Background: Paediatric kidney transplantation, particularly in children weighing less than 20 kg, presents unique challenges but has evolved significantly over the past decades. Advances in surgical techniques and immunosuppressive therapies have improved outcomes, with early transplantation offering benefits in growth, cognitive development, and long-term survival. This study aims to assess the outcomes of kidney transplantation in small paediatric recipients at the Red Cross War Memorial Children’s Hospital over a 20-year period.
Methods: Retrospective descriptive study for all kidney transplants performed from 2002 to 2022 in recipients weighing less than 20 kg.
Results: A total of 172 kidney transplants were performed during the study period, with 51 (29.7%) in recipients weighing less than 20 kg.  Two were part of a combined liver and kidney transplant due to primary hyperoxaluria. The median recipient age was 5 years, and the median weight at transplant was 14.5 kg. The most common causes of kidney failure included dysplasia (19.6%), posterior urethral valves (13.7%), and focal segmental glomerulosclerosis (9.8%).
Urinary tract infections post-transplant were noted in 47.9% of patients, Klebsiella being the most common cause. Of the 51 transplants, 15.7% (8 patients) experienced surgical complications. Three patients had vascular complications with graft loss in two due to renal vein thrombosis and a  successful re-do arterial anastomosis in the third. Three patients were able to be re-transplanted, two due to chronic rejection and one due to graft loss from venous thrombosis. Over the course of the study, patient survival at 1 and 5 year was 89.6% and 77%.  Graft survival at 1 and 5 year was 86.2% and 71.1% respectively.
Conclusion: This study highlights the feasibility of kidney transplantation in small paediatric recipients with promising short-term graft survival .The high incidence of urinary tract infections, recurrence of primary disease and surgical complications, particularly related to vascular issues, underscores the importance of refined surgical techniques, tailored perioperative care and early detection of post-transplant complications.  This study contributes valuable data to the growing body of evidence supporting early transplantation in children weighing less than 20 kg and provides a basis for enhancing outcomes. It also emphasize the need for continued advancements in paediatric kidney transplantation to improve long-term survival and quality of life for these vulnerable patients.