The Neuroradiology Journal 20: 566-569, 2007

www. centauro. it

Surgical Treatment of Cervical Arteriovenous Fistula in a Patient with Neurofibromatosis Type 1. A Case Report

A. GUZEL*, M. TATLI*, U. ER**, A. KAZANCI**, H.M. OZTURK***, D. BELEN * Neurosurgery Department, Dicle University; Diyarbakir, Turkey ** Neurosurgery and *** Radiology Clinics, Ministry of Health Diskapi Education and Research Hospital; Ankara, Turkey Key words: arteriovenous fistula, cervical spine, embolization, neurofibromatosis type 1, surgery

SUMMARY – Vasculopathies are frequently associated with neurofibromatosis type-1, and they are generally occlusive or stenotic type lesions. Vertebral arteriovenous fistula (AVF) is quite rare in neurofibromatosis type 1 patients. They can be treated with surgical excision or endovascular occlusion. We describe a surgically treated cervical AVF in a neurofibromatosis type 1 (NF-1) patient and discuss the selection of the patient for the surgery. Although endovascular occlusion is the first line treatment option for cervical AVFs, some selected cases can be successfully treated by surgery. Surgery should be considered as a treatment option in spite of its risks, especially for cervical AVF which is associated with fibromuscular system diseases like NF-1.

Introduction Vasculopathies are frequently associated with neurofibromatosis type-1 (NF-1) 1,2,3 and they are generally occlusive or stenotic type lesions 4,5,6. Vertebral arteriovenous fistula (AVF) is a rare abnormal shunting between the extracranial vertebral artery (VA) or one of its branches and a nearby vein or epidural venous plexus 7. Vertebral AVFs usually occur by trauma, and their spontaneous occurence is hardly ever seen. Spontaneous AVFs are congenital lesions, and they are associated with fibromuscular dysplasia, Ehlers Danlos syndrome or Neurofibromatosis 8. A mild trauma, a cough that increases intracranial pressure, gunshot-wounds or penetrating wounds may result in cervical AVF 2. Vertebral AVFs lead to ischemia of the spinal cord by arterial steal syndromes or myelomalasia by their mass effects 5,7. AVFs can be treated with surgical excision or endovascular occlusion. The aim of the endovascular treatment is to abolish fistulous flow and the drainage vein by selective occlusion, besides protecting the VAs 3. A detachable balloon is the preferred way of endovascular 566

occlusion. In surgery, the fistulous structure is excised by cutting and coagulating feeders and drainage veins. Then an attempt is made to excise it completely. Case Report A 36-year-old man was admitted to the hospital with a three month history of progressive weakness of his legs and arms, pain in his left arm and one month history of hoarseness. His medical history was unremarkable except for widespread neurofibromas (figure 1). Neurological examination revealed quadriparesis in 1/5 muscle strength, hypoactive deep tendon reflexes and a loss of anal sphincter tonus. A cervical spine magnetic resonance imaging (MRI) study showed signal void of serpiginous structures from the level of the CVJ to the C5 vertebral level presenting vascular anomalies. Cervical spinal cord was compressed by anomalic vascular structures. Myelomalasic changes at C2-3 vertebral level characterized by increased signal intensity on T2-W image and swelling below the level of the compression were seen (figure 2). Angiography by subclavian artery in-

A. Guzel

Surgical Treatment of Cervical Arteriovenous Fistula in a Patient with Neurofibromatosis Type 1

Figure 1 Widespread neurofibromas of the patient.

Figure 2 T2-W image at the midsagittal region discloses signal void of serpiginous structures from the level of the CVJ to the C5 vertebral level presenting vascular anomalies. Cervical spinal cord is compressed by anomalic vascular structures. Myelomalasic changes at C2-3 vertebral level characterized by incresased signal intensity on T2-W image and swelling below the level of the compression are seen.

A

B

Figure 3 Subclavian artery injection (AP view) demonstrates AV fistula with intensive venous drainage (A), left vertebral artery injection (AP view) shows the right-sided fistula by means of retrograde flows, through the vertebrobasilar junction to the right vertebral artery (B. The fistula level is seen more clearly because of more selective and slower filling.

567

Surgical Treatment of Cervical Arteriovenous Fistula in a Patient with Neurofibromatosis Type 1

A. Guzel

p Figure 5 Lateral cervical flexion roentgenogram shows spinal instability of the C4-5 level. t Figure 4 T1-W image at the midsagittal region shows disappearance of anomalic vascular structures and decompression of the spinal cord.

jection demonstrated AV fistula with intensive venous drainage, and left VA injection showed the right sided fistula by means of retrograde flows, through the vertebrobasilar junction to the right VA. The fistula level was seen more clearly because of more selective and slower filling (figure 3 A,B). Under general anesthesia, C1 to C5 laminectomies were performed in prone position. The left VA was ligated at its proximal region which arose from the truncus brachiocephalicus. Then the right VA was clipped where it enters the cranium with an aneurysm clip via paramedian suboccipital craniectomy. The external feeder from the external carotid artery was also ligated at the distal portion of the thyrocervical branch. The abnormal vascular rete was seen on the dura. It was coagulated and excised. Histopathological examination revealed an arteriovenous malformation. Postoperative MRI showed disappearance of anomalic vascular structures and decompression of the spinal cord (figure 4). Paresis of the patient was improved immediately after the operation with 4/5 muscle strength. Ten days later, his hoarseness had subsided. 568

The patient started suffering from neck pain in the fourth postoperative month. Lateral cervical plain roentgenogram showed postlaminectomy kyphotic deformity (figure 5). An anterior stabilization with bony fusion was performed. The patient was discharged with an uneventful postoperative period. Discussion NF goes along with mesodermal and neuroectodermal dysplasia 3. The purpose of the frequent occurance of vasculopathies in NF-1 is the increasing proliferation of the smooth muscle of blood vessel walls 4. Therefore, 85% of the associated vascular anomalies in NF-1 are stenotic or occlusive type lesions 2,4,6. Another theory is the development of a fistula between the venous structures and a developed aneurysm in the weakened vessel walls by mesodermal dysplasia or neurofibromatosis 4 . As the surgery is difficult and it is traumatic for the patient, endovascular occlusion should be preferred initially for treatment of a cervical AVF. The preservation of the patency of the

www. centauro. it

affected VAs is an advantage of the endovascular approach 5. But VAs cannot always be protected. Fistulas with wide holes can be faced with developing pseudoaneurysm that cannot be treated selectively. Inflating a balloon in the pseudoaneurysm resulted in widening the aneurysm without occlusion of the fistula. In such a situation, occlusion cannot be achieved without sacrifying the VA. In addition to this, there will be rupture of the vessels during embolization of the associated vasculopathies in NF-1, because of highly fragile vessels in such diseases 8. If a rupture occurs during this process, it can result in mortality or a severe morbidity. On the other hand, the mass effects of large fistulas, as in our case, can be eradicated excellently by surgery. If myelomalasia of mass effect of the fistula is suspected, surgical treatment should be considered especially in the NF1 patient. Another important issue in this case is the development of kyphotic deformity after surgery. Scoliosis, kyphotic deformity, pseu-

The Neuroradiology Journal 20: 566-569, 2007

doarthroses and numerous vertebral anomalies are seen frequently in NF-1 patient 3,6,9. But, in our patient, kyphotic deformity occurred after laminectomy. Another operation to stabilize and correct the spine was needed. This is a severe disadvantage of the surgery. Decision of the surgery should be tailored to the patient considering long-term unwanted effects as well as immediate complications. Conclusion Although endovascular occlusion is the first line treatment option for cervical AVFs, some selected cases can be treated successfully via surgery in highly experienced neurosurgery clinics. Surgical treatment should be considered as one of the treatment alternatives in spite of its risks, especially cervical AVF which is associated with fibromuscular system diseases like NF-1.

References 1 Giuffre R, Sherkat S: Maldevcelopmental pathology of the vertebral artery in infancy and childhood. Child’s Nerv Syst 16: 627-632, 2000. 2 Kahara V, Lehto U, Ryymin P et Al: Vertebral epidural arteriovenous fistula and radicular pain in neurofibromatosis type I. Acta Neurochir 144: 493-496, 2002. 3 Maheshwari S, Kale HA, Desai SB et Al: Magnetic resonance imaging findings in an unusual case of atlantoaxial dislocation and vertebral artery-vein fistulas in a patient of neurofibromatosis-1. Australasian Radiology 46: 316-318, 2002. 4 Kubota T, Nakai H, Tanaka T et Al: A case of intracranial aretriovenous fistula in an infant with neurofibromatosis type 1. Child’s Nerv Syst 18: 166-170, 2002. 5 Siddhartha W, Chavhan GB, Shrivastava M et Al: Endovascular treatment for bilateral vertebral arteriovenous fistulas in neurofibromatosis 1. Australasian Radiology 47: 457-461, 2003. 6 Koenigsberg RA, Aletich V, Debrun G et Al: Cervical vertebral arteriovenous fistula balloon embolization in a patient with neurofibromatosis type 1. Surg Neurol 47: 265-73, 1997. 7 Wada K, Ohtsuka K, Terayama K et Al: Neurofibromatosis with spinal paralysis due to arteriovenous fistula. Arch Orthop Trauma Surg 108: 322-4, 1989. 8 Ushikoshi S, Goto K, Uda K et Al: Vertebral arteriovenous fistula that developed in the same place as a

previous ruptured aneurysm: a case report. Surg Neurol 51: 168-173, 1999. 9 Isu T, Miyasaka T, Abe H, Ito T, Iwasaki Y, Tsuru M, Kitaoka K, Tsunoda M: Atlantoaxial dislocation associated with neurofibromatosis. Report of three cases. J Neurosurg 58: 451-3, 1983.

Uygur ER, MD Sogutozu Caddesi, 4th Sokak, 22-7 06470, Ankara, Turkey Tel: +90 312 284 11 51 Fax: +90 312 517 31 44 E-mail: [email protected]

569

Surgical treatment of cervical arteriovenous fistula in a patient with neurofibromatosis type 1. A case report.

Vasculopathies are frequently associated with neurofibromatosis type-1, and they are generally occlusive or stenotic type lesions. Vertebral arteriove...
300KB Sizes 0 Downloads 0 Views