ANZ Journal of Surgery | 2019
Suprascapular artery pseudoaneurysm
Abstract
An 80-year-old woman presented with several days of severe left shoulder and back pain, associated with a tender supraclavicular swelling. She had no recent trauma but had sustained left sided scapular and clavicular fractures following a fall 2 years prior. She had been on rivaroxiban for the preceding 5 months for a left arm deep vein thrombosis, likely secondary to hypertropic non-union of her clavicular fracture. She was a non-smoker with no history of ischaemic heart disease, hypertension, diabetes, respiratory or cerebrovascular disease. Examination revealed a swollen left arm with bruising over her back. Upper limb pulses were palpable but there was a very tense swelling in the posterior aspect of left supraclavicular fossa, with a softer area of swelling anteriorly. Her vital signs were within normal limits and blood tests, including full blood count, were unremarkable. Duplex ultrasound performed by a dedicated vascular sonographer identified an occluded left subclavian vein and appearances consistent with a soft tissue haematoma but did not show any arterial abnormality. An arterial phase computed tomography angiogram (CTA) subsequently demonstrated a pseudoaneurysm, approximately 8 mm in diameter, arising from the suprascapular artery (Fig. 1a). A three-dimensional CTA reconstruction is shown in Figure 2. The CTA also showed the short occlusion of the left subclavian vein was well collateralized. An angiogram was performed via a transfemoral approach to allow more direct in-line access to the suprascapular artery in anticipation that selective catheterization and coil embolization of the pseudoaneurysm would be required. However, this demonstrated a small knot of vessels in the location of the pseudoaneurysm but no active extravasation (Fig. 3) and therefore no intervention was performed. As anticoagulation had been ceased 48 h prior, this interval may have been sufficient to allow thrombosis of the pseudoaneurysm. As there was no active extravasation, the decision was made not to pursue microcatheterization of the suprascapular artery. As the pseudoaneurysm was both small and technically difficult to access, with no active extravasation, the consensus was to stop her anticoagulation and monitor her clinical course. Within 48 h her pain had settled, with no further extension of the haematoma. The patient experience significant discomfort during ultrasound scanning and so a follow-up CTA was arranged (Fig. 1b). This was performed after 12 days and demonstrated significant resolution of the pseudoaneurysm, with stable surrounding haematoma. CTA also demonstrated a well collateralized left subclavian vein and a decision was made to permanently stop anticoagulation, with the balance of risk for recurrent venous thrombosis without anticoagulation versus bleeding felt to be in favour of cessation. No further imaging was arranged and she will be followed up clinically. Pseudoaneurysms of the suprascapular artery are uncommon, but may occur following iatrogenic injury, trauma, thoracic outlet syndrome or develop from an anomalous origin. The suprascapular artery most commonly arises from the thyrocervical trunk and runs deep to the clavicle before entering the supraspinatus fossa of the scapula. The artery remains closely related to the scapula as it descends to anastomose with the scapular circumflex artery and