Superficial Temporal Artery-middle Cerebral Artery Anastomosis Research Articles

Designing a flow-controlled STA-MCA anastomosis based on the Hagen-Poiseuille law for preventing postoperative hyperperfusion in adult moyamoya disease.

Technical improvements for preventing postoperative symptomatic cerebral hyperperfusion (CHP) during superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis for moyamoya disease (MMD) were seldom reported. The aim of this study was to investigate the significance of application of a novel flow-controlled concept which voluntarily reduces the hemodynamic difference between the donor and recipient arteries based on the Hagen-Poiseuille law when performing direct anastomoses of recipient parasylvian cortical arteries (PSCAs) with anterograde hemodynamic sources from the MCA (M-PSCAs) in adult MMD. This was a retrospective observational study. Direct anastomoses of recipient M-PSCAs were performed on 89 symptomatic hemispheres in 82 adult MMD patients in our hospital from January 2020 to June 2021. They were divided into the flow-controlled group (patients who received direct anastomosis under designed flow-controlled principles) and non-flow-controlled group (patients who received conventional direct anastomosis to obtain maximum flow). The patients' basic characteristics and incidence of postoperative CHP were compared between the two groups. Risk factors for occurrence of postoperative CHP were analyzed. Overall, 36 hemispheres were included in the non-flow-controlled group and 53 in flow-controlled group. The incidences of postoperative focal (22.6%) and symptomatic CHP (5.7%) in the flow-controlled group were significantly lower than those (focal, 52.8%; symptomatic, 25.0%) in the non-flow-controlled group (p = 0.003 and 0.009, respectively). Multivariate analysis revealed that the flow-controlled concept was significantly associated with the development of focal (p = 0.005) and symptomatic (p = 0.012) CHP. The flow-controlled STA-MCA anastomosis can significantly decrease the incidence of postoperative CHP during direct anastomoses of recipient M-PSCAs in adult MMD.

Outcomes after superficial temporal artery-middle cerebral artery anastomosis combined with multiple burr hole surgery and dural inversion synangiosis for moyamoya disease in adults.

Several forms of cerebral revascularization have been carried out to treat moyamoya disease, however, the existing methods are accompanied by a variety of complications. In this study, the authors aimed to evaluate the clinical and angiographic outcomes of a new surgical procedure: superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis combined with multiple burr hole (MBH) surgery and dural inversion synangiosis for the treatment of moyamoya disease in adults. Patients treated for moyamoya disease from August 2019 to July 2021 were retrospectively reviewed. Clinical data, including perioperative complications and follow-up outcomes, were noted. Preoperative and postoperative angiograms were compared, and the diameters of the frontal branch of the superficial temporal artery (F-STA), the deep temporal artery (DTA), the distal superficial temporal artery (STA) before the bifurcation and the middle meningeal artery (MMA) were measured on preoperative and postoperative angiograms. Meanwhile, a Matsushima score was assigned from postoperative angiograms. This study included 66 patients (67 hemispheres). During the follow-up period, a median of 18 (IQR, 13-21) months, no stroke or death occurred in any of the patients. The clinical outcomes were excellent in 27 patients (40.9%), good in 34 patients (51.6%), fair in 4 patients (6.0%), and poor in 1 patient (1.5%); the overall rate of favorable clinical outcomes (excellent and good) was 92.5%. The modified Rankin Scale (mRS) score was significantly improved at follow-up (P < 0.001). There were 41 hemispheres imaged by cerebral angiography after the operation, at a median postoperative interval of 9 (IQR, 8-12) months; among them, 34 (82.9%) hemispheres had Matsushima scores of grade A and grade B. The average postoperative diameters in the STA, DTA and MMA were increased significantly in 41 hemispheres at follow-up (P < 0.001). Sixteen (24.2%) patients suffered from perioperative complications, including focal hyperperfusion syndrome (HS) in 8 (12.2%) patients, cerebral infarction in 3 (4.5%) patients (including one case accompanied by wound infection), cerebral hemorrhage in 2 (3.0%) patients, seizures in 2 (3.0%) patients, and subdural effusion in 1 (1.5%) patient. The procedure of STA-MCA anastomosis combined with MBH surgery and dural inversion synangiosis may be a safe and effective treatment for adult patients with moyamoya disease.

Outcome Following Surgical Revascularization in Patients of Moyamoya Disease with Focus on Graft Patency and Angiographic Changes.

Surgical revascularization is the mainstay of treatment in symptomatic patients of moyamoya disease (MMD). The present study analyzed the postoperative angio-architecture in pediatric and adult patients of moyamoya disease. Patients with MMD, both ischemic and hemorrhagic, were subjected to surgery. A superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis was attempted in all. It was augmented by an encephalo-duro-myo-synangiosis), this was labelled as the combined surgical group. In patients where a direct bypass was not possible encephalo-duro-arterio-myo-synangiosis (EDAMS) was performed and these patients were put in the indirect surgery group. In the postoperative period, MRA was performed in all patients to look for (a) graft patency, (b) regression of moyamoya vessels, and (c) degree of surgical neovascularization (as quantified on adapted Matsushima and Inaba grading system). Eighty-two patients underwent 131 surgical revascularization procedures. A combined surgery (STA-MCA bypass and EDAMS) was performed in 100 hemispheres and indirect surgery (EDAMS) on 31 sides. In children less than 5 years of age, STA-MCA anastomosis was possible in more than 50% of patients. Clinical improvement was seen in 85.4% of patients. Postoperative MRA demonstrated a patent bypass graft in 97% of cases. Regression of moyamoya vessels was seen in half of the cases and good surgical revascularization (type A and B) was seen in more than 80% of hemispheres in the combined surgery and indirect surgery group. Revascularization procedures led to a regression of moyamoya collaterals, appearance of surgical neo angiogenesis, and a graft patency rate of 97%. Surgical group with combined revascularization had a trend towards better collateral development.

Changes in Surgical Treatment for Pediatric Moyamoya Disease

Pediatric patients with moyamoya disease frequently exhibit extensive cerebral infarction at the time of initial presentation and even in the early postoperative period. Cerebral infarctions are more frequent in younger patients. Surgical revascularization is the treatment of choice for patients with moyamoya disease. We modified surgical strategies for patients with moyamoya disease to reduce the incidence of postoperative cerebral infarction. Between January 2004 and December 2015, 46 patients (74 hemispheres) with moyamoya disease, aged ＜18 years, were surgically treated at our hospital. Surgical strategy entailed indirect bypass by encephalo-galeo-myo-duro-synangiosis (EGMDS) (3 hemispheres) for the first era, EGMDS and superficial temporal artery-middle cerebral artery (STA-MCA) single anastomosis (67 hemispheres) for the second era, and EGMDS and double STA-MCA anastomosis (4 hemispheres) for the third era. A review of clinical findings and radiological data showed that surgical treatment is effective for patients with moyamoya disease. Direct bypass can reduce the incidence of postoperative cerebral infarction, especially in younger patients. Postoperative cerebral infarctions were observed in 8 patients, all of whom were aged ＜6 years. Of these, 5 infarctions occurred in the ipsilateral hemisphere (6.8%) and 3 in the contralateral hemisphere (4.0%). Postoperative temporary neurological deficit due to hyperperfusion that had completely resolved by the time of discharge was seen in 9 hemispheres. Considering these results, direct bypass can induce immediate improvements in cerebral circulation that are suitable for patients with rapidly progressive moyamoya disease. However, direct bypass is not completely safe for pediatric patients with moyamoya disease because of the resulting changes in postoperative cerebral hemodynamics. To prevent such complications, we recently performed STA-MCA double bypass as an initial treatment for patients with a high risk of cerebral infarction that can increase cerebral perfusion in areas supplied by both the upper and lower trunks of the middle cerebral artery in a balanced manner. The outcome of this strategy was favorable.

Preoperative platelet count may predict postoperative symptomatic cerebral hyperperfusion syndrome after superficial temporal artery–middle cerebral artery anastomosis in moyamoya patients

ObjectivePlatelets play a critical role in the inflammatory response, accompanied by microvascular endothelial dysfunction, underlying postoperative symptomatic cerebral hyperperfusion syndrome (PSCHS) after superficial temporal artery–middle cerebral artery (STA-MCA) anastomosis in moyamoya patients. We examined whether the preoperative platelet count can predict PSCHS after STA-MCA anastomosis in such patients. MethodsIn 160 adult moyamoya patients undergoing 186 STA-MCA anastomoses, preoperative (demographics, initial clinical manifestation, and Suzuki grade), intraoperative (surgical time, operative side, fluid balance, and maximum and minimum mean blood pressure before and after vessel anastomosis), immediate postoperative (APACHE 2 score), and laboratory (hemoglobin and C-reactive protein levels and white blood cell and platelet counts) data were collected retrospectively. Results84 patients (90 sides, 48.4 %) developed PSCHS with a median(IQR) onset of postoperative day 1(0–3) and duration of 4(3–7) days. The preoperative (25.2[22.8–28.0] vs. 23.1[19.7–26.2] ×104/μL, p = 0.009) platelet count was significantly higher in patients with PSCHS than in those without. The preoperative platelet count (odds ratio[95 % confidence interval], 1.14[1.03–1.27], p = 0.011), operation on the dominant hemisphere (6.84 [3.26–14.36], p < 0.001), and negative fluid balance (2.41[1.04–5.59], p = 0.040) were significant independent predictors of PSCHS. The optimal cut-off value for preoperative platelet count was 22.7 ×104/μL, and PSCHS developed more frequently in cases with a preoperative platelet count ≥ 22.7 × 104/μL (2.90[1.54–5.45]; p = 0.001). ConclusionA high preoperative platelet count may be associated with the development of PSCHS after STA-MCA anastomosis in adult moyamoya patients.

Combined STA-MCA Bypass and Encephalodurosynangiosis Versus Encephalodurosynangiosis Alone in Adult Hemorrhagic Moyamoya Disease: A 5 -Year Outcome Study

Aim: The purpose of this study was to compare the 5-year prognosis of combined superficial temporal artery- middle cerebral artery (STA-MCA) bypass and Encephalodurosynangiosis (EDAS) and EDAS alone in hemorrhagic moyamoya disease (MMD). Methods: This study included 123 adult patients admitted to Beijing Tiantan Hospital with hemorrhagic MMD between 2010 and 2015. The surgical procedures included combined revascularization of STA-MCA anastomosis with EDAS (n = 79) or EDAS alone (n = 44). We recorded basic demographic data as well as several risks factors, and used multivariate regression analysis to evaluate the predictive factor of overall survival and rebleeding-free survival. Results: Of the 123 patients with hemorrhagic MMD, the mean age was 37.97 ± 11.04 years old and the mean follow-up period was 65.9 months (ranging from 12 to 100 months). A total of 21 rebleeding events occurred in 19 patients, yielding an annual incidence of rebleeding of 3.1%. Of the 19 patients with rebleeding, 11 (57.8%) patients died of rebleeding and one patient experience 3 rebleeding events. In the combined revascularization group, 9 (11.3%) patients experienced rebleeding, of which 5 (6.3%) died. This incidence was lower than in the indirect group, where 22.7% of patients experienced rebleeding events and 13.6% died. However, no significant difference was found between these 2 groups. In Kaplan-Meier survival analysis, the combined revascularization group had a better prognosis than the EDAS alone group, and multivariate regression analysis revealed that the combined revascularization procedure was associated with a better outcome. Conclusions: Both combined revascularization and EDAS alone can reduce the risk of rebleeding in hemorrhagic MMD. Combined revascularization was found to be superior to EDAS alone in terms of preventing rebleeding events.

Superficial Temporal Artery: Middle Cerebral Artery Bypass, Our Series of 20 Cases, Surgical Technique and Indications with Illustrative Cases.

The first extracranial-intracranial (EC-IC) bypass surgery was performed by professor Yasargil in 1967 since then this procedure has been widely used in vascular neurosurgery and sometimes, in tumors excision when a vascular sacrifice is necessary. In this article, we will illustrate the surgical technique of the superficial temporal artery-middle cerebral artery (STA-MCA) bypass with two cases; a 59-year-old male and 64-year-old female who presented with an occlusion of the MCA. The male presented also with a posterior communicating artery-IC aneurysm which was clipped in the same sitting. We also studied in this paper a series of 20 patients operated in Banbuntane Hotokukai Hospital, Fujita Health University, for which a low-flow STA-MCA anastomosis was done for steno-occlusive disease or moyamoya disease. In Banbuntane Hotokukai Hospital, Fujita Health University, 20 patients were operated since 2015, 12 patients were male. Five patients presented with moyamoya disease, while 15 patients presented with vascular steno-occlusive disease. The steno-occlusion was found in internal carotid artery in nine patients. The patients were divided into two categories (steno-occlusive disease and moyamoya). STA-MCA bypass is now one of the basic techniques to master in vascular neurosurgery. It requires to perform the anastomosis correctly within the permissible time. The goal is to have a long-term patency for the anastomosed vessel.

Is Precise Targeting of the Recipient Artery in a Superficial Temporal Artery-Middle Cerebral Artery Anastomosis Crucial?

To investigate the difference in treatment outcomes according to the method used to select the recipient artery in superficial temporal artery-middle cerebral artery (STA-MCA) anastomoses. We retrospectively analyzed the cases of 35 patients who underwent an STA-MCA anastomosis for internal carotid artery/MCA occlusion or stenosis. Patients were divided into two groups based on whether the recipient artery was precisely targeted by single-photon emission computed tomography (SPECT group) or less precisely targeted by visual assessment (Visual group). Then the bypass results in both groups were evaluated postoperatively based on changes in the regional cerebral blood flow (rCBF) and clinical outcomes. The delineated recipient artery in magnetic resonance angiography (MRA) matched the intraoperatively selected artery in 87.6% of the SPECT group cases and 83.3% of the Visual group cases. The SPECT group's digital subtraction angiography (DSA) findings coincided with the intraoperative selection in 76.9% of cases, and the MRA findings corresponded with the DSA findings in 92.3%. The postoperative areas with increased rCBF matched the perfused areas of intraoperatively selected arteries in 80.0% of the SPECT group cases and 77.8% of the Visual group cases. Postoperatively increased rCBF areas matching totally or partially with preoperative low-perfusion areas were observed in all cases. The present results revealed no significant differences in the change in rCBF in the low-perfusion area between the patients whose recipient arteries were selected by SPECT or visual assessment.

Superficial temporal artery-middle cerebral artery anastomosis patency correlates with cerebrovascular reserve in adult moyamoya syndrome patients

ObjectivesTo evaluate the effectiveness of superficial temporal artery-middle cerebral artery (STA-MCA) bypass in improving cerebrovascular reserve (CVR) in Moyamoya syndrome. Patients and methodsThis prospective study included 10 consecutive patients treated for Moyamoya syndrome by STA-MCA bypass in our institution between June 2016 and January 2018. Perfusion MRI, transcranial Doppler and 99m Tc-HMPAO SPECT with acetazolamide challenge were performed before and after treatment to evaluate perfusion and cerebrovascular reserve. STA-MCA bypass was indicated for patients with history of ischemic or hemorrhagic stroke and when CVR was diminished on both transcranial Doppler and 99m Tc-HMPAO SPECT with acetazolamide challenge or brain perfusion was deteriorated on MRI. ResultsBypass anastomosis was patent in all patients at end of surgery. One patient presented partial postoperative sensorimotor deficit related to an ischemic lesion in the frontal cortical area. One patient presented regressive chronic subdural hematoma without neurological deficit. Three months after treatment, CVR was significantly improved in 8 patients and unchanged in 2, probably related to low flow. Further follow-up found CVR deterioration in 1 patient, with anastomosis occlusion at 1 year. ConclusionOur data suggest that improvement in cerebral perfusion and CVR depends on flow in the STA-MCA anastomosis in patients with Moyamoya syndrome. Systematic long-term follow-up of anastomosis flow, brain perfusion and CVR improves quantification of the benefit of STA-MCA anastomosis in terms of disease progression.

Incidence and Risk Factors of the Watershed Shift Phenomenon after Superficial Temporal Artery-Middle Cerebral Artery Anastomosis for Adult Moyamoya Disease

Objective: Superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis is the standard surgical management for adult moyamoya disease (MMD) patients, but local cerebral hyperperfusion (CHP) and cerebral ischemia are potential complications of this procedure. Recent hemodynamic analysis of the acute stage after revascularization surgery for MMD revealed a more complex and unique pathophysiological condition, the so-called “watershed shift (WS) phenomenon,” which is defined as a paradoxical decrease in the cerebral blood flow (CBF) at the adjacent cortex near the site of local CHP. The objective of this study was to clarify the exact incidence, clinical presentation, and risk factors of the WS phenomenon after direct revascularization surgery for adult MMD. Patients and Methods: Among 74 patients with MMD undergoing STA-MCA anastomosis for 78 affected hemispheres, 60 adult patients comprising 64 hemispheres underwent serial quantitative CBF analysis by N-isopropyl-p-[¹²³I] iodoamphetamine single-photon emission computed tomography after revascularization surgery. The local CBF was quantitatively measured at the site of anastomosis and the adjacent cortex before surgery, as well as on 1 and 7 days after surgery. Then, we investigated the incidence, clinical presentation, and risk factors of the WS phenomenon. Results: The WS phenomenon was evident in 7 patients (7/64 hemispheres; 10.9%) after STA-MCA anastomosis for adult MMD. None of the patients developed neurological deterioration due to the WS phenomenon, but 1 patient developed reversible ischemic change on diffusion-weighted imaging at the site of the WS phenomenon. Multivariate analysis revealed that a lower preoperative CBF value was significantly associated with the occurrence of the WS phenomenon (20.3 ± 7.70 mL/100 g/min in WS-positive group vs. 31.7 ± 8.81 mL/100 g/min in WS-negative group, p= 1.1 × 10^–2). Conclusions: The incidence of the WS phenomenon was as high as 10.9% after STA-MCA anastomosis for adult MMD. The clinical outcome of the WS phenomenon is generally favorable, but there is a potential risk for perioperative cerebral infarction. Thus, we recommend routine CBF measurement in the acute stage after revascularization surgery for adult MMD to avoid surgical complications, such as local CHP and cerebral ischemia, caused by the WS phenomenon. Concomitant detection of the WS phenomenon with local CHP is clinically important because blood pressure reduction to counteract local CHP may have to be avoided in the presence of the WS phenomenon.

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.

Biphasic Development of Focal Cerebral Hyperperfusion After Revascularization Surgery for Adult Moyamoya Disease Associated With Autosomal Dominant Polycystic Kidney Disease

BackgroundCerebral hyperperfusion (CHP) syndrome is a potential complication of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis for moyamoya disease (MMD), but its biphasic and delayed development is extremely rare. Case reportA 47-year-old woman with autosomal dominant kidney disease (ADPKD) presented with transient ischemic attacks due to MMD, and underwent left STA-MCA anastomosis. N-isopropyl-p-[123I] iodoamphetamine single-photon emission computed tomography (123IMP-SPECT) 1 day after surgery revealed asymptomatic CHP at the site of anastomosis. Strict blood pressure control and minocycline hydrochloride relieved CHP at postoperative day 7. However, 2 days later, the patient complained of sensory aphasia, and 123IMP-SPECT demonstrated significant focal CHP at the site of anastomosis accompanying high-intensity signal on magnetic resonance (MR) imaging of fluid attenuated inversion recovery (FLAIR) in her left temporal lobe near the site of anastomosis. We continued strict blood pressure control and additionally administered free radical scavenger (Edaravone) and antiepileptic agents, which gradually improved sensory aphasia. MR imaging and 123IMP-SPECT also confirmed the amelioration of the FLAIR-high lesion and focal CHP in her left temporal lobe. Two months later, the patient underwent right STA-MCA anastomosis without complications. ConclusionsAlthough the underlying mechanism is unknown, biphasic development of focal CHP after revascularization surgery in an MMD patient with ADPKD is unique. Due to the potential vulnerability of the systemic vessels in ADPKD, it is conceivable that intrinsic vascular wall fragility in MMD could be enhanced by ADPKD and have partly led to this rare complication.

Intraoperative Resuturing of Occluded Superficial Temporal Artery-Middle Cerebral Artery Anastomoses: Single-Center Retrospective Study.

In superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis, there is a certain risk of intraoperative acute occlusion of the bypass that can cause operative complications. We sought to assess the efficacy of resuturing at the same site after intraoperative acute occlusion of the bypass. In total, 129 STA-MCA anastomosis operations were performed on 125 patients at our institution. The electronic medical records of each patient were reviewed to gather information regarding intraoperative occlusion events, and the operative videos and postoperative radiologic images were also reviewed. Twelve intraoperative acute occlusions were identified. In each case, resuturing was performed after cutting all knots, flushing the thrombus, and trimming the edges of the STAs. In 11 cases, indocyanine green videoangiography and/or Doppler sonography revealed patency during the operation, which was confirmed by postoperative magnetic resonance angiography. None of the 12 cases exhibited high-signal intensities in the MCA area on diffusion-weighted images. If intraoperative acute occlusion of STA-MCA anastomosis occurs, reanastomosis at the site should be the first option.

Clinical analysis of combined revascularization in treating ischemic Moyamoya disease in adults

ObjectiveThe aim of this study was to investigate the clinical efficacy of superficial temporal artery-middle cerebral artery anastomosis (STA-MCA)+encephalo-duro-myo-synangiosis (EDMS) in treating ischemic Moyamoya disease (IMD) in adults. MethodsA total of 30 adult patients with IMD were selected to be included in the study; they underwent STA-MCA+EDMS and were followed up for 3 months to 2 years. The digital subtraction angiography findings, modified Rankin scale (mRs) score, and complications of all the patients were compared. ResultsThirty patients successfully completed the surgery. Three patients had postoperative complications (two patients with cerebral infarction on the surgical side and one patient with poor scalp healing). The postoperative morbidity rate was 10%. Angiography conducted at 3 to 6 months postoperatively showed 28 cases of anastomotic patency; the anastomotic patency rate was 93.3%. The mRs scores of the patients’ neurological function 3 months after surgery were lower than those before surgery. ConclusionSTA-MCA+EDMS is effective in treating Moyamoya disease.

Clinical and angiographic outcomes after combined direct and indirect bypass in adult patients with moyamoya disease: A retrospective study of 76 procedures.

The present retrospective study was performed to evaluate the clinical outcome, as well as post-operative collateral formation and revascularization patterns in combined bypass. Surgical revascularization has been the mainstay of treatment for moyamoya patients. A total of 76 hemispheres from 64 moyamoya patients undergoing combined superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis and encephalo-duro-myo-synangiosis (EDMS) were retrospectively reviewed. Computed tomography perfusion and DSA were routinely performed. Modified Rankin scale (mRS) scoring and Kaplan-Meier analysis were performed, and post-operative collateral grading on digital subtraction angiography (DSA), reconstruction patterns and vessel diameter were measured to evaluate the revascularization area and vascular compensatory effect. During the follow-up period, the chief complaint was partially alleviated in 57/64 patients (89.1%). In all patients, mRS was significantly decreased after the operation. Good revascularization was established in most patients at 6 months after the surgery: 92.1% of sides were scored as 2 and 77.6% were scored as 3 by post-operative collateral grading on DSA. Dominant collateral revascularization originating from EDMS was more frequent than that from STA-MCA anastomosis (31 vs. 19 hemispheres) at 6-month follow-up. Morphologically, the calibers of the STA main trunk (2.60±0.65 mm) increased profoundly at the first 10 post-operative days (3.32±1.05 mm) and shrank back to pre-operative status at 6 months (2.20±1.01 mm) and 12 months (2.36±0.73 mm) according to DSA examination. Middle meningeal artery (MMA) and deep temporal artery (DTA) demonstrated continuous augmentation during the follow-up time (from 1.30±0.46 to 1.87±0.69 mm for MMA and 1.11±0.25 to 2.11±1.16 mm for DTA). These results strongly suggested that combined STA-MCA bypass and EDMS provided efficient revascularization and reduced acute cerebral events. The direct STA-MCA bypass provided early augmentation of cerebral perfusion, whereas the indirect EDMS provided a more durable long-term revascularization, indicating a complementary association between the two revascularization methods.

Intraoperative dexmedetomidine and postoperative cerebral hyperperfusion syndrome in patients who underwent superficial temporal artery-middle cerebral artery anastomosis for moyamoya disease: A retrospective observational study.

Dexmedetomidine, a selective α2-agonist, reduces cerebral blood flow and has neuroprotective effects against cerebral ischemia/reperfusion injury in experimental animals. We examined whether intraoperative dexmedetomidine would reduce the incidence of postoperative cerebral hyperperfusion syndrome (CHS) after superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis in patients with moyamoya disease.The electronic medical records of 117 moyamoya patients who underwent STA-MCA anastomosis were reviewed retrospectively. The patients were divided into 2 groups: 48 patients received intraoperative dexmedetomidine (Group D), while 69 patients did not (Group ND). The incidence (primary outcome), onset, and duration of postoperative CHS were noted.The incidence of postoperative CHS was 45.8% and 40.6% in groups D and ND, respectively (P = 0.708). The duration of postoperative CHS was shorter in group D than in group ND (median [Q1–Q3], 5 [3–7] vs 8 [5–10] days, P = 0.021). There was no significant difference in the onset of CHS between group D and group ND (0 [0–2] vs 1 [0–3] days, P = 0.226).In conclusion, intraoperative dexmedetomidine did not reduce the incidence of postoperative CHS, although it reduced the duration of CHS, in patients who had undergone direct revascularization surgery for moyamoya disease.

CT perfusion assessment of Moyamoya syndrome before and after direct revascularization (superficial temporal artery to middle cerebral artery bypass).

To evaluate the utility of CT perfusion (CTP) for the assessment of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis in patients with Moyamoya syndrome (MMS). Twenty-four consecutive MMS patients, who underwent unilateral STA-MCA bypass surgery, received CTP before and after surgery. The relative perfusion parameter values of surgical hemispheres before treatment were compared with post-treatment values. All patients underwent CT angiography (CTA) before and after surgery in order to confirm the patency of bypass. The follow-up CTA after surgery clearly demonstrated 20 (20/24, 83.3 %) bypass arteries, whereas four (16.7 %) bypass arteries were occluded or very small. Postoperative rMTT and rTTP values (P < 0.05) of the surgical side were significantly lower than pre-operation. In patients (n = 20) with bypass patency, postoperative rCBF, rMTT and rTTP values (P < 0.05) of the surgical side were significantly improved. However, the differences of all parameters were not significant (P > 0.05) in the patients (n = 4) without bypass patency after revascularization. This study demonstrates that CTP can provide a crucial quantitative assessment of cerebral haemodynamic changes in MMS before and after STA-MCA anastomosis. Twenty-four MMS patients undergoing STA-MCA bypass received CTP pre- and post-surgery. Cerebral haemodynamics improved on the surgical side post-surgery on CTP maps. rCBF might have a better correlation with patency of the bypass artery. CTP can evaluate cerebral perfusion changes in MMS patients after cerebral revascularization.

もやもや病に対する血行再建術後 過灌流に対するミノサイクリンを用いた周術期管理の現状と問題点

Background: Cerebral hyperperfusion syndrome is a potential complication of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis for moyamoya disease (MMD). Prophylactic blood pressure lowering in combination with the use of minocycline, a neuroprotective antibiotic agent, has been suggested to reduce the risk of cerebral hyperperfusion. We therefore aimed to evaluate the results of this procedure in our larger series.Methods: N-isopropyl-p-[123I]iodoamphetamine single-photon emission computed tomography was performed 1 and 7 days after STA-MCA anastomosis on 89 hemispheres from 75 consecutive patients with MMD (10-66, mean 38 years old). Postoperative systolic blood pressure was strictly controlled under 130 mmHg with the intra-operative and postoperative intravenous administration of minocycline hydrochloride (200 mg/day). Then we investigated the incidence of perioperative neurological deterioration and radiological adverse events such as delayed intracranial hemorrhage.Results: All patients underwent technically successful revascularization surgeries, and none of them suffered permanent neurological deterioration postoperatively. Three patients suffered transient ischemic attack in the acute stage (3.4%), and one patient suffered delayed intracerebral hemorrhage (ICH), which caused transient aphasia (1.1%). Six patients (mean age of 51.3 years) demonstrated delayed intracranial hemorrhage (subarachnoid hemorrhage in 5, and ICH in one) (6.7%) while five of them remained asymptomatic.Conclusion: The administration of minocycline with strict blood pressure control may represent secure and effective postoperative management after STA-MCA anastomosis for MMD, while delayed intracranial hemorrhage, either symptomatic or asymptomatic, is a potential complication of this procedure.

もやもや病に対するSTA-MCAバイパス術中に生じる脳表静脈の赤色化と術後脳血流増加との関連

Object: Superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis for moyamoya disease improves tissue oxygen metabolism by increasing perfusion pressure. On the basis of the hypothesis that an improvement in oxygen metabolism may increase venous oxygen saturation (SO2), we assessed changes in venous redness, which reflect venous SO2, during the revascularization surgery.Methods: In this study, venous redness in subjects was quantitatively measured as an R value of RGB (red, green and blue) on the digital images of operative fields. First, to ensure whether redness of blood reflects SO2, we studied the relationship between R values and the SO2 levels of seven blood samples with various degrees of SO2. Subsequently, by reviewing the video recordings of consecutive 14 STA-MCA anastomosis for moyamoya disease, changes in the R value (ΔR) of the cortical veins were compared with those in the regional cerebral blood flow (ΔrCBF) after the surgery.Results: A positive correlation was noted between R values and SO2 of the 7 blood samples (r2 =0.847, P=0.003). The ΔR of the cortical veins during surgery positively correlated with ΔrCBF (r2 =0.473, p=0.007). Notably, prominent venous reddening was associated with an excess increase in postoperative CBF (>150%).Conclusions: During STA-MCA anastomosis, reddenings of cortical veins is proportional to increases in postoperative CBF. Prominent venous reddening, which may reflect excess oxygen supply, suggests postoperative hyperperfusion.

A case of metastatic brain tumor in the perfusion territory of superficial temporal artery-middle cerebral artery anastomosis.

Background:We report a rare case of metastatic tumor in the perfusion territory of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis.Case Description:A 63-year-old man, who had undergone left STA-MCA anastomosis in the treatment of occlusion of internal carotid artery 4 years ago, presented with a hyperintense lesion on T2-weighted image in the left frontal lobe, the perfusion territory of the prior bypass. Follow-up magnetic resonance imaging 1 month later showed enhanced tumor within the T2 hyperintense lesion. A total removal of the tumor through another craniotomy was performed. The pathologic diagnosis was metastatic carcinoma.Conclusion:This is the first report of the metastatic carcinoma by seeding of tumor cells through STA-MCA bypass flow.