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I Nurliza¹, SHA Primuharsa Putra² , R Roszalina³, L Saim⁴ , M Zahiah⁵

ABSTRACT

We present two cases of direct traumatic carotico-cavernous fistula following motor vehicle accident. Their main symptoms include loss of vision, progressive proptosis and recurrent epistaxis. Angiogram confirmed presence of carotico-cavernous fistula in both cases. One was successfully treated by open surgery and the other by embolization with Guglielmi detachable coils (GDC). In both cases, proptosis and epistaxis resolved completely.

KEY WORDS: carotico-cavernous fistula, epistaxis, surgery, embolization, Guglielmi detachable coils.

INTRODUCTION

Carotico-cavernous fistula (CCF) is characterized by abnormal arteriovenous shunting within the cavernous sinus. It is a rare condition and mostly occurs after craniofacial trauma. The classic presentation involves pulsatile exopthalmos, bruit, chemosis and visual disturbances. They can present with severe recurrent epistaxis requiring urgent Ear, Nose and Throat referral. The symptoms may occur immediately or may be delayed for days or weeks post-trauma. A number of treatment options have been described. Selective embolization is the treatment of choice.

Case Report

Case 1

An 18-year-old young man who suffered from head injury in a motor vehicle accident in September 1996 presented with recurrent severe epistaxis. He lost his vision and noted progressive bulging of the right eye since the accident. His general examination was satisfactory. The right eye was proptosed with congested vessels of the conjunctiva, however no thrill and bruit was noted. There was total right opthalmoplegia. Nasal endoscopy was however, normal. Angiogram confirmed a CCF. There was a good cross-over flow from the left to the right hemicerebrum. The ophthalmic vein was grossly dilated on the right. Right internal carotid artery ligation was done in December 1996. He was symptoms-free for 6 months but the epistaxis recurred spontaneously. He was then referred to the neurosurgeon whereby clipping of the right supraclinoid carotid artery was performed via a pterional craniotomy. He was discharged well. On follow-up, the proptosis resolved and there was no more epistaxis. However, his right eye remains blind.

Case 2

A 49-year-old man was presented to our clinic with recurrent severe epistaxis for four years. He was involved in a motor vehicle accident in 1993 whereby he sustained fracture of frontal bone with intracranial bleeding. He lost his vision on the left since then. He noticed dilated veins slowly appearing over the forehead and proptosis of the left eye three months post-trauma. He had one episode of epistaxis in 1998. Angiogram revealed a CCF. At that time, he refused any intervention and defaulted follow-up. He returned to the hospital when he developed a few severe episodes of epistaxis in 2002. There were dilated veins over the supraorbital area with bruit and thrill present (Fig. 1). The left eye was proptosed with total opthalmoplegia. Nasal endoscopy, however was normal.

Figure 1 : Proptosis of the left eye with opthalmoplegia.Note dilated veins on the nasion and forehead.

Repeat angiogram revealed a large CCF with grossly dilated left superior opthalmic artery (Fig. 2). The right internal carotid artery supplies both the right and left hemicerebrum. The left ophthalmic vein was grossly dilated and tortuous.

Figure 2: Left cerebral angiogram showing coil and ballon in the cavernous sinus during the embolozation (short arrow) and dilated superior ophthalmic artery(long arrow).

He underwent embolization with Guglielmi detachable coil (GDC) since it was a less invasive procedure but failed to occlude the whole fistula and this was repeated with a detachable silicon balloon and GDC two weeks later. He was clinically cured post-embolization (Fig. 3). On follow-up, epistaxis, proptosis, bruit and dilated veins on his forehead was completely resolved. However, the left eye remains blind

Figure 3: Post-embolization

DISCUSSION

The incidence of CCF is thought to be 0.17 to 1% of blunt craniofacial injury. They are frequently associated with basilar skull fracture. ¹ Direct fistulae between the intra-cavernous carotid artery and the cavernous sinus are uncommon but well-described complications of cranial base trauma that occur in 0.2 to 0.3% of patients with craniofacial trauma. ²

Post-traumatic CCF occurs as a result of laceration of the internal carotid siphon or one of its intra-cavernous branches. It involves a direct connection (Barrow type A) between internal carotid artery and the cavernous sinus forming a high-pressure and high-flow fistula. Irrespective of the aetiology and location of CCF, shunting of blood between a high-flow arterial system and low-flow venous system produces increased vascular pressure and resistance in the venous system. This increased venous pressure impedes the venous drainage of the cavernous sinus, thereby causing a “back-up” and vascular congestion in the regions that are normally drained by the cavernous sinus, such as the orbits. This congestion within and around the cavernous sinus accounts for the clinical symptoms and possible adverse sequela of CCF as shown in these cases.³

The clinical manifestation depends on the venous drainage of the fistula either anteriorly via opthalmic venous system or posteriorly via inferior petrosal sinus. Even though most cases involved mixed drainage, but both of our cases arise from the anterior venous drainage alone.

In the literature, the clinical presentations that have been described include proptosis (94%), pulsating exopthalmos (40%), bruit (75%), orbital frontal headache and orbital pain (40%), chemosis (71%) extraocular palsy and diplopia (60%), loss of visual acuity (46%) and 5^th cranial nerve involvement (24.6%). ⁴ They may also present with recurrent epistaxis caused by venous distension in the naso-orbital regionas shown in this case report.⁵

Diagnosis is usually made from clinical examination. Computed tomography (CT) scan revealed marked enhancement of the cavernous sinus, prominent ophthalmic veins or extraocular muscle congestion. ¹

Arteriography is the confirmatory test of choice. It is helpful in identifying the fistula, evaluate venous drainage of the CCF, document collateral circulation and recognize any other vascular lesion present ¹.

Most post-traumatic CCF can be treated on an elective basis. Emergency treatment is for patient with progressive visual loss, severe epistaxis or sphenoid sinus aneurysm. ² Other indications include intractable headache, intolerable bruit, extra ocular muscle palsy and cosmetically offensive chemosis.

The goal of therapy is to obliterate the fistula without interruption of the internal carotid circulation that may lead to cerebral infarction.

There are a few treatment options described. These include proximal ligation of the internal carotid artery, trapping procedure by ligating the internal carotid artery in the neck and intracranially above the fistula with or without ophthalmic artery occlusion. Newer approaches include selective embolization of the defect using a variety of materials via arterial or venous approach. Both of our patients were treated with two different modalities. One had surgical ligation and the other had embolisation.

The inherent problem with surgical ligation includes sacrificing the internal carotid artery, which carries a high risk of vision loss, recurrence, and stroke.

Treatment of CCF has dramatically changed with the evolution of interventional radiography. Endovascular treatment is an established therapeutic alternative to direct surgery in selected cases and the current treatment of choice for both traumatic and spontaneous fistulae. The obvious advantages of this approach is the avoidance of general anaesthesia, craniotomy and brain manipulation. ⁶ It involved transfemoral introduction of the catheter into the carotid artery and selectively closes the fistula without interrupting the internal carotid artery circulation.

Of the varied embolisation materials used to obliterate the aneurysm, the very soft electrically detachable platinum coils which was described by Guglielmi et al in 1992 are much less traumatic when compared to balloons.³ These new coils can be placed and replaced several times until an ideal position is achieved. They are then detached by electrolysis, which further enhances the process of thrombosis at the fistula site. The ability to remove, reposition and detach a coil was the most significant advantage of the coil design which is crucial to the safe practice of interventional neuroradiology. ⁶ These coils are able to adapt to the shape of the aneurysm without increasing the intra-aneurysmal pressure significantly ⁷. This property also reduces the risk of aneurysm rupture during embolisation. ⁶

CONCLUSION

Carotico-cavernous fistula is a rare condition but can be life threatening. The treatment has changed towards embolization and this has significantly reduced morbidity. However if embolization failed, surgical approach still remains an option.

REFERENCES

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3. Fattahi TT, Brandt MT, Jenkins WS et al. Traumatic carotid-cavernous fistula: Pathophysiology and Treatment. J Craniofac Surg 2003; 14 (2): 240-246.

4. Garland SD, Maloney P, Doku HC. Caroticocavernous sinus fistula trauma to the head. J Oral Surg 1977; 35: 832

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6. Tan LTH, Kwok CKJ, Lam HS. Early experience with surgically inaccessible wide-necked intracranial aneurysm embolised with Guglielmi electrically detachable coils and electrothrombosis. Singapore Med J 1996; 37 (5) : 549-552.

7. Guglielmi G, Vinuela F, Briganti F et al. Carotid-cavernous fistula caused by a ruptured intracavernous aneurysm: endovascular treatment by electrothrombosis with detachable coils. Neurosurgery 1992; 31: 591-596.

Post-traumatic Carotico-cavernous fistula: A report of two cases.