Impact of robot-assisted surgery appearance on reduction of annual blood transfusion cases in Japan: application of meta-analysis and NDB open data.

In Japan, the robot-assisted partial nephrectomy (RAPN) started to be covered by health insurance since 2016, and it is replacing conventional open partial nephrectomy (OPN). RAPN is a minimally invasive surgery, and the spreading of RAPN in partial nephrectomy (PN) performed annually is expected to reduce the number of blood transfusions in Japan. The number of PN surgery in Japan was calculated using the Japanese NDB open data in 2018. We extracted articles comparing the transfusion rates of RAPN and OPN from 2017 to 2021 using PubMed, Web of Science, and Ichu-shi, and integrated the ratios of transfusion rates by meta-analysis. We estimated the reduction in the annual transfusion cases in PN due to the widespread use of RAPN. The total number of renal cancer surgeries in 2018 was 21,298, of which 3,876 (18.2%) were RAPN and 4,384 (20.6%) were OPN. For the comparison of transfusion implementation rate between RAPN and OPN, 871 articles were screened and 27 articles were included. The pooled ratio in transfusion rate of RAPN compared with OPN was 0.49 [0.46, 0.52]; the introduction of RAPN was estimated to have reduced the annual number of transfusions in PN by 9.1% compared with that of unintroduced RAPN. This study showed quantitatively evaluated the impact of the introduction of RAPN on the decrease in the annual number of transfusions in Japan. This method has the potential to evaluate the impact of robot-assisted surgery on the use of blood products for transfusion.