Angiographic and clinical outcomes of various techniques of intracranial-to-intracranial bypasses for complex cases with a review of pertinent literature and illustrated cases.

OBJECTIVE: Determine the utility of intracranial-to-intracranial bypass (IIB) surgery for complex cases and bypass options. METHODS: Eighteen IIB cases were included. Each case was classified as IIB with interposition grafts and non-interposition grafts. Clinical and angiographical status were evaluated pre- and postoperatively and at the last follow-up. Angiographic images were analyzed and schematically drawn. Postoperative angiography was used to measure the bypass patency and the presence of postoperative cerebral infarction. Recipient artery occlusion time of each bypass was measured. RESULTS: 14 cases were complex intracranial aneurysms (IAs), 1 case was vertebrobasilar dolichoectasia, and 3 cases were intracranial arterial steno-occlusive disease (ICAS). 10 patients had incidental discovered IAs, and 7 patients presented with neurological deficits due to ischemia or aneurysmal mass effects. 10 cases were IIB with interposition grafts, including 4 cases of superficial temporal artery (STA) and 6 cases of radial artery graft (RAG) bypass. Eight cases were IIB with non-interposition grafts, including 3 cases of in situ bypass, 1 case of reanastomosis, and 4 cases of reimplantation. The pre- and postoperative mRS were not changed or improved, and all the bypasses were patent. There was no mortality during the mean follow-up period of 50.0 months. Mean occlusion time of recipient artery was 59.5 min. Total 8 patients had postoperative cerebral infarction but almost recovered at the discharge period. CONCLUSIONS: With the proper selection of the IIB type, IIB surgery can be a suitable treatment option for some patients with complex IAs and ICAS when extracranial-to-intracranial bypass is not feasible.

Is it safe to discontinue antiplatelet medication after stent-assisted coil embolization? If so, when is the best time?

PURPOSE: Antiplatelet maintenance after stent-assisted coil embolization (SACE) is generally considered essential to avoid post-procedural thromboembolic complications. However, there is still debate as to whether it is safe to discontinue antiplatelet drugs after SACE or when is the best time to do so. We investigate herein the clinical outcomes experienced by patients who discontinue antiplatelet agents after SACE. METHODS: From a prospective database, we retrieved the data for 120 consecutive patients (harboring 130 aneurysms) in whom antiplatelet agents were discontinued after SACE between January 2010 and December 2019. We defined thromboembolic complications associated with discontinuation as neurologic or radiographic ischemia that occurred within 6 months of discontinuation of antiplatelet agents; the lesion was required to be correlated with the stented artery. RESULTS: The mean time of discontinuation of antiplatelet medication was 31.4 ± 18.3 months after SACE (median, 26 months). The majority of patients stopped antiplatelet medication between 18 and 36 months after SACE (74 patients, 61.6%). Laser-cut closed-cell stent was most commonly applied in 91 aneurysms (70.0%), followed by braided closed-cell (n=29; 22.3 %) and laser-cut open-cell stent 10 (7.7 %). No patients experienced cerebral ischemia related to discontinuation of antiplatelet medication. CONCLUSION: Our preliminary study suggests that it may be safe to discontinue antiplatelet medication after SACE in patients at low risk for ischemia. The optimal time to discontinue might be around 18 to 36 months after SACE. Large cohort-based studies or randomized clinical trials are warranted to confirm these results.

Prediction of hemorrhagic cerebral hyperperfusion syndrome after direct bypass surgery in adult nonhemorrhagic moyamoya disease: combining quantitative parameters on RAPID perfusion CT with clinically related factors.

OBJECTIVE: The aim of this study was to identify predictive factors for hemorrhagic cerebral hyperperfusion syndrome (hCHS) after direct bypass surgery in adult nonhemorrhagic moyamoya disease (non-hMMD) using quantitative parameters on rapid processing of perfusion and diffusion (RAPID) perfusion CT software. METHODS: A total of 277 hemispheres in 223 patients with non-hMMD who underwent combined bypass were retrospectively reviewed. Preoperative volumes of time to maximum (Tmax) > 4 seconds and > 6 seconds were obtained from RAPID analysis of perfusion CT. These quantitative parameters, along with other clinical and angiographic factors, were statistically analyzed to determine the significant predictors for hCHS after bypass surgery. RESULTS: Intra- or postoperative hCHS occurred in 13 hemispheres (4.7%). In 7 hemispheres, subarachnoid hemorrhage occurred intraoperatively, and in 6 hemispheres, intracerebral hemorrhage was detected postoperatively. All hCHS occurred within the 4 days after bypass. Advanced age (OR 1.096, 95% CI 1.039-1.163, p = 0.001) and a large volume of Tmax > 6 seconds (OR 1.011, 95% CI 1.004-1.018, p = 0.002) were statistically significant factors in predicting the risk of hCHS after surgery. The cutoff values of patient age and volume of Tmax > 6 seconds were 43.5 years old (area under the curve [AUC] 0.761) and 80.5 ml (AUC 0.762), respectively. CONCLUSIONS: In adult patients with non-hMMD older than 43.5 years or with a large volume of Tmax > 6 seconds over 80.5 ml, more prudence is required in the decision to undergo bypass surgery and in postoperative management.

Implantation of Acellular Dermal Matrix to Prevent Frontotemporal Depression Following Minipterional Craniotomy for the Surgical Clipping of Unruptured Intracranial Aneurysms.

OBJECTIVE: The objective of the study was to assess the esthetic efficacy of acellular dermal matrix (ADM) implantation to prevent frontotemporal depression (FTD) following minipterional craniotomy (MPT) to clip unruptured intracranial aneurysms. METHODS: We retrospectively compared the incidence of FTD in 100 patients treated without ADM from March to July 2019 and 100 patients treated with ADM from August to December 2019. ADM was implanted in the interfascial layer to cover the temporalis muscle. The specific location and degree of FTD were analyzed by measuring the thickness and area of multiple points (P1-P12) and regions (S1-S3) through brain computed tomography preoperatively and 1 year postoperatively. RESULTS: In the non-ADM group, the thickness at P1, P2, P5, P6, and P9 was reduced and the area of S1 and S2 was smaller after surgery than before surgery (P < 0.05), similar to the incision and suture site of the temporalis muscle. However, in the ADM group, the preoperative and postoperative measurements were not different. FTD recognition was significantly lower in the ADM group (6.0%) than that in the non-ADM group (17.0%) (P = 0.015) and occurred in the retroorbital region through P1, P2, P5, and P6, with the area under the receiver operating characteristic curves of 0.840, 0.766, 0.811, and 0.751, respectively. ADM implantation was the only significant predictive factor for FTD recognition in multivariate logistic regression analysis (odds ratio = 0.30; 95% confidence interval: 0.11-0.79; P = 0.015). CONCLUSIONS: Even MPT cannot completely prevent FTD in the retroorbital region. ADM implantation in MPT can help to improve esthetic satisfaction.

Treatment outcomes of 1-stage clipping of multiple unruptured intracranial aneurysms via keyhole approaches.

OBJECTIVE: Complete exclusion of multiple unruptured intracranial aneurysms (UIAs) in one session of intervention may be ideal. However, such situations are not always feasible in terms of treatment modalities and outcomes. The authors aimed to analyze their experience with 1-stage clipping of multiple UIAs. METHODS: Medical records between March 2013 and December 2018 were retrospectively reviewed, and 111 1-stage keyhole approaches in 110 patients with 261 multiple UIAs were ultimately included in this study. Clinical and radiological outcomes were analyzed, as well as postoperative complications up to 1 month after the surgery and their risk factors. RESULTS: Keyhole approaches included unilateral supraorbital in 87 operations (78.4%), bilateral supraorbital in 12 (10.8%), and others in 12. The mean operative duration was 169.6 minutes (range 80-490 minutes). The highest numbers of aneurysms clipped at once were 2 (73.9%) and 3 (18.9%). Complete exclusion and residual neck of the clipped aneurysms were achieved in 89.3% and 7.3%, respectively. There was no significant difference between pre- and postoperative 1-month neurological states (p = 0.14). The permanent morbidity rate was 1.8% (n = 2), and there were no deaths. Postoperative transient neurological deterioration (TND) with no radiological and electrophysiological abnormalities occurred in 8 operations (7.2%). Hypertension was the only significant risk factor for postoperative TND (adjusted odds ratio 17.03, 95% confidence interval 1.99-2232.24, p = 0.01). CONCLUSIONS: One-stage clipping of multiple UIAs via keyhole approaches showed satisfactory treatment outcomes with a low permanent morbidity. Patients with chronic hypertension had a high risk of postoperative TND.

Benefits and risks of antiplatelet medication in hemodynamically stable adult moyamoya disease.

Revascularization surgery is considered a standard treatment for preventing additional stroke in symptomatic moyamoya disease (MMD). In hemodynamically stable, and asymptomatic or mildly symptomatic patients, however, the treatment strategy is controversial because of the obscure natural course of them. The authors analyzed the benefits and risks of antiplatelet medication in those patients. Medical data were retrospectively reviewed in 439 hemispheres of 243 patients with stable hemodynamic status. Overall, 121 patients (49.8%) with 222 studied hemispheres (50.6%) took antiplatelet medication. Symptomatic cerebral infarction and hemorrhage occurred in 10 (2.3%) and 30 (6.8%) hemispheres, over a mean follow-up of 62.0 ± 43.4 months (range 6-218 months). The use of antiplatelet agents was statistically insignificant in terms of symptomatic infarction, hemorrhage and improvement of ischemic symptoms. In subgroup analyses within the antiplatelet group according to drug potency and duration of medication, a longer duration of antiplatelet medication significantly improved ischemic symptoms (adjusted OR 1.02; 95% CI 1.01-1.03; p = 0.006). Antiplatelet medication failed to prevent symptomatic cerebral infarction or improve ischemic symptoms. However, antiplatelet therapy did not increase the risk of cerebral hemorrhage.

Endovascular Treatment of Intracranial Kissing Aneurysms: Technical Feasibility and Clinical Outcomes.

BACKGROUND: Kissing aneurysms are situated on the same artery but have separate points of origin. Open surgical strategies for access from opposing directions may be technically problematic. Recent advances in protective devices and coiling techniques have compelled the present study, aimed at technical aspects and procedural outcomes of coil embolization in this setting. METHODS: Data prospectively accruing between May 2001 and May 2020 were systematically reviewed, assessing clinical and morphologic outcomes of coil embolization in 36 patients with 72 kissing aneurysms. RESULTS: Lesions most often involved paraclinoid internal carotid artery (n = 22), followed by anterior communicating artery (n = 7). Single-stage coil embolization of both aneurysms took place in nearly all patients (n = 35). Microcatheter tips for selecting paired aneurysms were usually directed opposite to one another (32 of 36, 88.9%), applying protective devices (i.e., balloons or stents) to 1 or both aneurysms in 21 patients (58.3%). Balloons were placed in 9 patients, often when treating first aneurysms and largely for second aneurysms as well (7 of 9, 77.8%). Stents deployed in 14 patients involved first and second aneurysms equally. Two patients required balloon of stent combinations. No procedure-related morbidity or mortality resulted. In follow-up of 68 aneurysms (mean: 40.2 ± 28.1 months) after coiling, 86.8% (59 of 68) showed sustained complete saccular occlusion. CONCLUSIONS: Strategies for endovascular treatment of kissing aneurysms rely heavily on characteristics that the paired aneurysms display. Properly conducted single-stage coil embolization is a safe and effective method of treating such lesions.

Clinical application of 3D virtual and printed models for cerebrovascular diseases.

OBJECTIVE: Three-dimensional (3D) printing techniques are rapidly advancing in the medical industry and in clinical practice. We aimed to evaluate the usefulness of 3D virtual and printed models of 6 representative cerebrovascular diseases using the software we developed. METHODS: Six cases consisted of 4 intracranial aneurysms (IAs) including complex ones with intrasaccular thrombosis, large size and a skull base location; 1 cavernous malformation in the pons; and 1 arteriovenous malformation in the parietal lobe. The 3D modeling process was performed retrospectively in 3 cases and prospectively in 1 IA. Segmentation of raw data and rendering and modification for 3D virtual models were processed mostly automatically. RESULTS: Most intracranial structures were satisfactorily made, including the skull, brain, vessels, thrombus, tentorium and major cranial nerves. Based on 3D modeling, surgical plan was changed in 1 prospective IA case. However, it was still difficult to discriminate small vessels and cranial nerves, to feel a realistic tactile sense and to directly perform presurgical simulations, such as dissection, removal, clipping and microanastomosis. CONCLUSIONS: The 3D modeling was thought to be very helpful in experiencing the operative views from various directions in advance, in selecting an appropriate surgical approach, and in educating physicians and patients. With advancements in radiological resolution, processing techniques and material properties, 3D modeling is expected to simulate real brain tissues more closely.

Surgical strategy for patients with supratentorial spontaneous intracerebral hemorrhage: minimally invasive surgery and conventional surgery.

OBJECTIVE: The role of surgery in spontaneous intracerebral hemorrhage (sICH) is still controversial. We aimed to investigate the effectiveness of minimally invasive surgery (MIS) compared to conventional surgery (CS) for supratentorial sICH. METHODS: The medical data of 70 patients with surgically treated supratentorial sICH were retrospectively reviewed. MIS was performed in 35 patients, and CS was performed in 35 patients. The surgical technique was selected based on the neurological status and radiological findings, such as hematoma volume, neurological status and spot signs on computed tomographic angiography. Treatment outcomes, prognostic factors and the usefulness of the spot sign were analyzed. RESULTS: Clinical states in both groups were statistically similar, preoperatively, and in 1 and 3 months after surgery. Both groups showed significant progressive improvement till 3 months after surgery. Better preoperative neurological status, more hematoma removal and intensive care unit (ICU) stay ≤7 days were the significant prognostic factors for favorable 3-month clinical outcomes (odds ratio [OR] 0.31, 95% confidence interval [CI] 0.10-0.96, p=0.04; OR 1.04, 95% CI 1.01-1.08, p=0.02; OR 26.31, 95% CI 2.46-280.95, p=0.01, respectively). Initial hematoma volume and MIS were significant prognostic factors for a short ICU stay (≤7 days; OR 0.95; 95% CI 0.91-0.99; p=0.01; OR 3.91, 95% CI 1.03-14.82, p=0.045, respectively). No patients in the MIS group experienced hematoma expansion before surgery or postoperative rebleeding. CONCLUSIONS: MIS was not inferior to CS in terms of clinical outcomes. The spot sign seems to be an effective radiological marker for predicting hematoma expansion and determining the surgical technique.

Clinical Factors and Perioperative Strategies Associated with Outcome in Preinjury Antiplatelet and Anticoagulation Therapy for Patients with Traumatic Brain Injuries.

OBJECTIVE: Long-term oral anticoagulation or antiplatelet therapy has been used with increasing frequency in the elderly. These patients are at increased risk of morbidity and mortality from expansion of intracranial hemorrhage. We conducted a single-center retrospective case control study to evaluate risk factors associated with outcomes and to identify the differences in outcome in traumatic brain injury between preinjury anticoagulation use and without anticoagulation. METHODS: A retrospective study of patients who underwent craniotomy or craniectomy for acute traumatic cerebral hemorrhage, between January 2005 and December 2014 was performed. RESULTS: A consecutive series of 50 patients were evaluated. The factors significantly differed between the two groups were initial Prothrombin Time-International Normalized Ratio, initial platelet count, initial Glasgow Coma Scale score, and postoperative intracranial bleeding. Mean Glasgow Outcome Scale (GOS) score were similar between the two groups. In the patient with low-energy trauma only, no significant differences in GOS score, postoperative bleeding and many other factors were observed. The contributing factors to postoperative bleeding was preinjury anticoagulation and its adjusted odds ratio was 12 [adjusted odds ratio (OR), 12.242; p=0.0070]. The contributing factors to low GOS scores, which mean unfavorable neurological outcomes, were age (adjusted OR, 1.073; p=0.039) and Rotterdam scale score for CT scans (adjusted OR, 3.123; p=0.0020). CONCLUSION: Preinjury anticoagulation therapy contributed significantly to the occurrence of postoperative bleeding. However, preinjury anticoagulation therapy in the patients with low-energy trauma did not contribute to the poor clinical outcomes or total hospital stay. Careful attention should be given to older patients and severity of hemorrhage on initial brain CT.

Intracranial Hypertension in a Patient with a Chiari Malformation Accompanied by Hyperthyroidism.

The Chiari malformation is an infrequently detected congenital anomaly characterized by the downward displacement of the cerebellum with a tonsillar herniation below the foramen magnum that may be accompanied by either syringomyelia or hydrocephalus. Surgery, such as foramen magnum decompression, is indicated for a symptomatic Chiari malformation, although an incidental lesion may be followed-up without further treatment. Infrequently, increased intracranial pressure emerges due to hyperthyroidism. A nineteen-year-old girl visited our outpatient clinic presented with a headache, nausea and vomiting. A brain and spinal magnetic resonance image study (MRI) indicated that the patient had a Chiari I malformation without syringomyelia or hydrocephalus. An enlarged thyroid gland was detected on a physical examination, and serum markers indicated Graves' disease. The patient started anti-hyperthyroid medical treatment. Subsequently, the headache disappeared after the medical treatment of hyperthyroidism without surgical intervention for the Chiari malformation. A symptomatic Chiari malformation is indicated for surgery, but a surgeon should investigate other potential causes of the symptoms of the Chiari malformation to avoid unnecessary surgery.

Acute intracranial bleeding and recurrence after bur hole craniostomy for chronic subdural hematoma.

OBJECT: There is inconsistency among the perioperative management strategies currently used for chronic subdural hematoma (cSDH). Moreover, postoperative complications such as acute intracranial bleeding and cSDH recurrence affect clinical outcome of cSDH surgery. This study evaluated the risk factors associated with acute intracranial bleeding and cSDH recurrence and identified an effective perioperative strategy for cSDH patients. METHODS: A retrospective study of patients who underwent bur hole craniostomy for cSDH between 2008 and 2012 was performed. RESULTS: A consecutive series of 303 cSDH patients (234 males and 69 females; mean age 67.17 years) was analyzed. Postoperative acute intracranial bleeding developed in 14 patients (4.57%) within a mean of 3.07 days and recurrence was observed in 37 patients (12.21%) within a mean of 31.69 days (range 10-104 days) after initial bur hole craniostomy. The comorbidities of hematological disease and prior shunt surgery were clinical factors associated with acute bleeding. There was a significant risk of recurrence in patients with diabetes mellitus, but recurrence did not affect the final neurological outcome (p = 0.776). Surgical details, including the number of operative bur holes, saline irrigation of the hematoma cavity, use of a drain, and type of postoperative ambulation, were not significantly associated with outcome. However, a large amount of drainage was associated with postoperative acute bleeding. CONCLUSIONS: Bur hole craniostomy is an effective surgical procedure for initial and recurrent cSDH. Patients with hematological disease or a history of prior shunt surgery are at risk for postoperative acute bleeding; therefore, these patients should be carefully monitored to avoid overdrainage. Surgeons should consider informing patients with diabetes mellitus that this comorbidity is associated with an increased likelihood of recurrence.