Transulnar Arterial Access During Prone Intra-operative Cerebral Angiography

Introduction: Recent literature has identified transradial artery access as non-inferior to transfemoral artery access, with additional advantages such as patient comfort and earlier post-procedural ambulation. During prone craniotomies for posterior fossa, occipital or parietal vascular lesions, intra-operative cerebral angiogram poses unique challenges given lack of access to the groin and radial artery being obscured given hand position while prone; in these cases, transulnar access (TUA) can be used as the primary arterial access given ergonomic advantages with its superficial location while prone.

Methods: Consecutive prone intra-operative cerebral angiograms completed solely via TUA over a 36-month period at a high-volume academic neurovascular center were retrospectively reviewed and analyzed. The ulnar artery access is obtained while patient is still supine before turning prone. For TUA, (1) the wrist is supinated and slightly hyper-extended, (2) ultrasound visualization is used to ensure protection of the ulnar nerve, and (3) the artery is punctured approximately 1-3cm proximal to the pisiform bone. The decision surrounding which ulnar artery to access is determined by target dominant vertebral artery.

Results: Prone TUA was attempted and successfully achieved in 8 consecutive prone craniotomies (6 microsurgical AVM resections, 2 microsurgical obliterations of dural fistula). The mean ulnar artery size was 2.4 mm and mean fluoroscopy time was 7.5min. All procedures were successfully completed without need for conversion to femoral arterial access. There were no forearm hematomas, hand ischemia, or arm nerve damage in any patients.

Conclusion : Our experience suggests that prone TUA is a feasible and safe alternative for prone intraoperative cerebral angiography. Given the lower rate of complications and excellent ergonomics, prone ulnar access should be routinely considered when performing intra-operative cerebral angiography during prone neurovascular cases in the occipital region, parietal region or posterior fossa.