Faculty Profiles - Tanaka Shota

Factors associated with endocrine deficits after stereotactic radiosurgery of pituitary adenomas. Reviewed International journal

James L Leenstra, Shota Tanaka, Robert W Kline, Paul D Brown, Michael J Link, Todd B Nippoldt, William F Young Jr, Bruce E Pollock

Neurosurgery 67 ( 1 ) 27 - 32 2010.7

Language：English Publishing type：Research paper (scientific journal) Publisher：LIPPINCOTT WILLIAMS & WILKINS

OBJECTIVE: To analyze the factors associated with anterior pituitary deficits after pituitary adenoma stereotactic radiosurgery (SRS). METHODS: The tumor, pituitary stalk, and pituitary gland were segmented on the dose plans of 82 patients (secreting tumors, n = 53; nonsecreting tumors, n=29) for dose-volume analysis. No patient had undergone prior radiation therapy and all patients had at least 12 months of endocrinological follow-up (median, 63 months; mean, 69 months; range, 13-134). RESULTS: Thirty-four patients (41%) developed new anterior pituitary deficits at a median of 32 months (range, 2-118) after SRS. The risk of developing new anterior pituitary deficits was 16% and 45% at 2 and 5 years, respectively. Multivariate analysis of the entire group showed that poor visualization of the pituitary gland (hazard ratio [HR]=2.63, 95% confidence interval [CI]=1.10-6.25, P=.03) was associated with a higher rate of new anterior pituitary deficits. Dosimetric analysis of 60 patients whose pituitary gland could be clearly identified showed that increasing mean pituitary gland radiation dose correlated with new anterior pituitary deficits (HR=1.11, 95% CI=1.02-1.20, P=.02). New anterior pituitary deficits stratified by mean pituitary gland radiation dose: <or=7.5 Gy, 0% (0/7); 7.6 to 13.2 Gy, 29% (7/24); 13.3 to 19.1 Gy, 39% (9/23); >19.1 Gy, 83% (5/6). CONCLUSION: New endocrine deficits after pituitary adenoma radiosurgery were correlated with increasing radiation dose to the pituitary gland. Methods that limit the radiation dose to the pituitary gland during SRS may increase the probability of preserving pituitary function.

DOI： 10.1227/01.NEU.0000370978.31405.A9

Hip- and pelvic-related intraneural ganglia. Reviewed International journal

Robert J Spinner, Marie-Noëlle Hébert-Blouin, Shota Tanaka, Kimberly K Amrami, Karin R Swartz, Dominic B Fee, Makoto Sugita

Journal of neurosurgery 112 ( 6 ) 1353 - 6 2010.6

Adherence of intraneural ganglia of the upper extremity to the principles of the unifying articular (synovial) theory. Reviewed International journal

Huan Wang, Robert Q Terrill, Shota Tanaka, Kimberly K Amrami, Robert J Spinner

Neurosurgical focus 26 ( 2 ) E10 2009.2

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER ASSOC NEUROLOGICAL SURGEONS

OBJECT: Intraneural ganglia are nonneoplastic mucinous cysts contained within the epineurium of peripheral nerves. Their pathogenesis has been controversial. Historically, the majority of authors have favored de novo formation (degenerative theory). Because of their rarity, intraneural ganglia affecting the upper limb have been misunderstood. This study was designed to critically analyze the literature and to test the hypothesis that intraneural ganglia of the upper limb act analogously to those in the lower limb, being derived from an articular source (synovial theory). METHODS: Two patients with digital intraneural cysts were included in the study. An extensive literature review of intraneural ganglia of the upper limb was undertaken to provide the historical basis for the study. RESULTS: In both cases, the digital intraneural ganglia were demonstrated to have joint connections; the one patient in whom an articular branch was not appreciated initially had evidence on postoperative MR images of persistence of intraneural cyst after simple decompression was performed. Eighty-six cases of intraneural lesions were identified in varied locations of the upper limb: the most common sites were the ulnar nerve at the elbow and wrist, occurring 38 and 22 times, respectively. Joint connections were present in only 20% of the cases published by other groups. CONCLUSIONS: The authors believe that the fundamental principles of the unifying articular (synovial) theory (that is, articular branch connections, cyst fluid following a path of least resistance, and the role of pressure fluxes) previously described to explain intraneural ganglia in the lower limb apply to those cases in the upper limb. In their opinion, the joint connection is often not identified because of the cysts' rarity, radiologists' and surgeons' inexperience, and the difficulty visualizing and demonstrating it because of the small size of the cysts. Furthermore, they believe that recurrence (subclinical or clinical) is not only underreported but also predictable after simple decompression that fails to address the articular branch. In contrast, intraneural recurrence can be eliminated with disconnection of the articular branch.

DOI： 10.3171/FOC.2009.26.2.E10

Direct and primary carotid endarterectomy for common carotid artery occlusion. Report of 2 cases. Reviewed International journal

Tomohiro Inoue, Kazuo Tsutsumi, Shinobu Adachi, Shota Tanaka, Naoto Kunii, Masahiro Indo

Surgical neurology 69 ( 6 ) 620 - 6 2008.6

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE INC

BACKGROUND: Cerebral ischemia associated with chronic CCA occlusion is a rare condition and raises strategic dilemma when the revascularization is needed. METHODS: Two patients with CCA occlusion presented with ischemic symptom associated with the affected side. Both patients underwent vascular reconstruction by direct carotid endarterectomy to achieve primary restoration of CCA to ICA flow. RESULTS: Successful reopening of the vessels was obtained in both patients without the evidence of postsurgical ischemic event. Follow-up MRA was obtained at later than 6 months after surgery, which demonstrated patent CCA-ICA in both patients. CONCLUSIONS: Direct carotid endarterectomy of the occluded CCA can be safely performed if the preoperative angiography suggest still patent vessels distal to carotid bifurcation and the substantial "back flow" is obtained from ICA during arteriotomy.

DOI： 10.1016/j.surneu.2007.01.034

Clipping and superficial temporal artery-M2 bypass for unruptured anterior communicating artery aneurysm associated with atherosclerotic internal carotid artery occlusion: report of 2 cases. Reviewed International journal

Tomohiro Inoue, Kazuo Tsutsumi, Shinobu Adachi, Shota Tanaka, Kuniaki Saito, Naoto Kunii

Surgical neurology 68 ( 2 ) 226 - 31 2007.8

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE INC

BACKGROUND: The management of the unruptured AcomA aneurysm associated with atherosclerotic occlusion of the unilateral internal carotid artery (ICA) raises several strategic dilemmas. METHODS: Two such patients with unruptured aneurysm on the AcomA, which supply cross-flow toward the hemisphere with ICA occlusion, are presented. RESULTS: Both patients were treated with STA-M2 bypass followed by clipping of the unruptured AcomA aneurysm in 1 stage through the transsylvian route. Both patients were doing well without neurological deficit nor cognitive impairment at 1 year follow-up. CONCLUSIONS: In the surgical treatment of unruptured AcomA aneurysm with atherosclerotic ICA occlusion, preceding bypass would be ideal in case of intraoperative rupture as well as to reduce perioperative ischemia if the bypass procedure itself could be performed with minimal risk. Enough and atraumatic exposure of the sylvian fissure contributed to reduce brain retraction during the clipping of AcomA aneurysm and, in addition, to ease the STA-M2 bypass.

DOI： 10.1016/j.surneu.2006.10.031

Recurrent subarachnoid hemorrhage after complete occlusion of a ruptured small-necked, small vertebral artery-posterior inferior cerebellar artery aneurysm. Case illustration. Reviewed International journal

Tomohiro Inoue, Kazuo Tsutsumi, Kyoko Yako, Shota Tanaka

Journal of neurosurgery 106 ( 3 ) 514 - 514 2007.3

Training of A3-A3 side-to-side anastomosis in a deep corridor using a box with 6.5-cm depth: technical note. Reviewed International journal

Tomohiro Inoue, Kazuo Tsutsumi, Kuniaki Saito, Shinobu Adachi, Shota Tanaka, Naoto Kunii

Surgical neurology 66 ( 6 ) 638 - 41 2006.12

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE INC

BACKGROUND: Cerebral revascularization in the deep surgical field is technically challenging. Especially, side-to-side anastomosis like A3-A3 could be technically more difficult compared with end-to-side anastomosis. To improve surgeon's dexterity and maneuverability in the deep surgical field, the authors developed an easily accessible and well-simulating training system using prosthetic tubes and a box. METHODS: Two prosthetic tubes (silicon tube, 1.2 mm in diameter) are mounted in parallel on the bottom of 6.5-cm-deep emptied 'tissue paper box.' The orifice of the box is restricted to 2 x 2 cm to simulate a deep and narrow surgical corridor. Using bayonet-shaped micro needle holder and forceps, the side-to-side anastomosis of the tubes is performed with 10-0 nylon under operative microscope. RESULTS: Prosthetic tubes well simulated real A3-A3 anastomosis. From the standpoint of technical difficulty, this training system needed slightly higher level of dexterity compared with real A3-A3 anastomosis because of narrower and deeper surgical corridor, and the wall of prosthetic tube was slightly thicker and more inflexible. After this training, the surgical technique in real A3-A3 anastomosis was improved. CONCLUSIONS: This training system worked well to ease the transition from anastomosis in shallow surgical field to deep and narrow surgical field. The prosthetic tube we used approximates real A3 relatively well, and the ease in setting up this system enabled repeated practice, which resulted in steep learning curve of the technique.

DOI： 10.1016/j.surneu.2006.03.035

Incidence of ischemic lesions by diffusion-weighted imaging after carotid endarterectomy with routine shunt usage. Reviewed

Tomohiro Inoue, Kazuo Tsutsumi, Keiitirou Maeda, Shinobu Adachi, Shota Tanaka, Kyoko Yako, Kuniaki Saito, Naoto Kunii

Neurologia medico-chirurgica 46 ( 11 ) 529 - 33 2006.11

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN NEUROSURGICAL SOC

Temporary intraluminal shunt was used during 72 consecutive carotid endarterectomies (CEAs) in 61 patients (bilateral CEA in 11 patients) during October 2001 and September 2005. The medical records of these patients were retrospectively reviewed. All procedures were performed with routine shunt insertion without monitoring such as electroencephalography. Pre- and postoperative diffusion-weighted magnetic resonance (MR) imaging was used to detect ischemic complications. Postoperative angiography was performed in 70 cases to detect abnormalities such as major stenosis or dissection of the distal end. Symptomatic ischemic complication occurred in one patient at 1 month. Postoperative diffusion-weighted MR imaging detected new hyperintense lesions in three patients including the symptomatic patient. Postoperative angiography confirmed that the distal end was satisfactory in all cases. The incidence of ischemic lesions of embolic origin after CEA with routine shunt usage is acceptably low if the procedure of shunt device insertion and removal is meticulously conducted.

Effectiveness of suturing training with 10-0 nylon under fixed and maximum magnification (x 20) using desk type microscope. Reviewed International journal

Tomohiro Inoue, Kazuo Tsutsumi, Shinobu Adachi, Shota Tanaka, Kuniaki Saito, Naoto Kunii

Surgical neurology 66 ( 2 ) 183 - 7 2006.8

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE INC

BACKGROUND: Microvascular anastomosis using 10-0 nylon needs a higher level of technical dexterity compared with routine neurosurgical maneuvers. Although this technique remains an important part of treating complex intracranial aneurysms or cerebrovascular disease, the surgeon's clinical experience in using this technique is not so common. METHODS: To improve dexterity and maneuverability in the limited clinical case volume, we developed an easily accessible training system, using commercially available desk type microscope and simply suturing neighboring fibers of the gauze with 10-0 nylon under fixed and highest (x 20) magnification. RESULT: This training system is somewhat of a drawback compared to the simulation of a real clinical setting. However, because of the extremely easy availability and accessibility of the dark type microscope repeated training and the accumulation of more than 10000 stitches, on average, was accomplished. This resulted in a steep learning curve of the technique. CONCLUSION: For residency and post-residency year young neurosurgeons, who need to brush up their skills due to lower surgical case volume compared with what senior neurosurgeons have experienced this easily available training would contribute to establishing daily and long-lasting microsurgical practice.

DOI： 10.1016/j.surneu.2005.11.064

CEA for Near Occlusion : Technical Note

KUNII Naoto, TSUTSUMI Kazuo, INOUE Tomohiro, ADACHI Shinobu, TANAKA Shota, SAITO Kuniaki, Naoto KUNII, Kazuo TSUTSUMI, Tomohiro INOUE, Shinobu ADACHI, Shota TANAKA, Kuniaki SAITO, Department of Neurosurgery Showa General Hospital, Department of Neurosurgery Showa General Hospital, Department of Neurosurgery Showa General Hospital, Department of Neurosurgery Showa General Hospital, Department of Neurosurgery Showa General Hospital, Department of Neurosurgery Showa General Hospital

Nosotchu no Geka Kenkyukai koenshu 34 ( 1 ) 27 - 31 2006.1

Language：Japanese Publisher：The Japanese Society on Surgery for Cerebral Stroke

The effectiveness of CEA in preventing further stroke of the patient with high grade carotid stenosis is well known. However, controversy still exists as for the choice of CEA or low flow bypass in the cases of near occlusion because of the uncertainty of the patency of distal ICA as well as the risk for postoperative hyperperfusion.<br> We experienced 7 consecutive cases of near occlusion between May and November 2004 and performed CEA. In all cases, the flexible shunt (Furui shunt) was employed to reduce the risk of hemodynamic ischemia during clamping. To prevent distal embolism during distal shunt tube insertion, great care was taken to secure the "true distal lumen" high enough above the stenotic site. If necessary, arteriotomy was added on the distal wall and then connected toward the proximal. The use of a shunt tube was helpful in gaining a fine view of the distal end during endarterectomy because it held the collapsed lumen round open. <br> There were no ischemic complications. Good patencies were demonstrated by postoperative DSAs in all cases.<br> In our experiences, CEA could be safely performed as long as the angiography shows patent ICA distal to stenotic site even in delayed fashion. <br>

DOI： 10.2335/scs.34.27

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Other Link： https://jlc.jst.go.jp/DN/JALC/00273987947?from=CiNii

Endoscopic evacuation of hypertensive intracerebral hemorrhage: The importance of hemostasis in ultra-early surgery Reviewed

Tetsuhiro Nishihara, Kazuya Nagata, Junichi Takeda, Shota Tanaka, Yasutaka Suzuki, Masafumi Izumi, Yubuhito Mochizuki, Atsuya Akabane, Chikayuki Ochiai

Japanese Journal of Neurosurgery 14 ( 6 ) 401 - 406 2005

Language：Japanese Publishing type：Research paper (international conference proceedings) Publisher：Japanese Congress of Neurological Surgeons

Ultra-early surgical treatments are expected to be established, in which the associated brain injury is minimized and a maximal volume of hematoma is removed shortly after onset with secure hemostasis. We developed a transparent guiding sheath and other surgical instruments for endoscopic surgery, and we established a novel surgical procedure in the ultra-early stage using those instruments. This procedure has the following characteristics: (1) the capability of burr hole opening under local anesthesia, (2) a transparent sheath improves the surgical field visualization of the parenchyma and the hematoma, (3) free-hand surgery without fixing an endoscope and a sheath to a frame facilitates three-dimensional operation, (4) the capability of secure hemostasis by electric coagulation (When bleeding from a perforating artery occurs, a suction tube is placed at the bleeding point and hemostasis is achieved by electric coagulation), (5) easy preparation of relatively simple surgical instruments. We have performed this procedure on 85 patients with intracerebral or intraventricular hemorrhage. Among these 85 patients, 24 patients received our treatment in the ultra-early stage, or within 3 hours after onset. The mean duration of surgery was 63 minutes, the mean hematoma reduction rate was 96%, and no perioperative hemorrhage with deterioration of symptoms and/or signs occurred. Thus, we believe that endoscopic hematoma evacuation with our surgical procedure is a promising ultra-early-stage treatment for intracerebral hemorrhage, and that it may improve the long-term prognosis of patents with intracerebral hemorrhage.

DOI： 10.7887/jcns.14.401

Scopus

Newly developed endoscopic instruments for the removal of intracerebral hematoma. Reviewed International journal

Tetsuhiro Nishihara, Kazuya Nagata, Shota Tanaka, Yasutaka Suzuki, Masafumi Izumi, Yubuhito Mochizuki, Atsuya Akabane, Chikayuki Ochiai

Neurocritical care 2 ( 1 ) 67 - 74 2005

Language：English Publishing type：Research paper (scientific journal) Publisher：HUMANA PRESS INC

Ultra-early surgical treatment in which associated brain injury is minimized and maximal volume of hematoma is removed shortly after onset with secure hemostasis is expected to be established. We developed a transparent guiding sheath and other surgical instruments for endoscopic surgery and established a novel, ultra-early stage surgical procedure using those instruments. This procedure has the following characteristics: (a) burr hole opening under local anesthesia is possible; (b) a transparent sheath improves the visualization of the surgical field in the parenchyma and the hematoma; (c) free-hand surgery without fixing an endoscope and a sheath to a frame facilitates three-dimensional operation; (d) secure hemostasis by electric coagulation is possible; (e) relatively simple surgical instruments are easy to prepare. We have performed this procedure in 82 patients with intracerebral or intraventricular hemorrhage (44 with putaminal hemorrhage, 12 with thalamic hemorrhage, 8 with subcortical hemorrhage, 8 with cerebellar hemorrhage, 10 with intraventricular hemorrhage). Twenty-four of those patients received our treatment in the ultra-early stage (within 3 hours after onset). The mean duration of surgery was 63 minutes, the mean hematoma reduction rate was 96%, and no peri-operative hemorrhage with deterioration of symptoms and/or signs occurred. Therefore, we believe that endoscopic hematoma evacuation with our surgical procedure is a promising ultra-early stage treatment for intracerebral hemorrhage and that it may improve the long-term prognosis in patents with intracerebral hemorrhage.

DOI： 10.1385/NCC:2:1:067