October 1994, Volume 44, Issue 10

Original Article

Anterolateral Decompression for Traumatic Spinal Cord Compression

Ahmed Ali Shah  ( Department of Neurosurgery, Dow Medical College and Civil Hospital, Karachi. )
Iqbal Ahmed Memon  ( Department of Neurosurgery, Dow Medical College and Civil Hospital, Karachi. )

Abstract

Nine patients with traumatic fractures of doisolumbar spine leading to pain and neurological deficit are presented. All had radiological evidence of spinal cord or quada equina compression, with either monoparesis, paraparesis or sphincter dysfunction alone. All patients underwent anterolateral decom­pression through a transpleural or retroperitoneal approach. Seven patients had bone grafting and spinal stabilization with Webb-Morley system. Two patients had decompression only. The results were favour­able. This approach is safe and effective and allows early mobilization and functional recovery (JPMA44:242,1994).

Introduction

The treatment of spinal injuries has been a most unrewarding and frustrating surgical exercise even in the hands of most experienced surgeons. The classical approach to these problems has been a posterior decompressive laminec­tomy and the surgical literature is full of reports of dismal results1. Alternate methods for dealing with anterior thoracic and lumbar abnormalities have achieved a success rate far exceeding that of standard laminectomy2. Tn 1956, Hodgson and Stock3 developed anterolateral, transthoracic procedure for the treatment of tubereulous spine with excellent results. Anterolateral approach allows a one-stage decompression of the neural tissue and spinal stabilization with metallic prosthe­sis alongwith bone grafting. showed dramatic spinal cord cojnpression from bone and disc material (Figure 3).

Patients and Methods

Nine patients with traumatic fractures of dorsal and lumbar spine were treated at the neurosurgery department of Civil Hospital, Karachi, between 1989 and 1993. There were 8 males and one female (mean age 22 years). Six patients were involved in road traffic accidents and one each had a fall from a tree, an electric pole and one during a grandmal seizure. Five patients had compression fractures involving the body of L1 vertebra, three had D 12 fractures and one had an L2 fracture. Four patients presented with para-paresis, two with mo­noparesis and three had sphincter dysfunction alone. All had pain in addition to their neurological deficit. In two patients with sphincter dysfunction, the injury had taken place more than 6 months previously and the fractures had healed. The other 7 patients presented within 48 hours of injury. Plain radiographs in all patients showed compression fractures involving a single vertebra with retropulsion Angu­lation was seen in 5 patients. One patient had a myelogram which showed a complete block at the level of fractured vertebra (Figure 1).

Three patients had CT-myelogram show­ing compression of ventral subarachnoid space from retropul­sed fragments (Figure 2).

The other five had an MN which All patients had an anterolateral decompression, either through athoracotomy or a retroperitoneal approach, depend­ing on the level of injury, in the lateral decubitus position. A high speed drill was used to resect the relevant pedicle and the bony fragments within the spinal canal. The prolapsed disc was also excised in each case and the dural sac decompressed. Seven patients had a bone graft, taken from the iliac bone or the resected rib, placed in the defect. All the seven had spinal stabilization by the Webb-Morley instrumentation (Figure 4).

There was no mortality and the complications were insignificant and transitory. All patients were ambulatory within 10 days of the surgical procedure and each received physiotherapy for several weeks. Of the four patients with paraparesis, three recovered completely whereas one contin­ues to have unilateral partial foot-drop. All three patients with sphincter dysfunction improved; two completely and one partially. Two patients with monoparesis had a total neurologi­cal recovery. Ourfollow-uphasbeenfrom3 months to 3 years.

Discussion

Spinal injuries are common in Pakistan, not only from the ever increasing road traffic accidents but also from falls from rooftops, trees and electric poles. As there are no spinal wilts, majority of these unfortunate patients with permanent disability suffer tremendously 1mm serious complications such as bedsores, urinary tract infections and chest infections. A small number of patients with partial neurological deficit also face the same bleak future although they have a good potential for recovery, if treated effectively and within reasonable time. The goals of management should there fore be to ensure best possible neurological recovery, provide early mobilization and to prevent delayed spinal instability and pain4. The current management of thoracolumbar spine injuries has changed from the conservative approach of Guttman5 to a more aggressive surgical intervention. It is logical to assume that continued compression of neural tissue canonly hamper neurological recovery and delay mobility4. Surgical decompression and spinal stabilization shortens the period of immobilization, hospitalization and rehabilitation and reduces the degree of spinal deformity and pain4,6. It is generally assumed that for lesions anterior to the cervical spinal cord, an anterior decompression and fusion should be performed, whereas, for posterior lesions, a posterior laminectomy should be done7. This sound reasoning ought to be extended to thoracic and lumbar spine as well, where the compression of neural tissue is anterior, from retmpulsion of bony fragments and disc material. Most surgeons now agree that laminectomy is, at best, inadequate when dealing with ventrally situated lesions2. Anantemlateral decompression through transpleural or retmperitoneal ap­proach allows direct access to the lesion. The neural tissue can be effectively decompressed by removing the offending bone and disc, aniliac orrib graft can be placed for osteogenesis and bony fusion and spinal stabilization afforded by metallic implant application. This would correct the deformity too. We have presented 9 cases treated anterolaterally with favourable results. All these patients had significant neuro­logical deficit and radiological evidence of anterior thecal compression. All of them benefitted from timely surgical intervention and became ambulatory. A one-stage antemlat­end decompression and stabilization through atranspleural or a retroperitoneal approach is a safe and effective method of dealing with thoracic and lumbar spine trauma.

References

1. Perot, P.L. and Munro, D.D. Transthoracic removal of midline thcracic disc protrusions causingspinal cord compression. J. Neurosurg., 1969;31:452-58.
2. Lobosky, J.M., Hitchon, RW. and McDennell, D.E. Transthoracic anterolateral decompres­sion foe thoracic spine lesions. Neurosurgery, 1984;14:26-30.
3. Hodgson, AR. and Stock, FE. Anterior spinal fusion. A preliminary communication on the radical treatment of Pott\\\'s disease and Pott\\\'s paraplegia. Br. J. Surg., 1957;44:266-75.
4. Bose, B., Osterholm, J.L., Northnup, B.E. et al. Management of lumbar translocation injuries Case reports. Neurosurgery, 1985;1 7:958-61.
5. Guttman, L. Spinal deformities in traumatic paraplegics and tetraplegics following surgical procedures. Paraplegia, 1969;7:38-58.
6. Jacobs, R.R., Ather, M.A. and Srider, R.K., Thoracolumbar spinal injuries. A comparative study ofrecumbent and operative Irealmentin 100 patients. Spine, 1980;5:463.77.
7. Benzel, E.C., and Larson, S. J. Functional recovery after decompressive operation for thorseic and lumber spine fractures. Neurosurgesy, 1986;19:772-78.

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