Masahiro Nishihori

Evaluation for shunted pouches of cavernous sinus dural arteriovenous fistula and the treatment outcome of transvenous embolization

Background This study aimed to evaluate the detailed location and the number (single or multiple) of cavernous sinus dural arteriovenous fistula (CSDAVF) shunted pouches as well as the relationship between the characteristics of shunted pouch(es) and the treatment outcome of transvenous embolization for CSDAVF. Methods A total of 23 consecutive patients with CSDAVFs who underwent angiogram and transvenous embolization were retrospectively analyzed. Shunted pouches were assessed using three-dimensional angiogram and multiplanar reformatted image obtained from the rotational angiogram data. Results Of the 23 patients with CSDAVFs, 40 shunted pouches were identified. Twelve CSDAVFs had a single shunted pouch, and 11 had multiple shunted pouches. The mean CSDAVF with multiple shunted pouches was 2.5. The shunted pouches were more often found in the posterior compartment of the CS, which was connected with the intercavernous sinus (23/40; 57.5%). In 12 CSDAVFs with a single shunted pouch, 10 were treated with selective embolization and complete occlusion was achieved during the follow-up. Two CSDAVFs with single shunted pouch were just observed without intervention, and DAVFs disappeared spontaneously during the follow-up period. In 11 CSDAVFs with multiple shunted pouches, eight were treated with selective embolization and three with sinus embolization. In six of eight (75%), complete occlusion was achieved following selective embolization, but two of eight (25%) recurred and required retreatment. Conclusions Rotational angiography data suggested that the shunted pouches of CSDAVFs were mostly located in the posterior compartment of the CS connected with the intercavernous sinus. Selective embolization for CSDAVFs with a single shunted pouch is the first-line treatment alternative to sinus packing, and selective embolization with multiple shunted pouches will be a considerable treatment option.

Intraoperative evaluation of local cerebral hemodynamic change by indocyanine green videoangiography: prediction of incidence and duration of postoperative transient neurological events in patients with moyamoya disease

OBJECTIVETransient neurological events (TNEs) occur frequently in the acute phase after direct bypass surgery for moyamoya disease (MMD), but there is currently no way to predict them. FlowInsight is a specialized software for analyzing indocyanine green (ICG) videoangiography taken with a surgical microscope. The purpose of this study was to investigate whether intraoperative evaluation of local hemodynamic changes around anastomotic sites using FlowInsight could predict the incidence and duration of TNEs.METHODSFrom patients who were diagnosed with MMD in our hospital between August 2014 and March 2017 and who underwent superficial temporal artery-middle cerebral artery bypass surgery, we investigated 25 hemispheres (in 22 patients) in which intraoperative ICG analysis was performed using FlowInsight. To evaluate the local cerebral hemodynamics before and after anastomosis, regions of interest were set at 3 locations on the brain surface around the anastomotic site, and the mean cerebral blood flow (CBF), mean gradation (Grad), mean transit time (MTT), and mean time to peak (TTP) were calculated from the 3 regions of interest. Furthermore, the change rate in CBF (ΔCBF [%]) was calculated using the formula (postanastomosis mean CBF - preanastomosis mean CBF)/preanastomosis mean CBF. ΔGrad (%), ΔMTT (%), and ΔTTP (%) were similarly calculated.RESULTSPostoperative stroke without TNE occurred in 2 of the 25 hemispheres. These 2 hemispheres (in 2 patients) were excluded from the study, and data from the remaining 23 hemispheres (in 20 patients) were analyzed. For each parameter (ΔCBF, ΔGrad, ΔMTT, and ΔTTP) calculated by FlowInsight, the difference between the groups with and without TNEs was significant. The median values for ΔCBF and ΔGrad were significantly higher in the TNE group than in the no-TNE group (ΔCBF 30.13 vs 3.54, p = 0.0106; ΔGrad 62.05 vs 10.78, p = 0.00435), whereas the median values for ΔMTT and ΔTTP were significantly lower in the TNE group (ΔMTT -16.90 vs -7.393, p = 0.023; ΔTTP -29.07 vs -7.02, p = 0.00342). Comparison of the area under the curve (AUC) for each parameter showed that ΔTTP had the highest AUC and was the parameter with the highest diagnostic accuracy (AUC 0.857). The Youden index revealed that the optimal cutoff value of ΔTTP was -11.61 (sensitivity 77.8%, specificity 71.4%) as a predictor of TNEs. In addition, Spearmans rank correlation coefficients were calculated, and ΔCBF, ΔGrad, ΔMTT, and ΔTTP each showed a strong correlation with the duration of TNEs. The larger the change in each parameter, the longer the TNEs persisted.CONCLUSIONSIntraoperative ICG videoangiography findings were correlated with the occurrence and duration of TNEs after direct bypass surgery for MMD. Screening for cases at high risk of TNEs can be achieved by ICG analysis using FlowInsight.

Experimental study of the characteristics of various types of filling coils for intracranial aneurysm embolisation

Background In endovascular embolisation for an intracranial aneurysm, after framing coil deployment, soft coils (often called filling coils) are usually selected to fill inside the cage of previous coils. Various kinds of filling coils are available, although each coil has its own characteristics. Understanding their differences to ensure proper coil selection is important to achieve successful embolisation. The purpose of this study was to investigate the characteristics of various filling coils. Materials and methods The authors developed a radiolucent coil to evaluate the performance of coils under conditions simulating the course of embolisation. Experimental embolisation was performed by using a silicone aneurysm filled with radiolucent coils. Indices including area, circularity, centroid position and coefficient of variation were investigated by analysing the figures of the filling coils after being inserted into the radiolucent coil under fluoroscopy. Results The characteristics of each coil depended on the coil design. The helical coil had the highest circularity and centroid position scores and lowest area score. Therefore, it tended to develop a compacted mass. The low shape-memory coil had the lowest circularity, second-highest centroid position and highest coefficient of variation scores. Therefore, it tended to develop irregularly shaped distribution with low reproducibility. Complex coils generally had higher area and circularity scores. Therefore, they tended to provide a balanced distribution with relatively expanded mass and less small compartmentation. Conclusions The evaluated characteristics of various filling coils should be useful for appropriate selection of filling coils.

Coiling of a Ruptured Large Internal Carotid Artery Aneurysm via Extracranial-Intracranial Saphenous Vein Bypass Graft Just After Proximal Ligation of the Internal Carotid Artery

BACKGROUND Combined direct and endovascular surgery has been performed to treat large to giant internal carotid artery (ICA) aneurysms. This report describes successful treatment of a large ICA aneurysm by coiling of the aneurysm via an extracranial-intracranial saphenous vein (SV) graft just after bypass and ICA proximal ligation. CASE DESCRIPTION A 66-year-old woman presented with a left ICA supraclinoid aneurysm with progressive visual field defect and impaired visual acuity in the left eye. While waiting for scheduled surgery, she experienced a subarachnoid hemorrhage. An extracranial-intracranial high-flow bypass using an SV graft and proximal ligation of the ICA were performed. Coiling of the aneurysm was immediately performed successfully via the SV bypass graft. The patient experienced no new neurologic deficit after this treatment. Follow-up radiologic evaluations using magnetic resonance imaging and magnetic resonance angiography revealed complete aneurysm occlusion. CONCLUSIONS Aneurysm coiling via an extracranial-intracranial SV bypass graft could offer an alternative when an antegrade access route to the ICA is not used because of prior parent artery ligation.