Central venous stenosis and methods of its treatment in hemodialysis patients

Abstract

There is no doubt that the optimal vascular access is arteriovenous fistula (AVF). However, the proportion of patients receiving hemodialysis using central venous catheters is very high. Largely due to this, the incidence of central venous stenosis (CVS) in this category of patients is one of the highest: the prevalence ranges from 2 to 40%. Against the background of functioning AVF from the ipsilateral side, CVS proceeds with much more pronounced symptoms than in the general population of patients with this pathology. There is no doubt that stenosis of the central veins is a precursor of AVF thrombosis, recurrent infections, reduction of blood flow in the limb in general and AVF in particular, and consequently - increase in recirculation and decrease in the effectiveness of HD. Endovascular surgery is the «gold standard» treatment for CVS. Technical success is at least 80-90% of the cases. As a rule, endovascular operations not only lead to the immediate reduction of symptoms of venous hypertension, but also allow the use of fistulas for hemodialysis in the near future after the intervention. At the same time, clinical success is achieved much less frequently. Primary patency in six months is about 50%, secondary patency in two years - 60-80%. The use of cutting balloon catheters may be associated with greater secondary patency than using standard balloon catheters, but slightly increases the risk of complications. An effective way to improve the results of CVS plastic is the use of stents, which allow to increase the patency after surgery. Indications for the primary use of stents is a debatable issue. However, stenting is undoubtedly effective in the case of rapid occurrence of recurrent stenosis or rigid stenosis and recoil immediately after surgery. In addition, one of the problems associated with the use of stents is the risk of their migration. This risk increases in patients with functioning AVF. Skepticism about the use of stents in patients on hemodialysis is also added by the fact that in randomized controlled studies, when comparing isolated balloon angioplasty and angioplasty using uncovered stents, there was no significant difference in the recurrence of stenosis. At the same time, the use of covered stents provides a significant increase in access survival. In addition, the use of drug-coated balloon catheters may provide some advantage over standard uncoated balloon catheters. Open surgical interventions have slightly better results in the treatment of CVS (annual primary patency of 80-90%) compared to endovascular methods. Nevertheless, open reconstructions are associated with a much greater risk of intra- and postoperative complications, in most cases require clavicle section or sternotomy, general anesthesia, and are associated with greater postoperative mortality. In this regard, percutaneous transluminal angioplasty is deservedly considered to be a common method of treatment of CVS. Open surgery can be used in case of unsuccessful attempts to resolve stenosis endovascular while maintaining a pronounced clinical symptoms. On the face of the fact that the available methods of treatment of this pathology in patients on hemodialysis with functioning vascular access do not fully meet the clinical needs. Currently, there is no consensus on many aspects of the use of endovascular interventions for the correction of vascular access dysfunction, which requires additional research.