Posterior Percutaneous Endoscopic Cervical Diskectomy: A Single-Center Experience of 252 Cases

Narrative Review of Uniportal Posterior Endoscopic Cervical Foraminotomy

Cervical radiculopathy is a common and disabling cervical condition characterized by symptoms including axial neck pain, radicular pain, weakness, and numbness in one or both arms. Common causes include herniated discs and foraminal stenosis, often accompanied by varying degrees of degenerative disc disease and uncovertebral joint hypertrophy. In the treatment of cervical radiculopathy, there is an increasing preference for posterior foraminotomy over anterior cervical discectomy and fusion due to the avoidance of fusion-related complications. As endoscopic spine surgery techniques continue to evolve, there is a rising interest in posterior endoscopic cervical foraminotomy and posterior endoscopic cervical discectomy as effective treatments for cervical radiculopathy. Because these procedures can performed through a single subcentimeter incision with minimal soft tissue damage, they can often be carried out as ambulatory procedures. In this narrative review, we examined current literature addressing the indications, surgical techniques, outcomes, and potential complications associated with posterior cervical endoscopic approaches.

Complications of Cervical Endoscopic Spinal Surgery: A Systematic Review and Narrative Analysis

BACKGROUND

There are no systematic evidence-based medical data on the complications of endoscopic cervical spinal surgery. This narrative analysis compiled data from various studies that examined endoscopic complications, such as cervical disc herniation and foraminal stenosis. This study aimed to investigate the efficacy and safety of endoscopic surgery in cervical radiculopathy.

METHODS

We searched the PubMed/MEDLINE databases to identify articles on endoscopic spinal surgery, and keywords were set as "endoscopic cervical spinal surgery", "endoscopic cervical discectomy", "endoscopic cervical foraminotomy", and "percutaneous endoscopic cervical discectomy". We analyzed the evidence level and classified the prescribed complications according to the literature. Endoscopic cervical surgery was divided into three categories: full endoscopic anterior, endoscopic posterior, and unilateral biportal approaches. We excluded duplicate publications, studies without full text, studies without complications or incomplete information, and studies that did not provide the necessary data for extraction, animal experiments, or reviews.

RESULTS

Difficulties in swallowing, hematoma, and hoarseness are common complications associated with the anterior cervical approach. In contrast, complications of the posterior approach include nerve root injury, hematoma, and dysesthesia. However, endoscopic cervical spinal surgery, including the full endoscopic anterior, posterior, and unilateral biportal approaches, is a safe and effective treatment for cervical radiculopathy.

CONCLUSIONS

Complications of full endoscopic cervical spinal surgery differ significantly depending on the anterior and posterior approaches. In the anterior approach, swallowing difficulty, recurrent disc, hematoma, and dysphonia are the common complications. In contrast, transient dysesthesia, dural tears, upper limb motor deficits, and persistent arm pain are commonly reported with the posterior approach.

Complications and Management of Endoscopic Spinal Surgery

In the past, the use of endoscopic spine surgery was limited to intervertebral discectomy; however, it has recently become possible to treat various spinal degenerative diseases, such as spinal stenosis and foraminal stenosis, and the treatment range has also expanded from the lumbar spine to the cervical and thoracic regions. However, as endoscopic spine surgery develops and its indications widen, more diverse and advanced surgical techniques are being introduced, and the complications of endoscopic spine surgery are also increasing accordingly. We searched the PubMed/MEDLINE databases to identify articles on endoscopic spinal surgery, and key words were set as “endoscopic spinal surgery,” “endoscopic cervical foramoinotomy,” “PECD,” “percutaneous transforaminal discectomy,” “percutaneous endoscopic interlaminar discectomy,” “PELD,” “PETD,” “PEID,” “YESS” and “TESSYS.” We analyzed the evidence level and classified the prescribed complications according to the literature. Endoscopic lumbar surgery was divided into full endoscopic interlaminar and transforaminal approaches and a unilateral biportal approach. We performed a comprehensive review of available literature on complications of endoscopic spinal surgery. This study particularly focused on the prevention of complications. Regardless of the surgical methods, the most common complications related to endoscopic spinal surgery include dural tears and perioperative hematoma. transient dysesthesia, nerve root injury and recurrence. However, Endoscopic spinal surgery, including full endoscopic transforaminal and interlaminar and unilateral biportal approaches, is a safe and effective a treatment for lumbar as well as cervical and thoracic spinal diseases such as disc herniation, lumbar spinal stenosis, foraminal stenosis and recurrent disc herniation.

Microscopic Anterior Cervical Discectomy and Fusion Versus Posterior Percutaneous Endoscopic Cervical Keyhole Foraminotomy for Single-level Unilateral Cervical Radiculopathy: A Systematic Review and Meta-analysis

STUDY DESIGN

A systematic review and meta-analysis.

OBJECTIVE

The objective of this study was to compare the safety of microscopic anterior cervical discectomy and fusion (MI-ACDF) and posterior percutaneous endoscopic keyhole foraminotomy (PPEKF) in patients diagnosed with single-level unilateral cervical radiculopathy.

SUMMARY OF BACKGROUND DATA

After conservative treatment, the symptoms will be relieved in about 90% of cervical radiculopathy patients. For the other one tenth of patients, surgical treatment is needed. The overall complication rate of MI-ACDF and PPEKF ranges from 0% to 25%, and the reoperation rate ranges from 0% to 20%.

MATERIALS AND METHODS

Electronic retrieval of studies from PubMed, Embase, and Cochrane Library was performed to identify comparative or single-arm studies on MI-ACDF and PPEKF. A total of 24 studies were included in our meta-analysis by screening according to the inclusion and exclusion criteria. After data extraction and quality assessment of the included studies, a meta-analysis was performed by using the R software. The pooled incidences of efficient rate, total complication rate, and reoperation rate were calculated.

RESULTS

A total of 24 studies with 1345 patients (MI-ACDF: 644, PPEKF: 701) were identified. There was no significantly statistical difference in pooled patient effective rate (MI-ACDF: 94.3% vs. PPEKF: 93.3%, P =0.625), total complication rate (MI-ACDF: 7.1% vs. PPEKF: 4.7%, P =0.198), and reoperation rate (MI-ACDF: 1.8% vs. PPEKF: 1.1%, P =0.312). However, the common complications of the 2 procedures were different. The most common complications of MI-ACDF were dysphagia and vertebral body sinking, whereas the most common complication of PPEKF was nerve root palsy.

CONCLUSIONS

Both MI-ACDF and PPEKF can provide a relatively safe and reliable treatment for single-level unilateral cervical radiculopathy. The 2 techniques are not significantly different in terms of effective rate, total complication rate, and reoperation rate.

Posterior cervical full-endoscopic technique for the treatment of cervical spondylotic radiculopathy with foraminal bony stenosis: A retrospective study

Objective

In the treatment of cervical spondylotic radiculopathy (CSR), spinal endoscopy has been developed vigorously in the past 30 years. However, its effectiveness and subsequent problem of cervical spine stability have always been the controversial hotspots. This study aims to conduct a retrospective study using posterior cervical full-endoscopic technique for the treatment of CSR with foraminal bony stenosis, and evaluate its clinical effect and application value.

Methods

All 22 patients treated for CSR with foraminal bony stenosis using posterior cervical full-endoscopic technique were analyzed since Dec 1, 2016, to Apr 30, 2020. The data collection included operation time, length of stay, wound healing, surgical complications, visual analog scale (VAS), Japanese Orthopaedic Association (JOA) scores, intervertebral foramen diameter, intervertebral foramen area and cervical instability. The relevant indicators were observed on admission, at postoperative 1 week and 3 months, and at the last follow-up.

Results

The operation time was 141.6 ± 13.7 min. The length of stay was 6.0 ± 2.5 days. VAS and JOA at different time points after operation were decreased compared with before operation (p < 0.05). There were no statistical differences between VAS or JOA at different postoperative time points (p > 0.05). The height, anteroposterior diameter and area of intervertebral foramen after operation were significantly increased compared with before operation (p < 0.05).

Conclusion

Posterior cervical full-endoscopic technique shows the advantages of smaller invasion, faster recovery, significant effectiveness and fewer complications in our study. Meanwhile, it has little influence on the ROM and stability of the cervical spine. Therefore, it is a minimally invasive, safe and effective surgical method for the treatment of CSR with foraminal bony stenosis.

Comparison of Percutaneous Endoscopic Cervical Keyhole Foraminotomy versus Microscopic Anterior Cervical Discectomy and Fusion for Single Level Unilateral Cervical Radiculopathy

Objective

To compare the clinical and radiological outcomes between microscopic anterior cervical discectomy and fusion (ACDF) and percutaneous endoscopic cervical keyhole foraminotomy (PECF) for single level unilateral cervical radiculopathy.

Methods

A total of 127 patients (59 in PECF VS 68 in ACDF) were enrolled in this study from April 2016 to May 2018 with a minimum follow-up of 2 years. Clinical data including baseline data, Neck Disability Index (NDI), and Visual Analogue Scale for neck and arm (VAS-n, VAS-a) were collected and compared. Radiological evaluation such as disc height, ROM of cervical, Cobb’s angle of cervical and Cobb’s angle of operated segment was measured by two experienced radiologists in twice.

Results

There was no significant difference between the two groups in the baseline data, and hospital stay was significantly decreased in PECF group than ACDF group (P < 0.001). PECF group did not yield superior better outcomes in NDI, VAS-a and VAS-n than ACDF group except at 1-month follow-up. As for radiological outcomes, PECF group has significantly better cervical motion, cervical angle and segmental angle than ADCF group at 12- and 24-month follow-up visit (P < 0.05); however, ACDF had shown better disc height restoration and maintenance than PECF (P < 0.05). More complications including surface hematoma and swallowing difficulty were occurred in ADCF group.

Conclusion

Percutaneous endoscopic cervical keyhole foraminotomy could be the alternative method for anterior cervical discectomy and fusion in selective cases. However, the indication should be fulfilled, more studies need to be conducted to further testify the efficacy of PECF.

Morphology of Herniated Disc as a Predictor for Outcomes of Posterior Percutaneous Full-endoscopic Cervical Discectomy in Treating Cervical Spondylotic Radiculopathy

Objective

To quantitively characterize the morphology of cervical disc herniation (CDH) causing cervical spondylotic radiculopathy (CSR) and investigate whether the morphological features of CDH are associated with clinical outcomes in CSR patients treated by posterior percutaneous full‐endoscopic cervical discectomy (PPECD).

Methods

This is a single‐center retrospective study. Eighty‐seven PPECD‐treated patients meeting the inclusion criteria were included between May 2017 and May 2019. Based on preoperative T2‐weighted magnetic resonance imaging (MRI), we designed and measured six morphological parameters of CDH for all patients to reflect its relative position to cervical spinal cord and protruding degree: DC‐SC distance from the center of disc (DC) and the center of spinal cord (SC); DC‐DP distance from the center of cervical disc (DC) to the peak of herniation (DP); internal diameter of the disc; axial length of CDH; central angle of CDH formed by central axes of CDH and spinal cord; the modified index of CDH. We recorded general information, neck disability index (NDI) scores, visual analog scale (VAS) scores of neck and arm of all patients preoperatively and postoperatively at 1‐year follow‐up. The association of preoperative general variables and morphological parameters with clinical outcomes were explored by utilizing logistic regression and receiver operating characteristic curve (ROC) analysis.

Results

The preoperative neck‐VAS, arm‐VAS, and NDI were significantly decreased after PPECD and remained at a low value at follow‐up. In regards to the morphological parameters of CDH, the mean value of DC‐SC distance, DC‐DP distance, internal diameter of the disc, axial length of CDH, central angle of CDH, and modified index of CDH were 1.61 ± 0.30 cm, 1.66 ± 0.32cm, 1.04 ± 0.21 cm, 0.63 ± 0.19cm, 39.38° ± 11.94°, and 0.39 ± 0.24, respectively. For patients grouped by difference in the recovery rate of NDI and arm‐VAS (excellent improved group, EI; and limited improved group, LI), there were no differences in the age, gender, surgical segments, and morphological parameters, except for the central angle of CDH. According to binary logistic regression analysis, only the preoperative central angle of CDH was significantly associated with postoperative NDI recovery (odds ratio: 0.873; 95% confidence interval: 0.819–0.931, P = 0.002). ROC analysis showed the optimal cut‐off value of the central angle of CDH for predicting the postoperative improvement of functional outcomes is 33.788°.

Conclusion

Preoperative morphology of CDH is related to the outcomes of CSR patients after PPECD. Patients with a large central angle of CDH (>33.788°) have more likelihood of ameliorating neurological symptoms of CSR. There is the potential to select the central angle of CDH as a predictor for outcomes of PPECD in treating CSR.

Comparative evaluation of posterior percutaneous endoscopy cervical discectomy using a 3.7 mm endoscope and a 6.9 mm endoscope for cervical disc herniation: a retrospective comparative cohort study

Background

Posterior percutaneous endoscopy cervical discectomy (p-PECD) is an effective strategy for the treatment of cervical diseases, with a working cannula ranging from 3.7 mm to 6.9 mm in diameter. However, to date, no studies have been performed to compare the clinical outcomes of the use of endoscopes with different diameters in cervical disc herniation (CDH) patients. The purpose of this study was to compare the clinical outcomes of patients with unilateral CDH treated with p-PECD using a 3.7 mm endoscope and a 6.9 mm endoscope.

Methods

From January 2016 to June 2018, a total of 28 consecutive patients with single-level CDH who received p-PECD using either the 3.7 mm or the 6.9 mm endoscope were enrolled. The clinical results, including the surgical duration, hospitalization, visual analog scale (VAS) score and modified MacNab criteria, were evaluated. Cervical fluoroscopy, CT, and MRI were also performed during follow-up.

Results

Tthere was a significant difference in regard to the average identification time of the “V” point (18.608 ± 3.7607 min vs. 11.256 ± 2.7161 min, p < 0.001) and the mean removal time of the overlying tissue (16.650 ± 4.1730 min vs. 12.712 ± 3.3079 min, p < 0.05) for the use of the 3.7 mm endoscope and the 6.9 mm endoscope, respectively. The postoperative VAS and MacNab scores of the two endoscopes were significantly improved compared with those the preoperative scores (p < 0.05).

Conclusion

The application of both the 3.7 mm endoscope and 6.9 mm endoscope represent an effective method for the treatment of CDH in selected patients, and no significant difference can be observed in the clinical outcomes of the endoscopes. The 6.9 mm endoscope shows superiority to the 3.7 mm endoscope in terms of the efficiency of “V” point identification, the removal of overlying soft tissue and the prevention of spinal cord injury. However, the 6.9 mm endoscope may be inferior to the 3.7 mm endoscope in regards to anterior foraminal decompression due to its large diameter; this result needs to be further evaluated with the support of a large number of randomized controlled trials.

Posterior percutaneous endoscopic versus traditional surgery for cervical disc herniation: A protocol for systematic review and meta analysis

BACKGROUND

Posterior percutaneous endoscopic cervical diskectomy (P-PECD) can be used posterior microdiscectomy for cervical disc herniation. But only some small sample sizes of clinical studies have evaluated the efficacy and safety of P-PECD. This study aim to evaluated the efficacy and safety of P-PECD compared with traditional open surgery.

METHODS

We will search the following seven electronic databases from their initiation to the May 1, 2020: PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (CBM) and Wanfang database. All randomized controlled trials, non-randomized controlled trials and retrospective case controls that compared the efficacy and safety of P-PECD and traditional open surgery in the treatment of cervical disc herniation will be included. The pooled odds ratio with 95% credible intervals (CIs) was used for the dichotomous variables. The mean difference with 95% CIs was used for the continuous variables. All analyses were conducted by Comprehensive Meta Analysis 2.0. A 2-tailed P value < 0.05 is considered statistically significant.

RESULTS

The results of systematic review and meta-analysis will be submitted to a peer-reviewed journal.

CONCLUSION

Our study will provide clarity regarding for clinicians to choices best surgical approach for patients with cervical disc herniation. Any changes that need to be made during the process of this study will be explained in the final full-text publication.

PROTOCOL REGISTRATION NUMBER

CRD42020164011.

The evolution of interlaminar endoscopic spine surgery

Due to the aging population, patients required spinal surgery for degenerative spondylopathy is increasing. With the advent of surgical instruments and techniques, minimally invasive spine surgery is prevalent worldwide. Besides microscopic techniques, endoscopic spine surgery has gotten attention gradually in this surgical field for the past two decades. There are two essential approaches developed currently, including transforaminal and interlaminar approach. These innovative equipment and skills promote the progression of endoscopic surgery from discectomy to decompression of spinal stenosis. Meanwhile, they also opened up the application of endoscopic surgery in a complicated situation. From the perspective of emerging technologies and techniques, the authors will review the evolution and describe the prospects of the interlaminar endoscopic spine surgery (IESS).

A comparison study of posterior cervical percutaneous endoscopic ventral bony decompression and simple dorsal decompression treatment in cervical spondylotic radiculopathy caused by cervical foraminal and/or lateral spinal stenosis: a clinical retrospective study

Background

Percutaneous endoscopic cervical decompression (PECD) is an ideal minimally invasive decompression technique for the treatment of cervical spondylotic radiculopathy (CSR). However, the mainstream is the resection of dorsal bone and removal of free nucleus pulposus. The necessity of excision of ventral osteophytes and hyperplastic ligaments in the treatment of CSR caused by cervical foraminal and/or lateral spinal stenosis (CFa/oLSS) to be discussed.

Methods

We performed a retrospective study of 46 patients with CSR caused by CFa/oLSS from January 2017 to November 2018. These patients received posterior percutaneous endoscopic cervical decompression-ventral bony decompression (PPECD-VBD)(23 cases, classified as VBD group) or posterior percutaneous endoscopic cervical decompression-simple dorsal decompression (PPECD-SDD)(23 cases, classified as SDD group). Following surgery, we recorded Visual Analogue Scale (VAS), Neck Disable Index (NDI), Japanese Orthopaedic Association (JOA) Scores and myodynamia. We further evaluated the changes of cervical curvature and cervical spine motion in the VBD group and recorded the operation time and complications during the follow-up of each patient.

Results

All patients underwent successful operations, with an average follow-up time of 16.53 ± 9.90 months. The excellent and good rates in the VBD and SDD groups were 91.29 and 60.87%, respectively. In the SDD group, neck-VAS, arm-VAS, and NDI scores were significantly higher than those of the VBD group at 1 day, 6 months, and 12 months after surgery (P < 0.05), while the JOA scores and improvement rate of JOA were significantly lower than those of the VBD group (P < 0.05). There were no significant differences in terms of angular displacement (AD), horizontal displacement (HD), segmental angle (SA) and cervical curvature (CA) before and after the operation in the VBD group (P > 0.05).

Conclusion

PPECD-VBD was significantly better than PPECD-SDD as well as PPECD-VBD had no significant effects on cervical spine stability or cervical curvature.

Posterior Unlocking of Facet Joints Under Endoscopy Followed by Anterior Decompression, Reduction, and Fixation of Old Subaxial Cervical Facet Dislocations: A Technical Note

OBJECTIVE

Besides the facet joints interlocking, the fibrous tissue or bony callus around the dislocated segments make the reduction for this kind of old injury to be more challenging and different from that of acute injuries. This study is aimed to present 4 cases of old subaxial cervical facet dislocations (SCFD) that were successfully treated with posterior unlocking under endoscopy followed by anterior decompression, reduction, and fixation.

METHODS

Between January 2017 and December 2017, 4 patients with old SCFD who underwent posterior unlocking of facet joints under endoscopy followed by anterior decompression, reduction, and fixation were enrolled. A cervical collar was prescribed for 4 weeks postoperatively. Postoperative follow-up evaluations were conducted at 2, 6, and 12 months, including neck visual analogue scale score and neck disability index, radiography, and computed tomography.

RESULTS

The operative time averaged 145 minutes (range, 130-155 minutes). No deterioration of neural function, major vessel rupture, or iatrogenic injury to esophagus occurred. Intraoperative blood loss averaged 45 mL (range, 40-50 mL). Hospital stay for all patients was only 4 days. The neck visual analogue scale score and neck disability index were improved at the final follow-up, and interbody fusion was satisfactory without any radiologic sign of instability or internal failure.

CONCLUSIONS

For patients with old SCFD, the unlocking of facet joints via the posterior approach under endoscopy followed by anterior decompression, reduction, and fixation is an alternative technique.

Posterior Percutaneous Endoscopic Cervical Diskectomy as a treatment for cervical radiculopathy

Anterior cervical diskectomy and fusion (ACDF) is the gold standard treatment for patients with cervical radiculopathy. However, the use of ACDF for patients with cervical radiculopathy can result in several disadvantages, such as limitation of motion and accelerating degeneration of adjacent segment. An alternative, less invasive endoscopic technique, posterior percutaneous endoscopic cervical diskectomy (PPECD), was applied to address the above problems associated with ACDF. The patient presented with pain and weakness of the left arm for 2 years. P-PECD was applied and complete decompression of the nerve root was achieved. The symptoms were relieved after surgery. Postoperative MR showed the ruptured disk fragment was successful removed. No spinal instability or symptom relapse was observed in follow-up. PPECD may be an option for patients with cervical radiculopathy.

Current state of minimally invasive spine surgery

Over the past two decades, minimally invasive surgical approaches have become increasingly feasible, efficient and popular for the management of a wide range of spinal disorders, with a growing body of research demonstrating numerous advantages of these techniques over the traditional open approach. In this article, we review the technologies and innovations that are expanding the horizon of minimally invasive spine surgery (MISS), and highlight high-quality peer-reviewed literature in the past year that expands our knowledge and understanding of indications, advantages and limitations of MISS.

Anatomical Relationship of the Vertebral Artery With the Lateral Recess: Clinical Importance for Posterior Cervical Foraminotomy

Objective

Vertebral artery injuries during posterior cervical foraminotomy are rare, but can be fatal. Therefore, we investigated the anatomical correlation between the lateral recess and the vertebral artery.

Methods

On axial cuts of cervical magnetic resonance imaging from 108 patients, we measured the distance between the vertebral arteries and the medial border of the facet joints. The anatomical vertebro-facet distance (AVFD), surgical vertebro-facet distance (SVFD), and vertebro-facet angle (VFA) were measured.

Results

The mean AVFD values on the right side at the C3–4, C4–5, C5–6, and C6–7 levels showed statistically significant differences. On the right side, the mean SVFD values were equivalent to the AVFD values. The mean values of the VFA on the right side at all levels showed statistically significant differences. For all measurements, the greatest differences were seen between the C5–6 and C6–7 levels, and higher levels were associated with smaller distances from the lateral recess. The mean values of the AVFD on the right and left sides showed statistically significant differences at all levels, and the distances on the left were smaller than those on the right.

Conclusion

The vertebral artery is closer to the lateral recess at higher cervical levels than at lower cervical levels. The largest distances were found at the C5–6 and C6–7 levels, and the left vertebral arteries were closer to the lateral recess than the right vertebral arteries.