Minipterional Approach for Middle Fossa Skull Base Lesions: Technical Note.

Surgical access to the middle fossa can be technically challenging. As neurosurgery evolves to minimally invasive approaches, the objective of this study is to demonstrate the extension of the Minipterional approach to access the middle fossa. We present a new surgical approach to the middle fossa for the treatment of secondary trigeminal neuralgia. Three cases are reported to illustrate the following techniques: a patient with petrotentorial meningioma and trigeminal neuralgia, a patient with an arachnoid cyst compressing the fifth nerve, and a patient with a middle cerebral artery aneurysm and a long history of TN (trigeminal neuralgia) refractory to medical and surgical treatments. All three experienced full symptom controls with no permanent neurological deficits. Therefore, the Minipterional technique might represent a feasible, effective, and safe option to treat refractory secondary TN. It also allows approaching these lesions when the posterior fossa approach is compromised by anatomical distortion and enables the simultaneous treatment of secondary trigeminal neuralgia and other lesions, such as aneurysms and meningiomas.

Microsurgical Anatomy of the Anterior Circulation of the Brain Adjusted to the Neurosurgeon's Daily Practice.

The study of cerebrovascular anatomy can be difficult and may take time due to its intrinsic complexity. However, it can also be difficult for the following reasons: the excessive description of neuroanatomy making articles hard to read, the unclear clinical application of what is written, the use of simplified or intricate schematic drawings that are not always appropriate for effective teaching, the poor quality of neuroanatomy dissections and the use of unusual views of figures that are not strictly related to the most frequent neuroimages to be interpreted in daily practice. Because of this, we designed an article that incorporates original and accurate anatomical dissections in an attempt to improve its comprehensibility. Five formalin-fixed adult cadaveric heads, whose vessels were injected with a colored silicone mixture (red for arteries and blue for veins), were dissected and examined under a microscope with magnifications from 3× to 40×. Special emphasis has been placed on correlating topographic anatomy with routine neuroimaging studies from computed tomographic angiography (CTA) and digital subtraction angiography (DSA). The essential surgical anatomy in a neurosurgeon's daily practice is also described. The cadaveric dissections included in this study contribute to the understanding of the cerebrovascular anatomy necessary for the neurosurgeon's daily practice.

Management of Giant Thrombosed MCA Aneurysm: Double STA-MCA Revascularization.

Giant middle cerebral artery (MCA) aneurysms are rare complex cerebrovascular lesions to treat.1 The management of those aneurysms may be very challenging, despite the introduction of refined microsurgical techniques and the rapid progress in endovascular methods, which often require bypass surgery as part of the strategy.2-4 This approach is particularly relevant to giant, dolichoectatic, and thrombotic aneurysms.5,6 This video shows the surgical strategy and stepwise depiction of the surgical treatment of a complex giant thrombosed aneurysm using a double-barrel superficial temporal artery (STA) to MCA bypass (Video 1). Informed written consent was obtained from the patient and his family. The patient was a 50-year-old man, previously healthy, who presented with headache, memory difficulty, and left-sided involuntary movements for 2 months. Computed tomography scan showed a giant round calcified and heterogeneous lesion compatible with a thrombosed MCA aneurysm. Brain magnetic resonance imaging showed the same lesion with a flow void signal inside in a serpentine fashion and a complete hemosiderin halo. Conventional angiography showed the false lumen and the filling of the distal MCA branches with a certain degree of arterial delay. The lesion was located between M1 and M3 segments of MCA. Extracranial-intracranial STA-MCA bypass was performed. Then we opened the aneurysm sac for decompression and observed the lenticulostriate artery branches arising away from the aneurysm sac. The complete clipping and patency of the anastomosis was validated during surgery by indocyanine green angiography. Postoperative cerebral computed tomography angiography revealed good patency from the STA to the MCA. The patient was neurologically intact without complains.

Microsurgical clipping of multiple cerebral aneurysms in the acute phase of aneurysmal subarachnoid hemorrhage through a minipterional approach: The Chilean experience.

OBJECTIVE: The minipterional craniotomy (MPTc) has been widely accepted as a minimally invasive alternative to the pterional approach for the treatment of certain small non-ruptured anterior circulation aneurysms. The aim of this study was to determine the effectiveness and safety of the MPTc in the context of a complex and potentially harmful scenario: acute onset of subarachnoid hemorrhage (SAH) in patients harboring multiple intracranial aneurysms (MIA). METHODS: Patients harboring MIA clipped through a unilateral MPTc were selected from four retrospective databases of four high-volume neurosurgical centers. Patients with a Hunt & Hess score 4 or 5 were not considered candidates for clipping through a MPTc. Medical records and radiological images were retrospectively reviewed. Epidemiological, clinical and radiological data, as well as short-term outcome (modified Rankin scale at 6 month-follow-up) were analyzed. RESULTS: 16 patients harboring 33 aneurysms (16 ruptured, 17 non ruptured) met the inclusion criteria. Each aneurysm size was 5.7 ± 2.1 mm (range 3-11). 12 out of 33 aneurysms were located in the middle cerebral artery (MCA). Anterior communicating (ACom) and MCA aneurysms were the aneurysm locations most commonly ruptured (5 each, 62 %). Complete occlusion was achieved in 32 aneurysms (97 %) and near-complete occlusion in 1 (3%). 13 patients (93 %) were independent at 6 month-follow-up. Mortality rate was 0%. Complications included 1 cerebrospinal-fluid leakage. CONCLUSION: When indicated (Hunt Hess < 4), performing a MPTc is safe and effective in aSAH cases with multiple aneurysms.

Extradural minipterional approach: Evolving indications of the minipterional craniotomy.

BACKGROUND: In this paper, we report a clinical series of skull base lesions operated on trough the MiniPT, extending its application to skull base lesions, either using the classical minipterional or a variant, we call extradural minipterional approach (MiniPTEx). METHODS: We describe our surgical technique of operating on complex skull base lesions using a minipterional extradural approach. Anterior clinoidectomy, middle fossa peeling, transcavernous, and Kawase approaches were performed as needed. In total, we carried out 24 surgeries: three skull base tumors, 1 Moyamoya case, and 20 giant/complex intracranial aneurysms. All the patients present good neurological result (mRs < 3). Only two patients had paralysis of any cranial nerve and only one patient had a mild hemiparesis. RESULTS: This surgery series there are 24 cases, 10 patients were treated with exclusive MiniPT. MiniPT extradural approach was made in 14 patients. Twelve were treated using pure MiniPTEx approach, 1 patient using transcavernous approach, and in 1 patient, the anterior clinoid was resected with the combination of a MiniPT, a medium fossa peeling, and the Kawase anterior petrosectomy for skull base surgery. CONCLUSION: We further advance the indications of the MiniPT by extending it to operate on the cranial base tumors or complex vascular lesions without additional morbidity. MiniPT approach may be safely associated with skull base techniques, including anterior and posterior clinoidectomies, peeling of the middle fossa, transcavernous approach, and anterior petrosectomy. The versatility of the MiniPT craniotomy and the feasibility of performing skull base surgery through the MiniPT technique have been demonstrated in this paper.

The extradural minipterional pretemporal approach for the treatment of spheno-petro-clival meningiomas.

BACKGROUND: Cavernous sinus and petroclival region is an anatomically complex region in close relationship with important neurovascular structures. As such, the surgical treatment of spheno-petro-clival (SPC) meningiomas represents an operative challenge, in which several routes and its combinations might be used. METHODS: We describe in detail the surgical technique of the extradural minipterional pretemporal approach (eMPT-P) to the SPC region and highlight the main anatomical key elements involved in this approach as well as the technical aspects for avoiding surgical complications. CONCLUSION: The eMPT-P is a versatile approach that uses the extradural route, and thereby reduces brain retraction, while provides a good angle of exposure of the SPC region.

Angiographic Findings in Refractory Delayed Cerebral Ischemia

Background Delayed cerebral ischemia (DCI) follows a refractory course in a subgroup of patients with aneurysmal subarachnoid hemorrhage (SAH), leading to diffuse ischemic injury. The role of angiographic vasospasm (AV) is unknown. Our goal is to study the angiographic alterations and the clinical profile of refractory DCI patients. Methods Retrospective study of patients with SAH who presented with DCI treated with medical and endovascular therapy, with a refractory evolution, defined asmultiple ischemic infarction and brain death. Results Out of a cohort of 336 patients, 7 (2%) developed refractory DCI. The median age of the patients was 48 (38­60) years old. Five patients had ruptured anterior communicating artery (ACoA) aneurysms. Four patients were treated with coil embolization, and three with microsurgical clipping. Angiographic vasospasm was classified as severe in 5 cases. Compromise of bilateral circulation was detected in six patients. Distal circulation vasospasm occurred in five cases. Slow circulatory transit times were observed in three patients. Conclusion Angiographic findings such as bilateral circulatory compromise and distal vasospasm were frequent alterations. Further studies are required to establish the association of these findings with the clinical outcomes.

Technical Description of Minimally Invasive Extradural Anterior Clinoidectomy and Optic Nerve Decompression. Study of Feasibility and Proof of Concept.

BACKGROUND: Several diseases that involve the optic canal or its contained structures may cause visual impairment. Several techniques have been developed to decompress the optic nerve. OBJECTIVE: To describe minimally invasive extradural anterior clinoidectomy (MiniEx) for optic nerve decompression, detail its surgical anatomy, present clinical cases, and established a proof of concept. METHODS: Anatomic dissections were performed in cadaver heads to show the surgical anatomy and to show stepwise the MiniEx approach. In addition, these surgical concepts were applied to decompress the optic nerve in 6 clinical cases. RESULTS: The MiniEx approach allowed the extradural anterior clinoidectomy and a nearly 270° optic nerve decompression using the no-drill technique. In the MiniEx approach, the skin incision, dissection of the temporal muscle, and craniotomy were smaller and provided the same extent of exposure of the optic nerve, anterior clinoid process, and superior orbital fissure as that usually provided by standard techniques. All patients who underwent operation with this technique had improved visual status. CONCLUSIONS: The MiniEx approach is an excellent alternative to traditional approaches for extradural anterior clinoidectomy and optic nerve decompression. It may be used as a part of more complex surgery or as a single surgical procedure.

The "Brain Stress Timing" phenomenon and other misinterpretations of randomized clinical trial on aneurysmal subarachnoid hemorrhage.

Clipping and coiling are currently the two alternatives in treatment of ruptured cerebral aneurysms. In spite of some meritorious analysis, further discussion is helpful to understand the actual state of art. Retreatment and rebleeding rates clearly favors clipping, although short-term functional outcome seems to be beneficial for clipping, while this different is not such if we perform the comparison at a longer follow up. Long-term follow ups and cost analysis are mandatory to have a clear view of the current picture in treatment of subarachnoid hemorrhage. Treatment strategy should be made by a multi-disciplinary team in accredited centers with proficient experience in both techniques.

Long-chain omega-3 fatty acids in aneurysmal subarachnoid hemorrhage: A randomized pilot trial of pharmaconutrition.

BACKGROUND: Functional recovery after aneurysmal subarachnoid hemorrhage (SAH) remains a significant problem. We tested a novel therapeutic approach with long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs) to assess the safety and feasibility of an effectiveness trial. METHODS: We conducted a multicentre, parallel, randomized, open-label pilot trial. Patients admitted within 72 hours after SAH with modified Fisher scale scores of 3 or 4 who were selected for scheduled aneurysm clipping were allocated to receive either n-3 PUFA treatment (parenteral perioperative: 5 days; oral: 8 weeks) plus usual care or usual care alone. Exploratory outcome measures included major postoperative intracranial bleeding complications (PIBCs), cerebral infarction caused by delayed cerebral ischemia, shunt-dependent hydrocephalus, and consent rate. The computed tomography evaluator was blinded to the group assignment. RESULTS: Forty-one patients were randomized, but one patient had to be excluded after allocation. Twenty patients remained for intention to treat analysis in each trial arm. No PIBs (95% confidence interval [CI]: 0.00 to 0.16) or other unexpected harm were observed in the intervention group (IG). No patient suspended the intervention due to side effects. There was a trend towards improvements in all benefit-related outcomes in the IG. The overall consent rate was 0.91 (95% CI: 0.78 to 0.96), and there was no consent withdrawal. CONCLUSIONS: Although the balance between the benefit and harm of the intervention appears highly favourable, further testing on SAH patients is required. We recommend proceeding with amendments in a dose-finding trial to determine the optimal duration of parenteral treatment.

Multiple myxomatous aneurysms with bypass and clipping in a 37-year-old man.

BACKGROUND: Cardiac myxoma is the most common cardiac tumor. Neurologic complications are seen in 20%-35%, most frequently embolic ischemic stroke, and rarely secondary to intracranial aneurysms. The mechanism of aneurysm formation in these patients is speculative. METHODS: We report, herein, a 37-year-old male with a cardiac myxoma who experienced repeated ischemic stroke and intracerebral hematoma despite resection of heart tumor, secondary to multiple cerebral aneurysm. RESULTS: We offered him surgery with a bypass and clipping, because growing of aneurysm was not suitable for endovascular treatment. CONCLUSION: Bypass and clipping are possible options in this type of disease. Aneurysm biopsy supports mycotic theory of aneurysm formation.

Use of superior thyroid artery as a donor vessel in extracranial-intracranial revascularization procedures: a novel technique.

Objective To describe the use of the superior thyroid artery as a donor vessel in extracranial-intracranial (EC-IC) revascularization when a "low-flow" bypass is required and the superficial temporal artery is not available. Design Case report. Setting University hospital. Participants Four cases. Main Outcome Measures Postoperative course after EC-IC bypass surgery. Results In case 1, the parent vessel was occluded postoperatively. The radial bypass was sufficient to replace the internal carotid artery (ICA) flow, and a prophylactic was turned into a definitive bypass. In case 2, the superior thyroid artery was used because the radial artery was not long enough to reach the external carotid artery. The recipient vessel was modified from the middle cerebral artery to the ophthalmic segment of the ICA. In case 3, the graft was occluded after surgery because of carotid artery reconstruction. In case 4, after surgery/radiotherapy for meningioma, the patient developed wound dehiscence and was reoperated for bypass occlusion. The graft was weak and bled intraoperatively, without infarction. The three first patients are intact, and the fourth remains disabled (Glasgow Outcome Scale: 3; Rankin Scale: 5). Conclusion The superior thyroid artery was adequate for proximal anastomosis in EC-IC procedures in the situations described.

Fluid structural analysis of human cerebral aneurysm using their own wall mechanical properties.

Computational Structural Dynamics (CSD) simulations, Computational Fluid Dynamics (CFD) simulation, and Fluid Structure Interaction (FSI) simulations were carried out in an anatomically realistic model of a saccular cerebral aneurysm with the objective of quantifying the effects of type of simulation on principal fluid and solid mechanics results. Eight CSD simulations, one CFD simulation, and four FSI simulations were made. The results allowed the study of the influence of the type of material elements in the solid, the aneurism's wall thickness, and the type of simulation on the modeling of a human cerebral aneurysm. The simulations use their own wall mechanical properties of the aneurysm. The more complex simulation was the FSI simulation completely coupled with hyperelastic Mooney-Rivlin material, normal internal pressure, and normal variable thickness. The FSI simulation coupled in one direction using hyperelastic Mooney-Rivlin material, normal internal pressure, and normal variable thickness is the one that presents the most similar results with respect to the more complex FSI simulation, requiring one-fourth of the calculation time.

The anterior ventriculo-cisternostomy: the pioneers' work revisited.

BACKGROUND: There is no satisfactory medical treatment for hydrocephalus and most often surgical treatment is necessary, including shunting or endoscopic third ventriculostomy (ETV), both with their well-known advantages and drawbacks. The objective of this study is to describe a contemporary series of anterior ventriculocisternostomy. PATIENTS: Twenty-two patients with hydrocephalus treated at two institutions between 2005 and 2009 were presented. The authors employed a technique called anterior ventriculocisternostomy to treat selected cases. This technique includes supraciliary incision, small craniotomy, and fenestration of the lamina terminalis and Liliquist membrane. Hydrocephalus was secondary to hemorrhage from arteriovenous malformation (3 cases), spontaneous subarachnoid hemorrhage (2 cases), posterior fossa tumors (4 cases), head injury (1 case), basilar aneurysm (1 case), and posterior fossa hemorrhage (1 case). Eight patients had a normal-pressure hydrocephalus syndrome and one patient a slit ventricle syndrome. Aqueduct obstruction was noticed in one patient. Patients were followed up for 20.2 months (range: 10 to 46 months). RESULTS: No hemorrhagic complications or parenchymal injury were observed. One cerebrospinal fluid leakage occurred. No infection, mortality, and neurological morbidity were reported. Improvements were noticed in 18 cases. Eighty-two percent of the patients remained independent of shunt. CONCLUSION: Anterior ventriculocisternostomy integrates old views of open ventriculocisternostomy with contemporary concepts of minimally invasive neurosurgery. It provides the most straightforward anatomical and physiological alternative to treat many types of hydrocephalus with no significant morbidity. Compared with conventional procedures, it has several advantages. This procedure is an important option to manage hydrocephalus and constitutes a safe, effective, and relatively inexpensive alternative to ETV and shunts.

Simplified azygos anterior cerebral bypass: y-shaped superficial temporal artery interposition graft from A2 with double reimplantation of pericallosal arteries: technical case report.

BACKGROUND AND IMPORTANCE: Trapping with distal revascularization is a therapeutic option for giant aneurysms that cannot be clipped or coiled. In skull base lesions such as meningiomas, arterial encasement is often present, requiring, in some cases, revascularization procedures: extracranial-to-intracranial bypass and more recently intracranial-to-intracranial techniques. These techniques are used only in exceptional cases of tumors in other localizations. CLINICAL PRESENTATION: We report a case of a recurrent malignant frontal falx meningioma with encasement of both pericallosal arteries (PcaAs). During resection of the lesion, the left PcaA was sectioned and the right PcaA was occluded for manipulation and coagulation of the tumor. The occlusion was diagnosed with indocyanine green videoangiography. A Y-shaped superficial temporal artery graft was obtained in the right side, and the anterior cerebral artery circulation was reconstructed using an intracranial-to-intracranial bypass in the following fashion: right A2 to superficial temporal artery Y-shaped graft for both PcaAs. The patient's postoperative period was uneventful with no deficit, and the computed tomography angiography showed the preservation of both PcaAs. CONCLUSION: To the best of our knowledge, this microsurgical reconstruction of the PcaAs has not been performed before in a meningioma or a complex aneurysm case. We think the use of a superficial temporal artery as an in situ graft is more straightforward compared with other interposition grafts such as the radial artery graft or saphenous vein graft. The use of intracranial-to-intracranial techniques is the proper evolution of the use of classic extracranial-to-intracranial cerebral revascularization techniques.

Vertebral artery reconstruction using microanastomosis and intraoperative neuromonitoring: a case report from Santiago, Chile.

Jorge Mura, M.D. performed the microsurgery presented in this report on August 22, 2006 at the Institute of Neurosurgery Asenjo in Santiago, Chile. A highly vascularized tumor was present in the patient's only functional vertebral artery. Intraoperative neuromonitoring was conducted throughout the procedure. Following resection of the tumor and completion of the vertebral artery microanastomosis, somatosensory evoked potentials were improved from baseline potentials. Motor function was stable throughout the procedure. A post-operative computerized tomography (CT) angiogram showed that the reconstructed artery was normal and three times the size of the right vertebral artery. The patient had no post operative deficits. The preliminary result of the biopsy was an angiofibroma.