Yosuke Hara

The concept and feasibility of EXPRT: Intelligent armrest using robotics technology

BACKGROUND Continuous precise motions are required in microneurosurgery to provide high-quality surgical results. Stabilizing the surgeons arm and reducing fatigue during surgery are expected to improve the precision of microsurgical procedures. We have developed an intelligent armrest, EXPERT, that follows the surgeons hand and fixes at an adequate position automatically using robotics technology. OBJECTIVE To understand the feasibility of EXPERT by using the system in laboratory experiments and clinical situations. METHODS EXPERT has an arm holder and acts as a passive controlled robot with 5 degrees of freedom. The system has 3 modes: transfer, arm-holding, and arm-free mode, which are selected automatically. In the transfer mode, the arm holder follows the surgeons arm. In the arm-holding mode, EXPERT supports the surgeons arm weight by fixing the arm holder. The surgeon can move his/her arm away from the arm holder in the arm-free mode. The surgeon can change the position of armrest while looking through the microscope and can continue the microsurgical procedure while holding surgical instruments. Since 2010, EXPERT has been applied in 13 surgeries. RESULTS The EXPERT system decreased surgeon fatigue and reduced difficulty in performing surgical procedures. The EXPERT system markedly reduced surgeon hand tremor. There were no complications related to the use of this system. CONCLUSION EXPERT is a useful tool for holding the surgeons arm comfortably and following the surgeons arm automatically.

Monitoring serum IL-18 levels is useful for treatment of a patient with systemic juvenile idiopathic arthritis complicated by macrophage activation syndrome

Systemic juvenile idiopathic arthritis (sJIA) is a systemic inflammatory disease characterized by arthritis, spiking fever and a skin rash that is frequently complicated by macrophage activation syndrome (MAS), a life-threatening disorder. We report a 22-month-old girl with sJIA who developed severe MAS but was successfully treated with corticosteroids, cyclosporin A, and non-steroidal anti-inflammatory drugs by monitoring serum IL-18 levels. IL-18 is an extremely useful cytokine for monitoring the activity of sJIA and MAS, and serum IL-18 can be used as an indicator for the effectiveness of treatment and the decision to discontinue therapy.

Relationship Between Muscle Dissection Method and Postoperative Muscle Atrophy in the Lateral Suboccipital Approach to Vestibular Schwannoma Surgery.

BACKGROUND Various techniques are available for occipital skull exposure with muscle dissection, as well as different types of skin incisions in the lateral suboccipital approach to vestibular schwannoma (VS) surgery. The skin incisions are generally classified as S-shaped, J-shaped, or C-shaped. In each method, the technique used for muscle dissection differs in terms of cut, single layer, and multiple layers. This study was performed to identify the relationships among muscle dissection method, skin incision type, and muscle atrophy in the lateral suboccipital approach to surgery for VS. METHODS Between 2002 and 2011, we performed surgical resection in 53 patients with VS at Shinshu University Hospital. Of these 53 patients, 35 with radiographic annual follow-up for >3 years after surgery were evaluated retrospectively. These patients included 14 who underwent an S-shaped incision, 6 with a J-shaped incision, and 15 with a C-shaped incision. Bilateral areas of the skin and occipital muscles were measured, and rates of atrophy were calculated and compared among the 3 methods. RESULTS Postoperative muscle atrophy was significantly advanced in the second postoperative year, but did not tend to develop further after the third year. The postoperative muscle atrophy ratio was significantly lower in the C-shaped incision group (mean ± SD, 4.0% ± 6.9%) compared with the S-shaped (17.1% ± 9.8%) and J-shaped (17.6% ± 10.0%) incision groups within 2 years after surgery (P < 0.05). CONCLUSIONS The C-shaped skin incision with multilayer muscle dissection was associated with significantly reduced postoperative muscle atrophy compared with the other methods.

An armrest is effective for reducing hand tremble in neurosurgeons.

Experienced neurosurgeons reduce hand tremble by placing their hand beside the operative field when performing microneurosurgery conventionally. Another solution to reduce hand tremble is an armrest. However, the reduction of hand tremble by using an armrest or finger-placing technique has not been rigorously measured in microneurosurgery. This study was performed to provide a quantitative assessment of the efficacy of an armrest to reduce hand tremble in comparison with the finger-placing technique. Hand tremble was evaluated in 11 board-certified neurosurgeons in a simulated microneurosurgery. The loci of surgical forceps handled by neurosurgeons were measured by a three-dimensional optical coordinate measuring machine. A static task was performed under four conditions: with/without the finger-placing technique and/or an armrest. The radius of an imaginative sphere including 95% of each locus was calculated and reviewed according to the four conditions. Hand tremble was significantly larger when the finger-placing technique was not implemented compared to when the technique was used (P < 0.05). The armrest also reduced hand tremble (P < 0.05) similar to the finger-placing technique. Non-inferiority was retained between the finger-placing technique and the armrest. Concomitant use of the armrest and the finger-placing technique did not interfere with the efficacy of the technique to reduce neurosurgeon’s hand tremble. The finger-placing technique was confirmed to reduce hand tremble. Resting the neurosurgeon’s forearm on an armrest also reduced the hand tremble. An armrest is a device that reduces hand tremble in neurosurgeons like the finger-placing technique.

Gliosarcoma arising from a fibrillary astrocytoma

We report a 67-year-old woman who was diagnosed with a gliosarcoma at a second operation after diagnosis of a fibrillary astrocytoma 5 months previously. Initially, she underwent a CT-guided stereotactic biopsy. Histological examination showed fibrillary astrocytoma (World Health Organization [WHO] grade II). Loss of heterozygosity (LOH) on 1p, 10q, and 19q was not detected. She received chemotherapy, but no radiotherapy. Five months after the biopsy, MRI revealed rapid tumor growth. Tissue obtained from partial removal of the tumor revealed gliosarcoma (WHO grade IV), and LOH on 10q and 19q was detected. The history, histopathology, and genetic alterations of this patient are discussed.

Suboccipital Approach for Primitive Trigeminal Artery Obliteration Associated with Cavernous Aneurysm

OBJECTIVE A 63-year-old woman presented with diplopia resulting from abducens paralysis. Examination revealed a giant cavernous aneurysm supplied by the internal carotid artery (ICA) and primitive trigeminal artery (PTA) via the vertebrobasilar system. METHODS After evaluation of balloon test occlusion (BTO) at the distal side of the PTA origin, the aneurysm was treated with PTA obliteration through the suboccipital route in the lateral position followed by cervical carotid ligation with superficial temporal artery-to-middle cerebral artery anastomosis in the supine position. RESULTS The aneurysm showed marked shrinkage after the surgery. CONCLUSION PTA obliteration through the retrosigmoid opening is a therapeutic surgical option in a patient with a cavernous aneurysm supplied by the PTA.

Staple electrodes: an innovative alternative for intraoperative electrophysiological monitoring.

Intraoperative electrophysiological monitoring is essential for minimally invasive neurosurgery. The authors developed an innovative recording method using a staple electrode, consisting of a surgical skin staple and an integrated circuit (IC) test clip with a cable. The staple is put on the patients skin after the induction of general anesthesia. After head fixation, the IC test clip is simply hooked to the staple. The authors used this method for recording in 158 consecutive cases. It took only a few minutes to set up 4-18 staple electrodes in each case. None of the staple electrodes became disconnected unintentionally, and the initial impedance was kept throughout the procedures. The authors conclude that the staple electrode is superior to conventional disc or needle electrodes in speed of setup, electrical stability, and cost-effectiveness and recommend its routine use for intraoperative electrophysiological monitoring.

Real-Time Navigation-Guided Drilling Technique for Skull Base Surgery in the Middle and Posterior Fossae

Objective The usefulness of the bony surface registration method for navigation system image‐guided surgery in the lateral or prone position has been reported. This study was performed to evaluate the efficacy of our new real‐time navigation‐guided drilling technique with bony surface registration for skull base surgery in the middle and posterior fossae. Methods The study included 29 surgeries for skull base tumors that required drilling of the petrous bone between January 2015 and December 2017 in Shinshu University Hospital. A navigation system was used for drilling of the petrous bone as follows: (1) some labyrinthine structures were marked by color in the source image and superimposed on the navigation image on the workstation preoperatively; (2) bony surface registration was performed with a three‐dimensional (3D) skull reconstruction model in the operating room; (3) the petrous bone was drilled under navigation guidance with real‐time view‐through confirmation of 3D color‐marked labyrinthine structures with observation under a microscopic operative view. Results Real‐time identification of some structures in the petrous bone was performed, and adequate and precise drilling of the petrous bone was achieved without the risk of labyrinthine perforation or stress. Using this method, surgeons do not need to alternate their gaze between the surgical field and the navigation screen. Conclusions Due to the development of bony surface registration, this new technique is useful for drilling petrous bone in the middle and posterior fossa skull base surgeries.

An infant case of diffuse cerebrospinal lesions and cardiomyopathy caused by a BOLA3 mutation

INTRODUCTION Mitochondrial dysfunction results in a wide range of organ disorders through diverse genetic abnormalities. We herein present the detailed clinical course of an infant admitted for extensive, rapidly progressing white matter lesions and hypertrophic cardiomyopathy due to a BOLA3 gene mutation. CASE A 6-month-old girl with no remarkable family or past medical history until 1 month prior presented with developmental regression and feeding impairment. Ultrasound cardiography and brain magnetic resonance imaging (MRI) respectively disclosed the presence of hypertrophic cardiomyopathy and symmetrical deep white matter lesions. She was transferred to our hospital at age 6 months. High lactate levels in her cerebrospinal fluid suggested mitochondrial dysfunction. Despite vitamin supplementation therapy followed by a ketogenic diet, the patient began exhibiting clusters of myoclonic seizures and respiratory failure. Brain and spinal cord MRI revealed rapid progression of the white matter lesions. She died at 10 months of age. Fibroblasts obtained pre-mortem displayed low mitochondrial respiratory chain complex I and II activity. A homozygous H96R (c. 287 A > G) mutation was identified in the BOLA3 gene. DISCUSSION No reported case of a homozygous BOLA3 gene mutation has survived past 1 year of life. BOLA3 appears to play a critical role in the electron transport system and production of iron-sulfur clusters that are related to lipid metabolism and enzyme biosynthesis.

A Rare Case of Pediatric Lumbar Spinal Ependymoma Mimicking Meningitis

Spontaneous acute subarachnoid hemorrhage (SAH) from lumbar ependymoma in children is rare. We report a case of a 14-year-old boy who developed sudden radicular low back pain while playing baseball. He was initially managed conservatively in a local hospital for suspected lumbar disc herniation, but he later developed meningeal symptoms and fever before being referred to our hospital. He underwent a diagnostic lumbar puncture in the emergency department; his cerebrospinal fluid suggested an SAH. Physical examination showed meningeal signs and cauda equina features. Cerebrospinal fluid analysis was negative for bacterial meningitis. Lumbar magnetic resonance imaging revealed a mass characterized as a hemorrhagic lesion. The patient had an emergent evacuation of the mass through the posterior approach. Postoperatively, his symptoms resolved completely. The histologic diagnosis was, surprisingly, an ependymoma (World Health Organization grade II). This case is particularly interesting because of its rarity in children, and its pattern of presentation. Although bacterial or viral meningitis is the most frequent cause of meningeal features in children, SAH from a hemorrhagic spinal tumor should be considered. Ultimately, a high index of suspicion is needed for prompt diagnosis.