PERIOPERATIVE CONCERNS IN THE SURGICAL MANAGEMENT OF PATIENTS WITH MOYAMOYA SYNDROME

PERIOPERATIVE ANESTHESIA CONCERNS IN THE SURGICAL MANAGEMENT OF PATIENTS WITH MOYAMOYA DISEASE

⌛️Moyamoya disease is characterized by progressive occlusion of the distal portion of the Internal Carotid Artery and the proximal Anterior and Middle Cerebral Arteries. 

⌛There is production of lots of factors promoting angiogenesis. This will cause 

(1) intimal proliferation of smooth muscle and eventual occlusion of vessels.

(2)Profuse lenticulostriate collateral formation at the base of the brain (These collaterals are known as Moyamoya vessels) 

(3)Vasodilatation of collaterals

⌛️Patients are at risk for both hemorrhagic ( due to rupture of the abnormal vessels) and ischemic stroke ( due to ischemia because of vasoocclusion) .

⌛️Presentation:

🔹Ischemic (80%): stroke , TIA etc

🔹Others: epilepsy (5%), ICH (2.5%)

⌛️On cerebral angiography, in more advanced stages of the disease, the hemispheric perfusion appears as a ‘puff of smoke’, from which the disease derives its name (Moyamoya= Puff of smoke in Japanese).

⌛️Associations: Optic/ hypothalamic glioma , Craniopharyngoma , NF-1 , Renal Artery Stenosis , Hypertension

⌛️Usual neurosurgical treatment involves Superficial Temporal Artery to Middle Cerebral Artery (MCA) Anastamosis through a small craniotomy, if there is a suitable MCA target. If not, an encephalo-duro-arterio-synangiosis (EDAS) can be performed by opposing a Superficial Temporal Artery pedicle to the cortical surface. This helps collateral formation from extra to intra cranial circulation over time (months to years).

⌛Intraoperative Concerns: ️Excessive hypertension may cause hemorrhage from friable vessels and hypotension may cause ischemic stroke from hypoperfusion

⌛️Blood pressure, blood volume, and PaCO2 require careful monitoring because moyamoya patients have a diminished cerebral perfusion reserve and deviation from normal levels can result in stroke.

⌛️So we have to take special care to avoid hypotension , hypovolemia ( give optimal preoperative, intraoperative and postoperative hydration) hyperthermia, and hypocarbia ( to avoid hypocarbia induced cerebral vasoconstriction)

#neurology , #anesthesia , #moyamoya , #stroke , #neurosurgery , 

Reference 

Surgical Management of Moyamoya Syndrome Edward R. Smith, R. Michael Scott , Skull Base. 2005;15(1):15-26.

Parray T, Martin TW, Siddiqui S. Moyamoya disease: a review of the disease and anesthetic management. J Neurosurg Anesthesiol. 2011 Apr;23(2):100-9.