Percutaneous endoscopic lumbar foraminotomy: an advanced surgical technique and clinical outcomes

Facet Sparing Foraminal Decompression Using the Flexible Shaver Foraminotomy System: Nerve Safety, Pain Relief, and Patient Satisfaction

Background

A number of surgical options exist for decompressing lumbar foraminal stenosis. Flexible shaver foraminotomy is a recent addition to this armamentarium. While the foraminotomy device has been incorporated into clinical practice, the literature on its safety and efficacy remain limited. We aimed to evaluate nerve safety, pain relief, and patient satisfaction in a series of patients treated with the iO-Flex shaver system (Amendia, Inc., Marietta, Georgia).

Methods

Thirty-one consecutive patients with lumbar foraminal stenosis underwent foraminal decompression using the flexible microblade shaver system at 62 neuroforamina. The shavers were inserted into each foramen using an open hemilaminotomy and fluoroscopic guidance. Nerve mapping via mechanomyography (MMG) was used to ensure nerve safety. Perioperative charts were reviewed to find the incidence of neurologic complications and to quantify pain relief. Average office-based follow-up was 5.3 months. A 3-item questionnaire was administered to assess patient satisfaction during late follow-up, which occurred at an average of 21 months.

Results

No planned iO-Flex foraminotomies were aborted. Neurologic complications included transient dysesthetic pain in 1 patient (3.2%, n = 31), and transient numbness in 3 patients (9.7%, n = 31). There were no motor deficits. The composite nerve complication rate was 12.7%. Preoperative visual analog scale scores decreased from a mean of 7.1 (n = 31, standard deviation [SD] 2.0) to a mean of 3.5 (n = 30, SD 2.5). If asked to repeat their decision to do surgery, 81% of patients would redo the procedure. The rate of patient dissatisfaction was 19%.

Conclusions

Decompression of lumbar foramina using the flexible shaver system and MMG nerve mapping is safe and effective, although the short-term sensory complication with this technique may be higher than previously reported. Patient satisfaction with iO-Flex foraminotomy is comparable to reported satisfaction outcomes for traditional lumbar decompression.

Level of Evidence

4.

Laser-Assisted Microdiscectomy for Far Lateral Lumbar Disc Herniation at the L5-S1 Level

OBJECTIVE

Laser-assisted paraspinal microdiscectomy for far lateral lumbar disc herniation (LDH) enables direct access to the foraminal or far lateral zone with minimal tissue injury and preserves facet joints, thereby preventing postoperative segmental instability. We demonstrated the clinical outcomes of this technique and discussed the pros and cons of laser use in lumbar disc surgery.

BACKGROUND

The microdiscectomy technique for L5-S1 far lateral zone may be difficult due to the limited surgical field with narrowed disc space, hypertrophied facet, and sacral ala. Thus, we used carbon dioxide (CO₂) laser for sophisticated decompression.

METHODS

Eighty-four patients who were treated with microdiscectomy for far lateral LDH at the L5-S1 level were evaluated. Among them, 40 patients were treated using CO₂ laser-assisted microdiscectomy, and the remaining 44 patients using conventional microdiscectomy. Perioperative and postoperative data were compared between the two groups with 2 years of follow-up. Clinical outcomes were assessed using the visual analog scale (VAS), Oswestry disability index (ODI), and modified Macnab criteria.

RESULTS

VAS and ODI significantly improved in both groups. An excellent or good outcome was rated in 80% and 77.3% of the laser and conventional group, respectively. There was no significant difference in global outcomes. However, hospital stay and time to return to work were significantly shorter in the laser group (p < 0.05).

CONCLUSIONS

CO₂ laser-assisted paraspinal microdiscectomy is effective for treating far lateral LDH. The pinpoint laser scalpel enables delicate and complete decompression in a limited surgical field with minimal tissue trauma.

Delayed Infected Pseudomeningocele After Percutaneous Endoscopic Lumbar Diskectomy

BACKGROUND

Percutaneous endoscopic lumbar diskectomy (PELD) has evolved over the last decades and has become an effective treatment for soft disk herniations. However, while its use increases, newer complications have been discovered.

CASE DESCRIPTION

We present the unique case of a woman who underwent PELD/foraminotomy to treat right-side foraminal disk herniations on L4-5 and L5-S1 in the same procedure. Ten days after surgery, the patient developed fever and severe low back pain radiated down her right leg. Magnetic resonance imaging showed a right pseudomeningocele arising from L4-5 and a nerve root herniated through the dural sac at the same lumbar segment. Blood cultures and fluid culture obtained from pseudomeningocele drainage depicted infection. Specific antibiotics were administrated, direct dura repair under the microscope was performed, and the patient improved symptomatically.

CONCLUSIONS

PELD combined with foraminotomy is a relatively new and skill-demanding surgery which is indicated only in cases where foraminal disk herniation is combined with foraminal stenosis. This surgical strategy requires experience by the endoscopic surgeon to prevent procedure-related complications. Although rare, these complications can lead to increased morbidity.

Extraforaminal approach of biportal endoscopic spinal surgery: a new endoscopic technique for transforaminal decompression and discectomy

This study was performed to describe the extraforaminal approach of biportal endoscopic spinal surgery (BESS) as a new endoscopic technique for transforaminal decompression and discectomy and to demonstrate the clinical outcomes of this new procedure for the first time. Twenty-one patients (27 segments) who underwent the extraforaminal approach of BESS between March 2015 and April 2016 were enrolled according to the inclusion and exclusion criteria. The operative time (minutes/level) and complications after the procedure were recorded. The visual analog scale (VAS) score was checked to assess the degree of radicular leg pain preoperatively and at the time of the last follow-up. The modified Macnab criteria were used to examine the clinical outcomes at the time of the last follow-up. The mean duration of the follow-up period was 14.8 months (minimum duration 12 months). The mean operative time was 96.7 minutes for one level. The mean VAS score for radicular leg pain dropped from a preoperative score of 7.5 ± 0.9 to a final follow-up score of 2.5 ± 1.2 (p < 0.001). The final outcome according to the modified Macnab criteria was excellent in 5 patients (23.8%), good in 12 (57.2%), fair in 4 (19.0%), and poor in 0. Therefore, excellent or good results (a satisfied outcome) were obtained in 80.9% of the patients. Complications were limited to one dural tear (4.8%). The authors found that the extraforaminal approach of BESS was a feasible and advantageous endoscopic technique for the treatment of foraminal lesions, including stenosis and disc herniation. They suggest that this technique represents a useful, alternative, minimally invasive method that can be used to treat lumbar foraminal stenosis and disc herniation.

Bi-portal Arthroscopic Spinal Surgery (BASS) with 30° arthroscopy for far lateral approach of L5-S1 - Technical note

Background context

Lumbar foraminal stenosis or extraforaminal stenosis is a common cause of spinal cord radiculopathy. Recently, several authors have introduced an endoscopy-based spinal surgery technique.

Purpose

The study aimed to introduce far lateral approach of biportal arthroscopic technique using 30° arthroscopy for foraminal decompression of L5-S1.

Study design

Technical note.

Patient sample

12 consecutive patients.

Outcome measures

The leg VAS with modified Macnab criteria was measured.

Result

The leg VAS improved from VAS 7.5 to 1.8.

Conclusion

Far lateral approach of BASS with 30° arthroscopy is an alternative method that can decompress foraminal stenosis minimally invasively.

State-of-the-art transforaminal percutaneous endoscopic lumbar surgery under local anesthesia: Discectomy, foraminoplasty, and ventral facetectomy

Transforaminal (TF) percutaneous endoscopic surgery for the lumbar spine under the local anesthesia was initiated in 2003 in Japan. Since it requires only an 8-mm skin incision and damage of the paravertebral muscles would be minimum, it would be the least invasive spinal surgery at present. At the beginning, the technique was used for discectomy; thus, the procedure was called PELD (percutaneous endoscopic lumbar discectomy). TF approach can be done under the local anesthesia, there are great benefits. During the surgery patients would be in awake and aware condition; thus, severe nerve root damage can be avoided. Furthermore, the procedure is possible for the elderly patients with poor general condition, which does not allow the general anesthesia. Historically, the technique was first applied for the herniated nucleus pulposus. Then, foraminoplasty, which is the enlargement surgery of the narrow foramen, became possible thanks to the development of the high speed drill. It was called the percutaneous endoscopic lumbar foraminoplasty (PELF). More recently, this technique was applied to decompress the lateral recess stenosis, and the technique was named percutaneous endoscopic ventral facetectomy (PEVF). In this review article, we explain in detail the development of the surgical technique of with time with showing our typical cases.

Clinical and Radiological Outcomes of Microscopic Lumbar Foraminal Decompression: A Pilot Analysis of Possible Risk Factors for Restenosis

A single-center retrospective comparative study was designed to identify the risk factors for restenosis of lumbar foraminal stenosis (LFS) after microscopic foraminal decompression (MFD). 21 consecutive patients who underwent single-level MFD with an average of 19-month follow-up were divided into two study groups based on clinical outcomes; group 1 (7 patients with poor outcomes requiring revision surgery), group 2 (14 patients with good outcomes with no revision surgery required). Changes of lumbar spinal alignment on plain standing radiographs were compared and analyzed between two study groups to investigate the pathology and risk factors associated with restenosis after MFD. Preoperative disc wedging (DW) angle was significantly larger in group 1 than in group 2 (3.5 ± 1.0° vs 1.1 ± 0.2°, P < 0.01). Postoperatively, disc height (DH) and foraminal height (FH) decreased (P < 0.05), and DW deteriorated (P < 0.01) significantly in group 1, while there were no significant changes in group 2. Lumbar lordosis (LL) remarkably improved postoperatively in group 2 (24.7 ± 8.0 to 32.0 ± 7.0, P < 0.001), contrary to limited improvement in group 1 (25.1 ± 9.2 to 27.0 ± 12.0, P = 0.45). Postoperative LL is a predictive factor for restenosis after MFD. Decrease in DH or progression of DW was contributing to restenosis. LFS presenting with large DW and lumbar degenerative kyphosis should be excluded from surgical indications for MFD without instrumented fusion, considering the high recurrence rate.

A new concept of transforaminal ventral facetectomy including simultaneous decompression of foraminal and lateral recess stenosis: Technical considerations in a fresh cadaver model and a literature review

Percutaneous endoscopic surgery for the lumbar spine, which was established in the last decade, requires only an 8-mm skin incision and causes minimal damage to the paravertebral muscles; thus, it is considered to be a minimally invasive technique for spinal surgery. It has been used to perform percutaneous endoscopic discectomy via two main approaches: the TF approach is a posterolateral one through the intervertebral foramen and can be done under local anesthesia; the IL approach is a more traditional one through the interlaminar space and is difficult to perform under local anesthesia. Recently, these techniques have been applied for lumbar spinal stenosis (LSS), the TF method for foraminal stenosis under local anesthesia, and the IL method for central and lateral recess stenosis under general anesthesia. In this study, using a fresh human cadaver model, we performed simultaneous decompression of the lateral recess and foraminal stenosis at L4-5 using the TF approach. Computed tomography confirmed enlargement of the lateral recess and intervertebral foramen. This technique, which can be performed under local anesthesia, should benefit elderly patients with LSS and poor general condition due to multiple comorbidities. Finally, we introduce the concept of percutaneous transforaminal ventral facetectomy using a spinal percutaneous endoscope. J. Med. Invest. 64: 1-6, February, 2017.

Radiographic Assessment on Magnetic Resonance Imaging after Percutaneous Endoscopic Lumbar Foraminotomy

Percutaneous endoscopic lumbar foraminotomy (ELF) is a novel minimally invasive technique used to treat lumbar foraminal stenosis. However, the validity of foraminal decompression based on quantitative assessment using magnetic resonance imaging (MRI) has not yet been established. The objective of this study was to investigate the radiographic efficiency of ELF using MRI. Radiographic changes of neuroforamen were measured based on pre- and postoperative MRI findings. Images were blindly analyzed by two observers for foraminal stenosis grade and foraminal dimensions. The intraclass correlation coefficient (ICC) and k statistic were calculated to determine interobserver agreement. Thirty-five patients with 40 neuroforamen were evaluated. The mean visual analog scale (VAS) score improved from 8.4 to 2.1, and the mean Oswestry disability index (ODI) improved from 65.9 to 19.2. Overall, 91.4% of the patients achieved good or excellent outcomes. The mean grade of foraminal stenosis significantly improved from 2.63 to 0.68. There were significant increases in the mean foraminal area (FA) from 50.05 to 92.03 mm², in mean foraminal height (FH) from 11.36 to 13.47 mm, in mean superior foraminal width (SFW) from 6.43 to 9.27 mm, and in mean middle foraminal width (MFW) from 1.47 to 78 mm (P < 0.001). Interobserver agreements for preoperative and postoperative measurements were good to excellent with the exception of SFW. In conclusion, foraminal dimensions and grades of foraminal stenosis significantly improved after ELF. These findings may enhance the clinical relevance of endoscopic lumbar foraminal decompression.

Percutaneous full endoscopic lumbar foraminoplasty for adjacent level foraminal stenosis following vertebral intersegmental fusion in an awake and aware patient under local anesthesia: A case report

Percutaneous endoscopic surgery for the lumbar spine has become established in the last decade. It requires only an 8 mm skin incision, causes minimal damage to the paravertebral muscles, and can be performed under local anesthesia. With the advent of improved equipment, in particular the high-speed surgical drill, the indications for percutaneous endoscopic surgery have expanded to include lumbar spinal canal stenosis. Transforaminal percutaneous endoscopic discectomy has been used to treat intervertebral stenosis. However, it has been reported that adjacent level disc degeneration and foraminal stenosis can occur following intervertebral segmental fusion. When this adjacent level pathology becomes symptomatic, additional fusion surgery is often needed. We performed minimally invasive percutaneous full endoscopic lumbar foraminoplasty in an awake and aware 50-year-old woman under local anesthesia. The procedure was successful with no complications. Her radiculopathy, including muscle weakness and leg pain due to impingement of the exiting nerve, improved after the surgery. J. Med. Invest. 64: 291-295, August, 2017.

Novel targeted puncture technique for percutaneous transforaminal endoscopic lumbar discectomy reduces X-ray exposure

The present study explored a method to reduce X-ray exposure dose and avoid targeted puncture complications in percutaneous transforaminal endoscopic lumbar discectomy (PTELD). A total of 66 patients with lumbar disc herniation were divided into two groups for a controlled study. In the experimental group, 31 patients were subjected to PTELD using a novel targeted puncture technique with application of a lumbar disc herniation target collimator. The remaining 35 patients in the control group were subjected to free-hand targeted puncture PTELD. The number of X-ray fluoroscopies performed intraoperatively, targeted puncture accuracy, visual analogue scale for surgical pain and Oswestry disability index of the two groups were statistically analyzed. The experimental and control groups exhibited a statistically significant difference in the number of X-ray fluoroscopies required during the procedure (P<0.01). The number of successful first targeted punctures was 27 (87.1%) in the experimental group and three (8.6%) in the control group, indicating that the puncture accuracy was higher in the experimental group than in the control group. As for the pain response to outer sleeve insertion (local anesthetic injection through the guide sleeve), the experimental group had 25 mild cases (80.6%), five moderate cases (16.1%) and one severe care (3.2%), whereas the control group had five mild cases (14.3%), 19 moderate cases (54.3%) and 11 severe cases (31.4%). These results demonstrated that the overall pain response of the experimental group was milder than that of control group. Due to a larger puncture deviation, the nerve root was touched by the puncture needle in 12 cases in the control group and resulted in one case of severe postoperative infection. In conclusion, the novel targeted puncture technique guided by a lumbar disc herniation target collimator outlined in the present study is able to markedly reduce X-ray exposure dose in PTELD and limit the surgical risk and pain experienced by patients. Mastering this novel puncture technique may aid those new to performing PTELD.

Usefulness of Percutaneous Endoscopic Lumbar Foraminoplasty for Lumbar Disc Herniation

OBJECTIVE

Endoscopic foraminoplasty facilitates engagement of the working cannula via the intervertebral foramen, allowing cannula access near a herniated disc (HD) for successful application of percutaneous endoscopic lumbar discectomy (PELD). The purpose of this study was to evaluate the efficacy of foraminoplasty for HD and propose applicable situations for foraminoplasty in PELD.

METHODS

A retrospective review of consecutive patients who underwent PELD was performed. Patients were divided into a foraminoplasty group (FG) and nonforaminoplasty group (NFG). Group differences in disc location and radiologic parameters, such as disc height (DH), foraminal width, lamina angle, facet angle, superior articular process thickness, and iliac height, were evaluated. Clinical outcomes were assessed using a visual analog scale for back and leg pain.

RESULTS

There were 136 patients (36 FG and 100 NFG) were. The FG had a significantly smaller DH and higher prevalence of high-grade down migration, downward sequestration, and recurrent HD compared with the NFG. For HDs at the L5-S1 level, the FG had a significantly greater iliac crest height and smaller DH and foraminal width compared with the NFG. For central HDs, the FG had a wider lamina angle and smaller DH compared with the NFG. Improvements in back and leg pain were similar in the 2 groups.

CONCLUSIONS

Percutaneous endoscopic lumbar foraminoplasty may be effective for small DH, migration, sequestration, recurrent HD, HD in L5-S1 with a high iliac crest, and central HD with a wide lamina angle.

Clinical and radiological outcomes of endoscopic partial facetectomy for degenerative lumbar foraminal stenosis

BACKGROUND

Several different techniques exist to treat degenerative lumbar foraminal stenosis. Failure to adequately decompress the lumbar foramen may lead to failed back surgery syndrome. However, wide decompression often causes spinal instabilities or may require an additional fusion surgery. The aim of this study was to report the outcomes of endoscopic partial facetectomy (EPF) performed on patients with degenerative lumbar foraminal stenosis.

METHODS

Between 2012 and 2014, 25 consecutive patients (12 women and 13 men) who underwent EPF were included in the study. The patients were assessed before surgery and followed-up regularly during outpatient visits (preoperatively and 1, 3, 6, 12, and 24 months postoperatively). The clinical outcomes were evaluated using the visual analog scale (VAS), Oswestry Disability Index (ODI), and Short Form-36 (SF-36) outcome questionnaire. The radiological outcome was measured using the lumbar Cobb angle, disc wedging angle, lumbar lordosis (LL), slip percentage, and disc height index (DHI) in plain standing radiographs.

RESULTS

The VAS, ODI, and SF-36 scores significantly improved at 1 month of follow-up compared with the baseline mean values and were maintained within the 2-year follow-up period. There was no radiologic progression in the lumbar Cobb's angle, disc wedging angle, LL, slip percentage, and DHI between preoperatively and 2 years postoperatively. In addition, the EPF with discectomy group and the EPF group were not significantly different in terms of clinical and radiological outcomes.

CONCLUSIONS

EPF is an effective option in decompressing the lumbar exiting nerve root without causing spinal instabilities for the treatment of patients with lumbar foraminal stenosis.

Suprapedicular Foraminal Endoscopic Approach to Lumbar Lateral Recess Decompression Surgery to Treat Degenerative Lumbar Spinal Stenosis

BACKGROUND To discuss the strategy of suprapedicular foraminal endoscopic approach to lumbar lateral recess decompression and evaluate the safety and effectiveness of this strategy. MATERIAL AND METHODS Complete clinical information of 52 cases of lumbar lateral recess decompression with therapy of suprapedicular foraminal endoscopic approach were analyzed during the period from February 2010 to April 2014 in the Third Hospital of Hebei. All patients were followed up for 24 months, and VAS, JOA, ODI, and LRD were compared between preoperative and postoperative therapy and changes of FA. Intraoperative and postoperative complications were recorded and the safety of the surgery was evaluated. The surgical "excellent" and "good" rates were evaluated using MacNab score. RESULTS VAS scores for lumbago and leg pain at 3, 6, 12, and 24 months after surgery were significantly lower than before surgery (p<0.05). JOA scores at 12 and 24 months after surgery were significantly higher than before surgery (p<0.05). ODI at 12 and 24 months after surgery were significantly lower than before surgery (p<0.05). LRD after surgery was higher (p<0.05), and FA was lower than before surgery. CONCLUSIONS Use of the suprapedicular foraminal endoscopic approach to lumbar lateral recess decompression is safe and effective, and this minimally invasive treatment can achieve satisfactory results, especially for elderly patients with complicated underlying diseases.

Early experience with endoscopic foraminotomy in patients with moderate degenerative deformity

OBJECTIVE Asymmetrical degeneration of the disc is one of the most common causes of primary degenerative scoliosis in adults. Coronal deformity is usually less symptomatic than a sagittal deformity because there is less expenditure of energy and hence less effort to maintain upright posture. However, nerve root compression at the fractional curve or at the concave side of the main curve can give rise to debilitating radiculopathy. METHODS This study was a retrospective analysis of 16 patients with coronal deformity of between 10° and 20°. All patients underwent endoscopic foraminal decompression surgery. The pre- and postoperative Cobb angle, visual analog scale (VAS), 36-Item Short Form Health Survey (SF-36), and Oswestry Disability Index scores were measured. RESULTS The average age of the patients was 70.0 ± 15.5 years (mean ± SD, range 61-86 years), with a mean followup of 7.5 ± 5.3 months (range 2-14 months). The average coronal deformity was 16.8° ± 4.7° (range 10°-41°). In 8 patients the symptomatic foraminal stenosis was at the level of the fractional curve, and in the remaining patients it was at the concave side of the main curve. One of the patients included in the current cohort had to undergo a repeat operation within 1 week for another disc herniation at the adjacent level. One patient had CSF leakage, which was repaired intraoperatively, and no further complications were noted. On average, preoperative VAS and SF-36 scores showed a tendency for improvement, whereas a dramatic reduction of VAS, by 65% (p = 0.003), was observed in radicular leg pain. CONCLUSIONS Patients with mild to moderate spinal deformity are often compensated and have tolerable levels of back pain. However, unilateral radicular pain resulting from foraminal stenosis can be debilitating. In select cases, an endoscopic discectomy or foraminotomy enables the surgeon to decompress the symptomatic foramen with preservation of essential biomechanical structures, delaying the need for a major deformity correction surgery.

Comparison of safety and efficiency of microendoscopic discectomy with automatic nerve retractor and with nerve hook

This study compares the safety and efficiency of two techniques in microendoscopic discectomy (MED) for lumbar disc herniation. The two techniques are MED with automatic nerve retractor and MED with nerve hook which had been widely used for many years. The former involves a newly developed MED device which contains three parts to protect nerve roots during operation. Four hundred and twenty-eight patients underwent MED treatments between October 2010 and September 2015 were recruited and randomized to either intraoperative utilization of automatic nerve retractor (n = 315, group A) or application of nerve hook during surgery (n = 113, group B). Operation time and intraoperative bleeding volume were evaluated. Simultaneously, Visual Analogue Scales (VAS) and muscle strength grading were performed preoperatively, and 1, 2, 3 days, 1, 2 weeks, 3 and 6 months postoperatively. No dramatic difference of pain intensity was observed between the two groups before surgery and 6 months after surgery (P > 0.05). The operation time was shorter in group A (30.30 ± 1.89 min) than that in group B (59.41 ± 3.25 min). Group A (67.83 ± 13.14 ml) experienced a significant decrease in the amount of blood loss volume when compared with group B (100.04 ± 15.10 ml). There were remarkable differences of VAS score and muscle strength grading after postoperative 1, 2, 3 days, 1, 2 weeks and 3 months between both groups (P ≤ 0.05). MED with automatic nerve retractor effectively shortened operation time, decreased the amount of bleeding, down-regulated the incidence of nerve traction injury.

Percutaneous thoracolumbar decompression combined with percutaneous pedicle screw fixation and fusion: a method for treating spinal degenerative pain in a biplane angiography suite with the avoidance of general anesthesia

BACKGROUND

Spondylytic degeneration of the axial lumbar spine is a major cause of pain and disability. Recent advances in spinal surgical instrumentation, including percutaneous access and fusion techniques, have made possible the performance of instrumented fusion through small incisions. By blending strategies of interventional pain management, neuroradiology, and conventional spine surgery, it is now feasible to treat spinal axial pain using permanent fixation techniques and local anesthesia in the setting of a fluoroscopy suite using mild sedation and local anesthesia.

METHODS

The author presents a series of percutaneous thoracolumbar fusion procedures performed in a biplane neuroangiographic suite and without general anesthesia for the treatment of spondylytic pain. All procedures utilized pedicle screw fixation, harvesting of local bone autograft, and application of bone fusion material.

RESULTS

In this series of 13 patients, a statistically significant reduction of pain was seen at both the 2-week post-operative timepoint, as well as at the time of longest follow-up (mean 40 weeks).

DISCUSSION

The advanced and rapid imaging capabilities afforded by a neuroangiographic suite can be safely combined with percutaneous fusion techniques so as to allow for fusion therapies to be applied to patients where the avoidance of general anesthesia is desirable.

Lumbar Neuroforaminal Decompression with a Flexible Microblade Shaver System: Results of a Cadaveric Study

BACKGROUND

The lumbar neural foraminal stenosis still is a challenging condition in minimally invasive spine surgery. Because of the anatomic situation a complete decompression of the nerve root often leads to a subtotal facetectomy associated with potential instability and the need for additional instrumentation of the decompressed segment. The iO-Flex system was introduced to address this problem by using a minimally invasive wire-guided microblade shaver to increase the neuroforaminal space by reducing the stenosis from intraforaminal while sparing bigger parts of the facet joint. In this study, we evaluated the feasibility and the surgical and radiological success in relation to the experience of the surgeon.

METHODS

We performed decompression of the neuroforamen in 10 lumbar levels of 2 fresh-frozen human cadavers. Before and after decompression, we obtained high-resolution computed tomography data to evaluate the diameter of the neural foramen.

RESULTS

The mean foraminal width (7.88-10.94 mm, P < 0.0001) and area (123.27-149.18 mm², P < 0.003) increased significantly after the decompression, whereas the facet joints area (131.9-107.51 mm², P < 0.005) and width (16.4-13.75 mm, P < 0.001) indeed decreased significantly but with an overall reduction of facet joint width by 16% and facet joint area by 18%. No complications such as nerve root damages or dural tears were observed.

CONCLUSIONS

The flexible micro blade shaver system is feasible with a steep learning curve and achieves sufficient decompression of the neuroforamen in this cadaveric study.

How I do it? Biportal endoscopic spinal surgery (BESS) for treatment of lumbar spinal stenosis

BACKGROUND

Prevalent endoscopic spine surgeries have shown limitations especially in spinal stenosis (Ahn in Neurosurgery 75(2):124-133, 2014). Biportal endoscopic surgery is introduced to manage central and foraminal stenosis with its wide range of access angle and clear view.

METHODS

The authors provide an introduction of this technique followed by a description of the surgical anatomy with discussion on its indications and advantages. In particular, tricks to avoid complications are also presented.

CONCLUSIONS

Effective circumferential and focal decompression were achieved in most cases without damage to the spinal structural integrity with preservation of muscular and ligamentous attachments. The biportal endoscopic spinal surgery (BESS) may be safely used as an alternative minimally invasive procedure for lumbar spinal stenosis (Figs. 1 and 2).

Foraminoplastic Superior Vertebral Notch Approach with Reamers in Percutaneous Endoscopic Lumbar Discectomy : Technical Note and Clinical Outcome in Limited Indications of Percutaneous Endoscopic Lumbar Discectomy

To describe the details of the foraminoplastic superior vertebral notch approach (FSVNA) with reamers in percutaneous endoscopic lumbar discectomy (PELD) and to demonstrate the clinical outcomes in limited indications of PELD. Retrospective data were collected from 64 patients who underwent PELD with FSVNA from August 2012 to April 2014. Inclusion criteria were high grade migrated disc, high canal compromised disc, and disc protrusion combined with foraminal stenosis. The clinical outcomes were assessed using by the visual analogue scale (VAS), Oswestry Disability Index (ODI) and modified MacNab criteria. Complications related to the surgery were reviewed. The procedure used a unique approach, using the superior vertebral notch as the target and performing foraminoplasty with only reamers under C-arm control. The mean age of the 55 female and 32 male patients was 52.73 years. The mean F/U period was 12.2±4.2 months. Preoperative VAS (8.24±1.25) and ODI (67.8±15.4) score improved significantly at the last follow-up (VAS, 1.93±1.78; ODI, 17.14±15.7). Based on the modified MacNab criteria, excellent or good results were obtained in 95.3% of the patients. Postoperative transient dysthesia (n=2) and reoperation (n=1) due to recurred disc were reported. PELD with FSVNA could be a good method for treating lumbar disc herniation. This procedure may offer safe and efficacious results, especially in the relatively limited indications for PELD.

Percutaneous lumbar foraminoplasty and percutaneous endoscopic lumbar decompression for lateral recess stenosis through transforaminal approach: Technique notes and 2 years follow-up

OBJECTIVE

To evaluate the outcome and safety of percutaneous lumbar foraminoplasty (PLF) and percutaneous endoscopic lumbar decompression (PELD) with specially designed instrument for lumbar lateral recess stenosis with/without herniated discs (HDs).

METHOD

From August of 2011 to August of 2013, 96 patients met the inclusion criteria were treated with PLF-PELD and 85 cases were followed up to 2 years postoperatively. MRI or CT checkup performed in the next morning after operation. Outcomes of symptoms were evaluated by follow-up interviews at 3 months, 6 months, 1 year and 2 years after surgery. Low back pain and leg pain were measured by Visual Analog Scale (VAS) score (1-100). Functional outcomes were assessed by using Oswestry Disability Index (ODI) and modified MacNab criteria.

RESULT

Two years follow-up data were obtained from 85 cases, including 14 cases on unilateral L3-4, 1 case on bilateral L3-4, 49 cases on unilateral L4-5, 3 cases on bilateral L4-5, 12 cases on unilateral L5S1, 1 case on bilateral L5S1, 3 cases on unilateral L3-5 and 2 cases on unilateral L4-S1. So totally 95 lumbar lateral recesses were decompressed. Patients ranged in age from 46-78 years (mean age, 56.7 years), including 36 males and 49 females. 56 cases combined with HDs. Low back pain and leg pain were significantly relieved after surgery in all patients. 3 patients were complicated with dysesthesia in distribution of exiting nerve that was all operated at L5S1. Postoperative MRI/CT examination showed adequate decompression of lateral recess and removal of combined HDs in all patients. No patient had postoperative infection, dysfunctional nerve root injury or iatrogenic segmental instability. 2 cases experienced recurrence of combined HDs (2.4%), but could not undertake further revision surgery because of infirm condition. All the 85 cases were analyzed with complete follow-up data. VAS scores and ODI values were significantly lower in all time-points after surgery than before surgery. MacNab scores at 2 years after surgery were obtained from all the 85 patients. 29 cases were given "excellent"; 48 were given "good". 6 patients experienced heavier low back pain, thus being classified as "fair". 2 cases with recurrence were given "poor".

CONCLUSIONS

PLF-PELD with specially designed instrument is a less invasive, effective and safe surgery for lumbar lateral recess stenosis with/without combined HDs.