Internal maxillary artery bypass for the treatment of complex middle cerebral artery aneurysms.

OBJECTIVEThe rapid innovation of the endovascular armamentarium results in a decreased number of indications for a classic surgical approach. However, a middle cerebral artery (MCA) aneurysm remains the best example of one for which results have favored microsurgery over endovascular intervention. In this study, the authors aimed to evaluate the experience and efficacy regarding surgical outcomes after applying internal maxillary artery (IMA) bypass for complex MCA aneurysms (CMCAAs).METHODSAll IMA bypasses performed between January 2010 and July 2018 in a single-center, single-surgeon practice were screened.RESULTSIn total, 12 patients (9 males, 3 females) with CMCAAs managed by high-flow IMA bypass were identified. The mean size of CMCAAs was 23.7 mm (range 10-37 mm), and the patients had a mean age of 31.7 years (range 14-56 years). The aneurysms were proximally occluded in 8 cases, completely trapped in 3 cases, and completely resected in 1 case. The radial artery was used as the graft vessel in all cases. At discharge, the graft patency rate was 83.3% (n = 10), and all aneurysms were completely eliminated (83.3%, n = 10) or greatly diminished (16.7%, n = 2) from the circulation. Postoperative ischemia was detected in 2 patients as a result of graft occlusion, and 1 patient presenting with subarachnoid hemorrhage achieved improved modified Rankin Scale scores compared to the preoperative status but retained some neurological deficits. Therefore, neurological assessment at discharge showed that 9 of the 12 patients experienced unremarkable outcomes. The mean interval time from bypass to angiographic and clinical follow-up was 28.7 months (range 2-74 months) and 53.1 months (range 19-82 months), respectively. Although 2 grafts remained occluded, all aneurysms were isolated from the circulation, and no patient had an unfavorable outcome.CONCLUSIONSThe satisfactory result in the present study demonstrated that IMA bypass is a promising method for the treatment of CMCAAs and should be maintained in the neurosurgical armamentarium. However, cases with intraoperative radical resection or inappropriate bypass recipient selection such as aneurysmal wall should be meticulously chosen with respect to the subtype of MCA aneurysm.

Preoperative embolization of skull base meningiomas: current indications, techniques, and pearls for complication avoidance.

Skull base meningiomas are technically challenging tumors to treat because of their deep vascular supply that can preclude early devascularization during resection. Preoperative embolization of these arterial feeders is thought to decrease blood loss and facilitate resection; however, given the complex and varied anatomy of these skull base lesions, preoperative embolization is not without risk. It is essential for both endovascular and skull base neurosurgeons to understand these risks in light of the potential benefits. The authors review the vascular anatomy of skull base meningiomas, indications for preoperative devascularization, endovascular techniques, and published results regarding embolization of these lesions.

Development of a recalcitrant, large clot burden, bifurcation occlusion model for mechanical thrombectomy.

OBJECTIVE Stroke is a major cause of disability and death in adults. Several large randomized clinical trials have shown the significant benefit of mechanical thrombectomy with modern stent retrievers in the treatment of large-vessel occlusions. However, large clots located at bifurcations remain challenging to treat. An in vivo model of these recalcitrant clots needs to be developed to test future generations of devices. METHODS Autologous blood was drawn from anesthetized swine via a femoral sheath. Blood was then mixed with thrombin, calcium chloride, and saline, and injected into silicone tubing to form cylindrical clots in the standard fashion. Matured clots were then delivered in an unfragmented fashion directly into the distal extracranial vasculature, at branch points where vessel sizes mimic the human middle cerebral artery, by using Penumbra aspiration tubing and the Penumbra ACE68 reperfusion catheter. RESULTS A total of 5 adult swine were used to develop the model. The techniques evolved during experiments in the first 3 animals, and the last 2 were used to establish the final model. In these 2 swine, a total of 8 autologous clots, 15-20 mm, were injected directly into 8 distal extracranial vessels at branch points to mimic a bifurcation occlusion in a human. All clots were delivered directly at a distal bifurcation or trifurcation in an unfragmented fashion to cause an occlusion. Ten revascularization attempts were made, and none of the branch-point occlusions were fully revascularized on the first attempt. CONCLUSIONS Using novel large-bore distal access catheters, large unfragmented clots can be delivered into distal extracranial vessels in a swine occlusion model. The model mimics the clinical situation of a recalcitrant bifurcation occlusion and will be valuable in the study of next-generation stroke devices and in training settings.

Bypass surgery to treat symptomatic fusiform dilation of the internal carotid artery following craniopharyngioma resection: report of 2 cases.

Fusiform dilation of the internal carotid artery (FDICA) is an infrequent vascular complication following resection of suprasellar lesions in the pediatric population, and its course appears to be benign without apparent clinical symptoms. However, data correlating symptomatic FDICA with bypass surgery are scarce. The authors here report 2 symptomatic cases that were treated using internal maxillary artery bypass more than 5 years after total removal of a craniopharyngioma at an outside institution. Both cases of FDICA were resected to relieve the mass effect and to expose the craniopharyngioma. The postoperative course was uneventful, and radiological imaging revealed graft conduit patency. To the authors' knowledge, this is the first reported use of extracranial to intracranial bypass to treat FDICA following removal of a suprasellar lesion. Their findings suggest that bypass surgery is a useful therapeutic approach for symptomatic cases of FDICA and total removal of recurrent craniopharyngioma. Moreover, the indications for surgical intervention and treatment modalities are discussed in the context of previous relevant cases.

Transarterial embolization through the infraorbital artery of the ethmoidal dural arteriovenous fistula causing recurrent epistaxis: illustrative case.

BACKGROUND: This report describes an ethmoidal dural arteriovenous fistula (DAVF) presenting with the unusual symptom of recurrent epistaxis and successfully treated with selective transarterial embolization through the infraorbital artery (IOA), which is the first time this route was used to the best of the authors' knowledge, and reviews the literature focusing on the anatomical consideration of ethmoidal DAVFs causing epistaxis and its treatment approaches. OBSERVATIONS: A 70-year-old man experienced recurrent intractable epistaxis that bled like a faucet turned on. Cerebral angiography revealed an ethmoidal DAVF supplied by the left anterior ethmoidal artery, both sphenopalatine arteries, both IOAs, and the right angular artery, which drained directly into the frontal cortical veins with a tortuous arterialized ectasia. Microaneurysms around the fistulous location where multiple feeding arteries converge were demonstrated and considered the likely source of the epistaxis. The fistula was completely occluded using transarterial Onyx embolization through the IOA, a branch of the internal maxillary artery. No further epistaxis appeared. LESSONS: Although extremely rare, ethmoidal DAVFs should be included in the differential diagnosis of recurrent epistaxis. Ethmoidal DAVFs with bleeding sources in the ethmoid sinus and nasal cavity may cause epistaxis. It is important to properly diagnose and treat ethmoidal DAVFs presenting with epistaxis on the basis of a comprehensive anatomical understanding of extensive extracranial-extracranial and extracranial-intracranial anastomoses.

Endoscopic endonasal transpterygoid transnasopharyngeal management of petroclival chondrosarcomas without medial extension.

Chondrosarcomas of the skull base are malignant tumors for which surgery is the primary therapeutic option. Gross-total resection has been demonstrated to improve survival in patients with these tumors. Chondrosarcomas arising from the petroclival synchondrosis harbor particularly unique anatomical considerations that have long been a barrier to achieving such a resection. Endoscopic endonasal transpterygoid approaches have been recently used to gain improved access to such lesions; however, these approaches have classically relied on a medial to lateral transclival trajectory, which provides limited exposure for complete resection of lateral disease. In this paper the authors describe an endoscopic endonasal transpterygoid transnasopharyngeal approach that provides comprehensive access to the petroclival region through dissection of the eustachian tube with resection of the cartilaginous torus tubarius. Of note, the authors have previously demonstrated the superior outcomes and validity of this approach relative to other cranial base techniques for petroclival chondrosarcomas. Surgical outcomes in 5 cases of chondrosarcoma without medial extension are detailed. Gross-total resection was achieved in 4 of 5 patients. Postoperative complications included transient palatal numbness in all patients and eustachian tube dysfunction due to the approach. With tympanostomy tube placement, no patient had persistent hearing loss. Overall, this approach appears to be a safe and effective technique for resection of petroclival chondrosarcomas.

The intranasal endoscopic removal of schwannoma of the pterygopalatine and infratemporal fossae via the prelacrimal recess approach.

OBJECTIVE: This study was undertaken to analyze the results of a novel surgical method-the endoscopic prelacrimal recess approach (PLRA)-in patients with tumors involving the pterygopalatine fossa (PPF) and infratemporal fossa (ITF). The surgical technique and indications for this approach are also discussed. METHODS: The authors analyzed data from 7 cases involving patients who underwent resection of PPF and ITF tumors by means of the endoscopic PLRA from 2004 to 2013. Preoperative and postoperative imaging studies were available in all cases and were reviewed. The surgical specimens were all confirmed to be schwannomas. RESULTS: All tumors were completely resected via endoscopic PLRA. There were no recurrences noted over a 28-month follow-up period. In 4 cases, the patients experienced postoperative facial numbness during the first two weeks after surgery, which gradually lessened thereafter. One patient continued to have mild facial numbness at most recent follow-up. The numbness had fully resolved in the other 3 cases. CONCLUSIONS: The intranasal endoscopic removal of schwannoma from PPF and ITF via PLRA can spare the whole lateral nasal wall, resulting in a reduction in morbidity. This is a novel minimally invasive surgical method for PPF and ITF tumors.