Effective Range of Percutaneous Posterior Full-Endoscopic Paramedian Cervical Disc Herniation Discectomy and Indications for Patient Selection

Magnetic Resonance Imaging Documentation of Approach Trauma With Lumbar Endoscopic Interlaminar, Translaminar, Compared to Open Microsurgical Discectomy

BACKGROUND

Endoscopic spine surgery is associated with less approach trauma than conventional open translaminar surgery. However, objective evidence to corroborate this empiric observation is scarce. Preservation of the anatomic attachment and sensory function of multifidus muscles have been stipulated to be critical to maintaining the normal function of the lumbar spinal motion segment. The authors were interested in comparing the postoperative approach trauma between traditional open translaminar microsurgical and interlaminar endoscopic discectomy.

METHODS

The approach trauma to the paraspinal muscles due to interlaminar or open microsurgical discectomy was evaluated on T2-weighted axial magnetic resonance imaging (MRI) images of 39 consecutive patients who underwent lumbar disc surgery. Postoperative MRI images taken at 4 days and within 1 year after surgery were analyzed. Eleven patients underwent conventional open translaminar microdiscectomy surgery. Endoscopic discectomy was performed on 17 patients via the interlaminar and on another 11 patients via the transforaminal approach. The immediate surgical approach trauma was estimated as the defect zone by measuring the normalized relative cross-sectional area (rCSA) of muscle disruption in the surgical corridor 4 days postoperatively. The long-term effect of surgical approach trauma was assessed by measuring the area of the paraspinal muscles that had been replaced by fatty tissue 1 year postoperatively.

RESULTS

The rCSA data showed diminished approach trauma with a smaller surgical defect zone in the interlaminar endoscopy group (17.6%) was smaller than in the microsurgical group 4 days postoperatively (41.2%). At 1 year postoperatively, the mean fatty replacement of the paraspinal muscles was 23.6% after microsurgery and 2.1% after the interlaminar endoscopy. Muscle recovery was substantially reduced in the interlaminar endoscopic group, with the muscle zone reducing from 20.3% to 2.1% when analyzed 1 year postoperatively. In the microsurgery group, the muscle damage by atrophy increased from 41.2% to 62.9% at 1 year postoperatively (P < 0.001). Fatty replacement of the multifidus muscle was seen on the ipsilateral and contralateral approach side. There was a negligible change in the muscle zone with the transforaminal approach.

CONCLUSIONS

Tissue trauma was significantly reduced with endoscopic surgery techniques compared with the traditional translaminar microdiscectomy approach. There was a minor postoperative tissue trauma and hardly any long-term replacement of the multifidus and paraspinal muscles by fatty tissue 1 year postoperatively with the endoscopic technique. The transforaminal approach has the least effect on the paraspinal muscles of the surgical motion segment. Further study is needed to investigate whether these findings translate into decreased postoperative instability or low back pain following endoscopic discectomy surgery.

CLINICAL RELEVANCE

MRI analysis of multifidus atrophy following various lumbar translaminar and transforaminal decompression techniques.

LEVEL OF EVIDENCE: 3

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.

Dural Tears During Lumbar Spinal Endoscopy: Surgeon Skill, Training, Incidence, Risk Factors, and Management

BACKGROUND

Incidental dural tears during lumbar endoscopy can be challenging to manage. There is limited literature on their appropriate management, risk factors, and the clinical consequences of this typically uncommon complication.

MATERIALS AND METHODS

To improve the statistical power of studying durotomy with lumbar endoscopy, we performed a retrospective survey study among endoscopic spine surgeons by email and chat groups on social media networks, including WhatsApp and WeChat. Descriptive and correlative statistics were done on the surgeons' recorded responses to multiple-choice questions. Surgeons were asked about their clinical experience with spinal endoscopy, training background, the types of lumbar endoscopic decompression they perform by approach, the decompression instruments they use, and incidental durotomy incidence with routine lumbar endoscopy.

RESULTS

There were 689 dural tears in 64 470 lumbar endoscopies, resulting in an incidental durotomy incidence of 1.07%. Seventy percent of the durotomies were reported by 20.4% of the surgeons. Eliminating these 19 outlier surgeons yielded an adjusted durotomy rate of 0.32. Endoscopic stenosis decompression (54.8%; P < .0001), rather than endoscopic discectomy (44.1%; 41/93), was significantly more associated with durotomy. Medium-sized dural tears (1-10 mm) were the most common (52.2%; 48/93). Small pinhole durotomies (less than 1 mm) were the second most common type (46.7%; 43/93). Rootlet herniations were seen by 46.2% (43/93) of responding surgeons. The posterior dural sac injury during the interlaminar approach (57%; 53/93) occurred more frequently than traversing nerve-root injuries (31.2%) or anterior dural sac (23.7%; 22/93). Exiting nerve-root injuries (10.8%;10/93) were less common. Over half of surgeons did not attempt any repair or closure (52.2%; 47/90). Forty percent (36/90) used sealants. Only 7.8% (7/90) of surgeons attempted an endoscopic repair or sutures (11.1%; 10/90). DuralSeal was the most commonly used brand of commercially available sealant used (42.7%; 35/82). However, other sealants such as Tisseal (15.9%; 13/82), Evicel (2.4%2/82), and additional no-brand sealants (38; 32/82) were also used. Nearly half of the patients (48.3%; 43/89) were treated with 24-48 hours of bed rest. The majority of participating surgeons (64%; 57/89) reported that the long-term outcome was unaffected. Only 18% of surgeons reported having seen the development of a postoperative cerebrospinal fluid (CSF)-fistula (18%;16/89). However, the absolute incidence of CSF fistula was only 0.025% (16/64 470). Severe radiculopathy with dysesthesia; sensory loss; and motor weakness in association with an incidental durotomy were reported by 12.4% (11/89), 3.4% (3/89), and 2.2% (2/89) of surgeons, respectively.

CONCLUSIONS

The incidence of dural tears with lumbar endoscopy is about 1%. The incidence of durotomy is higher with the use of power drills and the interlaminar approach. Stenosis decompression that typically requires the more aggressive use of these power instruments has a slightly higher incidence of dural tears than does endoscopic decompression for a herniated disc. Most dural tears are small and can be successfully managed with mechanical compression with Gelfoam and sealants. Two-thirds of patients with incidental dural tears had an entirely uneventful postoperative course. The remaining one-third of patients may develop a persistent CSF leak, radiculopathy with dysesthesia, sensory loss, or motor function loss. Patients should be educated preoperatively and reassured.

LEVEL OF EVIDENCE

3.

Design of a robot-assisted system for transforaminal percutaneous endoscopic lumbar surgeries: study protocol

Background

Transforaminal percutaneous endoscopic lumbar surgeries (PELS) for lumbar disc herniation and spinal stenosis are growing in popularity. However, there are some problems in the establishment of the working channel and foraminoplasty such as nerve and blood vessel injuries, more radiation exposure, and steeper learning curve. Rapid technological advancements have allowed robotic technology to assist surgeons in improving the accuracy and safety of surgeries. Therefore, the purpose of this study is to develop a robot-assisted system for transforaminal PELS, which can provide navigation and foraminoplasty.

Methods

The robot-assisted system consists of three systems: preoperative planning system, navigation system, and foraminoplasty system. In the preoperative planning system, 3D visualization of the surgical segment and surrounding tissues are realized using the multimodal image fusion technique of computed tomography and magnetic resonance imaging, and the working channel planning is carried out to reduce the risk for injury to vital blood vessels and nerves. In the navigation system, the robot can obtain visual perception ability from a visual receptor and automatically adjust the robotic platform and robot arm to the appropriate positions according to the patient’s position and preoperative plan. In addition, the robot can automatically register the surgical levels through intraoperative fluoroscopy. After that, the robot will provide navigation using the 6 degree-of-freedom (DOF) robot arm according to the preoperative planning system and guide the surgeon to complete the establishment of the working channel. In the foraminoplasty system, according to the foraminoplasty planning in the preoperative planning system, the robot performs foraminoplasty automatically using the high speed burr at the end of the robot arm. The system can provide real-time feedback on the working status of the bur through multi-mode sensors such as multidimensional force, position, and acceleration. Finally, a prototype of the system is constructed and performance tests are conducted.

Discussion

Our study will develop a robot-assisted system to perform transforaminal PELS, and this robot-assisted system can also be used for other percutaneous endoscopic spinal surgeries such as interlaminar PELS and percutaneous endoscopic cervical and thoracic surgeries through further research. The development of this robot-assisted system can be of great significance. First, the robot can improve the accuracy and efficiency of endoscopic spinal surgeries. In addition, it can avoid multiple intraoperative fluoroscopies, minimize exposure to both patients and the surgical staff, shorten the operative time, and improve the learning curve of beginners, which is beneficial to the popularization of percutaneous endoscopic spinal surgeries.

Analysis of compliance and efficacy of integrated management of whole process in the choice of percutaneous full-endoscopic surgery for patients with cervical disc herniation

Background

Percutaneous spinal endoscopy is a new type of surgery for the treatment of cervical disc herniation. It can avoid the complications of the classic anterior cervical discectomy and fusion (ACDF) approach and the risk of adjacent spondylosis. How can we effectively improve patients’ awareness of spinal endoscopy and their election of endoscopic techniques?

Objective

To analyze the compliance and clinical effect of the integrated management of the whole process in the choice of percutaneous full-endoscopic surgery for patients with cervical disc herniation.

Methods

Retrospective analysis of 72 patients with cervical disc herniation undergoing surgery in our hospital from August 2015–August 2017 was performed. The whole-process integrated management model was used for all the patients. The 36 patients in the experimental group were treated by percutaneous full-endoscopic cervical discectomy, and the 36 patients in the control group were treated by ACDF. The postoperative feeding time, time to get out of bed, length of hospital stay, compliance, clinical efficacy, and recurrence rate of neck pain were observed. Changes between the preoperative and postoperative pain visual analog scale (VAS) scores and neurological function Japan Orthopaedic Association (JOA) scores were assessed.

Results

The postoperative feeding time in the experimental group was 8.319 ± 1.374 h, the postoperative time to get out of bed was 16.64 ± 3.728 h, and the hospitalization time was 6.403 ± 0.735 days. The excellent and good clinical efficacy rate was 91.67%, the compliance rate was 88.89%, and the neck pain recurrence rate was 5.56%. The postoperative feeding time in the control group was 26.56 ± 9.512 h, the postoperative time to get out of bed was 45.06 ± 9.027 h, and the length of hospital stay was 8.208 ± 0.865 days. The excellent and good clinical efficacy rate was 88.89%, the compliance rate was 69.4%, and the neck pain recurrence rate was 8.33%. There was no significant difference between the two groups in the excellent efficacy rate and the neck pain recurrence rate, p > 0.05. The compliance rate in the experimental group was better than that in the control group, and the difference was statistically significant, p < 0.05. The hospitalization time of the experimental group was significantly lower than that of the control group, and the difference was statistically significant, p < 0.05. The postoperative VAS scores and JOA scores of the two groups were significantly better than the preoperative scores, and the difference was statistically significant, p < 0.05; there was no significant difference between the two groups, p > 0.05.

Conclusion

The integrated management of the whole course can effectively improve the compliance of patients with cervical disc herniation receiving endoscopic treatment, yield the same treatment effect as the classic operation, shorten the hospitalization time, speed up the turnover of hospital beds, and improve satisfaction with medical quality and is worthy of clinical application.

Trans-interlamina percutaneous endoscopic cervical discectomy for symptomatic cervical spondylotic radiculopathy using the new Delta system

To describe the rationale and surgical technique and compare the clinical effect of posterior percutaneous endoscopic cervical discectomy (PPECD) using the Delta system versus that of conventional PPECD (key-hole) surgery for the treatment of symptomatic cervical spondylotic radiculopathy (CSR). A retrospective analysis was performed on 106 single-segment CSR patients between February 2016 and February 2017, 50 of whom underwent conventional PPECD (key-hole), and 56 underwent PPECD using the Delta system. The operative time, intraoperative blood loss, intraoperative complications and postoperative hospital stay were recorded, and the clinical effect was evaluated by the indicators of the Neck Disability Index (NDI), arm-visual analog scale (arm-VAS), neck-VAS, EQ-5D and MacNab classification at the last follow-up. All patients underwent the operation successfully, and 106 patients were followed up. The operative time of the Delta group was 60.47 ± 0.71 min, while the operative time of the key-hole group was 75.46 ± 0.41 min. The difference between the two groups was statistically significant (P < 0.05). However, there was no significant difference between the two groups in terms of blood loss and hospital stay (P > 0.05). The VAS, NDI and EQ-5D scores of the neck and upper limbs in the two groups were significantly better than those before surgery at 1 week after surgery and at the last follow-up (P < 0.05). However, there was no significant difference between the two groups at the last follow-up (P > 0.05). At the last follow-up, there was no significant difference between the two surgical methods when evaluated using the modified MacNab criteria. The imaging results showed that the herniated disc was removed completely and the nerve root was decompressed. The complication rate in the Delta group (3/56, 5.35%) was significantly lower than that in the conventional key-hole group (5/50, 10.0%). PPECD using the Delta system for CSR may be a feasible and promising alternative surgical plan. Compared with the traditional key-hole method, this surgical system can not only provide the surgeon with a larger surgical field of vision but also reduces the operation time and complication rates.

Treatment of cervical spondylotic radiculopathy with posterior percutaneous endoscopic cervical discectomy: Short-term outcomes of 24 cases

To determine the short-term clinical outcomes of single-segment cervical spondylotic radiculopathy treated with posterior percutaneous endoscopic cervical discectomy (PPECD).Data of a total of 24 patients who underwent PPECD and local anesthesia for single-level segmental cervical spondylotic radiculopathy between March 2016 and December 2017 were reviewed. The Japanese Orthopaedic Association, visual analog scale (VAS), and neck disability index scores at preoperative 1 day, postoperative 1 day, 1 week, 1 month, 3 months, 6 months, and 1 year were recorded. The modified MacNab criteria at the last follow-up were re-recorded for the evaluation of clinical effectiveness.All operations were successfully completed under endoscopic guidance. No patient showed spinal cord, nerve root, vascular injuries, dural tears or other complications. The postoperative VAS scores of the arm and neck were significantly reduced compared with the preoperative VAS scores (P < .05), while postoperative the Japanese Orthopaedic Association scores were significantly increased (P < .05). The postoperative neck disability index scores were significantly reduced compared with preoperative scores (P < .05). The modified MacNab criteria at the last follow-up showed 16 excellent cases, 8 good cases, 0 fine cases, and 0 poor cases. Postoperative magnetic resonance imaging and cervical 3-dimensional computed tomography reconstruction showed that the intervertebral disc was adequately resected and the nerve root was not under compression.PPECD is safe and effective for the treatment of single-segment cervical spondylotic radiculopathy.

Selective nerve root block combined with posterior percutaneous cervical endoscopic discectomy for cervical spondylotic radiculopathy with double nerve root variation: A case report

RATIONALE

The aim of this report is to present the technique of selective nerve root blockage combined with posterior percutaneous cervical endoscopic discectomy (PPECD) for cervical spondylotic radiculopathy (CSR).

PATIENT CONCERNS

A 49-year-old female has pain in the skin area of the left scapular, pain in left elbow and limitation of left upper limb movement for 1.5 years.

DIAGNOSIS

She was diagnosed with CSR and C6-7 double nerve root variation.

INTERVENTIONS

We used selective nerve root block to determine the lesion segment and applied PPECD to relieve pressure on the patient's nerve roots.

OUTCOMES

The pain symptoms disappeared after the patient was treated with C6-7 nerve root block. Endoscopic displayed C6-7 double nerve root variation on the left side of the spinal cord intraoperative. The neurological function was intact postoperatively and no recurrence of cervical disc herniation during the 5 months' follow-up period. The hospitalization time was 5 days, the operation time was 68.2 minutes and the bleeding volume was 52.6 ml. There was no change in cervical curvature and cervical disc height postoperatively. Japanese Orthopaedic Association score, SF-36 score and Visual Analogue Scale score improved significantly postoperatively.

LESSONS

The application of selective nerve root blockage combined with PPECD for CSR could achieve satisfactory effect of position and decompression of the injured nerve root. Besides, we recommend that surgery be performed under general anesthesia to minimize patients' emotional stress and discomfort.

Full Endoscopic Key Hole Technique for Cervical Foraminal Stenosis: Is Mere Dorsal Decompression Enough?

OBJECTIVE

To study whether and when mere dorsal decompression is enough in the full endoscopic key hole technique for foraminal stenosis.

METHODS

We retrospectively reviewed a total of 22 patients with cervical foraminal stenosis who underwent full endoscopic key hole mere dorsal decompression in our institute from October 2016 to October 2017.

RESULTS

Preoperative neck disability index, neck visual analog scale score, and arm visual analog scale score were 25.8 ± 0.8, 4.9 ± 0.6, and 7.5 ± 0.5 in the group. Immediate postoperative scores were 6.9 ± 0.9, 1.3 ± 0.9, and 1.4 ± 0.5. Follow-up scores at 3 months (7.0 ± 0.9, 1.9 ± 0.6, and 2.7 ± 0.9), 6 months (7.3 ± 0.9, 2.1 ± 0.9, and 1.9 ± 0.5), and 12 months (7.6 ± 0.5, 2.5 ± 0.8, and 2.1 ± 0.7). The symptoms had improved significantly (P < 0.05). According to the Macnab criteria, 15 patients reported excellent results, 2 reported good results, and 2 reported fair results at the 12-month follow-up.

CONCLUSIONS

Stenosis is mainly caused by dorsal structures; mere dorsal decompression is enough. In both cases, the ventral and dorsal structures contributed to the stenosis. When there is no herniated soft fragment contributing to the stenosis, ventral decompression is not always necessary. If intraoperative exploration detects less tension formed by the ventral abnormal structures, mere dorsal decompression is enough to settle the symptoms.

Endoscopic Anterior Approach for Cervical Disc Disease (Disc Preserving Surgery)

OBJECTIVE

To report our experience of endoscopic disc removal by anterior approach for management of cervical myelopathy in 210 patients.

METHODS

A retrospective study of 187 cases of single- and 23 cases of double-level disc disease was performed. Cases of myelopathy with or without unilateral or bilateral radiculopathy and unilateral radiculopathy with either soft or hard disc prolapse were included. Patients with ≥3 disc levels, unstable spine, infections, trauma, significant posterior compression, congenital canal stenosis, disc extending more than half the vertebral body height, and prior surgery at the same level were excluded.

RESULTS

C5-6 (n = 119 patients), C6-7 (n = 58 patients), C4-5 (n = 49 patients), C3-4 (n = 6 patients), and C2-3 (n = 1 patient) levels were represented. Visual analog scale and Nurick grading system were used to assess severity of neck and arm pain and functional outcomes, respectively. Preoperative mean visual analog scale scores for arm and neck pain were 6.7 and 3.2, respectively, which improved to 1.7 and 1.1 at 3 months after surgery. The average preoperative Nurick grade improved from 2.64 to 0.81 at 6 months postoperatively. Follow-up was 6-54 months.

CONCLUSIONS

Endoscopic anterior discectomy (disc preserving surgery) is an effective and safe alternative in cervical disc disease. Although there was reduction in disc height, clinical outcome was good at an average 29 months of follow-up. Long-term follow-up is required to assess any progressive disc degeneration and clinical results.