Microscopic resection of lumbar intraspinal tumor through keyhole approach: A clinical study of 54 cases / 北京大学学报(医学版)

OBJECTIVE@#To explore the feasibility and key technology of microscopic resection of lumbar intraspinal tumor through microchannel keyhole approach.@*METHODS@#The clinical features, imaging characteristics and surgical methods of 54 cases of lumbar intraspinal tumor which were microscopically operated by microchannel from February 2017 to September 2019 were reviewed and analyzed. There were 8 cases of extradural tumor, 3 cases of extra-and intradural tumor and 43 cases of subdural extramedullary tumor (including 3 cases of ventral spinal tumor). The tumors were 0.5-3.0 cm in diameter. The clinical symptoms included 49 cases of pain in the corresponding innervation area, 5 cases of sensory disturbance (numbness) at or below the tumor segment, 7 cases of limb weakness and 2 cases of urination and defecation dysfunction.@*RESULTS@#In the study, 37 tumors were resected through hemilaminectomy, 14 tumors were resected through interlaminar fenestration, 3 tumors were resected through hemilaminectomy or interlaminar fenestration combined with facetectomy of medial 1/4 facet. All of the 54 tumors were totally resected. The operation time was 75-135 min, with an average of 93.3 min. The postoperative hospital stay was 4-7 days, with an average of 5.7 days. Postoperative pathology included 34 cases of schwannoma, 4 cases of meningioma, 9 cases of ependymoma, 1 case of enterogenous cyst, 5 cases of teratoma/epidermoid/dermoid cyst, and 1 case of paraganglioma. No infection or cerebrospinal fluid leakage was found after operation. No neurological dysfunction occurred except 1 case of urination dysfunction and 4 cases of limb numbness. The follow-up period ranged from 3 to 33 months with an average of 14.4 months. Five patients with new onset symptoms returned to normal. The pain symptoms of 49 patients were completely relieved; 4 of 5 patients with hypoesthesia recovered completely, the other 1 patient had residual mild hypoesthesia; 7 patients with limb weakness, and 2 patients with urination and defecation dysfunction recovered to normal. No spinal instability or deformity was found, and no recurrence or residual tumors were found. According to McCormick classification, they were of all grade Ⅰ.@*CONCLUSION@#The lumbar intraspinal extramedullary tumors within two segments (including the ventral spinal tumors) can be totally resected at stage Ⅰ through microchannel keyhole approach with appropriate selection of the cases. Microchannel technique is beneficial to preserve the normal structure and muscle attachment of lumbar spine, and to maintain the integrity and stability of lumbar spine.

The need for opioid in the postoperative analgesia of dogs undergoing hemilaminectomy due to intervertebral disc extrusion

ABSTRACT: The aim of this study was to evaluate the postoperative analgesic effect of protocols with and without the opioid methadone in dogs with intervertebral disc extrusion undergoing decompressive surgery. Sixteen paraplegic dogs with preserved nociception underwent hemilaminectomy/disc fenestration and were randomly assigned to two groups. The analgesic protocol consisted of methadone, meloxicam and dipyrone in Group I (G1), and meloxicam and dipyrone in Group II (G2). The animals were blindly assessed by two observers, using the visual analogue scale (VAS) and the short-form Glasgow Composite Measure Pain Scale (CMPS-SF). Assessments occurred every 2 hours during first 24 hours post-surgery, and every 4 hours afterwards. There was no statistical difference among groups regarding pain scores or analgesic rescues. Both analgesic protocols provided analgesia in the initial 48 hours postoperatively, demonstrating that opioids are not necessary in the postoperative period of dogs undergoing hemilaminectomy and disc fenestration.

RESUMO: O objetivo deste estudo foi avaliar a analgesia pós-operatória de protocolos com e sem o opioide metadona em cães com extrusão de disco intervertebral submetidos à descompressão cirúrgica. Dezesseis cães paraplégicos com presença de nocicepção foram submetidos à hemilaminectomia/fenestração de disco e distribuídos aleatoriamente em dois grupos. No Grupo I (G1), o protocolo analgésico consistiu em metadona, meloxicam e dipirona e, no Grupo II (G2), por meloxicam e dipirona. Os pacientes foram avaliados de maneira cega por dois avaliadores, com base na escala visual analógica (EVA) e na escala simplificada composta de dor de Glasgow (CMPS-SF). As avaliações ocorreram a cada 2 horas durante as primeiras 24 horas de pós-operatório e, por mais 24 horas, a cada 4 horas. Não houve diferença estatística entre os grupos avaliados em relação à escores de dor e nem a necessidade de resgate analgésico. Ambos os protocolos promoveram analgesia nas 48 horas iniciais de pós-operatório, demonstrando não haver a necessidade do uso de opioide em cães submetidos à hemilaminectomia e fenestração de disco.

The need for opioid in the postoperative analgesia of dogs undergoing hemilaminectomy due to intervertebral disc extrusion / A necessidade de opioide na analgesia pós-operatória de cães submetidos à hemilaminectomia devido à extrusão do disco intervertebral

The aim of this study was to evaluate the postoperative analgesic effect of protocols with and without the opioid methadone in dogs with intervertebral disc extrusion undergoing decompressive surgery. Sixteen paraplegic dogs with preserved nociception underwent hemilaminectomy/disc fenestration and were randomly assigned to two groups. The analgesic protocol consisted of methadone, meloxicam and dipyrone in Group I (G1), and meloxicam and dipyrone in Group II (G2). The animals were blindly assessed by two observers, using the visual analogue scale (VAS) and the short-form Glasgow Composite Measure Pain Scale (CMPS-SF). Assessments occurred every 2 hours during first 24 hours post-surgery, and every 4 hours afterwards. There was no statistical difference among groups regarding pain scores or analgesic rescues. Both analgesic protocols provided analgesia in the initial 48 hours postoperatively, demonstrating that opioids are not necessary in the postoperative period of dogs undergoing hemilaminectomy and disc fenestration.(AU)

O objetivo deste estudo foi avaliar a analgesia pós-operatória de protocolos com e sem o opioide metadona em cães com extrusão de disco intervertebral submetidos à descompressão cirúrgica. Dezesseis cães paraplégicos com presença de nocicepção foram submetidos à hemilaminectomia/fenestração de disco e distribuídos aleatoriamente em dois grupos. No Grupo I (G1), o protocolo analgésico consistiu em metadona, meloxicam e dipirona e, no Grupo II (G2), por meloxicam e dipirona. Os pacientes foram avaliados de maneira cega por dois avaliadores, com base na escala visual analógica (EVA) e na escala simplificada composta de dor de Glasgow (CMPS-SF). As avaliações ocorreram a cada 2 horas durante as primeiras 24 horas de pós-operatório e, por mais 24 horas, a cada 4 horas. Não houve diferença estatística entre os grupos avaliados em relação à escores de dor e nem a necessidade de resgate analgésico. Ambos os protocolos promoveram analgesia nas 48 horas iniciais de pós-operatório, demonstrando não haver a necessidade do uso de opioide em cães submetidos à hemilaminectomia e fenestração de disco.(AU)

Experimental Study of Hemilaminectomy, Total Laminectomy and Recapping laminoplasty of Cervical Spine in Sheep / 医用生物力学

Objective To study the effect of hemilaminectomy, total laminectomyand recapping laminoplasty on stability of the cervical spine. Methods Fourteen fresh adult sheep cervical spine specimens were divided into two groups, with 7 cases in each group. Each specimen was applied with a pure moment load of 3.0 N·m under flexion/extension, left/right lateral bending, and left/right axial rotation. The range of motion (ROM) and neutral zone (NZ) of specimens were measured. In the first group, the ROMs and NZs of the specimens were measured and compared under the intact state, C5 hemilaminectomy state and C4-6 hemilaminectomy state respectively. In the second group, the ROMs and NZs of specimens under the intact state, C4-6 total laminectomy state and C4-6 recapping laminoplasty state were measured and compared. Results There were no significant differences in ROMs and NZs between C5 hemilaminectomy state and C4-6 hemilaminectomy state compared with the intact state (P<0.05). Compared with the intact state, ROMs of the specimens were significantly increased during flexion and extension under C4-6 laminectomy state and C4-6 recapping laminoplasty state (P<0.05). In addition, compared with the C4-6 laminectomy state, ROMs of the specimen were significantly decreased only during extension unde C4-6 recapping laminoplasty state (P<0.05), while no significant differences were found in ROMs between total laminectomy and laminoplasty under other loads. Conclusions With hemilaminectomy, ROMs and NZs of the cervical spine did not increase significantly, and stability of the cervical spine was not affected. With C4-6 total laminectomy, ROMs and NZs during flexion and extension increased significantly, and stability of the cervical spine was affected. Recapping laminoplasty did not significantly improve stability of the cervical spine with total laminectomy.

Abordaje mínimamente invasivo para el tratamiento de tumores espinales intradurales extramedulares / Minimally invasive approach for the treatment of extramedullary intradural spinal tumors

Introducción: Describir la técnica de abordaje mínimamente invasiva para el tratamiento de tumores intradurales extramedulares en los diferentes segmentos espinales. Material y Métodos: Se detallan la planificación, posicionamiento, marcación, pasos técnicos del abordaje mínimamente invasivo, exéresis lesional y cierre de lesiones ID-EM a nivel cervical, dorsal, lumbar y sacro. Se proporcionan recomendaciones para descomplejizar maniobras quirúrgicas, acortar el tiempo operativo y evitar potenciales complicaciones. Conclusiones: El abordaje MISS es una opción segura y eficaz para el tratamiento quirúrgico de determinados tumores ID-EM.

Objective: To describe the technique of minimally invasive approach for the treatment of intradural extramedullary tumors in the different spinal segments. Material and Methods: The planning, positioning, skin marking, technical steps of the minimally invasive approach, lesion resection, and closure of ID-EM lesions at the cervical, dorsal, lumbar and sacral levels are detailed. Recommendations are provided to simplify surgical maneuvers, shorten operative time and avoid potential complications. Conclusions: The MIS approach is a safe and effective option for the surgical treatment of certain ID-EM tumors.

Consequences of intraoperative spinal cord manipulation in dogs with thoracolumbar intervertebral disc extrusion / Consequências da manipulação medular intraoperatória em cães com extrusão intervertebral de disco toracolombar

The objective of the present study was to evaluate if extradural contact during hemilaminectomy would cause neurological deterioration in the early and/or late postoperative period in dogs with intervertebral disc extrusion. Nineteen dogs with thoracolumbar intervertebral disc extrusion underwent hemilaminectomy for spinal cord decompression and removal of extruded disc material. Meningeal contacts during surgery were quantified. Paraplegia (with nociception) and paraparesis were observed in 11/19 and 8/19 of dogs, respectively, before surgery. At the end of our study, only two (2/19) had paraplegia and one (1/19), paraparesis. There were more extradural contacts when extruded intervertebral disc material was at a ventrolateral position. Extradural contacts during surgery had no influence on neurological progression nor on time to recovery of motor function. Immediately (24 and 48 hours) after surgery, 13/19 dogs had the same neurological stage before surgery. At 7 and 90 days, 13/19 and 17/19 dogs, respectively, showed neurological improvement, compared with their preoperative stage. There was no influence of the number of extradural contacts on neurological recovery. These findings indicate that a careful inspection of the vertebral canal for removal of as much extruded disc material as possible does not cause neurologic deterioration.(AU)

O presente trabalho teve como objetivo avaliar se contatos extradurais durante hemilaminectomia em cães com extrusão de disco intervertebral causariam piora neurológica no pós-operatório imadiato e/ou tardio. Dezenove cães com extrusão toracolombar de disco intervertebral foram submetidos à hemilaminectomia para descompressão medular e remoção do material extruso. Durante o procedimento cirúrgico, os contatos meningomedulares foram quantificados. Antes da cirurgia, 11/19 cães apresentavam paraplegia (com nocicepção) e 8/19 cães, paraparesia. Ao fim do estudo, apenas dois cães (2/19) mostravam paraplegia com dor profunda e um (1/19), paraparesia. Observou-se maior quantidade de contatos extradurais quando o material discal extruso encontrava-se em posição ventrolateral. Os contatos extradurais não mostraram influência estatística na evolução neurológica dos animais, bem como no tempo de recuperação das funções motora. Vinte e quatro e 48 horas após a cirurgia, 13/19 cães apresentavam o mesmo grau neurológico de antes da cirurgia. Após sete e 90 dias de pós-operatório, 13/19 e 17/19 demonstraram melhora neurológica em comparação com o pré-operatório, respectivamente. A quantidade de contatos extradurais não influenciou na recuperação neurológica dos cães. Esses achados indicam que uma inspeção minuciosa do canal vertebral pode ser recomendada, a fim de remover o máximo de material discal extruso, evitando-se piora neurológica por compressão medular.(AU)

Comparative Study of the Unilateral Hemilaminectomy Approach and the Total Laminectomy Approach in the Treatment of Subdural Extr-amedullary Tumors / 医学研究杂志

Objective To compare the clinical results of the unilateral hemilaminectomy approach and the total laminectomy ap-proach in the treatment of subdural extramedullary tumors.Methods One hundred cases with subdural extramedullary tumors from Sep-tember 2010 to September 2013 in the General Hospital of Ningxia Med.Univ.underwent surgery intervention were prospective analyzed. Among them,50 cases( the observation group) received tumor resection by the unilateral hemilaminectomy approach,and another 50 cases ( the control group) received the treatment by the total laminectomy approach.All received electrophysiological monitoring in the opera-tion.Operation time,intraoperative bleeding,postoperative hospitalization duration and postoperative recurrence rate in 6 months to 1 year etc.were recorded and compared.Results Operation time,intraoperative bleeding,postoperative hospitalization duration and postoperative fields time in the the observation group were less than the control group(P<0.05).There was no significant difference in curative effect aspects.In the postoperative follow-up(6 months to 1 year) ,the spinal instability cases in the observation group(0 case) was significantly less than the control group (6 cases).Conclusion Compared with the total laminectomy approach,the unilateral hemilaminectomy ap-proach in the treatment of subdural extramedullary tumors has more advantages as follows:better curative effect, smaller trauma, quicker recovery, fewer complications, great maintenance in spinal mobility and stability etc.

Establishment of a rat model of lumbar nerve root compression via modified unilateral hemilaminectomy approach / 中国实验动物学报

Objective To explore the characteristics and advantages of the rat model of lumbar nerve root com -pression established via modified hemilaminectomy approach .Methods Forty Sprague Dawley ( SD) rats were randomly divided into two groups ( experimental group and control group ) for establishing a rat model of lumbar nerve root compres-sion.Modified hemilaminectomy apprpoach was used in the experimental group , while total laminectomy was applied in the control group.Duration of operation, estimated blood loss, wound healing status, postoperative mortality, motor function of the lower extremities , pathological changes and the gray level of cytoplasmic TNF-αand IL-1 expression were observed to e-valuate the characteristics and reliability of the two operation approaches in establishing a rat model of lumbar nerve root compression.Results Compared with the control group , duration of operation , estimated blood loss , wound healing sta-tus, postoperative mortality were significantly better in the experimental group (P<0.01), whereas there was non-signifi-cant difference between two groups with regard to motor function of the lower extremities , pathological changes and gray lev-el of the cytoplasmic expression of TNF-αand IL-1 between the two groups .Moreover, the soft tissue structural alterations were reduced in the experimental group , which might be helpful for the rat postoperative rehabilitation .Conclusions Modified hemilaminectomy approach is a reliable alternative method for establishing a rat model of lumbar nerve root com -pression, which is beneficial to shorten the operative time , improve wound healing status , reduce estimated blood loss and damages of soft tissue , and decrease mortality rate .Moreover , this modified method is more consistent with the principles of animal ethics .

The application of hemilaminectomy approach in intraspinal tumor / 中国医师进修杂志

Objective To investigate the therapeutic effect of the hemilaminectomy approach in intraspinal tumor with the help of intraoperative ultrasound,high-speed drill and ultrasound knife.Methods Clinical data of 35 cases with the intraspinal tumor were analyzed retrospectively.All the patients were treated by hemilaminectomy approach,the position of the lesions were fixed by preoperative X-ray and intraoperative ultrasound,root of the spinous process were removed in order to achieve adequate visual field by high-speed drill and ultrasound knife.Electrophysiologic monitoring were used if the lesions were in the spinal cord.Results Total surgical resection was achieved in 32 cases,gross total resection was in 3 cases.Twenty-eight of the 35 cases were followed up.The symptom alteration of the first period ( 1 - 3 months postoperative):improved in 25 cases,no changed in 2 cases,aggravated in 1 case.The symptom alteration of the second period (6-24 months postoperative):no changed in all cases,no stability change of the vertebral column had been found.Conclusions Followed with the development of the electrophysiologic monitoring,high-speed drill,intraoperative ultrasound,the indication of the hemilaminectomy and have no influence of the spinal stability.However,to spinal meningioma which have a wide base,the hemilaminectomy approach may not adapt.

Hemilaminectomy for Removal of Extramedullary or Extradural Spinal Cord Tumors: Medium to Long-Term Clinical Outcomes

PURPOSE: Laminectomy is generally the treatment of choice for removal of spinal tumors. However, it has been shown that laminectomy may cause instability due to damage of posterior elements of the spinal column, which may induce subsequent kyphosis in the future. Therefore, to reduce the risk of deformity and spinal instability after laminectomy, hemilaminectomy has been used. However, the medium to long-term effects of hemilaminectomy on spinal sagittal alignment is not well understood. The present study was performed to evaluate the clinical outcomes, including spinal sagittal alignment of patients, associated with spinal cord tumors treated by surgical excision using hemilaminectomy. MATERIALS AND METHODS: Twenty hemilaminectomy operations at our institute for extramedullary or extradural spinal cord tumors in 19 patients were evaluated retrospectively with an average follow-up of 85 months (range, 40-131 months). Neurological condition was evaluated using the improvement ratio of the Japanese Orthopaedic Association Score (JOA score) for cervical, thoracic myelopathy, or back pain, and sagittal alignment by sagittal Cobb angle of the hemilaminectomied area. RESULTS: The mean improvement ratio of neurological results was 56.7% in the cervical spine (p < 0.01, n = 10), 26.3% in the thoracic spine (not significant, n = 5), and 48.6% in the lumbar spine (NS, n = 5). The sagittal Cobb angle was 4.3 +/- 18.0degrees in the preoperative period and 5.4 +/- 17.6degrees at the latest follow-up, indicating no significant deterioration. CONCLUSION: Hemilaminectomy is useful for extramedullary or extradural spinal cord tumors in providing fair neurological status and restoration of spinal sagittal alignment in medium to long-term follow-up.

Profiles of Spinal Cord Tumors Removed through a Unilateral Hemilaminectomy

OBJECTIVE: To present the profiles of spinal cord tumors that can be removed through a unilateral hemilaminectomy and to demonstrate its usefulness for benign spinal cord tumors that significantly occupy the spinal canal. METHODS: From June 2004 to October 2010, 25 spinal cord tumors were approached with unilateral hemilaminectomy. We calculated the cross-sectional occupying ratio (CSOR) of tumor to spinal canal before and after the operations. RESULTS: The locations of the tumors were intradural extramedullary in 20 cases, extradural in 2, and intramedullary in 3. The levels of the tumors were lumbar in 12, thoracic 9, and cervical 4. In all cases, the tumor was removed grossly and totally without damaging spinal cord or roots. The mean height and width of the lesions we195re 17.64 mm (3-47.5) and 12.62 mm (4-32.7), respectively. The mean CSOR was 69.40% (range, 27.8-96.9%). Postoperative neurological status showed improvement in all patients except one whose neurologic deficit remained unchanged. Postoperative spinal stability was preserved during the follow-up period (mean, 21.5 months) in all cases. Tumor recurrence did not develop during the follow-up period. CONCLUSION: Unilateral hemilaminectomy combined with microsurgical technique provides sufficient space for the removal of diverse spinal cord tumors. The basic profiles of the spinal cord tumors which can be removed through the unilateral hemilaminectomy demonstrate its role for the surgery of the benign spinal cord tumors in various sizes.

Recuperação funcional de cães com doença do disco intervertebral toracolombar submetidos ao tratamento cirúrgico / Functional recovery of dogs with thoracolumbar intervertebral disk disease submitted the surgical treatment

O objetivo deste estudo foi avaliar a recuperação funcional de 33 cães com doença do disco intervertebral (DDIV) toracolombar submetidos ao tratamento cirúrgico, atendidos no Hospital Veterinário Universitário da Universidade Federal de Santa Maria (HVU-UFSM), no período entre 2004 e 2006. Os dados dos animais incluíram raça, idade, sexo, estado neurológico antes da cirurgia, interpretação da radiografia simples e contrastada, duração das deficiências neurológicas até o procedimento cirúrgico, tempo de recuperação pós-cirúrgico, função urinária e fecal e recidiva dos sinais clínicos. Quanto à duração dos sinais neurológicos antes da cirurgia, 27 (81,8 por cento) permaneceram por um período inferior a 15 dias, 20 cães tiveram melhora dos sinais clínicos decorridos 30 dias do procedimento cirúrgico e seis, com mais de 30 dias, sendo que um desses demorou 60 dias para caminhar. Apenas um (3,8 por cento) dos 26 cães que tiveram recuperação funcional satisfatória apresentou incontinência urinária e apenas um (3 por cento) teve recidiva da DDIV. Pode-se concluir que o tratamento cirúrgico promove recuperação funcional satisfatória na maioria dos cães com DDIV toracolombar. O prognóstico para recuperação funcional após o tratamento cirúrgico é tanto melhor quanto menor for o grau de disfunção neurológica e o percentual de recidiva é baixo em animais submetidos a este tipo de terapia.

This report aimed at evaluating the functional recovery of 33 dogs with thoracolumbar intervertebral disk disease (IVDD) admitted at the Veterinary Hospital of Santa Maria Federal University (HVU-UFSM), from 2004 to 2006. The animals underwent surgical treatment. Data obtained from the dogs included: breed, age, sex, neurological status before the surgery, interpretation of the simple x-ray and myelography, duration of clinical signs, days to walking after surgery, urinary and fecal function and disease recurrence. Neurological signs before the surgery kept for a period smaller than 15 days in 27 (81.8 percent) dogs. Twenty dogs presented involution of the neurological signs at 30 days after the surgical procedure, six after 30 days, and one dog elapsed 60 days to return walking. One of the twenty-six dogs that had satisfactory functional recovery had urinary incontinence and two of them presented recurrence of IVDD. This study showed that the surgical treatment promotes satisfactory functional recovery in most of the dogs with thoracolumbar IVD; the prognostic for functional recovery after the surgical treatment is better as smaller the degree of neurological dysfunction and the recurrence percentage is lower when submitted to this therapy type.

Unilateral hemilaminectomy for the microsurgical removal of cervical intraspinal tumors / 中国微创外科杂志

Objective To investigate advantages and disadvantages of unilateral hemilaminectomy for the microsurgical removal of cervical intraspinal tumors. Methods Twenty-three patients with cervical intraspinal tumors were treated microsurgically with unilateral hemilaminectomy. In condition that the vertabral lamina was kept intact in bony structure, an opening (key-hole) was made in the unilateral lamina by using a drill or a small-sized bone rongeur. Then cervical intraspinal tumors were removed via the “key-hole”. Results Tumors were completely removed in all the 23 patients and no symptoms relating nerve injuries were observed. Postoperative follow-up for 3~16 months (mean, 8 months) revealed no recurrence and spinal deformity. Conclusions Unilateral hemilaminectomy for the treatment of cervical intraspinal tumors is a mini-invasive procedure which benefits the spinal stability. The pitfall of the technique lies in limited surgical field.

Clinical Evaluation of Spinal Tuberculosis Treated with Hemilaminectomy

OBJECTIVE: The variable operative methods are underwent as a treatment of tuberculous spondylitis. We propose hemilaminectomy and debridement as a one of operative method at a certain circumstance. METHODS: From July 1998 to June 2002, 13 consecutive patients with spinal tuberculosis were treated surgically in our institution. Among them, the authors analysed 7 patients in whom posterior approach were performed. The lumbar spine was involved in 6 patients, the thoracic in 1. The hemilaminectomy with debridement was done in all cases. The changes in the Kyphotic angle and the height of involved vertebras retrospectively measured from lateral spinal radiographs obtained preoperatively and postoperatively. Mean follow up periods were 16 months. RESULTS: Clinical symptoms and signs were improved in all cases. One patient (14%) was needed anterior fusion because of aggravation of lesion. Another one needed reoperation because of relapse of epidural abscess. The arithmethical average of kyphotic angle was worsened about 2 degrees and that of height loss was lesser than 5% postoperatively. CONCLUSION: The hemilaminectomy with debridement for spinal spondylitis can be a first therapeutic modality in a mild neurologic deficit and minor lesions with extended epidural abscess and granulation tissue to the adjacent vertebras in radiologic finding. Especially if epidural abscess and granulation tissue involve the multiple vertebras, we recommend this operative method.

Surgical Experience of Lumbar Foraminal Disc Herniation by Resecting the Spinous Process and a Part of Hemilamina

Foraminal disc herniation is considered to be a part of extreme lateral disc herniations which have relatively frequent occurrence of about 10% of all lumbar disc herniations. It presents a different clinical feature from that of usual intraspinal disc herniation, in that the prolapsed foraminal disc material compresses the nerve root at the level of disc herniation. Previously many operative procedures for foraminal disc herniations have been introduced with the aids of various diagnostic methods. Intervertebral foraminotomy and total facetectomy are still the most widely used options in treating extreme lateral lumbar disc herniation. But these techniques could result in an unfortunate structural disruption and frequently cause spinal instability and continued postoperative back pain. Recently unilateral partial hemilaminectomy and resection of spinous process followed by discectomy were performed in our hospital. For this procedure, paraspinal muscles were elevated subperiosteally and retracted bilaterally exposing the spinous process and laminae on both sides. After the unilateral partial hemilaminectomy and resection of spinous process preserving articular facet joint, then obliquely downward looking through intervertebral foramen allowed direct visualization of prolapsed foraminal disc and compressed nerve root. Thereafter prolapsed foraminal disc could be successfully removed under direct vision with the preservation of spinal stability. When extraformainal disc coexisted, intertransverse approach was additionally performed.