Subarachnoid hemorrhage after STA-MCA bypass for the treatment of an M2 dissecting aneurysm: A case report

The treatment of middle cerebral artery aneurysms poses unique challenges, especially aneurysms at the bifurcation. Whilst historically these had been preferentially clipped, the progressively increasing sophistication of endovascular occlusive methods is tilting the balance in favour of coiling. However, for certain situations, where neither coiling nor clipping alone provides suitable aneurysm occlusion, bypass, in addition to clipping provides viable options for treatment. Of these, Superficial temporal artery to middle cerebral artery (STA-MCA) bypass remains the most common and most versatile EC-IC bypass with applications to aneurysms, Moya-Moya disease, and carotid occlusion. Subarachnoid haemorrhage (SAH) is a potential complication after a surgical bypass for aneurysms; however, the incidence, timing, prognosis, possible mechanism, and prevention are not well known. 4 Combined surgical cerebrovascular reconstruction of the STA-MCA bypass offers the opportunity to downregulate the hemodynamic stress within an aneurysm by diverting flow from the parent vessel and reducing the risk of aneurysm rupture. 5