Abstract
The declining birth rate and aging population are becoming increasingly serious social issues in Japan. In this report, we summarize the current congenital heart surgery and pediatric perfusion practices in Japan and Vietnam. In addition we report the rapid growth and development of congenital heart surgery in Vietnam made possible by medical education support provided by Japan over the past decade.
Keywords
Current Status of Pediatric Cardiac Surgery in Japan
There are 1,516 cardiovascular centers in Japan including approximately 150 congenital heart centers, 1 with an estimated 8,700 congenital heart surgery procedures performed each year. 2 This number of congenital heart surgery operations has remained stable for 20 years, except in 2022, during the COVID-19 pandemic. Approximately 60% of the congenital heart surgery centers in Japan perform less than 50 procedures annually. 3 This is a typical situation in the Japanese medical system, which contains many small-scale facilities. This is different from other countries where most centers generally perform more than 100 operations annually. When determining the relationship between the number of operations performed at a facility and the severity of the cardiac anomaly for which the patients are being treated, large-scale facilities generally manage a higher number of high-risk procedures. 3 Moreover, the observed to expected ratio for 90-day mortality is determined by the number of annual operations. In Japan this ratio is 1.37 for facilities with fewer than 50 cases per year and 0.78 for facilities with over 150 cases per year. 3 These figures show that in some instances the actual surgical and perfusion experience is not optimal. To overcome this, virtual reality (VR) training or other simulation-based training could be implemented to supplement the number of actual surgical cases. To address this situation where the number of congenital heart disease cases per facility is on the low side, it would be necessary to consolidate congenital heart surgery facilities in Japan. Regarding mechanical circulatory support in Japan, approximately 29,000 circulatory support systems have been utilized including approximately 20,000 intra-aortic balloon pumps (IABP), 8,700 cardiac extracorporeal membrane oxygenation (ECMO) devices, and 300 left ventricular-assisted devices (LVADs).2-4 Since the Organ Transplantation Act was passed in October 1997, 625 heart transplantations (HTx) have been performed in Japan as of December 2021. Of these, 556 HTx procedures were performed after activating the revised Transplant Act, while 84 were performed in 2019. In 2021, this number fell to 56 owing to the COVID-19 pandemic. 4 Only 66 donors under 18 years of age have been used since the law was amended in 2011. 4
Current Status of Pediatric Mechanical Circulatory Support and Pediatric Perfusion in Japan
During the COVID-19 pandemic from February 2, 2022 to March 31, 2023, 1,403 ECMO support devices were in operation. The survival rate of patients was 63.2%. 5 The difficulty of providing long-term support as a bridge to HTx prompted the introduction of VADs for children in Europe and the USA. Several pediatric implantable VADs are currently under development in Japan, as well as in Europe and the USA. Pediatric VADs for congenital heart disease with complex cardiac anomalies require adaptation to various anatomic conditions. An analysis of the long-term results of the Berlin Heart EXCOR for pediatric patients between 2012 and 2019 in Japan showed that of the 45 cases (mean age, 2 years 4 months; average assisted duration, 363 days), HTx was completed in 16 cases, the patients were weaned off the VAD in 12 cases, 14 cases were still ongoing, and 3 cases were lost to follow-up. 6 Prompt deployment of these devices is necessary to facilitate successful outcomes for children with advanced heart failure.
Current Pediatric Perfusion Practices at the E Hospital in Hanoi, Vietnam
We want to highlight the excellent relationship between the “E hospital” in Hanoi, Vietnam and surgeons from Japan, facilitated by the educational support under the direction of Professor Shunji Sano since 2007. The E hospital has 1,100 beds. As of 2023, centers in Vietnam have conducted 1,535 heart surgery procedures. Of these operations, 1,112 pump cases included 528 complex congenital heart surgery procedures using cardiopulmonary bypass (CPB). The cardiovascular surgery techniques at the E hospital have been improving steadily year by year, and they are currently able to perform complex congenital heart procedures, which was not possible 10 years ago. Two perfusionists are assigned to each pediatric perfusion procedure to ensure safe management, just as in Japan. Minimally invasive cardiac surgery with vacuum-assisted venous drainage is challenging. Each perfusionist at the E hospital performs 200 cases per year. However, they do not have much experience with mechanical circulatory support such as ECMO and VADs, because of medical insurance issues. Fortunately the number of mechanical circulatory support procedures has been increasing due to the economic development in Vietnam over the past several years.
Summary
We report the current status of pediatric cardiovascular surgery and cardiopulmonary bypass in Japan and Vietnam. Japan has shown an accelerated population decline since 2008; conversely, Vietnam's population is rapidly increasing, and is predicted to exceed that of Japan by 2035. The number of operations for congenital heart disease in Japan is expected to decrease due to the population decline and declining birthrate. As a result, the number of operations for congenital heart disease itself will decrease, in turn causing a decrease in the number of actual clinical experiences of surgeons and perfusionists who perform these operations. This may result in a lack of sufficient training to improve surgical techniques. Of course, surgical training methods could be supplemented with new VR simulation training, but these are not comparable to actual clinical experience. Although this may not be an ideal situation, to maintain the efficiency of congenital cardiovascular surgery in Japan, we are currently consolidating facilities, while ensuring that each facility has sufficient surgical experience. In contrast, in Vietnam, characterized by economic development and a population increase, the number of congenital heart operations is expected to increase, and technological innovations are expected to continue. Improvements in treatment technology for complex congenital heart disease and patient management environment, including postoperative management, will improve treatment results. When envisioning the future, Japan would like to continue to provide medical technology education support to developing countries such as Vietnam. We hope that the medical technology for congenital heart disease surgery that Japan has developed over the past many years will be of use to all children with congenital heart disease worldwide in the future.
Footnotes
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
