**4.1 Anesthetic consideration in the obstetric patient with MMD**

Parturients with moyamoya syndrome should be treated with tight blood pressure control. Hypotension and hypertension should be avoided. Peripartum pain control is crucial to preventing pain-related hyperventilation and resultant cerebral vasoconstriction. Because cerebral aneurysms may develop with disease progression, these patients are at higher risk of intracranial hemorrhage than the general population. The development of cerebral aneurysms may be secondary to chronic hypertension or regional vessel constriction in moyamoya. Additionally, multiple tiny collateral arterioles develop at sites of proximal arterial occlusion which are prone to rupture. Hypercoagulability, venous stasis, and endothelial lesion are common in pregnancy and may contribute to stroke. Therefore, the anesthetic goals for a parturient with known Moyamoya syndrome are to avoid hypertension, which can *Perioperative Considerations for Revascularization and Non-Revascularization Surgeries… DOI: http://dx.doi.org/10.5772/intechopen.96564*

precipitate the hemorrhage, and avoid hypotension or hypocapnia that can reduce placental perfusion and the already compromised cerebral blood flow. The decision for timing and method of delivery in MMD patients is based on reducing risks associated with hemodynamic instability. Control of hemodynamic fluctuations, minimizing anxiety and pain, and Valsalva, and meticulous fluid management during intrapartum are the main components for maintaining optimal end-organ perfusion of the mother and fetus. More than 70% of parturients with MMD undergo an elective cesarean section. This is the delivery route of choice to prevent intracranial hemorrhage due to hypertension during labor. General anesthesia and neuraxial anesthesia have been reported as successful for the cesarean section [67–71]. However, both techniques are associated with sudden hypotension which may progress to ischemic events. General anesthesia is chosen for better control of hypotension (common in spinal anesthesia, leading to cerebral hypoperfusion). Tracheal intubation during general anesthesia may cause hypertension resulting in intracranial hemorrhage and general anesthesia also carries the risk of aspiration. Care should be taken during direct laryngoscopy to reduce sympathetic drive. Also, the technique could prevent hyperventilation secondary to maternal anxiety, which causes hypocapnia and decreases cerebral blood flow. Normotension and normocapnia should be the goals during general anesthesia. Vaginal delivery is considered in MMD patients at low risk for intracranial hemorrhage, such as those who underwent bypass surgery or without a history of bleeding [72]. Most affected parturient undergo successful cesarean deliveries under neuraxial anesthesia (spinal, epidural, or combined spinal-epidural anesthesia), often with invasive arterial hemodynamic monitoring; as it provides easier monitoring for neurological changes as well as preventing hypertension associated with intubation during general anesthesia. Additionally, a multidisciplinary approach (i.e., anesthesiologist, obstetrician, fetal medicine, and neurosurgery) is necessary to constantly manage underlying diseases.
