Percutaneous endoscopic lumbar discectomy for migrated disc herniation: classification of disc migration and surgical approaches

"Outside-in" technique, clinical results, and indications with transforaminal lumbar endoscopic surgery: a retrospective study on 220 patients on applied radiographic classification of foraminal spinal stenosis

Objective

To analyze and describe appropriate surgical indications for endoscopically performed transforaminal decompression with the outside-in technique with foraminoplasty in patients with lateral stenosis with and without herniated disc.

Background and Significance

Endoscopic microdiscectomy is growing in popularity for the removal of lumbar disc herniations. Recent advances in surgical techniques allow for percutaneous endoscopically assisted bony decompression as well.

Materials and Methods

A retrospective study of 220 consecutive patients undergoing percutaneous endoscopic transforaminal foraminoplasty and microdiscectomy at 228 levels was conducted with intent of identifying appropriate surgical indications in patients with monoradiculopathy. The mean follow up was 46 months ranging from 26 to 54 months. Preoperatively, foraminal and lateral recess stenosis was graded on preoperative MRI and CT scans by dividing the lumbar neuroforamen into three zones: a) entry zone, b) middle zone, and c) exit zone. In addition, the presence of disc herniation causing neural element compression in the lateral recess and neuroforamen was noted. Disc herniations, if present, were recorded as either extruded and contained disc herniations. Surgical outcomes were classified according to the Macnab criteria. In addition, reductions in VAS scores were assessed.

Results

According to the Macnab criteria, excellent and good results were obtained in 85% (186/220) of patients with monoradiculopathy. The mean VAS score decreased from 7.5 ± 1.5 preoperatively to 2.8 ± 1.9 at the final follow-up (P < 0.01). Concomitant extruded disc herniations and contained disc bulges were recorded in 24 and 82 patients, respectively. There were no approach-related complications. Clinical failures occurred in patients with bony stenosis in the lateral recess and entry zone of the neuroforamen. Less favorable outcomes were observed in patients with concomitant contained disc herniations when compared to extruded disc herniations (P < 0.03) as well in patients older than 50 years of age (P < 0.021).

Conclusions

Percutaneous, endoscopic decompression using outside-in technique works well in patients with monoradiculopathy due to lateral stenosis in the mid and exit zone of the neuroforamen. Decompression in the entry zone maybe inadequate using the transforaminal outside-in approach. Future studies with greater statistical power should determine as to whether pain relief was achieved via microdiscectomy or foraminoplasty.

The "inside out" transforaminal technique to treat lumbar spinal pain in an awake and aware patient under local anesthesia: results and a review of the literature

Surgical management of back and leg pain is evolving and changing due to a better understanding of the patho-anatomy well correlated with its pathophysiology. Pain is better understood with in vivo visualization and probing of the pain generators using an endoscopic access rather than just relying on symptoms diagram and image correlation. This has resulted in a shared decision making involving patient and surgeon, focused on a broader spectrum of surgical as well as non-surgical treatments, and not just masking the pain generator. It has moved away from decisions based on diagnostic images alone, that, while noting the image alterations, cannot explain the pain experienced by each individual as images do not always show variations in nerve supply and patho-anatomy. The ability to isolate and visualize "pain" generators in the foramen and treating persistent pain by visualizing inflammation and compression of nerves, serves as the basis for transforaminal endoscopic (TFE) surgery. This has also resulted in better pre surgical planning with more specific and defined goals in mind. The "Inside out" philosophy of TFE surgery is safe and precise. It provides basic access to the disc and foramen to cover a large spectrum of painful pathologies.

Early postoperative results after removal of cranially migrated lumbar disc prolapse: retrospective comparison of three different surgical strategies

Background. To compare the early postoperative results of three surgical approaches to lumbar disc herniations that migrated cranially. Minimally invasive techniques such as the translaminar and endoscopic transforaminal approaches are utilized in patients with lumbar disc herniations to gain access to cranially located disc material and to avoid the potentially destabilizing resection of ligament and bone tissue, which is associated with an extended interlaminar approach. Methods. This retrospective study compares the postoperative pain and functional capacity levels of 69 patients who underwent an interlaminar (Group A, n = 27), a translaminar (Group B, n = 22), or an endoscopic transforaminal procedure (Group C, n = 20). Results. Median VAS scores for leg pain decreased significantly from before to after surgery in all groups. Surgical revisions were required in thirteen cases (five in Group A, one in Group B, and seven in Group C; P = 0.031). After six weeks, there were significant differences in back pain and functional outcome scores and in the results for the MacNab criteria but not in leg pain scores. Conclusions. The interlaminar and translaminar techniques were the safest and fastest ways of gaining access to cranially migrated disc material and the most effective approaches over a period of six weeks.

Migration patterns of herniated disc fragments: a study on 1,020 patients with extruded lumbar disc herniation

BACKGROUND CONTEXT

Herniated disc fragments are known to migrate in various directions within the spinal canal. To date, no comprehensive studies have been undertaken to examine the migration patterns of herniated disc material using a standard nomenclature and classification system.

PURPOSE

To report migration patterns of extruded lumbar disc fragments.

STUDY DESIGN

A review of magnetic resonance (MR) images.

PATIENT SAMPLE

A total of 1,020 consecutive Azeri patients with symptomatic extruded lumbar intervertebral disc herniation.

OUTCOME MEASURES

Migration patterns of extruded lumbar disc fragments in vertical and horizontal planes and their association with age, gender, body mass index (BMI), and the level of herniation.

METHODS

High-quality axial and sagittal MR images of the lumbar spine were used. Disc material that was displaced away from the site of extrusion, regardless of continuity, was considered "migrated." The migration patterns observed were rostral or caudal in the vertical plane and central, paracentral, subarticular, foraminal, or extraforaminal in the horizontal plane.

RESULTS

In the vertical plane, rostral and caudal migrations were observed in 27.8% and 72.2% of the patients, respectively. The number of rostral migrations increased significantly with increasing age and in higher levels in the lumbar spine (p<.001 for both). Radiculopathy was significantly more frequent in caudal migrations than in rostral migrations (78.9% vs. 65.1%, p<.001). There was no significant association between gender or BMI and migration patterns in the vertical plane. In the horizontal plane, central, paracentral, subarticular, foraminal, and extraforaminal migrations were reported in 17.3%, 74.2%, 4.3%, 2.5%, and 1.8% of the patients, respectively. The youngest (median age 39 years, interquartile range [IQR] 13 years) and the oldest (median age 55 years, IQR 15 years) groups of patients (p<.001) had the most formainal and extraforaminal migrations, respectively. Radiculopathy was present in 66.5%, 76.8%, 88.6%, 96%, and 27.8% of the patients with central, paracentral, subarticular, foraminal, and extraforaminal migrations, respectively (p<.001). No significant association was found between gender, BMI, or the level of herniation and migration pattern in the horizontal plane.

CONCLUSIONS

Caudal and paracentral migrations are the most common patterns of migration in patients with extruded lumbar disc herniation in the vertical and horizontal planes, respectively. Age and the level of herniation may affect the migration patterns of herniated lumbar disc material.

Comparison of tissue damages caused by endoscopic lumbar discectomy and traditional lumbar discectomy: a randomised controlled trial

OBJECTIVES

This study aimed to compare the clinical efficacies of percutaneous endoscopic lumbar discectomy (PELD) and traditional open lumbar discectomy (OD).

METHODS

The pre-operative and post-operative blood loss, hospital stays and wound sizes of the patients in the two groups were recorded. Enzyme-Linked immunosorbent assay was used to measure the changes of interleukin-6 (IL-6), C-reactive protein (CRP) and creatine phosphokinase (CPK) pre-operation and 1 h, 6 h, 12 h, 24 h and 48 h after corresponding surgery. Visual Analog Scale and Modified MacNab Criteria were used to assess post-operative results.

RESULTS

Patients in the PELD group had less blood loss (p < 0.01), shorter hospitalization hours (p < 0.01) and smaller surgical wounds (p < 0.01) than the patients underwent traditional OD surgery. MacNab evaluated that the levels of satisfaction were above 90% in both groups post-operative six months. There was no significant difference in pain index between the two groups (p > 0.05). Furthermore, the levels of CRP, CPK and IL-6 in the PELD group were all lower than those in the OD group with a significant difference (p < 0.01).

CONCLUSION

The PELD had less damage to human tissues than the traditional OD. PELD has a clear promotional value in clinical.

Clinical results of XMR-assisted percutaneous transforaminal endoscopic lumbar discectomy

Background

Although percutaneous endoscopic lumbar discectomy (PELD) has shown favorable outcomes in the majority of lumbar discectomy cases, there were also some failures. The most common cause of failure is the incomplete removal of disc fragments. The skin entry point for the guide-needle trajectory and the optimal placement of the working sleeve are largely blind, which might lead to the inadequate removal of disc fragments. The objective of this study was to present our early experiences with image-guided PELD using a specially designed fluoroscope with magnetic resonance imaging-equipped operative suite (XMR) for the treatment of lumbar disc herniation.

Methods

This prospective study included 89 patients who had undergone PELD via the transforaminal approach using an XMR protocol. Pre- and postoperative examinations (at 12 weeks) included a detailed clinical history, visual analogue scale (VAS), Oswestry disability index (ODI), and radiological workups. The results were categorized as excellent, good, fair, and poor according to MacNab's criteria. At the final follow-up, the minimum follow-up time for the subjects was 2 years. The need for revision surgeries and postoperative complications were noted on follow-up.

Results

Postoperative mean ODI decreased from 67.4% to 5.61%. Mean VAS score for back and leg pain improved significantly from 4 to 2.3 and from 7.99 to 1.04, respectively. Four (4.49%) patients underwent a second-stage PELD after intraoperative XMR had shown remnant fragments after the first stage. As per MacNab's criteria, 76 patients (85.4%) showed excellent, 8 (8.89%) good, 3 (3.37%) fair, and 2 (2.25) poor results. Four (4.49%) patients had remnant disc fragments on XMR, which were removed during the same procedure. All of these patients had either highly migrated or sequestrated disc fragments preoperatively. Four (4.49%) other patients needed a second, open surgery due to symptomatic postoperative hematoma (n = 2) and recurrent disc herniation (n = 2).

Conclusions

This prospective analysis indicates that XMR-assisted PELD provides a precise skin entry point. It also confirms that decompression occurs intraoperatively, which negates the need for a separate surgery and thus increases the success rate of PELD, particularly in highly migrated or sequestrated discs. However, further extensive experience is required to confirm the advantages and feasibility of PELD in terms of cost effectiveness.

Transforaminal percutaneous endoscopic lumbar discectomy: technical tips to prevent complications

Transforaminal percutaneous endoscopic lumbar discectomy is regarded as an effective alternative to open discectomy. Remarkable technical evolution now enables selective endoscopic removal of an epidurally extruded disc fragment. As a result, the surgical indications for this technique are becoming broader. However, as the use of endoscopic techniques increases in spinal procedures, related complications emerge as important problems. These include postoperative dysesthesia, dural tears, hematoma, infection and visceral injury. There are several technical guidelines to increase the effectiveness of endoscopic techniques and prevent complications. Initial landing should be as close to the target as possible. Complete herniotomy after thorough release of annular anchorage is a key to success. The definitive end point of the procedure is free mobilization of neural tissues, not direct exposure of neural tissues.

The obturator guiding technique in percutaneous endoscopic lumbar discectomy

In conventional percutaneous disc surgery, introducing instruments into disc space starts by inserting a guide needle into the triangular working zone. However, landing the guide needle tip on the annular window is a challenging step in endoscopic discectomy. Surgeons tend to repeat the needling procedure to reach an optimal position on the annular target. Obturator guiding technique is a modification of standard endoscopic lumbar discectomy, in which, obturator is used to access triangular working zone instead of a guide needle. Obturator guiding technique provides more vivid feedback and easy manipulation. This technique decreases the steps of inserting instruments and takes safer route from the peritoneum.

Percutaneous endoscopic lumbar discectomy via contralateral approach: a technical case report

STUDY DESIGN

Technical case report.

OBJECTIVE

The authors report a new percutaneous endoscopic lumbar discectomy (PELD) technique for the treatment of lumbar disc herniation via a contralateral approach.

SUMMARY OF BACKGROUND DATA

When there are highly down-migrated lumbar disc herniation along just medial to pedicle and narrow ipsilateral intervertebral foramen, the conventional PELD is not easily accessible via ipsilateral transforaminal route.

METHODS

Five patients manifested gluteal and leg pain because of a soft disc herniation at the L4-L5 level. Transforaminal PELD via a contralateral approach was performed to remove the herniated fragment, achieving complete decompression of the nerve root.

RESULTS

The symptom was relieved and the patient was discharged the next day.

CONCLUSION

When a conventional transforaminal PELD is difficult because of some anatomical reasons, PELD via a contralateral route could be a good alternative option in selected cases.

Revisional percutaneous full endoscopic disc surgery for recurrent herniation of previous open lumbar discectomy

Study Design

A retrospective study.

Purpose

To determine the feasibility and effectiveness of revisional percutaneous full endoscopic discectomy for recurrent herniation after conventional open disc surgery.

Overview of the Literature

Repeated open discectomy with or without fusion has been the most common procedure for recurrent lumbar disc herniation. Percutaneous endoscopic lumbar discectomy for recurrent herniation has been thought of as an impossible procedure. Despite good results with open revisional surgery, major problems may be caused by injuries to the posterior stabilized structures. Our team did revisional full endoscopic lumbar disc surgery on the basis of our experience doing primary full endoscopic disc surgery.

Methods

Between February 2004 and August 2009 a total of 41 patients in our hospital underwent revisional percutaneous endoscopic lumbar discectomy using a YESS endoscopic system and a micro-osteotome (designed by the authors). Indications for surgery were recurrent disc herniation following conventional open discectomy; with compression of the nerve root revealed by Gadolinium-enhanced magnetic resonance imaging; corresponding radiating pain which was not alleviated after conservative management over 6 weeks. Patients with severe neurologic deficits and isolated back pain were excluded.

Results

The mean follow-up period was 16 months (range, 13 to 42 months). The visual analog scale for pain in the leg and back showed significant post-treatment improvement (p < 0.001). Based on a modified version of MacNab's criteria, 90.2% showed excellent or good outcomes. There was no measurable blood loss. There were two cases of recurrence of and four cases with complications.

Conclusions

Percutaneous full-endoscopic revisional disc surgery without additional structural damage is feasible and effective in terms of there being less chance of fusion and bleeding. This technique can be an alternative to conventional repeated discectomy.

Symptomatic post-discectomy pseudocyst after endoscopic lumbar discectomy

OBJECTIVE

The objectives of this study were to determine the frequency of symptomatic postdiscectomy pseudocyst (PP) after endoscopic discectomy and to compare the results of surgical and conservative management of them.

METHODS

Initial study participants were 1,503 cases (1,406 patients) receiving endoscopic lumbar discectomy by 23-member board of neurosurgeons from March 2003 to October 2008. All patients' postoperative magnetic resonance imaging (MRI) scans were evaluated. On the postoperative MRI, cystic lesion of T2W high and T1W low at discectomy site was regarded as PP. Reviews of medical records and radiological findings were done. The PP patients were divided into two groups, surgical and conservative management by treatment modality after PP detection. We compared the results of the two groups using the visual analogue scale (VAS) for low back pain (LBP), VAS for leg pain (LP) and the Oswestry disability index (ODI).

RESULTS

Among 1,503 cases of all male soldiers, the MRIs showed that pseudocysts formed in 15 patients, about 1.0% of the initial cases. The mean postoperative interval from surgery to PP detection was 53.7 days. Interlaminar approach was correlated with PP formation compared with transforaminal approach (p=0.001). The mean VAS for LBP and LP in the surgical group improved from 6.5 and 4.8 to 2.0 and 2.3, respectively. The mean VAS for LBP and LP in the conservative group improved from 4.4 and 4.4 to 3.9 and 2.3, respectively. There was no difference in treatment outcome between surgical and conservative management of symptomatic PP.

CONCLUSION

Although this study was done in limited environment, symptomatic PP was detected at two months' postoperative period in about 1% of cases. Interlaminar approach seems to be more related with PP compared with transforaminal approach.

Pyogenic spondylodiscitis after percutaneous endoscopic lumbar discectomy

We reviewed 9 cases of pyogenic spondylodiscitis following percutaneous endoscopic lumbar discectomy (PELD). Microbiologic cultures revealed 6 causative organisms. Five patients were managed conservatively and four were treated surgically. The mean follow-up period was 20.6 months and the average length of hospitalization was 24 days. Radiological evidence of spinal fusion was noted and infection was resolved in all patients. Although PELD is a safe and effective procedure, the possibility of pyogenic spondylodiscitis should always be considered.

Inadvertent discogram during transforaminal epidural injection in patients with lumbar disc herniation -A report of 2 cases-

The transforaminal epidural injection (TFEI) has been preferred in many cases because it can deliver the injected dose of medication closer to the nerve root and better facilitate ventral epidural flow compared to other methods. However, in patients with deformities not demonstrated on fluoroscopic imaging, the needle may enter unwanted locations. We treated two cases of intradiscal injection of contrast dye, during the TFEI, in patients with lumbar disc herniation.

Comparison of percutaneous endoscopic lumbar discectomy and open lumbar microdiscectomy for recurrent disc herniation

OBJECTIVE

The purpose of this study was to compare clinical and radiological outcomes of percutaneous endoscopic lumbar discectomy (PELD) and open lumbar microdiscectomy (OLM) for recurrent disc herniation.

METHODS

Fifty-four patients, who underwent surgery, either PELD (25 patients) or repeated OLM (29 patients), due to recurrent disc herniation at L4-5 level, were divided into two groups according to the surgical methods. Excluded were patients with sequestrated disc, calcified disc, severe neurological deficit, or instability. Clinical outcomes were assessed using Visual Analogue Scale (VAS) score and Oswestry Disability Index (ODI). Radiological variables were assessed using plain radiography and/or magnetic resonance imaging.

RESULTS

Mean operating time and hospital stay were significantly shorter in PELD group (45.8 minutes and 0.9 day, respectively) than OLM group (73.8 minutes and 3.8 days, respectively) (p < 0.001). Complications occurred in 4% in PELD group and 10.3% in OLM group in the perioperative period. At a mean follow-up duration of 34.2 months, the mean improvements of back pain, leg pain, and functional improvement were 4.0, 5.5, and 40.9% for PELD group and 2.3, 5.1, and 45.0% for OLM group, respectively. Second recurrence occurred in 4% after PELD and 10.3% after OLM. Disc height did not change after PELD, but significantly decreased after OLM (p = 0.0001). Neither sagittal rotation angle nor volume of multifidus muscle changed significantly in both groups.

CONCLUSION

Both PELD and repeated OLM showed favorable outcomes for recurrent disc herniation, but PELD had advantages in terms of shorter operating time, hospital stay, and disc height preservation.

Strategies for Noncontained Lumbar Disc Herniation by an Endoscopic Approach : Transforaminal Suprapedicular Approach, Semi-Rigid Flexible Curved Probe, and 3-Dimensional Reconstruction CT with Discogram

OBJECTIVE

The purpose of this study was to evaluate the efficacy of a transforaminal suprapedicular approach, semi-rigid flexible curved probe, and 3-dimensional reconstruction computed tomography (3D-CT) with discogram in the endoscopic treatment of non-contained lumbar disc herniations.

METHODS

The subjects were 153 patients with difficult, non-contained lumbar disc herniations undergoing endoscopic treatment. The types of herniation were as follows : extraforaminal, 17 patients; foraminal, 21 patients; high grade migration, 59 patients; and high canal compromise, 56 patients. To overcome the difficulties in endoscopic treatment, the anatomic structures were analyzed by 3D reconstruction CT and the high grade disc was extracted using a semi-rigid flexible curved probe and a transforaminal suprapedicular approach.

RESULTS

The mean follow-up was 18.3 months. The mean visual analogue scale (VAS) of the patients prior to surgery was 9.48, and the mean postoperative VAS was 1.63. According to Macnab's criteria, 145 patients had excellent and good results, and thus satisfactory results were obtained in 94.77% cases.

CONCLUSION

In a posterolateral endoscopic lumbar discectomy, the difficult, non-contained disc is considered to be the most important factor impeding the success of surgery. By applying a semi-rigid flexible curved probe and using a transforaminal suprapedicular approach, good surgical results can be obtained, even in high grade, non-contained disc herniations.

Transforaminal endoscopic surgery for symptomatic lumbar disc herniations: a systematic review of the literature

The study design includes a systematic literature review. The objective of the study was to evaluate the effectiveness of transforaminal endoscopic surgery and to compare this with open microdiscectomy in patients with symptomatic lumbar disc herniations. Transforaminal endoscopic techniques for patients with symptomatic lumbar disc herniations have become increasingly popular. The literature has not yet been systematically reviewed. A comprehensive systematic literature search of the MEDLINE and EMBASE databases was performed up to May 2008. Two reviewers independently checked all retrieved titles and abstracts and relevant full text articles for inclusion criteria. Included articles were assessed for quality and outcomes were extracted by the two reviewers independently. One randomized controlled trial, 7 non-randomized controlled trials and 31 observational studies were identified. Studies were heterogeneous regarding patient selection, indications, operation techniques, follow-up period and outcome measures and the methodological quality of these studies was poor. The eight trials did not find any statistically significant differences in leg pain reduction between the transforaminal endoscopic surgery group (89%) and the open microdiscectomy group (87%); overall improvement (84 vs. 78%), re-operation rate (6.8 vs. 4.7%) and complication rate (1.5 vs. 1%), respectively. In conclusion, current evidence on the effectiveness of transforaminal endoscopic surgery is poor and does not provide valid information to either support or refute using this type of surgery in patients with symptomatic lumbar disc herniations. High-quality randomized controlled trials with sufficiently large sample sizes are direly needed to evaluate if transforaminal endoscopic surgery is more effective than open microdiscectomy.

Transforaminal percutaneous endoscopic lumbar discectomy for upper lumbar disc herniation: clinical outcome, prognostic factors, and technical consideration

BACKGROUND

Compared with lower lumbar disc herniations, upper lumbar disc herniations at L1-L2 and L2-L3 have specific characteristics that result in different surgical outcomes after conventional open discectomy. There are no published studies on the feasibility of percutaneous endoscopic lumbar discectomy for upper lumbar disc herniation. The purpose of this study was to assess the clinical outcome, prognostic factors and the technical pitfalls of PELD for upper lumbar disc herniation.

METHOD

Forty-five patients with a soft disc herniation at L1-L2 or L2-L3 underwent percutaneous endoscopic discectomy. Posterolateral transforaminal endoscopic laser-assisted disc removal was performed under local anesthesia. Clinical outcomes was assessed using the Prolo scale. The prognostic factors associated with outcome were then analyzed.

FINDINGS

The mean follow-up was 38.8 months (range, 25-52 months). The outcome of the 45 patients was excellent in 21 (46.7%), good in 14 patients (31.1%), fair in six patients (13.3%), and poor in four patients (8.9%). Four patients with a poor outcome underwent further open surgery. Mean scores on a visual analog scale decreased from 8.38 to 2.36 (P < 0.0001). Age less than 45 years and a lateral disc herniation were independently associated with an excellent outcome (P < 0.05).

CONCLUSIONS

Patient selection and an anatomically modified surgical technique promote a more successful outcome after percutaneous endoscopic discectomy for upper lumbar disc herniation.

Endoscopic transforaminal suprapedicular approach in high grade inferior migrated lumbar disc herniation

OBJECTIVE

Although endoscopic procedures for lumbar disc diseases have improved greatly, the postoperative outcomes for high grade inferior migrated discs are not satisfactory. Because of anatomic limitations, a rigid endoscope cannot reach all lesions effectively. The purpose of this study was to determine the feasibility of endoscopic transforaminal suprapedicular approach to high grade inferior-migrated lumbar disc herniations.

METHODS

Between May 2006 and March 2008, a suprapedicular approach was performed in 53 patients with high grade inferior-migrated lumbar disc herniations using a rigid endoscope and a semi-rigid flexible curved probe. One-to-four hours after surgery, the presence of remnant discs was checked with MRI. The outcomes were evaluated with the visual analogue scale (VAS) score and the Oswestry Disability Index (ODI) one week after surgery.

RESULTS

The L2-3 level was involved in 2 patients and the L3-4 level was involved in 14 patients, while the L4-5 level was involved in 39 patients. There were single piece-type in 34 cases and a multiple piece-type in 19 cases. Satisfactory results were obtained in all cases. The mean preoperative VAS for leg pain was 9.32+/-0.43 points (range, 7-10 points), whereas the mean ODI was 79.82+/-4.53 points (range, 68-92 points). At the last follow-up examination, the mean postoperative VAS for leg pain was 1.78+/-0.71 points and the mean postoperative ODI improved to 15.27+/-3.82 points.

CONCLUSION

A high grade inferior migrated lumbar disc is difficult to remove sufficiently by posterolateral endoscopic lumbar dscectomy using a rigid endoscope. However, a satisfactory result can be obtained by applying a transforaminal suprapedicular approach with a flexible semi-rigid curved probe.

Learning curve for percutaneous endoscopic lumbar discectomy

Percutaneous endoscopic lumbar discectomy (PELD) is one of the surgical options for soft lumbar disk herniation, but the learning curve is perceived to be steep. The first 51 PELD cases performed for single-level intracanalicular lumbar disk herniation causing radiculopathy by the same surgeon were prospectively studied. The patients were divided into 3 groups of 17 patients, and the PELD learning curve was assessed by evaluating operating time, failure rate, complication rate, and 1-year reherniation rate. One-year clinical success rate was assessed by telephone interviews. The herniated disk was successfully removed by PELD in 47 patients. Four patients required subsequent open discectomy due to PELD failure. There were 2 minor complications. One year after surgery, clinical success was achieved in 42 of the 47 patients in whom PELD was initially successful, and reherniation developed in 5 patients. A significant reduction in operating time was observed after 17 patients had been treated (p = 0.0004). No significant differences were observed in terms of either failure rate or complication rate between the 3 groups. No significant differences were observed in terms of either the clinical success rate or the reherniation rate at 1 year after surgery. The PELD learning curve seems to be stable and acceptable with proper pre-PELD training.

Percutaneous endoscopic approach for highly migrated intracanal disc herniations by foraminoplastic technique using rigid working channel endoscope

STUDY DESIGN

A retrospective analysis of 59 patients operated for excision of soft highly migrated intracanal lumbar disc herniations by percutaneous endoscopic foraminoplasty.

OBJECTIVE

To describe a safe and effective percutaneous endoscopic technique for removal of migrated herniations and report the results on the basis of modified MacNab criteria.

SUMMARY OF BACKGROUND DATA

Migrated herniations pose a great challenge even for experienced endoscopic surgeons. These herniations are hidden from the endoscopic view by anatomic barriers like hypertrophied facet, inferior pedicle and foraminal ligaments rendering percutaneous endoscopic transforaminal lumbar discectomy (PELD) by conventional approach, difficult with high failure rate. Foraminoplasty, which means enlargement of foramen by undercutting ventral part of superior-facet, upper border of inferior pedicle along with ablation of foraminal ligament, can help us to address this issue.

METHODS

Fifty-nine patients with soft highly migrated herniations who underwent PELD with foraminoplasty under local anesthesia from January 2002 to June 2006 were analyzed retrospectively. Patients were evaluated by postoperative Visual Analog Scale for leg pain and Oswestry Disability Index scores. Outcomes were graded according to modified MacNab criteria.

RESULTS

Mean follow-up was 25.4 months. Mean visual analog scale score for radicular pain improved from 8.01 to 1.56, and mean Oswestry disability Index improved from 61.6 to 10.76. Based on modified MacNab criteria, 91.4% of patients experienced satisfactory outcome. Three patients had persistent leg pain after surgery. One patient underwent a repeat-PELD on next day and the other after 1 month. Both were relieved of symptoms. Third patient was subjected to open discectomy after 25 weeks from the first operation and showed improvement. Two patients had recurrent herniation at same level after 6 months; 1 patient underwent repeat PELD, and the other underwent open discectomy. Both patients had good results.

CONCLUSION

Foraminoplastic-PELD is safe and effective procedure for surgical treatment of soft migrated herniations. The results are comparable to results of open discectomy.