The surgical strategy and technical nuances of in situ side-to-side bypass for the management of complex intracranial aneurysms.

Background: Despite continuous advances in microsurgical and endovascular techniques, the treatment of complex aneurysms remains challenging. Aneurysms that are dilemmatic for conventional clipping or endovascular coiling often require bypass as part of a strategy to reduce the risk of ischemic complications. In anatomically favorable sites, the intracranial-intracranial in situ bypass may be an appealing choice. This article details the surgical strategies, operative nuances, and clinical outcomes of this technique with a consecutive series in our department. Methods: A retrospective review of a prospectively maintained neurosurgical patient database was performed to identify all patients treated with side-to-side in situ bypass from January 2016 to June 2022. In total, 12 consecutive patients, including 12 aneurysms, were identified and included in the series. The medical records, surgical videos, neuroimaging studies, and follow-up clinic notes were reviewed for every patient. Results: Of the 12 aneurysms, there were 5 middle cerebral artery aneurysms, 4 anterior cerebral artery aneurysms, and 3 posterior inferior cerebellar artery aneurysms. The morphology of the aneurysms was fusiform in 8 patients and saccular in the remaining 4 patients. There were 3 patients presented with subarachnoid hemorrhage. The treatment modality was simple in situ bypass in 8 cases and in situ bypass combined with other modalities in 4 cases. Bypass patency was confirmed in all cases by intraoperative micro-doppler probe and (or) infrared indocyanine green (ICG) video angiography intraoperatively and with digital subtraction angiography (DSA) or computed tomography angiography (CTA) postoperatively. None of the patients developed a clinically manifested stroke due to the procedure though a callosomarginal artery was intentionally removed in one patient. The median follow-up period was 16.2 months (6-36). All patients had achieved improved or unchanged modified Rankin scale scores at the final follow-ups. Conclusion: Cerebral revascularization technique remains an essential skill for the treatment of complex aneurysms. The in situ bypass is one of the most effective techniques to revascularize efferent territory when vital artery sacrifice or occlusion is unavoidable. The configuration of in situ bypass should be carefully tailored to each case, with consideration of variations in anatomy and pathology of the complex aneurysms.

[Treatment outcome of laparoscopic partial nephrectomy in patients with renal tumors of moderate to high complexity].

OBJECTIVE: To investigate the treatment outcome of laparoscopic partial nephrectomy in the patients with renal tumors of moderate to high complexity (R.E.N.A.L. score 7-10). METHODS: In the study, 186 patients with a renal score of 7-10 renal tumors who underwent laparoscopic partial nephrectomy in Peking University Third Hospital from February 2016 to April 2021 were selected. Laparoscopic partial nephrectomy was performed after examination. The patients were followed-up, and their postoperative hemoglobin, creatinine, complications, and length of hospital stay recorded. The data were represented by mean±standard deviation or median (range). RESULTS: There were 128 males and 58 females in this group, aged (54.6±12.8) years, with body mass index of (25.4 ± 3.4) kg/m2; The tumors were located in 95 cases on the left and 91 cases on the right, with maximum diameter of (3.1±1.2) cm. The patient's preoperative hemoglobin was (142.9±15.8) g/L, and blood creatinine was 78 µmol/L (47-149 µmol/L). According to preoperative CT images, the R.E.N.A.L. score was 7 points for 43 cases, 8 points for 67 cases, 9 points for 53 cases, and 10 points for 23 cases. All the ope-rations were successfully completed, with 12 cases converted to open surgery. The operation time was 150 minutes (69-403 minutes), the warm ischemic time was 25 minutes (3-60 minutes), and the blood loss was 30 mL (5-1 500 mL). There were 9 cases of blood transfusions, with a transfusion volume of 800 mL (200-1 200 mL). Postoperative hemoglobin was (126.2±17.0) g/L. The preoperative crea-tinine was 78 µmol/L (47-149 µmol/L), the postoperative creatinine was 83.5 µmol/L (35-236 µmol/L), the hospital stay was 6 days (3-26 days), and surgical results achieved "the trifecta" in 87 cases (46.8%). In the study, 167 cases were followed up for 12 months (1-62 months), including 1 case with recurrence and metastasis, 4 cases with metastasis, and 2 cases with other tumors (1 case died). CONCLUSION: Laparoscopic partial nephrectomy is safe and effective in the treatment of renal tumors with R.E.N.A.L. score of 7-10. Based on the complexity of the tumor, with the increase of difficulty, the warm ischemia time and operation time tend to increase gradually, while "the trifecta" rate gradually decreases. The complications of this operation are less, and the purpose of preserving renal function to the greatest extent is achieved.

New-onset lesions on MRI-DWI and cerebral blood flow changes on 3D-pCASL after carotid artery stenting.

This study aimed to investigate the relationship between the new-onset hyperintense lesions on diffusion-weighted images (DWI) and the changes of cerebral blood flow (CBF) before and after carotid artery stenting (CAS) in patients with symptomatic unilateral carotid artery stenosis. Twenty-four patients with symptomatic unilateral carotid stenosis (50-99%) were enrolled. Routine head magnetic resonance imaging and three-dimensional pseudo-continuous arterial spin labeling were taken 7 days before the surgery and for four consecutive days post CAS. While the incidence of new DWI lesions were high (17/24, 70.8%) and 176 lesions were observed among the 17 cases, there was only one subject showing the symptoms. The majority of the lesions were located at the cortex/subcortex of the ipsilateral frontal and parietal lobes (60.8%) with 92.6% of the lesions size being less than 3 mm. The CBFs in this area were significantly higher than that of the temporal lobe on the first 3 days post stenting (p < 0.05). No periprocedural CBF differences were observed between the two groups, however, the micro-embolism group presented decreased relative CBF in frontal and parietal lobes prior to stenting compared with the non-embolism group. The systolic blood pressure in the micro-embolism group at discharge was significantly lower than that at admission. The high incidence rate of micro-embolism in patients receiving CAS may not be the result of direct changes of hemodynamics in the brain but rather the loss of CBF regulation due to long-term hypoperfusion prior to the stenting.

A Supplemental Technique for Preoperative Evaluation of Giant Intracranial Aneurysm.

BACKGROUND: Preoperative planning mainly relies on digital subtraction angiography (DSA) and computed tomography angiography. However, neither technique can reveal thrombi in giant intracranial aneurysms (GIAs). In this study, we aimed to reconstruct the circulating and noncirculating parts of GIAs with the time-of-flight (TOF) and motion-sensitized driven-equilibrium (MSDE) sequences with 3D Slicer to reveal an integrated presentation of GIAs, compare its accuracy, and validate the usefulness for preoperative planning. MATERIAL AND METHODS: Patients with GIAs who were treated with microsurgery in our department were included in this study. Both the TOF and MSDE sequence data for each patient were loaded into 3D Slicer for reconstruction and segmentation. The parameters measured by 3D Slicer were compared with those measured by DSA. RESULTS: The mean diameter for all GIAs was 28.7 ± 1.5 mm (range, 25.9-31.9 mm). The mean diameter for all GIAs measured by DSA and 3D Slicer was 24.46 ± 5.25 and 28.66 ± 1.48 mm, respectively (t = 4.948, p < 0.01). When only the nonthrombotic GIAs were included, the mean diameter measured by DSA and 3D Slicer was 28.69 ± 2.03 and 28.97 ± 1.79 mm, respectively (t = 1.023, p = 0.323). The mean aneurysmal volume was 8,292.6 ± 1,175.1 mm3 and the mean thrombotic volume was 3,590.0 ± 1,003.7 mm3. CONCLUSION: The MSDE sequence brings diagnostic benefits as a comparison to other MRI sequences. Reconstruction of GIAs with 3D Slicer is a low-cost, dependable, and useful supplemental technique for surgical planning.

Identification of risk factors for poor language outcome in surgical resection of glioma involving the arcuate fasciculus: an observational study.

The arcuate fasciculus is a critical component of the neural substrate of human language function. Surgical resection of glioma adjacent to the arcuate fasciculus likely damages this region. In this study, we evaluated the outcome of surgical resection of glioma adjacent to the arcuate fasciculus under the guidance of magnetic resonance imaging and diffusion tensor imaging, and we aimed to identify the risk factors for postoperative linguistic deficit. In total, 54 patients with primary glioma adjacent to the arcuate fasciculus were included in this observational study. These patients comprised 38 men and 16 women (aged 43 ± 11 years). All patients underwent surgical resenction of glioma under the guidance of magnetic resonance imaging and diffusion tensor imaging. Intraoperative images were updated when necessary for further resection. The gross total resection rate of the 54 patients increased from 38.9% to 70.4% by intraoperative magnetic resonance imaging. Preoperative language function and glioma-to-arcuate fasciculus distance were associated with poor language outcome. Multivariable logistic regression analyses showed that glioma-to-arcuate fasciculus distance was the major independent risk factor for poor outcome. The cutoff point of glioma-to-arcuate fasciculus distance for poor outcome was 3.2 mm. These findings suggest that intraoperative magnetic resonance imaging combined with diffusion tensor imaging of the arcuate fasciculus can help optimize tumor resection and result in the least damage to the arcuate fasciculus. Notably, glioma-to-arcuate fasciculus distance is a key independent risk factor for poor postoperative language outcome. This study was approved by the Ethics Committee of the Chinese PLA General Hospital, China (approval No. S2014-096-01) on October 11, 2014.

The Special Considerations in the Surgical Management of Proximal Anterior Cerebral Artery Aneurysms.

BACKGROUND: Proximal anterior cerebral artery (A1) aneurysms are difficult to clip because of their frequent proximity to perforators, location behind the parent artery, or adherence to surrounding structures. METHODS: We retrospectively reviewed a consecutive series of patients with A1 aneurysms and report the clinical status, radiologic findings, treatment methods, and outcome. RESULTS: This series included 19 male and 12 female patients with a mean age of 50 years. The morphology of the A1 aneurysms was fusiform in 2 patients and saccular in the remaining 29 patients. Multiple aneurysms were presented in 9 patients (29.0%). On admission, 26 patients (83.9%) presented with subarachnoid hemorrhage, 3 of whom had an additional intracerebral hematoma. All surgeries were performed with a standard pteriomal craniotomy. The mean Glasgow Outcome Scale score at final follow-up was 4.8 (interquartile range, 5, 5), with 26 patients (83.9%) rated as 5. The mean follow-up time was 38.5 months (range, 12-60 months). CONCLUSIONS: A1 aneurysms are rare but have their own complex characteristics and are difficult to treat. Meticulous analysis of the relevant angiographs is needed for their diagnosis. An important consideration in surgery is the preservation of perforators and prevention of rupture. Wide opening of the sylvian fissure and temporary control of the parent artery can facilitate dissection of the A1 aneurysms dome. Multiple intraoperative monitoring methods, such as microvascular Doppler ultrasonography and somatosensory and motor evoked potential monitoring, can reduce the relevant complications of surgery.

Anterior interhemispheric approach for removing large sellar region tumor.

The aim of the study was to explore anterior interhemispheric approach microsurgery for removing large sellar region tumors.A total of 118 patients with large sellar region tumors were treated with the anterior interhemispheric approach microsurgery. There were 58 craniopharyngioma, 37 pituitary adenoma, 5 hypothalamic glioma, 7 meningioma, and 11 other tumors cases. The maximal tumor diameter ranged from 3.0 to 8.2 cm, with a mean diameter of 4.3 cm. Diabetes insipidus and fluid and electrolyte imbalance were timely controlled after surgery. Postoperative examination of endocrine and of magnetic resonance imaging (MRI) enhancement scanning of the head were performed.Total, subtotal, and partial removal of tumors was, respectively, achieved in 80, 23, and 15 cases. A total of 109 patients had improved vision after surgery. During the hospital stay, 81 had diabetes insipidus, 68 had fluid and electrolyte imbalance, and 9 had hemorrhage and tumidness in the right frontal lobe (3 had frontal lobe contusion, and 6 had frontal lobe hematoma). The postoperative follow-up visit lasted for 3 to 105 months. During the follow-up period, 14 patients had recurrence of tumors, 38 cases had their single or multiple pituitary axis treated with hormonal replacement therapy for a long time after surgery, and 23 cases had to orally take drugs for the purpose of controlling diabetes insipidus.The anterior interhemispheric approach microsurgery is feasible for removing large sellar region tumors without significant sequels. Active postoperative managements of diabetes insipidus and fluid and electrolyte imbalance may help patients with earlier recovery.

Treatment Strategies for Intracranial Mirror Aneurysms.

OBJECTIVE: Intracranial mirror aneurysms are clinically rare and uncommonly reported in the literature. Therefore, the present study evaluated a series of mirror aneurysm cases with respect to the clinical features of the patients and the treatment strategies that were used. METHODS: This study retrospectively reviewed and systematically analyzed the clinical features, imaging data, treatment methods, and treatment outcomes of 68 cases of mirror aneurysms (a total of 70 pairs) in patients who were admitted to our department between November 2007 and May 2016. RESULTS: The patient population included 24 male and 44 female patients, with a mean age of 52 years. The mirror aneurysms were primarily located in posterior communicating artery and middle cerebral artery and 65 of the aneurysms were large or giant (≧10 mm). Of the 68 patients, 28 were treated by the clipping or embolization of all aneurysms in one stage, 16 were treated in 2 stages, 16 were treated by treating part of the aneurysms, and 8 were observed. The modified Rankin Scale scores of the 60 patients that were treated indicated that 52 had a good recovery (modified Rankin Scale score ≦2; 86.7%), and 1 patient died. CONCLUSIONS: Treatment strategies for mirror aneurysms should be determined individually according to the location, size, and morphology of the aneurysm, as well as the clinical manifestations of each patient. Furthermore, the responsible ruptured aneurysm should be given treatment priority, whereas the contralateral unruptured aneurysm should be observed or treated in either 1 or 2 stages.

Surgical management of recurrent aneurysms after coiling treatment.

OBJECTIVE: Aneurysms that recur after coiling treatment are difficult to manage. The microsurgical technique in these cases differs significantly from that in regular aneurysm clipping. We present our experience in surgical management of aneurysms that recurred more than 1 month after coiling in a series of 19 patients. MATERIALS AND METHODS: Between January 2004 and December 2014, 1437 patients were treated surgically for intracranial aneurysms in our institution. We performed a retrospective review of the clinical records, operation videos, and cerebral angiograms. We focused on patients in whom the initial aneurysm was treated by coiling, but the results were incomplete or the aneurysm recurred. RESULTS: Nineteen patients underwent surgical clipping for recurrent aneurysm more than 1 month after initial coiling treatment. The sex ratio (male:female) was 0.9, and the average age was 51.3 years (range 35-72 years). One aneurysm was classified as giant (≥ 25 mm), two as large (10-25 mm), and 18 as small (≤ 10 mm). A good outcome (Glasgow Outcome Scale 4 or 5) was observed in 16 of 19 patients (84.2%). CONCLUSION: Microsurgical clipping can be safe and effective in the management of previously coiled residual and recurrent aneurysms.

[Surgical management of proximal anterior cerebral artery (A1) aneurysms].

OBJECTIVE: To review our experience in surgical management of proximal anterior cerebral artery (A1) aneurysms in 23 patients. METHODS: Between January, 2004 and December, 2014, 23 patients (1.6%) with A1 aneurysms diagnosed by CTA or DSA were treated surgically. The "3H" therapy was adopted for postoperative prevention of cerebrovascular spasm. All the patients were followed up and examined with cerebrovascular CTA at 6, 12, 48 and 60 months after the operation with their Glasgow Outcome Scale score recorded. RESULTS: The patients consisted of 15 men and 8 women with an age range of 16 to 72 years (mean 51.3 years). The average diameter of the aneurysms was 5.8 mm, ranging from 3.2 to 9.7 mm. Twenty-two saccular aneurysms were found in these patients; 21 patients presented with SAH and two had vascular malformation. All the A1 aneurysms were managed through the pterional approach, and the mean postoperative Glasgow Outcome Scale score was 4.8. CONCLUSION: Thorough analysis of the angiographic data is essential for the diagnosis and treatment of A1 aneurysms. Preservation of the perforators and prevention of aneurysm rupture are critical during the surgery. Full exposure of the Sylvian fissure and temporary occlusion of the parent artery ensures safe and effective dissection of A1 aneurysms.

The Management of Symptomatic Cerebral Developmental Venous Anomalies: A Clinical Experience of 43 Cases.

BACKGROUND Developmental venous anomalies (DVAs) are rare vascular diseases becoming more frequently diagnosed. Most patients with DVAs have no clinical symptoms with the exception of a few patients with epilepsy, intracranial hemorrhage, or neuro-function deficit. There is still controversy with respect to treatment strategies for symptomatic DVAs. MATERIAL AND METHODS Forty-three cases of symptomatic DVAs from January 2006 to October 2015 were retrospectively reviewed and the imaging characteristics of DVAs by CT, MRI, and DSA and the treatment modalities for DVAs were studied. RESULTS Typical imaging characteristics of symptomatic DVAs were wedge or umbrella-shaped collections of dilated medullary veins converging in an enlarged subependymal or transcortical collecting vein, draining to the superficial or deep vein system. Based on location and draining vein features, symptomatic DVAs were tentatively classified into six different subtypes. Of the 43 cases, 19 were treated by surgical methods and 24 were treated conservatively. CONCLUSIONS We concluded that the rate of accompanying abnormalities in cases of symptomatic DVAs was high. Intracerebral hemorrhage was usually attributed to associated CMs or AVMs. The associated lesions and the branches responsible for bleeding could be resected while preserving the collecting vein as far as possible.

Intraoperative high-field MRI maximizes the extent of resection in intraventricular central neurocytoma surgery.

Central neurocytoma (CN) is a rare benign neuronal tumor of the ventricular system. Microsurgical resection is considered to be the mainstay of treatment for intraventricular CN, and the extent of resection is the most important prognostic factor. We describe our initial experience in the management of intraventricular CN with intraoperative MRI together with microscope-based neuronavigation. During a 5year period between February 2009 and June 2014, 18 consecutive patients with histologically proven CN were included in this study. Gross total tumor resection was achieved in 88.9% (16/18) of patients. There were no perioperative deaths, and the overall complication rate was 61.1% (11/18). The Karnofsky Performance Status score at the last follow-up was 100 in eight (44.4%), 90 in seven (38.9%), and ⩽70 in three patients (16.7%). We conclude that intraoperative high-field MRI combined with microscope-based neuronavigation can maximize the extent of resection in intraventricular CN surgery and minimize the risks of neurological impairment.

Electrical stimulation of the vagus nerve protects against cerebral ischemic injury through an anti-infammatory mechanism.

Vagus nerve stimulation exerts protective effects against ischemic brain injury; however, the underlying mechanisms remain unclear. In this study, a rat model of focal cerebral ischemia was established using the occlusion method, and the right vagus nerve was given electrical stimulation (constant current of 0.5 mA; pulse width, 0.5 ms; frequency, 20 Hz; duration, 30 seconds; every 5 minutes for a total of 60 minutes) 30 minutes, 12 hours, and 1, 2, 3, 7 and 14 days after surgery. Electrical stimulation of the vagus nerve substantially reduced infarct volume, improved neurological function, and decreased the expression levels of tumor necrosis factor-α and interleukin-6 in rats with focal cerebral ischemia. The experimental findings indicate that the neuroprotective effect of vagus nerve stimulation following cerebral ischemia may be associated with the inhibition of tumor necrosis factor-α and interleukin-6 expression.

Role and mechanism of Sophoridine on proliferation inhibition in human glioma U87MG cell line.

Sophoridine, a natural product obtained from medicinal plants, which has a variety of pharmacological effects, including anti-cancer effects, and selectively induces apoptotic cell death in a variety of human cancer cells in vitro and in vivo; however, its mechanism of action needs to be further elaborated. In this study, we investigated the effects of Sophoridine on the induction of apoptosis in human Glioma U87MG cells. Here, we found that Sophoridine can significantly inhibited cell proliferation, G2/M phase arrest, induced cell apoptosis and caused reactive oxygen species (ROS) generation and GSH content reduction. Sophoridine also triggered significant down-regulated the expression of p27, CDK2, Survivin, Livin, Bcl-2, E2F1 and the transcriptional activity of FoxM1, NF-κb and AP-1, meanwhile, up-regulated the expression of caspase-3/8, p53, Smac, c-JNK and p38-MAPK. Moreover, we found that Sophoridine significantly inhibited ubiquitin-proteasome in tumor cells. In conclusion, Sophoridine shows obvious anti-cancer activity on glioma cells by inducing cell apoptosis, inducing ROS accumulation, and activating mitochondrial signal pathways. Eventually, we believe Sophoridine could be used as a new drug for the treatment of glioma.

Microsurgical management of posterior cerebral artery aneurysms: A report of thirty cases in modern era.

OBJECTIVE: We reviewed a series of 30 cases of posterior cerebral artery (PCA) aneurysms to examine the outcomes of microsurgical techniques, which is an important alternative to endovascular interventions in localities where access to the latter renders practical difficulty. We also aimed to introduce the initial experience about the clinical application of intraoperative computed tomography (CT) in treatment of PCA aneurysm. METHODS: Thirty patients with PCA aneurysm treated using microsurgery in our department between January 1996 and July 2014 were reviewed retrospectively. RESULTS: The case series included 13 females and 17 males with a mean age of 44 years, ranging from 8 to 78 years. Eighteen aneurysms were ruptured, five aneurysms caused a direct mass effect, and the remaining seven aneurysms were found incidentally. Most aneurysms were located in the P1 segment or the P1-P2 junction of the PCA (63%). Eighteen aneurysms (60%) were large or giant in size (≥ 10 mm). Seventeen aneurysms were directly clipped, six trapped, one wrapped, one electrocoagulated and resected, and five trapped or proximal clipped with a bypass. Intraoperative perfusion CT (PCT) and CT angiography (CTA) were applied to provide immediate information regarding cerebral hemodynamics and anatomy of vessels in six patients. Twenty-six patients (87%) showed good clinical outcomes according to the modified Rankin Scale score (≤ 2) at the mean clinical follow-up period of 34 (range: 1-78) months, including the patients using intraoperative CT, and one (3%) patient was dead. CONCLUSION: Microsurgical therapy for patients with PCA aneurysms can have a positive outcome with correctly selected techniques. Personalized microsurgical treatment paradigms are determined by the anatomical location, shape and size of the PCA aneurysm, and the clinical features of the patient. Intraoperative PCT and CTA can improve the efficacy of the surgical treatment.

[Surgical management of intracranial mirror aneurysms].

OBJECTIVE: To study the clinical characteristics and treatment strategies of mirror aneurysms. METHODS: Nineteen patients with 20 pairs of mirror aneurysms from November 2007 to November 2012 were retrospectively analysed. Among the 19 patients, 13 were female and 6 were male, mean age was 56 years (ranged 32-75 years). Distribution of the lesions included 11 bilateral posterior communicating artery aneurysms (one with a pair of anterior choroidal artery aneurysm), 4 bilateral middle cerebral artery aneurysms, 3 bilateral paraclinoidal aneurysms, and 1 bilateral pericallosal-callosomarginal artery aneurysm. Surgical strategies were selected according to location of hemorrhage, Hunt-Hess grade, location and size of aneurysm, etc. RESULTS: Four mirror aneurysms were clipped at one stage, 3 mirror aneurysms were clipped at two stages, 2 were treated with combination of clipping and coiling and remaining 10 were clipped unilaterally. At discharge, 15 out of 19 patients had a Glasgow Outcome Scale score of 5, 4 patients had a score of 4. The mean clinical follow-up was 18.6 months (range 3-50 months). Two patients had oculomotor nerve palsy postoperatively. At 3-month follow-up, 1 improved and 1 unchanged. In 10 patients with unilateral clipping, contralateral aneurysms were unruptured, small ( < 5 mm) and regular. No remnant or recurrence of aneurysm were found in other 9 patients whose bilateral aneurysms had been treated. CONCLUSIONS: The mirror aneurysms are rare kinds of multiple aneurysms. The aneurysm responsible for hemorrhage should be treated with first priority. The contralateral unruptured aneurysm could be observed, clipped or coiled in one stage, or treated in two separate stages.

[Microsurgery assisted by intraoperative magnetic resonance imaging and neuronavigation for small lesions in deep brain].

OBJECTIVE: To explore the practicability of resecting small lesions in deep brain by intraoperative magnetic resonance imaging (iMRI) and neuronavigator-assisted microsurgery and its clinical efficacies. METHODS: A total of 42 cases with small lesions in deep brain underwent intraoperative MRI and neuronavigator-assisted microsurgery. The drifting of neuronavigation was corrected by images acquired from intraoperative MR rescanning. RESULTS: All lesions were successfully identified and 40 cases totally removed without mortality. Only 3 cases developed new neurological deficits post-operatively while 2 of them returned to normal neurological functions after a follow-up duration of 3 months to 2 years. CONCLUSION: The application of intraoperative MRI can effectively correct the drifting of neuronavigation and enhance the accuracy of microsurgical neuronavigation for small lesions in deep brain.

Different treatment modalities of fusiform basilar trunk aneurysm: study on computational hemodynamics.

BACKGROUND: Unclippable fusiform basilar trunk aneurysm is a formidable condition for surgical treatment. The aim of this study was to establish a computational model and to investigate the hemodynamic characteristics in a fusiform basilar trunk aneurysm. METHODS: The three-dimensional digital model of a fusiform basilar trunk aneurysm was constructed using MIMICS, ANSYS and CFX software. Different hemodynamic modalities and border conditions were assigned to the model. Thirty points were selected randomly on the wall and within the aneurysm. Wall total pressure (WTP), wall shear stress (WSS), and blood flow velocity of each point were calculated and hemodynamic status was compared between different modalities. RESULTS: The quantitative average values of the 30 points on the wall and within the aneurysm were obtained by computational calculation point by point. The velocity and WSS in modalities A and B were different from those of the remaining 5 modalities; and the WTP in modalities A, E and F were higher than those of the remaining 4 modalities. CONCLUSIONS: The digital model of a fusiform basilar artery aneurysm is feasible and reliable. This model could provide some important information to clinical treatment options.

Revascularization for complex cerebral aneurysms.

BACKGROUND AND PURPOSE: Complex cerebral aneurysms may require indirect treatment with revascularization. This manuscript describes various surgical revascularization techniques together with clinical outcomes. METHODS: Thirty-two consecutive patients with complex cerebral aneurysm were managed from November 2005 to October 2008. Techniques used for revascularization were high-flow bypass, low-flow bypass, branch artery reimplantion, and primary reanastomosis. Physiologic and anatomic monitoring technologies, including electroencephalography, somatosensory evoked potential monitoring, microvascular doppler ultrasonography, and/or indocyanine green videoangiography were used intraoperatively to assess both brain physiology and vascular anatomy. Patient outcome was determined using the Glasgow Outcome Scale at discharge and at a mean of 12 months post operation (range 6-25 months). RESULTS: Two cervical carotid aneurysms (6%) were resected followed by primary reanastomosis, 21 aneurysms (66%) were trapped following saphenous vein high-flow bypasses, five (16%) were clipped after superficial temporal or occipital artery low-flow bypasses, and four (12%) middle cerebral branch arteries were reimplanted. Of the 32 patients at discharge, 29 (91%) had a Glasgow Outcome Scale of four or five, two (6%) had severe disability, and one (3%) died. CONCLUSION: Cerebral revascularization remains an effective and reliable procedure for treatment of complex cerebral aneurysms. Low morbidity and mortality rates reflect the maturity of patient selection and surgical technique in the management of these lesions.