Katsuo Shoin

Surgical indications and microsurgical anatomy of the transchoroidal fissure approach for lesions in and around the ambient cistern.

OBJECTIVE Opening the temporal part of the choroidal fissure (CF) makes it possible to expose the crural cistern, the ambient cistern, and the medial temporal lobe. We examined the microsurgical anatomy and the surgical indications for use of the trans-CF approach. METHODS The microsurgical anatomy encountered in the trans-CF approach for lesions in and around the ambient cistern was studied in three cadavers. On the basis of these cadaveric studies, the trans-CF approach was used during surgery in three live patients with such lesions. RESULTS The angiographic “plexal point,” which indicates the entrance of the anterior choroidal artery as it enters the temporal horn of the lateral ventricle, was thought to be a key anatomic landmark of the trans-CF approach. A cortical incision for entry into the temporal horn should be made in the inferior temporal gyrus to minimize the potential damage to the optic radiations and to the speech centers. After the CF is opened posteriorly to the plexal point between the tenia fimbria and the choroid plexus, the posterior cerebral artery (PCA) in the ambient cistern can be observed with minimal caudal retraction of the hippocampus. In this study, surgical procedures using the trans-CF approach were successfully performed on patients with high-positioned P2 aneurysms whose PCA ran close to the plexal point or higher, whose medial temporal arteriovenous malformations were fed mainly by the PCA, and whose tentorial hiatus meningiomas protruded into the temporal horn through the CF, with no resulting postoperative visual or memory disturbances. CONCLUSION The trans-CF approach is especially useful in surgery for lesions in and around the ambient cistern.

The change of plasma volume, central venous pressure and water balance of patients treated by haemodynamic therapy for vasospasm

The plasma volume, central venous pressure and water balance of 24 patients were measured around the 1st and 2nd week after early operations for ruptured aneurysms. All of the patients had been successfully treated by induced hypertension therapy for delayed vasospasm. Plasma volume was measured by the RI method using RISA. The average plasma volume of 16 patients was 58.3 +/- 6.2 ml/kg. This group had 200 ml of 25% albumin every day. It was 48.2 +/- 6.2 ml/kg for 8 patients without albumin administration. The average CVP was 11.3 +/- 2.2 cm on the albumin group. It was 5.3 +/- 1.5 cm on the non-albumin group. The value of plasma volume and CVP was statistically higher in the albumin group than in the non-albumin group. Water balance was positive in about half of the albumin group. It was negative in the non-albumin group. Three patients of the albumin group had pulmonary oedemas and one patient of the non-albumin group had congestive heart failure.

Treatment Result in the Initial Stage of Kanazawa Mobile Embolectomy Team for Acute Ischemic Stroke

Five recent multicenter randomized controlled trials (RCTs) have clearly shown the superiority of mechanical thrombectomy in large vessel occlusion acute ischemic stroke compared to systemic thrombolysis. Although 14 hospitals in Ishikawa prefecture have uninterrupted availability of systemic thrombolysis, mechanical thrombectomy is not available at all of these hospitals. Therefore, we established a Kanazawa mobile embolectomy team (KMET), which could travel to these hospitals and perform the acute reperfusion therapy. In this article, we report early treatment outcomes and validate the effectiveness of a network between affiliated hospitals and KMET. Between January 2014 and December 2015, 48 patients, aged 45–92 years (mean: 73.0 years), underwent acute reperfusion therapy provided by KMET in 10 affiliated hospitals of Kanazawa University Hospital. The pre-treatment NIHSS scores ranged from 5 to 39 (mean: 19.1). ASPECTS+W ranged from 1 to 11 (mean: 7.3). Successful revascularization, defined as thrombolysis in cerebral infarction (TICI) 2b or 3, was achieved in 38/48 cases (80%), and a good outcome, defined as modified Rankin Scale (mRS) score from 0 to 2 at 90 days after the treatment, was achieved in 24/48 cases (50%). There were two cases of intracranial bleeding (4%). Mean time from onset to recanalization was 297 min. These results, which are similar to those of five previous RCTs, suggest that a collaborative network between affiliated hospitals and KMET is effective for acute reperfusion therapy in local areas wherein experienced neuroendovascular specialists are insufficient.