Advances in minimally invasive liver surgery: comparing robotic and laparoscopic approaches

Liver resection has traditionally been performed using an open approach, but many academic tertiary centers have adopted a minimally invasive surgical (MIS) approach to liver surgery over the past two decades. Laparoscopic liver resection (LLR) remains the most common MIS approach to liver surgery worldwide. However, there has been recent increased adoption of robotic liver resection (RLR).

The assumptions made in studying MIS liver surgery, according to the International Consortium on Minimally Invasive Liver Surgery (I-MILS) (1), are similar to those for other forms of MIS surgery. There are certain advantages, such as decreased pain, reduced length of stay (LOS), and lower wound infection rates. However, beyond these benefits, the slow adoption of MIS hepatectomies is due to concerns about using MIS approaches for hemorrhage control, achieving adequate R0 surgical resection of malignancies, and the inevitable learning curve associated with performing such complex surgeries. While no fewer than 36 manuscripts have compared open hepatectomy to RLR and LLR, as shown in a recent systematic review (2), there is little debate about the advantages of RLR over open hepatectomy. It is still unclear whether RLR offers any advantages over LLR, as many studies have not matured yet. Some assumptions made include that robotics provide increased dexterity with a greater range of motion and an easier learning curve compared to LLR. This propensity-matched, multi-center analysis by Sijberden et al. aims to highlight some potential advantages of RLR over LLR.

With 10,075 patients, this study covers not only the initial adoption of robotics in the late 2000s but also a subgroup analysis of MIS hepatectomies performed after 2015, to highlight differences after a certain learning curve had been reached. Some of the key criteria for hepatobiliary surgeons when offering MIS hepatectomy operations to patients include the patient’s risk factors, such as cirrhosis, extensive prior abdominal surgeries, underlying cardiac comorbidities precluding pneumoperitoneum, and the extent of resection required. In addition, surgeons rely on their experience with open hepatectomies to assess potential intraoperative complications when using MIS approaches. These differences, highlighted in this study by operative complexity (anterolateral, posterosuperior, and major hepatectomy), represent the largest cohort to date. This adds significant power to compare RLR versus LLR across demographic comorbidities, malignant versus benign pathologies, and perioperative complications such as bile leaks and post-hepatectomy liver failure. Other metrics measurable by the surgeon and hospital system include operative cost analysis [not covered in this article (3)], LOS, and readmission rates.

This study highlights decreased use of the Pringle maneuver with RLR (39.6% vs. 49.7%, P<0.001), increased R0 resection with RLR (89.8% vs. 84.7%, P<0.015), decreased operative time {190 [95% confidence interval (CI): 136–270] vs. 210 (95% CI: 134.3–299.5), P<0.023}, and improved textbook outcomes after liver surgery (TOLS) (4), which presumably reflect decreased intraoperative bleeding and fewer postoperative grade B and C bile leaks. In contrast, the RLR approach had a higher 30-day readmission rate in the cohort after the learning curve (post-2015) (6.5% vs. 4.9%, P<0.001).

Previous multi-institutional studies comparing major RLR versus LLR resections have shown a decreased conversion rate (5,6) to open surgery with RLR. However, Montalti et al. also highlighted that those converted from RLR to open surgery had worse complications and outcomes compared to LLR conversions (6). While Sijberden et al. also showed a decreased conversion rate (RLR 2.7% vs. LLR 8.8%, P<0.001), the outcomes of those who required conversion were less clear. Reasons for conversions with MIS liver surgery are well-highlighted by a multi-center registry known as AMILES (major resection, cirrhosis, prior liver surgery, and tumor proximity to major vessels, P<0.05) (7). However, if no conversion was needed, similar outcomes were observed compared to prior studies, showing reduced transfusion rates, reduced estimated blood loss (EBL), similar postoperative LOS, and similar overall morbidity and 90-day mortality rates.

Some studies fall short when describing the complexity of MIS liver resection as they are single-institution, single-surgeon (8), case series or of lower overall quality. This article, however, is international, involving a diverse group of tertiary centers, and does a great job highlighting its inclusion/exclusion criteria. It is risk-stratified by performing propensity matching by type of MIS liver resection, subgroups by era, and underlining the data limitations. These limitations include the retrospective study design, potential selection bias early and late in the robotic era, and the use of CUSA (Cavitron Ultrasonic Surgical Aspirator) in five centers as a hybrid approach (laparoscopic CUSA with RLR). We know that dissection in cirrhotic and fatty livers, without injuring major vessels, is one of the hallmarks of CUSA. However, without a robotic CUSA to dissect in an RLR, there is potential for confounding outcomes in a minor subset of this cohort.

Cost analysis was not the focus of this article but should be emphasized. Operating robotic rooms may be more expensive, and availability may be an issue in some resource-limited centers. Cost has been addressed previously, showing that high-volume centers have an increased cost per bundled hospital stay (3). In that same analysis by Sahara et al., the likelihood of complications and death within 90 days was lowest among high-volume surgeons (3). This finding is logical but challenges us to assess the cost-effectiveness of offering RLR to those with minor wedge resections or posterosuperior resections, which can lead to selection bias. However, if we are to achieve standardization for expected outcomes in minor and major MIS hepatectomies using the robot, we can use this selection bias to our advantage. The now well-established Comprehensive Complication Index (CCI) (9) can be used to provide standards in the evolving use of RLR. However, there was not enough granularity in this study to calculate this index.

In conclusion, this article is the largest study to compare RLR to LLR and shows that RLR is here to stay. What we need to know now is how to select the right patients for each type of operation and measure our outcomes with a standardized best practice model that is globally generalizable. Future prospective randomized studies at high-volume centers will be needed to fully appreciate the benefits of RLR.

Acknowledgments

Funding: None.

Footnote

Provenance and Peer Review: This article was commissioned by the editorial office, HepatoBiliary Surgery and Nutrition. The article did not undergo external peer review.

Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at https://hbsn.amegroups.com/article/view/10.21037/hbsn-2024-678/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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