Ryokichi Yagi

Dissection of both frontal and parietal branches of the superficial temporal artery for bypass surgery through a single linear skin incision

BackgroundDouble superficial temporal artery (STA) to middle cerebral artery (MCA) bypass surgery has typically involved more than one linear incision. In this report, we demonstrate how the procedure can be performed through a single linear skin incision over the parietal branch of the STA.MethodsInitial dissection of the parietal branch and creation of a subcutaneous cavity along the frontal branch were performed using the conventional microscopic method. Detailed additional dissection and isolation of the frontal branch were accomplished with the aid of an endoscopic retractor.ResultsThis procedure was performed in five patients for harvesting of approximately 8- and 5-cm lengths of the parietal and frontal branches, respectively. The resultant lengths of the harvested vessels were sufficient for anastomotic revascularization of MCA recipient arteries in both the frontal and temporal lobes.ConclusionThis method can be safely performed with achievement of a less invasive dissection of the STA and an overall improved cosmetic outcome.

Tied Pipeline: A Case of Rare Complication

A 48-year-old female with a symptomatic giant carotid cavernous aneurysm underwent endovascular treatment with multiple Pipeline Flex embolic devices (PED). The delivery catheter had to take a complicated course of multiple turns to cross the aneurysm, and its loop was tied in the aneurysm. When the catheter was to be withdrawn, it was apparent that the tied catheter had made a tight knot that bound the tail of the previous PED together. We successfully retrieved all of the system including the tied PED, and we used telescoping stents with five PEDs in the next operation. Although this is a rare complication, it is worth noting and checking to make sure that there is no knot before deploying the stent.

Limit of intraoperative near-infrared spectroscopy monitoring during endovascular thrombectomy in acute ischemic stroke

Endovascular thrombectomy is recommended for a persistent ischemic penumbra if recanalization cannot be achieved by the intravenous (IV) administration of recombinant tissue-plasminogen activator (rt-PA) alone. Although endovascular thrombectomy is a powerful treatment for major cerebral artery occlusion, the monitoring of recanalization and reperfusion during acute ischemic stroke presents a therapeutic challenge, and a previous study reported the usefulness of near-infrared spectroscopy (NIRS) for intraoperative monitoring during emergency endovascular thrombectomy for acute large ischemic stroke. Here we present our experience with a relevant case series. We applied NIRS monitoring during endovascular thrombectomy in two patients with large ischemic stroke following carotid artery occlusion and one patient with a non-large ischemic stroke caused by a distal middle cerebral artery (MCA) occlusion. In the patients with large ischemic stroke, complete recanalization of the internal carotid artery was achieved, and NIRS revealed a very good regional oxygen saturation (rSO2) response. By contrast, in the patient with non-large ischemic stroke, the rSO2 did not change, despite complete recanalization of the distal MCA. Our findings suggest the limited usefulness of intraoperative NIRS monitoring during emergency endovascular thrombectomy for non-large acute ischemic stroke caused by a distal MCA occlusion. However, intraoperative NIRS monitoring could be used practically to detect recanalization of the major artery during thrombectomy and early IV rt-PA administration in cases involving major artery occlusion.

Usefulness of the Pipeline Embolic Device for Large and Giant Carotid Cavernous Aneurysms

Purpose Conventional coil embolization for large carotid cavernous aneurysms (CCAs) has limited utility due to its inability to prevent recurrences and reduce mass effect. Trapping of the parent artery may have a risk of ischemic complications due to intracranial perfusion disorders. We successfully treated 24 patients with large CCAs using a flow diverter (Pipeline™ embolic device: PED), and this report discusses the safety and efficacy of this method. Materials and Methods Twenty four patients (23 females, mean age 71.5 years old) with large CCAs, including 6 giant CCAs, were treated with a PED over three years. Under sufficient dual anti-platelet management, the PED was deployed over the orifice of the aneurysm. Two patients required multiple telescoping stents. Clinical and radiological states were checked with MRI at 1, 3 and 6 months post-surgically. Angiographic follow-up was performed at 6 months. Results In all patients, PED was appropriately deployed. Stagnation of contrast with eclipse signs was observed post-angiogram in 21 cases. One patient requiring 5 telescoping stents experienced temporary ischemic symptoms. Fourteen patients experienced improvement of ocular motor impairment deficiency, including 6 patients who recovered. Angiograms at 6 months follow-up showed complete occlusion in 63% (12/19) of patients, and MRI showed reduction of aneurysm volume in 89% (17/19) of patients. Conclusion Flow diverters for large CCAs showed promising clinical and radiological efficacy. They can shrink the aneurysm and improve symptoms without sacrificing the parent artery. It will be necessary to summarize the cases and to verify the long-term results.