Health Services Research & Development

09/18/2020 | Press release | Distributed by Public on 09/18/2020 10:28

Robot-assisted Procedures in General Surgery: Cholecystectomy, Inguinal and Ventral Hernia Repairs

The report is a product of the VA/HSR&D Evidence Synthesis Program.

Robot-assisted Procedures in General Surgery: Cholecystectomy, Inguinal and Ventral Hernia Repairs

General surgery procedures make up a large volume of operations performed in the US. For example, there are approximately 1 million cholecystectomies and 800,000 ventral and inguinal hernia cases performed each year. Within this field, there has been dramatic recent growth in the number of robot-assisted cases. Questions about the utility of robot-assisted surgery as compared to laparoscopic and open surgery persist. In particular, does the use of the robot-assisted approach translate to better or similar clinical outcomes for patients? Are operating room times and length-of-stay comparable or improved with the use of robot-assisted versus laparoscopic or open techniques? And what are the costs of robot-assisted surgery, and are they justified? Yet, there is no consensus or guidelines on when to use which surgical approach and decisions are left up to individual practitioners or hospital leadership.

A cholecystectomy is a surgical procedure to remove an individual's gallbladder. A hernia is a defect in the fascial tissue (mainly abdomen or groin); this can lead to symptoms or complications if organs or tissues (i.e., intestine) protrude through this defect. An inguinal hernia occurs in the groin area. A ventral hernia occurs in the abdomen wall and can be congenital or acquired (i.e., after an operation).

This systematic review sought to help clinicians, patients, and policymakers better assess the appropriateness of robot-assisted compared to other surgical approaches by assessing the literature on three common general surgery operations: cholecystectomy, inguinal hernia repair, and incisional hernia repair. Investigators with VA's Evidence Synthesis Program (ESP) Center in West Los Angeles, CA searched the literature, including PubMed, Embase, and Cochrane (all databases) from 2010 to March 2020. For inguinal and ventral hernia repairs, Medline also was searched from 2010 to 2020. For cholecystectomy, they identified 887 potentially relevant citations and 47 met inclusion criteria. For inguinal hernia repair, 3,319 potentially relevant citations were identified, and 9 publications were recommended by experts; of these, 23 publications met review inclusion criteria. For ventral hernia repair, 3,458 potentially relevant citations were identified, and 5 publications were recommended by experts; of these, 22 met inclusion criteria.

Summary of Findings

Overall, the studies were heterogeneous in terms of patient characteristics and how the operations were performed, thus strong conclusions cannot be made. That being said, where possible, investigators compared study arms in which important technical variations were accounted for. For example, within cholecystectomy studies, they assessed outcomes by factoring in the number of ports used in the comparison arms (single-port to single-port; multi-port to multi-port).

Operating Room Time

Robot-assisted surgery for cholecystectomy, inguinal hernia repair, and ventral hernia repair is associated with longer OR times, in general, and the strength-of-evidence ranged from high to low, depending on the procedure.

Post-operative Length of Hospital Stay

Most studies did not demonstrate a significant difference in length of stay (LOS). This was consistent among studies except in those comparing single-port robot-assisted cholecystectomy to single-port laparoscopic approach which showed a decrease in length of stay for the robot cohort.

Post-operative Complications

For inguinal and ventral hernia repairs, some post-operative complications may be lower with the robot-assisted approach as compared to open. There is evidence that a number of post-operative events are lower for ventral hernia repair - specifically, post-operative complications and surgical site infections (as compared to open approach) - but these both had low certainty of evidence. In general, the certainty of evidence is low or very low, as there were few randomized controlled studies to support the conclusions of the findings from the observational studies.

Rates of Hospital Readmissions

Overall, readmission rates are lower for robot-assisted cholecystectomy, but with low certainty of evidence.

Long-term Outcomes

Regarding long-term outcomes, such as recurrences or chronic pain (for the two types of hernia repairs), data are too sparse and imprecise to reach any conclusions. Overall, the comparator arms for these procedures were limited by differences in patient factors, hernia factors (i.e., laterality, hernia size), and varying techniques (i.e., type of fascial closure).


Cost studies found higher expense associated with robot-assisted surgery, which was consistently reported, but these are limited by the wide variability in the methodologies and definitions used to measure cost. Formal cost-effectiveness for these three procedures has not been estimated and definitive conclusions regarding the balance between benefits, risks, and cost cannot be made. If efficiencies in the robot-assisted approach improve over time (as the learning curve is achieved), this, in turn, may bring down some of the costs. Investigators are not aware of any robot-assisted cost data within VA, but utilization data are available and may serve as a first step towards future research in this area.

Implications for VA

There were a limited number of studies specific to VA patient populations: one was on cholecystectomy, one was on inguinal hernia repair, and there were none on ventral hernia repair. As such, investigators were unable to make specific conclusions from VA data.

Applicability of results from non-VA patients to VA patient populations may depend on both the similarity of the patients studied to VA patients and the experience of the surgical teams using robot-assisted surgery to VA surgical team experience. However, the benefits for a robot-assisted approach still may be realized despite patient-level differences, as VA's patient population has a greater burden of comorbidities than the general public, but this needs to be confirmed in future studies. Urologic surgery has been widely adopted in VA, so this experience for staff may translate into an easy implementation to the robot-assisted general surgery field.

Research Gaps/Future Research

Numerous research gaps are apparent. There is a need for randomized data or propensity matched data that addresses patient- and technique-related factors. The variability in the use of the robot-assisted approach based on these factors limits the ability to compare across study arms, as variations at baseline or differences in how the operation was performed are large and may likely be responsible for clinical differences or lack thereof. However, there are clear advantages of the robot-assisted approach not addressed in this review, such as enhanced visualization, augmented dexterity and range-of-motion, and reduction of tremor, to name a few. The heterogeneous nature of the studies limited the ability to show how these features may translate into better clinical outcomes. Studies that control for key patient factors, case complexity, technical aspects of procedures, and surgeon experience may provide insight into this overarching question. Adequate long-term follow-up for certain outcomes is needed. In addition, areas that warrant specific discussion include but are not limited to surgical learning curve, resident training, and future innovation in surgical robotics.

Maggard-Gibbons M, Girgis M, Ye L, Shenoy R, Mederos M, Childers CP, Tang A, Mak SS, Begashaw M, Booth MS, Wilson M, Gunnar W, Shekelle PG, Robot-Assisted Procedures in General Surgery: Cholecystectomy, Inguinal and Ventral Hernia Repairs. Los Angeles: Evidence Synthesis Program, Health Services Research and Development Service, Office of Research and Development, Department of Veterans Affairs. VA ESP Project #05-226; 2020.

To view the full report, go to (intranet only, copy and paste link into your browser)