Factors predicting excellent outcome of percutaneous cervical discectomy: analysis of 111 consecutive cases

Evolution, Current Trends, and Latest Advances of Endoscopic Spine Surgery

Background: The aging of the population in developing and developed countries has led to a significant increase in the health burden of spinal diseases. These elderly patients often have a number of medical comorbidities due to aging. The need for minimally invasive techniques to address spinal disorders in this elderly population group cannot be stressed enough. Minimally invasive spine surgery (MISS) has several proven benefits, such as minimal muscle trauma, minimal bony resection, lesser postoperative pain, decreased infection rate, and shorter hospital stay. Methods: A comprehensive search of the literature was performed using PubMed. Results: Over the past 40 years, constant efforts have been made to develop newer techniques of spine surgery. Endoscopic spine surgery is one such subset of MISS, which has all the benefits of modern MISS. Endoscopic spine surgery was initially limited only to the treatment of lumbar disc herniation. With improvements in optics, endoscopes, endoscopic drills and shavers, and irrigation pumps, there has been a paradigm shift. Endoscopic spine surgery can now be performed with high magnification, thus allowing its application not only to lumbar spinal stenosis but also to spinal fusion surgeries and cervical and thoracic pathology as well. There has been increasing evidence in support of these newer techniques of spine surgery. Conclusions: For this report, we studied the currently available literature and outlined the historical evolution of endoscopic spine surgery, the various endoscopic systems and techniques available, and the current applications of endoscopic techniques as an alternative to traditional spinal surgery.

Pros and Cons of Minimally Invasive Spine Surgery

This paper reviews current knowledge on minimally invasive spine surgery (MISS). Although it has significant advantages, such as less postoperative pain, short hospital stay, quick return to work, better cosmetics, and less infection rate, there are also disadvantages. The long learning curve, the need for special instruments and types of equipment, high costs, lack of tactile sensation and biplanar imaging, some complications that are hard to treat, and more radiation to the surgeon and surgical team are the disadvantages.Most studies remark that the outcomes of MISS are similar to traditional surgery. Although patients demand it more than surgeons, we predict the broad applications of MISS will replace most of our classical surgical approaches.

Anterior Endoscopic Cervical Discectomy: Surgical Technique and Literature Review

The conventional surgical technique for radiculopathy with cervical disc herniation (CDH) is anterior cervical discectomy and fusion, with a good clinical outcome and fusion rate. However, significant perioperative morbidity related to extensive surgical exposure has been reported. Therefore, anterior endoscopic cervical discectomy (AECD) using a working channel endoscope has been developed to reduce surgical complications and tissue damage. The objective of this study was to describe a cutting-edge technique for AECD of soft CDH. The primary indication is cervical radiculopathy with or without axial neck pain due to soft CDH. The surgical procedure consists of 2 parts: (1) a safe anterior percutaneous approach under fluoroscopic control and (2) selective endoscopic discectomy and foraminal decompression using specialized mechanical tools under endoscopic visualization. The clinical outcomes are comparable to those of conventional surgery and show the benefits of minimally invasive spine procedure. Perioperative data revealed typical minimalism, including reduced muscle damage, blood loss, operative time, and recovery time. With technical advancements in surgical instruments and optics, AECD will become more practical and safer. AECD is effective in selected CDH cases with cervical radiculopathy. However, high-quality clinical studies are needed to verify the effectiveness of this endoscopic cervical spinal procedure.

Efficacy and safety of percutaneous endoscopic cervical discectomy for cervical disc herniation: a systematic review and meta-analysis

BACKGROUND

Since there are currently no systematic evidence-based medical data on the efficacy and safety of PECD, this meta-analysis pooled data from studies that reported the efficacy or safety of PECD for cervical disc herniation to examine the efficacy, recurrence and safety of using PECD to treat cervical disc herniation.

METHODS

We searched the PubMed, EMBASE and Cochrane Library databases for studies published from inception to July 2022. Nine nonrandomized controlled trials (non-RCTs) that reported the efficacy or safety of percutaneous endoscopic cervical discectomy for cervical disc herniation were included. We excluded duplicate publications, studies without full text, studies with incomplete information, studies that did not enable us to conduct data extraction, animal experiments and reviews. STATA 15.1 software was used to analyse the data.

RESULTS

The proportions of excellent and good treatment results after PECD for CDH were 39% (95% CI: 31-48%) and 47% (95% CI: 34-59%), respectively. The pooled results showed that the VAS scores at 1 week post-operatively (SMD = -2.55, 95% CI: - 3.25 to - 1.85) and at the last follow-up (SMD = - 4.30, 95% CI: - 5.61 to - 3.00) after PECD for cervical disc herniation were significantly lower than the pre-operative scores. The recurrence rate of neck pain and the incidence of adverse events after PECD for cervical disc herniation were 3% (95% CI: 1-6%) and 5% (95% CI: 2-9%), respectively. Additionally, pooled results show that the operative time (SMD = - 3.22, 95% CI: - 5.21 to - 1.43) and hospital stay (SMD = - 1.75, 95% CI: - 2.67to - 0.84) were all significantly lower for PECD than for ACDF. The pooled results also showed that the proportion of excellent treatment results was significantly higher for PECD than for ACDF (OR = 2.29, 95% CI: 1.06-4.96).

CONCLUSION

PECD has a high success rate in the treatment of CHD and can relieve neck pain, and the recurrence rate and the incidence of adverse events are low. In addition, compared with ACDF, PECD has a higher rate of excellent outcomes and a lower operative time and hospital stay. PECD may be a better option for treating CHD.

Biportal endoscopic spine surgery for cervical disk herniation: A technical notes and preliminary report

Biportal endoscopic spine surgery (BESS) for cervical disk herniation (CDH) has been rarely reported. The aim of the article is to describe a novel BESS as a posterior approach for CDH and report the preliminary outcomes and complications. This single-centered retrospective chart review included 109 consecutive patients who underwent BESS for symptomatic single-level CDH. Working and viewing portals were created in each unilateral paravertebral area at the target disk level. Endoscopic exploration allowed for effective and minimally invasive decompression via safe access to the medial foramen with minimal laminectomy and facetectomy. Clinical outcomes, including the visual analog scale, neck disability index, Macnab criteria, and the motor function of the involved arm, were evaluated at 4, 8, 12, and 24 postoperative weeks. Visual analog scale and neck disability index improved significantly at 24 weeks postoperatively (P < .01). According to the Macnab criteria, "excellent," "good," and "fair" results were obtained for 55.9%, 30.3%, and 13.8% of patients, respectively. The post 24-week distribution of the involved upper extremity strength grade was significantly improved compared to the initial value (P = .02). One patient had a motor weakness with a decreased grade over 4 weeks from excessive irrigation. The posterior approach of BESS was efficient and feasible for the treatment of CDH.

Patient selection criteria for percutaneous anterior cervical laser versus endoscopic discectomy

BACKGROUND

Percutaneous anterior laser and anterior endoscopic cervical spine surgery are associated with less approach trauma than conventional open cervical spine surgery. The literature illustrating their appropriate use corroborated with objective outcome evidence is scarce. The authors were interested in comparing the clinical outcomes following percutaneous laser disc decompression (PLDD) versus percutaneous endoscopic disc decompression (PEDD). © 2021 Wiley Periodicals LLC.

MATERIALS AND METHODS

Thirty patients with soft contained symptomatic cervical disc herniations and an average age of 50.5 years (range 26 - 68 years; 16 males and 14 females) were prospectively enrolled in 2 groups of 15 patients to be either treated with PLDD or PEDD. All patients underwent PLDD or PEDD under local anesthesia and sedation. Clinical outcomes were assessed with the Macnab criteria VAS score for arm pain. Complications and reoperations were recorded.

RESULTS

There were significant reductions in the VAS score for arm pain from preoperative 8.4 ± 2.5 to 3.1 ± 1.2 in the PLDD group (P < 0.03), and from preoperative 8.6 ± 2.7 to 2.4 ± 1.1 (P < 0.01) in the PEDD group. In the PLDD group, Macnab outcomes were excellent in 21% of patients, good in 44%, fair in 21%, and poor in 14%. In the PEDD group, Macnab outcomes were excellent in 14% of patients, good in 32%, fair in 12%, and poor in the remaining 12%. There were no statistically significant differences in clinical outcomes between the PLDD and the PEDD group. There were no approach-related or surgical complications.

CONCLUSIONS

Tissue trauma is significantly reduced with laser and endoscopic surgery techniques. PLDD and PEDD are both suitable for the specific indication of soft, symptomatic contained cervical disc herniations. The authors' small prospective cohort study indicates that PLDD and PEDD are options for cervical decompression surgery when medical comorbidities or preferences by patients and surgeons dictate more minimally invasive strategies.

Parametric study of anterior percutaneous endoscopic cervical discectomy (APECD)

Anterior percutaneous endoscopic cervical discectomy (APECD) is a common treatment for cervical spondylotic radiculopathy (CSR). In this study, the effects of various channel diameters and approach angles on cervical vertebrae on postoperative outcomes in APECD surgery were explored. A finite element model of intact cervical C₃-C₇ was constructed and then modified to obtain six surgical models. Range of motion (ROM) and intradiscal pressure (IDP) were calculated under different conditions of flexion (Fle), extension (Ext), lateral bending, and axial rotation. During Fle and bending to the left (LB), the ROM was closer to the intact model when the angle of approach was 90°. During bending to the left (LB) and rotation to the left (LR), the ROM changed considerably (43.2%, 33.7%, respectively) where the angle of approach was 45°. As the surgical channel diameter increased, the extent of the change in ROM compared with the intact model also increased. IDP decreased by 48% and 49%, respectively, compared with the intact model at the C₅-C₆ segment where the angle of approach was 45° and 60° during Fle, while it changed little at 90°, by less than 10%. The IDP was increased noticeably by 117.6%, 82.1%, and 105.8%, for channel diameters of 2, 3 and 4 mm, respectively. And declined noticeably during LB and LR (LB: 27.1%, 27.1%, 38.5%; LR: 37.4%, 35.5%, 48.7%). The results demonstrated that the shorter the surgical path, the smaller surgical diameter, the less the biomechanical influence on the cervical vertebra.

A Historical Review of Endoscopic Spinal Discectomy

As an essential component of minimally invasive spine surgery, endoscopic spine surgery (ESS) has continuously evolved and has been accepted as a practical procedure by the worldwide spine community. Especially for lumbar disc herniation (LDH), the percutaneous endoscopic or full-endoscopic discectomy technique has been scientifically proven through randomized controlled trials and meta-analyses to be a good alternative to open discectomy. The initial concept of endoscopic spine discectomy was concerned with indirect disc decompression using various instruments such as blind forceps, a nucleotome, laser, radiofrequency coblation, and some chemical agents. The main surgical field has been shifted from the intradiscal space to the epidural space. Precise and selective discectomy for extruded LDH in the epidural space under high-quality endoscopic visualization is now feasible. Furthermore, the medical applications of ESS is broadening to include spinal stenosis, segmental instability, infection, and even intradural lesions. In this review article, I describe the history of endoscopic spine discectomy and decompression techniques, as well as evolution of the paradigm. This history may help indicate the future of practical ESS.

Percutaneous cervical discectomy: retrospective comparison of two different techniques

AIM

To compare clinical success and patient satisfaction of percutaneous cervical nucleoplasty (PCN) and percutaneous cervical discectomy (PCD) in contained cervical disc herniation treatment.

MATERIALS AND METHODS

We retrospectively identified 50 consecutive patients in our institution: 24 underwent the PCD treatment and 26 patients were treated by the PCN procedure. All patients complained of radicular pain with or without neck pain; diagnosis of contained cervical disc herniation was obtained by MRI; all patients had received conservative therapy which did not result in symptom improvement. Exclusion from our series consisted of patients who had undergone previous surgery at the indicated level, or those with myelopathy, or those in whom more than a sole herniation was treated in the same session. Overall procedure time, fluoroscopy time, radiation dose and complications were recorded. The MacNab scale score was used to assess clinical success in terms of pain relief at 2- and 6-month follow-up. After 4-6 months, a cervical MRI was obtained in 24 patients.

RESULTS

Neither major nor minor complications were reported. Regarding patient satisfaction, overall median modified MacNab score was excellent both at 2 and 6 months after treatment. No significant statistical difference was found in mean modified MacNab score at 2 and 6 months among patients grouped by treatment choice (p = 0.319 and 0.847, respectively); radiation dose was inferior in PCN group than in PCD, with no significant statistical difference.

CONCLUSION

PCD and PCN were found to be safe and effective in terms of pain relief in contained cervical herniation treatment.

AOSpine Consensus Paper on Nomenclature for Working-Channel Endoscopic Spinal Procedures

STUDY DESIGN

International consensus paper on a unified nomenclature for full-endoscopic spine surgery.

OBJECTIVES

Minimally invasive endoscopic spinal procedures have undergone rapid development during the past decade. Evolution of working-channel endoscopes and surgical instruments as well as innovation in surgical techniques have expanded the types of spinal pathology that can be addressed. However, there is in the literature a heterogeneous nomenclature defining approach corridors and procedures, and this lack of common language has hampered communication between endoscopic spine surgeons, patients, hospitals, and insurance providers.

METHODS

The current report summarizes the nomenclature reported for working-channel endoscopic procedures that address cervical, thoracic, and lumbar spinal pathology.

RESULTS

We propose a uniform system that defines the working-channel endoscope (full-endoscopic), approach corridor (anterior, posterior, interlaminar, transforaminal), spinal segment (cervical, thoracic, lumbar), and procedure performed (eg, discectomy, foraminotomy). We suggest the following nomenclature for the most common full-endoscopic procedures: posterior endoscopic cervical foraminotomy (PECF), transforaminal endoscopic thoracic discectomy (TETD), transforaminal endoscopic lumbar discectomy (TELD), transforaminal lumbar foraminotomy (TELF), interlaminar endoscopic lumbar discectomy (IELD), interlaminar endoscopic lateral recess decompression (IE-LRD), and lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD).

CONCLUSIONS

We believe that it is critical to delineate a consensus nomenclature to facilitate uniformity of working-channel endoscopic procedures within academic scholarship. This will hopefully facilitate development, standardization of procedures, teaching, and widespread acceptance of full-endoscopic spinal procedures.

Percutaneous Endoscopic Cervical Discectomy Versus Anterior Cervical Discectomy and Fusion: A Comparative Cohort Study with a Five-Year Follow-Up

Percutaneous endoscopic cervical discectomy (PECD) is an effective minimally invasive surgery for soft cervical disc herniation in properly selected cases. The current gold standard is anterior cervical discectomy and fusion (ACDF). However, few studies have evaluated the outcome of PECD compared with ACDF. We compared the surgical results of PECD and ACDF. Data from patients treated with single-level PECD (n = 51) or ACDF (n = 64) were analyzed. Patients were prospectively entered into the clinical database and their records were retrospectively reviewed. Perioperative data and clinical outcomes were evaluated using the visual analogue scale (VAS), Neck Disability Index (NDI), and modified Macnab criteria. VAS and NDI results significantly improved in both groups. The rates of excellent or good results were 88.24% and 90.63% in the PECD and ACDF group, respectively. The revision rates were 3.92% and 1.56% in the PECD and ACDF group, respectively. Operative time, hospital stay, and time to return to work were reduced in the PECD group compared to the ACDF group (p < 0.001). The five-year outcomes of PECD were comparable to those of conventional ACDF. PECD provided the typical benefits of minimally invasive surgery and may be an effective alternative for treating soft cervical disc herniation.

Cervical endoscopic spinal surgery: A review of the current literature

Cervical endoscopic spinal surgery (CESS) is now regularly performed in some centres in the Far East, yet rarely in Europe and the United States. This review describes the application of CESS through anterior and posterior approaches with analysis of the available evidence supporting current techniques. An electronic literature search identified 52 papers and proceedings' abstracts of which 25 (16 anterior approach and 9 posterior approach) provided comparable clinical outcomes. The results revealed a good or excellent outcome from CESS in 91% (range 74-100%) with a complication rate of 5%. In a local cohort study, patients had 72% less neck pain (visual analogue scale rating) and 81% less arm pain at 6 months when CESS was used as an isolated procedure, and 74% less neck pain and 83% less arm pain when coupled with disc replacement or fusion at an adjacent level.

Posterior percutaneous endoscopic cervical discectomy through lamina-hole approach for cervical intervertebral disc herniation

BACKGROUND

The optimal PECD surgical approach for cervical intervertebral disc herniation (CIVDH) remains controversial. The conventional posterior K-hole approach for PECD leads to damage of facet joint.

OBJECTIVES

This article is to first describe a novel posterior lamina-hole approach of percutaneous endoscopic cervical discectomy (PECD) for CIVDH. The objective of this study is to evaluate the feasibility and short-term clinical effect of this approach.

METHODS

Single-center retrospective observational study of all patients managed with posterior percutaneous endoscopic cervical discectomy (PPECD) using the lamina-hole approach for symptomatic single-level CIVDH between January 2015 and January 2016. The clinical outcomes were evaluated with the visual analog scale, modified MacNab criteria and radiographical results.

RESULTS

Twelve patients (seven women, five men) were enrolled in the study. Positive clinical response for pain relief was achieved in these patients receiving PPECD through lamina-hole approach for CIVDH. Postoperative MRI showed complete removal of the disc material in all the patients, no failure due to residual fragment was observed.

CONCLUSION

As an alternative surgical approach of PPECD, PPECD through lamina-hole approach is a novel access for CIVDH and may be considered a valid and safe therapeutic option for CIVDH. The advantages of this approach are not only providing a valid and secure access to herniated cervical intervertebral fragment but also avoiding the iatrogenic damage to the facet joint and relevant functional spinal unit (FSU). Theoretically, the potential of secondary degeneration of FSU is low.

Percutaneous endoscopic cervical discectomy: a technical review

The treatment of cervical disc herniations has evolved in the last 2 decades. While the anterior cervical discectomy and fusion continues being the gold standard for the treatment of radicular pain triggered by cervical disc herniation, other surgical approaches have been developed. Percutaneous endoscopic cervical discectomy has demonstrated the ability to decompress the exiting nerve root and dural sac correctly and encouraging clinical outcomes has been reported in the literature. One of the most important advantages offered by the endoscopic technique is the capability to resolve the patient's symptoms without the need for interbody fusion. Also, a specific and selective decompression under continuous visualization with minimal surgery-related trauma can be achieved. There are two percutaneous endoscopic cervical discectomy approaches: anterior and posterior. The decision to perform each other depends on pathology site. However, the endoscopic technique requires previous surgical training, a steep learning curve, and proper patient selection. The development of new hardware such as endoscopes with better optics, lighting systems, and endoscopic surgical tools have allowed using endoscopic techniques in more complex cases. The objective of this review is the technical description of the anterior and posterior percutaneous endoscopic cervical discectomy.

Modified posterior percutaneous endoscopic cervical discectomy for lateral cervical disc herniation: the vertical anchoring technique

PURPOSE

During the long-term practice of percutaneous endoscopic cervical discectomy (PECD) at our institution, we have modified the protocol to include the vertical anchoring technique (VAT), which we will describe in detail in this article. The objective of this study was to compare the clinical outcomes associated with the conventional posterior PECD technique with that associated with the modified technique to determine the safety and efficacy of the latter technique.

METHODS

From December 2014 to January 2016, a total of 44 patients with single cervical disc herniation were randomly divided into two groups. One group underwent conventional posterior PECD, and the other group underwent posterior PECD combined with VAT. The operative time, fluoroscopy times and perioperative complications were recorded. The visual analog scale (VAS) for neck and arm pain and the modified MacNab criteria at 1 day, 3, 6, and 12 months after surgery were used to evaluate the postoperative outcomes.

RESULTS

All patients underwent surgery successfully without severe complications. The operative time and intraoperative fluoroscopy times were significantly less in patients treated with VAT than in those who underwent conventional posterior PECD (P < 0.05). Both types of surgery significantly improved the symptoms of patients. According to the results of the follow-up period, there were no significant differences in VAS scores for neck and arm pain or the modified MacNab criteria between the two groups (P > 0.05). There was no recurrence in either group during the follow-up period.

CONCLUSIONS

Although the clinical outcomes of the two surgical techniques were similar, the VAT decreased the operative time and intraoperative fluoroscopy times in posterior PECD surgery. The learning curve for posterior PECD could be shortened by using the VAT. These slides can be retrieved under Electronic Supplementary Material.

Percutaneous cervical laser diskectomy, thermoannuloplasty, and thermonucleoplasty; comparable results without surgery

BACKGROUND

Utilizing the literature, the results of three different minimally invasive surgery (MIS) anterior cervical percutaneous operations for neck/mild radicular pain and magnetic resonance (MR)-documented "contained" (not extruded/sequestrated) discs were evaluated. Results were compared with patients treated nonsurgically for comparable/greater neurological compromise, and even more severe cervical disc disease.

METHODS

There were three MIS percutaneous anterior cervical discectomy procedures. Anterior cervical laser discectomy ablated and vaporized disc tissue. The thermoannuloplasty used heat to contract collagen fibers to reduce disc volume. Thermonucleoplasty employed a low-temperature resister probe to promote disintegration and evacuation of small volumes of disc (e.g., some studies cited an average of just 0.09 mL of disc removed). These results were compared to those for the nonsurgical management of patients with comparable/greater neurological deficits, and more severe cervical disc herniations.

RESULTS

The three MIS anterior cervical operations resulted in 80-90%+ improvement using Macnab's criteria. However, although the literature demonstrated similar 80-90+% improvement without cervical surgery, the latter patients were more neurologically compromised.

CONCLUSIONS

For patients with pain alone/mild radiculopathy and "contained" discs on MR, three MIS percutaneous anterior cervical disc operations resulted in 80-90%+ improvement. Notably, similar 80-90%+ improvement was observed for comparable/more neurologically impaired patients with even larger cervical disc herniations treated nonsurgically. With such findings, where is the "value added" for these three MIS cervical operations?

Percutaneous endoscopic cervical discectomy using working channel endoscopes

Percutaneous endoscopic cervical discectomy has evolved as an efficient, minimally invasive spine surgery for cervical disc herniation or radiculopathy. The development of the working channel endoscope makes definitive decompression surgery through a percutaneous approach feasible. There are two methods of approach to target the pathology: anterior and posterior approach. The approach can be determined according to the zone of pathology or the surgeon's preference. The most significant benefits of this endoscopic surgical technique are minimal access tissue trauma and early recovery from the intervention. However, this technique is still evolving and have a steep learning curve. Extensive development of surgical technique and working channel endoscopes will enable us to treat cervical disc herniation more practically. The objective of this review is to describe the cutting-edge techniques of endoscopic surgery in the cervical spine and to discuss the pros and cons of these minimally invasive surgical techniques.

Biomechanical evaluation of an interfacet joint decompression and stabilization system

A majority of the middle-aged population exhibit cervical spondylosis that may require decompression and fusion of the affected level. Minimally invasive cervical fusion is an attractive option for decreasing operative time, morbidity, and mortality rates. A novel interfacet joint spacer (DTRAX facet screw system, Providence Medical) promises minimally invasive deployment resulting in decompression of the neuroforamen and interfacet fusion. The present study investigates the effectiveness of the device in minimizing intervertebral motion to promote fusion, decompression of the nerve root during bending activity, and performance of the implant to adhere to anatomy during repeated bending loads. We observed flexion, extension, lateral bending, and axial rotation resonant overshoot mode (ROM) in cadaver models of c-spine treated with the interfacet joint spacer (FJ spacer) as stand-alone and supplementing anterior plating. The FJ spacer was deployed bilaterally at single levels. Specimens were placed at the limit of ROM in flexion, extension, axial bending, and lateral bending. 3D images of the foramen were taken and postprocessed to quantify changes in foraminal area. Stand-alone spacer specimens were subjected to 30,000 cycles at 2 Hz of nonsimultaneous flexion-extension and lateral bending under compressive load and X-ray imaged at regular cycle intervals for quantitative measurements of device loosening. The stand-alone FJ spacer increased specimen stiffness in all directions except extension. 86% of all deployments resulted in some level of foraminal distraction. The rate of effective distraction was maintained in flexed, extended, and axially rotated postures. Two specimens demonstrated no detectable implant loosening (<0.25 mm). Three showed unilateral subclinical loosening (0.4 mm maximum), and one had subclinical loosening bilaterally (0.5 mm maximum). Results of our study are comparable to previous investigations into the stiffness of other stand-alone minimally invasive technologies. The FJ spacer system effectively increased stiffness of the affected level comparable to predicate systems. Results of this study indicate the FJ spacer increases foraminal area in the cervical spine, and decompression is maintained during bending activities. Clinical studies will be necessary to determine whether the magnitude of decompression observed in this cadaveric study will effectively treat cervical radiculopathy; however, results of this study, taken in context of successful decompression treatments in the lumbar spine, are promising for the continued development of this product. Results of this biomechanical study are encouraging for the continued investigation of this device in animal and clinical trials, as they suggest the device is well fixated and mechanically competent.

Anterior or posterior approach of full-endoscopic cervical discectomy for cervical intervertebral disc herniation? A comparative cohort study

STUDY DESIGN

This is a retrospective comparative cohort study.

OBJECTIVE

To compare the outcomes of patients with symptomatic cervical intervertebral disc herniation (CIVDH) treated with full-endoscopic cervical discectomy (FECD) using the anterior approach with those treated with the posterior approach.

SUMMARY OF BACKGROUND DATA

The optimal FECD surgical approach for CIVDH remains controversial.

METHODS

From March 2010 to July 2012, a total of 84 consecutive patients with symptomatic single-level CIVDH who underwent FECD using the anterior approach (42 patients) or the posterior approach (42 patients) were enrolled. Patients were assessed neurologically before surgery and followed up at regular outpatient visits. The clinical outcomes were evaluated using the visual analogue scale and the modified MacNab criteria. Radiographical follow-up included the static and dynamic cervical plain radiographs, computed tomographic scans, and magnetic resonance images.

RESULTS

In both groups, shorter mean operative time (63.5 min vs. 78.5 min), increased mean volume of disc removal (0.6 g vs. 0.3 g), larger mean decrease in the final postoperative mean intervertebral vertical height (1.0 mm vs. 0.5 mm), and longer mean hospital stay (4.9 d vs. 4.5 d) were observed in the anterior full-endoscopic cervical discectomy group. Postoperatively, the clinical outcomes of the 2 approaches were significantly improved, but the differences between the 2 approaches were not significant (P = 0.211 and P = 0.257, respectively). Four surgery-related complications were observed among all enrolled patients (complications in each group were 2; overall 4 of 84, 4.8%).

CONCLUSION

In our study, the clinical outcomes between the 2 approaches did not differ significantly. Nevertheless, posterior full-endoscopic cervical discectomy may be preferable when considering the volume of disc removal, length of hospital stay, and the postoperative radiographical changes. As an efficacious supplement to traditional open surgery, FECD is a reliable alternative treatment of CIVDH and its optimal approach remains open to discussion.

LEVEL OF EVIDENCE

3.

Retrospective evaluation of efficiency and safety of an anterior percutaneous approach for cervical discectomy

Study Design

Retrospective case series.

Purpose

The purpose of the study was to evaluate the efficiency and complication rate of a percutaneous anterior approach to herniated cervical disks with or without concomitant foraminal stenosis and/or spondylosis.

Overview of Literature

Recent publications reflect that minimally invasive procedures gain in importance in patients and spine surgeons as they are generally associated with less tissue damage and shorter recovery times. However, for anterior percutaneous cervical discectomy, very little data is available for relevant patient populations.

Methods

Charts from patients with herniated cervical disc confirmed by magnetic resonance imaging, mainly radicular symptoms and irresponsive to conservative treatment who underwent anterior percutaneous discectomy were evaluated retrospectively. All patients were asked to return questionnaires that included visual analogue scores (VAS), MacNab score as well as subjective satisfaction data 2 years after surgery.

Results

Ninety-five patients were included. There were no neurological or vascular complications; only one patient suffered from transient hoarseness. During the two years after surgery, 9 patients underwent reoperation. 90.5% of the patients returned the questionnaire at 2 years' follow-up. 87.7% of them reported excellent or good outcome, 11.1% rated results as fair and 1.2% as unsatisfactory. On average, arm and neck pain improved significantly by 6.1 points and 5.8 points respectively on a ten point VAS. 94.5% stated that they would choose the same procedure again.

Conclusions

This procedure has proved a safe and sufficient option for symptomatic cervical disk herniations with or without concomitant spondylosis and/or foraminal stenosis.

Treatment of cervical disc herniation through percutaneous minimally invasive techniques

PURPOSE

The goal of this study is to compare the therapeutic effectiveness of percutaneous cervical discectomy, percutaneous cervical disc nucleoplasty, and a combination of the two for the treatment of cervical disc herniation and the effective stabilization of the cervical vertebral column.

METHODS

A retrospective study was performed from February 2003 to April 2011. One hundred and seventy-one cervical disc herniation patients with a mean age of 47.8 years (ranging from 21 to 74 years) participated in the study and were treated with the three types of percutaneous minimally invasive techniques: percutaneous cervical discectomy (PCD, 97 cases), percutaneous cervical disc nucleoplasty (PCN, 50 cases), and a combination of the two (PCDN, 24 cases). After treatment, the postoperative clinical results and the stability of the cervical vertebral columns of these three groups were evaluated and compared.

RESULTS

Patients in the PCD group received follow-up care for approximately 4.1 years (ranging from 0.2 to 8.5 years), while those in the PCN group received only an average of 2.6 years (ranging from 0.3 to 7.8 years), and the PCDN group received an average of 3.3 years (ranging from 0.2 to 8 years of follow-up). According to the Japanese Orthopedic Association scoring system, the functional scores (JOA scores) differed significantly between the pre- and postoperative patients within the three groups (PCD t = 21.849, P = <0.05; PCN t = 14.503, P < 0.05; PCDN t = 8.555, P < 0.05). All patients had been successfully operated on by the same spinal surgeon team. According to the Odom criterion, the clinical outcomes were not significantly different for any of the three groups (the recovery rate using the JOA standard evaluation, F = 2.19, P = 0.116, P > 0.05). The percentages of each procedure that received either an excellent or a good rating were PCD at 81.35 %, PCN at 82.44 % and PCDN at 83.19 %. In addition, the clinical success rates among the three were not significantly different (P > 0.05). Notably, there was no postoperative instability of the cervical vertebral column in any of the patients (P > 0.05), and there was no difference in the pre- or postoperative stability of the cervical vertebral columns in each group.

CONCLUSIONS

Each group achieved good clinical outcomes with this safe, minimally invasive spinal surgery for the treatment of cervical disc herniation. In addition, no postoperative risk of cervical instability was found.

Percutaneous endoscopic cervical discectomy: 16 years of experience and literature review

The advancement of the percutaneous endoscopic lumbar discectomy (PECD) and its clinical success have led to similar minimally invasive approaches to the cervical spine. The goal of PECD is the decompression of the cervical nerve root through a direct endoscopic visualization, removing the herniated mass and shrinking the nucleous pulposus with the use of microforceps and holmium: yttrium-aluminum-garnet (Ho:YAG) laser. The senior author have performed PECD with cervical laser assisted endoscopy since 1993. The PECD is indicate to patients with constrained or unconstrained soft herniated cervical disc, positive provocative test, and no bony spur larger than 2 mm, regardless of the herniation size. The authors described the surgical technique of PECD and report their 16 years of experience in the endoscopic treatment of the herniated cervical disc.

Early outcome of posterior cervical endoscopic discectomy: an alternative treatment choice for physically/socially active patients

Anterior cervical discectomy and fusion (ACDF) is currently the standard treatment for cervical disc disease. Some patients wish to be treated with a less invasive method, because of their social/physical situations. Here we present one method of treatments for socially/physically active patients. Three patients had triceps weakness and mild posterior neck pain. The offending lesions were at the C6-7 level. All were middle-aged soldiers with families. If conventional ACDF were performed, they would have to retire from the military according to the regulation. They had to be able to perform military drills after the treatment if they were going to be able to keep their jobs. Because of their social/physical situations, all wanted to choose method with that they could treat the disease and keep their jobs. For these reasons, the posterior cervical endoscopic discectomies were performed. Ruptured fragments were successfully removed in all. The arm pain improved by more than 90% in two patients by 7 days and in the other patient by 2 months, respectively (excellent outcome by Macnab's criteria). None of the operations caused instability. All of the patients are currently able to successfully perform their military drills without difficulty. The posterior cervical endoscopic discectomy may be a promising alternative for the physically/socially active patients.

The safety zone of percutaneous cervical approach: a dynamic computed tomographic study

STUDY DESIGN

A prospective study using computed tomography (CT) scans.

OBJECTIVE

To identify the structures at risk and the safety zone of a percutaneous cervical approach.

SUMMARY OF BACKGROUND DATA

A percutaneous cervical approach may injure the important structures of the anterior neck. However, the dynamic locations of vital structures and the structures at risk by routine trajectory have not been analyzed.

METHODS

Thirty patients were enrolled for this study. We obtained the CT scans of the cervical spine at each level of the intervertebral disc from C3-C4 to C6-C7, after manually pushing the airway in the same position and manner of discography. The patients ingested contrast materials for imaging of their digestive tracts and were injected intravenous contrast materials for imaging of vascular structures, just before obtaining images. We estimated the distances from the operator's fingertip to the digestive tract on the left side and to the carotid artery on the right side, at each level. The safety zone was determined by the sum of 2 distance calculations. We identified the anatomic structure at risk by simulated needle insertion toward the center of the disc through the safety zone.

RESULTS

At C3-C4, the safety zone was measured 18.9 +/- 6.6 mm. The superior thyroidal artery (STA) was located in the safety zone of C3-C4 in 86.7%. At C4-C5, the safety zone was measured 23.5 +/- 6.5 mm. The STA and the right lobe of the thyroid gland (TG) were located in the safety zone in 26.7% and 30%, respectively. At C5-C6, the safety zone was measured 33.7 +/- 6 mm. The TG was located in the safety zone of C5-C6 in 76.7%. At C6-C7, the safety zone was 29.2 +/- 4.5 mm. The TG was located on the approach plane in 90%.

CONCLUSION

The safety zone was wider at the distal level (C5-C6, C6-C7) than at the proximal level (C3-C4, C4-C5). The safest needle entry point should be between the pushing point of the airway and the pulsating point of the carotid artery. In addition, the needle should be approached toward the center of the disc. A percutaneous cervical approach allows a low risk of pharyngoesophageal structure injury and is considered a safe diagnostic technique in dynamic imaging studies.

Imaging the degenerative diseases of the lumbar spine

Degenerative changes of the spine may involve the disc space, the facet joints, or the supportive and surrounding soft tissues. MR imaging is ideally suited for delineating the presence, extent, and complications of degenerative spinal disease. Other imaging modalities such as radiography, myelography, and CT may provide complimentary information in selected cases. Percutaneous procedures may be used to confirm that a morphologic abnormality is the source of symptoms. Correlation with clinical and electrophysiologic data is also helpful for accurate diagnosis. Combining the information obtained from imaging studies with the patient's clinical presentation is mandatory for determining the appropriate patient management strategy, especially true in patients afflicted with any condition directly attributed to the degenerative processes of the spine.

Anterior minimally invasive approaches for the cervical spine

The percutaneous endoscopic discectomy (PECD) with working channel endoscope (WSH) endoscopy set could be a safe and effective minimally invasive surgical option for non-contained cervical disc herniation in selected patients. Judicious use of the end-firing Ho: Yttrium-Aluminium-Garnet (YAG) laser for both decompressive and thermoannuloplasty effect during the percutaneous endoscopic cervical annuloplasty (PECA) is mandatory in order to prevent possible injury to spinal cord or root. Although the percutaneous cervical stabilization (PCS) using the cervical B-Twin may not completely replace the cervical arthrodesis, this minimally invasive procedure can preserve anterior structures and thereby retain segmental stability and prevent the possible kyphotic progression after fusion surgery. To our knowledge, these minimally invasive procedures for cervical spine disease may serve to minimize surgery-induced complications associated with anterior cervical discectomy and fusion (ACDF).

Immediate Pain Improvement Is a Useful Predictor of Long-Term Favorable Outcome after Percutaneous Laser Disc Decompression for Cervical Disc Herniation

OBJECTIVE

The purpose of this study was to evaluate the long-term clinical outcome of percutaneous laser disc decompression (PLDD) for cervical disc herniation and to identify factors affecting long-term favorable outcome.

BACKGROUND DATA

PLDD using the Ho:YAG laser has been regarded as an effective alternative for soft disc herniation. However, little is known about long-term favorable outcome parameters.

METHODS

We retrospectively reviewed the clinical and radiological data of 60 patients who underwent PLDD with laser-assisted spinal endoscopy (LASE) for contained cervical soft disc herniation from January 1998 to January 2000. The clinical outcome was measured using the Macnab criteria. Statistical analysis was performed using Fisher's exact test. Sex, age, operated level and location of disc herniation, amount of laser energy, and time for symptom improvement were selected as parameters.

RESULTS

The mean follow-up period was 71.0 months (range, 59-83 months). The mean age was 45.7 years (range, 26-68 years), and the mean symptom duration was 13.0 months (range, 2-60 months). The Visual Analogue Scale (VAS) score was significantly improved from 7.9 preoperatively to 2.6 at the final follow-up (p < 0.001). At the final follow-up, 51 (85.0%) patients achieved a favorable outcome. Immediate (within 24 h) pain relief was achieved in 19 patients, and it was strongly related to long-term success (p = 0.006).

CONCLUSION

The long-term clinical outcome of PLDD with LASE was fairly good, with a success rate of 85%. Immediate pain relief is a useful prognostic factor predicting favorable outcome following the procedure.

Percutaneous endoscopic cervical discectomy: clinical outcome and radiographic changes

OBJECTIVE

The purpose of this study was to evaluate the clinical outcome and radiographic changes of percutaneous endoscopic cervical discectomy (PECD) with the high-resolution working channel endoscope.

BACKGROUND DATA

Percutaneous disc decompression using a laser and/or microforceps for cervical disc herniation has been regarded as an effective treatment modality in selected cases. However, the postoperative radiographic changes have not yet been evaluated.

METHODS

We reviewed the clinical and radiographic records of 36 consecutive patients who underwent PECD with the working channel endoscope. The herniated discs were selectively removed by Ho:YAG laser and microforceps under high-resolution endoscopic visualization. The postoperative radiographic changes, including the disc height, the sagittal cervical alignment, and the segmental range of motion were measured.

RESULTS

The mean follow-up period was 28.6 months (range, 23-34 months). Based on the Prolo Scale, excellent outcomes were achieved in 19 of 36 patients (52.8%), good outcomes in 12 (33.3%), fair outcomes in three (8.3%), and poor outcomes in two (5.6%). The disc height significantly decreased by 11.2% of the original height (p < 0.001). However, the overall and focal sagittal alignments were well maintained. There was no segmental instability or spontaneous fusion. One patient required subsequent open surgery due to incomplete decompression.

CONCLUSIONS

The high-resolution working channel endoscope allowed us to selectively remove the cervical herniated disc. The postoperative disc height reduction was observed, with no significant effect on therapeutic success. The sagittal alignment and segmental motion were well preserved.

Percutaneous endoscopic cervical discectomy for discogenic cervical headache due to soft disc herniation

A discogenic cervical headache is a subtype of cervicogenic headache (CEH) that arises from a degenerative cervical disc abnormality. The purpose of this study was to evaluate the clinical outcome of percutaneous endoscopic cervical discectomy (PECD) for patients with chronic cervical headache due to soft cervical disc herniation. Seventeen patients underwent PECD for intractable headache. The inclusion criteria were soft disc herniation without segmental instability, proven by both local anesthesia and provocative discography for headache unresponsive to conservative treatment. The mean follow-up period was 37.6 months. Fifteen of the 17 patients (88.2%) showed successful outcomes based on the Macnab criteria. Pain scores on a visual analog scale (VAS) improved from a preoperative mean of 8.35 +/- 0.79 to 2.12 +/- 1.17, postoperatively (P < 0.01). The mean disc height decreased from 6.81 +/- 1.08 to 5.98 +/- 1.07 mm (P < 0.01). There was no newly developed segmental instability or spontaneous fusion on follow-up radiography. In conclusion, PECD appears to be effective for chronic severe discogenic cervical headache under strict inclusion criteria.