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.

The History and Evolution of Internal Maxillary Artery Bypass.

Internal maxillary artery (IMA) bypass has gained momentum in the last 5 years for the treatment of complex cerebrovascular disorders and skull base tumors. However, some issues regarding this treatment modality have been proposed. As one of the most experienced neurosurgical teams to perform internal maxillary artery bypass in the world (>100 clinical cases), we reviewed the literature in aspects of basic anatomy of maxillary artery with its variations to the lateral pterygoid muscle, initial anastomosis modalities, and subsequent exposure techniques in cadaver studies, preoperative arterial evaluation methods, optimal interposed graft selections, and surgical outcome in the management of complex aneurysms, skull base tumors, and steno-occlusive disorders.

Internal Maxillary Artery Bypass with Radial Artery Graft Treatment of Giant Intracranial Aneurysms.

BACKGROUND: Giant intracranial aneurysms (GIAs) can be approached via microsurgical and endovascular techniques. Use of flow diversion devices has yielded favorable outcomes, and indications for cerebral revascularization have dramatically decreased. OBJECTIVE: To evaluate the safety and validity of using internal maxillary artery (IMA) bypass with an interposed graft to treat GIAs. METHODS: During a 6-year period, high-flow IMA bypass procedures were performed in 32 patients with GIAs at our institute. Intraoperative Doppler sonography, indocyanine green, and postoperative angiography were used to assess the patency of the graft conduit and the stability of the aneurysm. Neurologic function was assessed with the modified Rankin Scale. RESULTS: The mean GIA size was 33.7 mm (range, 25.3-64 mm), and all showed a nonsaccular morphology, except for 1 patient who underwent a first attempt at surgical clipping of a saccular aneurysm. Complete occlusion (65.6%, n = 21) or great diminishment (28.1%, n = 9) of the GIA was shown in 30 patients and the graft patency rate was 90.6% (n = 29). No deaths resulting from bypass surgery occurred. Functionally favorable outcomes (modified Rankin Scale score of 0-2) were recorded in 65.6% of patients at discharge, and the rate increased to 71.9% at the most recent follow-up (mean, 40.6 months). Surgical-related complications involving hydrocephalus and ischemic and hemorrhagic episodes were encountered in 5 patients, but 4 had complete regression of their neurologic symptoms. CONCLUSIONS: Considering the grave natural history and treatment complexity of these lesions, this study showed satisfactory results in the treatment of GIAs with IMA bypass.

Internal Maxillary Bypass for Complex Pediatric Aneurysms.

BACKGROUND: Complex pediatric aneurysms (PAs) are an unusual clinicopathologic entity. Data regarding the use of a bypass procedure to treat complex PAs are limited. METHODS: Internal maxillary artery-to-middle cerebral artery bypass with radial artery graft was used to isolate PAs. Bypass patency and aneurysm stability were evaluated using intraoperative Doppler ultrasound, indocyanine green videoangiography, and postoperative angiography. Modified Rankin Scale was used to assess neurologic function. RESULTS: Over a 5-year period, 7 pediatric patients (≤18 years old) were included in our analysis. Mean age of patients was 14.4 years (range, 12-18 years), and mean size of PAs was 23.6 mm (range, 9-37 mm). All cases manifested with complex characteristics. Proximal artery occlusion was performed in 3 cases, complete excision following aneurysmal distal internal maxillary artery bypass was performed in 2 cases, and combined proximal artery occlusion and aneurysm excision was performed in the 2 remaining cases. Mean intraoperative blood flow was 61.6 mL/minute (range, 40.0-90.8 mL/minute). Graft patency rate was 100% during postoperative recovery and at the last follow-up examination (mean, 20 months; range, 7-45 months). All patients had excellent outcomes except for 1 patient who died of multiple-organ failure. CONCLUSIONS: Internal maxillary artery bypass is an essential technique for treatment of selected cases of complex PAs.

Outcome of Radical Surgical Resection for Craniopharyngioma with Hypothalamic Preservation: A Single-Center Retrospective Study of 1054 Patients.

OBJECTIVE: A retrospective review of the surgical outcome for patients with craniopharyngioma (CP) treated in a single neurosurgical center with surgical resection using visualization to ensure hypothalamic preservation. METHODS: The study included 1054 patients. Before 2003, a pterional cranial approach was preferred for 78% of patients; after 2004, the unifrontal basal interhemispheric approach was performed in 79.1% of patients. RESULTS: Complete tumor resection was achieved in 89.6% of patients; vision improved in 47.1% of patients who had preoperative vision impairment. However, diabetes insipidus worsened in 70.4% of patients and new-onset diabetes insipidus occurred in 29.7% of the remaining patients. Pituitary stalk preservation occurred in 48.9% of cases. There were 89.6% of patients with total tumor removal; 13.3% of patients showed tumor recurrence within an average of 2.8 years. Of 69 follow-up patients with a subtotal or partial resection, 94.2% showed tumor recurrence within an average of 4.3 months. Of the total patients, 82.3% fully recovered. CONCLUSIONS: This study has shown that radical surgical resection of CP using microsurgical excision can be effective with a good patient outcome without more limitations on each individual tumor of distinct features despite the impact of recent endoscopic techniques on CP surgery. The surgical approach depends on a direct and wider visualization of CP located in the midline with preserving hypothalamic structures by identifying some hypothalamic landmark structures. After surgery, most patients can resume their normal activities even after aggressive tumor removal, although patients require postoperative hormonal replacement.