Introduction: Chronic kidney disease (CKD) often progresses to end stage kidney disease (ESKD), necessitating Kidney Replacement Therapy (KRT) to sustain life. The primary KRT options include kidney transplantation, maintenance haemodialysis (HD), and peritoneal dialysis (PD). While kidney transplantation is considered the gold standard, its availability is limited by logistic issues and donor shortages. More than 4 million patients are on dialysis across the globe. Dialysis serves as a vital KRT for those with (ESKD), filtering waste and excess fluids from the blood. HD is the most prevalent form of dialysis globally, accounting for approximately 80% of treatments. PD, a home-based therapy, is utilized by about 10% of dialysis patients. The choice between HD and PD often depends on factors such as healthcare infrastructure, patient preference, and economic considerations. While its prevalence varies by region, PD is particularly popular in countries like Hong Kong, South Africa and Mexico, where it constitutes a significant proportion of KRT.

Tree Top Hospital has been providing Hemodiafiltration (HDF), an advanced form of haemodialysis, since its inception seven years ago. HDF offers significant survival benefits to ESKD patients. Launched in December 2024, this initiative represents a major step forward in nephrology care in the region. By introducing PD, Tree Top Hospital empowers patients with greater flexibility and control over their treatment, allowing them to lead more fulfilling lives while managing their condition aligning with its vision of patient-centric dialysis care of the hospital. This article explores these two therapies, their benefits, and their role in transforming renal care in the Maldives.

Hemodiafiltration: An advancing dialysis care

HDF has emerged as a significant advancement in dialysis therapy, evolving from conventional HD to improve patient outcomes, particularly in those with ESKD. Conventional HD, introduced in the 1960s, relies on diffusion to remove small molecules and toxins from the bloodstream. However, it has limitations in clearing larger and middle-molecular-weight uremic toxins, which are linked to inflammation, cardiovascular complications, and poor survival rates. To overcome these challenges, HDF was developed as a hybrid therapy combining both diffusion and convection, enhancing solute removal across a broader molecular spectrum. The concept of convective therapy originated in the 1970s with hemofiltration, which used large fluid volumes to clear middle molecules but required significant fluid replacement. Over time, technological advancements in dialyzers, ultrafiltration control, and online fluid replacement enabled the transition to modern online hemodiafiltration (OL-HDF), which optimizes both clearance and hemodynamic stability.

Adoption of OL-HDF has been driven by accumulating clinical evidence demonstrating its benefits over standard HD. Large randomized controlled trials, such as the ESHOL, CONTRAST, and TURKISH HDF studies, have shown significant benefits with survival advantage and minimum dialysis-related symptoms like hypotension, inflammation, and oxidative stress. Notably, the CONVINCE trial, published in the New England Journal of Medicine (NEJM)in 2023, demonstrated a significant reduction in all-cause mortality among patients receiving high-dose HDF compared to those on conventional high-flux HD. Additionally, OL-HDF enhances biocompatibility and provides a more physiologic filtration process, closely mimicking kidney function. The introduction of high-flux dialyzers and precise fluid management systems has made HDF more efficient and widely accessible. At Tree Top Hospital, we provide OL-HDF using high flux hemodialyzers and ultrapure water. Also, we follow the international guidelines for water surveillance to generate ultrapure water.

Peritoneal Dialysis: A Patient-Centric Kidney Replacement Therapy

Peritoneal dialysis (PD) has evolved as a pivotal KRT, offering a home-based alternative to haemodialysis (HD). The concept of PD dates back to the early 20th century when clinicians recognized the peritoneal membrane as a natural semi-permeable barrier for fluid and solute exchange. The first successful human PD treatments were attempted in the 1920s, but widespread clinical application remained limited due to technical challenges, infection risks, and inadequate dialysate solutions. In the 1960s, the introduction of continuous ambulatory peritoneal dialysis (CAPD) by Dr. Henry Tenckhoff, along with the development of soft, indwelling peritoneal catheters, revolutionized PD by enabling long-term outpatient dialysis. Over time, improvements in biocompatible dialysate solutions, better infection control strategies, and automated peritoneal dialysis (APD) systems have made PD a viable, patient-centered alternative for individuals with end-stage kidney disease (ESKD). Despite its benefits, PD adoption remains limited in many regions due to concerns about peritonitis, patient training barriers, and healthcare infrastructure. However, with ongoing innovation in PD solutions, telemedicine-based monitoring, and assisted PD programs, the therapy continues to evolve, reinforcing its role as a sustainable, patient-friendly option in global nephrology care.

Mechanism of Solute Removal and Peritoneal Dialysis Fluids

PD relies on the peritoneal membrane, a highly vascularized natural barrier in the abdomen, to facilitate the exchange of solutes and fluid between blood and dialysate. The mechanism of solute removal occurs through three primary processes: diffusion, ultrafiltration, and convection. Diffusion allows small solutes, such as urea and creatinine, to move from the blood (higher concentration) to the dialysate (lower concentration) along a concentration gradient. Ultrafiltration occurs via osmosis, where a hypertonic glucose-based dialysate draws excess water from the bloodstream into the peritoneal cavity. Convection enhances solute clearance as water movement drags larger molecules across the peritoneal membrane. PD solutions include glucose-based, icodextrin-based, and amino acid-based dialysates, each tailored to address specific patient needs, such as fluid overload, glucose control, and nutritional supplementation. The continuous advancements in PD fluids, including low-glucose degradation product (GDP) solutions, have improved biocompatibility and reduced peritoneal membrane damage, ensuring better long-term PD outcomes.

Advantages of Peritoneal Dialysis over Haemodialysis or hemodiafiltration:

Peritoneal dialysis offers several benefits compared to maintenance haemodialysis:

1. Home-Based Treatment: PD can be performed at home, reducing the need for frequent hospital visits and providing patients with greater convenience.

2. Lifestyle Flexibility: Patients can integrate PD into their daily routines, maintaining work and social commitments with minimal disruption.

3. Preserved Residual Kidney Function: Studies have shown that PD better preserves residual kidney function, which is crucial for overall health and long-term outcomes.

4. Reduced Cardiovascular Strain: Unlike haemodialysis, PD avoids rapid fluid shifts, reducing the risk of cardiovascular complications.

5. Lower Infection Risk: While infection is a concern in both modalities, PD patients face a reduced risk of bloodstream infections compared to those undergoing haemodialysis.

Peritoneal Dialysis at Tree Top Hospital

CAPD was introduced at Tree Top Hospital in December 2024. Catheter insertion was performed using two different approaches: surgical (laparoscopic) insertion and the minimally invasive percutaneous technique. Patients undergoing CAPD with catheter inserted through both methods have shown good clinical outcomes.

CAPD typically involves 3 to 4 exchanges per day. Each exchange consists of:

1.        Drain Phase – Removal of used dialysis fluid from the abdominal cavity.

2.        Fill Phase – Infusion of fresh dialysis solution into the peritoneal cavity.

Patient-centric dialysis care at Tree Top Hospital:

With the advent of peritoneal dialysis (PD) and incremental dialysis techniques, kidney replacement therapy (KRT) can now be customized to align with a patient’s unique needs, cultural background, and personal values. Patients newly diagnosed with kidney failure have the autonomy to choose between peritoneal dialysis or hemodialysis based on their convenience, medical needs, and financial considerations, ensuring a more individualized and patient-centric approach to care.

The Future of Dialysis at Tree Top Hospital

With seven years of excellence in patient care, Tree Top Hospital continues to lead the way in nephrology services by offering both Haemodiafiltration (HDF) and Peritoneal Dialysis (PD). These therapies provide patients with choices tailored to their medical needs and lifestyle preferences.

The hospital’s vision for the future includes:

• Expanding HDF services to benefit more dialysis patients.
• Enhancing PD accessibility, allowing more patients to opt for home-based dialysis.
• Integrating advanced dialysis monitoring technologies for better patient outcomes.

Conclusion

Tree Top Hospital remains committed to delivering world-class kidney care, ensuring that patients with ESKD receive the best treatment options available. Whether through HDF for enhanced clearance and stability or PD for home-based flexibility, the hospital continues to set new benchmarks in nephrology care in the Maldives.

As Tree Top Hospital marks its seventh anniversary, its unwavering dedication to patient-centric care and innovation in dialysis therapies remains at the forefront, transforming lives and setting the standard for kidney care in the Maldives.

Dr Jaya Prakash Nath Ambinathan

Consultant Nephrologist
Tree Top Hospital