A traumatic arteriovenous fistula in Hunter’s canal

The patient turns to the vascular surgery for pain and ulceration in the lower right limb. History reports an old gunshot wound. Clinical tests show signs of venous hypertension. The Color-Doppler exam demonstrates increased and pulsating flow to the common femoral vein (CFV) and the superficial femoral vein (SFV).

The CT was performed with contrast agent in the arterial and venous phase. In the arterial phase, early venous opacification in the inguinal and right lower limbs is detected, as typical of the pathology (Fig.1). A wide communication (17 mm) between the superficial femoral artery (SFA) and SFV is visualised in the adductor canal (Fig. 3-4), with associated marked dilatation of the venous circle and its collaterals (Fig. 2-3). A small pseudoaneurysm at the level of the fistula is clearly visible in the volume rendering reconstructions (Fig. 3). The angiographic examination shows a rapid and early passage of nearly all the contrast agent in the SFV and its collaterals (Fig. 5). The right common femoral artery (CFA) was accessed and two Viabhan (W. L. Gore & Associates, Flagstaff, Arizona, USA) imbricated endoprostheses (10 x 100 and 11x 100) were placed in the superficial femoral artery to exclude the fistula (Fig. 6). After positioning the stents, the control performed showed good opacification of the SFA with complete exclusion of the fistula (Fig. 7).

Arteriovenous fistula is a condition of abnormal communication between an artery and a vein, the first cases were described in the 18th century (Hunter, Guattini, Scarpa) [1]. This condition can be created intentionally to allow access to hemodialysis or it can be an expression of a congenital or acquired pathology. Post-traumatic causes are well known among the acquired causes of arteriovenous fistulas, the most frequent are currently those of iatrogenic origin [2], but numerous cases of gunshot injury have been described in the literature.

These lesions can remain unknown for many years [3-4] and progressively create conditions ranging from venous hypertension to heart failure [5]. When properly framed clinically and with the aid of the investigation with Color-Doppler, diagnostics is entrusted to the CT with contrast medium, which is a fundamental examination to confirm vascular lesions [6-7]. CT can easily demonstrate the location and extent of the fistula, collateral circles, associated lesions as pseudoaneurysm [8] and helps in deciding the best therapeutic approach.

Arteriovenous fistulas can be treated with a surgical, non-surgical or with a combined approach. Nonsurgical treatment options include compression therapy, endoprosthesis placement, coil embolisation, percutaneous collagen and thrombin injection [9]. Already in the 80s / 90s [10-11] the possibility of treating vascular lesions with stents is known, with the improvement of techniques and materials, this is the currently preferred option [9] the long-term results of endovascular treatment are indeed comforting [12].

In relation to the location of the lesion, endovascular treatment was preferred to the classical surgical approach, as already reported in the literature [13]: for the lower percentage of complications and for a predictable faster functional recovery. A few hours after the operation, the patient reported the improvement of the algic symptoms and after a few days, there was rapid healing of ulcerative leg lesions (Fig.8). CT with contrast medium is the essential examination for the correct clinical framework and for therapeutic planning of vascular lesions. Whenever possible, treatment of arteriovenous fistulas with endovascular stents is a quick and safe system.

Written informed consent was obtained from the patient to anonymously publication of clinical material.