Safety and efficacy of dynamic catheter-directed cerebral digital subtraction angiography for diagnosis of bowhunter syndrome spectrum disorders: A systematic review of the literature

Abstract

Introduction: Dynamic catheter-directed cerebral digital subtraction angiography (dcDSA) is the gold standard for diagnosing dynamic vascular occlusion syndromes such as bowhunter syndrome (BHS). Nonetheless, concerns about its safety exist and no standardized protocols have been published to date.

Methods: We describe our methodology and insights regarding the use of dcDSA in patients with BHS. We also perform a systematic literature review to identify cases of typical and atypical presentations of BHS wherein dcDSA was utilized and report on any procedural complications related to dcDSA.

Results: Our study included 104 cases wherein dcDSA was used for the diagnosis of BHS. There were 0 reported complications of dcDSA. DcDSA successfully established diagnosis in 102 of these cases. Thirty-eight cases were deemed atypical presentations of BHS. Fourteen patients endorsed symptoms during neck flexion/extension. In eight cases, there was dynamic occlusion of bilateral vertebral arteries during a single maneuver. Three patients had multiple areas of occlusion along a single vertebral artery (VA). An anomalous entry of the VA above the C6 transverse foramen was observed in four patients. One patient had VA occlusion with neutral head position and recanalization upon contralateral lateral head tilt.

Conclusion: Our study highlights the safety and diagnostic benefits of dcDSA in characterizing the broad spectrum of BHS pathology encountered in clinical practice. This technique offers a powerful means to evaluate changes in cerebral blood flow and cervical arterial morphology in real time, overcoming the constraints of static imaging methods. Our findings pave the way for further studies on dcDSA to enhance cross-sectional imaging methods for the characterization of BHS and other dynamic vascular occlusion syndromes.

Keywords: Cerebral digital subtraction angiography; bowhunter syndrome; dynamic vascular occlusion syndrome.

Figure 1.

Preferred reporting items for systematic reviews and meta-analyses (PRISMA) diagram.

Figure 2.

An illustrative case of typical atlanto-axial bowhunter syndrome. A patient in his 70s presented with loss of consciousness with left head turn following chiropractic neck manipulation. CTA with perfusion was negative for acute infarcts but showed a dominant left VA and hypoplastic right VA. There was no evidence of vessel occlusions or dissection. (a, b) DcDSA revealed moderate to severe stenosis of the left VA with right neck rotation at the C1–2 level, consistent with atlanto-axial BHS. The patient underwent uncomplicated surgical decompression from the occiput to C7 and remains asymptomatic at 2 months post-op. CTA: computed tomography angiography; DcDSA: dynamic catheter-directed cerebral digital subtraction angiography; BHS: bowhunter syndrome; VA: vertebral artery.

Figure 3.

An illustrative case of atypical subaxial bowhunter syndrome. A patient in his early 60s with a history of recurrent, cryptogenic posterior circulation infarcts presenting with positional dizziness during neck flexion. (a) CTA revealed a large C5–6 osteophyte and entry of the left VA at the C5 transverse foramen. DcDSA was performed to evaluate for BHS. (b, c) Intraoperatively, as the patient flexed his neck with minimal left-ward rotation, there was dynamic loss of opacification of the left VA segment at C5–6 near the C5–6 posterior osteophyte and the posterior cornu of the ipsilateral thyroid cartilage (Supplemental Video 1). Transcranial Doppler recordings revealed 60 high-intensity transient signals emanating from the left VA, with no corresponding signals from the right. These findings suggested the patient's recurrent cerebellar infarcts arose from microemboli formation due to endothelial injury and blood flow stasis secondary to intermittent left VA compression from the left C5–6 osteophyte upon neck rotation. We performed coil embolization of the left VA following a successful endovascular balloon test. The patient continues to remain symptom-free 2 years post-op. BHS: bowhunter syndrome; CTA: computed tomography angiography; dcDSA: dynamic catheter-directed cerebral digital subtraction angiography; VA: vertebral artery.