Bilateral thalamic stroke after tonsillectomy in a patient with collateral extracranial anastomosis - case report

Abstract

Haemorrhage remains the most frequent and serious complication of tonsillectomy. When bleeding is recurrent, gushing, and ceases spontaneously, pseudoaneurysm of the injured artery in the proximity of the tonsillar bed should be suspected. Haemorrhage related to pseudoaneurysm occurs most commonly in the first 30 days after surgery. It can sometimes be excessive and requires a revision procedure such as external carotid artery (ECA) ligation or embolisation. During those procedures, ECA should be checked for possible anastomoses, otherwise the bleeding may persist despite the intervention. We report an unusual case of a patient with recurrent post-tonsillectomy haemorrhage due to pseudoaneurysm of the facial artery, which persisted after ECA ligation because of the presence of collateral occipital-vertebral anastomosis. Due to the recurrence of bleeding episodes, endovascular treatment was implemented. However, the embolisation was complicated by bilateral thalamic stroke with unclear mechanism. This case highlights the importance of anastomosis between ECA and the vertebrobasilar system, both in recurrence of significant post-tonsillectomy bleeding and in potential thromboembolic complications. Therefore, ECA ligation should always be accompanied by exclusion of possible anastomoses. In cases of non-life-threatening bleeding, embolisation seems to be the proper and more selective therapy.

Keywords: ligation; postoperative haemorrhage; therapeutic embolisation; tonsillectomy.

Figure 1

Computed tomography angiography of extracranial arteries. The image shows a 6-mm pseudoaneurysm of the left facial artery (arrow)

Figure 2

Digital subtraction angiography. A-B) The left vertebral artery (VA) selective angiography showed the presence of an occipital-vertebral anastomosis (arrow) between the muscular branch of the left VA and the left occipital artery with retrograde flow from the VA to the external carotid artery (ECA) in the segment above the ligation. C-D) Embolization of the trunk of the ECA was achieved by implantation of one platinum detachable coil (target 6 mm × 15 cm) and further injection of N-butyl-2-cyanoacrylate. The final angiogram (C) demonstrated subtotal occlusion of the embolized vessel with a negligible inflow by submillimeter muscular branches

Figure 3

Magnetic resonance examination, axial T2-weighted (A), diffusion-weighted images (B) as well as T1-weighted images (C, D). The images show hyperintense regions of acute ischemic stroke involving predominantly the right thalamus as well as a small part of the left thalamus (A, B). On T1-weighted images (C, D) the P1 segments of both posterior cerebral arteries revealed high signal intensity more pronounced on the right side (arrows), probably due to P1 thrombus