Risk Factors And Management Of Peritoneal Dialysis Catheter Malfunction

Background:Peritoneal dialysis(PD)is an effective renal replacement therapy(RRT)which has been widely used in the world due to its advance in easy operation,home treatment and portability.PD catheter,the "lifeline" of PD patients,its dysfuntion will result in delayed treatment,technical failure,even permanent withdrawal of PD.The incidence of PD catheter dysfunction is as high as 9.5% to 62.4%.However,there is still lack of convincing research on the risk factors of PD catheter dysfunction and practical treatment.Elaborating on the risk factors of PD catheter dysfunction will contribute to reducing the technical failure rate and elongating the lifetime of PD.This research will expound from three aspects: meta-analysis to summarize the influence of different PD catheter types on catheter dysfunction,retrospective analysis to explore the risk factors of PD catheter dysfunction and management measures,and prospective study to investigate the influence of intestinal preparation on catheter dysfunction.Contents:Part I: A network meta-analysis of randomized controlled trials was conducted to compare the complication and catheter survival in four commonly used peritoneal dialysis catheters(Tenckhoff segment with straight tip,Tenckhoff segment with coiled tip,swan neck segment with straight tip,and swan neck segment with coiled tip).Part II: A single-center,large-sample retrospective study was conducted to investigate the safety of urgent-start peritoneal dialysis(PD)and identify the risk factors of catheter dysfunction in order to establish predictive models of PD catheter dysfunction using a variety of machine learning methods.Part III: A randomized controlled trial was conducted to evaluate the efficacy and safety of preoperative enema in preventing catheter dysfunction in peritoneal dialysis.Methods:Part I: Randomized clinical trials were searched from Pub Med,Embase,the Cochrane Register of clinical trials,China National Knowledge Infrastructure and China Info from their inception until July 31,2022.Meta-analysis was performed using Stata 14.0 and Rev Man 5.3.5 software to evaluate the four commonly used PDCs.Part II: Patients who underwent urgent-start PD were divided into catheter-malfunction and control groups.Baseline demographic and laboratory data of the two groups were compared,and the risk factors for catheter malfunction were analyzed.Catheter malfunction types and management were reported.The risk factors of catheter dysfunction were analyzed by univariate and multifactorial Cox regression.Kaplan-Meier survival curve and Log-rank test were used to compare groups.Random survival forest(RSF),a machine learning algorithm,was used to build a prediction model.Data of patients with urgent-onset PD after open peritoneal dialysis catheterization in our center from January 1,2020 to December 31,2021 were prospectively collected.The generalization ability of the model was evaluated.C-index and area under receiver operating characteristic curve(AUC)at different time points were used to evaluate the differentiation of the model.The degree of calibration of the prediction model was evaluated using the integrated brier score(IBS).The net reclassification index(NRI)and integrated discrimination improvement(IDI)were used to compare the RSF model with the traditional Cox model.Part III: Prospective randomized controlled study: To investigate the efficacy and safety of preoperative enema in preventing peritoneal dialysis catheter dysfunction.According to strict inclusion and exclusion criteria,the patients were divided into the intervention group and the control group according to a randomized 1:1 ratio.The intervention group was given enema within 24 hours before surgery.The calculated sample size was about 68 cases per group.Study endpoints included primary and secondary endpoints.Primary endpoint included the occurrence of catheter dysfunction within 3 months after catheterization.Secondary endpoints included the occurrence of catheter dysfunction within 6 months after catheterization,catheter-free survival time / dysfunction timepoint within 3 and 6 months,occurrence and time of peritoneal dialysis-associated peritonitis and other catheter-related complications.Results:Part I: Seventeen studies involved 1578 participants were included.Network meta-analysis(NMA)showed that compared with Swan neck + C,Swan neck + S significantly reduced catheter tip migration(OR 0.47,95%CI 0.22-0.99).Tenckhoff + S was more effective in reducing catheter dysfunction(OR 0.42,95%CI 0.23-0.79),catheter tip migration with dysfunction(OR 0.19,95%CI 0.05-0.78)and catheter removal(OR0.56,95%CI 0.34-0.93)which were consistent with the pairwise meta-analysis.According to the surface under the cumulative ranking curve(SUCRA),Swan neck + S emerged as the best PDC in the reduction of catheter tip migration(83.3%),followed by Tenckhoff +S(79.4%).Moreover,Tenckhoff + S(86.5%,76.3%)and Swan neck + S(72.3,86.9%)ranked as the first and second PDC for one and two-year technique survival which was significantly higher than those of the other two PDCs.Part II: A total of 700 patients was analyzed,among whom 143(20.4%)experienced catheter malfunctions,specifically catheter migration(96,67.1%),omental wrapping(36,25.2%),and migration plus omental wrapping(11,7.7%).PD tube and subcutaneous tunnel preservation was successful in 41 out of 44 patients with omental wrapping.All patients had good post-incision prognoses.PD catheter survival time in the malfunction group(202.5 ± 479.4 days)was significantly shorter than that in the control group(1295.3± 637.0 days)(p < 0.001).Multivariate analysis revealed age(hazard ratio [HR],0.976,95% confidence intervals [CI],0.962–0.991;p = 0.002),body mass index(HR 1.061;95%CI,1.010–1.115;p = 0.018),surgeon(HR 1.083;95%CI,1.032–1.136;p = 0.036),serum potassium(HR,1.231;95%CI 1.041–1.494;p = 0.036),and no colonic dialysis(HR 0.384;95%CI 0.254–0.581;p < 0.001)as independent risk factors for catheter malfunction.Further subgroup analysis showed that patients with younger age(≤ 40 years)and higher serum potassium levels(≥ 5mmol/L)had shorter catheter-free survival,while patients with preoperative colon dialysis and experienced surgeons(≥ 50 times)had longer catheter-free survival.The predictive model was established by RSF and validated in 111 people prospectively collected.It was found that the C-index of the RSF model was0.881(95%CI 0.809-0.926),and the AUC value was higher than 0.9 at 90 days,180 days and 365 days.The IBS was 0.093(95%CI 0.091-0.097).Compared with the Cox model,RSF had higher predictive power,with a 180-day NRI of 0.713(95%CI 0.467-0.849,p <0.001)and IDI of 0.331(95%CI 0.205-0.442,p < 0.001).Part III: In prospective randomized controlled trial,a total of 159 patients who planned to receive long-term peritoneal dialysis renal replacement therapy for open surgery were screened,excluding five patients with an expected survival period of less than 3 months and eighteen patients who received laxative within 3 days before surgery.136 patients were finally enrolled and divided into enema group(n = 68)and control group(n = 68).Two cases were eliminated due to scrotal effusion and acute kidney injury respectively.There was no significant difference in baseline data between the two groups.All included patients completed 6 months of follow-up,and were included in the endpoint analysis.At3 months,the incidence of catheter dysfunction in enema group(10 cases)was lower than that in control group(25 cases),p = 0.005.At 6 months,there were 11 and 28 cases,respectively,p = 0.002.Catheter dysfunction required surgical intervention were 0 and 1case in enema and control group respectively.Kaplan-Meier survival curve analysis suggested that the 3-month catheter-free median survival time was 63.0 days(95%CI53.9-72.1)in the control group and 77.4 days(95%CI 70.1-84.7)in the enema group(p =0.004).At 6 months,the catheter-free median survival time was 118.3 days(95%CI99.3-137.4)in the control group and 152.8 days(95%CI 137.9-167.8)in the enema group(p = 0.002).The catheter-free survival time in the enema group was significantly higher than that in the control group at 3 and 6 months(p = 0.004,p = 0.002).Conclusion:1.The main influencing factors of PD catheter dysfunction include catheter type,preoperative intestinal preparation,patient age,operator experience and blood potassium level.2.Swan neck + S and Tenckhoff + S tended to be more efficacious than Swan neck + C and Tenckhoff + C in lowering the occurrence of mechanical dysfunction and prolonging the technical survival,which may contribute to better clinical decisions.More randomized controlled trials(RCTs)with larger scales and higher quality are needed in order to obtain more credible evidence.3.The results of single-center,large-sample retrospective study showed that colon dialysis before catheterization could significantly reduce the incidence of catheter dysfunction.Preliminary results of prospective randomized controlled trail also suggest that preoperative enema can significantly reduce the occurrence of catheter dysfunction,proving that preoperative intestinal preparation is an effective approach in reducing catheter dysfunction.4.RSF model has good predictive efficacy in PD catheter dysfunction,which may provide references for early prediction and intervention in poor prognosis PD patients.5.Urgent-start PD is safe and effective for unplanned PD patients.Conservative treatment is effective in managing catheter migration alone,while preservation of the PD tube and the subcutaneous tunnel is effective for omental wrapping.