Technical Considerations for Reducing The Cost of Robotic Lobectomy for Lung Cancer

The cost of robotic assisted surgery is an obstacle to wider implementation. We aimed to evaluate the effect of our strategy to reduce the cost of robotic lobectomy (RL) for lung cancer. This single institutional retrospective study included RL for lung cancer between October 2018 to November 2019. We initiated minimal RL (miRL) in September 2019 aiming to reduce the consumable cost, in which we intended to use only bipolar fenestrated (left), long bipolar grasper (right) and vessel sealer (3rd arm) as robotic instrument. Additional consumable cost was calculated based on Japanese catalog price (1USD = 110JPY) to perform RL (excluding robot and maintenance fee, and staplers) compared to our video assisted thoracoscopic surgery lobectomy (VATS-L) (3 ports, no energy device). We then assessed the effect of miRL on the cost and perioperative outcomes.


Results
In all cases with miRL, procedure was completed with only 3 arms. The mean (range) additional consumable cost to perform RL compared to VATS-L was signi cantly reduced in the miRL group

Conclusions
With miRL strategy in our cohort, consumable cost for RATS-L was signi cantly reduced while maintaining perioperative outcomes. Further evaluation with larger number of patients is warranted.

Introduction:
The cost of robotic surgery is an obstacle to wider implementation. We evaluated the cost-effectiveness of our institutional strategy to reduce the consumable cost of robotic lobectomy (RL) for early-stage lung cancers.

Methods:
This study was approved by the institutional review board (Ashikaga: No 2019-43) on February 5, 2020 and consent was waived. This single institutional retrospective study included consecutive cases of RL for lung cancer completed between October 2018 and November 2019 (Ashikaga). All procedures, including a systematic lymph node dissection, were performed by a single operator (KH) with da Vinci Xi surgical system (Intuitive Surgical, Sunnyvale, CA, USA), using all 4 arms. To reduce consumable cost, we initiated a minimal RL (miRL) strategy in September 2019 attempting to use only three robotic instruments (other than robotic staplers): bipolar fenestrated (left arm), long bipolar grasper (right arm), and vessel sealer (third arm) unless otherwise required (Fig. 1, Online Resource 1). Before this strategy was implemented, we used any robotic instruments necessary to mimic our existing video-assisted thoracoscopic lobectomy (VATS-L) technique. We also omitted carbon dioxide insu ation (AIRSEAL was otherwise used) in this strategy. Additional consumable cost was calculated based on a Japanese catalog price (1 USD = 110 JPY) for performing RL (excluding robot itself, its maintenance fee, and staplers), in addition to our VATS-L (3 ports, no energy device) instrument set. We then assessed the cost and perioperative outcomes of miRL.
A comparison was performed using the non-parametric t-test for continuous values, and the Fisher's exact test for categorical values. All p-values were two-sided, and < 0.05 were considered statistically signi cant.

Results:
Twenty-one RL were performed. There were no cases with concomitant vascular/bronchial reconstruction procedures. There were no signi cant differences in patient characteristics between the miRL group (N = 6) and the control group (N = 15) ( Table 1: Characteristics). There were no cases with concomitant resection of the surrounding structures or vascular/bronchial reconstruction procedures. The intraoperative and short-term outcomes are summarized in Table 1

Discussion:
The robotic platform has several potential advantages over VATS including better dexterity, improved visualization, and faster learning curves. The maneuverability of robotic platform may also help perform complex lobectomy, such as sleeve resection, in a minimally invasive approach [1]. However, it is still debatable whether RL is cost-effective compared to VATS-L for early-stage lung cancers [2][3][4][5]. In many health systems, its cost poses a signi cant challenge in wider implementation.
There were some technical tips for using each preset robotic instrument in our strategy. First, the long bipolar dissector in the right arm can be used to dissect, grasp, coagulate, hold needles, and encircle relatively large veins. Before this strategy, we used a monopolar device or a short Maryland forceps for dissection and switched to the Cadiere forceps for encircling vessels or tying knots. The long bipolar dissector also replaced the needle driver. Second, the vessel sealer in the third arm can not only seal the small vessels but also grasp a sponge or the lung for retraction and cut the sutures. This has replaced the clipping device, tip-up grasper, and scissors. Finally, avoidance of insu ation with CO2 did not pose signi cant challenge to our exposure.
There are limitations in this study. First, this is a retrospective study with a small sample size. Second, the absolute price cannot be generalized as each health system has different calculation methods. Nevertheless, as this reduction is directly related to signi cantly reduced consumable resources, the strategy would be bene cial in many health systems.

Conclusion:
With minimal RL strategy in our cohort, consumable cost for RL was signi cantly reduced while maintaining perioperative outcomes. Further evaluation with larger number of patients is warranted.

Declarations
Con icts of interest statement: Authors have nothing to declare.

Funding information:
This research received no speci c grant from any funding agency in the public, commercial, or not-forpro t sectors.
Ethics approval and consent to participate: This study was approved by the institutional review board (Ethical review board at the Japanese Red Cross Ashikaga Hospital: No 2019-43) on February 5, 2020 and consent was waived. All methods were carried out in accordance with relevant guidelines and regulations.
Consent for publication: Not applicable.
Availability of data and materials: Data is available for review and the corresponding author should be contacted if necessary.
Authors' contributions: K.H. wrote the main manuscript text. All authors contributed to performing surgery, data acquisition and reviewed the manuscript.