Surgical microanatomy of the occipital artery for suboccipital muscle dissection and intracranial artery reconstruction.

BACKGROUND: The occipital artery (OA) is an important donor artery for posterior fossa revascularization. Harvesting the OA is difficult in comparison to the superficial temporal artery because the OA runs between suboccipital muscles. Anatomical knowledge of the suboccipital muscles and OA is essential for harvesting the OA during elevation of the splenius capitis muscle (SPL) for reconstruction of the posterior inferior cerebellar artery. We analyzed the running pattern of the OA and its anatomic variations using preoperative and intraoperative findings. METHODS: From April 2012 to March 2018, we surgically treated 162 patients with suboccipital muscle dissection by OA dissection using the lateral suboccipital approach. The running pattern and relationship between the suboccipital muscles and OA were retrospectively analyzed using the operation video and preoperative enhanced computed tomography (CT) images. The anatomic variation in the running pattern of the OA was classified into two types: lateral type, running lateral to the muscle and medial type, running medial to the longissimus capitis muscle (LNG). RESULTS: The medial pattern was observed in 107 (66%) patients and the lateral pattern in 54 (33.3%); 1 (0.6%) patient had the OA running between the LNGs. CONCLUSION: Preoperative CT is effective in determining the running course of the OA, which is important for safely harvesting the OA during SPL elevation. There is a risk of causing OA injury in patients with the lateral pattern. This is the first report showing that the OA rarely runs in between the LNGs.

[Transarterial Embolization of Intraorbital Dural Arteriovenous Fistula:A Case Report].

Intraorbital dural arteriovenous fistula(dAVF)is a very rare disease; therefore, an optimal treatment strategy has not yet been established. Here, we describe a case of successful dAVF treatment by performing transarterial embolization(TAE)with n-butyl-2-cyanoacrylate(NBCA). A 66-year-old male presented with right conjunctival injection, with no history of trauma. Magnetic resonance imaging(MRI)demonstrated a flow void in the right orbit. Digital subtraction angiography(DSA)revealed an AVF fed by a branch of the right ophthalmic artery(OA)and draining into the dilated right superior ophthalmic vein(SOV). A transvenous embolization(TVE)was planned, but it could not be performed because the facial vein was meandering. Hence, TAE with NBCA was performed, and the AVF was successfully occluded by this method. There has been no recurrence of intraorbital dAVF in three months since the treatment. Several recent studies have reported that TAE is an effective treatment for intracranial dAVF. However, there are insufficient reports of TAE with NBCA for intraorbital dAVF treatment. The anatomy of the OA needs to be known for the success of TAE in treating intraorbital dAVF, because TAE is a high-risk treatment. In this paper, we report a case wherein TAE with NBCA was performed for intraorbital dAVF and further review the other treatment options.

Preoperative Predictors and Prognosticators After Microsurgical Clipping of Poor-Grade Subarachnoid Hemorrhage: A Retrospective Study.

BACKGROUND: Contrary to expectations, some patients with poor-grade subarachnoid hemorrhage (SAH) show favorable outcomes. However, the factors predictive of good prognosis are unclear. The purposes of this study were to identify factors related to poor-grade SAH and to analyze preoperative prognostic factors. METHODS: We included 186 patients with SAH who underwent surgical clipping or conservative treatment immediately after SAH diagnosis. Physiologic, radiographic, and blood examination data were collected retrospectively. Factors related to poor World Federation of Neurological Societies (WFNS) grade (WFNS IV and V) and poor outcome (modified Rankin Scale scores 3-6) were analyzed. RESULTS: The patients (mean age, 61.6 years) included 134 women (72%). Seventy patients (38.2%) had poor WFNS scores. On multivariate analysis, age ≥70 years (adjusted odds ratio [OR], 3.73), midline shift (OR, 4.89), and the absence of cerebrospinal fluid in the high-convexity cortical sulci (OR, 5.47) and ambient cistern (OR, 4.83) were predictive of poor WFNS scores. Age ≥70 years (OR, 8.36), WFNS grade 5 (OR, 15.35), intracerebral hematoma (OR, 3.32), and Evans index (EI) ≥0.3 (OR, 4.40) were predictive of poor outcome. Body mass index (OR, 0.87), intraventricular hemorrhage (OR, 3.86), glycated hemoglobin level (OR, 2.78), and age ≥70 years (OR, 4.12) were predictive of EI ≥0.3. CONCLUSIONS: Poor outcomes correlated with older age, brain-destructive hemorrhage, and EI ≥0.3. The EI reflects both hydrocephalus and the patient's frailty. Radiographic signs of poor-grade SAH were not correlated with poor outcome, suggesting that early decompressive surgery may improve outcome.

Evaluation of Microsurgery for Managing Giant or Complex Cerebral Aneurysms: A Retrospective Study.

OBJECTIVE: Surgical or endovascular treatment for giant or complex aneurysms is challenging. The aims of this study were to evaluate clinical outcomes and factors affecting the prognosis of giant or complex aneurysms and to better establish the role of microsurgery in the management strategy. METHODS: One hundred fifty-nine patients with surgically treated complex aneurysms were included. Thirty-two patients (20.1%) had giant aneurysms (≥25 mm) and 57 (35.8%) had large aneurysms (≥15 mm). Poor outcome was defined as modified Rankin Scale scores of 3-6. RESULTS: The mean aneurysm size was 17.0 mm (range, 1.6-47.5 mm). One hundred and sixteen aneurysms (80.0%) were in the anterior circulation and 43 (27.0%) were in the posterior circulation. One hundred and thirty-eight (86.8%) aneurysms were completely occluded without residual aneurysms. Nineteen (11.9%) had minor aneurysm remnants; 2 (1.3%) had incomplete occlusion. Two patients (1.3%) with giant basilar artery (BA) trunk aneurysms experienced rupture of the treated aneurysm and died. Bypass surgery was combined with microsurgery in 148 patients (93.1%). Perforating artery infarction was observed postoperatively in 42 patients (26.4%), and poor outcome was observed in 29 (18.2%). Male sex (P = 0.016; adjusted odds ratio [OR], 4.524 [1.949-10.500]), perforating artery infarction (P < 0.001; adjusted OR, 13.625 [5.329-34.837]), and BA aneurysm location (P = 0.003; adjusted OR, 56.333 [6.830-464.657]) were significantly related to poor outcome. The aneurysm size (P = 0.017; adjusted OR, 1.064 [1.021-1.107]), C1 aneurysm location (P = 0.042; adjusted OR, 2.591 [0.986-6.811]), and BA aneurysm location (P = 0.033; adjusted OR, 12.956 [3.197-52.505]) were significantly related to perforating artery infarction. CONCLUSIONS: Microsurgery with bypass is effective for many different complex aneurysms, except BA aneurysms.

Preventing Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage with Aggressive Cisternal Clot Removal and Nicardipine.

BACKGROUND: A subarachnoid clot is the strongest predictor of cerebral vasospasm. Our purpose was to analyze the relationship between the number of postoperative cisternal clots and cerebral vasospasm and to assess the efficacy of surgical clot removal. METHODS: The subjects were 158 patients with aneurysmal subarachnoid hemorrhage. All patients underwent clipping with cisternal clot removal. The preoperative and postoperative number of clots was analyzed semiquantitatively using computed tomography, and cerebral vasospasm and its severity were analyzed using magnetic resonance angiography in a blind fashion. Factors related to cerebral vasospasm and poor outcome were analyzed retrospectively. Poor outcome was defined as modified Rankin Scale (mRS) score of 3 or greater. RESULTS: Symptomatic cerebral vasospasm (SCV) was observed in 6 patients (3.8%). Angiographic vasospasm (AVS) was observed in 38 patients (24.1%). One year after the operation, 82.9% of patients had an mRS score of 0-2. The postoperative number of clots was significantly (P < 0.005) related to SCV (adjusted odds ratio [OR], 6.447; 95% confidence interval [CI], 2.063-20.146), AVS (OR, 2.634; 95% CI, 1.467-4.728), and poor outcome (OR, 2.103; 95% CI, 1.104-4.007). Poor outcome was also related to age over 65 (OR, 6.658; 95% CI, 2.389-18.559) and World Federation of Neurosurgical Societies scale grade (OR, 1.732; 95% CI, 1.248-2.403). CONCLUSIONS: Surgically removing as many clots as possible in the acute stage can decrease SCV and reduce AVS severity. Irrigation should be performed on all approachable cisterns.

Endovascular Therapy for a Post-irradiated Cervical Pseudoaneurysm at the Carotid Stump: A Case Report.

A nearly 80-year-old man with a history of radiotherapy (RT) and total laryngectomy for laryngeal cancer 25 years previously presented with a rapidly growing mass on the right side of his neck. A huge pseudoaneurysm (pseudoAN) was detected at the right carotid bifurcation, though angiography performed four years previously had shown total occlusion of the internal carotid artery. Stent-assisted coil embolization enabled aneurysm sac shrinkage. Clinicians must be aware that the stump of an arterial occlusion associated with RT can change into a pseudoAN over the long term and must provide follow-up in such cases.

Assessment of Hemodynamic Compromise Using Computed Tomography Perfusion in Combination with 123I-IMP Single-Photon Emission Computed Tomography without Acetazolamide Challenge Test.

OBJECTIVES: The acetazolamide challenge test in conjunction with 123I-IMP single-photon emission computed tomography (SPECT) is a known method of assessing cerebrovascular reserve capacity. In this study, we investigated whether CT perfusion in combination with resting state 123I-IMP SPECT could be used instead of the acetazolamide challenge test to evaluate hemodynamic compromise in patients with atherosclerotic occlusive disease. METHODS: Twenty consecutive patients with unilateral internal carotid artery or middle cerebral artery steno-occlusive disease were enrolled. 123I-IMP SPECT was performed with and without the acetazolamide challenge test, and with CT perfusion. Cerebral blood flow (CBF), cerebral blood volume, and mean transit time (MTT) obtained by CT perfusion were compared with CBF and cerebrovascular reactivity (CVR) obtained by 123I-IMP SPECT. RESULTS: The asymmetry ratio of MTT as measured by CT perfusion showed a strong correlation with the CVR to acetazolamide as measured by 123I-IMP SPECT (ρ = -.780, P <.001). Based on the CBF obtained through 123I-IMP SPECT and the MTT obtained through CT perfusion, hemodynamic compromise was detected with high sensitivity (1.000) and specificity (.929), and a cutoff value of 30% was found to be suitable for the asymmetry ratio of MTT. MTT prolongation was significantly improved after revascularization surgery in hemodynamic compromise (P = .028). CONCLUSION: MTT as measured by CT perfusion in combination with CBF as measured by resting state 123I-IMP SPECT may be useful for evaluating hemodynamic compromise as an alternative to the acetazolamide challenge test.