Home dialysis: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference.

Home dialysis modalities (home hemodialysis [HD] and peritoneal dialysis [PD]) are associated with greater patient autonomy and treatment satisfaction compared with in-center modalities, yet the level of home-dialysis use worldwide is low. Reasons for limited utilization are context-dependent, informed by local resources, dialysis costs, access to healthcare, health system policies, provider bias or preferences, cultural beliefs, individual lifestyle concerns, potential care-partner time, and financial burdens. In May 2021, KDIGO (Kidney Disease: Improving Global Outcomes) convened a controversies conference on home dialysis, focusing on how modality choice and distribution are determined and strategies to expand home-dialysis use. Participants recognized that expanding use of home dialysis within a given health system requires alignment of policy, fiscal resources, organizational structure, provider incentives, and accountability. Clinical outcomes across all dialysis modalities are largely similar, but for specific clinical measures, one modality may have advantages over another. Therefore, choice among available modalities is preference-sensitive, with consideration of quality of life, life goals, clinical characteristics, family or care-partner support, and living environment. Ideally, individuals, their care-partners, and their healthcare teams will employ shared decision-making in assessing initial and subsequent kidney failure treatment options. To meet this goal, iterative, high-quality education and support for healthcare professionals, patients, and care-partners are priorities. Everyone who faces dialysis should have access to home therapy. Facilitating universal access to home dialysis and expanding utilization requires alignment of policy considerations and resources at the dialysis-center level, with clear leadership from informed and motivated clinical teams.

Catheter insertion techniques for improving catheter function and clinical outcomes in peritoneal dialysis patients.

BACKGROUND: Peritoneal dialysis (PD) relies on the optimal functionality of the flexible plastic PD catheter present within the peritoneal cavity to enable effective treatment. As a result of limited evidence, it is uncertain if the PD catheter's insertion method influences the rate of catheter dysfunction and, thus, the quality of dialysis therapy. Numerous variations of four basic techniques have been adopted in an attempt to improve and maintain PD catheter function. This review evaluates the association between PD catheter insertion technique and associated differences in  PD catheter function and post-PD catheter insertion complications OBJECTIVES: Our aims were to 1) evaluate if a specific technique used for PD catheter insertion has lower rates of PD catheter dysfunction (early and late) and technique failure; and 2) examine if any of the available techniques results in a reduction in post-procedure complication rates including postoperative haemorrhage, exit-site infection and peritonitis. SEARCH METHODS: We searched the Cochrane Kidney and Transplant Register of Studies up to 24 November 2022 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. SELECTION CRITERIA: We included randomised controlled trials (RCTs) examining adults and children undergoing PD catheter insertion. The studies examined any two PD catheter insertion techniques, including laparoscopic, open-surgical, percutaneous and peritoneoscopic insertion. Primary outcomes of interest were PD catheter function and technique survival.  DATA COLLECTION AND ANALYSIS: Two authors independently performed data extraction and assessed the risk of bias for all included studies. Main outcomes in the Summary of Findings tables include primary outcomes - early PD catheter function, long-term PD catheter function, technique failure and postoperative complications. A random effects model was used to perform meta-analyses; risk ratios (RRs) were calculated for dichotomous outcomes, and mean differences (MD) were calculated for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. The certainty of the evidence was evaluated using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach.  MAIN RESULTS: Seventeen studies were included in this review. Nine studies were suitable for inclusion in quantitative meta-analysis (670 randomised participants). Five studies compared laparoscopic with open PD catheter insertion, and four studies compared a 'medical' insertion technique with open surgical PD catheter insertion: percutaneous (2) and peritoneoscopic (2). Random sequence generation was judged to be at low risk of bias in eight studies. Allocation concealment was reported poorly, with only five studies judged to be at low risk of selection bias. Performance bias was judged to be high risk in 10 studies. Attrition bias and reporting bias were judged to be low in 14 and 12 studies, respectively. Six studies compared laparoscopic PD catheter insertion with open surgical insertion. Five studies could be meta-analysed (394 participants). For our primary outcomes, data were either not reported in a format that could be meta-analysed (early PD catheter function, long-term catheter function) or not reported at all (technique failure). One death was reported in the laparoscopic group and none in the open surgical group. In low certainty evidence, laparoscopic PD catheter insertion may make little or no difference to the risk of peritonitis (4 studies, 288 participants: RR 0.97, 95% CI 0.63 to 1.48; I² = 7%), PD catheter removal (4 studies, 257 participants: RR 1.15, 95% CI 0.80 to 1.64; I² = 0%), and dialysate leakage (4 studies, 330 participants: RR 1.40, 95% CI 0.49 to 4.02; I² = 0%), but may reduce the risk of haemorrhage (2 studies, 167 participants: RR 1.68, 95% CI 0.28 to 10.31; I² = 33%) and catheter tip migration (4 studies, 333 participants: RR 0.43, 95% CI 0.20 to 0.92; I² = 12%). Four studies compared a medical insertion technique with open surgical insertion (276 participants). Technique failure was not reported, and no deaths were reported (2 studies, 64 participants). In low certainty evidence, medical insertion may make little or no difference to early PD catheter function (3 studies, 212 participants: RR 0.73, 95% CI 0.29 to 1.83; I² = 0%), while one study reported long-term PD function may improve with peritoneoscopic insertion (116 participants: RR 0.59, 95% CI 0.38 to 0.92). Peritoneoscopic catheter insertion may reduce the episodes of early peritonitis (2 studies, 177 participants: RR 0.21, 95% CI 0.06 to 0.71; I² = 0%) and dialysate leakage (2 studies, 177 participants: RR 0.13, 95% CI 0.02 to 0.71; I² = 0%). Medical insertion had uncertain effects on catheter tip migration (2 studies, 90 participants: RR 0.74, 95% CI 0.15 to 3.73; I² = 0%). Most of the studies examined were small and of poor quality, increasing the risk of imprecision. There was also a significant risk of bias therefore cautious interpretation of results is advised. AUTHORS' CONCLUSIONS: The available studies show that the evidence needed to guide clinicians in developing their PD catheter insertion service is lacking. No PD catheter insertion technique had lower rates of PD catheter dysfunction. High-quality, evidence-based data are urgently required, utilising multi-centre RCTs or large cohort studies, in order to provide definitive guidance relating to PD catheter insertion modality.

Longitudinal bioimpedance vector plots add little value to fluid management of peritoneal dialysis patients.

Bioimpedance (BI) has the potential to enable better management of fluid balance, which can worsen over time on peritoneal dialysis (PD) due to loss of residual kidney function and progressive muscle wasting. We undertook a prospective, randomized, open-label, blinded end-point controlled trial to determine whether availability of longitudinal BI measures as vector plots helped clinicians maintain stable fluid status over 12 months in 308 peritoneal dialysis patients from the United Kingdom and Shanghai, China. Patients were recruited into 4 groups nested within a single trial design according to country and residual kidney function. Nonanuric subjects from both countries demonstrated stable fluid volumes irrespective of randomization. Hydration worsened in control anuric patients in Shanghai with increased extracellular/total body water (ECW/TBW) ratio (0.04; 95% CI: 0.01, 0.06) and reduced TBW (-1.76 L 95% CI: -2.70, -0.82), but was stable in the BI intervention group whose dialysate glucose prescription was increased. However, multilevel analysis incorporating data from both countries showed worsening ECW/TBW in active and control anuric patients. Clinicians in the United Kingdom reduced target weight in the nonanuric BI intervention group causing a reduction in TBW without beneficial effects on ECW or blood pressure. Thus, routine use of longitudinal BI vector plots to improve clinical management of fluid status is not supported.

Respecting shape memory to optimize peritoneal dialysis catheter outcomes.

Disruption of the shape memory of a peritoneal dialysis catheter at the time of insertion may be a factor responsible for tip migration and catheter dysfunction. The use of postimplantation radiology to confirm the preservation of both the swan neck angle and the inclination angle may have a role in standardizing insertion technique with the potential to reduce the impact of operator variation on catheter outcomes.

Advanced Laparoscopic Peritoneal Dialysis Catheter Insertion: Systematic Review and Meta-Analysis.

BACKGROUND: The optimal methodology of establishing access for peritoneal dialysis (PD) remains controversial. Previously published randomized controlled trials and cohort studies do not demonstrate an advantage for 1 technique over another. Four published meta-analyses comparing outcomes of laparoscopic versus open PD catheter (PDC) insertion have given inconsistent conclusions and are flawed since they group basic and advanced laparoscopy together. The aim of this systematic review and meta-analysis is to examine whether advanced laparoscopic interventions consisting of rectus sheath tunneling and adjunctive procedures produce a better outcome than open insertion or basic laparoscopy used only to verify the catheter position. METHODS: A literature search using Medline, Embase, and Cochrane Database was performed, and meta-analysis was performed using RevMan 5.3.5 software (Nordic Cochrane Centre, The Cochrane Collaboration, London, UK). Outcomes evaluated incidence of catheter obstruction, migration, pericannular leak, hernia, infectious complications (peritonitis and exit-site infection) and catheter survival. RESULTS: Of the 467 records identified, 7 cohort studies, including 1,045 patients, were included in the meta-analysis. When advanced laparoscopy was compared with open insertion, a significant reduction was observed in the incidence of catheter obstruction (odds ratio [OR] 0.14, 95% confidence interval [CI] 0.03 - 0.63; p = 0.01), catheter migration (OR 0.12, 95% CI 0.06 - 0.26; p = 0.00001), pericannular leak (OR 0.27, 95% CI 0.11 - 0.64; p = 0.003), and pericannular and incisional hernias (OR 0.29, 95% CI 0.09 - 0.94; p = 0.04), as well as better 1- and 2-year catheter survival (OR 0.52, 95% CI 0.28 - 0.97; p = 0.04 and OR 0.50, 95% CI 0.28 - 0.92; p = 0.03, respectively). Compared with basic laparoscopy, catheter obstruction and migration were significantly lower in the advanced laparoscopic group, whereas catheter survival was similar in both groups. All outcomes, except catheter obstruction, were similar between the basic laparoscopy and open insertion. The infectious complications such as peritonitis and exit-site infections were similar between the 3 groups. CONCLUSIONS: Advanced laparoscopy was associated with a significant superior outcome in comparison with open insertion and basic laparoscopy.

An exploratory study of a novel peritoneal combination dialysate (1.36% glucose/7.5% icodextrin), demonstrating improved ultrafiltration compared to either component studied alone.

OBJECTIVE: Concerns regarding the impact of ultrafiltration failure on peritoneal dialysis and the effect of hypertonic glucose on the peritoneal membrane have lead to a search for alternative dialysates. Computer simulations based on the three-pore theory suggest that a combination of 1.36% glucose and 7.5% icodextrin (glucose polymer) offers an improved ultrafiltration profile. The aim of the present study was to investigate the ultrafiltration profile of this combination fluid. DESIGN: Prospective open study comparing 1.36% glucose, 3.86% glucose, 7.5% icodextrin, and the combination fluid (1.36% glucose/7.5% icodextrin). SETTING: Sheffield Kidney Institute, Northern General Hospital, Sheffield, UK. PATIENTS: 11 patients currently using peritoneal dialysis not previously exposed to icodextrin. MAIN OUTCOME MEASURE: Intraperitoneal volume was measured using a radioisotope dilution method. RESULTS: The combination fluid showed a biphasic ultrafiltration profile, with a steep initial increase in intraperitoneal volume, then a maintained plateau phase for the duration of the study dwell (7 hours). The final volume was greater than that with the 1.36% glucose dwell and the 7.5% icodextrin dwell. The fluid was well tolerated by the patients. CONCLUSIONS: These findings are in keeping with computer simulations using the three-pore model. The combination fluid offers an improved ultrafiltration profile, with a final volume similar to 3.86% glucose, while avoiding exposing the peritoneal membrane to high glucose concentrations. It may have a role as a long dwell to optimize ultrafiltration and possibly prolong peritoneal dialysis technique survival.

Enhanced ultrafiltration using 7.5% icodextrin/1.36% glucose combination dialysate: a pilot study.

OBJECTIVE: A pilot study to compare the use of a combination dialysate (7.5% icodextrin/1.36% glucose) versus icodextrin 7.5% alone for the long dwell in patients on peritoneal dialysis (PD). DESIGN: A 4-week, prospective, randomized crossover study. SETTING: A large regional renal unit providing treatment for a population of 1.7 million. PATIENTS: Five patients on continuous ambulatory PD (CAPD) and 3 patients on automated PD. MAIN OUTCOME MEASUREMENTS: Long-dwell and 24-hour ultrafiltration volumes, body weight, 24-hour ambulatory blood pressure, and antihypertensive/diuretic tablet count. RESULTS: The use of the combination dialysate resulted in an increase in the median (interquartile range) long-dwell ultrafiltration, from 750 (650-828) mL to 1000 (889-1100) mL (p < 0.001), and 24-hour ultrafiltration, from 739 (400-1623) mL to 956 (700-1750) mL (p < 0.001). Weight, blood pressure, and tablet count remained unchanged. CONCLUSIONS: The use of the novel combination dialysate resulted in a 33% increase in long-dwell ultrafiltration and a 29% increase in 24-hour ultrafiltration.

Bone mineral metabolism parameters and urinary albumin excretion in a representative US population sample.

BACKGROUND AND HYPOTHESIS: Even within accepted normal ranges, higher serum phosphorus, dietary phosphorus density, parathyroid hormone (PTH) and alkaline phosphatase (ALP) are independent predictors of cardiovascular mortality. Lower serum 25-hydroxy vitamin D (25(OH)D) also predicts adverse cardiovascular outcomes. We hypothesized that vascular dysfunction accompanying subtle disturbances of these bone metabolism parameters would result in associations with increased low grade albuminuria. STUDY POPULATION AND MEASURES: We examined participants in the National Health and Nutrition Examination Surveys 1999-2010 (N = 19,383) with estimated glomerular filtration rate (eGFR) ≥60 ml/min/1.73 m² and without severe albuminuria (urine albumin:creatinine ratio (ACR) <300 mg/g). Albuminuria was quantified as ACR and fractional albumin excretion (FE(alb)). RESULTS: Increasing quintiles of dietary phosphorus density, serum phosphorus and ALP were not associated with higher ACR or FE(alb). The lowest versus highest quintile of 25(OH)D was associated with greater albuminuria, but not after adjustment for other covariates including cardiovascular risk factors. An association between the highest versus lowest quintile of bone-specific ALP and greater ACR persisted after covariate adjustment, but was not accompanied by an independent association with FE(alb). Increasing quintiles of PTH demonstrated associations with both higher ACR and FE(alb) that were not abolished by adjusting for covariates including age, gender, race, body mass index, diabetes, blood pressure, history of cardiovascular disease, smoking, eGFR, 25(OH)D, season of measurement, lipids, hemoglobin and C-reactive protein. Adjusted increases in ACR and FE(alb) associated with the highest versus lowest quintile of PTH were 19% (95% confidence interval 7-28% p<0.001) and 17% (8-31% p = 0.001) respectively. CONCLUSION: In this population, of the bone mineral parameters associated with cardiovascular outcomes, only PTH is independently associated with ACR and FE(alb).

The Stoke contribution to peritoneal dialysis research.

The Stoke Renal Unit has been at the forefront of peritoneal dialysis (PD) research for much of the past two decades. Central to this work is the PD cohort study, which was started in 1990 and is based on regular outpatient measurements of peritoneal and clinical function, correlating these with long-term outcomes. It has provided a wealth of information on risk factors for morbidity and mortality in patients on PD, the most significant being demonstration of the effects of time and dialysate glucose exposure on changes to the peritoneal membrane, as evidenced by increases in small solute transport. Early on, the study confirmed the adverse relationship between high small-solute transport status and outcome but more recently suggested that this relationship no longer held with modern techniques for managing patients on PD. Central themes of the PD research in Stoke have included evaluation of euvolemia, the importance of ultrafiltration and how best to achieve it, and detailed assessments of transmembrane water movement. The work has included the study of sodium removal and the use of novel low sodium dialysates. More recently, attention has turned to the significance of impaired ultrafiltration capacity in patients on PD as a sign of structural membrane damage. It is hoped that further work in this area will identify preventive strategies.

The anatomy and pathology of the lesser sac: implications for peritoneal dialysis.

Pathological conditions involving the lesser sac of the peritoneal cavity in patients on peritoneal dialysis (PD) can pose significant diagnostic and therapeutic challenges. Lack of appreciation of these challenges may delay diagnosis and compromise outcome. A case series by Li and colleagues in this issue of Peritoneal Dialysis International highlights the diagnostic challenges presented by lesser sac infection in PD patients, and in this accompanying commentary we discuss the development and anatomy of the lesser sac, as well as the pathological conditions and investigations relevant to the management of patients on PD.