Machine perfusion use for combined staged kidney transplantation after heart re‐transplantation: keep calm and stabilize the recipient!

Dual organ transplantation: when heart alone is not enough

PURPOSE OF REVIEW

The number of dual organ transplantations (DOT) are steadily increasing over the past few years. This is both a reflection of increasing complexity and advanced disease process in the patients and greater transplant center experience with performing dual organ transplants. Due to lack of standardization of the process, there remains significant center-based variability in patient selection, perioperative and long-term management of these patients.

RECENT FINDINGS

Overall posttransplant outcomes for DOT have been acceptable with some immunological advantages because of partial tolerance offered by the second organ. These achievements should, however, be balanced with the ethical implications of bypassing the patients who are listed for single organ transplantation because of the preferential allocation of organs for DOT.

SUMMARY

The field of DOT is expanding rapidly, with good long-term outcomes. There is an urgent need for guidelines to standardize the process of patient selection and listing dual organ transplantation.

Overcoming challenges in patient selection and monitoring in combined heart and kidney transplantation

Combined heart-kidney transplantation (HKT) is a growing therapeutic strategy in patients with advanced heart failure (HF) and concomitant chronic kidney disease (CKD). Although patients with advanced HF and need for chronic haemodialysis have a clear indication for combined HKT, challenges to current practice lie in identifying those patients with severely depressed kidney function, which will not recover kidney function after restoration of appropriate haemodynamic conditions following heart transplantation (HT) alone. Because of the paucity of available organs, maximisation of kidney graft utility whilst minimising the operative risks associated with combined transplantation is mandatory. The benefits of HKT go beyond the mere restoration of kidney function. Data from registry analysis show that HKT improves overall survival in patients with CKD, as compared to heart transplant only, and it is associated with reduced incidence of heart allograft rejection, likely through the promotion of host immune tolerance mechanisms. In patients not requiring chronic dialysis, kidney-after-heart strategy may be explored, instead of combined HKT, in particular when the aetiology of CKD is unclear. This indeed allows for monitoring and gaging of indications for combined transplantation in the postoperative period. This approach however should be matched with priority listing for kidney transplantation given the high waitlist mortality in heart transplant recipients with associated CKD. The use of kidney machine perfusion may represent an additional tool to optimise the outcome of HKT, allowing more time to stabilise the patient after HT surgery.

Hypothermic machine perfusion can safely prolong cold ischemia time in deceased donor kidney transplantation. A retrospective analysis on postoperative morbidity and graft function

In deceased donor kidney transplantation (KT), a prolonged cold ischemia time (CIT) is a negative prognostic factor for KT outcome, and the efficacy of hypothermic machine perfusion (HMP) in prolonging CIT without any additional hazard is highly debated. We conducted a retrospective study on a cohort of 154 single graft deceased donor KTs, in which a delayed HMP, after a preliminary period of static cold storage (SCS), was used to prolong CIT for logistic reasons. Primary outcomes were postoperative complications as well as 1 year graft survival and function. 73 cases (47.4%) were managed with HMP and planned KT, while 81 (52.6%) with SCS and urgent KT. The median CIT in HMP group and SCS group was 29 hour:57 minutes [27-31 hour:45 minutes] and 11 hour:25 minutes [9-14 hour:30 minutes], respectively (P < .001). The period of SCS in the HMP group was significantly shorter than in the SCS group (10 vs. 11 hour:25 minutes, P = .02) as well as the prevalence of expanded criteria donors was significantly higher (43.8% vs. 18.5%, P < .01). After propensity score matching for these two baseline characteristics, the HMP and SCS groups showed comparable outcomes in terms of delayed graft function, vascular, and urologic complications, infections, and episodes of graft rejection. At 1 year follow-up, serum creatinine levels were comparable between the groups. Therefore, the use of HMP to prolong the CIT and convert KT into a planned procedure seemed to have an adequate safety profile, with outcomes comparable to KT managed as an urgent procedure and a CIT nearly three time shorter.