Postoperative Outcomes After Transsacral Epiduroscopic Laser Decompression in Japanese Patients: Denervation Therapy for Discogenic Low-Back Pain.

Background: Transsacral epiduroscopic laser decompression (SELD) is a very noninvasive surgery, so it is effective for elderly patients and athletes and is a new and minimally invasive therapeutic technique that may be useful in many patients with discogenic low-back pain (LBP) having high signal intensity zone (HIZ) in magnetic resonance imaging (MRI). We investigated the clinical outcomes of SELD in Japanese patients with discogenic LBP having HIZ as a first trial. Methods: The subjects consisted of 52 patients who underwent SELD and were followed up for at least 6 months. All patients with LBP with HIZ were operative using the SELD technique. Outcomes of the patients were assessed with visual analogue scale (VAS) for LBP, the Oswestry disability index (ODI), and the EuroQol 5 dimension (EQ-5D). Statistical analyses were carried out using a paired t-test. A p-value of <0.05 was considered significant. For statistical analysis, we used the SPSS software program. Results: At 12 months after the procedure, the average VAS score for LBP fell to 1.2 from 5.6 (p-value <0.05). The ODI score also dropped from the preoperative level of 22.3 to 8.8. The EQ-5D score also significantly increased from the preoperative level of 0.865 (SD 0.10) to 0.950 (SD 0.05). Eight cases of intraoperative cervical pain were observed as complications with no cases of hematomas, infections, and postoperative neurosis was observed. Conclusions: SELD provides a novel minimally invasive technique capable of performing multilevel intervertebral surgery. We believe that SELD is an effective method of treating discogenic LBP due to HIZs.

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

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.

A New Percutaneous Endoscopic Instrument for Far-migrated Disk Herniation: A Retrospective Single-Institution Study.

OBJECTIVE: Compared with the traditional posterior approach, the transforaminal (TF) approach for percutaneous endoscopic lumbar diskectomy (PELD) in patients with disk herniation has a limited resection range that is problematic to treat far-migrated disk herniation. This study examined the usefulness of a newly developed percutaneous endoscopic instrument for far-migrated disk herniation. METHODS: This retrospective study included 22 patients with migrated disk herniation ≥ 10 mm who underwent transforaminal PELD using the new instrument between August 2014 and May 2017. The new instrument differs from conventional forceps because it has only one jaw that rotates in a plane perpendicular to the mouth opening. The migrated herniated disk is held between the instrument and bone surface, pulled out, and subsequently removed using conventional forceps. RESULTS: Herniated disks that had migrated up to 16 mm were removed successfully in all patients. CONCLUSIONS: The new instrument is a useful tool that can expand the resection range of the TF approach for PELD.

Percutaneous Endoscopic Cervical Discectomy: Surgical Approaches and Postoperative Imaging Changes.

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.

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

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 cross-sectional 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 cross-sectional area of the intervertebral foramen around the lateral edge of the resection area (SALE) was measured and compared wit 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.

Full Percutaneous Lumbar Interbody Fusion: Technical Note.

Introduction: Although lumbar interbody fusion is effective for low back pain caused by severe disk degeneration, it is a highly invasive procedure. Less invasive procedures such as transforaminal lumbar interbody fusion (TLIF) and lumbar lateral interbody fusion have become available; however, there is still scope for improvement. We performed full percutaneous endoscopic lumbar interbody fusion (PELIF), a technique designed as a safe and less invasive percutaneous fusion. Method and Subjects: Our technique is indicated for patients with chronic low back pain in whom conservative treatment was not effective, thinning of the intervertebral disk was prominent, and temporary pain relief was achieved with a disk block. In the operation, percutaneous endoscopic diskectomy was performed with a 7.5-mm sheath inserted through a small incision, and a cage was inserted percutaneously using an L-shaped retractor. Instead of pedicle screw fixation, hybrid facet screw fixation was performed. Low back pain was improved, and bone union was confirmed on radiography. This technique was used in six patients, and no surgery-related complications occurred. Discussion: The L-shaped retractor used in this series can protect the exiting nerve by inserting it into the sheath, then removing the sheath and placing the rounded corner of the retractor on the lateral cranial side. This technique is safe with no other associated risks. Cages larger than the sheath can be inserted, and commercially available cages for TLIF are applicable. Hybrid facet screw fixation can overcome the problems associated with both conventional transfacet pedicle screw fixation and translaminar facet screw fixation by combining these two procedures. Conclusion: PELIF is an easy, safe, and fully percutaneous technique with very low invasiveness that uses an L-shaped retractor and hybrid facet screw fixation. This procedure can be a treatment option for patients with severe low back pain related to disk degeneration.

Urokinase-Treated Antithrombogenic Drains and Optimized Drain Placement in Endoscopic Lumbar Decompressive Surgery.

Background Spinal epidural hematoma (SEH) frequently occurs after microendoscopic decompressive laminotomy (MEDL), and a drain may not be functioning sufficiently. Objective To reduce the incidence of SEH after MEDL. Methods A urokinase-treated antithrombogenic drain, which is available only with a large diameter, was reduced in diameter and used after MEDL. Magnetic resonance imaging (MRI) and computed tomography (CT) were performed 36 to 48 hours after surgery. The size of the SEH was measured by MRI, and the location of the drain tip was assessed by CT scan. After imaging, the drain was removed. Results Use of the urokinase-treated antithrombogenic drain reduced the incidence of SEH. However, the drain was not adequately placed in many cases, limiting the effect of the drainage. When the urokinase-treated antithrombogenic drain was placed contralaterally to the approach side using an unsheathed endoscope, the incidence of SEH was further reduced. Conclusions The urokinase-treated antithrombogenic drain prevented thrombus-related drain obstruction. In addition, unsheathed endoscopic contralateral placement of the drain was effective for SEH prevention.