Kidney Transplantation: Innovations in Research and Treatment

Editorial

This methods collection summarizes new findings on the topic of kidney transplantation both in research and in treatment. Important progress has been made on this topic in recent years, leading to improvements in therapeutic measures with reduced acute rejections and improved graft and patient survival rates. In addition, improvements have been made in the field of kidney transplantation from living donors and in extending kidney transplantation to HLA- or ABO-incompatible couples or to elderly patients. Further progress has been made with the utilization of kidneys from so-called marginal donors, including non-heart-beating donors at the time of donation. This progress is illustrated by the persistence of kidney transplantation even during the COVID-19 pandemic.

Overall, five articles were collected^1,2,3,4,5, and each describes different aspects of kidney transplantation. Two of the articles describe the importance of telemedicine in kidney transplantation, one article describes the importance of robot assistance in kidney transplantation, and two articles highlight new techniques for transplanting kidneys in rats and mice.

TBase is an electronic health record (EHR) for kidney transplant recipients (KTR) that automatically collects relevant clinical data collected during treatment¹. It is a comprehensive database for KTR that is critical for both clinical care and research. The EHR has been used for transplant outpatient care, and its utility is underscored by 20 years of use at Charité Hospital in Berlin. Long-term data are easily recovered by the system and may be used for research. The importance of the EHR is documented by many scientific publications^6,7,8,9,10. Overall, 7,595 kidney transplants have been documented with 6,489 sets of donor data. Data on an additional 20,724 renal non-transplanted patients with different conditions have been collected. Several papers have documented the importance of telemedicine as applied to kidney transplantation^11,12,13,14.

A system to facilitate bidirectional communication was implemented as fully described in the paper from Duettmann et al.². Indeed, the use of the MACCS platform for KTR patients allows for video conferences involving the kidney center, the local nephrologist, and the patients, who do not need to move to reach the hospital. In the first 5 months after its implementation, 131 patients actively participated in the project. This telemedicine system is cost-effective and may improve patient care¹⁵. A systematic improvement of the system is planned. It is being extended to non-transplanted renal patients and patients transplanted with different organs. The utility of these systems has already been documented during the COVID-19 pandemic^16,17 and in countries with long travel distances between medical centers, such as Canada and Australia¹⁸.

The paper from Lim et al.³ describes their experience of the important issue of robot-assisted kidney transplantation (RAKT) from living donors. RAKT can reduce postoperative pain and the number of wound infections¹⁹. In expert hands, RAKT also allows for kidney transplantation in obese patients²⁰. The authors describe the steps used for RAKT, with the most important being the positioning of the robotic and gel ports. Positioning the kidney allograft, reperfusion, and ureteroneocystostomy are also important steps in this technique. One of the principal advantages of RAKT is the reduction of all the operative times. RAKT is used with regional hypothermia to further reduce post-transplant complications and patient discomfort²¹. All of these data were validated by an updated analysis from the ERUS-RAKT including almost 300 cases²². Finally, the feasibility and safety of RAKT from deceased donors were documented²³ by expert teams, representing a new era for this technique.

The important aspect of the study of You et al.⁴ is that it modifies the model for rat orthotopic renal transplantation. Clinical trials are always preceded by studies on animals, and rat transplantation is an important model to study renal allograft rejection behavior in preclinical studies. Achieving renal allografts in rat models is essential, and rat transplantation should be free of surgical complications related to the surgical technique. Originally, the techniques used included the anastomosis of the donor rat renal artery and renal vein to the recipient rat aorta and inferior vena cava^24,25. However, these techniques can lead to lower body ischemia, which is often associated with thrombosis of the inferior vena cava and death of the recipient rat. Other researchers tried to anastomose the ureter using the cuff method, but the technique did not improve the outcomes²⁶. You et al.⁴ propose a different technique by which the donor’s kidney vessels are implanted directly into the recipient’s renal vessels. This method increases the survival and avoids obstacles to vascularizing the lower body.

Similar data were provided by Yin et al.⁵. They describe in detail a further technique for transplanting kidneys in mice. Essentially, they prepare a patch of the abdominal aorta, and the kidneys are taken en bloc, including the ureteral artery, to avoid ureteral necrosis or occlusion. They can also increase or decrease the anastomosis to avoid vessel strictures. In this way, they obtained good results, as documented by a previous study²⁷. In particular, they documented excellent histological results after the sacrifice of the mice²⁸.

In conclusion, the five articles in this methods collection all contribute toward the future of kidney transplantation. The two articles^1,2 on telemedicine focus on a topic that is important for facilitating the relationship among transplant centers, renal patients, and local nephrologists. In particular, telemedicine has been shown to be useful during the COVID-19 pandemic and in countries with very long travel distances. RAKT³, when used by skilled teams, is superior to open surgery. The improved surgical techniques developed during mice kidney transplantation^4,5 can increase rodent survival and eventually lead to preclinical studies with better operating conditions.