Incremental Hemodialysis: Review of Clinical Trials Focused on Patients Undergoing Once-Weekly Hemodialysis

Background/objectives: The implementation of appropriate hemodialysis treatment in the transition from end-stage kidney disease to reduced frequency schedules represents a major challenge. The aim of our work is to report only treatment protocols that used once-weekly hemodialysis. Methods: The benefits and risks of 1WHD were explored in this systematic review. A search of MEDLINE, Scopus, and the Cochrane Central Register was conducted to identify publications relating to once-weekly hemodialysis trials performed between June 1981 and December 2024 and assess clinical impact, duration, safety, and mortality. Items, including age, causes of chronic kidney disease (CKD), creatinine levels, Blood Urea Nitrogen and GFR values, diuresis, nutritional supplementation, drop-out, survival, clinical benefit or drawbacks, and data from eventual control groups relating to higher frequency weekly HD sessions were included. Outcome at the end of a 1WHD regimen was represented by death or transition to twice/thrice-weekly HD rhythms. Results: A total of 1238 articles focused on IHD were included in the review, and 1226 trials were excluded as they referred either to twice-weekly hemodialysis (2WHD) schedules or failed to meet eligibility criteria, whilst another two were excluded based on incomplete outcome or patient recruitment issues. A total of eight articles comprising 254 patients undergoing 1WHD schedules were ultimately identified and evaluated. Only three studies focused on a comparison with a 1WHD schedule, whilst 107 referred to thrice-weekly HD (3WHD) and 15 2WHD). This choice demonstrated the possibility of slowing down the progression of CKD in the patients studied. Daily amino acid supplementation also proved to be beneficial. However, the milestone on which the 1WHD protocol is based is a low-protein diet. Conclusions: 1WHD has been shown to be safe and may result in improved clinical outcomes, particularly in appropriately selected patients. Large-scale randomized controlled trials should be carried out to confirm these potential advantages. However, the standard recruitment techniques applied tended to prevent suitably selected patients from transitioning into less frequent and potentially long-lasting 1WHD schedules.