Dialysis catheters play essential role in ESRD patients requiring dialysis for long period. Different types of dialysis catheters are used depending upon the patient’s need. It can be temporary or permanent (tunneled), depending on their purpose and usage time. Tunneled dialysis catheter enters the skin, courses approximately 6 to 10cm within subcutaneous tissue prior entering into the desired vein which reduces the risk of infection as compared to double lumen catheter which enters directly into the vein. TDCs have traditionally been placed by surgeons using palpation/anatomical landmark methods. In the last few years, there is an increased trend of placement of TDC by interventional radiologist due to their improved expertise and ability to handle complications .
The site of vascular access has significant influence on patient’s clinical outcomes. Various veins may be nominated for the TDC placement depending upon vein patency, however with repeated passage of catheter the vein gets thrombosed and stenosed . NKF-KDOQI states that RIJV is the ideal vascular access site due to its straight course with a single turn. LIJV, the external jugular veins, the femoral veins, the subclavian veins, transhepatic accesses, and translumbar accesses are further access alternatives in order of preference . In 5–18% of patients, there is anatomical variations of jugular veins, hence ultrasound guided puncture and fluoroscopic guided insertion results in considerably reduced unsuccessful attempts, hematoma formation and arterial puncture . During the study period, most of the patients received catheters in RIJV (87.7%) which is an established practice worldwide [18–20].
Tunneled cuffed catheters may be more suitable for medium to long-term usage where there is the expectation of a continuing need for renal transplant or arteriovenous fistula formation over weeks to months. In the present study, mean time to catheter removal due to malfunctioning was 557 (95% CI: 474 – 640.6) days. The mean duration of catheter use greatly varies among studies. Another Pakistani study reports a median catheter duration of 62.5 (IQR=46 – 89.5) days . Sampathkumar et al reported a median catheter usage of 213 days . Yalvac et al reports a relative a longer mean duration of 729.6±58.4 days for catheter use as compared to other studies . Mean catheter duration of 122 days was reported from Egypt . Forauer et al reported a mean catheter time for elderly and younger group was 137.4(range= 2–622) days and 139.7(range =1-944) days respectively . There may be many possible factors that caused variation in catheter usage time such as infection rate, different approaches for patient care and patients’ handling as well.
The progressively imperative TDC role for delivery of haemodialysis in inadequate resource settings in contrast to the AV fistula or graft use is of high concern and could be a causative factor to the compromised quality of life and adverse patients' outcomes. Catheters are accountable for half of the infections in hemodialysis patients, and catheter-related bloodstream infections (CRBSIs) are considered as the second most cause of expiry, also a chief cause of catheter removal and metastatic infection in hemodialysis population [24–26]. In our study, during one year period total 8.5% developed CRBSI which yielded an incidence rate of 5.01 per 10,000 catheter days. Another Pakistani study reported that 19.8% of patients developed CRBSI during the study period and catheter removal was required in 63.6% of these patients . A risk of 9% at one year was reported for bacteremia and 30% for any CVC related complication during first year follow-up . In contrast to our findings, an alarming infection rate was reported from India, the study documented that 30.4% patients had positive blood culture during six months follow-up after placement of TDC . Another study from Saudi Arab reported that CRBSI was 23.6% per year . The CRBSI incidence rate of 6 cases per 1000 catheter days was also reported from Egypt . Variation in infection rate among different studies could be due to multiple causes, mainly because of differed health settings and patients’ attitude. Previously conducted studies reported that risk of CRBSI was significantly higher among patients with catheter placement from left internal jugular vein, diabetes, increasing catheter duration [31, 32]. However, in the current study no significant association of any factor was determined with CRI.
In the present study, majority of the catheters were electively removed (72.3%) as the patients were dead, gained permanent access through fistula formation or they had no further need of dialysis and remaining were non-functional at the time of removal which were removed due to complications including infection, blockage and physical damage. In contrast to our findings, a study from Turkey reported that TDCs were electively removed in nearly one third of the patients (31.1%) . Forauer et al demonstrated that 28% catheters were electively removed due to functioning AV access, renal transplantation, conversion to peritoneal dialysis, or return of adequate renal function . A similar study from India reported that during three years period total 45% catheters of which majority were electively removed due to death with functioning catheter, switch to AVF and renal transplant . Increasing age and diabetes were documented as independent factors negatively affecting catheter patency but our data did not suggest any such association [21, 33].
The current study shed light on the experience of a single center tertiary care hospital regarding the TDC patency. The results cannot be generalizable to all of the Pakistani patients receiving TDC as it is single center experience study. It is quite difficult to make comparisons for various institutes owing to the differences in placement methods, catheter types and patients’ features. However, these factors may be minimized in terms of negatively affecting patients’ outcomes with a highly experienced multi-disciplinary team.