Cortical blood flow response to hypercapnia during anaesthesia in Moyamoya disease

Hemoglobin Drop is Associated with Early Post-operative Stroke Following Revascularization Surgery for Moyamoya Disease

BACKGROUND

Postoperative stroke is a potentially devastating neurological complication following surgical revascularization for Moyamoya disease. We sought to evaluate whether peri-operative hemoglobin levels were associated with the risk of early post-operative stroke following revascularization surgery in adult Moyamoya patients.

METHODS

Adult patients having revascularization surgeries for Moyamoya disease between 1999-2022 were identified through single institutional retrospective review. Logistic regression analysis was used to test for the association between hemoglobin drop and early postoperative stroke.

RESULTS

In all, 106 revascularization surgeries were included in the study. A stroke occurred within 7 days after surgery in 9.4% of cases. There were no significant associations between the occurrence of an early postoperative stroke and patient age, gender, or race. Mean postoperative hemoglobin drop was greater in patients who suffered an early postoperative stroke compared with patients who did not (2.3±1.1 g/dL vs. 1.3±1.1 g/dL, respectively; P=0.034). Patients who experienced a hemoglobin drop post-operatively had 2.03 times greater odds (95% confidence interval, 1.06-4.23; P=0.040) of having a stroke than those whose hemoglobin levels were stable. Early postoperative stroke was also associated with an increase in length of hospital stay (P<0.001), discharge to a rehabilitation facility (P=0.014), and worse modified Rankin scale at 1 month (P=0.001).

CONCLUSION

This study found a significant association between hemoglobin drop and early postoperative stroke following revascularization surgery in adult patients with Moyamoya disease. Based on our findings, it may be prudent to avoid hemoglobin drops in Moyamoya patients undergoing surgical revascularization.

A Retrospective Study of Neurological Complications in Pediatric Patients With Moyamoya Disease Undergoing General Anesthesia

BACKGROUND

Moyamoya disease is a condition with potentially devastating and permanent neurological sequelae. Adequate volume status and blood pressure, tight control of carbon dioxide to achieve normocarbia, and providing postoperative analgesia to prevent hyperventilation are typical goals that are used during anesthetic care in these patients. The purpose of this study was to assess postanesthesia neurological complications in moyamoya patients undergoing general anesthesia for imaging studies and surgical procedures excluding neurosurgical revascularization.

METHODS

We performed a retrospective cohort study examining moyamoya patients who received general anesthesia for imaging studies and nonneurosurgical-revascularization procedures between January 1, 2001 and December 1, 2016 at our quaternary care pediatric hospital. A general anesthetic encounter was excluded if it occurred within 30 days after a revascularization surgery. The electronic medical records of study patients were analyzed for perioperative management, and neurological outcomes within 30 days of an anesthetic were assessed.

RESULTS

A total of 58 patients undergoing 351 anesthesia exposures were included in the study. Three patients experienced neurological complications, which included focal neurological weakness, seizure, and altered mental status. The incidence of complications during anesthesia encounters was 0.85% (3/351) with a 95% confidence interval of 0.28-2.62.

CONCLUSIONS

Over a 16-year period at our hospital, 3 children with moyamoya disease who underwent anesthesia for nonneurosurgical-revascularization purposes demonstrated postanesthesia neurological symptoms. The symptoms were consistent with transient ischemic attacks and all resolved without long-term sequelae.

Derivation and validation of an equation to determine the optimal ventilator setting in children undergoing intracranial revascularization surgery: A single-center retrospective study

BACKGROUND

It can be difficult to determine the appropriate ventilator settings to maintain normocapnia in children undergoing general anesthesia for surgery for moyamoya disease, especially immediately following anesthesia induction.

AIM

We conducted this study to attempt to derive an equation to predict the appropriate ventilator settings and subsequently validated the accuracy of the equation.

METHODS

A retrospective study of 91 pediatric patients less than 18 years of age who underwent cerebral revascularization for moyamoya disease at our institution. Fifty-eight patients were used to derive the equation, and the subsequent 33 patients were used to validate the equation. We calculated the required respiratory rate to attain normocapnia based on the median of all values of the minute volume during normocapnia (estimated partial pressure of arterial carbon dioxide of 38-42 mm Hg) and the assumption that the tidal volume was 8 mL/kg body weight. We derived the regression equation from the derivation data set where the required respiratory rate to attain normocapnia was represented by age. We simplified the equation by rounding coefficients to the nearest integer. The level of agreement between the respiratory rate predicted from the equation and the actual required respiratory rate was assessed in the validation group using Bland-Altman analysis.

RESULTS

The derived equation is tidal volume = 8 mL/kg body weight, respiratory rate = 24-age/min. Bland-Altman analysis in the validation group revealed that the mean bias between the predicted and actual respiratory rate was 0.29 (standard deviation, 3.67). The percentage of cases where the predicted rate was within ± 10% and ± 20% of the actual rate was 42.4% and 66.7%, respectively.

CONCLUSIONS

We derived and validated a simple and easily applicable equation to predict the ventilator settings required to attain normocapnia during general anesthesia in children with moyamoya disease.

Effects of Combined Remote Ischemic Pre-and Post-Conditioning on Neurologic Complications in Moyamoya Disease Patients Undergoing Superficial Temporal Artery-Middle Cerebral Artery Anastomosis

Superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis is the most commonly used treatment for Moyamoya disease. During the perioperative period, however, these patients are vulnerable to ischemic injury or hyperperfusion syndrome. This study investigated the ability of combined remote ischemic pre-conditioning (RIPC) and remote ischemic post-conditioning (RIPostC) to reduce the occurrence of major neurologic complications in Moyamoya patients undergoing STA-MCA anastomosis. The 108 patients were randomly assigned to a RIPC with RIPostC group (n = 54) or a control group (n = 54). Patients in the RIPC with RIPostC group were treated with four cycles of 5-min ischemia and 5-min reperfusion before craniotomy and after STA-MCA anastomosis (RIPostC). The incidence of postoperative neurologic complications and the duration of hospital stay were determined. The overall incidence of neurologic complication was significantly higher in the control group than in the RIPC with RIPostC group (13 vs. 3, p = 0.013). The duration of hospital stay was significantly longer in the control group than in the RIPC with RIPostC group (17.8 (11.3) vs. 13.8 (5.9) days, p = 0.023). Combined remote ischemic pre- and post-conditioning can be effective in reducing neurologic complications and the duration of hospitalization in Moyamoya patients undergoing STA-MCA anastomosis.

Deep hypothermic circulatory arrest for hemiarch replacement in a pediatric patient with moyamoya disease

Moyamoya disease is a chronic cerebrovascular occlusive disease, occurring predominantly in young populations, that causes cerebral ischemia and hemorrhage. Patients with moyamoya disease are at high risk of neurological complications during cardiac surgery because of perioperative hemodynamic changes. However, there is no established evidence on temperature management during cardiopulmonary bypass. Previous reports described normothermia or mild to moderate hypothermia during cardiopulmonary bypass in patients with moyamoya disease; however, surgical conditions, such as not having enough space to clamp the aorta or a clean surgical field, sometimes force us to use deep hypothermic circuratory arrest. We report a successful case of a pediatric patient with moyamoya disease who underwent deep hypothermic circulatory arrest (18 °C) for hemiarch replacement without neurological complications. Deep hypothermia may be an alternative technique for achieving cerebral protection in the context of moyamoya disease.

Moyamoya disease in pregnancy: maintenance of maternal blood pressure

Moyamoya disease is a rare cerebrovascular occlusive disorder characterized by stenosis in the circle of Willis with the development of a compensatory circulation. It has been associated with significant morbidity in pregnancy including intracranial haemorrhage, ischaemic stroke and epilepsy. We present the case of a 26-year-old woman with a previous diagnosis of moyamoya vasculopathy with bilateral superficial temporal to middle cerebral artery bypass grafting. During the second trimester, she developed significant neurological symptoms related to postural hypotension in the presence of a stenosis of the right-sided graft. The hypotension was treated with fludrocortisone therapy with improvement in blood pressure and symptoms. Moyamoya vasculopathy poses unique challenges to obstetric care. This is the first report of use of fludrocortisone for maintenance of blood pressure during pregnancy in this condition.

Hypothermic cardiopulmonary bypass for minimally invasive mitral valve plasty in adult moyamoya disease

A 43-year-old man underwent minimally invasive mitral valve plasty of a flail mitral valve. Four years previously, he had been diagnosed with moyamoya disease (MMD) by cerebral magnetic resonance imaging/angiography findings. In MMD, risk factors for cerebral stroke include changes in arterial carbon dioxide partial pressure, blood pressure, and body temperature. And during cardiopulmonary bypass (CPB), these hemodynamic changes can be challenging. However, hypothermia during CPB can decrease cerebral oxygen consumption and have a cerebral protective effect. We performed a minimally invasive mitral valve plasty, using hypothermic CPB, in a patient with MMD, without any neurological deficits.

Axillary brachial plexus blockade in moyamoya disease?

Moyamoya disease is characterized by steno-occlusive changes of the intracranial internal carotid arteries. Cerebral blood flow and metabolism are strictly impaired. The goal in perioperative anaesthetic management is to preserve the stability between oxygen supply and demand in the brain. Peripheral nerve blockade allows excellent neurological status monitoring and maintains haemodynamic stability which is very important in this patient group. Herein, we present an axillary brachial plexus blockade in a moyamoya patient operated for radius fracture.

Effects of intravenous anesthesia with propofol on regional cortical blood flow and intracranial pressure in surgery for moyamoya disease

BACKGROUND

The aim of this study was to compare the effects of inhalation anesthesia with sevoflurane and intravenous anesthesia with propofol on ICP and rCoBF during revascularization surgery for patients with MMD.

METHODS

Between 1999 and 2004, a total of 90 revascularization surgeries were performed on 58 patients. Among them, in 20 consecutive operations on 14 patients, continuous monitoring of ICP was performed with an ICP monitoring probe. Subsequently, in 14 consecutive operations on 9 patients (CoBF group), intraoperative monitoring of rCoBF was carried out with a laser Doppler flowmeter probe. The monitoring of ICP and rCoBF was performed for more than 20 minutes after the administration of anesthetic was changed from 1.5% to 2.5% sevoflurane to 6 mg/kg per hour of propofol. In all cases, the Paco(2) of these patients was strictly maintained between 38 and 40 mm Hg throughout the operations.

RESULTS

In both the ICP and the CoBF groups, the values of physiologic parameters obtained under inhalation anesthesia did not differ statistically from those obtained under intravenous anesthesia. The value for ICP under anesthesia with propofol was significantly lower than that under anesthesia with sevoflurane (P < .0001). The value for rCoBF in the frontal lobe under anesthesia with propofol was significantly higher than that under anesthesia with sevoflurane.

CONCLUSIONS

Intravenous anesthesia with propofol has potential to provide brain protection and preservation of rCBF in the frontal lobes in surgery for MMD. Whether choice of anesthetic agents might be important in surgery for MMD should be investigated further.

Intraoperative monitoring of cerebral blood oxygenation and hemodynamics during extracranial-intracranial bypass surgery by a newly developed visible light spectroscopy system

BACKGROUND

Cerebrovascular reconstruction procedures run the risk of changing the balance between oxygen supply and consumption during surgery. We assessed the value of visual light spectroscopy for detecting changes in cerebral blood oxygenation (CBO) during superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis.

METHODS

We developed a VLS monitoring system which permits continuous monitoring of CBO changes during surgery. Using the VLS, we evaluated the CBO changes in the MCA territory on the lesion side in 18 patients who underwent STA-MCA anastomosis.

RESULTS

Temporary occlusion of the MCA (M4 portion) did not change the CBO in 17 patients. However, in the patient with dissecting aneurysm, it caused decreases of oxyhemoglobin and cortical oxygen saturation (CoSo(2)) associated with an increase of deoxyhemoglobin, although these CBO changes were normalized by STA blood flow. In 5 patients, STA blood flow increased the oxyhemoglobin and CoSo(2) and decreased the deoxyhemoglobin, indicating that cortical blood flow (CoBF) was increased. The CoSo(2) before anastomosis was significantly low in the patients who showed an increase of CoSo(2) by STA blood flow (63.0% +/- 2.5%) as compared with those who did not (72.0 +/- 6.1%, P = .024).

CONCLUSION

Temporary occlusion of a cortical artery during bypass surgery did not affect the CBO in patients who had chronic cerebral ischemia, but caused acute ischemia in the patient who did not. STA blood flow increased the CoBF during surgery more frequently in patients who showed a low perfusion pressure. The VLS monitoring system is considered useful for evaluating bypass function and facilitates safe and accurate bypass surgery.

Anesthetic management for cesarean section in moyamoya disease: a report of five consecutive cases and a mini-review

We report five consecutive cases of neuraxial anesthesia for cesarean section in women with moyamoya disease. Either epidural or combined spinal-epidural anesthesia was provided, with adequate sedation using intravenous diazepam and/or opioid(s). Hemodynamic stability and normocapnia were well maintained, except in one patient who exhibited transient hypertension and hypocapnia due to anxiety. None of the parturients suffered from neurological deficit in the intra- or postoperative period, although one patient complained of numbness in her fingers at the end of surgery, but she was not hypotensive or hypocapneic. The neonates were all in good health. The literature is reviewed on the anesthetic management for cesarean section in patients with moyamoya disease.

Moyamoya disease and anesthesia

Moyamoya disease is a condition that results from bilateral stenosis or obstruction of the intracranial arteries at the base of the brain. Patients exhibit ischemic symptoms, and vascular reconstruction is the therapy of choice. Surgical treatment for Moyamoya disease is often complicated by cerebral ischemia, so the goal in perioperative management is to maintain the balance between oxygen supply and demand in the brain. This report presents three cases of Moyamoya disease in patients under 3 years of age, and discusses anesthesia management issues for pediatric patients with this condition.

[Spinal anaesthesia and Moya Moya disease]

Moya Moya is a rare disease of uncertain origin, characterised by stenosis of one or both of the internal carotid arteries and responsible of several neurological signs. We present the case of a boy with Moya Moya disease who was scheduled for an epiphisiodesis of the lateral malleola and had a spinal anaesthesia with hyperbaric bupivacaine 0.5% 10 mg without any perioperative complications. Any anaesthetic method could be used, provided special attention is given to avoid changes of capnea and blood pressure to preserve cerebral blood flow and palliate to cerebral flow steal.

Intracerebral steal phenomenon associated with global hyperemia in moyamoya disease during revascularization surgery

OBJECT

The collateral vessels in moyamoya disease appear to retain their ability to constrict during hypocapnia but not to dilate during hypercapnia. It has been claimed that hypercapnia, as well as hypocapnia, decreases the blood flow in regions perfused by collateral vessels, presumably because of intracerebral steal. If this holds true, the decrease in blood flow may be proportional to the global hyperemia in the brain. To establish appropriate hemodynamic control during revascularization surgery, the authors monitored the jugular bulb oxygen saturation (SjO2) intraoperatively, a method that could sensitively detect global hyperemia.

METHODS

A total of 17 patients, most of whom presented with transient ischemic attacks or fluctuating neurological deficits, underwent intraoperative monitoring of their SjO2 and end-tidal carbon dioxide (ETCO2) after a state of anesthesia had been induced with isoflurane (Group 1) or propofol (Group 2). In eight of these patients, the regional cerebral blood flow (rCBF) of the collateral vessel territory was also monitored by laser Doppler flowmetry during the period of cortical exposure, and a total of 113 data sets (averaged values during 2.5-minute intervals) was collected. There was fluctuation in the ETCO2 levels ranging from 36 to 44 mm Hg. The mean SjO2 level was clearly greater (p < 0.01) in Group 1 (71.8 +/- 2.2%) than in Group 2 (63.3 +/- 2.1%). An episodic fall in rCBF was observed in association with a transient increase in SjO2. Such an event was not uncommon in Group 1 and there was a greater risk of rCBF decreasing when SjO2 exceeded a cutoff level of 76% (p < 0.01). This level could sometimes be reached at a broad range of ETCO2 readings (37-44 mm Hg). In Group 2, similar events sometimes occurred when SjO2 increased beyond 70%. However, this level could be reached only with a higher ETCO2 (42-44 mm Hg). The rCBF level was negatively correlated to SjO2 (p < 0.01), but not always to ETCO2, indicating that the episodic fall in rCBF was closely related to global hyperemia rather than the absolute level of hypercapnia.

CONCLUSIONS

The observed association between a fall in rCBF and global hyperemia supports the intracerebral steal hypothesis and indicates that it is prudent to avoid excessive global hyperemia. The optimal range of CO2 for isoflurane is more restricted than that for propofol, presumably because isoflurane induces hyperemia by itself. Monitoring of SjO2 appears to represent the most practical technique for detecting global hyperemia as well as global ischemia, both of which may cause ischemic complications in moyamoya disease.

Combined spinal and epidural anesthesia for cesarean section in a parturient with moyamoya disease

We present the case of a parturient with moyamoya disease admitted to the hospital for elective cesarean section. Combined spinal and epidural technique was chosen because it allows better analgesia than epidural anesthesia and more hemodynamic stability than either general or spinal anesthesia. Ropivacaine was the local anesthetic of choice for the epidural portion because of the wide sensory-motor dissociation, thus preserving adequate respiration in the case of a high block.

Risk factors for neurologic deterioration after revascularization surgery in patients with moyamoya disease

To investigate the risk factors for postoperative neurological deterioration in patients with moyamoya disease, we retrospectively reviewed the perioperative course of 368 cases of revascularization surgery in 216 patients with this disease. Risk factors anecdotally associated with postoperative ischemic events were analyzed by comparing groups with or without a history of such events on the operative day. Ischemic events were noted in 14 cases (3.8%), 4 of which were defined as strokes and the others as transient ischemic attack (TIA). Postoperative neurological deterioration more often developed in patients who suffered from frequent TIAs, had precipitating factors for TIA, and underwent indirect nonanastomotic revascularization. The authors conclude that the incidence of postoperative ischemic events were related more to the severity of moyamoya disease and the type of surgical procedure than to other factors, including anesthetic management.

IMPLICATIONS

Although preventing stroke is the major concern for patients with moyamoya disease, risk factors for perioperative cerebral ischemia have not been clarified. We retrospectively analyzed the perioperative course in 368 cases with this disease and found that the severity of the disease and type of surgical procedure were major determinants of postoperative cerebral ischemia.

Intraoperative monitoring of jugular bulb oxygen saturation in patients with moyamoya disease

The jugular bulb oxygen saturation (SjO2) and end-tidal carbon dioxide (ETCO2) were monitored continuously during surgery in six cases of Moyamoya disease who had demonstrated multiple episodes of transient ischemic attacks (TIAs) and/or fluctuating neurological deficits preoperatively. The arterial carbon dioxide tension (PaCO2) levels were also measured repeatedly at predetermined interval. In two cases (group H), the ETCO2 was controlled at hypercapnic levels during surgery (45.5 +/- 1.5 mmHg) and the remaining four (group N) were operated on in a normocapnic state (39.0 +/- 2.0 mmHg). The group H patients demonstrated high levels of SjO2 ranging from 72 to 85%, indicative of excessive hyperemia. One of the group H patients demonstrated mild and transient motor weakness postoperatively. The group N patients demonstrated normal levels of SjO2 ranging from 66 to 78%. All the patients in both groups demonstrated fluctuations in SjO2 levels in clear positive correlation with spontaneous changes in PaCO2 levels. The present findings indicated that: (1) Global carbon dioxide reactivity of cerebral perfusion is well preserved in patients with Moyamoya disease; and (2) hypercapnia in these patients often causes excessive hyperemia. The occurrence of postoperative neurological deficits in association with such an excessive hyperemia suggests that hyperapnia during surgery is not always beneficial. Intraoperative monitoring of SjO2 is useful for maintaining cerebral perfusion within the optimum range.

Indirect revascularization for moyamoya disease: is there a beneficial effect for adult patients?

BACKGROUND

It is generally accepted that excellent development of collateral circulation can be achieved through indirect nonanastomotic bypass procedures for pediatric patients with moyamoya disease. However, there are no definitive conclusions about the effect of indirect revascularization for adult patients. To clarify the value of indirect bypass surgery for adult moyamoya disease, we have analyzed their follow-up angiographic results in comparison with those of the pediatric patients.

METHODS

Between 1989 and 1993, 23 patients underwent combined direct and indirect bypass surgery. They consisted of 16 adults (mean age, 35; range, 20-59) and seven children (mean age, 10; range, 3-16). The main symptoms were those due to cerebral ischemia in all but 1 of 23 patients. Preoperative cerebral blood flow studies showed all patients to have decreased vascular reserve (misery perfusion). Postoperative follow-up angiography was done in all patients at a median of 6 months after the surgery.

RESULTS

All pediatric patients showed good or moderate development of collaterals through the indirect bypass. Among the adult group, seven patients aged 20 to 29 had angiographic results similar to those of the pediatric group . On the other hand, nine patients older than 30 had results contrary to those of pediatric patients: (1) the degree of indirect revascularization declined to moderate or poor grades (especially in patients older than 40) and (2) the degree of direct bypass filling improved to high or medium grades.

CONCLUSIONS

The results suggest that advancing age apparently affects the development of collateral formation through the indirect bypass. Consequently, direct bypass is thought to be the main treatment option for patients older than 40.