Abordaje mínimamente invasivo para hernias de disco extraforaminales: indicaciones, consideraciones quirúrgicas y resultados clínicos / Minimally Invasive Approach for Extraforaminal Herniated Discs: Indications, Surgical Considerations, and Clinical Outcomes

Introducción: Las hernias de disco extraforaminales representan entre el 0.3% y el 11.3% del total de las hernias de disco lumbares. Existen múltiples procedimientos quirúrgicos para el tratamiento de las mismas. Objetivo: Nuestro objetivo es presentar una serie de 5 casos de hernia de disco extraforaminal tratados mediante abordaje tubular mínimamente invasivo, describir la técnica quirúrgica utilizada y analizar la literatura pertinente. Pacientes y método: Cinco pacientes sin respuesta al tratamiento conservador con diagnóstico de hernia de disco extraforaminal, fueron sometidos a tratamiento quirúrgico mediante técnica tubular mínimamente invasiva durante el período de enero 2018-febrero 2019. Se analizaron datos demográficos e intraoperatorios. Los resultados clínicos fueron evaluados mediante la Escala Visual Analógica pre y postquirúrgico (EVA). Resultados: Cinco pacientes presentaron déficit neurológico y dolor lumbar que requirieron resolución quirúrgica. Todos los pacientes fueron dados de alta dentro de las 24 hs. postoperatorias. La escala de dolor disminuyó de forma estadísticamente significativa entre el momento pre y post quirúrgico (p=0.038). No se registraron fístulas ni infecciones. Conclusión: El abordaje tubular mínimamente invasivo fue una técnica efectiva para el tratamiento de hernias extraforaminales

ntroduction: Extraforaminal disc herniations represents 0.3-11.3% of every herniated lumbar discs. A variety of surgical procedures may be used for the treatment of this pathology. Objective: The aim of this study is to present 5 cases of extraforaminal herniated discs treated via a minimally invasive spine surgery using tubular retractors, to describe the surgical technique and to analyze the literature on this subject. Pacients and method: 5 patients who did not get better with conservative treatment were operated using minimally invasive tubular retractors between January 2018 and February 2019. Demographic variables and intraoperative data were analyzed. Clinical outcomes was evaluated using the Analog Visual Scale (VAS). Results: Five patients who presented neurological deficit and low back pain were operated. Every patients was discharged before 24 hours postoperative. VAS significantly decrease comparing pre and postoperative (p=0.038). No cerebrospinal fluid leaks or infections were recorded. Conclusion: The use of minimally invasive tubular retractors is an effective technique for treating extraforaminal herniated discs.

Far lateral lumbar disc extrusion in a dachshund dog / 대한수의학회지

A 6-year-old Dachshund was presented with acute, non-localized pain without neurological dysfunction. Radiography revealed multiple calcifications of intervertebral discs and narrowing of disc space in the thoracolumbar region. Computed tomography and magnetic resonance imaging revealed calcified disc-like material entrapped in the left extraforaminal area and showed a displaced nerve root. Fenestration and removal of the extruded disc material were performed in a routine manner. Histopathological examination showed degenerative disc materials with severe calcification both in the nucleus pulposus and around the annulus fibrosis. Based on imaging, surgical, and histopathologic results, the dog was diagnosed with far lateral lumbar disc extrusion.

Extraforaminal Extrusion of Intervertebral Disc Misdiagnosed as Neurogenic Tumor: a Case Report

A 55-year-old male presented with dysesthesia of the right anteromedial thigh. A magnetic resonance image revealed a globular mass at the right extraforaminal area of the L3/4 level. Based on the diagnosis of neurogenic tumor, surgical excision was performed. The surgical impression and pathology confirmed extrusion of intervertebral disc. In a retrospective review of the magnetic resonance image, we noticed a fibrillary pattern directed from the intervertebral disc space to the lesion, and disrupted annulus fibrosus and indentation caused by the ring apophysis. We suggest aforementioned features, indicative of intervertebral disc lesions, to be checked when interpreting mass lesions around the intervertebral foramen.

Extraforaminal Extrusion of Intervertebral Disc Misdiagnosed as Neurogenic Tumor: a Case Report

A 55-year-old male presented with dysesthesia of the right anteromedial thigh. A magnetic resonance image revealed a globular mass at the right extraforaminal area of the L3/4 level. Based on the diagnosis of neurogenic tumor, surgical excision was performed. The surgical impression and pathology confirmed extrusion of intervertebral disc. In a retrospective review of the magnetic resonance image, we noticed a fibrillary pattern directed from the intervertebral disc space to the lesion, and disrupted annulus fibrosus and indentation caused by the ring apophysis. We suggest aforementioned features, indicative of intervertebral disc lesions, to be checked when interpreting mass lesions around the intervertebral foramen.

Three-Years Outcome of Microdiscectomy via Paramedian Approach for Lumbar Foraminal or Extraforaminal Disc Herniations in Elderly Patients over 65 Years Old

OBJECTIVE: Lumbar foraminal or extraforaminal disc herniations (FEFDH) have unusual clinical features and higher incidence in elderly patients compared to usual intraspinal canal disc herniations. We evaluated the efficacy of microdiscectomy via paramedian approach for lumbar FEFDH in elderly patients over the age of 65. METHODS: Retrospective study was performed in 68 patients over the age of 65 (23 male and 45 female patients; 71.46±3.87 years) who underwent microdiscectomy via paramedian approach for unilateral lumbar FEFDH causing sciatica. The radiological factors including degree of slippage, presence of instability, disc height, and degree of disc degeneration; pain and functional status by the means of visual analogue scale score, Oswestry Disability Index score, and Macnab classification were analyzed preoperatively and during the postoperative follow-up period of 3 years to evaluate the efficacy of the surgical treatment. RESULTS: Pain and functional status improved according to short- and long-term follow-up evaluations after surgery. Radiological changes following surgery, which can be understood as structural deteriorations and deformations, did not represent patient condition. Nine patients underwent additional surgery due to sustained or recurring leg pain of aggravation of back pain, and fusion surgery was required for 3 patients. Degree of preoperative slippage was the only statistically significant factor related to additional surgery (p<0.05). CONCLUSION: Microdiscectomy via paramedian approach for FEFDH may be a good surgical alternative in elderly patients. Radiological changes after surgery did not show a concordance with patients' actual functional status. The excessive preoperative slippage tended to lead to unfavorable result after surgery and was associated with additional surgery.

Usefulness of the ProSet MRI for Diagnosis of the Extraforaminal Disc Herniation

STUDY DESIGN: This is a retrospective study. OBJECTIVES: The purpose of this study is to confirm the clinical usefulness of utilizing ProSet imaging for checking the nerve root compression and swelling in extraforaminal disc herniation. SUMMARY OF LITERATURE REVIEW: Diagnosing extraforaminal disc herniations can be neglected with using a conventional MRI. MATERIALS AND METHODS: A retrospective analysis was performed on 25 patients, who underwent both conventional & Principles of the selective excitation technique (ProSet) MR imaging for the evaluation of extraforaminal disc herniation, from April 2008 to October 2010. Radiographic analysis was based on the notion that the degree of nerve root compression and swelling was decided by Pfirrmann's classification. RESULTS: Severe compression in the ProSet 3D rendering image was observed in 21 subjects, as compared with 8 subjects in the conventional axial image. Especially, nothing was ever detected in the conventional sagittal image. Severe compression in the ProSet 3D rendering image was observed in 4 subjects, while their nerve root compression was not clear in the conventional axial image. Severe compression and severe swelling in the ProSet 3D & coronal image was observed in 15 subjects, while their nerve root compression was none or not clear in the conventional sagittal image. The swelling degree of the ProSet coronal image turned out bigger than the swelling degree of conventional axial image, and the signal intensity change was also obvious. CONCLUSIONS: ProSet imaging is regarded useful to investigate the symptom triggering nerves, because ProSet image not only observes better nerve root compression, but also identifies the swelling degree more easily than that of the conventional magnetic resonance imaging (MRI).

Usefulness of Three Dimensional Proset MR Images for Diagnosis of Symptomatic L5-S1 Foraminal and Extraforaminal Stenosis

OBJECTIVE: To suggest a new useful diagnostic technique, principles of the selective excitation technique-magnetic resonance images (Proset-MRI), and to know the precise radiologic findings that can prove symptomatic foraminal and extraforaminal stenosis at L5-S1. METHODS: Nineteen patients with symptomatic L5-S1 stenosis were checked by Proset-MRI. Four patients were performed decompressive surgery and 15 patients were performed selective nerve root block (SNRB) at L5. The pain scale of patients was checked by Visual Analogue Scale (VAS) scores at the pre- and post-treatment state. RESULTS: Proset-MRI findings of patients with symptomatic stenosis are root swelling (RS) and indentation. The comparisons with VAS scores had a meaningful statistical result at each RS (p<0.01) and indentation (p<0.01). However, the findings of RS combined with indentation lacked statistical significance (p=0.0249). In addition, according to a comparison with the treatment modalities, reducing of VAS scores had statistical meaningful significance in decompressive surgery cases (p<0.01), and also in SNRB cases (p<0.01) after a 3-month follow-up period. CONCLUSION: The three dimensional Proset-MRI is very useful and sensitive technique to diagnose the symptomatic foraminal and extraforaminal stenosis at L5-S1.

Differentiation between Symptomatic and Asymptomatic Extraforaminal Stenosis in Lumbosacral Transitional Vertebra: Role of Three-Dimensional Magnetic Resonance Lumbosacral Radiculography

OBJECTIVE: To investigate the role of lumbosacral radiculography using 3-dimentional (3D) magnetic resonance (MR) rendering for diagnostic information of symptomatic extraforaminal stenosis in lumbosacral transitional vertebra. MATERIALS AND METHODS: The study population consisted of 18 patients with symptomatic (n = 10) and asymptomatic extraforaminal stenosis (n = 8) in lumbosacral transitional vertebra. Each patient underwent 3D coronal fast-field echo sequences with selective water excitation using the principles of the selective excitation technique (Proset imaging). Morphologic changes of the L5 nerve roots at the symptomatic and asymptomatic extraforaminal stenosis were evaluated on 3D MR rendered images of the lumbosacral spine. RESULTS: Ten cases with symptomatic extraforaminal stenosis showed hyperplasia and degenerative osteophytes of the sacral ala and/or osteophytes at the lateral margin of the L5 body. On 3D MR lumbosacral radiculography, indentation of the L5 nerve roots was found in two cases, while swelling of the nerve roots was seen in eight cases at the exiting nerve root. Eight cases with asymptomatic extraforaminal stenosis showed hyperplasia and degenerative osteophytes of the sacral ala and/or osteophytes at the lateral margin of the L5 body. Based on 3D MR lumbosacral radiculography, indentation or swelling of the L5 nerve roots was not found in any cases with asymptomatic extraforaminal stenosis. CONCLUSION: Results from 3D MR lumbosacral radiculography Indicate the indentation or swelling of the L5 nerve root in symptomatic extraforaminal stenosis. Based on these findings, 3D MR radiculography may be helpful in the diagnosis of the symptomatic extraforaminal stenosis with lumbosacral transitional vertebra.

The Role of Computed Tomography in the Presurgical Diagnosis of Foraminal Entrapment of Lumbosacral Junction

OBJECTIVE: On the basis of preoperative computed tomography (CT) scans, we studied the change of the size of anterior primary division (APD) of the L5 spinal root in the presence of foraminal/extraforaminal entrapment of the L5 spinal root. METHODS: Two independent radiologists retrospectively reviewed the preoperative CT scans of 27 patients treated surgically and compared the sizes of the APDs on bilateral L5 spinal roots. If one side APD size was larger than the other side APD size, it was described as left or right "dominancy" and regarded this as "consensus (C)" in case that there was a consensus between the larger APD and the location of sciatica, and regarded as "non-consensus (NC)" in case that there was not a consensus. Oswestry Disability Index (ODI) scores were used for preoperative and postoperative evaluation. RESULTS: On CT scans, twenty-one (77%) of 27 patients were the consensus group (APD swelling) and 6 (22%) were a non-consensus group (APD no swelling). In 9 patients with acute foraminal disc herniations, asymmetric enlargement of the APD on L5 spinal root was detected in all cases (100%) and detected in 11 (64%) of 17 patients with stenosis. Preoperative ODI score was 75-93 (mean 83) and postoperative ODI scores were improved to 13-36 (mean 21). The mean follow-up period was 6 months (range, 3-11 months). CONCLUSION: An asymmetric enlargement of the APD on L5 spinal root on CT scans is meaningfully associated with a foraminal or extraforaminal entrapment of the L5 spinal root on the lumbosacral junction.

Reliability of MRI findings for Symptomatic Extraforaminal Disc Herniation in Lumbar Spine

STUDY DESIGN: A retrospective study PURPOSE: This study examined the reliability of the MRI findings in detecting symptomatic extraforaminal disc herniation in the lumbar spine. OVERVIEW OF LITERATURE: There are no reports of the characteristics and reliable MRI findings of extraforaminal disc herniation. METHODS: Thirty age-and gender-matched asymptomatic volunteers and 30 patients with symptomatic extraforaminal disc herniation, who underwent surgery between March 2006 and Dec 2008, were enrolled in this study. All subjects underwent spinal MRI. The following parameters were evaluated: the presence or absence of focal eccentricity of the disc, change in the diameter of the nerve root, and displacement of the nerve root at the extraforaminal zones. Radiologic studies were reviewed blindly and independently by 3 spine surgeons. RESULTS: The overall agreement in determining the presence or absence of a symptomatic extraforaminal disc herniation between the three reviewers was 89.4% (161/180). The consensus showed focal eccentricity of the disc in 33 cases (55%), a change in diameter in the nerve root in 31 cases (51.7%), and a displacement of the nerve root in 23 cases (38.3%). An assessment of the paired intraobserver and interobserver reliability revealed mean Kappa statistics of 0.833 and 0.667 for focal eccentricity of the disc, 0.656 and 0.556 for a change in the diameter of the nerve root, and 0.669 and 0.020 for a displacement of the nerve root, respectively. CONCLUSIONS: There are three possible MRI findings that can be used to determine the presence or absence of symptomatic extraforaminal disc herniation. Among these MRI findings, focal eccentricity of the disc was found to be the most reliable.

Morphologic Changes of L5 Root at Coronal Source Images of MR Myelography in Cases of Foraminal or Extraforaminal Compression

OBJECTIVE: Two findings easily found at coronal source images of MR myelography (MRM) were evaluated : dorsal root ganglion (DRG) swelling and running course abnormality (RCA) of L5 exiting root at foramen or extraforamen. We tried to find the sensitivity of each finding when root was compressed. METHODS: From 2004 July to 2006, one hundred and ten patients underwent one side paraspinal decompression for their L5 root foraminal or extraforaminal compression at L5-S1 level. All kinds of conservative treatments failed to improve leg symptom for several months. Before surgery, MRI, CT and MRM were done. Retrospective radiologic analysis for their preoperative MRM coronal source images was done to specify root compression sites and L5 root morphologic changes. RESULTS: DRG swelling was found in 66 (60%) of 110 patients. DRG swelling has statistically valuable meaning in foraminal root compression (chi-square test, p < 0.0001). Seventy-two (66%) in 110 patients showed abnormal alteration of running course. Abnormal running course has statistically valuable meaning in foraminal or extraforaminal root compression (chi-square test, p < 0.0001). CONCLUSION: Three-dimensional MRM provides precise thin sliced coronal images which are most close to real operative views. DRG swelling and running course abnormality of L5 exiting root are two useful findings in diagnosing L5 root compression at L5-S1 foramen or extraforamen. MRM is thought to provide additional diagnostic accuracy expecially in L5-S1 foraminal and extraforaminal area.

Effect of Intensive Conservative Treatment on Extraforaminal Lumbar Disc Herniations - 1 Year Prospective Follow-up Study

OBJECTIVE: To evaluate the outcomes of intensive conservative treatment on extraforaminal lumbar disc herniations. METHOD: Twenty five patients with extraforaminal lumbar disc herniations with symptomatic radicular pain were included. Under fluoroscopic guidance, 40 mg of triamcinolone was infused around the nerve root after provocation of patient's usual radicular pain. Lumbosacral dynamic stabilization exercise, thermal and electrical therapy, and education of posture correction were added. The clinical outcomes were measured by visual analogue scale (VAS) and Oswestry disability index (ODI) before treatment, one, three, six, and twelve months after the treatment. After twelve months, patients' satisfaction was classified to four categories: excellent, good, fair, or poor. Four patients were dropped out. RESULTS: Follow-up VAS and ODI significantly decreased since post-treatment one month (p<0.0001). The average score of VAS for lower extremity and back pain reduced significantly from 6.6, 4.5 at pretreatment to 1.5, 1.9 at 12 months post-treatment, respectively (p<0.0001). The averages of ODI reduced significantly from 65.4% at pretreatment to 25.4% at post-treatment 12 months (p<0.0001). In patients' satisfaction, seventeen patients (81.0%) were recorded as excellent or good after post-treatment 12 months. CONCLUSION: Intensive conservative treatment was effective on patients who underwent extraforaminal lumbar disc herniation. Pain relief and functional improvement sustained for 12 months.

Microdecompression for Extraforaminal L5-S1 Disc Herniation; The Significance of Concomitant Foraminal Disc Herniation for Postoperative Leg Pain

OBJECTIVE: To analyze the relationship of concomitant foraminal lumbar disc herniation (FLDH) with postoperative leg pain after microdecompression for extraforaminal lumbar disc herniation (EFLDH) at the L5-S1 level. METHODS: Sixty-five patients who underwent microdecompression for symptomatic EFLDH at the L5-S1 level were enrolled. According to the severity of accompanying FLDH, EFLDH was classified into four categories (Class I : no FLDH; Class II : mild to moderate FLDH confined within a lateral foraminal zone; Class III : severe FLDH extending to a medial foraminal zone; Class IV : Class III with intracanalicular disc herniation). The incidence of postoperative leg pain, dysesthesia, analgesic medication, epidural block, and requirement for revision surgery due to leg pain were evaluated and compared at three months after initial surgery. RESULTS: The incidences of postoperative leg pain and dysesthesia were 36.9% and 26.1%, respectively. Pain medication and epidural block was performed on 40% and 41.5%, respectively. Revision surgery was recommended in six patients (9.2%) due to persistent leg pain. The incidences of leg pain, dysesthesia, and requirement for epidural block were higher in Class III/IV, compared with Class I/II. The incidence of requirement for analgesic medication was significantly higher in Class III/IV, compared with Class I/II (p=0.02, odds ratio=9.82). All patients who required revision surgery due to persistent leg pain were included in Class III/IV. CONCLUSION: Concomitant FLDH seems related to postoperative residual leg pain after microdecompression for EFLDH at the L5-S1 level.

Usefulness of Coronal MR Image in Diagnosis of Foraminal and Extraforaminal Disc Herniation / 대한척추외과학회지

STUDY DESIGN: This is a retrospective study OBJECTIVES: The coronal MR images were carefully evaluated to document the efficacy of diagnosing foraminal and extraforaminal disc herniations. SUMMARY OF LITERATURE REVIEW: Extraforaminal disc herniations constitute 1~11.7% of all disc herniations. The diagnosis of it demands great caution because it must be distinguished from intraspinal canal disc herniation. Diagnosing extraforaminal disc herniations can be neglected with using ordinary diagnostic methods. MATERIALS AND METHODS: A retrospective analysis was performed on 24 patients, (26 cases) that underwent lumbar spine MRI, with the T2 coronal images, for the evaluation of disc herniations from March 2006 to March 2007. Every MRI image of each patient who had foraminal or extraforaminal disc herniations was graded according to the Pfirrmann's classification of diagnostic efficacy by two spinal surgery specialists and two radiology specialists. RESULTS: There were 13 cases of foraminal disc herniation and 13 cases of extraforaminal disc herniation in all 26 cases that were diagnosed by MRI. The coronal and axial images were more effective than the sagittal images for the discrimination of a compressed root. Especially, for the extraforaminal disc herniation, all of the coronal images were graded as grade 3; on the other hand, all of the sagittal images were not helpful for the assessment and the axial images were graded as grade 2 for 38.5% of the and as grade 3 for 61.5%. So, the coronal images were most effective for making the diagnosis of extraforaminal disc herniation and this was statistically significant (p<0.05). CONCLUSION: For the accurate discrimination of the location and the grading of foraminal and extraforaminal disc herniation, MRI, and especially the coronal images, is an effective and useful method in addition to conducting a physical examination.

The Clinical Comparison between Open Surgery and Percutaneous Endoscopic Lumbar Discectomy in Extraforaminal Lumbar Disc Herniation

OBJECTIVE: The objective of this study is to evaluate and compare the clinical results between classical open surgery and percutaneous endoscopic lumbar discectomy(PELD) in cases of extraforaminal lumbar disc herniation. METHODS: We obtained the clinical data from 47 patients with extraforaminal lumbar disc herniations who underwent the open paramedian muscle-splitting approach or percutaneous endoscopic lumbar discectomy(PELD) between January 2001 and February 2004. This study consisted of patients with soft disc extraforaminal herniations. The patients were assessed with the visual analogue scale(VAS) and MacNab's criteria before surgery, just before discharge, and postoperative 1 year. RESULTS: There were 25 cases in the open surgery group and 22 cases in the PELD group. The average operating time was 78+/-36.71 min in the PELD group and 110+/-29.68 min in the open surgery group. The mean hospital stay was 2.73+/-2.62 days in the PELD group and 7.68+/-2.59 days in the open surgery group. VAS decreased from 8.34+/-0.66 to 1.29+/-2.27 in the PELD group and from 8.40+/-1.40 to 1.70+/-1.72 in the open surgery group at the one-year follow-up. The success rate of PELD was 86.4%, compared with 80.0% for open surgery. However, there were no statistically significant difference between two groups for success rate and VAS. CONCLUSION: Although the success rates were similar in both groups, PELD is less invasive, faster, and safe procedure than open surgery for extraforaminal disc herniation in selected patients.

Clinical Analysis of Extraforaminal Entrapment of L5 in the Lumbosacral Spine

OBJECTIVE: Here we describe a microsurgical method for decompression and the radiological findings of the extraforaminal entrapment of the L5 spinal nerve. METHODS: The authors reviewed the clinical and neurodiagnostic findings, surgical management, and outcomes in 53 patients with extraforaminal entrapment of L5 who had been successfully decompressed via a microsurgical paramedian tangential approach. A total of 28 women and 25men ranging in age from 54 to 73(mean age 65 years). All patients had uni- or bilateral leg pain due to extraforaminal entrapment of L5 in the lumbosacral spine. The mean follow-up period was 9 months (range 3-15 months). RESULTS: Pain was measured by the Numerical Rating Scale. The function of back was assessed by the Oswestry Disability Index score, and the patient satisfaction was evaluated by the North American Spine Society Outcome Questionnaire. Relief of back pain was obtained for all patients immediately after surgery. The mean Numerical Rating Scale improved from 8.2 before the surgery to 1.7 after the surgery (P<0.0001). The mean ODI score improved from 74.6 before the surgery to 15.3 after the surgery (P<0.0001). Overall, excellent and good result were achieved in 27(51%) and 23(43%) at the last follow-up examination. There was no complications related to the surgery, nor was any spinal instability was detected. The parasagittal T-1 weighted magnetic resonance images showed foraminal stenosis with the circumferential loss of the perineural fat signal at L5-1 level in 23 of 53(43%) patients. Radiological and operating finding showed narrowing of the extraforaminal tunnel that resulted from the annulus bulging in 36 patients(68%), disc protrusion or rupture in 17 patients(30%) and osteophytes of the vertebral body in 39 patients(74%). CONCLUSION: The paramedian tangential approach is a safe, effective procedure that avoids the risk of secondary spinal instability. This study showed that the major causes of the extraforaminal nerve root entrapment in the lumbosacral spine are the bulged annulus, the disc protrusion and osteophytes. The major pathognomonic cause of the extraforaminal L5 nerve entrapment was the bulged annulus fibrosus with the osteophytes.

Paramedian Tangential Approach for the Lumbosacral Extraforaminal Disc Herniations

OBJECTIVE: Even though paramedian approach has advantages over other surgical approaches for lumbar extraforaminal disc herniations, this approach has limitations for lumbosacral extraforaminal disc herniations because of narrow operative bony window. This case report is presented to describe the modified paramedian tangential approach for lumbosacral extraforaminal disc herniations(focused on surgical technique and efficacy of this approach). METHODS: Two patients with lumbosacral extraforaminal disc herniations were operated using paramedian tangential approach. RESULTS: Using this new approach, lumbosacral extraforaminal disc herniations could be operated with safety and minimal amount of nerve root manipulation. CONCLUSION: This paramedian tangential approach seems to be one of good surgical options for lumbosacral extraforaminal disc herniations.