Revascularization Surgery In Patients Research Articles

A High Immediate Postoperative Systemic Immune-inflammation Index Is Associated With Postoperative Symptomatic Cerebral Infarction in Moyamoya Patients Undergoing Combined Revascularization Surgery.

Inflammation plays a role in the pathogenesis of cerebral infarction. Postoperative symptomatic cerebral infarction (SCI) is a complication after revascularization surgery in patients with moyamoya disease (MMD). We investigated the association between the systemic-immune-inflammation index (SII) and postoperative SCI during hospital stay in such patients. Perioperative data were retrospectively obtained from 681 MMD patients who underwent revascularization surgery. SII cutoff values were identified as those where the sum of sensitivity and specificity associated with SCI were highest. Patients were divided into 4 subgroups according to the preoperative and immediate postoperative cutoff SII: HH (preoperative and postoperative SII high, n=22), LH (low preoperative and high postoperative SII, n=68), HL (high preoperative and low postoperative SII, n=125), and LL (preoperative and postoperative SII low, n=466). Postoperative SCI occurred in 54 (7.6%) patients. The cutoff values for preoperative and immediate postoperative SII were 641.3 and 1925.4, respectively. Postoperative SCI during hospital stay was more frequent in the high postoperative SII group than in the low postoperative SII group (25.6% vs. 4.9%; P<0.001). Multivariate analysis revealed that a high immediate postoperative SII was a predictor of postoperative SCI (odds ratio, 11.61; 95% CI: 5.20-26.00; P<0.001). Postoperative SCI was lower in group LL than in group LH (3.6% vs. 23.5%, P<0.008) and was lower in group HL than in groups HH and LH (9.6% vs. 31.8% and 23.5%, both P<0.05). A high immediate postoperative SII was associated with postoperative SCI during hospital stay in MMD patients who underwent revascularization surgery.

Combined Direct and Indirect Revascularisation With Superficial Sparing of Temporalis Muscle in Moyamoya Disease: Operative Technique: 2-Dimensional Operative Video.

The primary objective of revascularization surgery for moyamoya disease (MMD) is to augment cerebral blood flow and prevent disease progression.1 There are several options for bypass surgery, including direct methods such as superficial temporal artery-middle cerebral artery anastomosis, indirect bypasses such as encephalomyosynangiosis, encephaloduroarteriosynangiosis or encephaloduroarteriomyosynangiosis, or combined procedures.2-5 In our institution, we undertake a combined approach involving multiple low-flow bypasses and a modified indirect bypass technique, with additional attention to achieving an optimal cosmetic result. Given that MMD often affects young patients, considering cosmesis as a significant factor in managing this condition should be standard practice. We present our modified operative technique of a combined approach to revascularization surgery in patients with MMD with particular emphasis on the indirect bypass procedure. The temporalis muscle is divided in two parts in the sagittal plane where the deeper portion is mobilized to perform an EMS, and the superficial portion is reattached to the bone flap to maintain cosmetic symmetry. A 23-year-old woman presented with a 6-month history of transient left-sided hemiparesis on a background of MMD (previous left-sided revascularization surgery). Subsequent imaging demonstrated worsening right internal carotid artery stenosis. The patient and her family were extensively counseled and decision to proceed with right-sided bypass surgery was undertaken (Video). The patient had an unremarkable postoperative course and was discharged home on day 14. Institutional review board approval was not required in our institution. The patient consented to the procedure and to the publication of his/her images.

Development and validation of machine learning models to predict postoperative infarction in moyamoya disease.

Cerebral infarction is a common complication in patients undergoing revascularization surgery for moyamoya disease (MMD). Although previous statistical evaluations have identified several risk factors for postoperative brain ischemia, the ability to predict its occurrence based on these limited predictors remains inadequately explored. This study aimed to assess the feasibility of machine learning algorithms for predicting cerebral infarction after revascularization surgery in patients with MMD. This retrospective study was conducted across two centers and harnessed data from 512 patients with MMD who had undergone revascularization surgery. The patient cohort was partitioned into internal and external datasets. Using perioperative clinical data from the internal cohort, three distinct machine learning algorithms-namely the support vector machine, random forest, and light gradient-boosting machine models-were trained and cross-validated to predict the occurrence of postoperative cerebral infarction. Predictive performance validity was subsequently assessed using an external dataset. Shapley additive explanations (SHAP) analysis was conducted to augment the prediction model's transparency and to quantify the impact of each input variable on shaping both the aggregate and individual patient predictions. In the cohort of 512 patients, 33 (6.4%) experienced postrevascularization cerebral infarction. The cross-validation outcomes revealed that, among the three models, the support vector machine model achieved the largest area under the receiver operating characteristic curve (ROC-AUC) at mean ± SD 0.785 ± 0.052. Notably, during external validation, the light gradient-boosting machine model exhibited the highest accuracy at 0.903 and the largest ROC-AUC at 0.710. The top-performing prediction model utilized five input variables: postoperative serum gamma-glutamyl transpeptidase value, positive posterior cerebral artery (PCA) involvement on preoperative MRA, infarction as the rationale for surgery, presence of an infarction scar on preoperative MRI, and preoperative modified Rankin Scale score. Furthermore, the SHAP analysis identified presence of PCA involvement, infarction as the rationale for surgery, and presence of an infarction scar on preoperative MRI as positive influences on postoperative cerebral infarction. This study indicates the usefulness of employing machine learning techniques with routine perioperative data to predict the occurrence of cerebral infarction after revascularization procedures in patients with MMD.

Safety of antiplatelet therapy during the perioperative period of revascularization surgery for moyamoya disease patients with ischemic onset.

For patients with moyamoya disease, antiplatelet agents are often used during the perioperative periods of revascularization surgeries to prevent ischemic events. However, antiplatelet therapy is associated with the risk of hemorrhagic complications. Further, the influence of antiplatelet therapy on perioperative ischemic or hemorrhagic complications has not been investigated. This study aimed to determine the impact of antiplatelet agents on adult moyamoya disease patients with ischemic onset during the perioperative period. From January 2016 to December 2020, 183 consecutive combined (direct and indirect) revascularization surgeries for moyamoya disease patients were performed. Among these surgeries, 96 consecutive combined revascularization surgeries for adult moyamoya disease patients with ischemic onset were analyzed and perioperative ischemic and hemorrhagic complications were reviewed. Antiplatelet agents were continued during the perioperative period including on the day of surgery and the day after the surgery. Among 96 surgeries, no hemorrhagic complications occurred postoperatively. Infarction occurred in five cases (5.2%). Among the five cases, neurological deficits persisted in two cases and improved in three. The median value of bleeding volume was 112.5 mL (interquartile range, 80.0 - 200.0). Twenty-five cases (26.0%) needed blood transfusion. The modified Rankin Scale score deteriorated in two cases due to cerebral infarction. The incidence of hemorrhagic and ischemic complications after combined revascularization surgery in patients with ischemic moyamoya disease under antiplatelet therapy was low, indicating the safety of continued antiplatelet therapy.

Increased Parenchymal Free Water May Be Decreased by Revascularization Surgery in Patients with Moyamoya Disease.

Moyamoya disease (MMD) is a cerebrovascular disease associated with steno-occlusive changes in the arteries of the circle of Willis and with hemodynamic impairment. Previous studies have reported that parenchymal extracellular free water levels may be increased and the number of neurites may be decreased in patients with MMD. The aim of the present study was to investigate the postoperative changes in parenchymal free water and neurites and their relationship with cognitive improvement. Multi-shell diffusion MRI (neurite orientation dispersion and density imaging and free water imaging using a bi-tensor model) was performed in 15 hemispheres of 13 adult patients with MMD (11 female, mean age 37.9 years) who had undergone revascularization surgery as well as age- and sex-matched normal controls. Parameter maps of free water and free-water-eliminated neurites were created, and the regional parameter values were compared among controls, patients before surgery, and patients after surgery. The anterior and middle cerebral artery territories of patients showed higher preoperative free water levels (P ≤ 0.007) and lower postoperative free water levels (P ≤ 0.001) than those of normal controls. The change in the dispersion of the white matter in the anterior cerebral artery territory correlated with cognitive improvement (r = -0.75; P = 0.004). Our study suggests that increased parenchymal free water levels decreased after surgery and that postoperative changes in neurite parameters are related to postoperative cognitive improvement in adult patients with MMD. Diffusion analytical methods separately calculating free water and neurites may be useful for unraveling the pathophysiology of chronic ischemia and the postoperative changes that occur after revascularization surgery in this disease population.

Vascular resistance index and the immediate hemodynamic success of lower limb distal artery revascularization.

Revascularization surgery is used to attempt to restore blood flow to the foot in patients with critical ischemia (CI) caused by peripheral arterial occlusive disease of the lower limbs (LL). Ultrasonography with Doppler (USD) SAH emerged in recent years as a highly valuable method for planning this surgical intervention. To evaluate the relationship between the resistance index (RI), measured with USD, and immediate hemodynamic success of LL revascularization surgery in patients with CI. The study design was a prospective cohort assessing 46 patients with LL CLI who underwent operations to perform infrainguinal revascularization by angioplasty or bypass from August 2019 to February 2022. All patients underwent preoperative clinical vascular assessment with USD including measurement of the RI of distal LL arteries, LL arteriography, and measurement of the ankle-brachial index (ABI). All patients had their ABI measured again in the immediate postoperative period. Forty-six patients were assessed, 25 (54.3%) of whom were male. Age varied from 32 to 89 years (mean: 67.83). Hemodynamic success was assessed by comparison of preoperative and postoperative ABI, showing that hemodynamic success was achieved in 31 (67.4%) patients after revascularization surgery (ABI increased by 0.15 or more). A positive correlation (p ≤ 0.05) was observed between the RI of the distal revascularized LL artery and immediate hemodynamic success assessed by ABI (lower RI and hemodynamic success). This study observed a positive correlation between the resistance index of the distal artery and immediate hemodynamic success of lower limb revascularizations, as assessed by the ankle-brachial index, so that the lower the RI the greater the hemodynamic success achieved.

Analysis of vascular perfusion territory using selective intraarterial injection CT angiography before and after revascularization surgery in patients with moyamoya disease.

In moyamoya disease (MMD), blood flow to the internal carotid artery (ICA) system is supplied via the basal fine vascular network, leptomeningeal anastomoses, and transdural collateral vessels from the external carotid artery (ECA). After revascularization, there is a dramatic change in cerebral perfusion to the ECA system. Understanding this shift in blood supply is important for evaluating treatment efficacy and elucidating the postoperative pathophysiology. However, anatomical and quantitative methods for doing so have not yet been established. In the present study, selective intraarterial injection CT angiography (iaCTA) was performed in patients with MMD, and blood supply changes in each arterial system before and after revascularization surgery were evaluated. This study included 10 hemispheres in 10 patients who underwent combined revascularization surgery for adult MMD. Digital subtraction angiography was performed before and 3 months after surgery, and selective iaCTA was performed from the ICA, ECA, and vertebral artery (VA) at the same times in a hybrid CT/digital subtraction angiography suite. The anatomical distribution of each vessel was determined and perfusion volume was measured quantitatively on contrast-enhanced axial CT images. Selective iaCTA clearly depicted the anatomical distribution of perfusion for each vessel. Conversion of blood supply from the ICA and VA to the ECA system was observed in the cerebral cortices and insulae but not in the basal ganglia. The mean volume of perfusion territories of the ECA (preoperative 0.9 cm3, postoperative 98.8 cm3); ICA (preoperative 225.7 cm3, postoperative 159.3 cm3); and VA (preoperative 244.0 cm3, postoperative 163.6 cm3) in the cerebral hemispheres changed significantly after revascularization. There was a correlation between increase in the ECA territory volume and decrease in the VA territory volume due to revascularization (R = -0.84, p < 0.005). Selective iaCTA enabled clear visualization of anatomical changes in each vascular perfusion territory and quantitative measurement of each perfusion volume. Perfusion conversion to the ECA system after bypass surgery was observed in the cortical regions and in the insulae on the bypass operation sides, but not in the basal ganglia. Combined revascularization promoted the development of ECA-perfused territory, which correlated with a decrease in hemodynamic burden of the posterior cerebral artery.

Prevention of postoperative stroke in pediatric moyamoya patients: a standardized perioperative care protocol.

Perioperative stroke is a major complication of revascularization surgery in patients with moyamoya. Vomiting is common after neurosurgical procedures and may result in acute changes in intracranial pressure and cerebral blood flow. The authors instituted a standardized perioperative nausea and vomiting protocol for children with moyamoya undergoing indirect bypass surgery at their institution and analyzed its association with perioperative stroke. They hypothesized that instituting a standardized perioperative nausea and vomiting protocol would be associated with reduction in the number of perioperative strokes in children with moyamoya undergoing indirect bypass surgery. The authors retrospectively reviewed consecutive cases of children and young adults with moyamoya who underwent indirect bypass surgery before and after implementation of a new perioperative nausea and vomiting protocol at a single institution. They compared the rate of strokes in the perioperative period (postoperative days 0 and 1) in the 31 months following implementation to 31 months prior to implementation using Fisher's exact test. The median ages pre- and postimplementation were 8.5 (IQR 4-12) years and 8.3 (IQR 5-15) years, respectively. There were no significant differences between the cohorts in disease severity or other potentially confounding factors. In the 31 months prior to initiation of the perioperative nausea and vomiting protocol, there were 5 strokes in 137 surgically treated hemispheres (3.6%). After initiation of the protocol, there were no strokes in 114 surgically treated hemispheres (p = 0.065). Instituting a standardized perioperative nausea and vomiting protocol was associated with reduction in perioperative strokes in children with moyamoya treated with indirect bypass surgery.

Reconstruction of Scalp Defects Using Rotational Flaps After Revascularization Surgery in Patients with Moyamoya Disease

Treating scalp defects after revascularization surgery is difficult because the scalp microcirculation is severely compromised. We aimed to review the clinical effects of using rotational flaps in scalp defect reconstruction and explore risk factors for wound-related complications (WRC) after reconstruction surgery. We retrospectively identified patients with scalp defects after combined revascularization surgery who were surgically treated with rotational flap reconstruction at our institution between January 2018 and December 2022. We analyzed treatment results in different surgical technique and revascularization strategy cohorts, including direct bypass superficial temporal artery branch selection, indirect bypass types, and skin incisions. Eleven patients were included. The superficial temporal artery parietal branch was selected for direct bypass surgery in 10 (90.9%) patients, 4 (40%) of whom had WRC after flap reconstruction. Five types of indirect bypass surgeries were performed; three patients treated by encephalo-duro-myo-arterio-perio-synangiosis and 1 patient treated by encephalo-duro-myo-perio-synangiosis had WRC after flap reconstruction. Question mark (n= 6, 54.5%), curved (n= 4, 36.65%), and Y-shaped (n= 1, 9.1%) incisions were used; in the first three incision cohorts, 2 patients in each cohort had WRC after flap reconstruction. Patients had the following commonalities that may be risk factors for WRC after flap reconstruction: 1) wounds with nonviable bone exposure after revascularization surgery; 2) three or more tissues used as donor tissues and donor tissues containing the periosteum; and 3) thin scalp around the defect.

Safety and efficacy of remote ischemic conditioning in adult moyamoya disease patients undergoing revascularization surgery: a pilot study.

Revascularization surgery for patients with moyamoya disease (MMD) is very complicated and has a high rate of postoperative complications. This pilot study aimed to prove the safety and efficacy of remote ischemic conditioning (RIC) in adult MMD patients undergoing revascularization surgery. A total of 44 patients with MMD were enrolled in this single-center, open-label, prospective, parallel randomized study, including 22 patients assigned to the sham group and 22 patients assigned to the RIC group. The primary outcome was the incidence of major neurologic complications during the perioperative period. Secondary outcomes were the modified Rankin Scale (mRS) score at discharge, at 90 days post-operation, and at 1 year after the operation. The outcome of safety was the incidence of adverse events associated with RIC. Blood samples were obtained to monitor the serum concentrations of cytokines (VEGF, IL-6). No subjects experienced adverse events during RIC intervention, and all patients could tolerate the RIC intervention in the perioperative period. The incidence of major neurologic complications was significantly lower in the RIC group compared with the control group (18.2% vs. 54.5%, P = 0.027). The mRS score at discharge in the RIC group was also lower than the control group (0.86 ± 0.99 vs. 1.18 ± 1.22, P = 0.035). In addition, the serum IL-6 level increased significantly at 7 days after bypass surgery in the control group and the serum level of VEGF at 7 days post-operation in the RIC group. In conclusion, our study demonstrated the neuroprotective effect of RIC by reducing perioperative complications and improving cerebral blood flow in adult MMD patients undergoing revascularization surgery. Thus, RIC seems to be a potential treatment method for MMD. ClinicalTrials.gov, identifier: NCT05860946.

Nomogram to Predict Good Neoangiogenesis After Indirect Revascularization Surgery in Patients with Moyamoya Disease: a Case-control Study.

Indirect bypass surgery is an effective treatment for moyamoya disease (MMD), but the success of the surgery depends on the formation of spontaneous collateral vessels, which cannot be accurately predicted before surgery. Developing a prediction nomogram model for neoangiogenesis in patients after indirect revascularization surgery can aid surgeons in identifying suitable candidates for indirect revascularization surgery. This retrospective observational study enrolled patients with MMD who underwent indirect bypass surgery from a multicenter cohort between December 2010 and December 2018. Data including potential clinical and radiological predictors were obtained from hospital records. A nomogram was generated based on a multivariate logistic regression analysis identifying potential predictors of good neoangiogenesis. A total of 263 hemispheres of 241 patients (mean ± SD age 24.38 ± 15.78years, range 1-61years) were reviewed, including 168 (63.9%) hemispheres with good postoperative collateral formation and 95 (36.1%) with poor postoperative collateral formation. Based on multivariate analysis, a nomogram was formulated incorporating four predictors, including age at operation, abundance of ICA moyamoya vessels, onset type, and Suzuki stage. The C-index for this nomogram was 0.80. Calibration curve and decision-making analysis validated the fitness and clinical application value of this nomogram. The nomogram developed in this study exhibits high accuracy in predicting good neoangiogenesis after indirect revascularization surgery in MMD patients. This model can be very helpful for clinicians when making decisions about surgical strategies for MMD patients in clinical practice.

Delta-Like Factor 1 Negatively Regulates Angiogenesis as a Target Gene of MIR-126-5P after Indirect Revascularization Surgery in Patients with Moyamoya Disease

Introduction: Moyamoya disease (MMD) is a chronic cerebral hypoperfusion state with increased narrowing of the intracranial internal carotid artery. Objectives: The main objective of the study is to analyses the delta-like factor 1 negatively regulates angiogenesis as a target gene of miR-126-5p after indirect revascularization surgery in patients with moyamoya disease. Material and methods: This retrospective study was conducted in Akhtar Saeed Medical College Lahore during 2020 to 2021. First, we compared the DLK1 expression in DM tissues from patient with moyamoya disease (n = 8) and unruptured aneurysms (n = 8, control group). DM samples (1.0 × 0.5 cm) were collected from patients with moyamoya disease during revascularization procedures. DM samples were harvested from the temporal part of the head and stored for further use. Results: EPC markers CD31, VE-cadherin, and VEGFR-2 were strongly expressed in cultured cells, while hematopoietic marker CD133 did not display remarkable expression, suggesting highly purified EPC isolation. Practical implication: This study will be helpful in EC proliferation and angiogenesis. Conclusion: It is concluded that DLK1, a target gene of miR-126-5p, negatively regulates EC proliferation and angiogenesis and that downregulating DLK1 expression potentially promotes angiogenesis in chronically ischaemic brains. Keywords: DLK1, EC, Proliferation, Angiogenesis

Abstract TMP21: Association Of A Perioperative Nausea And Vomiting Treatment Protocol With Reduction In Perioperative Strokes In Children And Young Adults With Moyamoya

Introduction: Perioperative stroke is a major complication of revascularization surgery in patients with moyamoya. Vomiting is common after neurosurgical procedures and may result in acute changes in intracranial pressure and cerebral blood flow. We instituted a standardized perioperative nausea and vomiting protocol for children and young adults with moyamoya undergoing indirect bypass surgery at our institution. Hypothesis: Instituting a standardized perioperative nausea and vomiting protocol will be associated with reduction in the number of perioperative strokes in children with moyamoya undergoing indirect bypass surgery. Methods: We retrospectively reviewed consecutive cases of children and young adults with moyamoya who underwent indirect bypass surgery before and after implementation of a new perioperative nausea and vomiting protocol. We compared the rate of strokes in the perioperative period (post-operative day 0 and 1) in the 41 months following implementation (155 surgically treated hemispheres) to 155 surgically treated hemispheres (over 30 months) prior to implementation using Fisher’s Exact test. Results: The mean age prior to implementation was 8.7 years (SD 5.5 years) and 9.9 years (SD 6.2 years) post implementation which was not significantly different (p=0.17). In the 30 months prior to initiation of the perioperative nausea and vomiting protocol there were 5 strokes in 155 surgically treated hemispheres (3.2%). After initiation of the protocol, there were no strokes in 155 surgically treated hemispheres (p = 0.03). Conclusions: Instituting a standardized perioperative nausea and vomiting protocol was associated with reduction in perioperative strokes in children with moyamoya treated with indirect bypass surgery.

Postoperative cerebral infarction after revascularization in patients with moyamoya disease: Incidence and risk factors.

Cerebral infarction is the major complication of revascularization surgery in patients with moyamoya disease (MMD), and we analyzed the possible causes of cerebral infarction after revascularization surgery for MMD. MMD patients who were admitted and underwent surgical revascularization at Shanghai Huashan Hospital from January 2019 to December 2021 were retrospectively analyzed. A total of 815 patients and 890 revascularization surgeries (677 first revascularization surgeries and 213 second revascularization surgeries) were included in this study; 453 (50.9%) were performed on the left side and 437 (49.1%) on the right side, with 779 (87.5%) combined procedures and 111 (12.5%) indirect bypasses included. The mean patient age at the time of these procedures was 44.6 ± 11.7 years (range 6-72 years). Postoperative cerebral infarctions were observed in 46 (5.17%) surgeries, among which 31 occurred after left hemisphere revascularization surgeries, with an incidence of 6.84%, and 15 occurred after right hemisphere revascularization surgeries, with an incidence of 3.43%. Of these, 30 (65.2%) occurred in the operated hemispheres, 2 (4.3%) in the contralateral hemisphere and 13 (28.3%) in the bilateral hemisphere. There were 11 cases of massive infarction (23.9%). The incidence of postoperative infarction in patients undergoing the first revascularization was 6% (41/677) and 2.3% (5/213) in the second revascularization surgeries. Initial presentation as infarction (P < 0.001), initial presentation as hemorrhage (P < 0.001), hypertension (P = 0.018), diabetes (P = 0.006), 1st or 2nd surgery and surgical side (P = 0.007) were found to be related to postoperative cerebral infarction. Initial presentation as infarction (OR = 2.934, 95% CI 1.453-5.928, P = 0.003), initial presentation as hemorrhage (OR = 0.149, 95% CI 0.035-0.641, P = 0.011), and 1st or 2nd surgery and surgical side (OR = 1.66, 95% CI 1.106-2.491, P = 0.014) were independently associated with cerebral infarction after revascularization surgeries. In patients with MMD undergoing surgical revascularization, initial presentation as infarction and first revascularization surgery performed on the left hemisphere are independent risk factors for postoperative cerebral infarction, whereas initial presentation as hemorrhage is a protective factor.

Cerebrovascular Reserve Impairment in the Anterior Cerebral Artery Territory Predicts Deep Temporal Artery Enlargement After Combined Revascularization Surgery in Moyamoya Disease.

A combined surgery of direct and indirect revascularization has been frequently performed in patients with moyamoya disease, though the efficacy of indirect revascularization surgery in adult patients with moyamoya disease has not been established. This study aimed to evaluate superficial temporal artery (STA) and deep temporal artery (DTA) diameters 1day and 3months after combined revascularization surgery in patients with moyamoya disease. We also investigated clinical factors related to DTA enlargement after surgery. We examined 78 cerebral hemispheres in 57 adult and pediatric patients with moyamoya disease who underwent combined revascularization surgery [STA-MCA bypass and encephalo-duro-myo-synangiosis] in our institution. STA and DTA diameters were measured on axial magnetic resonance angiography images at 1day and 3months after surgery. DTA diameter increased in 64 hemispheres (82.1%). DTA diameter increase in association with STA diameter decrease was found in 39 hemispheres (50%). The proportion of hemispheres with a reduction in STA diameter was significantly higher in hemispheres with DTA enlargement than in hemispheres with DTA reduction (P=0.0088). Among the 64 hemispheres with DTA enlargement, 51 (79.7%) showed cerebrovascular reserve (CVR) impairment in the anterior cerebral artery (ACA) territory before surgery. CVR impairment in the ACA territory was the only clinical factor related to DTA enlargement (P<0.001). The DTA frequently enlarges after combined revascularization surgery, even in adult patients with moyamoya disease. In patients with impaired CVR in the ACA territory, blood supply from the DTA to the ACA territory can be expected after combined revascularization surgery.

Delta-like factor 1 negatively regulates angiogenesis as a target gene of miR-126-5p after indirect revascularization surgery in patients with moyamoya disease

Promoting endothelial cell (EC) proliferation and angiogenesis after indirect revascularization surgery is crucial for decreasing the stroke rate in moyamoya patients. However, the role of delta-like factor 1 (DLK1) in regulating EC proliferation in chronically ischaemic brains and the specific mechanisms remain unclear. Therefore, we compared the expression levels of DLK1 in the dura mater (DM) tissues of patients with moyamoya disease and patients with aneurysms, and dual luciferase reporter and RNA binding protein immunoprecipitation assays were conducted to determine whether DLK1 is a target gene of miR-126-5p. The effect of DLK1 on EC proliferation and the interaction between DLK1 and miR-126-5p were explored in vitro. Then, we established an animal model of two-vessel occlusion together with encephalo-myo-synangiosis (2VO+EMS). The temporalis muscles (TMs) of the animals were transfected with DLK1 lentiviral RNA (Lv-DLK1) and short hairpin RNA (sh-DLK1) to compare the DLK1 expression, angiogenesis (CD31 count), and numbers of vacuoles and impaired tight junctions in the ECs of TM-covered chronically ischaemic brains as well as the cognitive improvement in each group. DLK1 expression was lower in the DM tissues of moyamoya patients than in those of the aneurysm patients, and DLK1 was identified as a target gene of miR-126-5p. In vitro, DLK1 inhibited EC proliferation, migration and angiogenesis and exerted effects opposite those of miR-126-5p. In 2VO+EMS rats, compared to the control transfection, the TM transfection of Lv-DLK1 induced significantly higher DLK1 expression and worse angiogenesis in the TM-covered ischaemic brain as well as less extensive cognitive improvement, while the transfection of sh-DLK1 into the TM had the opposite effects. In summary, DLK1, a target gene of miR-126-5p, negatively regulates angiogenesis in chronically ischaemic brains and is expected to be a new target to improve the efficacy of indirect revascularization surgery and the prognosis of moyamoya patients.

Symptomatic hyperperfusion after combined revascularization surgery in patients with pediatric moyamoya disease: patient series

BACKGROUNDSymptomatic hyperperfusion after cerebral revascularization for pediatric moyamoya disease (MMD) is a rare phenomenon. The authors report a series of patients with this condition.OBSERVATIONSIn all three patients in this case series, the combined revascularization was on the left side, the patency of bypass grafts was confirmed after surgery, and focal hyperemia around the anastomotic site was observed on single photon emission computed tomography (SPECT). On the first to eighth days after surgery, all of the patients developed neurological manifestations, including motor aphasia, cheiro-oral syndrome, motor weakness of their right upper limbs, and severe headaches. These symptoms disappeared completely approximately 2 weeks after surgery, and all patients were discharged from the hospital. Quantitative SPECT was performed to determine the proportional change in cerebral blood flow (ΔRCBF) (to ipsilateral cerebellar ratio (denoted ΔRCBF) in the region of interest around the anastomoses, and the mean value was 1.34 (range, 1.29–1.41).LESSONSThis rare condition, which develops soon after surgery, requires an accurate diagnosis by SPECT. One indicator is that the ΔRCBF has risen to 1.3 or higher. Subsequently, strategic blood pressure treatment and fluid management could prevent the development of hemorrhagic stroke.

Risk Factors for Surgical Site Infection After Lower Limb Revascularization Surgery in Adults With Peripheral Artery Disease: Protocol for a Systematic Review and Meta-analysis.

BackgroundSurgical site infections (SSIs) are common, costly, and associated with increased morbidity and potential mortality after lower limb revascularization surgery (ie, arterial bypass, endarterectomy, and patch angioplasty). Identifying evidence-informed risk factors for SSI in patients undergoing these surgeries is therefore important.ObjectiveThe aim of this study is to conduct a systematic review and meta-analysis of prognostic studies to identify, synthesize, and determine the certainty in the cumulative evidence associated with reported risk factors for early and delayed SSI after lower limb revascularization surgery in adults with peripheral artery disease.MethodsWe will search MEDLINE, Embase, the seven databases in Evidence-Based Medicine Reviews, review articles identified during the search, and included article bibliographies. We will include studies of adults (aged ≥18 years) with peripheral artery disease that report odds ratios, risk ratios, or hazard ratios adjusted for the presence of other risk factors or confounding variables and relating the potential risk factor of interest to the development of SSI after lower limb revascularization surgery. We will exclude studies that did not adjust for confounding, exclusively examined certain high-risk patient cohorts, or included >20% of patients who underwent surgery for indications other than peripheral artery disease. The primary outcomes will be early (in-hospital or ≤30 days) SSI and Szilagyi grade I (cellulitis involving the wound), grade II (infection involving subcutaneous tissue), and grade III (infection involving the vascular graft) SSI. Two investigators will independently extract data and evaluate the study risk of bias using the Quality in Prognosis Studies tool. Adjusted risk factor estimates with similar definitions will be pooled using DerSimonian and Laird random-effects models. Heterogeneity will be explored using stratified meta-analyses and meta-regression. Finally, we will use the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach to determine certainty in the estimates of association between reported risk factors and the development of SSI.ResultsThe protocol was registered in PROSPERO (International Prospective Register of Systematic Reviews). We will execute the peer-reviewed search strategy on June 30, 2021, and then complete the review of titles and abstracts and full-text articles by July 30, 2021, and September 15, 2021, respectively. We will complete the full-text study data extraction and risk of bias assessment by November 15, 2021. We anticipate that we will be able to submit the manuscript for peer review by January 30, 2022.ConclusionsThis study will identify, synthesize, and determine the certainty in the cumulative evidence associated with risk factors for early and delayed SSI after lower limb revascularization surgery in patients with peripheral artery disease. The results will be used to inform practice, clinical practice statements and guidelines, and subsequent research.Trial RegistrationPROSPERO International Prospective Register of Systematic Reviews CRD42021242557; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=242557International Registered Report Identifier (IRRID)PRR1-10.2196/28759

Imaging Pattern and the Mechanisms of Postoperative Infarction After Indirect Revascularization in Patients with Moyamoya Disease

To develop preventive strategies against postoperative infarction after indirect revascularization surgery in patients with moyamoya disease (MMD), we evaluated clinical information, with a specific focus on the imaging pattern of postoperative infarction. We retrospectively evaluated 421 surgical procedures performed in 354 (262 pediatric and 159 adult) patients with MMD from April 1991 to March 2021 at our institute. In addition to clinical information, raw images of postoperative infarction were collected and categorized into subtypes by the location of the infarction. Symptomatic and asymptomatic postoperative infarction occurred in 47 and 12 patients (11.1% and 2.6%), respectively, and more than half (51.7%) of these cases of postoperative infarction occurred immediately or the day after the surgery. Cortical infarction around the craniotomy site was the most frequent pattern observed (50/59, 84.8%), and some of these cases seemed to occur under local compression from epidural or subdural hematomas (15/50, 30.0%). Ipsilateral white matter infarctions located in the watershed area (9/59, 15.3%) and contralateral infarctions (3/59, 5.1%) were also observed. Four patients (1.0%) showed sudden occlusions of ipsilateral or contralateral large intracranial arteries immediately after surgery. Postoperative infarction caused permanent neurologic deficits in 7 patients (1.7%), and all included the cortex outside the craniotomy site. Local cortical irritation, hemodynamic fluctuation, and thromboembolic events were suggested as possible mechanisms of postoperative infarction after indirect revascularization in patients with MMD. Minimizing cortical irritation, maintaining adequate cerebral blood flow, and perioperative antiplatelet agents might decrease the incidence of postoperative infarction.

Cerebrovascular Reactivity Mapping Using Resting-State BOLD Functional MRI in Healthy Adults and Patients with Moyamoya Disease.

Background Cerebrovascular reserve, the potential capacity of brain tissue to receive more blood flow when needed, is a desirable marker in evaluating ischemic risk. However, current measurement methods require acetazolamide injection or hypercapnia challenge, prompting a clinical need for resting-state (RS) blood oxygen level-dependent (BOLD) functional MRI data to measure cerebrovascular reactivity (CVR). Purpose To optimize and evaluate an RS CVR MRI technique and demonstrate its relationship to neurosurgical treatment. Materials and Methods In this HIPAA-compliant study, RS BOLD functional MRI data collected in 170 healthy controls between December 2008 and September 2010 were retrospectively evaluated to identify the optimal frequency range of temporal filtering on the basis of spatial correlation with the reference standard CVR map obtained with CO2 inhalation. Next, the optimized RS method was applied in a new, prospective cohort of 50 participants with Moyamoya disease who underwent imaging between June 2014 and August 2019. Finally, CVR values were compared between brain hemispheres with and brain hemispheres without revascularization surgery by using Mann-Whitney U test. Results A total of 170 healthy controls (mean age ± standard deviation, 51 years ± 20; 105 women) and 100 brain hemispheres of 50 participants with Moyamoya disease (mean age, 41 years ± 12; 43 women) were evaluated. RS CVR maps based on a temporal filtering frequency of [0, 0.1164 Hz] yielded the highest spatial correlation (r = 0.74) with the CO2 inhalation CVR results. In patients with Moyamoya disease, 77 middle cerebral arteries (MCAs) had stenosis. RS CVR in the MCA territory was lower in the group that did not undergo surgery (n = 30) than in the group that underwent surgery (n = 47) (mean, 0.407 relative units [ru] ± 0.208 vs 0.532 ru ± 0.182, respectively; P = .006), which is corroborated with the CO2 inhalation CVR data (mean, 0.242 ru ± 0.273 vs 0.437 ru ± 0.200; P = .003). Conclusion Cerebrovascular reactivity mapping performed by using resting-state blood oxygen level-dependent functional MRI provided a task-free method to measure cerebrovascular reserve and depicted treatment effect of revascularization surgery in patients with Moyamoya disease comparable to that with the reference standard of CO2 inhalation MRI. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Wolf and Ware in this issue.