Deciphering the role of extrachromosomal circular DNA in adipose stem cells from old and young donors.

BACKGROUND: The functional impairment of adipose stem cells (ASCs) during aging limits their clinical transformation. Studies have shown that extrachromosomal circular DNAs (eccDNAs) are associated with tumor progression and cell aging, but the roles of eccDNAs in ASCs remain unknown. METHOD: We conducted Circle sequencing (Circle-seq) to identify eccDNAs in ASCs isolated from young and old donors. The differentially expressed eccDNAs were calculated, annotated and validated via polymerase chain reaction. RESULTS: Thousands of eccDNAs were identified and comprehensively characterized. Most of them were GC-rich, < 1000 base pairs in size, and were enriched on chromosome 19 and 17 with a high density of Alu elements and genes, 2 kb upstream/downstream of genes and satellites. In total, 3025 eccDNAs were differentially expressed among the two ASC groups. Conjoint analysis of the Circle-seq results and previous RNA-seq results revealed that 73 eccDNAs and 55 genes exhibited the same differential expression between the two groups. KEGG and GO analyses revealed that genes encoding differentially expressed eccDNAs were enriched for cell adhesion, cellular senescence and TGF-ß receptor signaling pathway. We also found that aged ASCs exhibited loss of eccDNAs, including CAMK2G (chr10: 75577899-75578176), TRABD2B (chr1: 48305638-48307008) and TRABD2B (chr1: 48305425-48307091). CONCLUSION: In this study, we elucidated the first eccDNA profile relating to ASCs and demonstrated that three eccDNAs are lost in aged ASCs, which may be potential biomarkers of stem cell aging and valuable targets for stem cell rejuvenation.

Visualization balloon occlusion-assisted technique in the treatment of large or giant paraclinoid aneurysms: A study of 17 cases series.

Objective: Although balloon-assisted techniques are valuable in aneurysm clipping, repeated angiography and fluoroscopy are required to understand the location and shape of the balloon. This study investigated the value of visualization balloon occlusion-assisted techniques in aneurysm hybridization procedures. Methods: We propose a visualization balloon technique that injects methylene blue into the balloon, allowing it to be well visualized under a microscope without repeated angiography. This study retrospects the medical records of 17 large or giant paraclinoid aneurysms treated by a visualization balloon occlusion-assisted technique in a hybrid operating room. Intraoperative surgical techniques, postoperative complications, and immediate and long-term angiographic findings are highlighted. Results: All 17 patients had safe and successful aneurysm clipping surgery with complete angiographic occlusion. Under the microscope, the balloon injected with methylene blue is visible through the arterial wall. The position and shape of the balloon can be monitored in real time without repeated angiography and fluoroscopic guidance. Two cases of intraoperative visualization balloon shift and slip into the aneurysm cavity were detected in time, and there were no cases of balloon misclipping or difficult removal. Of 17 patients, four patients (23.5%) experienced short-term complications, including pulmonary infection (11.8%), abducens nerve paralysis (5.9%), and thalamus hemorrhage (5.9%). The rate of vision recovery among patients with previous visual deficits was 70% (7 of 10 patients). The mean follow-up duration was 32.76 months. No aneurysms or neurological deficits recurred among all patients who completed the follow-up. Conclusion: Our study indicates that microsurgical clipping with the visualization balloon occlusion-assisted technique seems to be a safe and effective method for patients with large or giant paraclinoid aneurysms to reduce the surgical difficulty and simplify the operation process of microsurgical treatment alone.

Clinical Efficacy of Endoscopic Infratentorial Supracerebellar Approach for Pineal Region Tumors: A Retrospective Case-Control Study.

Tumors in the pineal region are deep, with complex surrounding anatomy, adjacent to important blood vessels and nerve structures, and surgical resection is difficult and risky. In this paper, we reviewed the literature to understand the epidemiology and clinical manifestations of pineal region tumors in the country and study the clinical indications, related problems, and successful experiences of patients with pineal region tumors treated by the transtentorial-superior approach. The clinical data of 80 patients with pineal region tumors were selected as the retrospective research objects and divided into the control group and the treatment group, with 40 cases in each group, according to the random number table method. The control group was treated using the endoscopic transtentorial approach (Poppen approach), while the treatment group was treated with the endoscopic supratentorial approach (Krause approach). The inflammatory factors, inflammatory stress response, postoperative neurological dysfunction, clinical efficacy, and poor prognosis were observed and compared between the two groups. Tumor resection and recurrence were used to compare the clinical outcomes of tumors in the pineal region. The extent of surgical resection was 100% higher in both groups, and the treatment group was comparable to the control group. The prognosis of patients after the operation was poor. Nausea and vomiting, visual disturbance, upper vision paralysis, and ataxia in the treatment group were significantly lower than those in the control group, with no statistical significance (P > 0.05). At the same time, the bone window can be reduced to reduce trauma and provide a certain reference for patients to choose a safe and complete resection method.

Combined Endovascular and Surgical Treatment for Brain Arteriovenous Malformations in Biplanar Hybrid Operating Room.

OBJECTIVE: Combined surgical and endovascular treatment for vascular disorders has become prevalent in recent years. However, reports on one-session hybrid surgery for arteriovenous malformations (AVMs) are relatively rare. The safety and efficiency of combined treatment for brain AVMs were analyzed in biplanar hybrid operating room (OR) at one stage. METHODS: We retrospectively analyzed 20 patients with AVMs undergoing combined surgical and endovascular treatment from October 2015 to June 2018. The data for resection rate, microcatheter adhesion, surgical position and postoperative outcomes were analyzed. Total resection or near-total resection was achieved in all cases. RESULTS: A total of 13 patients were under combined endovascular and surgical procedures, and 7 experienced surgery with intraoperative digital subtraction angiography. Sitting position was applied in 3 of them; 2 niduses in cerebellum, and 1 in parietal lobe. Compared with admission modified Rankin Scale (mRS) in all patients, postoperative 12-month mRS showed a significant decline. Besides, 3 patients experienced microcatheter adhesion after endovascular embolization, thereafter underwent surgical adhesion removal while nidus resection was done. CONCLUSION: Combined endovascular and surgical modality in a hybrid OR at one stage provides a safe strategy for the treatment of AVMs. The biplanar hybrid neurointerventional suite is endowed with unconstrained operating angle which enables combined endovascular and surgical treatment in sitting position. It also reduces the risk of microcatheter adhesion, which enables interventional radiologists to perform aggressively.

Endoscope-Assisted Microsurgery in Pediatric Cases With Pineal Region Tumors: A Study of 18 Cases Series.

Background: An endoscope-assisted technique was recently introduced to microsurgery (MS) and may compensate for the disadvantages of MS for deep-seated lesions. This study was performed to identify the effectiveness and safety of endoscopic-assisted microsurgery (EAM) and share our experience of EAM for pediatric cases with pineal region tumors. Method: We retrospectively analyzed the clinical data of consecutive pediatric cases with pineal region tumors treated by EAM or MS from January 2016 to June 2020. These data included the patient population, clinical manifestations, preoperative examination findings, surgical approach, pathological results, and clinical outcomes. The clinical outcomes were analyzed in the EAM group and MS group with a focus on the gross total resection (GTR) rate, postoperative hydrocephalus remission rate, and Karnofsky performance score (KPS). Studies on the surgical management of children with pineal region tumors in the last decade were reviewed. Result: Eighteen children successfully underwent tumor resection via MS (n = 8) or EAM (n = 10). The children's mean age was 11.4 ± 4.7 years, and the male to female ratio was 7:2. Seventeen patients (94.4%) complicated preoperative hydrocephalus, and 16 (88.9%) presented headache with nausea and/or vomiting. The pathological examination revealed germ cell tumors in 11 (61.1%) patients, neuroepithelial tumors in 4 (22.2%) patients, and a pineoblastoma, arachnoid cyst, and atypical teratoid rhabdoid tumor in 1 (5.6%) patient each. GTR was more commonly achieved in the EAM than MS group (80.0 vs. 50.0%, respectively), and the postoperative hydrocephalus remission rate was higher in the EAM than MS group (87.5 vs. 50.0%, respectively). At a mean follow-up time of 23.6 ± 11.5 weeks, the mean improvement of the KPS 6 months postoperatively was greater in the EAM than MS group (24.0 ± 9.7 vs. 17.5 ± 7.1 points, respectively). Conclusion: EAM combines endoscopic and microsurgical techniques and can be safely and effectively performed to achieve GTR of pineal region tumors in pediatric patients. In children with pineal region tumors who have obstructive hydrocephalus, EAM could improves hydrocephalus remission rates by checking and clearing the midbrain aqueduct under visualization.

Characteristics and operation outcomes of neuro-oncology patients after COVID-19 pandemic - A case series.

BACKGROUND: COVID-19 has been spreading worldwide at hitherto unknown speed, and the treatment of neuro-oncology patients without COVID-19 has been greatly affected. METHODS: To compare the medical records and surgical results of surgical patients before and after the pandemic. We collected a total of 80 patients form April 2020 to May 2020 after pandemic and from April 2019 to May 2019 before pandemic. The patient's demographics, past medical history, comorbidities, imaging, pathology, laboratory teat, and Karnofsky Performance Score (KPS) were analyzed. RESULTS: The most common presenting symptom was intracranial hypertension and neurological deficit. Hypertension and diabetes were the most common comorbid diseases. The pre-operation KPS were 83.21 ± 15.60, 80 ± 14.77, 78.57 ± 12.83 and 74.14 ± 12.72, respectively. The post-operation KPS were 94.64 ± 8.65, 95.45 ± 6.56, 91.43 ± 10.82 and 84.21 ± 22.55, respectively. The tumor volume was larger and the midline shift distance was greater after the pandemic than before. For pathological grade, meningiomas were mostly grade I, while gliomas were mainly grade III and IV. CONCLUSION: Although affected by the COVID-19 pandemic, patients with glioma should be operated as soon as possible to obtain better surgical results, however, for patients with meningiomas, their operation can be postponed slightly when the patients are tolerable.

Endoscopic-assisted surgery versus microsurgery for pineal region tumors: a single-center retrospective study.

Pineal region tumors are extremely deep-seated and surgically challenging. The exposure and visualization obtained by microscopic surgery are relatively limiting. The application of high-definition endoscopes has recently provided neurosurgeons with a much more magnified and clearer view of the anatomy in the pineal region. The present study was performed to compare endoscopic-assisted surgery (ES) with microsurgery (MS) for pineal region tumors. We retrospectively analyzed patients admitted to our hospital for treatment of pineal region tumors from January 2016 to June 2019. All patients consented to undergo tumor resection with ES or MS. We compared the extent of resection, postoperative rate of hydrocephalus, complications, and outcomes between the two groups to estimate the safety and efficacy of ES. In total, 41 patients with pineal region tumors were divided into 2 groups: the ES group (n = 20) and MS group (n = 21). The rate of gross total resection was significantly higher in the ES than MS group (90.0% vs. 57.1%, p = 0.04). The rate of postoperative hydrocephalus was significantly lower in the ES than MS group (11.8% vs. 52.9%, p = 0.03). No significant differences were found in complications or the Karnofsky Performance Score between the two groups. ES can be used to safely and effectively achieve complete resection of pineal region tumors. In patients with obstructive hydrocephalus, ES provides a new way to directly open the aqueduct for cerebrospinal fluid recovery following tumor resection.

Combined microscope and endoscopy total resection of primary pineal malignant melanoma: case report and literature review.

BACKGROUND: Primary pineal malignant melanoma (PPMM) is a rare entity of primary central nervous system melanomas, with only 26 cases reported in the literature to date. CASE PRESENTATION: We report the case of a 65-year-old male with a PPMM who has prolonged survival of more than 104 weeks after combined microsurgical and endoscopic total resection. This is the first report: combined microscope and endoscopy total resection; PPMM in China; PPMM with total resection alone. CONCLUSION: Combined microscope and endoscopy total resection is beneficial to prolong the survival of patients. But the best approach to treatment needs verification from more clinical cases in future.

Beneficial effects of (R)-ketamine, but not its metabolite (2R,6R)-hydroxynorketamine, in the depression-like phenotype, inflammatory bone markers, and bone mineral density in a chronic social defeat stress model.

Inflammatory bone markers may play a role in the antidepressant actions of (R)-ketamine in susceptible mice after chronic social defeat stress (CSDS). In this study, we compared the effects of (R)-ketamine and its final metabolite (2R,6R)-hydroxynorketamine (HNK) in depression-like phenotypes, inflammatory bone markers and bone mineral density (BMD) in CSDS susceptible mice. We measured plasma levels of inflammatory bone markers, which included osteoprotegerin (OPG), receptor activator of nuclear factor κB ligand (RANKL), and osteopontin after behavioral tests. (R)-ketamine, but not (2R,6R)-HNK, elicited rapid and sustained antidepressant effects in CSDS susceptible mice. Furthermore, (R)-ketamine, but not (2R,6R)-HNK, significantly improved the increased plasma levels of RANKL and decreased OPG/RANKL ratio in CSDS susceptible mice. Moreover, (R)-ketamine, but not (2R,6R)-HNK, significantly attenuated the decreased BMD in CSDS susceptible mice. These findings demonstrate that (R)-ketamine may have beneficial effects in depression-like phenotype and abnormalities in bone functions of CSDS susceptible mice. It is, therefore, likely that (R)-ketamine would be a potential therapeutic drug for abnormalities in bone metabolism in depressed patients.

Intracerebral hemorrhage cadaver model for training in hematoma evacuation under endoscopy.

Neuroendoscopic surgery has been performed as an effective method for intracerebral hemorrhage (ICH). This study describes the know-how of constructing the ICH cadaver model and the training on the main neuroendoscopic procedures for ICH. During the training, operation time of twenty trainees in main stages of craniotomy and corticotomy (stage 2), and hematoma evacuation under endoscopy (stage 3) was recorded. To distinguish factors influencing trainees' surgical proficiency, operation time was calculated according to seniority, experience in neuroendoscopic surgery and training sequence. Questionnaire about validity of model was conducted eventually. Ten ICH cadaver models with bilateral hematoma were constructed. Seven trainees worked with seniority >5 years and eleven had experience in neuroendoscopic surgery. Operation time ranged from 20.6 to 33.4 min in stage 2 and 18.5 to 24.9 min in stage 3. In stage 2, less operation time was needed for trainees with seniority >5 years comparing to trainees with seniority ≦5 years (22.56 ±â€¯1.29 vs 29.25 ±â€¯3.02 min, p < 0.01). In stage 3, significant difference of operation time was found between trainees with experience in neuroendoscopic surgery and trainees without the experience (20.08 ±â€¯1.22 vs 22.02 ±â€¯1.82 min, p = 0.014), and the same between trainees in latter group and in former group (19.75 ±â€¯0.80 vs 22.54 ±â€¯1.45 min, p < 0.01). Questionnaire feedback proved high degree of satisfaction about the training model. Therefore, the ICH cadaver model can assist neurosurgeons with neuroendoscopic treatment learning sessions. Simulation and improvement in neuroendoscopic surgical techniques for ICH treatment were possible with the help of ICH cadaver model.

Combined Surgical and Endovascular Treatment of a Complex Posterior Communicating Artery Aneurysm at One-Stage in a Hybrid Operating Room.

BACKGROUND: Although clipping and coiling of intracranial aneurysms are effective treatment options, they each have limitations. With the advent of the hybrid operating room, combined clipping and coiling for complex aneurysms in one stage becomes feasible. We report a successful case of a left posterior communicating artery aneurysm where combined clipping and endovascular treatment were applied. CASE DESCRIPTION: A 57-year-old man had been complaining of severe headache for 10 days. The computed tomography scan from a previous hospital revealed a parasellar lesion, and the computed tomography angiography in our hospital showed a 16-mm posterior communicating artery aneurysm. Clipping of the aneurysm was scheduled in our hybrid operating room, which enabled intervention of intraoperative digital subtraction angiography (DSA). However, once the aneurysm was clipped, intraoperative DSA revealed that the aneurysm was remnant. We readjusted the clip and reran DSA, but the residual neck was still present. In an effort to preserve the parent artery and perforators, we decided to perform endovascular treatment. Coiling was achieved, followed by angiography, indicating that the aneurysm was almost eliminated. Overall, the patient underwent 4 angiographic explorations during surgery. CONCLUSIONS: Combined open surgical and endovascular approaches to treat complex cerebral aneurysms in an hybrid operating room could offer an alternative when the aneurysms appear unclipped or remnant intraoperatively. In our experience, simultaneous clipping and coiling is a safe and effective procedure for efficient treatment of aneurysms.

Treatment of giant cavernous aneurysm in an elderly patient via extracranial-intracranial saphenous vein bypass graft in a hybrid operating room: A case report.

RATIONALE: Extracranial-intracranial saphenous vein bypass (EC-IC SVB) remains indispensable for treating giant cavernous aneurysms. We report an unusual case of a giant cavernous aneurysm in an elderly patient treated with EC-IC SVB in a hybrid operating room. Immediately following proximal ligation of the internal carotid artery (ICA), she suffered an acute intraoperative encephalocele. PATIENT CONCERNS: A 71-year-old woman had suffered from severe headache and double vision for 4 months. DIAGNOSES: The woman was diagnosed with a right giant cavernous aneurysm. INTERVENTIONS: She was treated with an EC-IC SVB with therapeutic ICA occlusion in the first biplane hybrid operating room in China. Just after proximal ligation of the ICA, she developed an acute encephalocele, and immediately underwent decompressive craniectomy. During the surgery she underwent 3 angiographic explorations. OUTCOMES: After surgery, the aneurysm disappeared, and the graft was patent. Postoperative computed tomography and computed tomography angiography indicated a cranial defect and graft patency. LESSONS: Although a hybrid operating room could improve the patency of grafts, the timing of ICA ligation for giant cavernous aneurysm via EC-IC bypass deserves further discussion. Second-stage ICA occlusion could offer an alternative for elderly patients requiring such treatment. In addition, cranial flap removal could prevent further neurologic deficits in a case of acute intraoperative encephalocele.

The Optimum Operative Time of Revascularization for Patients with Moyamoya Disease Following Acute Onset.

OBJECTIVE: Whether surgery should be performed in patients with acute onset of moyamoya disease (MMD) is controversial. This study aimed to determine optimum operative time for patients with MMD. METHODS: We retrospectively analyzed 57 patients with MMD admitted between January 2016 and June 2017. All patients consented to combined revascularization. Considering the time interval between acute onset of MMD and surgery, we divided all patients into an early group and later group (>90 days between MMD onset and surgery). We compared postoperative complications, neurologic improvement, and favorable outcome between groups to estimate optimum operative time of revascularization. RESULTS: More patients in the early group presented with ischemic events compared with the later group (18/28 vs. 11/29, P = 0.047). The difference in worst preoperative mRS score (≥3) between groups was not statistically significant (3/28 vs. 3/29, P = 0.964). Rate of postoperative complications in the early group was significantly higher than in the later group (39.2% vs. 13.7%, P = 0.029). There was neurologic improvement in 50.0% of patients in the early group and 75.9% of patients in the later group (P = 0.043). The rate of favorable outcome after revascularization in the later group (89.7%) was higher than in the early group (78.6%), but there was no significant difference (P = 0.251). CONCLUSIONS: It seems more reasonable to opt for delayed revascularization for patients with acute-onset MMD, but the decision must take into account the morbidity of ongoing ischemic or hemorrhagic events.

Treatment strategies for huge central neurocytomas.

Central neurocytomas (CNs), initially asymptomatic, sometimes become huge before detection. We described and analyzed the clinical, radiological, operational and outcome data of 13 cases of huge intraventricular CNs, and discussed the treatment strategies in this study. All huge CNs (n=13) in our study were located in bilateral lateral ventricle with diameter ≥5.0 cm and had a broad-based attachment to at least one side of the ventricle wall. All patients received craniotomy to remove the tumor through transcallosal or transcortical approach and CNs were of typical histologic and immunohistochemical features. Adjuvant therapies including conventional radiation therapy (RT) or gamma knife radiosurgery (GKRS) were also performed postoperatively. Transcallosal and transcortical approaches were used in 8 and 5 patients, respectively. Two patients died within one month after operation and 3 patients with gross total resection (GTR) were additionally given a decompressive craniectomy (DC) and/or ventriculoperitoneal shunt (VPS) as the salvage therapy. Six patients received GTR(+RT) and 7 patients received subtotal resection (STR)(+GKRS). Eight patients suffered serious complications such as hydrocephalus, paralysis and seizure after operation, and patients who underwent GTR showed worse functional outcome [less Karnofsky performance scale (KPS) scores] than those having STR(+GKRS) during the follow-up period. The clinical outcome of huge CNs seemed not to be favorable as that described in previous reports. Surgical resection for huge CNs should be meticulously considered to guarantee the maximum safety. Better results were achieved in STR(+GKRS) compared with GTR(+RT) for huge CNs, suggesting that STR(+GKRS) may be a better treatment choice. The recurrent or residual tumor can be treated with GKRS effectively.

A comparative study of intraventricular central neurocytomas and extraventricular neurocytomas.

Similar histology and clinical behavior of both intraventricular central neurocytomas (CNs) and extraventricular neurocytomas (EVNs) may argue against the idea that EVNs were the distinct entity to distinguish from CNs in the 2007 World Health Organization classification. To explore respective characteristics and compare similarities and differences in CNs and EVNs, relevant clinical, radiological, operative and pathological data of 49 patients (35 CNs and 14 EVNs) in the Department of Neurosurgery at our hospital from 2005 to 2012 was reviewed and some comparisons between CNs and EVNs were conducted. The factors affecting posttreatment recurrence of CNs and EVNs were assessed by Cox regression analysis. In comparison, CNs showed a more typical clinical manifestation, and radiological and histopathological features, while EVNs demonstrated more malignant biological behavior, with higher MIB-1 index (p = 0.006), higher rate of atypia (p = 0.042), higher recurrence rate (p = 0.028), and shorter time to recurrence (p = 0.049). Subtotal resection was associated with higher rates of recurrence in both CNs (hazard ratio [HR] 6.16, p = 0.046) and EVNs (HR 5.26, p = 0.045), and atypia was also associated with a higher recurrence rate in CNs (HR 5.03, p = 0.042). CNs were thus easier to diagnose than EVNs, with typical clinical, radiological, and histopathological features, while the latter were more likely to show malignant biological behavior associated with atypia and recurrence. Total surgical resection is the optimal treatment choice for both CNs and EVNs, and patients with either CN or EVN with typical and/or totally resected lesions showed favorable clinical outcomes.

A treatment option for severe cerebellar hemorrhage with ventricular extension in elderly patients: intraventricular fibrinolysis.

External ventricular drainage (EVD) combined with intraventricular fibrinolysis (IVF) is rarely used in severe spontaneous cerebellar hemorrhage (SCH) with intraventricular hemorrhage (IVH). Recently, the treatment strategy was repeatedly performed in our hospital to elderly patients with severe SCH + IVH. To analyze its clinical value, we compared it to two treatment strategies which now commonly are used for these patients: conservative management (CM) and clot evacuation (CE). In this study, a total of 118 cases were observed, of which 28 cases received CM, 43 cases received EVD + IVF and 47 cases received CE. The Glasgow Coma Scale score, frequency of complication, mortality in one month, modified Rankin Scale (mRS) at six months, and causes of death were analyzed. The outcomes of patients in the CM group were extremely poor compared to patients undergoing surgery (P = 0.034) and the mortality was up to 61.3 % (18/28), which was much higher than those of the two surgical groups (P = 0.026). No significant difference was found in mortality and mRS between the two surgical groups (P > 0.05). Patients in the CE group mostly died of deterioration of comorbidities and postoperative complications, whereas more deaths occurred in the CM group and the EVD + IVF group due to rebleeding, brainstem compression, perilesional edema and tight posterior fossa (χ (2), P = 0.006). It is suggested that EVD + IVF is a treatment option for elderly patients with severe SCH + IVH.

Perfusion-weighted magnetic resonance imaging used in assessing hemodynamics following superficial temporal artery-middle cerebral artery bypass in patients with Moyamoya disease.

BACKGROUND: The best strategy to assess the changes in brain hemodynamics following superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in patients with Moyamoya disease remains unknown. The purpose of the present study was to assess cerebral hemodynamics using perfusion-weighted magnetic resonance imaging (PWI) before and after STA-MCA bypass surgery in patients with Moyamoya disease. METHODS: STA-MCA bypass surgeries were performed on 23 symptomatic cerebral hemispheres in 21 patients (11 females/10 males, age 11-62 years) with Moyamoya disease due to cerebral ischemic attacks or intracranial hemorrhages. Brain PWI images were obtained in the frontal lobes, the temporal lobes, the occipital lobes, and the basal ganglia before and after STA-MCA bypass surgery. The relative parameters cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) derived from PWI were calculated. All patients underwent CT angiography or MR angiography after surgery in order to confirm the patency of bypass. RESULTS: According to preoperative PWI, there was significant hypoperfusion in the symptomatic temporal and frontal lobes. According to postoperative PWI, the regional CBF had increased in both the temporal and frontal lobes on the operative side (p < 0.05, versus preoperative data). In the postoperative CBV maps, there was a significant decrease in the occipital lobe on the operative side (p < 0.05, versus preoperative data). The postoperative MTT in the temporal lobe, frontal lobe and basal ganglia area on the operative side was short, relative to the preoperative MTT (p < 0.05). The CT angiography or MR angiography imaging demonstrated patency of the bypass in all patients after surgery. During the follow-up period, all patients showed significant improvement in neurological function postoperatively. CONCLUSIONS: This study demonstrates that STA-MCA bypass is a safe and effective surgical treatment for Moyamoya disease. PWI enables an effective and objective assessment of hemodynamics before and after STA-MCA bypass surgery in patients with Moyamoya disease.