A

Fig. 3.42. (Continued) The postoperative sagittal (g) and axial (h) T1-weighted, contrast-enhanced MRI scans reveal a complete resection, but also an extensive posterior fixation of the cord to the dura. The excellent postoperative neurological outcome lasted for 1 year. Since then the has patient suffered from a severe dysesthesia syndrome and myelopathy. Within 8 years, no tumor recurrence has developed Fig. 3.42. (Continued) The postoperative sagittal (g) and axial (h) T1-weighted,...

Acknowledgments

We would like to thank all of our colleagues listed below, who were trained by the senior author and have contributed to the surgical treatment of the patients of this series S. Al Zaher, L.M. Auer, H. Baumann, M. Bellinzona, M. Berger, H.W. Bothe, D.K. B ker, G. Carvalho, G. Chhadeh, R. Eghbal, M. El Azm, T. G nther, B. Hermans, K.D. Lerch, T. Lutz, C. Matthies, F. Meyer, S. Mirzai, J.R. Moringlane, G. Mtafu, M. Nakamura, G. Penkert, A. Piepgras, W. Pr samer, R. Ramina, S. Rosahl, R. Sch...

Angioblastomas

Angioblastomas represent about 2.1 145, 247 to 5 276 of spinal tumors according to the literature, and about 1.9 of all spinal and 11.8 of intramedullary tumors in our series. They tend to occupy the posterior, paramedian aspect of the spinal cord (Figs. 3.34 and 3.48) 185, 198, 223, 336 . However, centrally or anteriorly located angioblastomas do occur (Fig. 3.49) 134, 264 . We have operated on 21 intramedullary angioblas-tomas affecting nine female and eight male patients (Table 3.26). Ten...

Clinical Results

The immediate postoperative result is related to the preoperative status, the spinal level of the tumor, and the experience of the surgeon regardless of tumor histology 6, 38, 54, 60, 80, 82, 84, 85, 94, 95, 115, 118, 124, 204, 252, 271, 301, 317, 335, 346, 347 . The extent of tumor removal has only a minor influence on the short-term postoperative outcome 6, 56, 118, 215 . *p< 0.05, **p< 0.01 statistically significant difference between preoperative status and 1 year or 6 months...

Conclusions

We conclude that intramedullary tumors should be operated on as soon as neurological symptoms have appeared. Waiting for further neurological progression raises the risk of surgery dramatically If a syrinx accompanies the tumor, this should be interpreted as a favorable prognostic sign as it indicates a displacing rather than infiltrating tumor, and thus suggests its resectability. It is sufficient to operate on the solid tumor part. The accompanying syrinx will decrease automatically if the...

Diagnostic Imaging

The first endeavors on spinal cord surgery were performed without any imaging of the lesions. Radiological signs of a spinal tumor, such as a widening of the spinal canal or erosion of bony elements, were rarely encountered 7, 30, 39,40,45 . Neurologists determined the spinal level of the suspected tumor clinically and the surgeon had to do the operation to confirm the diagnosis and to remove the tumor. The major differential diagnostic sign was an increased intensity of neurological deficits...

Foreword

The request from Professor J rg Klekamp for me to write the foreword for this monograph was an appealing challenge. Prior to the era of microneuro-surgery, I was firmly involved in the surgery of spinal lesions, and achieved surgical removal of spinal arteriovenous malformations (AVMs) on 12 patients in the years between 1960 and 1965. Microneurosurgical techniques were introduced in Zurich in 1962, and since then I have applied these techniques to the exploration of the various spinal lesions...

History

1.1 Surgical Approaches 1 1.2 Tumor Removal 2 1.3 Diagnostic Imaging 3 1.4 Spinal Reconstruction and Fusion 3 1.5 Modern Advances 4 2.1 Cervical Spine 7 2.2 Thoracic Spine 10 2.3 Lumbar Spine and Sacrum 12 2.4 Spinal Biomechanics 14 2.5 Spinal Meninges 14 2.6 Spinal Cord and Nerve Roots 15 3.1 History and Diagnosis 20 21 40 41 3.3.2 Tumor Removal 42 82 3.3.4 Adjuvant Therapy 82 3.4 Postoperative Results and Outcome 84 3.4.1 Tumor Resection 84 3.4.2 Clinical 3.4.5 Morbidity, Recurrences, and...

I

Spinal cord on the Tl-weighted image. Only the T2-weighted image demonstrates a demarcation toward the cord with a slightly hyperdense rim Fig. 3.15. Sagittal T1-weighted MRI without (a) and with contrast enhancement (b), of a cystic WHO grade I astrocytoma at C2-C4 in a 22-year-old woman. Just the solid part Fig. 3.15. Sagittal T1-weighted MRI without (a) and with contrast enhancement (b), of a cystic WHO grade I astrocytoma at C2-C4 in a 22-year-old woman. Just the solid part at C3 4 takes up...

Info

Abbreviation Fenestr. fenestration Fig. 3.84. (Continued) g A GoreTex duraplasty was inserted. h The postoperative T1-weighted MRI demonstrates a good decompression of the cervical cord andafree CSF passage in the operated area. Preoperative symptoms improved Abbreviation Fenestr. fenestration nent clinical problem 99 , with four patients developing motor deficits. According to our experience with syringomyelia, we have been reluctant to place shunts in these cysts. Only one patient underwent...

J

Survival rates for patients with intramedullary astrocytomas as a function of age (log-rank test p 0.074) Fig. 3.76. Survival rates for patients with intramedullary astrocytomas as a function of age (log-rank test p 0.074) Table 3.25. Multivariate analysis for prediction of high survival rate for intramedullary astrocytomas Overall, this analysis shows that pediatric and adult patients demonstrate different biological behaviors of these tumors. In children, the postoperative course...

Lumbar Spine and Sacrum

Similarly to the thoracic vertebrae, the five lumbar vertebral bodies are rectangular in shape, with flat superior and inferior surfaces. The pedicles project posterolaterally. The neural foraminae exit almost laterally. The posterior border of each foramen is formed by the articular processes. These processes are comparably long and form the facet joints, which are oriented in the coronal plane. The lumbar laminae form an oval spinal canal in the upper lumbar spine. In the lower part, the...

Melanocytomas

Intramedullary melanocytomas are extremely rare. They have to be differentiated from melanomas and melanoma metastases. Glick et al. 106 published a series of seven patients. They performed detailed pathological examinations and concluded that mela-nocytomas lack anaplastic features but demonstrate local aggressive behavior. On the other hand, two case reports of patients with melanocytomas have been published with rather rapid neurological progression and death. Barth et al. 16 reported on a...

Of Spinal Tumors

Christliches Krankenhaus Quackenbr ck International Neuroscience Institute (INI) Rudolf-Pichlmayr-Stra e 4 30625 Hannover Germany ISBN 978-3-540-44714-6 Springer Berlin Heidelberg New York Library of Congress Control Number 2006940545 This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilm or in any other way,...

References

Cloyd MW, Low FN (1974) Scanning electron microscopy of the subarachnoid space in the dog. I. Spinal cord levels. J Comp Neurol 153 325-368 2. Djindjian R (1984) Vascular malformations. In Shapiro R (ed) Myelography, 4th edn. Year Book Medical Publishers, Chicago, pp 318-344 3. Dubois PJ, Drayer BP, Sage M, Osborne D, Heinz ER (1981) Intramedullary penetrance of metrizamide in the dog spinal cord. AJNR 2 313-317 4. Harms J, Tabasso G (1999) Instrumented Spinal Surgery. Principles and Technique....

Spinal Biomechanics

The line of the center of gravity of the erect human body lies anterior to the vertebral column. As a consequence, axial loads to the body in the upright position result in a combination of spinal axial compression and bending movements. A simple biomechanical concept of the spine is as two columns, an anterior column and a posterior column 6 . The anterior column provides the weight-bearing part of the spine. About 80 of the axial load is absorbed by this column, whereas the remaining 20 is...

Spinal Meninges

The dura mater is about 0.8 mm thick and consists of collagen and elastic fibers. At the foramen magnum, the dura mater of the head and the external periost merge into the spinal dura mater. Here, the dura mater consists of three layers (1) the innermost layer of the spinal dura is in continuity with the inner dural layer of the skull, (2) the middle spinal layer continues to form the external dural layer of the skull, and (3) the outer layer transgresses into the periost of the skull (Fig....

Spinal Reconstruction and Fusion

With the introduction of approaches to the spine and increasing surgical attempts to treat spinal tumors as well as spinal trauma and degenerative disorders, little concern existed for spinal stability among neurosurgeons - not to mention for the side effects of surgery on spinal stability. First attempts to reconstruct the vertebral column were met with great scepticism by many respected neurosurgeons because reconstruction and stabilization meant longer surgery, a risk of insufficient...

Thoracic Spine

The 12 thoracic vertebral bodies are rectangularly shaped with flat superior and inferior surfaces. The neural foraminae exit almost laterally. From top to bottom, the height of the bodies gradually increases. The intervertebral discs appear flatter than their cervical and lumbar counterparts. The pedicles of the thoracic vertebrae extend from the superior half of the vertebral body. The neuroforaminae are directed laterally The laminae form an almost circular spinal canal of constant width...

Tumor Removal

So, with the technique of laminectomy, the standard approach to spinal lesions was available in the second half of the 19th century. The first spinal tumor operation is widely attributed to Victor Horsley, who described the removal of a spinal meningioma, performed on June 9th in 1887 20 . However, Lecat operated on a spinal tumor as early as 1753 32 . Mace-wen reported on two patients in whom he had removed fibrous neoplasms of the dura in 1883 and 1884, respectively 33, 34 . As he was not a...

Preface

Spinal tumors are rare and potentially devastating lesions that threaten the patient's mobility or even life. Despite their rarity, every neurosurgeon in clinical practice has to deal with them regularly. With modern imaging, microsurgical techniques, and improved understanding of spinal biomechanics and modern instrumentation systems, the fate of complete paraplegia can be avoided if therapy is instituted in time. Whereas intramedullary and extra-medullary tumors are the domain of the...

Surgery

Before describing the surgical techniques and strategies for removal of intramedullary tumors, we would like to comment on the perioperative use of cortico-steroids. Several colleagues give high-dose corticoste-roids before, during, and 24 h after surgery for an intramedullary tumor 130, 263 . In 1990 the results of the Second National Acute Spinal Cord Injury Study (NASCIS II) were published, which showed that the administration of a high-dose regimen of methyl- prednisolone could improve...

Ependymomas

Ependymomas and astrocytomas are the most frequent intramedullary tumors. Ependymomas of the spinal canal may be located intramedullarly, attached to the filum terminale, or even extradurally originating from heterotopic ependyma cells 226, 230 . Unlike some authors, we have eliminated ependymomas of the filum terminale from the analysis of intramedullary ependymomas. They are discussed in the section on extramedullary tumors. Intramedullary ependymomas are solitary tumors that are located...

Modern Advances

With good anesthetic techniques, antibiotic treatment, and reasonable diagnostic imaging established, the next major advance was the introduction of the operative microscope in the 1960s. Before the introduction of microsurgery, surgeons were most of all concerned for the patients' survival after spinal cord surgery. With the advent of the operative microscope, it became possible to preserve the patients' neurological function with increasing frequency. In 1975, Yas-argil and De Preux published...

Metastases

Intramedullary metastases are rare complications of cancerous diseases. In the literature, case reports predominate for this topic. In a recent review, Kalayci et al. 159 evaluated 284 patients reported in the English literature. Of these, just 32 had been treated surgically. Prior to MRI, such lesions were usually diagnosed at autopsy 53, 110 . Miller and McCutcheon 223 gave a figure of 24 for cerebral metastases among autopsied cancer patients, compared to 0.014 with intramedullary...

Gangliogliomas

Gangliogliomas are rare intramedullary tumors. We have encountered two such patients one 4-year-old boy showed a tumor at Th2-T5 that was resected sub-totally, while the cervical tumor at C5 6 in a 27-year-old woman could be removed completely (Fig. 3.89) with excellent outcomes in both patients. Gangliogliomas have been reported in pediatric series of intramedullary tumors, while adult patients are usually affected at a comparably young age 131, 153, 250, 253, 340 . Constantini et al. 54 found...

Epidural Tumors

5.1 History and Diagnosis 322 5.2.1 Soft-Tissue Tumors 324 5.2.2 Bone Tumors 335 5.3.1 Soft-Tissue Tumors 361 5.3.2 Bone Tumors 367 5.3.3 Reconstruction, Stabilization, and Closure . . . 392 5.3.4 Adjuvant Therapy 396 5.4 Postoperative Results and Outcome 400 5.4.1 Tumor Resection and Spinal Instrumentation 400 5.4.2 Clinical Results 401 5.4.4 Morbidity, Recurrences, and Survival 407 5.5 Specific Entities 412 5.5.1 Soft-tissue Tumors 5.5.2 Bone Tumors 450 References Subject Index 523

History and Diagnosis

In our series, about one-third of patients experienced some form of pain as their first symptom. The remainder complained about sensory deficits, paresthe-sias, motor weakness, or gait problems as their first manifestation in about equal proportions. With malignant tumors, almost all patient complained about pain, gait ataxia, or motor weakness right form the start (Table 3.2). In general, the case history averaged about 33 44 months, with considerable variability, ranging between 1 week and 28...

Schwannomas

Intramedullary schwannomas resemble an even rarer entity. In the literature, a number of case reports have been published 33, 95, 138, 150, 191, 209, 220, 240, 248, 249 . These tumors have grown into the spinal cord originating from a nerve root right at the entry zone. We have seen one such tumor in a 28-year-old woman with a 6-year history of slightly progressive gait ataxia. She demonstrated a contrast-enhancing tumor above the conus at Th11. At surgery, more than half of this tumor was...

Dermoid Cysts

With dermoid cysts the situation is different they contain cells that produce some kind of gradually accumulating product. This will increase the size of the cyst with the potential of progressive pressure on the spinal cord. The history is considerably shorter compared to lipomas - 29 51 months in this series, ranging from 1 month to 10 years. Even acute presentations related to aseptic meningitis 65, 296 or abscess formation 49 have been described. The average age was 32 6 years (range 25-42...

Cervical Spine

Occipital Condyle Mri

The cervical spine consists of two special vertebrae - the atlas and axis - connecting the spine with the cranium in a complex set of joints and ligaments, and five ordinary vertebrae in a slightly lordotic curve (Figs. 2.1-2.3). In young adults, the average length of the cervical spine measures 12.5 cm from the lower border of C7 to the tip of the dens axis. In retroflexion, the average length is 11.5 cm, compared to 12.69 cm in anteflexion 9, 10 . This needs to be considered for correct...

Removal of Recurrent Tumors

For reoperation of an intramedullary tumor, the removal of the epidural scar may cause some problems. As a general principle, the dissection of the dura should start in an area not involved with the previous operation, preferably at the upper and lower margins of the first operation. With a small part of the neighboring lamina removed, the dura is identified and further dissection can be done much easier. If the first laminectomy has been extended further laterally than required, we just expose...

Short Term Complications

Complications were encountered in 15 of patients (Table 3.9). The commonest problem was a postoperative CSF fistula. This complication is avoidable with a meticulous dura suture and tight soft-tissue closure, especially of the muscular layer. In recurrent cases, soft-tissue scarring puts the patient at an increased risk for fistula formation. In such instances we recommend insertion of a lumbar drain at surgery and to keep it for about 1 week as a preventive measure, especially if a Gore-Tex...

Closure

Once the tumor is removed we check that hemostasis is adequate. Inside the tumor bed we use as little coagulation as possible and recommend small cotton paddies, irrigation, and simply taking some time. To avoid adhesions between the tumor bed and the dura, we use a few 8-0 sutures to close the pia of the cord provided thetumor mass couldberemoved(Figs. 3.33, 3.36-3.38, 3.47, 3.52, and 3.53) 204 . Although recommended by some authors to prevent arachnoid scarring, we do not close the arachnoid...

Glioependymal Cysts

Mri Scan L1l2

Intramedullary glioependymal cysts are observed predominantly in the area of the conus medullaris (Figs. 3.82 and 3.83), but may occur anywhere in the spinal canal (Fig. 3.84) 279 . The cyst contains fluid that is similar to CSF 279 . Some authors have called these cysts terminal ventricles or considered them to be an isolated eccentric syrinx of the conus medul-laris. The majority of them are observed in adults, with most pediatric cases being asymptomatic 50 . The differential diagnosis to...

Neuroradiology

Without any doubt, MRI has revolutionized our pre-operative possibilities to establish the diagnosis, determine the exact extent of the tumor (Figs. 3.1 and 3.2), and visualize associated cysts (Figs. 3.1 and 3.2) 37, 282, 357 . Nobody will operate on an intramedul-lary tumor anymore without an adequate preopera-tive MRI scan. Except for patients unable to undergo an MRI, computed tomography (CT) with contrast or myelography is no longer required 161, 165, 247 . Fig. 3.2. These sagittal T2- (a)...

Removal of Astrocytomas

In general, astrocytomas have to be considered as infiltrating tumors. Therefore, the identification of cleavage planes carries considerable risks and may even be outright impossible 130,204 . However, some astrocytomas do present cleavage planes, allowing a complete resection using similar dissection techniques as described for ependymomas. The strategy of choice is to remove them from inside out 80 . In tumors with ill-defined margins, CUSA is ideal to de-bulk the mass. Astrocytomas may...

Removal of Hamartomas

Intramedullary dermoid cysts are growing lesions due to the metabolic activity of the cells in the cyst wall. These do not proliferate, but continue to produce substances that fill the cyst causing its expansion. Thus, radical excision of the entire cyst and its wall is the goal of surgery. Otherwise, a recurrence is almost certain. Unfortunately, this may be extremely difficult to achieve. The cyst wall may be extremely adherent to the spinal cord tissue requiring sharp dissection to deliver...

Long Term Complications

Late complications may be associated with spinal instability or postsurgical myelopathy. To avoid instabilities, intervertebral joints should be left intact during the exposure. It is not necessary to extend the exposure so wide that these joints are compromised. However, postoperative instabilities cannot be prevented by a small laminotomy alone. This complication becomes more common the higher the spinal level and the younger the patient is 131, 234 , even though Yeh et al. 352 found a...

Removal of Angioblastomas

Cholesterol Granuloma Petrous Apex

As a considerable number of intramedullary angioblastomas are associated with a syrinx, the precise localization of the solid tumor part is of particular importance. In most instances, arterialized and dilated veins cover the posterior surface of the cord at and next to the angioblastoma. In some instances, the characteristic orange color of the lesion is apparent right underneath the pia mater (Figs. 3.34, 3.38, and 3.48). In all other cases, ultrasound is a valuable tool to determine the...

Removal of Ependymomas

In general, ependymomas are completely resectable 204,301 . They displace rather than infiltrate the spinal cord. Some ependymomas may exert such enormous pressure that they almost come out by themselves once the pia has been opened (Fig. 3.40) 217 . In such instances, the pia has to be opened quickly over the entire extension of the tumor and blunt in struments should be used for posterior and lateral dissection of the tumor. With an insufficient pial opening, on the other hand, posterior...

Removal of Cavernomas

With cavernomas, coagulation of the lesion will shrink it to such a degree that feeding vessels become identifiable, which then can be closed and transected. The hemosiderin-stained glial tissue around a caver-noma should not be removed. It is the result of repeated minor hemorrhages, does not belong to the pathology, and helps to preserve the surrounding cord tissue as a good protective layer (Fig. 3.52) 34, 216, 246 . Furthermore, some cavernomas are accompanied by large veins, so called...

Cavernomas

Intramedullary cavernomas are rare pathologies and represented 3 of our intramedullary pathologies 69 . On even rarer occasions they may be associated with familial multiple cavernomas of the central nervous system (Fig. 3.85) 69,187 . Despite being so rare, this entity has attracted a considerable number of publications 1, 32, 34, 61, 69, 70, 109, 216, 219, 244, 246, 293, 308, 315, 337, 354 . The majority of patients are women 32, 61, 244 . The preoperative clinical course tends to be...

White Spot In Spinal Cord

Intramedullary Spinal Cord Tumors

Tl-weighted, contrast-enhanced, sagittal a and axial b MRI scans of a cavernoma at Th4 in a 57-year-old patient. The patchy contrast enhancement and irregular shape of the tumor as well as the black hemosiderin remnants on T2 c are typical for this tumor Fig. 3.18. Tl-weighted sagittal a and axial i MRI scans of an ependymal cyst of the conus in a 45-year-old woman. The cyst is located anteriorly on the left side. Please note the considerable space-occupying effect of this cyst Fig....