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The goal of this survey is to investigate the indications for preoperative digital subtraction angiography (DSA) before clipping of ruptured and unruptured intracranial aneurysms in an international panel of neurovascular specialists.An anonymous survey of 23 multiple-choice questions relating to indications for DSA before clipping of an intracranial aneurysm was distributed to the international panel of attendees of the European-Japanese Cerebrovascular Congress (EJCVC), which took place in Milan, Italy on 7-9 June 2018. The survey was collected during the same conference. Descriptive statistics were used to analyze the data.A total of 93 surveys were distributed, and 67 (72%) completed surveys were returned by responders from 13 different countries. Eighty-five percent of all responders were neurosurgeons. For unruptured and ruptured middle cerebral artery (MCA) aneurysms without life-threatening hematoma, approximately 60% of responders perform surgery without preoperative DSA. For aneurysms in other locations than MCA, microsurgery is done without preoperative DSA in 68% of unruptured and in 73% of ruptured cases. In cases of ruptured MCA or ruptured non-MCA aneurysms with life-threatening hematoma, surgery is performed without DSA in 97% and 96% of patients, respectively. Factors which lead to preoperative DSA being performed were: aneurysmal shape (fusiform, dissecting), etiology (infectious), size (25 mm), possible presence of perforators or efferent vessels arising from the aneurysm, intra-aneurysmal thrombus, previous treatment, location (posterior circulation and paraclinoid aneurysm) and flow-replacement bypass contemplated for final aneurysm treatment. These are all factors that qualify an aneurysm as a complex aneurysm.There is still a high variability in the surgeons' preoperative workup regarding the indication for DSA before clipping of ruptured and unruptured intracranial aneurysms, except for ruptured aneurysms with life-threatening hematoma. There is a general consensus among cerebrovascular specialists that any angioanatomical feature indicating a complex aneurysm should lead to a more detailed workup including preoperative DSA.

In Japan, hybrid neurosurgeons who perform both open surgical clipping as well as endovascular embolization for the treatment of intracranial aneurysms are common. Although many Japanese neurosurgeons can perform surgical clipping of middle cerebral artery aneurysms or internal carotid artery-posterior communicating artery aneurysms and coil embolization of cerebral aneurysms using simple techniques-only a limited number of neurosurgeons are able to perform surgical clipping and endovascular procedures for anterior communicating artery aneurysms, paraclinoid, or posterior circulation aneurysms using both treatment modalities equally and safely.The senior author's personal experience of more than 500 cases each of surgical clipping and endovascular embolization over the past 25 years included 110 cases of basilar tip aneurysms and 104 cases of paraclinoid internal carotid artery (ICA) aneurysms.The safety and efficacy of both treatments appears to be the same, while the durability of surgical clipping is superior to that of endovascular embolization. Among the 110 basilar tip aneurysms, 18 patients were treated by surgical clipping and 94 were treated by endovascular embolization. The initial results of endovascular therapy seemed to be better than those of surgical clipping, although the rate of retreatment was higher. Among the 104 cases of paraclinoid ICA aneurysm, 23 patients were treated by surgical clipping and 81 were treated by endovascular embolization. The results of both treatments seemed to be same, while surgical clipping had apparently good long-term durability. Over the past 15 years, the frequency of surgical clipping for basilar tip aneurysms has decreased, and the procedure may eventually be abandoned for this type of aneurysm. However, surgical clipping still offers several advantages in the treatment of paraclinoid aneurysms.Hybrid neurosurgeons can make reasonable decisions concerning the choice of treatment for cerebral aneurysms, as they perform both treatments and understand the benefits and drawbacks of each modality.

The superficial temporal artery to middle cerebral artery (STA-MCA) bypass procedure has continually evolved and new strategies have been advocated to reduce anesthetic or surgical mortality and morbidity. Further simplifying and decreasing the invasiveness of STA-MCA bypass by performing this operation without endotracheal general anesthesia was deemed feasible in certain subsets of patients.We performed STA-MCA bypass using local anesthesia using a sedative in 45 patients with hemodynamically compromised cerebrovascular occlusive disease as well as multiple comorbidities in the period between February 2010 and April 2016. The technique is based on preoperative identification of the point at which the donor and recipient vessels are in closest proximity. The preoperative use of computed tomography angiography allowed us to identify the target point precisely and use a minimally invasive procedure. All patients received dexmedetomidine as the sole sedative agent, together with scalp block local anesthesia with an unsecured airway.Successful STA-MCA bypass surgeries were achieved via a preselected minimally invasive approach in all cases. There was good hemodynamic stability throughout surgery. No airway/ventilation complications occurred and no patient was converted to general anesthesia. The patients subjectively tolerated this technique well with a high rate of satisfaction. Postoperative magnetic resonance angiography confirmed patent bypass in 44 of 45 patients (patency rate of 97.8%). There were two postoperative hyper-perfusion syndromes and one cerebral ischemia with transient neurological symptoms (postoperative complication rate of 6.3%). No recurrence of ipsilateral cerebral ischemia was observed during the follow-up periods. There was one contralateral cardiogenic cerebral embolism during the follow-up period. The overall stroke rate was calculated as 1%/patient/year.Our initial experience confirms the feasibility of performing STA-MCA bypass under local anesthesia without endotracheal general anesthesia.

The surgical treatment of intrinsic brainstem lesions remains a major challenge. In this article we present the results of using an infratentorial-supracerebellar (ITSC) approach for the resection of intrinsic ponto-mesencephalic lesions.The authors reviewed the cases of 16 patients. In seven of them, a paramedian ITSC transcollicular approach was used to resect intrinsic mid-brain lesions, and in the other nine patients, an intermediate or lateral ITSC infra-trochlear approach was used for ponto-mesencephalic lesions.All 16 lesions were completely removed. There was no recurrence of bleeding during the follow-up period, and no mortality. In seven patients with mid-brain lesions, the preoperative ocular symptoms improved in three of them, and the neurological deficits - other than ocular symptoms improved - in five of them. The preoperative modified Rankin Scale score of 1.8 improved to 1.3 postoperatively. In nine patients with a ponto-mesencephalic lesion, the preoperative ocular symptoms improved in four of nine patients, and the neurological deficits other than ocular symptoms improved in five of them, while one patient exhibited venous infarction in a cerebellar hemisphere that caused neurological deterioration. The preoperative modified Rankin Scale score of 3.75 improved to 2.5 postoperatively in these patients.The ITSC transcollicular or infra-trochlear approach provide a wide operative entry zone and minimize the functional damage to the surrounding structures for access to ponto-mesencephalic lesions.

Cerebral revascularization strategies may become necessary in select patients who present with challenging cerebral aneurysms. In this study, we present the techniques of a moderate-flow extra-intracranial bypass using a short interposition vein graft and concurrent aneurysm management.The short interposition vein graft was used for the reconstruction of complex cerebral aneurysms in nine patients. In eight of them, the superficial temporal artery (STA) main trunk was used as a donor site for the anastomosis of a short interposition vein graft, and an extracranial vertebral artery (VA) was used in one case. The vein grafts were implanted into the M2 of the middle cerebral artery (MCA) for the adjunctive treatment of internal carotid artery (ICA) aneurysms in three patients, into the A3 of the anterior cerebral artery (ACA) in one patient, into the P2 of the posterior cerebral artery (PCA) for the adjunctive treatment of complex PCA aneurysms in three patients, into the P3 of the PCA for the adjunctive treatment of a basilar artery (BA) trunk giant aneurysm in 1 patient, and into the postero-inferior cerebellar artery (PICA) for the adjunctive treatment of the VA dissecting aneurysm in one patient.All of the bypasses were patent. Intraoperative flow measurements confirmed a moderate flow-carrying capacity of the short interposition short vein graft (30-70 ml; mean: 43 ml/min).The STA main trunk to proximal MCA/PCA bypass and the extracranial VA to PICA bypass using short interposition vein grafts can provide sufficient blood flow and may be a reasonable alternative to the conventional EC-IC bypass/high-flow bypass.

Superficial temporal artery (STA) is the mainstay of donor vessels for extra-intracranial bypass (EC-IC bypass) in cerebral revascularization. However, the typically used STA frontal or parietal branch is not always adequate in its flow-carrying capacity. In the present study, we provide an update on an alternative strategy: the use of the STA main trunk as a donor vessel, with a short vein interposition graft.Seven patients in whom the STA main trunk was used as a donor site for anastomosis of a short interposition vein graft were included. The grafts were implanted into the M2 of the middle cerebral artery for adjunctive treatment of IC anterior wall blood-blister aneurysms in two patients, for revascularization of an internal carotid artery occlusion in one patient, into the P2/3 of the posterior cerebral artery (PCA) for adjunct treatment of complex PCA aneurysms in three patients and into the P3 of PCA for adjunct treatment of basilar artery (BA) trunk giant aneurysm in one patient.All the bypasses were patent. Intraoperative flow measurements confirmed a moderate flow-carrying capacity of the STA main trunk-interposition short vein graft (20-50 ml; mean 43 ml/min).The STA main trunk has a larger diameter than the distal branch; therefore, it would be expected to have a significantly higher flow capacity than its branches. STA main trunk to proximal MCA/PCA bypass using short interposition vein grafts can provide sufficient blood flow, and may be a reasonable alternative to ECA to MCA/PCA bypass using long vein grafts.

Recent advances in neurosurgery and interventional neuroradiology have brought us a new aspect in the treatment of cerebral aneurysms. The present single-surgeon series provides a balanced overview of the treatment of ruptured aneurysms in surgical clipping and coil embolization.One hundred consecutive patients with ruptured cerebral aneurysms underwent surgical clipping or endovascular coil embolization between January 2005 and December 2007. All patients underwent clipping or coil embolization of at least one ruptured cerebral aneurysm by a single neurosurgeon (YK) who performed both the surgical clipping and endovascular coiling.Of the 48 surgically treated patients, 37 (77.1%) achieved a favorable outcome. Of the 52 patients who underwent endovascular embolization, 37 (71.2%) achieved a favorable outcome. No significant difference was observed regarding the proportion of favorable outcomes between the two treatment modalities. Five patients (9.6%) who underwent endovascular embolization needed re-treatments, while no re-treatment was necessary in the surgically treated patients. The rates of symptomatic vasospasm and shunt dependent hydrocephalus were 18.8% and 14.6%, respectively, in the clipped patients, and 19.2% and 21.2%, respectively, in the coiled patients. Endovascular coiling of ruptured aneurysms has a tendency towards a higher risk of developing shunt dependent hydrocephalus.A combined microsurgical-endovascular approach can achieve the best outcomes for patients with ruptured cerebral aneurysms. Our findings support the policy of "Clip and Coil, not Clip versus Coil."