Methods and Early Clinical Results of Percutaneous Lumbar Interbody Fusion

Shu Nakamura,Fjio Ito,Zenya Ito,Motohide Shibayama 대한척추신경외과학회 2020 Neurospine Vol.17 No.4

Objective: Percutaneous lumbar interbody fusion (PELIF) is a procedure that includes the use of new devices, which allow minimally invasive diskectomy under the percutaneous full-endoscopic guidance and safe percutaneous insertion of a standard-sized cage. This procedure can be applied to severe disk degeneration, spondylolisthesis, and all lumbar intervertebral levels including the L5–S1 level. We report the methods and the clinical outcomes of this procedure. Methods: Percutaneous diskectomy was performed with an outer sheath cutter and other devices. A cage was inserted with an L-shaped retract-slider. Hybrid facet screw fixation was performed for severe disk degeneration without spondylolisthesis. Conventional percutaneous pedicle screw fixation was performed for spondylolisthesis. The subjects consisted of 21 patients, who underwent PELIF and were followed up for 1 year or longer. Results: No complications related to cage insertion were detected. The mean visual analogue scale scores were improved from 6.1 to 1.9 for lower back pain in severe disc degeneration cases without spondylolisthesis, and from 7.6 to 1.0 for lower extremity symptoms in spondylolisthesis cases. Conclusion: The clinical outcomes were favorable. PELIF was found to be a minimally invasive method that did not compromise safety and efficiency. PELIF is a possible therapeutic option that should be considered for not only spondylolisthesis at various intervertebral levels but also for severe disk degeneration because of its minimal invasiveness.

Area of Ostectomy in Posterior Percutaneous Endoscopic Cervical Foraminotomy: Images and Mid-term Outcomes

Shu Nakamura,Mitsuto Taguchi 대한척추외과학회 2017 Asian Spine Journal Vol.11 No.6

Study Design: Retrospective. Purpose: To analyze whether the cross-sectional area of the intervertebral foramen at the outermost edge of the resection site is associated with postoperative outcomes and whether our fluoroscopic method for determining the resection area is appropriate. Overview of Literature: There is no consensus on the criteria for determining an optimal resection area to obtain sufficient decompression while maintaining intervertebral stability in posterior percutaneous endoscopic cervical foraminotomy. Previous reports have recommended a facet resection rate (FRR) of ≤50%. Intervertebral foramen stenosis often extends to the exit zone. The crosssectional area of the intervertebral foramen is occasionally small at the outermost edge of the resection site. No report has analyzed whether these aspects are associated with postoperative outcomes. Methods: Lateral margins of the resection area were set at lateral borders of the vertebral body on frontal fluoroscopic view. Because the percutaneous endoscope has a small diameter, surrounding structures can easily be identified using frontal view fluoroscopy to determine the resection area. FRRs were calculated from postoperative computed tomography images. The smallest crosssectional area of the intervertebral foramen around the lateral edge of the resection area (SALE) was measured and compared with clinical outcomes. Results: The mean FRR was 41.7% at C5–C6 and 48.9% at C6–C7. SALE was not correlated with clinical outcomes. Conclusions: Residual stenosis in the lateral portion of the intervertebral foramen is weakly associated with postoperative outcomes. Our process achieved adequate FRRs and favorable postoperative outcomes, suggesting that our criteria for determining the resection area are appropriate.

Use of an Internal Retractor for Percutaneous Full-Endoscopic Resection in Cervical Intervertebral Disc Herniation with a Posterior Approach

Nakamura Shu,Taguchi Mitsuto 대한척추외과학회 2020 Asian Spine Journal Vol.14 No.4

Study Design: A preliminary case series study.Purpose: For the safety of performing a posterior percutaneous full-endoscopic cervical discectomy.Overview of Literature: Because of the lack of space for inserting an outer sheath above the intervertebral disc in the spinal canal, grasping the herniated disc with forceps while retracting the nerves with the forceps itself was required. This procedure produces the risk of inadvertently injuring nerves because of inadequate visualization of the hernia and inadequate protection of the nerve.Methods: Our new internal retractor can be inserted into the working channel of a percutaneous full-endoscope, enabling the insertion of a second tool. After partial foraminotomy, the internal retractor and forceps were manipulated to reliably retract the nerve root. Finally, the herniated disc was resected under an endoscopic view.Results: All six cases had a good postoperative course, and postoperative neuropathy was not observed.Conclusions: This internal retractor allows for the secure resection herniated cervical intervertebral discs.

Percutaneous Endoscopic Cervical Discectomy: Surgical Approaches and Postoperative Imaging Changes

Shu Nakamura,Mitsuto Taguchi 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.2

Study Design: Retrospective clinical study. Purpose: This study investigated the relationship between surgical approaches and surgical outcomes in patients undergoing percutaneous endoscopic cervical discectomy (PECD), including the reduction in intervertebral disc height and the incidence of Modic changes. Overview of Literature: The anterior approach involves partial invasion of the intervertebral disc, with a reported reduction in intervertebral disc height after PECD. Methods: Forty-two patients with cervical disk hernia who underwent PECD and magnetic resonance imaging at least 3 months postoperatively were divided into four groups according to the hernia sites and the surgical approach used: unilateral hernia treated using the contralateral approach (group C, n=18), unilateral hernia treated using the ipsilateral approach (group I, n=15), midline hernia (group M, n=4), and broad and bilateral hernia (group B, n=5). Modic changes and intervertebral disc height were evaluated. Results: The overall incidence of Modic changes was 52.4%: 72.2% in group C, 26.7% in group I, 25.0% in group M, and 80.0% in group B. The reduction in intervertebral disc height was 21.8% across all the patients: 24.5% in group C, 11.0% in group I, 22.8% in group M, and 23.9% in group B. Conclusions: The incidence of Modic changes and the reduction in intervertebral disc height were lower in the patients treated using the ipsilateral approach than in those treated using the contralateral approach. Traditionally, a contralateral approach has been used for PECD; however, the ipsilateral approach is more appropriate and is therefore recommended.

Step-by-Step Sublaminar Approach With a Newly-Designed Spinal Endoscope for Unilateral-Approach Bilateral Decompression in Spinal Stenosis

Fujio Ito,Zenya Ito,Motohide Shibayama,Shu Nakamura,Minoru Yamada,Hideki Yoshimatu,Mikinobu Takeuchi,Kenzo Shimizu,Yasushi Miura 대한척추신경외과학회 2019 Neurospine Vol.16 No.1

Objective: Spinal stenosis is increasingly common due to population aging. In elderly patients with lumbar central canal stenosis (LCCS), minimizing muscle damage and bone resection is particularly important. We performed a step-by-step operation with a newly designed spinal endoscope to obtain adequate decompression in patients with spinal stenosis. Methods: From April 2015 to August 2016, 78 patients (48 males, 30 females) with LCCS (91 segments) underwent endoscopic decompression using a newly designed endoscope system. The inclusion criteria were: (1) neurogenic intermittent claudication with or without radiculopathy, (2) LCCS, and (3) having exhausted conservative treatment (>3 months). The exclusion criteria were: (1) >10° of instability, (2) spondylolisthesis grade II or greater according to the Meyerding criteria, (3) foraminal stenosis, (4) vascular intermittent claudication, (5) infection, and (6) stenosis combined with malignancy. We performed a step-by-step procedure using a newly designed endoscope system for unilateral-approach bilateral decompression. We used the same incision for 2–3 segments, only moving the skin. Results: The mean follow-up was 2.3±1.3 years. Excellent or good results were found according to the MacNab criteria in 85.9% of cases (67 of 78). The visual analogue scale, Japanese Orthopedic Association score, and Oswestry Disability Index showed significant decreases at 1 month, persisting until the 2-year follow-up. Dural tear occurred in 4 cases (5.1%), and patch repair was performed under endoscopy. No patients experienced aggravated instability requiring surgery. Conclusion: We obtained good results with endoscopic decompression surgery using a newly designed instrument that minimized muscle and bone damage in elderly patients with spinal stenosis.

Can Postural Instability Respond to Galvanic Vestibular Stimulation in Patients with Parkinson’s Disease?

Hiroshi Kataoka,Yohei Okada,Takao Kiriyama,Yorihiro Kita,Junji Nakamura,Shu Morioka,Koji Shomoto,Satoshi Ueno 대한파킨슨병및이상운동질환학회 2016 Journal Of Movement Disorders Vol.9 No.1

Objective Galvanic vestibular stimulation (GVS) activates the vestibular afferents, and these changes in vestibular input exert a strong influence on the subject’s posture or standing balance. In patients with Parkinson’s disease (PD), vestibular dysfunction might contribute to postural instability and gait disorders. Methods Current intensity was increased to 0.7 mA, and the current was applied to the patients for 20 minutes. To perform a sham stimulation, the current intensity was increased as described and then decreased to 0 mA over the course of 10 seconds. The patient’s status was recorded continuously for 20 minutes with the patient in the supine position. Results Three out of 5 patients diagnosed with PD with postural instability and/or abnormal axial posture showed a reduction in postural instability after GVS. The score for item 12 of the revised Unified Parkinson’s Disease Rating Scale part 3 was decreased in these patients. Conclusions The mechanism of postural instability is complex and not completely understood. In 2 out of the 5 patients, postural instability was not changed in response to GVS. Nonetheless, the GVS-induced change in postural instability for 3 patients in our study suggests that GVS might be a therapeutic option for postural instability

Biofabrication: reappraising the definition of an evolving field

Groll, Jü,rgen,Boland, Thomas,Blunk, Torsten,Burdick, Jason A,Cho, Dong-Woo,Dalton, Paul D,Derby, Brian,Forgacs, Gabor,Li, Qing,Mironov, Vladimir A,Moroni, Lorenzo,Nakamura, Makoto,Shu, Wenmiao,Ta IOP Publishing 2016 Biofabrication Vol.8 No.1