Eur Spine J DOI 10.1007/s00586-013-3153-2
CASE REPORT
Lateral mass lesions of the C1 vertebra: a modified ‘‘far lateral’’ approach Michael Winking
Received: 7 May 2013 / Revised: 22 December 2013 / Accepted: 22 December 2013 Ó Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose The surgical removal of lateral mass lesions is demanding due to their close anatomical relationship with the vertebral artery, upper spinal cord as well as overlying muscular structures. Usually a dorsal approach will be performed to reach the lateral mass. The disadvantage of this approach is the extensive mobilization of the neck muscles required to allow exposure of the lateral mass, which can be accompanied by severe muscular atrophy due to the damage of the local innervation. Additionally, management of the exposure of the vertebral artery is hindered by the dorsal approach. Methods A modified ‘‘far lateral’’ approach with complete resection of the lateral mass of C1 followed by a substitute with a Harms cage is presented. Results A 54-year-old woman was suffering from severe neck pain accompanied by a progressive sliding of her head and the visual axis to the right hand side. MRI as well as CT scans showed an osteolytic destruction of the right lateral mass of C1. After occipito-cervical fusion the osteolytic lateral mass was removed using a far lateral approach to the upper cervical spine. The patient recovered immediately after surgery, the neck pain improved and the lateral bending of the head was balanced. Conclusions This far lateral approach offers the advantage of direct visualization of the lateral aspect of the upper cervical spine with the opportunity for local stabilization at the center of rotation. Keywords Lateral mass C1 Osteolytic destruction Far lateral approach M. Winking (&) ZW-O Spine Center Osnabrueck, Am Finkenhuegel 3, 49076 Osnabrueck, Germany e-mail: [email protected]
Introduction Laterally placed lesions in the upper cervical spine present technical problems for removal. A ventral approach is adequate for pathologies localized in the vertebral bodies, the discs or the spinal cord. In the C1–C2 region those approaches have to be done transorally [2]. Resection of the lateral mass of C1 including preparation of the vertebral artery is very limited using this approach. Using a retropharyngeal approach you can reach the lateral mass passing the submandibular gland, cutting parts of the digastric muscle and mobilizing the hypoglossal nerve. This approach is demanding because there are several anatomical structures at risk [5]. A dorsal approach has advantages in that it allows exposure of the dorsal aspect of the spinal canal or the dorso-lateral region of the vertebra [7, 8]. For pathologies of the lateral mass this technique is also limited. The vertebral artery leaves the vertebral canal far laterally with a loop before entering the foramen magnum. This will be identified at the end of the preparation from the dorsal side. Significant traction on the paravertebral muscles is necessary to expose the transverse process of C1. This is associated with the risk of damage to local innervation of the paravertebral muscles. Already in 1917 a lateral approach to the upper cervical spine was described for treatment of vertebral artery aneurysms [4]. This approach was adapted for surgery in the ventral portion of the spinal canal from the foramen magnum to the superior portion of C3 [6]. Using this approach an incision is made at the anterior border of the sternocleidomastoid muscle. After identification of the tip of the transverse process of C1 and muscle detachment, the C1 lamina is resected for intraspinal tumor removal [1]. This approach is orientated to the ventral part of the spinal canal. In this paper we describe a modification, which is able to expose the whole C1 vertebra from the lateral side.
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Eur Spine J Fig. 1 Preoperative axial CT and MRI scan showing the osteolytic destruction of the C1 vertebral body. The white arrows indicate the tumor mass
Fig. 3 The skin incision marked from the right suboccipital region to the ventral side of the sternocleidomastoid muscle. Right earlap is fixed by sutures head is fixed by Mayfield clamp with a slight flexion to the left side Fig. 2 Preoperative 3D reconstruction of the upper cervical spine. Arrows indicate the destruction of the right lateral mass of C1
Case report History We present the case of a 54-year-old woman complaining of neck pain in the upper cervical region accompanied by progressive lateral bending of her head. Pain was intensified by rotation of the head as well as by flexion and extension. There was no radicular pain, no palsy, but a slight hypesthesia in the forearm on the right hand side. Comorbidities included chronic pancreatitis and ulcerative colitis but no history of tumor. Complete laboratory examination, including tumor markers as well gammopathy diagnostics, was without abnormalities. A bone marrow biopsy was assessed as unremarkable.
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Imaging MR and CT imaging studies showed an osteolytic destruction of the right lateral mass not crossing the midline of C1 but destroying the cortical bone (Figs. 1a, b, 2). The perfusion of both vertebral arteries was assessed using angiography. Additional occlusion testing of the right vertebral artery was tolerated without permanent or transient neurological symptoms. A full body CT for tumor staging revealed no further malignancies. Surgical technique Because the lesion was destroying the lateral mass, a resection combined with stabilization was planned. During the first step an occipito-cervical fusion was performed using a dorsal screw rod system with an occipital plate. Because of the destruction of the lateral mass with the loss
Eur Spine J
Fig. 4 Intraoperative view after removal of the lateral mass of C1
of axial loading capacity, a local cage stabilization between C0 and C2 was planned for the second step (Fig. 2). For this purpose, a modified far lateral approach was chosen. The patient was positioned in a left lateral position with the head slightly flexed downwards. A hockey stickshaped skin incision was performed starting at the mastoid and running on the ventral side of the sternocleidomastoid muscle (Fig. 3). After exposure of the internal jugular vein and the accessory nerve, the tip of the transverse process of C1 was identified by blunt preparation. Levator scapulae muscle and obliquus capitis muscle insertions were detached from the transverse process. The vertebral artery
Fig. 6 Intraoperative view before closure
was identified. After opening the C1 vertebral artery foramen, the vessel was mobilized for further resection of the tumor. The tumor was removed stepwise until the C2 joint, the odontoid and the occipital condyle were identified (Fig. 4). The endplates of the joint of C2 and the condyle were carefully removed for later fusion. At the end, an intraoperative 3D scan verified the complete resection of the tumor before a Harms cage filled with chips from human demineralized bone matrix (DBM) was inserted. Further DBM was put laterally to the cage (Fig. 6). Before closing, another 3D scan was performed showing the right positioning of the Harms cage (Fig. 5). The skin was closed
Fig. 5 3D scan after positioning of the Harms cage
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Eur Spine J
Fig. 7 Postoperative X-ray control
in a multilayer fashion without any drain. A postoperative X-ray recorded the result of the operative procedure and the follow-up (Fig. 7). Histology The histological examination revealed a nodular plasmocytoma with severe degradation of cancellous and cortical bone. Postoperative course During the first days after surgery the patient suffered from a transient peripheral palsy of the auriculus oris muscle and a hypesthesia of the right earlobe. No additional neurological deficit was observed. At 6-week follow-up, the palsy had disappeared completely. The patient received supportive oncological therapy for the plasmocytoma.
using this approach. In contrast to the paper from Shucart and Kleriga [6] who were orientated to the spinal canal, this approach exposes the ventral aspect of the upper cervical spine. After bone resection this approach allows also a cage implantation. Potential complications with this procedure include injury to the spinal accessory nerve and the vertebral artery. Therefore, CT angiography is recommended preoperatively. The accessory nerve which is running with the jugular vein can be identified early. Injury of the nerve occurs much more from stretching of the vessel by excessive retraction than by cutting. After blunt preparation the first landmark for locating the vertebral artery is the prominent lateral process of C1 which is located directly over the vertebral canal. Once the vertebral artery is identified the vertebral canal can be opened for mobilization of the vessel. Conflict of interest interest.
None of the authors has any potential conflict of
Discussion References A plasmocytoma is mostly found localized to the thoracic and lumbar spine. The cervical spine is rarely affected at an advanced state [3]. No preoperative examination clarified the origin of the osteolysis. Indication for surgery was the treatment of severe neck pain and the progressive lateral bending of the head related to the destruction of the lateral mass. The lateral approach presented here provides excellent exposure of the lateral and ventral portions of the lateral mass of C1 including the odontoid. Also lesions between the condyles and C2 vertebral body can be treated
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1. Abdullah KG, Schlen RS, Krishnaney A, Steinmetz MP, Benzel EC, Mroz TE (2012) Direct lateral approach to pathology at the craniocervical junction: a technical note. Neurosurg 70:202–208 2. Apuzzo M, Weiss MH, Heiden JS (1978) Transoral exposure of the atlantoaxial region. Neurosurg 3:201–207 3. Freyschmidt J, Ostertag H, Jundt G (2010) Knochentumoren–– Klinik, Radiologie, Pathologie, 3rd edn. Springer, BerlinHeidelberg 4. Kuettner H (1917) Die Verletzungen und traumatischen Aneurysmen der Vertebralgefa¨ße am Halse und ihre operative Behandlung. Beitr klin Chir 108:1–60
Eur Spine J 5. McDonnell D (1991) Anterolateral cervical approach to the craniovertebral junction. In: Rengachery SS, Wilkins RH (eds) AANS operative Atlas, vol 1. Williams and Wilkins, Baltimore, pp 147–164 6. Shucart WA, Kleriga E (1980) Lateral approach to the upper cervical spine. Neurosurg 6:278–281 7. Singh H, Harrop J, Schiffmacher P, Rosen M, Evans J (2010) Ventral surgical approaches to craniovertebral junction chordomas. Neurosurg 66:96–103
8. Zorzon M, Skrap M, Diodato S, Nasuelli D, Lucci B (2001) Cysts of the atloantoaxial joint: excellent long-term outcome after posterolateral surgical decompression. Report of two cases. J Neurosurg Spine 95:111–114
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CASE REPORT
Lateral mass lesions of the C1 vertebra: a modified ‘‘far lateral’’ approach Michael Winking
Received: 7 May 2013 / Revised: 22 December 2013 / Accepted: 22 December 2013 Ó Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose The surgical removal of lateral mass lesions is demanding due to their close anatomical relationship with the vertebral artery, upper spinal cord as well as overlying muscular structures. Usually a dorsal approach will be performed to reach the lateral mass. The disadvantage of this approach is the extensive mobilization of the neck muscles required to allow exposure of the lateral mass, which can be accompanied by severe muscular atrophy due to the damage of the local innervation. Additionally, management of the exposure of the vertebral artery is hindered by the dorsal approach. Methods A modified ‘‘far lateral’’ approach with complete resection of the lateral mass of C1 followed by a substitute with a Harms cage is presented. Results A 54-year-old woman was suffering from severe neck pain accompanied by a progressive sliding of her head and the visual axis to the right hand side. MRI as well as CT scans showed an osteolytic destruction of the right lateral mass of C1. After occipito-cervical fusion the osteolytic lateral mass was removed using a far lateral approach to the upper cervical spine. The patient recovered immediately after surgery, the neck pain improved and the lateral bending of the head was balanced. Conclusions This far lateral approach offers the advantage of direct visualization of the lateral aspect of the upper cervical spine with the opportunity for local stabilization at the center of rotation. Keywords Lateral mass C1 Osteolytic destruction Far lateral approach M. Winking (&) ZW-O Spine Center Osnabrueck, Am Finkenhuegel 3, 49076 Osnabrueck, Germany e-mail: [email protected]
Introduction Laterally placed lesions in the upper cervical spine present technical problems for removal. A ventral approach is adequate for pathologies localized in the vertebral bodies, the discs or the spinal cord. In the C1–C2 region those approaches have to be done transorally [2]. Resection of the lateral mass of C1 including preparation of the vertebral artery is very limited using this approach. Using a retropharyngeal approach you can reach the lateral mass passing the submandibular gland, cutting parts of the digastric muscle and mobilizing the hypoglossal nerve. This approach is demanding because there are several anatomical structures at risk [5]. A dorsal approach has advantages in that it allows exposure of the dorsal aspect of the spinal canal or the dorso-lateral region of the vertebra [7, 8]. For pathologies of the lateral mass this technique is also limited. The vertebral artery leaves the vertebral canal far laterally with a loop before entering the foramen magnum. This will be identified at the end of the preparation from the dorsal side. Significant traction on the paravertebral muscles is necessary to expose the transverse process of C1. This is associated with the risk of damage to local innervation of the paravertebral muscles. Already in 1917 a lateral approach to the upper cervical spine was described for treatment of vertebral artery aneurysms [4]. This approach was adapted for surgery in the ventral portion of the spinal canal from the foramen magnum to the superior portion of C3 [6]. Using this approach an incision is made at the anterior border of the sternocleidomastoid muscle. After identification of the tip of the transverse process of C1 and muscle detachment, the C1 lamina is resected for intraspinal tumor removal [1]. This approach is orientated to the ventral part of the spinal canal. In this paper we describe a modification, which is able to expose the whole C1 vertebra from the lateral side.
123
Eur Spine J Fig. 1 Preoperative axial CT and MRI scan showing the osteolytic destruction of the C1 vertebral body. The white arrows indicate the tumor mass
Fig. 3 The skin incision marked from the right suboccipital region to the ventral side of the sternocleidomastoid muscle. Right earlap is fixed by sutures head is fixed by Mayfield clamp with a slight flexion to the left side Fig. 2 Preoperative 3D reconstruction of the upper cervical spine. Arrows indicate the destruction of the right lateral mass of C1
Case report History We present the case of a 54-year-old woman complaining of neck pain in the upper cervical region accompanied by progressive lateral bending of her head. Pain was intensified by rotation of the head as well as by flexion and extension. There was no radicular pain, no palsy, but a slight hypesthesia in the forearm on the right hand side. Comorbidities included chronic pancreatitis and ulcerative colitis but no history of tumor. Complete laboratory examination, including tumor markers as well gammopathy diagnostics, was without abnormalities. A bone marrow biopsy was assessed as unremarkable.
123
Imaging MR and CT imaging studies showed an osteolytic destruction of the right lateral mass not crossing the midline of C1 but destroying the cortical bone (Figs. 1a, b, 2). The perfusion of both vertebral arteries was assessed using angiography. Additional occlusion testing of the right vertebral artery was tolerated without permanent or transient neurological symptoms. A full body CT for tumor staging revealed no further malignancies. Surgical technique Because the lesion was destroying the lateral mass, a resection combined with stabilization was planned. During the first step an occipito-cervical fusion was performed using a dorsal screw rod system with an occipital plate. Because of the destruction of the lateral mass with the loss
Eur Spine J
Fig. 4 Intraoperative view after removal of the lateral mass of C1
of axial loading capacity, a local cage stabilization between C0 and C2 was planned for the second step (Fig. 2). For this purpose, a modified far lateral approach was chosen. The patient was positioned in a left lateral position with the head slightly flexed downwards. A hockey stickshaped skin incision was performed starting at the mastoid and running on the ventral side of the sternocleidomastoid muscle (Fig. 3). After exposure of the internal jugular vein and the accessory nerve, the tip of the transverse process of C1 was identified by blunt preparation. Levator scapulae muscle and obliquus capitis muscle insertions were detached from the transverse process. The vertebral artery
Fig. 6 Intraoperative view before closure
was identified. After opening the C1 vertebral artery foramen, the vessel was mobilized for further resection of the tumor. The tumor was removed stepwise until the C2 joint, the odontoid and the occipital condyle were identified (Fig. 4). The endplates of the joint of C2 and the condyle were carefully removed for later fusion. At the end, an intraoperative 3D scan verified the complete resection of the tumor before a Harms cage filled with chips from human demineralized bone matrix (DBM) was inserted. Further DBM was put laterally to the cage (Fig. 6). Before closing, another 3D scan was performed showing the right positioning of the Harms cage (Fig. 5). The skin was closed
Fig. 5 3D scan after positioning of the Harms cage
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Eur Spine J
Fig. 7 Postoperative X-ray control
in a multilayer fashion without any drain. A postoperative X-ray recorded the result of the operative procedure and the follow-up (Fig. 7). Histology The histological examination revealed a nodular plasmocytoma with severe degradation of cancellous and cortical bone. Postoperative course During the first days after surgery the patient suffered from a transient peripheral palsy of the auriculus oris muscle and a hypesthesia of the right earlobe. No additional neurological deficit was observed. At 6-week follow-up, the palsy had disappeared completely. The patient received supportive oncological therapy for the plasmocytoma.
using this approach. In contrast to the paper from Shucart and Kleriga [6] who were orientated to the spinal canal, this approach exposes the ventral aspect of the upper cervical spine. After bone resection this approach allows also a cage implantation. Potential complications with this procedure include injury to the spinal accessory nerve and the vertebral artery. Therefore, CT angiography is recommended preoperatively. The accessory nerve which is running with the jugular vein can be identified early. Injury of the nerve occurs much more from stretching of the vessel by excessive retraction than by cutting. After blunt preparation the first landmark for locating the vertebral artery is the prominent lateral process of C1 which is located directly over the vertebral canal. Once the vertebral artery is identified the vertebral canal can be opened for mobilization of the vessel. Conflict of interest interest.
None of the authors has any potential conflict of
Discussion References A plasmocytoma is mostly found localized to the thoracic and lumbar spine. The cervical spine is rarely affected at an advanced state [3]. No preoperative examination clarified the origin of the osteolysis. Indication for surgery was the treatment of severe neck pain and the progressive lateral bending of the head related to the destruction of the lateral mass. The lateral approach presented here provides excellent exposure of the lateral and ventral portions of the lateral mass of C1 including the odontoid. Also lesions between the condyles and C2 vertebral body can be treated
123
1. Abdullah KG, Schlen RS, Krishnaney A, Steinmetz MP, Benzel EC, Mroz TE (2012) Direct lateral approach to pathology at the craniocervical junction: a technical note. Neurosurg 70:202–208 2. Apuzzo M, Weiss MH, Heiden JS (1978) Transoral exposure of the atlantoaxial region. Neurosurg 3:201–207 3. Freyschmidt J, Ostertag H, Jundt G (2010) Knochentumoren–– Klinik, Radiologie, Pathologie, 3rd edn. Springer, BerlinHeidelberg 4. Kuettner H (1917) Die Verletzungen und traumatischen Aneurysmen der Vertebralgefa¨ße am Halse und ihre operative Behandlung. Beitr klin Chir 108:1–60
Eur Spine J 5. McDonnell D (1991) Anterolateral cervical approach to the craniovertebral junction. In: Rengachery SS, Wilkins RH (eds) AANS operative Atlas, vol 1. Williams and Wilkins, Baltimore, pp 147–164 6. Shucart WA, Kleriga E (1980) Lateral approach to the upper cervical spine. Neurosurg 6:278–281 7. Singh H, Harrop J, Schiffmacher P, Rosen M, Evans J (2010) Ventral surgical approaches to craniovertebral junction chordomas. Neurosurg 66:96–103
8. Zorzon M, Skrap M, Diodato S, Nasuelli D, Lucci B (2001) Cysts of the atloantoaxial joint: excellent long-term outcome after posterolateral surgical decompression. Report of two cases. J Neurosurg Spine 95:111–114
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