Direct Revascularization Surgery Research Articles

Troubleshooting the bypass: intraoperative management of initially failed anastomosis in direct cerebral revascularization surgery.

Direct cerebral revascularization is considered as one of the most technically challenging operations in neurosurgery. Technical errors are often not identified during the case, but only after the recirculation stage, making management crucial at that time of the procedure. In this study, the authors sought to describe troubleshooting of the technical errors encountered in initially failed bypass cases. A retrospective analysis describing a single-surgeon, single-institution experience between 2014 and 2021 was performed, based on operative reports and videos, including a 30-day follow-up period. Initially failed bypass was defined if the bypass was not patent or had a significant leak after recirculation, irrespective of the final result. One hundred thirty-eight bypass cases were reviewed for complex aneurysms (n = 49), moyamoya disease (n = 59), and atherosclerosis (n = 30). Fifty-one initially failed anastomoses were identified; 43 of these were the result of a technical error. Etiologies of these failed anastomoses included a clot (n = 14), vessel kinking (n = 4), spasm (n = 5), suture-related cause (n = 5), inappropriate donor or recipient (n = 3), or lack of demand (n = 8). A major leak was attributed to an uncoagulated side branch (n = 4), vessel injury due to suture/clip placement (n = 1), or inadequate suture line coverage (n = 7). Thirty-seven (86%) of 43 cases were troubleshot successfully, as salvage maneuvers included papaverine vessel massage, donor repositioning, re-anastomosis for occlusion in select cases, local hemostatic agents, and suturing or coagulating side branches in a leak. Thirty-day follow-up revealed similar rates of patency between successfully troubleshot patients (35/37) and the rest of the cases (80/87, p = 0.6). Three major patterns of a noncompatible bypass were found: a major leak, an acute occlusion, or a delayed occlusion. Based on the authors' experience, salvage strategies proved successful, showing an eventual high patency rate. The authors suggest a gradual, structured algorithm to address this stage in surgery that may contribute specifically to cerebrovascular neurosurgeons at the beginning of their careers.

Occipital Artery to Middle Cerebral Artery Direct Bypass: A Salvage Revascularization Technique for Ischemic Moyamoya Disease

The main treatment for moyamoya disease (MMD) is revascularization surgery. Most bypasses use the superficial temporal artery (STA) as the donor vessel. However, even if the STA-middle cerebral artery (MCA) bypass is functioning, the affected hemisphere can continue to be symptomatically malperfused. We sought to assess the efficacy of salvage direct revascularization surgery using the occipital artery (OA) as a donor vessel in patients with ischemic MMD who experience continued cerebral malperfusion despite previous successful STA-MCA bypass. We retrospectively analyzed the cerebrovascular databases of 2 surgeons and described patients in whom the OA was used as the donor vessel for direct revascularization. Seven patients were included (5 women). Previous STA-MCA bypasses were direct (n= 2), indirect (n= 3), or combined/multiple (n= 2). The mean (SD) interval between STA-MCA and OA-MCA procedures was 29.2 (13.1) months. Despite an intact STA-MCA bypass in all 7 cases, all 7 patients had recurrent symptoms and demonstrated residual impaired cerebral perfusion. All 7 patients underwent successful OA-MCA direct revascularization. Follow-up perfusion imaging was obtained for 6 of 7 patients. All 6 of these patients demonstrated improved cerebral blood flow to the revascularized hemispheres. All 7 patients demonstrated clinical improvement. Patients with ischemic MMD who have continued symptoms and cerebral malperfusion despite previous successful STA-MCA bypass present a challenging clinical scenario. Our series highlights the potential utility of the OA-MCA direct bypass as a salvage therapy for these patients.

Disappearance of hemichorea as the initial presentation of moyamoya disease after revascularization surgery regardless of residual hypoperfusion evaluated by quantitative N-isopropyl-p-123I-iodoamphetamine SPECT

Background and importanceAlthough hypoperfusion of the basal ganglia or the frontal subcortical matter is suspected, the pathology of chorea in moyamoya disease remains unclarified. Herein, we report a case of moyamoya disease presenting with hemichorea and evaluate pre- and postoperative perfusion using single photon emission computed tomography with N-isopropyl-p-123I-iodoamphetamine (123I-IMP SPECT). Clinical presentationAn 18-year-old woman presented with choreic movement of her left limbs. Magnetic resonance imaging revealed an ivy sign, and 123I-IMP SPECT demonstrated decreased cerebral blood flow (CBF) and cerebral vascular reserve (CVR) values in the right hemisphere. The patient underwent direct and indirect revascularization surgery to improve cerebral hemodynamic impairment. The choreic movements entirely resolved immediately after surgery. Although CBF and CVR values in the ipsilateral hemisphere demonstrated by quantitative SPECT increased, these did not reach the normal values threshold. ConclusionChoreic movement in moyamoya disease may be related to cerebral hemodynamic impairment. Further studies are required to elucidate its pathophysiological mechanisms.

481 Troubleshooting the Bypass: Intraoperative Management of Initially Failed Anastomosis in Cerebral Extracranial – Intracranial Direct Revascularization Surgery

INTRODUCTION: Direct cerebral revascularization is considered one the most technically challenging operations in neurosurgery. Technical errors are often not identified during the completion of the anastomosis. Initial assessment and management at this moment can determine the success of the entire case, making re-circulation one of the most stressful moments in the procedure. METHODS: A retrospective analysis of direct bypass cases based on operative reports and available videos, were studied in detai. A case was defined as an “initially failed bypass”, irrespective of its final result, if after removal of the temporary clips, the bypass was not patent, or significant leak was encountered. RESULTS: 138 cases were included (109 being STA-MCA) done for flow replacement (n = 49), or for flow augmentation (n = 89). 45 initially failed anastomosis, out of which 37 were the result of a technical error encounterd. Causes were clot(n = 10), vessel kinking(n = 5), spasm(n = 6), inappropriate donor(n = 3) or recipient(n = 2), competitive flow(n = 6) or a leak(n = 5). 31/37 cases were troubleshooted successfully resulting in a working bypass. Rescue maneuvers included: Partial re-opening of the suture line and irrigation for clot, graft repositioning for kinking, papaverine-vessel massage for spasm, and partial vessel cut at the donor site for anastomosis inspection. In “local” lack of demand, a new anastomosis was done by the same donor. 30-days follow-up showed similar rates of patency between successfully troubleshooted patients and the rest of the patients (82% vs 85%, p = 0.35). CONCLUSIONS: A comprehensive approach detailing technical “corrections”, describing maneuvers and the sequence of actions done in order to “revive” the bypass, as well as their prevalence, was not previously well described. In this study we present 3 of initial failure types: a leak, acute occlusion or delayed occlusion, presenting an algorithm for intra-operative management in these cases.

Effect of combined Japanese traditional medicines, keishibukuryogan and jidabokuippo, on postoperative soft tissue swelling in adult patients undergoing revascularization surgery for ischemic moyamoya disease: A comparison of two prospective cohort studies

AbstractAimIndirect revascularization surgery for moyamoya disease (MMD) sometimes results in swelling of the soft tissues (including the temporalis muscle) compressing the cerebral hemispheres postoperatively. The present supplementary analysis of two prospective cohorts aimed to elucidate the effects of Japanese traditional medicines, keishibukuryogan and jidabokuippo, on postoperative soft tissue swelling in adult patients undergoing revascularization surgery for ischemic MMD.MethodsThirty‐two patients treated using direct revascularization surgery alone without Japanese traditional medicine (the first original study) and another 22 patients treated using indirect revascularization surgery alone with perioperative administration of keishibukuryogan and jidabokuippo (the second original study) underwent computed tomography of the head before and 3 days after surgery. The postoperative swelling rate of soft tissues in the head ipsilateral to the surgery was calculated.ResultsThe postoperative swelling rate of the soft tissues was significantly lower in patients participating in the second original study (88.8 ± 31.6%) than in those participating in the first original study (127.1 ± 31.1%) (p = 0.0002). When postoperative swelling rates of soft tissues in all 54 patients were arranged in descending order and divided into tertiles (186.7–132.0%, 130.0–92.4%, 92.3–44.3%), logistic regression analysis revealed that participation in the second original study was significantly associated with the bottom tertile of postoperative swelling rate of soft tissues (95% confidence interval, 4.90–100.12; p = 0.0098).ConclusionCombined administration of Japanese traditional medicines, keishibukuryogan and jidabokuippo, can reduce postoperative soft tissue swelling in adult patients undergoing revascularization surgery for ischemic MMD.

Changes in periventricular anastomosis after indirect revascularization surgery alone for adult patients with misery perfusion due to ischemic moyamoya disease.

Periventricular anastomosis in moyamoya disease (MMD) is an unusual angiographic finding that arises from perforating arteries such as the lenticulostriate artery (LSA), thalamic artery (THA), and anterior choroidal artery (AChA). This anastomosis is associated with increased hemorrhagic risk in MMD and can be corrected by direct revascularization surgery. The present supplementary analysis on a prospective cohort aimed to elucidate changes in periventricular anastomosis after indirect revascularization surgery alone for adult patients with misery perfusion due to ischemic MMD. Twenty-two patients with misery perfusion in the symptomatic cerebral hemisphere who underwent indirect revascularization surgery alone also underwent six-vessel cerebral angiography via arterial catheterization before and at 6months after surgery. Before surgery, two patients (9%) had positive periventricular anastomosis from the LSA and another (5%) from the AChA; all three of these periventricular anastomoses regressed after surgery, but these changes were not statistically significant (p = 0.0833). The degree of formation of collateral vessels from the LSA significantly decreased after surgery (p = 0.0143), but the degree of collateral vessels from the THA or AChA did not differ between pre- and postoperative conditions. Eight patients with postoperative regression of the collateral vessels from any perforating artery exhibited postoperative rich collateral flow from indirect revascularization. Periventricular anastomosis tended to regress after indirect revascularization surgery alone for adult patients with misery perfusion due to ischemic MMD. Collateral vessels formed from the LSA likely regressed after indirect revascularization surgery alone for such patients, but those vessels from the THA or AChA seldom changed.

Angiographic, Cerebral Hemodynamic, and Cognitive Outcomes of Indirect Revascularization Surgery Alone for Adult Patients With Misery Perfusion due to Ischemic Moyamoya Disease.

Revascularization surgery for adult patients with ischemic moyamoya disease (MMD) may improve both cognitive function and cerebral perfusion. To determine angiographic, cerebral hemodynamic, and cognitive outcomes of indirect revascularization surgery alone for adult patients with misery perfusion due to ischemic MMD (IDR group) and to test the superiority of indirect revascularization surgery for cognitive improvement by conducting comparisons with historical control patients who had undergone direct revascularization surgery (DR group) through prospective cohort study with historical controls. Twenty adult patients with cerebral misery perfusion underwent encephalo-duro-myo-arterio-pericranial-synangiosis alone. Cerebral angiography through arterial catheterization, brain perfusion single-photon emission computed tomography, and neuropsychological testing were performed preoperatively and at 6 months postoperatively. In 17 patients of the IDR group, collateral flows that were newly formed after surgery on angiograms fed more than one-third of the middle cerebral artery (MCA) cortical territory. In the IDR group, perfusion in the MCA territory was significantly increased after surgery (P < .0001), and the difference in MCA perfusion between before and after surgery was significantly greater (P = .0493) compared with the DR group. Improved cognition was significantly more frequent in the IDR group (65%) than in the DR group (31%, P = .0233). Indirect revascularization surgery alone forms sufficient collateral circulation, improves cerebral hemodynamics, and recovers cognitive function in adult patients with misery perfusion due to ischemic MMD. The latter 2 beneficial effects may be higher when compared with patients undergoing direct revascularization surgery.

Precision Medicine for Moyamoya Disease

Moyamoya disease(MMD)is a chronic, occlusive cerebrovascular disease characterized by progressive stenosis at the internal carotid artery terminus and abnormal vascular network formation at the base of the brain. Although its etiology is still unknown, recent genetic analysis identified RNF213 as an important susceptibility gene for MMD. A single nucleotide polymorphism in c.14576G>A(p.R4810K)in RNF213 was identified in 80% of patients with MMD in Japan, and RNF213 mutation was found to be significantly associated with earlier disease onset and more severe disease. More recent studies identified a significant correlation between RNF213 mutation and the intrinsic cerebral hemodynamics, such as local cerebral hyperperfusion after direct revascularization surgery for patients with MMD. These results indicate that RNF213 could be a useful biomarker for the prediction of the clinical course of MMD and/or the outcomes of revascularization surgery. Further investigation is warranted to clarify the exact mechanism by which RNF213 mutation leads to the steno-occlusive changes at the internal carotid artery terminus, development of abnormal vascular networks at the base of the brain, and ultimate cerebrovascular events in patients with MMD. This information could also be helpful in the implementation of precision medicine by providing critical information regarding the molecular target candidates in the management of MMD.

Long-Term Cognitive Changes after Revascularization Surgery in Adult Patients with Ischemic Moyamoya Disease

Introduction: Revascularization surgery for adult moyamoya disease (MMD) with ischemic presentation changes cognitive function and prevents further cerebral ischemic events. Most studies however repeated neuropsychological evaluation within 1 year after surgery. Our previous prospective cohort study of adult patients with MMD with misery perfusion who underwent direct revascularization surgery showed cognitive improvement and decline in 31% and 44%, respectively, of the patients 2 months after surgery. The present prospective study aimed to elucidate the 5-year cognitive changes after direct revascularization surgery in adult patients with cerebral misery perfusion due to ischemic MMD by following the same patients. Methods: In total, 31 patients were prospectively followed up for 5 years after direct revascularization surgery. Five types of neuropsychological tests were performed preoperatively, 2 months after surgery, and at the end of the 5-year follow-up. Cerebral blood flow (CBF) in the symptomatic cerebral hemisphere relative to that in the ipsilateral cerebellar hemisphere (hemispheric relative CBF [RCBF]) was measured using brain perfusion single-photon emission computed tomography preoperatively and at the end of the 5-year follow-up. Results: Based on results of pre- and postoperative neuropsychological tests, 11, 10, and 10 patients showed cognitive improvement, no change in cognitive function, and cognitive decline, respectively, at the end of the 5-year follow-up. These ratios were not significantly different compared with those 2 months after surgery (cognitive improvement, no change in cognitive function, and cognitive decline in 10, 8, and 13 patients, respectively). Although hemispheric RCBF was significantly greater at the end of the 5-year follow-up than before surgery in patients with cognitive improvement (80.7 ± 6.1% vs. 92.9 ± 5.5%; p = 0.0033) and in those showing no change in cognitive function (85.6 ± 3.5 vs. 91.5 ± 5.2%; p = 0.0093), this value was significantly lower at the end of the 5-year follow-up than before surgery in patients with cognitive decline (83.8 ± 3.7 vs. 81.0 ± 5.8%; p = 0.0367). Conclusion: One-third of adult patients with cerebral misery perfusion due to ischemic MMD who underwent direct revascularization surgery exhibited cognitive improvement, and one-third exhibited decline at the end of the 5-year follow-up. The former and latter patients had increased and decreased CBF, respectively, in the affected cerebral hemisphere at the end of the 5-year follow-up compared with preoperative brain perfusion.

De Novo Cerebral Microbleeds and Cognitive Decline in Cerebral Hyperperfusion After Direct Revascularization for Adult Moyamoya Disease

ObjectivesAdult patients with moyamoya disease (MMD) occasionally develop cognitive decline due to cerebral hyperperfusion following direct revascularization surgery. However, how the hyperperfusion phenomenon contributes to declines in cognitive function remains unclear. The present supplementary analysis of a prospective study aimed to determine whether cerebral hyperperfusion following direct revascularization surgery for adult MMD with ischemic presentation and misery perfusion leads to development of de novo cerebral microbleeds (CMBs) and whether postoperative cognitive decline is related to these CMBs. Materials and MethodsIn total, 32 patients who underwent direct revascularization surgery also underwent T2*-weighted magnetic resonance imaging (T2*WI) and neuropsychological testing before and 2 months after surgery. Development of cerebral hyperperfusion and hyperperfusion syndrome following surgery was defined based on brain perfusion single-photon emission computed tomography (SPECT) findings and clinical symptoms. ResultsCerebral hyperperfusion on brain perfusion SPECT (95% confidence interval [CI], 1.1–10.8; p = 0.0175) or cerebral hyperperfusion syndrome (95%CI, 1.3–15.3; p = 0.0029) was significantly associated with postoperatively increased CMBs on T2*WI. Postoperatively increased CMBs were significantly associated with postoperative cognitive decline (95%CI, 1.8–20.4, p = 0.0041). For patients with cerebral hyperperfusion on brain perfusion SPECT, the incidence of postoperative cognitive decline was significantly greater in patients with than in those without postoperatively increased CMBs (p = 0.0294). ConclusionsCerebral hyperperfusion following direct revascularization surgery for adult MMD with ischemic presentation and misery perfusion contributes to the development of de novo CMBs and postoperative cognitive decline is related to these CMBs.

Carotid ultrasonography predicts collateral development following combined direct and indirect revascularization surgery in adult ischemic Moyamoya disease

ObjectiveThe relationship between carotid ultrasonographic parameters and postoperative collateral development in adult ischemic moyamoya disease (MMD) patients who received combined direct and indirect revascularization surgery remains unclear. Herein, we investigated the postoperative changes in carotid ultrasonographic parameters in patients with adult ischemic MMD. MethodsWe studied 28 adult ischemic MMD patients (31 hemispheres) who underwent combined revascularization surgery. Patients underwent preoperative and postoperative (within 14 days and 3, 12, and 24 months after surgery) magnetic resonance imaging and carotid ultrasonography. We defined the hemisphere in which all signal intensities of the superficial temporal, middle meningeal, and deep temporal arteries were increased compared with that before surgery on magnetic resonance angiography as well-developed collateral establishment. ResultsPatients with good collateral establishment on MRA at 2-year after surgery had a lower external carotid artery (ECA) pulsatility index (PI) (P = 0.0413) and ECA/internal carotid artery (ICA) pulsatility index (PI) ratio (P = 0.0427) at 3-month post-operation. At 3-month post-operation, a cut-off ECA PI of 1.416 (sensitivity 40.0 %, specificity 92.3 %, area under the curve 0.7282, likelihood ratio 5.20, P = 0.0404) and ECA/ICA PI ratio of 0.8768 (sensitivity 50.0 %, specificity 92.31 %, area under the curve 0.7308, likelihood ratio 6.50, P = 0.0415) provided reliable values for good prediction of collateral development at 2 years after revascularization. ConclusionECA/ICA PI ratio and ECA PI at 3-month after surgery can be one of the indicators for predicting future well-developed neovascularization on MRA and better outcome in patients with adult ischemic MMD who received combined direct and indirect revascularization surgery.

Combined direct and indirect revascularization surgery for pediatric moyamoya disease using plastic surgical techniques

Combined direct and indirect revascularization surgery for pediatric moyamoya disease using plastic surgical techniques

Vessel territory mapping after cerebral revascularization surgery using selective angiographic flat detector perfusion imaging.

The technical feasibility and diagnostic potential of angiographic flat-detector perfusion imaging technique, combining digital subtraction angiography with a flat-detector computed tomography steady-state perfusion imaging, was explored in patients treated with direct or indirect revascularization surgery. This short communication is about an imaging modality with great potential for evaluation, comparison and grading of vascular perfusion territory areas and anatomical location selectively perfused by direct and indirect cerebral bypasses.

Pre-operative higher hematocrit and lower total protein levels are independent risk factors for cerebral hyperperfusion syndrome after superficial temporal artery-middle cerebral artery anastomosis with pial synangiosis in adult moyamoya disease patients-case-control study.

Superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis is a standard treatment for adult moyamoya disease (MMD) patients. Cerebral hyperperfusion (CHP) syndrome is one of the most serious complications of this procedure that can result in deleterious outcomes, but predicting CHP before revascularization surgery remains challenging. Furthermore, the hematological/serological factors associated with CHP syndrome are unknown. To investigate the correlation between pre-operative hematological/serological factors and the development of CHP syndrome after STA-MCA anastomosis with encephalo-duro-myo-synangiosis (EDMS) for MMD., a pre-operative peripheral blood test was performed within 5 days before surgery. Local cerebral blood flow (CBF) at the site of anastomosis was quantified by N-isopropyl-p-[123I] iodoamphetamine single-photon emission computed tomography 1 and 7 days after surgery, and the pre-operative CBF value at the corresponding area was measured. We defined CHP syndrome as a local CBF increase over 150% compared with the pre-operative value, which was responsible for delayed intracranial hemorrhage, transient focal neurological deterioration, and/or seizure. Then, we retrospectively investigated the correlation between peripheral blood test results and the development of CHP syndrome. CHP syndrome 1 day after STA-MCA anastomosis with EDMS was observed in nine patients (9/114 hemispheres; 7.9%). Multivariate analysis with multiple imputation revealed that higher hematocrit value and lower total protein level were significantly associated with the development of CHP syndrome (p value: 0.028 and 0.043, respectively). Higher pre-operative hematocrit levels and lower pre-operative total protein levels are novel risk factors for CHP syndrome after direct revascularization surgery in adult MMD patients.

Prediction of Cerebral Hyperperfusion after Superficial Temporal Artery-Middle Cerebral Artery Anastomosis by Three-Dimensional-Time-of-Flight Magnetic Resonance Angiography in Adult Patients with Moyamoya Disease

Introduction: Superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis is an effective surgical procedure for adult patients with moyamoya disease (MMD) and is known to have the potential to prevent cerebral ischemia and/or hemorrhagic stroke. Cerebral hyperperfusion (CHP) syndrome is one of the serious complications of this procedure that can result in deleterious outcomes, such as delayed intracerebral hemorrhage, but the prediction of CHP before revascularization surgery remains challenging. The present study evaluated the diagnostic value of preoperative three-dimensional (3D)-time-of-flight (TOF) magnetic resonance angiography (MRA) for predicting CHP after STA-MCA anastomosis for MMD. Materials and Methods: The signal intensity of the peripheral portion of the intracranial major arteries, such as the anterior cerebral artery (ACA), MCA, and posterior cerebral artery (PCA) ipsilateral to STA-MCA anastomosis, on preoperative MRA was graded (0–2 in each vessel) according to the ability to visualize each vessel on 97 affected hemispheres in 83 adult MMD patients. Local cerebral blood flow (CBF) at the site of anastomosis was quantitatively measured by N-isopropyl-p-[¹²³I]-iodoamphetamine single-photon emission computed tomography 1 and 7 days after surgery, in addition to the preoperative CBF value at the corresponding area. Then, we investigated the correlation between the preoperative MRA score and the development of CHP. Results: The CHP phenomenon 1 day after STA-MCA anastomosis (local CBF increase over 150% compared with the preoperative value) was evident in 27 patients (27/97 hemispheres; 28%). Among them, 8 (8 hemispheres) developed CHP syndrome. Multivariate analysis revealed that the hemispheric MRA score (0–6), the summed ACA, MCA, and PCA scores for the affected hemisphere, was significantly associated with the development of CHP syndrome (p = 0.011). The hemispheric MRA score was also significantly correlated with the CHP phenomenon, either symptomatic or asymptomatic (p < 0.001). Conclusion: The signal intensity of the intracranial major arteries, including the ACA, MCA, and PCA, on preoperative 3D-TOF MRA may identify adult MMD patients at higher risk for CHP after direct revascularization surgery.

Measurement of Intraoperative Graft Flow Predicts Radiological Hyperperfusion during Bypass Surgery in Patients with Moyamoya Disease

Introduction: Moyamoya disease (MMD) is a rare cerebrovascular disease associated with cerebral infarction or hemorrhage. Hyperperfusion is the most significant complication of direct bypass surgery. Previous research has shown that an increase in cerebral blood flow (CBF) is strongly related to symptomatic hyperperfusion and highlighted the importance of postoperative assessment of CBF. Objective: The principal aims of this study were to quantitatively analyze the relationship between intraoperative graft flow and increase in CBF and to evaluate the effectiveness of intraoperative graft flow measurement during bypass surgery for patients with MMD. Methods: This study included 91 surgeries in 67 consecutive adult patients with MMD who underwent direct revascularization surgery at our institution between November 2013 and September 2018. Intraoperative graft flow of the branches and main trunk was measured in all patients, after anastomosis had been established. Postoperative CBF measurements were performed under sedation, immediately after surgery. Radiological hyperperfusion was defined as focal high uptake, as determined by CBF imaging immediately after surgery. Patients were divided into two groups (radiological hyperperfusion and nonradiological hyperperfusion groups), and the relationship between intraoperative graft flow and radiological hyperperfusion was analyzed. Results: Significant differences were observed between the radiological hyperperfusion and nonradiological hyperperfusion groups in terms of intraoperative graft flow of both the branch (median 72 vs. 42 mL/min, respectively; p < 0.01) and main trunk (median 113 vs. 68 mL/min, respectively; p < 0.01). A receiver-operating characteristic analysis was performed to test the utility of intraoperative flow as a quantitative measure. We set the cutoff values for the intraoperative branch and main trunk flow at 57 mL/min (sensitivity: 0.707, specificity: 0.702; area under the curve [AUC]: 0.773; 95% confidence interval [CI]: 0.675–0.871) and 84 mL/min (sensitivity: 0.667, specificity: 0.771; AUC: 0.78; 95% CI: 0.685–0.875), respectively. Conclusions: Measuring intraoperative graft flow during bypass surgery may be an effective means of predicting hyperperfusion and could serve to facilitate early therapeutic intervention such as strict blood pressure control.

Crossed cerebellar diaschisis as an indicator of severe cerebral hyperperfusion after direct bypass for moyamoya disease.

Cerebral hyperperfusion (HP) complicates the postoperative course of patients with moyamoya disease (MMD) after direct revascularization surgery. Crossed cerebellar diaschisis (CCD) has been considered to be rarely associated with HP after revascularization surgery. This study aimed to describe the clinical features and factors associated with CCD secondary to cerebral HP after revascularization surgery for MMD. We analyzed 150 consecutive hemispheres including 101 in adults and 49 in pediatric patients who underwent combined direct and indirect bypass for MMD. Using single-photon emission computed tomography (SPECT), serial cerebral blood flow (CBF) was measured immediately after the surgery and on postoperative days 2 and 7. Pre- and postoperative voxel-based analysis of SPECT findings was performed to compare the changes in regional CBF. Multivariate logistic regression analysis was performed to test the effect of multiple variables on CCD. Asymptomatic and symptomatic HP was observed in 41.3% (62/150) and 16.7% (25/150) of the operated hemispheres, respectively. CCD was observed in 18.4% (16/87) of these hemispheres with radiological HP. Multivariate analysis revealed that the occurrence of CCD was significantly associated with symptomatic HP (p = 0.0015). Voxel-based analysis showed that the CBF increase in the operated frontal cortex, and the CBF reduction in the contralateral cerebellar hemisphere on day 7 were significantly larger in symptomatic HP than in asymptomatic HP (median 11.3% vs 7.5%; - 6.0% vs - 1.7%, respectively). CCD secondary to postoperative HP is more common than anticipated in MMD. CCD could potentially be used as an indicator of severe postoperative HP in patients with MMD.

Significance of Quantitative Cerebral Blood Flow Measurement in the Acute Stage after Revascularization Surgery for Adult Moyamoya Disease: Implication for the Pathological Threshold of Local Cerebral Hyperperfusion

Objective: Superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis is a standard surgical procedure for adult patients with moyamoya disease (MMD) and plays a role in preventing ischemic and/or hemorrhagic stroke. Cerebral hyperperfusion (CHP) syndrome is a potential complication of this procedure that can result in deleterious outcomes, such as delayed intracerebral hemorrhage, but the exact threshold of the pathological increase in postoperative cerebral blood flow (CBF) is unclear. Thus, we analyzed local CBF in the acute stage after revascularization surgery for adult MMD to predict CHP syndrome under modern perioperative management. Materials and Methods: Fifty-nine consecutive adult MMD patients, aged 17–66 years old (mean 43.1), underwent STA-MCA anastomosis with indirect pial synangiosis for 65 affected hemispheres. All patients were perioperatively managed by strict blood pressure control (systolic pressure of 110–130 mm Hg) to prevent CHP syndrome. Local CBF at the site of anastomosis was quantitatively measured using the autoradiographic method by N-isopropyl-p-[¹²³I] iodoamphetamine single-photon emission computed tomography 1 and 7 days after surgery, in addition to the preoperative CBF value at the corresponding area. We defined CHP phenomenon as a local CBF increase over 150% compared to the preoperative value. Then, we investigated the correlation between local hemodynamic change and the development of CHP syndrome. Results: After 65 surgeries, 5 patients developed CHP syndrome, including 2 patients with delayed intracerebral hemorrhage (3.0%), 1 with symptomatic subarachnoid hemorrhage (1.5%), and 2 with focal neurological deterioration without hemorrhage. The CBF increase ratio was significantly higher in patients with CHP syndrome (270.7%) than in patients without CHP syndrome (135.2%, p = 0.003). Based on receiver operating characteristic analysis, the cutoff value for the pathological postoperative CBF increase ratio was 184.5% for CHP syndrome (sensitivity = 83.3%, specificity = 94.2%, area under the curve [AUC] value = 0.825) and 241.3% for hemorrhagic CHP syndrome (sensitivity = 75.0%, specificity = 97.2%, AUC value = 0.742). Conclusion: Quantitative measurement of the local CBF value in the early postoperative period provides essential information to predict CHP syndrome after STA-MCA anastomosis in patients with adult MMD. The pathological threshold of hemorrhagic CHP syndrome was as high as 241.3% by the local CBF increase ratio, but 2 patients (3.0%) developed delayed intracerebral hemorrhage in this series that were managed following the intensive perioperative management protocol. Thus, we recommend routine CBF measurement in the acute stage after direct revascularization surgery for adult MMD and satisfactory blood pressure control to avoid the deleterious effects of CHP.

The organization of high-tech medical care of patients with ischemic heart diseasein the Far East federal region in 2004-2013

To determine both perspectives of development of high-tech medical care in Russia and actuality of possible restructuring of system of cardio-surgery care of population it is appropriate to evaluate condition of surgical and intervention treatment of ischemic heart disease i the country and regions using the example of the Far East federal region. The analyzed indices were calculated for 100 000 of adult population. In Russia, during last decade, total common morbidity of ischemic heart disease increased up to 13.25±0,11% (n ± m) and primary morbidity factually doubled. In the Far East region indices increased up to 21,34 ± 0,13% and 67,33 ± 0,15% correspondingly. In Russia, the number of patients after coronary bypass surgery in increased up to 3.3 times (percentage of patients after ischemic heart disease surgery decreased on 42.5%) and number of patients with endovascular correction increased up to 7.8 times (their percentage increased up to 37.2%). In the Far East region increasing of coronary bypass surgery increased in 12.4 times, endovascular procedures - in 32.1 times. In Russia from 2005 lethality during direct myocardium re-vascularization surgery decreased on 21.6% and in case of endovascular interventions increased up to 2.1-2.9 times, including planned operations. The dynamics of most analyzed indices corresponds to international tendencies. However, the level of coronary surgery in Russia is still significantly lower than in the developed countries of Europe and America. In the Far East region, in 2013 situation with coronary surgery looks more reassuring than in 2004-2005 when it factually stopped developing. The health care authorities are to implement in the regions more elaborated analysis ofepidemiological indices with the purpose to develop effective activities concerning indices' amelioration; to standardize evaluation of lethality in case of surgery intervention; to adjust national standards of medical care under ischemic heart disease according international standards.

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.