Vascular Access for Chronic Haemodialysis in Lombardy

Which Vascular Access for Chronic Hemodialysis in Uremic Elderly Patients?

The type of hemodialysis vascular access (fistula, graft, catheter) employed plays an important role in the results of dialysis treatment. Moreover, different complications can affect the vascular access and interfere with the morbidity and mortality of patients.

The ideal vascular access is the Cimino Brescia fistula. Graft and catheter methods should be considered as “second choice” because they present a higher incidence of complications, mainly due to thrombosis and infections. Finally, in elderly patients the vascular bed is frequently damaged and this may make it difficult to create a Cimino Brescia fistula.

In a 5-year period, 140 elderly patients (>65 years) and 63 “young” patients (< 65 years) started dialysis treatment in our facility. In the elderly group, a native fistula was created in 88% of cases, whereas in the younger patients the percentage was 94% (p: NS). The grafts were, respectively, 11% in elderly and 6% in young patients. Only in one case, in one elderly patient, was a permanent catheter the first vascular access.

We also report survival rate of the first vascular access, the incidence of thrombosis, and the need for creating another type of access.

We suggest that a native fistula can be easily created in elderly patients and a “second choice” access should be limited to a small proportion of patients.

Blood Flowrate and Dialysis Adequacy in Patients with Permanent Central Venous Catheters

Vascular access efficiency is a major determinant of an adequate dialytic treatment and reports from literature indicates a growing interest in the field of central venous catheterisation as permanent vascular access for hemodialysis. The main reasons are the continuous improvement in design and biomaterials along with the increased number of patients with failure of their vascular beds. In this paper it is presented and commented a series of negative crucial factors which can reduce the quality of the hemodialysis treatment: the problem of recirculation and the catheter related (and the patient related) causes of inadequate flowrate. Finally the Authors conclude with a short presentation of their clinical experience in the field.

Central Venous Catheter and the Hemodialysis Patient: A Difficult Symbiosis

In the last ten years, tunneled central venous catheters (pCVCs) have been increasingly utilized in chronic hemodialysis patients, sometimes in the place of fistulas. They have gained popularity for their unquestioned advantages, such as the possibility for immediate use. However, several problems have emerged following their diffusion. In this paper we review the main complications of pCVCs. Complications connected with insertion are generally due to an inaccurate approach to the vein. Ultrasonographic guidance has partially solved this problem and EC-ECG (endocavitary ECG) allows an accurate positioning of the tip. Infections, venous and/or pCVCs) thrombosis and dysfunctions are the most important catheter-related complications. Infections may occur with and without symptoms of systemic illness. Early diagnosis and appropriate antibiotic treatment are essential for saving the catheter. The pathogenesis of infections and strategies for prevention are discussed. Thrombosis and stenosis are well known complications of subclavian and jugular catheterization. In uremic patients, for temporary use, we suggest using the femoral position. Protocols for application of thrombolytic agents in pCVCs are considered. Dysfunction, defined as the failure to maintain a blood flow of at least 250 ml/min, remains the Achilles’ heel of the system. Adequate look therapy and tip position are only two basic aspects. In conclusion, a pessimistic outlook on the matter could lead us to consider that the advantages of catheter use are far outweighed by the disadvantages. However, we cannot avoid using central venous catheters in our dialysis units and a great challenge awaits both physicians and manufactures in the coming years.

Vascular access for chronic haemodialysis in elderly patients: the Lombardy experience

The growing proportion of elderly patients largely accounts for the striking increase in number of patients admitted to renal replacement treatment (RRT) in recent years. Most of them are treated with haemodialysis, which involves various problems connected with vascular access. A survey was therefore conducted amongst the Dialysis Units of Lombardy. The aim was to evaluate how vascular access surgery for elderly patients is or-ganized, and which techniques are used to monitor surgical access as well as the central catheters (CVCs). A questionnaire was sent to the 43 Lombardy Units, 79.1% of which replied. The results of a previous study analyzing the same topics in all patients on RRT in Lombardy were considered as 'controls'. In this way it was possible to compare the strategy used for elderly patients with that of the general dialysis population. Forty-one percent (41%) of elderly patients in Lombardy were started on RRT using acute CVCs. This percentage is quite similar to that documented (39%) in the general dialysis population. The distribution is quite dif-ferent when we consider the patients alive on RRT at 31 December 1999, when a permanent vascular access (distal AVF, proximal AVF or AV graft) was used in about 70% of cases. For elderly patients, as for the general RRT population, first choice access is mainly (79%) distal arterio-venous fistula (AVF) with end-to-end, side-to-side with distal ligature of the vein or side-to-end anastomosis. As a second choice, proximal AVF is more widely used than AV grafts, which are implanted only when all native vessels and related surgical procedures are exhausted. CVCs are valid solutions not only as temporary access, but also as an alternative permanent solution to the problems related to elderly dialysis patients. In the elderly, the jugular vein is the most frequent site of inser-tion for chronic tunnelled devices (91%) and the femoral vein for acute CVCs (40%). Despite the documented incidence of related episodes of stenosis/obstruction, the subclavian vein is used as a temporary access in quite a high percentage of cases (22% in the elderly and 32% in the general RRT population). Only in selected cases diagnostic procedures (mainly Venography and Doppler studies) are performed prior to permanent access choice. Similarly, vascular access is monitored mainly using a recirculation test, albeit not routinely. As in the general dialysis population, in the cases of vascular access thrombosis and stenosis, surgical re-vision is the most common approach.