Efficacy of Carotid Endarterectomy for Mild (<50%) Symptomatic Carotid Stenosis with Unstable Plaque.

BACKGROUND: Carotid endarterectomy (CEA) is known to reduce stroke risk in patients with symptomatic, moderate to severe carotid stenosis but has no apparent impact in patients with symptomatic, mild (less than 50%) carotid stenosis. However, recent development of noninvasive imaging modalities has shown that a certain subgroup of patients are at high risk for further ischemic events despite antiplatelet therapy. This study, therefore, aimed to clarify the patients' clinical features and explore the impact of CEA for them. METHODS: This prospective cohort study included 74 patients who underwent CEA for symptomatic carotid stenosis between April 2012 and December 2016. Of these, 16 (22%) had mild (less than 50%) carotid stenosis. Their demographic, radiologic, intraoperative, and pathologic findings were precisely analyzed, and their outcome after CEA was examined for 38.5 ± 13.3 months. RESULTS: Of these 16 patients, 12 had already been treated with antiplatelets against previous ischemic cerebrovascular or coronary artery diseases. Plaque magnetic resonance imaging revealed that all patients had vulnerable plaque, including lipid-rich plaque (n = 6) and intraplaque hemorrhage (n = 10). Intraoperative observations confirmed this. Histologic analysis revealed that inflammatory cells and fragile angiogenesis were widely found in the specimens. Only 1 patient experienced transient (less than 30 days) neurologic deficit after CEA, and none of them repeated cerebrovascular events during the follow-up period. CONCLUSIONS: It is not rare the patients who are at high risk for subsequent ischemic events because of vulnerable plaque despite mild (less than 50%) carotid stenosis. Magnetic resonance imaging is quite useful to noninvasively detect such vulnerable plaque. CEA is a promising procedure to treat these patients.

Persistent Primitive Olfactory Artery as Novel Collateral Channel to the Anterior Cerebral Artery in Moyamoya Disease.

BACKGROUND: There are a variety of collateral routes to compensate persistent cerebral ischemia in moyamoya disease. However, there is no report presenting the persistent primitive olfactory artery (POA) as a spontaneous collateral route to the anterior cerebral artery (ACA) in moyamoya disease. METHODS: We precisely examined cerebral angiography in 84 patients with moyamoya disease to identify the collateral channel through the persistent POA. Its anatomy was evaluated on pre- and postoperative angiography. RESULTS: Of 84 patients, four (4.8%) had spontaneous collateral channel through the persistent POA. All of these four hemispheres were categorized into Stage 5. In all four patients, the collateral blood flow arose from the ophthalmic artery and run to the persistent POA through the ethmoidal moyamoya. The persistent POA provided collateral blood flow from the ophthalmic artery to the ACA in all four patients. Superficial temporal artery to middle cerebral artery anastomosis and encephalo-duro-myo-arterio-pericranial synangiosis was performed in three of four patients. After surgery, the collateral channel through the persistent POA completely disappeared or markedly regressed, suggesting a significant improvement of cerebral hemodynamics in the territory of not only the MCA but also the ACA. CONCLUSION: The persistent POA can potentially provide collateral blood flow to the ACA in about 5% of patients with moyamoya disease, and should be recognized as a novel collateral channel in moyamoya disease. The persistent POA may be useful to evaluate therapeutic effects of surgical revascularization on the ACA territory.

[Clinical Features and Findings in Patients with Unruptured Intracranial Aneurysms Aged ≥80 Years].

OBJECTIVE: It is difficult to decide whether to treat unruptured intracranial aneurysm(UIA)in elderly patients aged ≥80 years because they have potentially shorter life expectancy and risks related to treatment. Here, we report the results of the treatment of patients aged ≥80 years. METHODS: A retrospective review was performed in patients who underwent surgical or endovascular treatment between April 2012 and December 2015 at our institution. RESULTS: Between April 2012 and December 2015 we treated 130 UIA patients who presented with 145 aneurysms and 12 patients who presented with 14 aneurysms, who were aged ≥80 years. One patient was male and the others were female. Their mean age was 81.9 years(range: 80-88 years). The aneurysms included ICA aneurysms(n=6), ACA aneurysms(n=1), MCA aneurysms(n=4), and BA aneurysms(n=3). The maximum sizes of the aneurysms were ≤5mm(n=3), 5-10mm(n=8), and ≥10mm(n=3). The reasons for treatment were as follows: symptomatic aneurysms(n=2), strong desire of the patient to treat their aneurysms(n=4), high risk of rupture because of the morphology of the aneurysm(n=4), concomitant presentation with a ruptured aneurysm(n=1), and recurrence after coil embolization(n=1). In the endovascular treatment we used dual anti-platelet drugs in all cases and a stent device in 3 cases. In all cases, we used general anesthesia. There were no complications during the operations or ischemic or hemorrhagic events after surgery. We identified subcutaneous hematoma at the puncture site in 2 cases. The modified Rankin Scale(mRS)score of no patient worsened compared to their preoperative mRS score. The average length of hospital stay was 31 days. In comparison with patients aged ≤79 years, there was no significant worsening of the mRS score. In patients aged ≥80 years, the length of their hospital stay was longer than that of younger patients. CONCLUSION: While caution is warranted when treating UIA patients aged ≥80 years, our findings for the treatment of aged patients were noteworthy. This treatment is meritorious if the indications are well considered and an experienced physician performs the operation. However, there are problems associated with using anti-platelet drugs in elderly patients.

[Hemorrhage from an Angiographically Obliterated Arteriovenous Malformation after Gamma Knife Radiosurgery:An Immunohistochemistry Study].

A 24-year-old woman was diagnosed with a cerebral arteriovenous malformation(AVM)in the right parietal lobe(Spetzler-Martin grade I). The AVM was treated with stereotactic radiosurgery and was observed to have completely disappeared 3 years after radiosurgery. At the age of 35 years, the patient complained of a headache, and was referred to our hospital. A plain CT scan demonstrated a large cyst with niveau formation in the right parietal lobe. Cerebral angiography identified no recurrence of AVM. However, contrast MRI revealed an enhanced lesion on the surface of the cyst. The patient underwent cyst fenestration and total removal of the obliterated nidus through a right parietal craniotomy. Residual blood flow was confirmed in the obliterated nidus during surgery. The postoperative course was uneventful, and the headache was completely resolved. The patient was discharged without any neurological deficits. On pathological examination, a large number of small vessels were observed within the obliterated nidus. Immunohistochemistry demonstrated that these vessels were positive for CD31, CD34, and VEGFR-2, suggesting that endothelial progenitor cells may be involved in occult recurrence, cyst formation, and late bleeding after stereotactic radiosurgery targeting cerebral AVMs.

[Usefulness of Tablet-Type Device Usage during Neurosurgical Practice].

This study aimed to validate the usefulness of intraoperative use of a tablet-type device in neurosurgical field. This study included 80 patients who underwent direct surgery for complex brain and spinal disorders in our hospital between April 2013 and March 2015. The operated disorders included cerebral aneurysm, intracranial and spinal dural arteriovenous fistula, meningioma, and vestibular schwannoma. By using the OsiriX HD software, the DICOM data were directly transferred to a tablet-type device (Apple iPad). Alternatively, by using the OsiriX HD or Amira software, the DICOM data were loaded to create interactive three-dimensional computer graphics on a personal computer and then transferred to a tablet-type device. The device was covered with sterile, translucent packaging bag. As a result, the surgeons could use the touch screen to browse and access radiological data of the patient undergoing surgery, without needing to leave the operation field or requiring external assistance for image browsing. The incidence of postoperative infection did not increase. In conclusion, intraoperative usage of the tablet-type device was easy and useful for surgeons performing surgeries for complex brain and spinal disorders.