Ayumi Nishida

Determinants of Poor Outcome After Aneurysmal Subarachnoid Hemorrhage when both Clipping and Coiling Are Available: Prospective Registry of Subarachnoid Aneurysms Treatment (PRESAT) in Japan

OBJECTIVE To examine current determinants of poor outcome after aneurysmal subarachnoid hemorrhage (SAH) when ruptured aneurysms are treated with either microsurgery (clipping) or endovascular treatment (coiling) depending on each patients characteristics. METHODS Between March 2006 and February 2007, 534 patients with SAH were enrolled in the Prospective Registry of Subarachnoid Aneurysms Treatment (PRESAT) project. Patients were treated according to the preference of investigators who were experienced in performing both clipping and coiling. Factors influencing poor outcome (12-month modified Rankin Scale [mRS], 3-6) were determined using multivariate logistic regression analyses. RESULTS In this cohort, 32.4% of patients were World Federation of Neurosurgical Societies (WFNS) grade IV-V, and 28.1% had a poor outcome. Clipping was preferably performed for small aneurysms with a wide neck and for middle cerebral artery (MCA) aneurysms, whereas coiling was preferred for larger, internal carotid artery (ICA) and posterior circulation aneurysms. In addition to increasing age, admission WFNS grade IV-V, preadmission aneurysmal rerupture, vasospasm-induced cerebral infarct, pneumonia, sepsis, shunt-dependent hydrocephalus and seizure, postclipping hemorrhagic complications (odds ratio 4.8, 95% confidence interval 1.5-15.3, P < 0.01), and postcoiling ischemic complications (odds ratio 4.4, 95% confidence interval 1.3-15.2, P < 0.05) significantly caused poor outcomes, although the complications did not affect mortality. Type of treatment modality and size and location of aneurysms did not influence outcome. CONCLUSIONS Introducing an endovascular treatment option has made aneurysm characteristics less important to outcome, but procedural complications are problematic and should be reduced to improve outcome.

Endovascular treatment for bow hunter's syndrome: case report.

INTRODUCTION Bow hunters syndrome is a unique clinical entity caused by mechanical occlusion of the vertebral artery on head rotation. Although it is usually treated by direct surgical intervention, we report successful treatment using endovascular stent placement for contralateral vertebral artery stenosis. CASE DESCRIPTION A 56-year-old man presented with repeated vertigo and loss of consciousness caused by turning his head to the left. Right vertebral angiogram showed no abnormalities with the head in the neutral position. However, with the head rotated 60 degrees to the left, the right vertebral artery was completely occluded at the C1-2 level. A three-dimensional angiogram with bone window clearly demonstrated vertebral artery compression at the C1-2 level by the bony structure. The left subclavian angiogram revealed severe stenosis at the origin of the left vertebral artery. Left vertebral artery angioplasty followed by stent placement was successfully performed under local anesthesia. The patient showed an uneventful postoperative course and his preoperative symptoms disappeared. At 6 months postoperatively, a left subclavian angiogram showed good patency of the stented left vertebral artery and the patient showed no recurrent symptoms. CONCLUSION Vertebral artery stenting is a useful and less invasive option in the treatment of bow hunters syndrome in the setting of contralateral vertebral artery stenosis.

Computational fluid dynamics of carotid arteries after carotid endarterectomy or carotid artery stenting based on postoperative patient-specific computed tomography angiography and ultrasound flow data.

BACKGROUND:There are significant differences in the postoperative morphological and hemodynamic conditions of the carotid arteries between carotid artery stenting (CAS) and endarterectomy (CEA). OBJECTIVE:To compare the postoperative rheological conditions after CAS with those after CEA with patch angioplasty (patch CEA) through the use of computational fluid dynamics (CFD) based on patient-specific data. METHODS:The rheological conditions in the carotid arteries were simulated in 2 patients after CAS and in 2 patients after patch CEA by CFD calculations. Three-dimensional reconstruction of the carotid arteries was performed with the images obtained with computed tomography angiography. The streamlines and wall shear stress (WSS) were calculated by a supercomputer. Adequate boundary conditions were determined by comparing the simulation results with ultrasound flow data. RESULTS:CFD was successfully calculated for all patients. The differences between the flow velocities of ultrasound data and those of the simulation results were limited. In the streamline analysis, the maximum flow velocities in the internal carotid artery after patch CEA were around two-thirds of those after CAS. Rotational slow flow was observed in the internal carotid artery bulb after patch CEA. WSS analysis found regional low WSS near the outer wall of the bulb. High WSS was observed at the distal end of the arteriotomy after patch CEA and at the residual stenosis after CAS. CONCLUSION:CFD of postoperative carotid arteries disclosed the differences in streamlines and WSS between CAS and patch CEA. CFD may allow us to obtain adequate rheological conditions conducive to achieving the best clinical results.

Effectiveness of intraoperative near-infrared indocyanine green videoangiography in a case with recurrent spinal perimedullary arteriovenous fistula

Concerning about the treatment of spinal perimedullary arterivenous fistulas (AVFs), the goal is to obliterate the arteriovenous hunt with the preservation of the normal arterial supply and enous drainage of the spinal cord [1,3]. In order to obliterate the stula, precise identification of the fistulous point is critical. Howver, identification of the fistulous point is occasionally obscured n conventional spinal digital subtraction angiography (DSA) by verlapping dilated veins even in a primary case [3]. In the present ase which recurred at about 8 months after the initial surgery, reoperative spinal DSA could not detect the accurate shunt point ecause the flow of the shunt was low. Intraoperative spinal DSA as considered inadequate for visualizing small vessels associated ith this lesion. Therefore, we decided to utilize intraoperative ICG ideoangiography in order to identify the feeding arteries and the stula. Microscope-integrated indocyanine green (ICG) videoangiogaphy has recently reemerged as an efficient option and been idely performed to assess cerebral vascular flow [4]. To date, ICG ideoangiography has never been performed in a case of spinal erimedullary AVFs. In this report, we show the efficacy of ICG ideoangiography in a case with recurrent spinal perimedullary

Significant differences in the postoperative morphological and hemodynamic conditions of carotid arteries of patients undergoing stenting or endarterectomy with patch angioplasty.

OBJECTIVECarotid endarterectomy with a patch graft (Patch CEA) has been our standard treatment for patients with carotid artery stenosis, but carotid artery stenting (CAS) has emerged as an alternative. The purpose of this study was to compare the postoperative changes in the configurations and the flow velocities of carotid arteries after CAS or Patch CEA. METHODSThirty-one patients undergoing CAS or Patch CEA were included. The pre- and postoperative shapes of the carotid arteries were evaluated by angiography and ultrasonography. Doppler waveforms were recorded in the middle portion of the common carotid artery and in the internal carotid artery bulb to measure flow velocities, including peak systolic, mean, and end-diastolic velocities. RESULTSEighteen patients were treated by CAS, and Patch CEA was performed for 13 patients. Preoperatively, there were no differences in the degrees of stenosis or the flow velocities between the 2 groups. The averages of the diameters of the postoperative internal carotid artery bulbs were 4.5 mm in the CAS group and 7.0 mm in the Patch CEA group (P < 0.01). The averages of peak systolic, mean, and end-diastolic velocities measured in the internal carotid artery were 80, 42, and 25 cm/s, respectively, in the CAS group, and were significantly greater than those (53, 28, and 16 cm/s, respectively) in the Patch CEA group (P < 0.01). CONCLUSIONSignificant differences in postoperative morphological and hemodynamic conditions between CAS and Patch CEA were observed. The impact of these differences will be determined by further studies.

Triple-catheter technique in the transvenous coil embolization of an isolated sinus dural arteriovenous fistula

OBJECTIVE Dural arteriovenous fistulae involving the transverse-sigmoid sinus, which is occluded at its proximal and distal ends (i.e., an isolated sinus), carry a high risk of intracranial hemorrhage or progressive neurological deficits. Although transvenous coil embolization is a useful and safe treatment for such lesions, it is often difficult to reach into the isolated sinus through the occluded sinus using the percutaneous catheter approach. METHODS We report the successful treatment of two patients with transverse-sigmoid dural arteriovenous fistulae with isolated sinus using the percutaneous transvenous triple-catheter technique. A 6-French guiding catheter was placed at the internal jugular vein followed by a second 4-French catheter positioned at the end of the occluded sinus. A third microcatheter was then navigated into the isolated sinus with support of the second catheter. RESULTS Although initial attempts to reach into the isolated sinus without the second catheter failed, insertion of the second catheter resulted in successful navigation of the third microcatheter into the affected sinus in both cases. Complete cure was obtained in both cases by coil packing of the affected sinus. CONCLUSION Although careful maneuvering is required, this triple-catheter technique is useful for treatment of dural arteriovenous fistulae with isolated sinus.

Training in Neurovascular Intervention Usefulness of in-Vitro Model and Clinical Practice

We introduce our training tools and system of neurovascular intervention. An in vitro cerebral vascular model was used for the young residents to understand the basic interventional techniques and devices. The model included several vascular lesions such as cerebral aneurysm, dural arterio-venous fistula, or carotid artery stenosis. Endovascular procedures in the model were performed under fluoroscopic or direct visual control, and consecutive haemodynamic changes were visualized by using digital subtraction angiography and direct observation. Thus, traineess could have an easy understanding of clinical conditions. New medical devices, such as platinum coils, were successfully implanted in the model under stable conditions. After the initial training using vascular model, the residents had started clinical experiences under the control of senior surgeons. Although it is difficult to describe usefulness of our clinical training, we believe that we provide enough good quality and quantity of clinical cases to the residents. Because our endovascular team has recently had 150–200 interventional procedures every year, one resident can have experienced more than 100 cases per year. The qualification of a Board Certified Specialist of the Japanese Society of Intravascular Neurosurgery (JSIN) requires that the applicant must have experienced more than 100 cases for four years. So our residents can have enough case materials to qualify the board examination.

Complications of embolization for cerebral arteriovenous malformations.

Embolization is recognized as an important adjunct in the treatment of cerebral arteriovenous malformations (AVMs). We reviewed our results of embolizations for AVMs and discussed procedure-related complications. Eleven complications were recorded in 68 consecutive patients (16%). Of these, four were technical problems including a glued catheter, inability to withdraw the catheter, vessel perforation by the microcatheter, and coil migration. Other complications included three cases of ischemic symptoms due to retrograde thrombosis, two cases of asymptomatic cerebral infarction, one case of asymptomatic small haemorrhage due to venous occlusion, and one case of post-embolization haemorrhage of unknown etiology. Our morbidity rate was 7%, mortality rate was 0%, and asymptomatic complication rate was 9%, retorospectively. Further improvements to endovascular techniques and devices are required.