Substantiation of a Venous Approach in Endovascular Neurosurgery and Initial Results of Its Clinical Application

S.B. Yakovlev, A.V. Bocharov, E.Yu. Bukharin, S.R. Arustamyan

Burdenko Research Institute of Neurosurgery, Russian Academy of Medical Science, Moscow, Russia

 

Today studying physiology and pathophysiology of a cerebral venous system is paid more and more attention to. Problems of normal anatomy are described in literature rather well. As for anatomy and physiology of venous circulation under conditions of pathology, they demand more profound study. Medical literature contains description of only single cases or small series of patients, who underwent venous occlusion and embolization.

Materials and Methods. A venous endovascular approach was used in 13 patients with different vascular pathology, treated at the Burdenko Research Institute of Neurosurgery in 2002-2004. The age of patients varied from 1.3 up to 67 years. Distribution of clinical entities was as follows: direct carotid-cavernous anastomoses - 36 cases; dural arteriovenous fistulas, located in the cavernous sinus - 4 cases, in the sigmoid sinus area - 2 cases, at the base of the middle cranial fossa - 1 case; malformations of vena magna cerebri - 2 cases and hemangioma - 1 patient.

Vasco 10, 14, 18 microcatheters (Balt, France) were used for catheterization of cerebral veins and sinuses. Occlusion of venous collectors was performed with MDS microspirals (Balt, France), having a coil diameter of 3-21 mm, and BAL 2-3 latex balloons (Balt, France). Interventions were performed with applying neuroleptanalgesia and systemic heparinization. We elaborated an algorithm for navigation within veins and sinuses. Road mapping operation mode of the Axiom Artis BA (Siemens) angiographic device was used.

Results. We met with surgical difficulties in all cases. They were conditioned by impossibility of performing an arterial approach or its limited character. Decision on using a venous approach in 6 cases was made after several stages of transarterial embolization, which turned out to be almost ineffective. As for the rest patients, we decided to use transvenous occlusion before operation. A transfemoral venous approach was performed in 12 cases; an open approach through a facial vein ensured catheterization and occlusion of the cavernous sinus in 1 case. Complete exclusion of a pathologic arteriovenous shunt with a good clinical effect was achieved in 11 patients. It was confirmed by angiographic examination. Considerable reduction of pathologic blood flow was obtained in 2 cases. There were no complications.

Dural arteriovenous fistulas were the most spread pathology. Blood supply had a multi-channel character with involvement of dural branches of extra- and intracranial vessels in all cases. Endovasal treatment of this pathology is considered to be the most difficult problem. Aggressiveness of a clinical course is conditioned by retrograde venous drainage. However, we want to emphasize high efficacy of a venous approach just in this pathology.

It should be noted, that navigation within cerebral veins and sinuses is extremely difficult and choosing a place of occlusion is a crucial point, which effects an outcome and results of treatment. Thus, planning of such interventions should be based on detailed study of architectonics of a pathologic arteriovenous shunt with estimation of possibility of blood flow compensation while making decision on occlusion of this or that venous collector.

The goal of endovasal intervention with using a venous approach is occlusion of a venous collector in close vicinity of an arteriovenous shunt, which will not result in disorders of normal cerebral venous hemodynamics.

We managed to probe and master main ways of catheterization of big cerebral venous collectors, as well to develop methods of performing endovasal interventions with use of an endovascular venous approach.

Conclusions

  1. Methods of catheterization and occlusion of cerebral venous collectors demand further development and improvement both for wider use in clinical practice and more detailed study of cerebral hemodynamics in normal and pathologic states.
  2. Initial clinical results are indicative of high efficacy of venous occlusion in treatment of complicated dural arteriovenous fistulas.