation.

Results from the LAP-2 study, a randomized controlled trial comparing laparoscopic staging of endometrial cancer to open staging, demonstrated a positive association between BMI and the likelihood of conversion to laparotomy among patients randomized to laparoscopy.[10] The conversion rate among patients with a BMI < 25 kg/m2 was 17.5% steadily increasing to 57.1% among patients with BMI > 40 kg/m2 (P < 0.0001).

Given the enhanced visualization, dexterity and ergonomics of robotic surgery, it is proposed that this approach may be of benefit to obese patients – providing a path to minimally invasive surgery where laparotomy would be required, either primarily or due to conversion from laparoscopy. A review of 181 endometrial-cancer-staging cases (105 robotic and 76 laparoscopic) demonstrated a lower conversion rate (12% vs 26%, P < 0.001) among the robotic cohort despite a higher mean BMI (34 kg/m2) compared to the laparoscopic cohort (29 kg/m2).[11]

Robotic surgery may facilitate the successful completion of staging lymphadenectomy for endometrial cancer. A retrospective review of 2464 staging procedures (1027 laparoscopic and 1437 robotic) demonstrated that patients undergoing robotic surgery were more likely to complete staging, including lymphadenectomy, compared to the laparoscopic cohort (77% vs 23%, P < 0.001).[1] Neither tumor stage nor histologic data were available, thus it is unclear whether unequal distribution regarding these variables contributed to the observation.

Advantages of robotic radical hysterectomy in the management of cervical cancer are less forthcoming. Estape et al. reported higher lymph node counts among 32 patients undergoing robotic surgery compared to 17 patients undergoing laparoscopic surgery.[12] Magrina et al. reported equivalent lymph node counts among patients undergoing robotic versus laparoscopic surgery.[13] Obermair et al. proposed a prospective randomized equivalence trial comparing robotic versus laparoscopic radical hysterectomy among patients with Stage IA1–IB1 cervical cancer followed by adjuvant therapy based upon standard risk factors.[14] A total of 370 patients are required in each arm to demonstrate that disease-free survival among patients randomized to robotic surgery is no more than 7% different compared to the control arm with 80% power and a two-sided alpha set at 0.05. To date, this trial has not yet met its recruitment goals.

Robotic surgery and physician training

The rapid growth of robotic surgery in gynecology has raised the concern that its appeal among providers may threaten the teaching of laparoscopy to residents. This concern would be particularly valid if the growth of robotic volume in gynecology is at the expense of laparoscopic cases. Hoekstra et al. reported the impact of adding robotic surgery to their gynecologic oncology program in 2007.[15] Prior to the debut of robotics, only 3.3% of patients undergoing staging for endometrial cancer and radical hysterectomy for cervical cancer underwent a minimally invasive procedure. A year after the introduction of robotics, the proportion of laparoscopic cases grew to 11% and robotic cases to 49%. The proportion of cases performed via laparotomy decreased from 94% to 49%.

Knight et al. reported the experience of the gynecologic oncology division after introduction of robotic surgery in 2006.[16] This division, unlike that reported by Hoekstra et al., had an established laparoscopy program with 13.5% of patients undergoing minimally invasive surgery prior to robotics. The introduction of robotics did not compromise laparoscopic volume. To the contrary, the proportion of cases performed laparoscopically increased to 31.5% in the 6 years after the introduction of robotics. During the same interval, robotic volume increased to 10% and open volume decreased to 58.5%, P < 0.001.

In contrast to the experience in oncology, the impact of robotics on proportional volume of laparoscopic hysterectomy for benign indications has not been positive. Brenot et al. reported a decrease in the proportion of laparoscopic hysterectomies in the year after the debut of robotics at their institution (21% to 8%, P < 0.001).[17] Similarly, Wright et al. reported that at hospitals where laparoscopy programs existed, the introduction of robotics resulted in a small decrease in the proportion of hysterectomies performed laparoscopically (28.9% to 24.5%).[1]

The impact of robotics on resident training has been queried using surveys. Among surveyed residency program directors, 76% reported that robotics was being performed at their institution; 28.6% of directors reported confidence that graduating residents were completely prepared to perform laparoscopic hysterectomy; and 17.7% of directors reported that residents sat at the console often. None of the directors were confident that graduating residents were prepared to perform robotic hysterectomy. Among responding directors, 71.5% believed the introduction of robotics is having a negative impact on the resident training nationally. The response rate of queried directors was 50%.[18]

Smith et al. surveyed residents regarding their exposure to robotic training.[19] Among senior residents, 29% reported operating at the console and only 3.6% of residents reported confidence in their ability to perform robotic surgery without additional training; 79% reported that formal training is necessary in robotics, but only 38% reported receiving such training. Although 470 residents completed the survey, the response rate was not reported. To date, surveys querying resident training in robotics have not reported the proportion of programs with fellowship and whether residents feel the presence of fellows impacts their surgical training.

While survey data raise concerns regarding the impact of robotics on the quality of resident education, what is unknown is whether perceived shortcomings in training translates into tangible deficits in clinical practice. Most would likely agree that skill building continues after residency and thus one's training is not complete upon completion of residency. Nonetheless, core proficiencies are required for safe surgical practice. The lack of confidence among both residency program directors and residents in graduates' skill sets raises the concern that enhanced curricula addressing perceived areas of weakness are required along with metrics to assess proficiency at core robotic and laparoscopic competencies. Notably, it conveys to all of us involved in education and training the weakness of Obstetrics and Gynecology as a surgical specialty and perhaps a call to change the core of the specialty as to how we train and educate ‘reproductive surgeons’.

The impact of willingness-to-pay and competition on robotic surgery

Being the newest major advance in surgical technology it is not surprising that robotic surgery is the most expensive approach. Like any new technology, however, the premium charged for this technology is not guaranteed. The cost of robotics, like any other free market commodity, is subject to pressure from customers' willingness-to-pay and the presence of competitors. Currently, robotic hysterectomy is 32% more expensive than laparoscopic hysterectomy, including amortized fixed costs associated with robotic surgery.[1] Either a decrease in customers' willingness-to-pay or the entry of a competitor would place downward pressure on cost such that robotic hysterectomy may become cost equivalent, or perhaps less expensive than laparoscopy. While it is difficult to estimate the effect size of decreased willingness-to-pay or competition on the price of robotics, we can draw some understanding of these forces by reviewing price trends of other medical equipment. When first introduced, manufacturers of cardiac pacemaker devices demanded premium prices. Over time, competition and willingness-to-pay contributed to price reduction. Decreased Medicare reimbursement schedules and increased competition contributed to a 43% decrease in the price of pacemakers over a 12-month period.[20]

Entry of a competitor would introduce significant downward pressure on price. The effect size of competition would likely be substantial because a competitor would need to price its product substantially lower to entice physicians and hospitals to abandon current technology in which large investment in equipment and training has been made. Admittedly, this represents a high barrier to entry evidenced by the absence of a competitor in the 10-year monopoly of the current robotic surgery manufacturer. In the absence of competition, decreased willingness-to-pay in response to reports suggesting no added clinical benefit to robotic hysterectomy may cause prices to fall.

The impact of willingness-to-pay on the price can be large, especially when added clinical benefit cannot be proven by RCT. In the wake of a large cancer center refusing to purchase a new chemotherapeutic agent because it cost twice as much as an older drug with the same efficacy, the manufacturer responded with a 50% price reduction, making the new drug equal in price to the old drug.[21] While the effect size of willingness-to-pay on the price of robotics cannot be determined, it is likely that the prices will fall if the lack of proven clinical benefit gains traction with payors who will limit reimbursements and hospitals that will limit investment.

On the other hand, perhaps added clinical benefit has not been demonstrated because no proper RCT have been conducted. In the USA, hysterectomy is the most common gynecologic surgical procedure performed with approximately 600 000 cases per year, accounting for over 5bn health-care dollars.[22] Analysis of surgical data for 2003, demonstrated that abdominal hysterectomy was performed in 66% of cases, vaginal hysterectomy in 22% of cases, and laparoscopic hysterectomy in 12% of cases.[23] It is evident by now that after years of training, continued medical education, courses in laparoscopy, modifications in resident education-training and hundreds of thousands of dollars in annual meeting courses, the diffusion and adoption of laparoscopic hysterectomy remains poor at best in the USA when compared to other commonly performed procedures, such as cholecystectomies.[24] Hence, payors and health policy makers in the USA may adopt a high-cost surgical modality because of the ability to provide surgeons with a reproducible platform to offer patients a minimally invasive approach to hysterectomies.

The interaction of economics and the delivery of care is a global phenomenon. For instance, in Canada health care is delivered through a publicly funded health care system, which is mostly free at the point of use and has most services provided by private entities.[25] In this public health care environment, Lau et al. demonstrated in a prospective non-randomized fashion that robotics for endometrial cancer surgery increased the proportion of patients benefitting from minimally invasive surgery, improved short-term outcomes, and resulted in lower hospital costs.[26] Therefore, contingent on different socioeconomic environments, challenges, cost and tensions among those paying for the care, those providing the care, and those marketing the devices can be different (Fig. 1).


Figure 1. Factors related to cost in robotic surgery.

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  1. Top of page
  2. Abstract
  3. Obese Patients and those with Endometrial Cancer may Benefit from Robotic Surgery
  4. Conclusions
  5. Disclosure
  6. References

Studies reporting that robotics is less cost-effective compared to laparoscopy rely on retrospective studies. These retrospective studies, while unable to show added benefit of robotics compared to laparoscopy, are prone to treatment bias by providers. The statistical methods used to control for this bias complicate the examination of the data to determine whether there exist subsets of patients for whom robotics present benefit compared to laparoscopy. RCT control for treatment bias via randomization. They also allow powered sub-group analysis. Despite being the gold standard in medical science, RCT may have limited utility in evaluating surgical techniques or instrumentation because of the unique challenges to the surgical sciences, and funding for such research.

With data demonstrating that either vaginal or laparoscopic hysterectomy is more cost-effective than laparotomy, neither approach is utilized as frequently as laparotomy, which remains the most common approach to hysterectomy in the USA. Robotics may provide a more easily accepted pathway for providers to offer minimally invasive surgery. Compared to laparotomy, robotic hysterectomy is cost-effective. Thus, the fair comparison may not be between robotics and laparoscopy, but between robotics and laparotomy. There is concern that robotics hinders the training of laparoscopy and other minimally invasive modalities. The data reported so far for gynecologic oncology suggest that the introduction of robotics has not reduced such volume. Among benign divisions, adoption of robotics decreased laparoscopic volume, but the decrease in open volume was much greater.

We should embrace technologies that provide a safe minimally invasive alternative to laparotomy. Special attention should be given to those technologies that are less expensive than laparotomy and have a short enough learning curve and high reproducibility that they may be adopted by a large number of gynecologic surgeons. As we move forward into an environment that is increasingly cost conscious and complex, the interactions of economics, novel medical technology and global delivery of health care will be of paramount importance.


  1. Top of page
  2. Abstract
  3. Obese Patients and those with Endometrial Cancer may Benefit from Robotic Surgery
  4. Conclusions
  5. Disclosure
  6. References

Pedro F. Escobar, MD: Consultant for Intuitive Surgical.

Jason Knight, MD: No conflict of interest.


  1. Top of page
  2. Abstract
  3. Obese Patients and those with Endometrial Cancer may Benefit from Robotic Surgery
  4. Conclusions
  5. Disclosure
  6. References
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    Whiteman MK, Hillis SD, Jamieson DJ et al. Inpatient hysterectomy surveillance in the United States, 2000–2004. Am J Obstet Gynecol 2008; 198: 34.e1347.
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