A Case of Delayed Intraparenchymal Hemorrhage Due to Hyperperfusion After Flow Diverter Treatment.

Delayed intraparenchymal hemorrhage (DIPH) is one of the complications of flow diverter (FD) treatment, however, the mechanism is unclear. We present the case of a 54-year-old woman with a partially thrombosed large internal carotid artery aneurysm. She presented intraparenchymal hemorrhage in the right parietal lobe three days after the successful FD treatment. We performed endoscopic hematoma removal, and then her consciousness disturbance was fully recovered. IMP single-photon emission computed tomography showed significant increase of cerebral blood flow in the right hemisphere. We diagnosed DIPH associated with hyperperfusion after FD treatment. It is necessary to consider that DIPH due to hyperperfusion may occur after FD treatment.

Hemodynamic differences determining rupture and non-rupture in middle cerebral aneurysms after growth.

BACKGROUND AND PURPOSE: Intracranial aneurysm growth is a significant risk factor for rupture; however, a few aneurysms remain unruptured for long periods, even after growth. Here, we identified hemodynamic features associated with aneurysmal rupture after growth. MATERIALS AND METHODS: We analyzed nine middle cerebral artery aneurysms that grew during the follow-up period using computational fluid dynamics analysis. Growth patterns of the middle cerebral artery aneurysms were divided into homothetic growth (Type 1), de novo bleb formation (Type 2), and bleb enlargement (Type 3). Hemodynamic parameters of the four ruptured aneurysms after growth were compared with those of the five unruptured aneurysms. RESULTS: Among nine aneurysms (78%), seven were Type 1, one was Type 2, and one was Type 3. Three (43%) Type 1 aneurysms ruptured after growth. Maximum oscillatory shear index after aneurysmal growth was significantly higher in ruptured Type 1 cases than in unruptured Type 1 cases (ruptured vs. unruptured: 0.455 ± 0.007 vs. 0.319 ± 0.042, p = 0.003). In Type 1 cases, a newly emerged high-oscillatory shear index area was frequently associated with rupture, indicating a rupture point. Aneurysm growth was observed in the direction of the high-pressure difference area before enlargement. In Types 2 and 3 aneurysms, the maximum oscillatory shear index decreased slightly, however, the pressure difference values remain unchanged. In Type 3 aneruysm, the maximum OSI and PD values remained unchanged. CONCLUSIONS: This study suggests that hemodynamic variations and growth pattern changes are crucial in rupture risk determination using computational fluid dynamics analysis. High-pressure difference areas may predict aneurysm enlargement direction. Additionally, high maximum oscillatory shear index values after enlargement in cases with homothetic growth patterns were potential rupture risk factors.

One-Stage Combined Open and Endovascular Treatment Using a Hybrid Operating Room is Safe and Effective for Distal Middle Cerebral Artery Aneurysms.

BACKGROUND: Aneurysms located in the distal middle cerebral artery (DMCA) are relatively rare and lack an established treatment strategy. For DMCA aneurysms, we performed a one-stage combined procedure of endovascular parent artery occlusion (PAO) with coils and superficial temporal artery to middle cerebral artery (STA-MCA) bypass in a hybrid operating room (HOR). The aim of this study was to evaluate the safety and efficacy of this procedure. METHODS: Cases of unruptured DMCA aneurysms treated with the one-stage combined PAO and STA-MCA bypass in HOR were retrospectively examined, and patients' and aneurysmal backgrounds, surgical procedures, and treatment outcomes were analyzed. RESULTS: Six patients were included in the study. The average maximum diameter of the aneurysms was 14.4 mm. One aneurysm was located at M2 and five at M3. All aneurysms had a fusiform shape. No cases were associated with infection, trauma, or malignant tumors. In all 6 cases, the combined PAO and STA-MCA bypass was successfully completed. No postoperative hemorrhagic complications occurred. A symptomatic ischemic complication occurred in 1 case whose symptom disappeared in a week. Three months after surgery, complete obliteration of the aneurysm and patency of the bypass was confirmed in all cases. CONCLUSIONS: The one-stage combined PAO and STA-MCA bypass in the HOR is safe and effective for DMCA aneurysms, potentially serving as a treatment option for this complex aneurysm.

Open Retrograde Stenting with a Sheathless Method Using a Balloon-guiding Catheter for Proximal Common Carotid Artery Stenosis.

Objective: Carotid artery stenting (CAS) and carotid endarterectomy are relatively difficult for proximal common carotid artery (CCA) stenosis because of the difficulty in anatomical approach. We treated proximal CCA stenosis by retrograde stenting using a 9Fr Optimo for peripheral intervention with a sheathless method. Case Presentation: A 60-year-old woman was scheduled for total arch replacement (TAR) for an aortic arch aneurysm. Preoperative cervical MRI incidentally revealed tandem stenosis in the left CCA. We intended to treat CCA stenosis prior to aortic arch replacement. Under general anesthesia, distal left CCA was exposed. A 9Fr Optimo was introduced into CCA by retrograde with a sheathless method. The retrograde CAS was performed under distal balloon protection. Her postoperative course was uneventful. Conclusion: Retrograde stenting using a 9Fr Optimo for peripheral intervention with a sheathless method was safe and useful for proximal CCA stenosis.