COMPARISON OF COMPLICATIONS AND DIALYSIS ADEQUACY BETWEEN TEMPORARY AND PERMANENT TUNNELLED CATHETER FOR HAEMODIALYSIS

Number of hemodialysis patients each day is increasing. Th e quality of their lives is largely determined by the quality of hemodialysis treatment. One of the most important factors is the type of applied blood approach. Th e type of blood approach in the most case is artery venous fi stula, permanent, temporary catheters, grafts. Any complications of blood strand approach inevitably leads to lower quality of hemodialysis treatment which is connected with not adequate dialysis and poorer general state of patients. Our research was carried out as a prospective study, for the period of  months. In the study were included  patients, which are on chronic haemodialysis treatment. During this study, we are followed all complications, which occurred at temporary, and permanent tunneled haemodialysis catheters. Complications have occurred in terms of thrombotic problems, low blood fl ow, occurrence of infection. All patients are divided in two groups,  patients with permanent and  patients with temporary catheters. In the course of the study was analyzed blood fl ow and dialysis adequacy (Kt/Vdp) as well as complications and results was compared with randomly selected  patients who haemodialysis treatment performed by artery venous fi stula (AVF). Two patients were lost to further follow-up to the end of the study.  patients at the end of the study had functional catheters, while in the case of  patients the catheter was removed. Infection was found in  patients while thrombotic complications were observed in  cases regardless of catheter type. Mean blood fl ow in patients with permanent catheter was signifi cantly higher (,±, cm/min) compared to patients with temporary catheter (,±, cm/min) (p<,). Kt/Vdp delivered was ,±, on patients with permanent catheter and ,±, for artery venous fi stula (AVF) access respectively. Th e loss of dialysis effi cacy using catheters was estimated at . However, in all cases Kt/Vdp values remained above the recommended values (Kt/Vdp ≥ ,).


Introduction
Tunnelled permanent catheters are increasingly used as a permanent vascular access on haemodialysis (HD) patients.Th e use of tunnelled catheters for vascular access for hemodialysis is associated with a relatively high incidence of complications.The most frequently occurring complication is catheter dysfunction or poor blood fl ow (, ).Catheter dysfunction may be classifi ed as early or late ().Th is time distinction is important because the aetiology for the problems that result in these two categories is diff erent.Early catheter failure is defi ned as that which occurs immediately.In other words, the catheter never functioned adequately (i.e., did not deliver the expected blood fl ow of ≥ mL/ min).Late dysfunction is defined as a catheter that initially functioned in an optimal fashion, but then became dysfunctional.Such difficulties are usually due to thrombosis.Hemodialysis catheters are frequently complicated also by dysfunction from fi brin sheaths.A randomized, controlled, pilot trial was conducted to investigate the impact of angioplasty sheath disruption on catheter patency and function.In that study was analyzed forty-seven long-term hemodialysis patients with secondary, refractory catheter dysfunction underwent guide-wire exchange to replace their catheters ().According to the United States Renal Data System (USRDS) data,  of all haemodialysis patients perform their treatment directly via permanent tunnelled catheter (), while the number in Europe is slightly smaller, namely -.According to recent guidelines, developed by Th e National Kidney Foundation Disease Outcomes Quality Initiative (NKF-KDOQI)™ (), the usage of tunnelled permanent catheters should be limited to no more than  of patients of the total number of haemodialysis patients.Introduction of these catheters has become more popular in the Eastern Europe countries in the past  years.Th ese catheters are used for patients who have exhausted all possibilities for the design of AV fi stula (), or as solution for vascular access for those patients who are waiting on the maturation of AV fi stula to be actively used (, ).In order to improve functionality and eliminate late dysfunction of a permanent catheter until now some studies have analyzed different methods where double lumen dialysis catheters are routinely treated by heparin or citrate 'locked' to maintain patency.In conclusion of that study all double lumen dialysis catheters, have a substantial amount of leak even when the catheter 'lock' volumes were used, and leak ratio increases signifi cantly with  overfi ll ().In our institution the usage of tunnelled catheters, as a form of permanent access for haemodialysis treatment, began in June  for those patients who had exhausted other options for vascular access.Introduction of these new techniques for the treatment of patients with end-stages renal disease give the required implementation and additional measures of care, prevent the appearance of infections, provide new methods of access and placement and ensure adequate conditions in which to place the permanent catheters ().Th us the attention and monitoring of patients with this new kind of vascular approach has increased.Th e design and venous location of catheter devices bear intrinsic fl ow limitations that may negatively aff ect the adequacy of dialysis and the patient outcome (, ).Th ere is limited data comparing the long-term dialysis adequacy delivered with permanent catheters vs. temporary catheters compared with artery-venous vascular access (AVA).

Aim
The aim of this study was to assess complications of temporary versus permanent haemodialysis catheters during the monitoring period of last  months and to evaluate dialysis adequacy in patients with temporary and permanent tunnelled catheter compared to patients with artery-venous vascular access.

Patients and Methods
Th irty-one patients with end stage renal disease (ESRD) starting HD in our dialysis unit without functional or usable AVA were enrolled in this study at the Clinics Centre University of Sarajevo.All patients were informed and signed consent was obtained.Th erefore,  patients completed the -month comparative study:  males with the mean age ±, years and  females with the mean age ±, years.Out of  patients with catheters there were  patients with permanent catheter (mean age ,±, years);  males and  females.Th ere were  patients with temporary catheters (mean age ,±, years);  males and  females. patients had diabetes mellitus type .Causal nephropathies were as follows: primary chronic glomerulonephritis, ; hypertensive and vascular nephropathies, ; diabetes type II, ; polycystic kidney disease, ; and systemic disease and miscellaneous, .Residual renal kidney function (RRF) was calculated every month based on mean urea and creatinine clearances obtained from a  h urea collection.To explore this problem, we conducted a prospective -month study comparing the flow performances and dialysis dose NIHAD KUKAVICA ET AL.: COMPARISON OF COMPLICATIONS AND DIALYSIS ADEQUACY BETWEEN TEMPORARY AND PERMANENT TUNNELLED CATHETER FOR HAEMODIALYSIS (Kt/Vdp) deliveries of both access options in a group of  haemodialysis patients during the study.During the period of  months the patients completed a treatment period by means of permanent dual silicone catheters (which made the company Medcomp, models Splithcath II and Duoflow).Then they compared with a  patients that already have constructed native artery-venous fistula (AVF) and monitored for a -month period.Assessments of flow adequacy and dialysis quantification were performed monthly.
The average length duration of haemodialysis was ,±,.Th e average length duration of temporary catheters was ,±, months and average length duration of permanent catheters was ,±, months.

Inclusion criteria:
-patients on haemodialysis treatment longer than three months -patients with permanent catheter previously exhausted all other options for vascular access -International Normalized Ratio (INR) and Activated Partial Thromboplastin Time (APTT) must be in the reference values before placement of permanent catheter -no systemic disease that infl uence blood coagulation Exclusion criteria -Kidney transplantation -Transferred of the patients to other dialysis unit -Artery-venous fistula (AVF) created and used before the end of the fi rst three months -Diff erent facilities (lost for follow-up) -Lethal outcome All patients, to whom the permanent tunnelled dual lumen catheter had been placed, have been submitted to Colour Doppler procedure.Firstly we took in the consideration possibility of the construction of AV fi stula.Th e next step was to look for professional opinion of vascular surgeon regarding the patients with whom the possibility of construction of artery-venous fistula did not exist. patients were alive at the end of the period of observation, of which  of them with a functional catheter.At  patients the catheter had to be explanted due to newly created AV fistula.From  patients included in this study  patients have died.All other patients from the study had fully functional catheter.At the end of the period of monitoring of patients in our dialysis centre there were  patients who performed dialysis treatment through double lumen tunnelled catheters, from a total number of  patients.An infection was performed by removing the existing catheter and placing a new catheter with a creation completely new tunnel.Infections at the strain catheter were treated with broad spectra antibiotics.

Catheters placement
 dual lumen haemodialysis catheters were implanted in  haemodialysis patients who were on chronic haemodialysis treatment for a period longer than  months. polyurethanes and  silicones dual lumen access permanent catheters were used.Most commonly used permanent catheters which made the company Medcomp, Splithcath II and Duoflow type.All catheters were introduced using a split-sheath technique.Permanent catheters were placed in the right internal jugular vein.Th is approach was not possible in fi ve cases; access through the subclavia veins was necessary in one case, in the case of  patients access was made via the left internal jugular vein and in one case catheter is placed in right femoral vein.Post-procedural radiological control was used instead of fl uoroscopy during the process of introducing catheters. of  patients were lost to follow-up; the most common reason was the departure of patients to other dialysis centre.Prior to the placement of a catheter to all patients was taken a detailed medical history (family, epidemiological, morbid condition), also to all patients at least once a month and made dialysisambulance, which includes ECG, X-ray of the lungs, and detailed examination by a doctor of internal disease.Th ey also take into account previous attempts and the number of diff erent attempts of vascular access, as well as regular monitoring of therapy necessary for these patients.In patients who are on chronic hemodialysis program, it is necessary to regularly monitor the value of blood, urea and creatinine, calcium, phosphorus and potassium, the adequacy of dialysis treatment Kt/V carried out.In each catheter at the end of dialysis must include an anticoagulant to preserve the functionality of a catheter.Anticoagulant drugs are given in the course of dialysis treatment for the prevention of blood clotting during hemodialysis.Usually given standard heparin and low weight molecular heparin (LWMH).Th erefore, for all patients is monitored value of INR and APTT.

Statistical analysis
Statistical analysis was performed using SPSS statistical software system (version ., SPSS Inc, Chicago, Illinois, USA).Values are expressed as mean ± SD.Significant differences between continuous variables were tested using Mann-Whitney's test and Chi-square test for categorical variables.Two-tailed p values <,  were considered statistically significant.At the end of study period  patients died, both with a functional permanent catheter and the mortality rate was ,.During the period of monitoring infection was detected in  subjects.In  subjects infection occurred around the tunnel of permanent catheter, in  patients infection occurred inside the tunnel, while in  patient infection was present at the output site of the catheter.Mean blood flow in patients with permanent catheter was significantly higher (, ± , cm  /min) compared to patients with temporary catheter (,±, cm  /min) (p<,).Significant difference was observed in blood flow rates in patients with permanent compared to tem-porary catheter.Higher blood flow rate (≥  / min) was observed more frequently in patients with permanent (n=) compared to patients with temporary catheter (n=)(χ=,; p<,)(Table ).Thrombotic complications were observed in  patients with temporary and permanent catheters.In patients with temporary catheter there were  catheter replacements while only  were needed for patients with permanent catheter (Table ).
Th e blood fl ow resistance of the Dual KT was slightly higher than with AVA as indicated by venous pressure differences.Kt/Vdp delivered was ,±, and ,±, with Dual KT and AVA access respectively (Table ).Th e loss of dialysis effi cacy using catheters was estimated at .However, in all cases Kt/ Vdp values remained above the recommended values (Kt/Vdp ≥ ,).Protein nutritional state, as well as conventional clinical and biochemical markers of dialysis adequacy, remained in the optimal range.

Discussion
According to data from the Renal Register of Bosnia and Herzegovina, more than  of patients on haemodialysis are older than  years of age ().Th e minimum percentage of the male part of respondents is aged between  and  years.Most male and female respondents are under haemodialysis treatment since .Th e analysis of our results indicates that the number of female patients with a temporary catheter is greater than the number of male patients ( compared to ).Th e reason for this is because the maturation of AV fi stula in female patients takes a longer period, which can be found in diff erent studies (). of our haemodialysis population have placed permanent catheter that is in accordance with the literature ().Th e same percentages of use of such vascular approaches have been reported and in other major studies so far conducted ().
In our study mortality rate of , during the  months was observed which is lower then mortality rate of  registered in the other countries (, , ).Th e morbidity and mortality in patients with permanent tunnelled haemodialysis catheter according to reports from other studies is greater than in the general dialysis population ().A recent analysis from Australia and from New Zealand published in Dialysis Transplant Association Registry shows a signifi cantly higher mortality rate for new dialysis patients who begin treatment through haemodialysis catheter or artery venous graft than in those patients who are at the beginning of treatment had designed AV-fi stula ().In the second study, among patients from the United States, found that mortality was higher in both groups, and in patients who have dialysis performed by the central venous catheter or artery venous graft compared with the A V-fi stula ().Th e possible reasons for our lower mortality rates compared to other countries could be due to the facts that our data refers only the prevalence, not incidence of haemodialysis patients with permanent and tempo-rary catheters ().Th e reason for this increased rate of mortality could be caused by specific complications of permanent tunnelled catheters, namely, infections and thrombosis.In our study nine cases with partial thrombosis and two cases with complete thrombosis have been observed, out of which  catheters were explanted.Most often the way the placement of tunnelled permanent catheters is in the right jugular vein (, ).In our study, the right jugular vein was used for placement catheters at  of male respondents, while for  of them the catheter was placed in the left jugular vein ().Th e catheter is the placed in the right jugular vein at  of female respondents, while  of catheters were placed in the left jugular vein.The analysis of blood flow in patients on haemodialysis with both sexes usually starts at the borders between - ml/min in  of men and in  of women.In our group of respondents all thrombotic complications were present in the case of diabetic patients.Th e relationship between men and women was  to ., which was confi rmed by Colour Doppler ultrasound.From the total number of patients, diabetes type I and II is present in cases of  male and  female patients.According to data from the literature, diabetes mellitus is one of the risk factors not functional of AV fi stula, which is also confi rmed in our study ().Th e infection is one of the most common complications that are present in permanent catheters and which are placed right behind thrombotic complication ().With respect to the application of adequate preventive measures to preserve the catheter, one patient had fever and then the catheter was removed for a period of two days, after which it was placed again, but on the opposite side, in left jugular vein.Our observations and the results that we have are related to the group of patients with very small rate of transplantations and with a very long of duration of haemodialysis treatment.Th erefore, the care about catheter-related complications such as infection and thrombosis was done quickly and adequately

Conclusion
Lifetime and co morbidity states are determined which of type vascular approach will be used for haemodialysis patients.In patients who have exhausted all other options for vascular access, the use of permanent catheters is more than welcome to conduct adequate hemodialysis treatment.In some patients which have expressed hyper coagulation and complications often occur in terms of thrombosis should consider other types of dialysis treatment.Permanent catheter show higher blood fl ow rate then temporary catheter.Application of permanent tunnelled catheter is a very useful alternative for the treatment of all patients who need haemodialysis and in those patients who are for various reasons cannot construct artery venous fi stula or any other kind of vascular access.
NIHAD KUKAVICA ET AL.: COMPARISON OF COMPLICATIONS AND DIALYSIS ADEQUACY BETWEEN TEMPORARY AND PERMANENT TUNNELLED CATHETER FOR HAEMODIALYSIS Results Age group of patients included in our study is shown on Figure .No significant difference in patient's distribution among age groups was observed.

TABLE 2 .
Comparison of thrombotic complications and a number of catheter replacement in patients with placed temporary and implanted permanent tunnelled catheters in diff erent blood vessels.
TC-number of thrombotic complications; CR-number of catheter replacement  BOSNIAN JOURNAL OF BASIC MEDICAL SCIENCES 2009; 9 (4): 269-270 NIHAD KUKAVICA ET AL.: COMPARISON OF COMPLICATIONS AND DIALYSIS ADEQUACY BETWEEN TEMPORARY AND PERMANENT TUNNELLED CATHETER FOR HAEMODIALYSIS