Yasuhiro Sanada

Optimal reconstruction of the bony defect after frontotemporal craniotomy with hydroxyapatite cement

Numerous procedures have been reported for reconstruction of the bony defect around the sphenoid ridge after a frontotemporal craniotomy. However, it is still often difficult to restore the defect because of the complex curvature. Here we describe a simple cranial reconstruction method using hydroxyapatite cement and gelatin sponges. This procedure has been used on six patients, and satisfactory reconstruction was confirmed in all with postoperative three-dimensional CT scans. Using this technique, the bony defect was completely reconstructed with an appropriate thickness and curvature.

Safe and accurate sylvian dissection with the use of indocyanine green videoangiography

Background: Sylvian dissection is an essential microneurosurgical skill for neurosurgeons. The safe and accurate opening of the sylvian fissure is desirable for a good prognosis. Methods: The aim of this report is to demonstrate the use of indocyanine green (ICG) videoangiography to recognize the superficial sylvian vein (SSV) and thus enable a wide opening of the sylvian fissure, especially in patients with subarachnoid hemorrhage (SAH). Results: The small tributary flowing into the SSV was distinguishable from a passing one, which deeply entered the insula. In addition, an entering point of a tributary to the SSV, which ran perpendicular to the insula, was occasionally determined. SSV, which was barely discernable in a reddish SAH involving the sylvian fissure, was clearly demarcated using ICG videoangiography. Two representative cases of sylvian dissection are herein presented. Conclusion: The performance of ICG videoangiography before sylvian dissection is a simple and useful method for identifying a vital approach route for safe and accurate sylvian dissection, and it reduces the risk of causing any accidental injury to the veins in the sylvian fissure.

A case of angiographically occult, distal small anterior inferior cerebellar artery aneurysm.

Background: A small aneurysm at an unusual location, such as a distal anterior inferior cerebellar artery (AICA) aneurysm, may conceal as a computed tomography angiography (CTA) and digital subtraction angiography (DSA)-occult aneurysm. Case Description: We herein present the case of a patient suffering from a subarachnoid hemorrhage (SAH) with two aneurysms in which the AICA aneurysm was negative by CTA and DSA. CTA demonstrated a right anterior choroidal artery aneurysm, which was revealed to be an unruptured aneurysm after surgical exploration. A small distal AICA aneurysm was detected by 3D rotational angiography (3DRA). The patient fully recovered except for left-side hearing loss four months after the second operation. Conclusion: We recommend a meticulous diagnosis by 3DRA in patients with SAH in which the distribution is not coincident with a typical aneurysmal location.

Surgical accessibility of the distal internal carotid artery on carotid endarterectomy evaluated using magnetic resonance angiography.

BACKGROUND Magnetic resonance angiography (MRA) is helpful for preoperatively evaluating the degree of carotid stenosis, although it is not always useful for assessing surgical accessibility to the distal internal carotid artery (ICA) due to the lack of osteological information. OBJECTIVE To demonstrate a method for evaluating the accessible distal portion of the ICA for carotid endarterectomy (CEA) using MRA. METHODS As an indicator of the upper limit of the operating field, a line drawn from the C1 transverse process to the hyoid bone (C1-H line) was defined. The cross-point between the C1-H line and distal ICA was delineated on 3-dimensional (3-D) MRA and 3-D tomography angiography (CTA). The distance between the carotid bifurcation and C1-H line was measured in 11 patients. The exposed distal ICA was compared with the extent of intraoperative ICA exposure. RESULTS The mean vertical distance (27.5 mm) from the carotid bifurcation to the C1-H line measured using 3-D MRA was almost the same as the distance (28 mm) evaluated on 3-D CTA. The discrepancy in distance between the 2 modalities was 1.9 ± 1.7 mm. Furthermore, the point of the ICA across the C1-H line created on 3-D MRA was in accordance with the intraoperative measurement (28.7 mm) of the exposed ICA. CONCLUSION The C1-H line measured on 3-D MRA is a simple and useful indicator of the distal point of the accessible ICA during CEA, especially in patients with renal dysfunction and allergies to contrast medium.

Long-term follow-up for ossification of autologous bone plug and skin sinking after periosteum-preserved burr hole surgery

Background: The demand of a burr hole surgery for chronic subdural hematoma (CSDH) is increasing in the global aging society. Burr hole-derived autologous bone dusts are not associated with extra costs compared with other commonly used synthetic materials. In addition, postoperative calvarium ossification requires periosteum-mediated blood supply, which is lacking after using avascular synthetic materials. Based on these findings, we hypothesized that the combination of the bone plugs and the preserved periosteum during burr hole surgeries for CSDH would induce efficient calvarium ossification. Methods: We evaluated the long-term effects of bone plugs on the degree of ossification and cosmetic appearance of the skin covering the burr hole sites. We included 8 patients (9 burr holes) who received the autologous bone dust derived from burr holes. As the control group, 9 burr holes that did not receive any burr hole plugs were retrospectively selected. These burr holes were evaluated by computed tomography (CT) scan for the calvarium defect ratios, CT value-based ossification, and the degree of skin sinking. Results: Ossification was observed in all the bone plugs by the bone density CT scans; they maintained their volume at 12 months after the surgeries. The calvarium defect ratios (volume ratios of the unossified parts in the burr holes) gradually increased during the first 6 months and reached 0.44 at 12 months. The mean CT values also increased from 527 HU to 750 HU for the first 6 months and reached 905 HU at 12 months. The degrees of skin sinking at the burr hole sites with the bone plugs were 1.24 mm whereas those without the bone plugs were 2.69 mm (P = 0.004). Conclusion: Application of burr hole-derived autologous bone dust is associated with better ossification and objective cosmetic result following burr hole surgery after CSDH.

The use of fibrin and gelatin fixation to repair a kinked internal carotid artery in carotid endarterectomy.

Background: The kinking of the internal carotid artery (ICA) after final closure in carotid endarterectomy (CEA) is thought to be uncommon. When it occurs, it is mandatory to reconstruct ICA to preserve normal blood flow. We herein present a case in which a fixation technique was applied to repair an ICA that became kinked during CEA. Case Description: A 68-year-old man presented with cerebral infarction due to an artery-to-artery embolism from the right cervical ICA stenosis. CEA was performed 12 days after admission. After final closure, a distal portion of ICA was found to have been kinked following plaque resection in CEA procedure. Fixation with fibrin glue and gelatin was used to reinforce the arterial wall and repair the kink. Postoperative magnetic resonance angiography demonstrated the release of the kink in ICA. Conclusion: Fixation with fibrin and gelatin is a salvage armamentarium that can be considered in CEA for the repair of kinked or tortuous ICA.

Zigzag Skin Incision Effectively Camouflages the Scar and Alopecia for Moyamoya Disease: Technical Note

Moyamoya disease is commonly diagnosed in children, and requires various vascular reconstruction to improve symptoms. Therefore, scar widening and hair loss after craniotomy, which sometimes occurs in this disease, are serious problems for patients. A variety of plastic surgical techniques in scalp have been reported to minimize the scar widening and hair loss. However, any neurosurgical reports describing this purpose have never been published for moyamoya disease. The objective of this study was to investigate whether these plastic surgical techniques could be applied to bypass surgery without any compromise of vascular reconstruction for moyamoya disease. We performed direct and indirect vascular reconstruction in six hemispheres of moyamoya disease patients not only in the middle cerebral artery territory but also in the anterior cerebral artery territory. The scalp incision was designed not parallel to the hair stream, and the bevelled incision was conducted not to jeopardize the hair follicles. The scar and hair loss were effectively camouflaged throughout the postoperative period in all cases. This study demonstrates that our design of scalp incision achieve effective vascular reconstruction and obscure the scar and hair loss.