Figure 1: Swelling due to venous wall dissection in the brachiocephalic arteriovenous fistula.
Gray-scale and color Doppler ultrasonography (USG) revealed a thickening of the concentric vein wall (11.2 mm) extending along the arterialized cephalic vein up to its junction with the axillary vein (Figure 2). There was good flow in the vein lumen, but it was slightly narrowed. Cannulation of the vein was done from the proximal portion of the cephalic vein for subsequent hemodialysis because the fistula patency had been preserved. The patient received low-dose heparin at dialysis and no heparin during the hemodialysis-free intervals. The patient had an uneventful recovery, and one-month follow-up revealed a regression of the venous dilatation (Figure 3). Control USG revealed normal venous wall thickness (Figure 4).
Figure 3: Regression of the swelling after a month.
Figure 4: Ultrasound image demonstrating the normal cephalic vein wall after a month.
Vesely et al.[4] reported venous dissection in three cases, due to a venous percutaneous angioplasty procedure. Venous dissection is defined as a partial thickness tear with disruption of the intimal and medial layers of the vein wall in which the adventitial layer remains intact. Minor venous dissections may be ignored or unrecognized whereas major venous dissections may often be incorrectly categorized as venous ruptures. Venous dissection does not cause perivascular hemorrhage, but a flow-limiting dissection can decrease the efficiency or cause thrombosis of a vascular access. They can be managed using percutaneous techniques.[5] However, in our case and in one other reported incident, venous dissection regressed without any intervention.
Venous dissection appears to result from vein layer disruption caused by the misplacement of the bevel of the needle which leads to the formation of a layer gap through which an anterograde dissecting column originates. This is driven by the pressure of the dialysis machine’s blood pump. Additionally, the vein wall lesion may occur at the time of cannulation when the needle bevel is rotated.[3] Venous dissection, in our case, had occurred just after venous puncture before hemodialysis was started.
It is important to make the differential diagnosis from thrombosis which necessitates surgical revision. On the other hand, medical therapy is mostly sufficient for the patency of the fistula. Furthermore, as in our case, it may not be necessary to suspend hemodialysis if there is a good flow through the vein and if the length of the vein proximal to the dissection is enough for venous puncture.
In conclusion, venous dissection is a complication which is very rarely seen in vascular access for hemodialysis. It can be treated with supportive measures when diagnosed. We suggest routine dialysis from the proximal portion of the fistula if there is a good flow, which may be indicated by a good thrill.
Declaration of conflicting interests
The authors declared no conflicts of interest with respect
to the authorship and/or publication of this article.
Funding
The authors received no financial support for the
research and/or authorship of this article.
1) Woods JD, Turenne MN, Strawderman RL, Young EW,
Hirth RA, Port FK, et al. Vascular access survival among
incident hemodialysis patients in the United States. Am J
Kidney Dis 1997;30:50-7.
2) Hossny A. Brachiobasilic arteriovenous fistula: different
surgical techniques and their effects on fistula patency and
dialysis-related complications. J Vasc Surg 2003;37:821-6.
3) Salgado OJ, Chacón RE, Alcalá A, Alvarez G. Vein
wall dissection: a rare puncture-related complication of
brachiocephalic fistula. Gray-scale and color Doppler
sonographic findings. J Clin Ultrasound 2005;33:464-7.