Interventional nephrology: current status and clinical impact in Japan

Upward-directed exit-site of the swan-neck catheter and "Easy-to-disinfect the backside area of exit-site" may prevent PD complications

BACKGROUND

Upward-directed exit-site has been believed to be the worst for frequent ESI by an old retrospective study using straight catheters. No comparison study of 3 exit-site directions using swan-neck catheter has been performed regarding which direction is the best for our endpoints, Easy-to-see the backside area of exit-site: ESBE, Easy-to-disinfect the backside area of exit-site: EDBE, reduction of both exit-site infection (ESI), symptomatic catheter dislocation and peritonitis.

METHODS

We assessed the relationship of exit-site direction with our endpoints in a quantitative cross-sectional, multicentered questionnaire survey. Patients who received either non-surgical catheter implantation or exit-site surgery were excluded.

RESULTS

The numbers (percentage) of exit-site directions in included 291 patients were upward 79 (26.0), lateralward 108 (37.5) and downward 105 (36.5). Cochran-Armitage analysis showed a significant step-ladder increase in the prevalence of ESI as the direction changed from upward to lateralward to downward (0.15 ± 0.41, 0.25 ± 0.54, 0.38 ± 0.69 episodes/patient-year, p = 0.03). Multivariable regression analysis revealed the upward exit-site independently associates with both higher frequency of ESBE (OR 5.55, 95% CI 2.23-16.45, p < 0.01) and reduction of prevalence of ESI (OR 0.55, 95%CI 0.27-0.98, p = 0.04). Positive association between the prevalence of symptomatic catheter dislocation and ESI (OR 2.84, 95% CI 1.27-7.82, p = 0.01), and inverse association between EDBE and either prevalence of symptomatic catheter dislocation (OR 0.27, 95% CI 0.11-0.72) or peritonitis (OR 0.48, 95% CI 0.23-0.99) observed.

CONCLUSION

Upward-directed swan-neck catheter exit-site may be the best for both ESBE and prevention of ESI. EDBE may reduce catheter dislocation and peritonitis. Symptomatic catheter dislocation may predict ESI.

Peritoneal Dialysis Catheter Complications after Insertion by Surgeons, Radiologists, or Nephrologists

SIGNIFICANCE STATEMENT

The Advancing American Kidney Health Initiative aims to increase rates of utilization of peritoneal dialysis (PD) in the United States. One of the first steps to PD is successful catheter placement, which can be performed by surgeons, interventional radiologists, or nephrologists. We examined the association between operator subspecialty and risk of needing a follow-up procedure in the first 90 days after initial PD catheter implantation. Overall, we found that 15.5% of catheters required revision, removal, or a second catheter placement within 90 days. The odds of requiring a follow-up procedure was 36% higher for interventional radiologists and 86% higher for interventional nephrologists compared with general surgeons. Further research is needed to understand how to optimize the function of catheters across different operator types.

BACKGROUND

The US government has implemented incentives to increase the use of PD. Successful placement of PD catheters is an important step to increasing PD utilization rates. Our objective was to compare initial outcomes after PD catheter placement by different types of operators.

METHODS

We included PD-naïve patients insured by Medicare who had a PD catheter inserted between 2010 and 2019. We examined the association between specialty of the operator (general surgeon, vascular surgeon, interventional radiologist, or interventional nephrologist) and odds of needing a follow-up procedure, which we defined as catheter removal, replacement, or revision within 90 days of the initial procedure. Mixed logistic regression models clustered by operator were used to examine the association between operator type and outcomes.

RESULTS

We included 46,973 patients treated by 5205 operators (71.1% general surgeons, 17.2% vascular surgeons, 9.7% interventional radiologists, 2.0% interventional nephrologists). 15.5% of patients required a follow-up procedure within 90 days of the initial insertion, of whom 2.9% had a second PD catheter implanted, 6.6% underwent PD catheter removal, and 5.9% had a PD catheter revision within 90 days of the initial insertion. In models adjusted for patient and operator characteristics, the odds of requiring a follow-up procedure within 90 days were highest for interventional nephrologists (HR, 1.86; 95% confidence interval [CI], 1.56 to 2.22) and interventional radiologists (odds ratio, 1.36; 95% CI, 1.17 to 1.58) followed by vascular surgeons (odds ratio, 1.06; 95% CI, 0.97 to 1.14) compared with general surgeons.

CONCLUSIONS

The probability of needing a follow-up procedure after initial PD catheter placement varied by operator specialty and was higher for interventionalists and lowest for general surgeons.

Safety of Renal Biopsy by Physicians with Short Nephrology Experience

Percutaneous renal biopsy is an essential tool for diagnosing various renal diseases; however, little is known about whether renal biopsy performed by physicians with short nephrology experience is safe in Japan. This study included 238 patients who underwent percutaneous renal biopsy between April 2017 and September 2020. We retrospectively analyzed the frequency of post-renal biopsy complications (hemoglobin decrease of ≥10%, hypotension, blood transfusion, renal artery embolization, nephrectomy and death) and compared their incidence among physicians with varied experience in nephrology. After renal biopsy, a hemoglobin decrease of ≥10%, hypotension and transfusion occurred in 13.1%, 3.8% and 0.8% of patients, respectively. There were no cases of post-biopsy renal artery embolism, nephrectomy, or death. The composite complication rate was 16.0%. The incidence of post-biopsy complications was similar between physicians with ≥3 years and <3 years of clinical nephrology experience (12.5% vs. 16.8%, p = 0.64). Furthermore, the post-biopsy composite complication rates were similar between physicians with ≥6 months and <6 months of clinical nephrology experience (16.3% vs. 15.6%, p > 0.99). Under attending nephrologist supervision, a physician with short clinical nephrology experience can safely perform renal biopsy.

The efficacy and safety of a novel method of peritoneal dialysis catheter insertion from the McBurney point

Background

Catheter dysfunction, especially omental wrapping, is a serious complication of peritoneal dialysis (PD). Although catheter implantation at a lower site was reported to prevent omental wrapping, this method could induce insufficient drainage of the PD solution and cause pain or a persistent desire to defecate, when the intraperitoneal catheter is of insufficient length or when its tip is in direct contact with the pelvic floor, respectively. The aim of this study was to assess the efficacy and safety of a novel PD catheter insertion method of approaching from the McBurney point, from the outer side of the abdomen.

Methods

This retrospective study included 23 patients with end-stage renal disease who were started on PD from January 2017 to July 2018 at Ashikaga Red Cross Hospital, Tochigi, Japan. Among them, 16 patients underwent a PD catheter insertion using a conventional method, whereas 7 patients underwent a novel method of approaching from the McBurney point. Infectious and mechanical complications were evaluated until August 2020.

Results

There were 18 men and 5 women, with a mean age of 63.1 ± 13.6 years. All patients were followed up postoperatively for a mean duration of 27.2 ± 13.4 months. No patient experienced omental wrapping, insufficient drainage of the PD solution, and pain or persistent desire to defecate in both groups. Both the incidence of infectious and mechanical complications (times per patient-year) were not statistically different between patients undergoing a conventional and a novel PD catheter insertion (0.18 vs. 0.24; p = 0.79 and 0.03 vs. 0.16; p = 0.16, respectively).

Conclusions

This novel method of PD catheter insertion from the McBurney point was safe, caused less discomfort, and was effective in preventing catheter dysfunction.

Minilaparotomy for malfunctioning peritoneal dialysis catheter by nephrologists: experiences at two centers

Catheter malfunction is one of the most important complications of peritoneal dialysis (PD). We have performed minilaparotomy for catheter repair by nephrologists. This study aimed to evaluate the effectiveness and safety of the surgery. The surgery was performed 11 times on 10 PD patients with catheter malfunction (3 man, 7 women; mean age 54.3 ± 14.6 years; 4 diabetes, 3 glomerulonephritis, 3 other) at two hospitals. All patients had inflow and/or outflow obstruction. One patient had inserted the PD catheter using conventional surgical technique, and the remaining nine patients had used Moncrief-Popovich technique. Seven patients with catheters embedded using the Moncrief-Popovich technique showed catheter occlusion at the time of externalization. The remaining three patients experienced catheter obstruction 6.0 ± 2.9 months after commencing PD. The cause of obstruction was fibrin in six patients, wrapping by fimbriae of the fallopian tube in two patients, omentum wrapping in two patients. One patient had no blockage in the catheter. Operative time was 97 ± 46 min, and no intraoperative complications were observed. PD was interrupted for 5.9 ± 3.0 days and was resumed without leakage in all patients. However, catheter malfunction recurred in one patient 3 months after the surgery. The mean hospital stay was 22.4 ± 14.7 days. Minilaparotomy by nephrologists is a safety and suitable for the management of catheter malfunction. In addition, it is necessary to always consider the possibility that the catheter has been occluded at the time of externalization in the Moncrief-Popovich technique.

Changes to indications for tunneled cuffed catheter use in hemodialysis patients: A single-center experience

INTRODUCTION

As the number of elderly end-stage renal disease patients lacking suitable vessels for arteriovenous fistula (AVF) is increasing, indications for tunnel cuffed catheters (TCCs) may be expanding. This study aimed to clarify changes over time in the number of patients with TCC and indications for TCCs.

METHODS

This single-center retrospective study analyzed 143 catheters for 95 patients who inserted TCCs between July 2005 and July 2017. Patients were divided into two groups (early- and late-phase groups) based on the median observational period. Demographic data and clinical information were then compared.

FINDINGS

Fifty TCCs were inserted in the early phase group, and 93 TCCs were inserted in the late-phase group. The late-phase group was older (77 vs. 70 years; P = 0.003) and showed a higher frequency of hypertensive nephropathy (29% vs. 14%; P < 0.05) and a lower frequency of a history of cardiovascular disease (52.7% vs. 70.0%; P = 0.045). In the late-phase group, indications for bridge vascular access (0% vs. 11.8%; P < 0.05) or severe cardiac dysfunction (8.0% vs. 20.5%; P < 0.05) were increased. In addition, the late-phase group showed increases in percentage of patients with the catheter inserted in the femoral vein (10.0% vs. 23.7%; P = 0.047), nephrologists performing catheter insertion (56.0% vs. 87.1%; P < 0.001), and the patients who underwent superficialization of the brachial artery (28.0% vs. 46.2%; P = 0.034). Significant differences in catheter survival, incidence of complications, reasons for catheter removal, or incidence of catheter-related infection were not observed between groups.

DISCUSSION

Patients with indications for TCC may be increasing due to an increase in elderly end-stage renal disease patients whose activities of daily living have decreased. In addition, indications for bridge vascular access were widely accepted in the late-phase group.

Where Are You Going, Nephrology? Considerations on Models of Care in an Evolving Discipline

Nephrology is a complex discipline, including care of kidney disease, dialysis, and transplantation. While in Europe, about 1:10 individuals is affected by chronic kidney disease (CKD), 1:1000 lives thanks to dialysis or transplantation, whose costs are as high as 2% of all the health care budget. Nephrology has important links with surgery, bioethics, cardiovascular and internal medicine, and is, not surprisingly, in a delicate balance between specialization and comprehensiveness, development and consolidation, cost constraints, and competition with internal medicine and other specialties. This paper proposes an interpretation of the different systems of nephrology care summarising the present choices into three not mutually exclusive main models (“scientific”, “pragmatic”, “holistic”, or “comprehensive”), and hypothesizing an “ideal-utopic” prevention-based fourth one. The so-called scientific model is built around kidney transplantation and care of glomerulonephritis and immunologic diseases, which probably pose the most important challenges in our discipline, but do not mirror the most common clinical problems. Conversely, the pragmatic one is built around dialysis (the most expensive and frequent mode of renal replacement therapy) and pre-dialysis treatment, focusing attention on the most common diseases, the holistic, or comprehensive, model comprehends both, and is integrated by several subspecialties, such as interventional nephrology, obstetric nephrology, and the ideal-utopic one is based upon prevention, and early care of common diseases. Each model has strength and weakness, which are commented to enhance discussion on the crucial issue of the philosophy of care behind its practical organization. Increased reflection and research on models of nephrology care is urgently needed if we wish to rise to the challenge of providing earlier and better care for older and more complex kidney patients with acute and chronic kidney diseases, with reduced budgets.