Long-Term Tunneled Hemodialysis Catheters: Achieving Efficiency Through Tip Position Optimization

BACKGROUND

This retrospective study assesses the influence of tunneled hemodialysis catheter tip location and lateralization on catheter-related complications, including dysfunction and catheter-related bloodstream infection.

METHODS

Using data from 162 patients who underwent catheter placement between January 2017 and December 2020, postoperative chest X-rays and clinical records were reviewed. Outcomes were assessed based on catheter removal duration and complication incidence.

RESULTS

Out of 177 catheter placements, 56 (32%) patients experienced complications during an average 530-day follow-up. Catheters placed in the superior vena cava (SVC) exhibited more severe complications with shorter dwell times compared with those in the pericavoatrial junction (pCAJ) or right atrium (RA). Moreover, complication rates were significantly higher (P < 0.01) in the SVC (1.91 per 1000 catheter days) compared with the pCAJ (0.54) or RA (0.47). Lateralization (right or left internal jugular vein) did not significantly affect the complication rates (0.60 vs. 0.58; P = 0.90). However, in subgroup analysis, a significantly higher complication rate was observed for catheters with tips inserted from the left side into the SVC than for those inserted from the right side (6.6 vs. 1.5; P < 0.01).

CONCLUSIONS

Catheters with tips in the SVC exhibited more severe complications than those in the pCAJ or RA, with left-side insertion of SVC-tipped catheters resulting in significantly higher complication rates compared with right-side insertion. These findings highlight the importance of optimal catheter tip positioning in long-term hemodialysis care to minimize complications and enhance patient outcomes.

Deeper may not be better: relationship between catheter dysfunction and location of the catheter tip in right-sided tunnelled haemodialysis catheters

AIM

To examine the relationship between catheter tip location and catheter dysfunction in the context of tunnelled central venous catheters (CVCs) for haemodialysis.

MATERIALS AND METHODS

This was a retrospective study of 993 haemodialysis patients who underwent insertion of tunnelled CVCs of step-tip design via the right internal jugular vein (IJV). Based on intra-procedural radiographs, the catheter tip was characterised as being in the superior vena cava (SVC), cavo-atrial junction (CAJ), or deep right atrium (DRA). Patients were tracked for 90 days post-procedure for complications resulting in catheter replacement, and these were compared between cohorts. Statistical analysis was performed with Pearson's chi-square and Fisher's exact tests for categorical variables and two-sample t-test and one-way analysis of variance (ANOVA) for continuous variables.

RESULTS

Ninety-five patients (9.6%) experienced catheter dysfunction necessitating replacement within 90 days of insertion. Tip location in SVC was associated with lower occurrence of catheter dysfunction (1.9%) as compared with the CAJ (8%) and DRA (11%; p=0.049). Catheter replacement due to other complications (catheter-associated bacteraemia, cuff dislodgement, exit-site infection, external catheter damage) showed no statistically significant relation to location of the CVC tip.

CONCLUSION

When utilising tunnelled CVCs with a step-tip design inserted via the right IJV, location of the catheter tip in the SVC is associated with reduced occurrence of catheter dysfunction as compared to either the CAJ or DRA.

The impact of anatomical variables on haemodialysis tunnelled catheter replacement without fluoroscopy

AIM

Tunnelled haemodialysis (HD) catheters can be used instantly, but there are several anatomical variables that could impact it survival. This study aimed to examine the impact of different novel anatomic variables, with catheter replacement.

METHODS

In a single-centre a prospective cohort in chronic kidney disease G5 patients were conducted. The primary outcome was to determine the factors associated with catheter replacement during the first 6-month of follow-up. All procedures were performed without fluoroscopy. Three anatomic regions for catheter tip position were established: considered as superior vena cava (SVC), cavo-atrial junction (CAJ) and mid-to deep atrium (MDA). Many other anatomical variables were measured. Catheter-related bloodstream infection was also included.

RESULTS

Between January 2019 and January 2020 a total of 75 patients with tunnelled catheter insertion were analysed. Catheter replacement at 6-month occur in 10 (13.3%) patients. By multivariate analysis, the incorrect catheter tip position (SVC) (OR 1.23, 95% CI 1.07-1.42, p <.004), the presence of extrasystoles during the procedure (OR 0.88, 95% CI 0.78-0.98, p = .03), incorrect catheter tug (OR 1.31, 95% CI 1.10-1.55, p = .003), incorrect catheter top position (kinking; OR 1.40, 95% CI 1.04-1.88, p = .02) and catheter-related bloodstream infection (OR 2.60, 95% CI 2.09-3.25, p <.001) were the only variables associated with catheter replacement at 6-month follow-up.

CONCLUSION

The risk of catheter replacement at 6-month follow-up could be attenuated by avoiding incorrect catheter tug and top position, and by placing the vascular catheter tip in the CAJ and MDA.

Influence of Hemodialysis Catheter Insertion on Hemodynamics in the Central Veins

Central venous catheter (CVC) related thrombosis is a major cause of CVC dysfunction in patients under hemodialysis. The aim of our study was to investigate the impact of CVC insertion on hemodynamics in the central veins and to examine the changes in hemodynamic environments that may be related to thrombus formation due to the implantation of CVC. Patient-specific models of the central veins with and without CVC were reconstructed based on computed tomography images. Flow patterns in the veins were numerically simulated to obtain hemodynamic parameters such as time-averaged wall shear stress (TAWSS), oscillating shear index (OSI), relative residence time (RRT), and normalized transverse wall shear stress (transWSS) under pulsatile flow. The non-Newtonian effects of blood flow were also analyzed using the Casson model. The insertion of CVC caused significant changes in the hemodynamic environment in the central veins. A greater disturbance and increase of velocity were observed in the central veins after the insertion of CVC. As a result, TAWSS and transWSS were markedly increased, but most parts of OSI and RRT decreased. Newtonian assumption of blood flow would overestimate the increase in TAWSS after CVC insertion. High wall shear stress (WSS) and flow disturbance, especially the multidirectionality of the flow, induced by the CVC may be a key factor in initiating thrombosis after CVC insertion. Accordingly, approaches to decrease the flow disturbance during CVC insertion may help restrain the occurrence of thrombosis. More case studies with pre-operative and postoperative modeling and clinical follow-up need to be performed to verify these findings. Non-Newtonian blood flow assumption is recommended in computational fluid dynamics (CFD) simulations of veins with CVCs.