Tunneled central venous catheters for dialysis - A necessary evil?

More than 65% of patients of chronic kidney disease (CKD) present as end-stage renal disease (ESRD) to a nephrologist in India, thus making it difficult for any systematic planning for ESRD care in stage IV of CKD.[1] Thus, except for a small number of patients who may have planned for ESRD care earlier, almost all ESRD patients require immediate/urgent dialysis, necessitating central venous catheterization for emergency vascular access. A significant number of these patients have severe acidosis, pulmonary edema, or fluid overload not allowing tunneled catheters as first choice but a temporary femoral catheterization for urgent dialysis and stabilization before a tunneled catheter can be placed.

The transition from nontunneled catheters to tunneled cuffed catheters is driven by “AVF first drive” in the Western World. Fistulae require a much longer maturation time varying from 4–8 weeks, and during this time a reliable vascular access for hemodialysis is provided by tunneled cuffed catheter.[2]

Sampathkumar et al. in their study in a recent issue of Indian Journal of Nephrology argue for a niche for tunneled central venous catheter (TVC) as vascular access in India.[3] However, catheter-related bacteremia (CRB) remains a common complication of TVC's. The relative risk of TVC's causing bacteremia in patients is approximately ten times higher than the risk of bacteremia in patients with AV fistula.[4] The risk of infection-related hospitalization/mortality is 2–3 fold higher with TVC's in comparison to AV fistula.[5]

The most important risk factor for bactremia with TVC's is prolonged duration of usage. The cumulative risk of CRB was 35% at 3 months and 48% at 6 months in one study.[6] Other risk factors for CRB are hypoalbuminemia iron overload, diabetes, immunosuppression, and recent surgery.[7]

Improvement in vascular outcomes is feasible. The fistula first breakthrough initiative (FFBI) reports that in prevalent US HD patients fistula use increased from 32% in 2003 to 55% in March 2010, arterio venous graft (AVG) use decreased from 40% to 21% and catheter use decreased from 27% to 24%.[8] However, in India, the tide of maintenance hemodialysis is just started. Vascular access has not been an important issue for Indian nephrologists until now. It is estimated that there are approximately 55 000 prevalent maintenance dialysis patients in India at present (personal communication – Fresenius market survey 2010). Dialysis units that have large number of maintenance dialysis patients have already started grappling with vascular access issue just as in the developed world. It is time for dialysis units and nephrology departments to set in motion protocols for optimal creation and care of vascular access.

It seems with the current clinical trends of nephrology practice in India, how much we might hate or love tunneled catheters; they have a role to play as a reliable and acceptable form of immediate, short term, and sometimes intermediate term vascular access in a large number of our patients who initiate dialysis. If they have to stay, one might as well accept them and develop practices and protocols if not to abrogate but at least to mitigate the complications related to TVC's especially those of CRB, thrombosis and associated morbidity and mortality.

The foremost amongst these are to insert catheters with maximal sterile barrier precautions. There is Grade I A evidence to recommend hand washing with antiseptic soap or alcohol-based gels, followed by sterile gloves, long-sleeved surgical gown, a surgical mask, and long sterile drape and 2% chlorohexidine for skin disinfection.[9] The insertion should preferably be done in an interventional suite with ultrasound and fluoroscopic facilities, but this may not be available to all.

K/DOQI guidelines suggest that incidence of CRB should be less than 10% at 3 months.[2] Each dialysis unit should have a written protocol describing in detail the proper use of aseptic technique of insertion, manipulation, and dressings applied after each dialysis. The technical staff handling the catheter needs to be adequately trained in these techniques. Compliance to sterile barrier techniques should be audited regularly to keep the infection rate under check. There is evidence that strict adherence to these protocols leads to decrease in the complications.[9]

One approach to decrease CRB has been to use topical antimicrobial at exit site. This approach reduces the incidence of bacteremia, as shown in a metaanalysis;[10] however, there is a real danger of emergence of serious resistant strains of bacteria.[11] Antimicrobial coating of hemodialysis catheters has also not been shown to be effective in reducing CRB in a systematic review evaluating 29 trials with 2886 patients and 3005 catheters.[12] Same trial however showed that antimicrobial locks with heparin were associated with decreased rates of CRB (OR 0.33, 95% CI 0.24 – 0.45). However, systemic toxicity and development of antibiotic resistant organisms is again a real concern.[12] Use of recombinant tissue plasminogen activator (rt PA) once a week with heparin has been shown to reduce the incidence of catheter malfunction and bacteremia.[13] Cost of such therapies would be inhibitory in Indian setting.

It would be a huge miss, if we along with setting up these protocols of maximal barrier practices for TVC's do not inculcate protocols for CKD education of our patients early in stage III and IV so that AV Fistulae are formed well in time to eliminate the need for catheters. Many might consider it to be a wishful thinking, but it is something worth to aspire for.