:Acta Ncuro&irurgica

Acta Neurochir (Wien)(1992): 116: 176-178

9 Springer-Verlag [992 Printed in Austria

Surgery of Intramedullary Spinal Cord Tumours* J. Brotchi 1, J. Noterman 1, and D. Baleriaux 2 Departments of Neurosurgery1 and Neuroradiology2, Erasme Hospital, Universityof Brussels, Belgium

Summary MRI and Cusa have significantly modified the diagnosis and the treatment of intramedullary tumours. Our experience, based on 66 cases, is in favour of surgery performed when the patient's neurological status is still good. Radical surgery, whenever possible, is the best treatment and can be achieved for many histological diagnoses, even in gliomas where we succeeded in 36% of the cases. Surgery is the only way to be sure of the exact histological diagnosis of the lesion which can be suggested in 70% of the cases but not confirmed by MRI.

Keywords: Intramedullary tumour; diagnosis; management; results.

Introduction Magnetic Resonance Imaging (MRI) has significantly modified the diagnosis of intraspinal cord tumours. Intramedullary tumours are well defined, the cystic and the solid parts of the tumour are well demonstrated with this method of investigation. This allows a safer surgical approach and a more aggressive treatment as described by several authors 3' 4, 5, 11, 13 Since 1984, we have operated on 66 cases, all of them studied by MRI as reported previously 1' 2, 3

Material and Methods All patients were investigated with MRI: T1 and T2-weighted images in the 3 planes were obtained in all cases. Gadolinium has been widelyused since 1988. Pathological findings were: low grade astrocytomas (22 cases), ependymomas(17 cases), haemangioblastomas (9 cases), metastases (6 cases), epidermoidcysts (2 cases), sarcoidosis(2 cases), cavernoma (I case), lipomas (5 cases), and astrogliosis (2 cases).

Surgical Technique According to pre-operative MRI evaluation, a limited laminectomy (laminotomy in children) is per* Invited Lecture, presentedat the European Congress of Neurosurgery, Moscow, June 23-29, 1991.

formed over the solid part of the tumour only. Except in lipoma where a decompressive procedure with a moderate reduction of the mass was done and in haemangioblastomas which were dissected from the normal spinal cord, a myelotomy in the midline was performed in all the cases when the tumour was not superficial. We use pial traction sutures to maintain the spinal cord open. Myelotomy is done all over the solid part of the tumour. We search for the poles and we open there the frequently associated cystic cavities. We like to use the Cavitron Ultrasonic Surgical Aspirator (CUSA, Cooper Medical Devices, Stanford, Connecticut) for debulking the tumour, especially astrocytomas and ependymomas. As most of the time, the only landmark between the tumour and the normal spinal cord is the difference of colour, we are not impressed with the use of CO2-1aser which chars the tissue. With the Cusa, we gently reduce the volume of the tumour, working inside the lesion, avoiding manipulation of the spinal cord. We like to use cotton pledgets to dissect the tumoural walls from the normal spinal cord. Sometimes, the tumour is very infiltrative. In that case, it is better to stop the procedure without forgetting to do a biopsy. Recently, we decided to close the spinal cord opening with separate non-watertight microsutures. A closure of the arachnoid layer was also performed whenever possible, with the aim to restore the normal layers and to avoid post-operative pain.

Results MRI gave the correct diagnosis in all lipomas, haemangioblastomas and epidermoid tumours. The differential diagnosis between astrocytoma and ependymoma is not always easy just as is the case with the diagnosis of metastasis when a primary cancer is unknown. In our series, the pre-operative histological di-

J. Brotchi et al.: Surgery of Intramedullary Spinal Cord Tumours

agnosis predicted by M R I was correct in approximately 70% of the cases. Surgical results varied according to the location of the tumour, the nature of the tumour and the procedure performed. In our hands, the most difficult location was at the conus medullaris where we were unable to do more than a single biopsy in astrocytomas. On the contrary, the cervico-medullary junction was not an obstacle to total resection. Astrocytomas were the most difficult lesions to cure. In 36% of our cases (8 of 22), we found a plane of cleavage between the tumour and the spinal cord and we were able to resect tumour even at the cervico-medullary junction. Two patients had been previously treated in other centers, after biopsy by radiotherapy. Surgery was very difficult, the midline unclear and arachnoiditis a problem. Both patients are worse and have severe postoperative deficits. Metastases were difficult to operate upon because of the peritumoural oedema which is not an advantage in the spinal cord contrary to the brain. Twelve of 17 ependymomas were totally removed. In 5 cases, resection was partial either because the lesion was located in the conus or because a marked infiltration of the turnout. We had no postoperative death. All the patients were evaluated 3 months after surgery to assess their neurological status. We observed 6 cases were worse postoperatively, 25 stable and 35 cases were improved. The results were independent of the type of surgery: 9% worse, 54% stable, and 37% improved after biopsy and decompressive surgery. Partial resection resulted in worsening (13%), less stable (36%) and more improvement (51%). Gross total resection was accompanied by 6% worsening, 33% stable, and 61% improvement. So far, we have had no recurrence after gross total removal even in gliomas but our follow-up is too short (7 years in our oldest cases) to draw any conclusion. Discussion

With the exception of lipomas, haemangioblastomas, dermoid and epidermoid tumours which have characteristic signals 12' 13 M R I is unable to predict the histological composition of a tumour with certainty. Many ependymomas resemble astrocytomas 12. In our series, 12 turnouts, referred to us with a diagnosis of "diffuse inoperable glioma", were in reality 11 ependymomas and 1 glioma. All were cured. This assertion was based on incomplete M R I studies, without gadolinium scans. The possibility of surgical treatment

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was reconsidered after a completely new M R I examination. Our two cases of sarcoidosis were surgical discoveries. They were operated on with a diagnosis of glioma as reported elsewhere 9' 10. Surgery revealed a diffuse lesion. A biopsy was taken and no attempt at removal was made. Both cases were treated with corticosteroids post-operatively. One showed complete recovery, the second case remained unchanged. Without surgery, the diagnosis of sarcoidosis would never have been made, emphasizing the importance of histology. Cusa allows a gentle debulking of the tumour without displacement of neural tissue. We are not convinced of the usefulness of the CO2-1aser in this type of surgery even if others have reported good results 5'6' 14. We think that the only landmark between the tumour and the normal spinal cord, normally the colour, is lost due to tissue charring. Since the development of MRI, we do not use intra-operative ultrasound imaging which is useful to locate the cysts and the solid part of the tumour 7. Nowadays, M R I gives such a nice picture that we need no further details except in very small lesions difficult to find. The surgical results are in favour of an aggressive strategy whenever possible. After gross total resection (33 cases out of 66 tumours: 50%) the neurological status recorded 3 months after surgery is not in favour of partial resection nor biopsy. As shown by Cooper and Epstein 5, the quality of life depends on the preoperative neurological status. No paraplegic patients recovered in our series. On the other hand, we have documented 24 patients whose condition stabilized (36%). That means that intramedullary turnouts must be operated on while the patient can still walk. There is no benefit in stabilizing somebody in a wheel chair. Finally, there is no place for radiotherapy without histological diagnosis nor any indication for its use in treating intramedullary tumours except in high-grade gliomas which are very rare 3. In cases of late recurrence, we would recommand operating again. References 1. Brotchi J (1987) Les tumeurs intram~dullaires/t l'6poque de la r6sonance magn6tique et du Cusa. Sem Hop (Paris) 63: 34033405 2. Brotchi J (1989) Tumeurs intram6dullaires. In: Cohadon F (ed) Tumeurs du syst6me nerveux et de ses enveloppes. Flammarion, Paris, pp 649-653 3. Brotchi J, Dewitte O, Levivier M, Baleriaux D, Vandesteene A, Raftopoulos C, Flament-Durand J, Noterman J (199 I) A survey

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J. Brotchi etal.: Surgery of Intramedullary Spinal Cord Tumours of 65 tumours within the spinal cord: Surgical results and the importance of pre-operative magnetic resonance imaging. Neurosurgery 29:651-657 Cooper PR (1989) Outcome after operative treatment of intramedullary spinal cord tumour in adults: Intermediate and longterm results in 51 patients. Neurosurgery 25:855-859 Cooper PR, Epstein F (i 985) Radical resection ofintramedullary spinal cord tumours in adults. J Neurosurg 63:492-499 Epstein F, Epstein N (1982) Surgical spinal cord astrocytomas of childhood. A series of 19 patients. J Neurosurg 57:685-689 Epstein FJ, Farmer JP, Schneider SJ (199!) Intra operative ultrasonography: An important surgical adjuvant for intramedullary tumours. J Neurosurg 74:729-733 Epstein F, Wisoff J (1987) Intra-axial tumours of the cervicomedullary junction. J Neurosurg 67:483-487 Levivier M, Brotchi J, Baleriaux D, Pirotte B, Flament-Durand J (1991) Sarcoidosis presenting as an isolated intramedullary tumour. Neurosurgery 29:271-276 Levivier M, Baleriaux D, Matos C, Pirotte B, Brotchi J (1991) Sarcoid myelopathy. Neurology 41:1539-1540

11. McCormick PC, Torres R, Post KD, Stein BM (1990) Intramedullary ependymoma of the spinal cord. J Neurosurg 72: 523532 12. Parizel PM, Baleriaux D, Rodesch G, Segebarth C, Lalmand B, Christophe C, Lemort M, Haesendonck P, Niendorf HP, Flament-Durand J, Brotchi J (1989) Gd-DTPA-enhanced MR-imaging of spinal tumours. AJNR 10:249-258 13. Penisson-Besnier I, Guy G, Gandon Y (1989) Intramedullary epidermoid cyst evaluated by computed tomographic scan and magnetic resonance imaging: case report. Neurosurgery 25: 955959 14. Roux FX, Rey A, Lecoz P, George B, Thuret C, Cophignon J, Mikol J (1984) Astrocytomes et 6pendymomes intram6dullaires de l'adulte. La tactique th6rapeutique infiue-t-elle sur les r6sultats ~i long terme? Bilan de 23 cas op6r6s et discussion de la litt~rature. Neurochirurgie 30:99-105 Correspondence and Reprints: Prof. Jacques Brotchi, M.D., Department of Neurosurgery, Erasme Hospital, 808, route de Lennik, B-1070 Brussels, Belgium.

Surgery of intramedullary spinal cord tumours.

MRI and Cusa have significantly modified the diagnosis and the treatment of intramedullary tumours. Our experience, based on 66 cases, is in favour of...
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