Radiology Abstract Objective. To determine the effi- ciency of latex detachable balloons in the treatment of post-traumatic carotid-cavernous fistulae (CCF). Methods. Management and outcome were reviewed for 34 consecutive patients with post-traumatic CCF personally treated by one of the authors (PS) using latex detachable balloons during the 4-year period 1996 - 2000. Results. Endovascular embolisation of 34 CCFs was attempted in 33 patients. In 1 patient where the fistula was a result of rupture of an intra- cavernous aneurysm, the fistula thrombosed spontaneously before embolisation was attempted. In the 33 treated patients, the fistula was occluded in 30 cases (91%). Patency of the internal carotid artery was pre- served in 16 cases (53%). Conclusion. A high percentage (91%) of direct CCFs were success- fully occluded with latex detachable balloons. There were no permanent neurological complications in any of the patients treated. Introduction A carotid-cavernous fistula (CCF) is an abnormal connection between the carotid artery and the surround- ing cavernous sinus. CCFs are usual- ly classified in three ways: (i) patho- logically (or aetiologically), as sponta- neous or traumatic; (ii) haemo- dynamically, into high-flow or low- flow; or (iii) angiographically, as direct or indirect. The Barrow angiographic classifi- cation is most commonly used. It is based on the pattern of arterial sup- ply and has therapeutic implica- tions.1-3 This allows CCFs to be placed into one of four angiographic categories as follows: Type A fistulae (direct) have abnormal connections (or shunts) between the internal carotid artery (ICA) and cavernous sinus. Types B, C and D are all indirect (or dural) fistulae. The angioarchitec- ture of these is analogous to dural arteriovenous fistulae (AVFs) occur- ring in other locations. Type B fistulae are shunts between meningeal branches of the ICA and the cavernous sinus. Type C are shunts between meningeal branches of the external carotid artery (ECA) and the cav- ernous sinus. Type D are shunts between meningeal branches of both the ECA and the ICA and the cavernous sinus. Direct connections between the ICA and the cavernous sinus may occur as a consequence of blunt or penetrating trauma, ruptured intra- cavernous carotid aneurysms, colla- gen deficiency syndromes (such as Ehlers-Danlos IV syndrome), fibro- muscular dysplasia and arterial dis- section.2-4 Causes of the indirect type are often unknown, but may be related to pregnancy, undisclosed or minor trauma, surgical procedures and cav- ernous sinus thrombosis.1,5 The symptoms caused by direct CCFs are related to the size, location, duration, route of venous drainage and presence of arterial and venous collaterals. The clinical features of direct, high-flow CCFs include proptosis, conjuctival oedema, orbital bruit, progressive visual deterioration and cranial nerve palsies. Some low-pres- sure CCFs present with progressive symptoms mainly affecting the eye. Features of indirect CCFs are similar to those of direct CCFs but as indi- ORIGINAL ARTICLE 4 SA JOURNAL OF RADIOLOGY • February 2005 Endovascular treat- ment of post- traumatic carotid- cavernous fistulae using latex detach- able balloons P Szkup MD, FCRad (Diag) SA, MMed (UCT) Department of Medical Imaging Royal University Hospital University of Saskatchewan Canada S Beningfield MB ChB (UCT), FFRad D (SA) Department of Radiology Groote Schuur Hospital University of Cape Town Radiology 2/24/05 4:50 PM Page 4 rect CCFs are usually chronic they seldom lead to visual deterioration. The goals of treatment are the elimination of the fistula, ideally with preservation of the patency of the ICA, at the same time avoiding cra- nial nerve palsies and other compli- cations (Fig. 1). The treatment options for CCFs have undergone significant evolution. Surgical and endovascular techniques have been described for the closure of both direct and indirect CCFs. These include surgical carotid artery occlusion, trapping procedures (such as clipping of the supraclinoid and cervical parts of the ICA) and direct surgical exposure of the CCF with surgical closure of the fistula. Embolisation with coils, cyanoacry- late, blood clot and detachable bal- loons are some endovascular options. 6-9 In 1971 Prolo and Hanberry7 first reported successful occlusion of CCFs with non-detach- able balloons. Although this tech- nique required sacrifice of the ICA, ischaemic complications were less common than encountered with rou- tine carotid ligation. In 1973 Parkinson6 reported direct surgical repair of a CCF with preservation of the ICA flow, but the procedure was technically difficult, required cardiac arrest and was asso- ciated with significant neurological morbidity. In 1974 Mullan10 introduced sur- gical packing of the cavernous sinus using thrombogenic materials such as gelatin sponge (‘gelfoam’), oxidised cellulose, cotton or bronze wire placed via surgical transvenous routes. In December 1969, Serbinenko successfully performed occlusion of a direct CCF and the affected ICA using a self-made sili- cone detachable balloon placed via a common carotid artery puncture.11,12 This balloon was inflated at the target site with a radio-opaque mixture of polymer and tantalum powder to create a material that gradually became a stable gel within the bal- loon and distal catheter lumen. This allowed the catheter to be severed using the cutting edge of the arterial needle, leaving the catheter segment still attached to the inflated balloon in the thrombosed arterial lumen. Unfortunately the silicone poly- mer proved to be highly viscous, often preventing balloon deflation where the balloon position was not satisfactory on trial inflations. This technique was improved by perform- ing initial test inflation of the balloon with less viscous iodinated contrast material in order to determine whether the position of the balloon was satisfactory. Once correct place- ment was confirmed, the contrast medium was aspirated and silicone polymer was then injected into the balloon. Serbinenko subsequently devel- oped a balloon with an ingenious valve mechanism that allowed the 6 SA JOURNAL OF RADIOLOGY • February 2005 ORIGINAL ARTICLE Fig. 1a. Lateral internal carotid angiogram show- ing fistula with preferential venous drainage via dilated superior ophthalmic vein (arrow). Fig. 1b. Frontal left internal carotid angiogram showing unusually well demonstrated fistula site (arrow). Fig. 1c and 1d. Frontal and lateral internal carotid angiograms following embolisation with one bal- loon (arrow) and preservation of the carotid artery. Radiology 2/24/05 4:50 PM Page 6 balloon to be detached from its deliv- ery catheter by placing traction on the catheter, without the balloon deflating after detachment. From 1969 to 1972, Serbinenko performed 304 permanent carotid artery occlu- sions with this system, with only 2 deaths.11,12 In 1974, Debrun et al.9,13 devel- oped a latex tie-on detachable bal- loon to occlude direct CCFs. They were able to preserve the ICA in 59% of cases. Subsequently, latex and sili- cone detachable balloons with inter- nal valves were developed, with vari- ous modifications.14 In 1980, transve- nous approaches were developed independently by Debrun et al.15,16 Halbach et al.17 and Higashida et al.18 to treat patients in whom transarteri- al attempts had failed. By 1991 Guglielmi introduced retrievable electrolytically detachable platinum coils and these were later used to occlude CCFs.8 Despite progress in coil technology, transarte- rial embolisation with detachable balloons is still considered the best initial treatment for direct CCFs.2,3,16,18 Patient details and methods Management and outcome were reviewed for 34 consecutive patients with CCFs personally treated by one of the authors (PS) using detachable latex balloons during the 4-year peri- od 1996 - 2000. These patients were treated at Chris Hani Baragwanath and Groote Schuur hospitals in the departments of radiology of the Universities of the Witwatersrand and Cape Town, South Africa. There were 17 men and 17 women ranging in age from 22 to 56 years, with a mean age of 39 years. Other than in case 4, all patients had direct post- traumatic CCFs (Table I). A prominent orbital bruit was heard by the patient and/or the doc- tor, using a stethoscope in every case. The most common initial symptoms were proptosis and chemosis in 31 patients and an isolated abducens nerve palsy on the affected side in 13 patients. Less often, patients com- plained of headache (11 patients) and visual deterioration (10 patients). Radiographic evaluation The initial radiographic evalua- tion consisted of axial computed tomography (CT) of the head, with and without intravenous iodinated contrast material to evaluate the extent of head trauma. Ideally, evalu- ation of skull fractures was per- formed using high-resolution axial and coronal CT through the base of the skull, viewed with bony settings. The presence of a CCF was suspected by detection of any of the following: dilated cavernous sinus, dilated supe- rior ophthalmic vein(s) or the pres- ence of any other prominent drain- ing vein(s). A 4-vessel cerebral angiogram was then obtained to evaluate the loca- tion and extent of any vascular injury, the presence of any collateral supply via the circle of Willis and the pattern of venous drainage. Because most direct CCFs are high-flow fistu- lae, the cavernous sinus is usually immediately opacified on angiogra- phy and the precise communication site is commonly obscured (Fig. 2). The Heuber maneuvre, with injec- tion of the dominant vertebral artery while manually compressing the affected carotid artery is often used for better visualisation of the fistula site. During this maneuvre, the com- pression of the ipsilateral carotid artery allows flow of contrast medi- um via the posterior communicating artery into the cavernous part of the ICA and fistula, showing the fistula site more clearly without excessive overlying contrast (Fig. 3). In all cases, contralateral carotid angiography during compression of the ipsilateral carotid artery was per- ORIGINAL ARTICLE 7 SA JOURNAL OF RADIOLOGY • February 2005 Table I. Aetiology of 33 cases of carotid-cavernous fistulae (N) Blunt trauma Motor vehicle accident 17 Blunt assault 6 Penetrating trauma Knife stab to orbit 5 Gunshot wound to the head 5 Fig. 2a. Lateral internal carotid angiogram showingdirect fistula. Radiology 2/24/05 4:50 PM Page 7 formed to evaluate the presence or absence of cross-flow via the anterior communicating artery, in case the carotid artery with the fistula had to be occluded during the balloon embolisation. The degree of cross- flow into the anterior and middle cerebral arteries was specifically noted. Method Small CCFs may thrombose spontaneously or during diagnostic angiography. This usually only occurs with CCFs with ECA contributions. Manual compression of the ipsilater- al ICA or the draining angular vein can also be used to treat slow-flow fistulae. In this series, initial attempts at manual compression of the ICA proved to be ineffective, as has been found with other high-flow CCFs. All embolisation procedures were performed in the angiography suite by the same radiologist, with the patient under local anaesthesia and sedated as necessary. In 2 cases, patients required deep intravenous sedation performed by an anaes- thetist. A right common femoral artery approach using an appropriately sized vascular introducer sheath was employed in all cases. Eight French (Envoy-Cordis), or 9 or 10- French (Nycomed-Amersham) guiding catheters were used, depending on the size of the balloon used. The 9- French catheter (Nycomed- Amersham) has an internal diameter large enough to accommodate the most commonly used Goldvalve 9 balloon (Nycomed Amersham) with 1.3 ml capacity, and this catheter was therefore used most frequently. The guiding catheter was then positioned in the ICA, at approximately the sec- ond cervical vertebral body level. Five thousand units of heparin were then given intravenously to prevent thrombus formation on the catheter and balloon systems. The detachable Goldvalve balloon system was used in all the cases. The Goldvalve balloon is made of latex with an internal valve to prevent deflation when detached. It also has an internal radio-opaque metal ball in the balloon lumen to permit visu- alisation on fluoroscopy during posi- tioning. The balloon is available in a variety of sizes and shapes, with a numbering system identifying specif- ic models (Table II). The most com- monly used medium-large GVB9 balloon measures 19 x 11 mm when fully expanded, with a capacity of 1.3 ml (Table II). The balloon is manually attached to a coaxial catheter system consisting of paired inner 2-French (red) and outer 3-French (black) catheters (Nycomed-Amersham). The entire system is then passed through the guiding catheter. The space between the coaxial 2/3 French system and guiding catheter is per- fused with pressurised normal saline to prevent thrombus formation. Injections of contrast into the guid- ing catheter around the 2/3 French coaxial system can be made through a 3-way tap. Before the balloon is placed intra- arterially, it is tested in vitro. Using a provided blunt needle, the balloon is 8 SA JOURNAL OF RADIOLOGY • February 2005 ORIGINAL ARTICLE Fig. 2b. Lateral common carotid angiogram follow- ing embolisation with one balloon (arrow) and preservation of the carotid artery. Fig. 3. Lateral vertebral artery angiogram with carotid compression — Heuber maneuvre. Note filling of anterior circulation and fistula via posterior communicating artery. Bullet in the cavernous sinus is visible (arrow). Table II. Sizes of the latex Goldvalve balloons (Nycomed-Amersham) used Goldvalve Volume Inflated diameter No. of balloons balloon no. (ml) (mm) used 9 1.3 19 x 11 23 16 0.8 21 x 8 10 12 2.5 22.5 x 14 3 7 1.0 13 x 13 1 Radiology 2/24/05 4:50 PM Page 8 filled with contrast medium that is diluted to be iso-osmolar, without exceeding the maximum recom- mended volume. The inflated bal- loon is then detached from the nee- dle and checked for integrity of its valve and the absence of wall abnor- mality. The balloon is then attached to the 2-French delivery catheter that has been previously passed through the 3-French catheter, and the bal- loon is then allowed to deflate. The balloon attached to the coaxial 2/3- French delivery system is advanced through the guiding catheter under fluoroscopic guidance into the fistula site. It may be partially inflated with iso-osmolar iodinated contrast agent while attempting entry into the fistu- la. Usually because of the high flow through the fistula, the balloon will spontaneously traverse the tear of the vessel. This is often detected by observing a fluttering motion of the metal marker or balloon on entering the fistula. Once through the fistula, iso-osmolar contrast agent is used to inflate the balloon. When the balloon is inflated in what appears to be the correct position, a diagnostic angiogram is obtained through the guiding catheter to ensure that the fistula is occluded, and ideally that the ICA is patent. The patient is examined neurologically and, if sta- ble, the balloon is detached by trac- tion on the 2-French delivery catheter. This can be combined with counter-traction and stabilisation by advancing the 3-French catheter to the balloon neck. If the ICA has to be sacrificed, the patient is examined for any neurological deficit for 20 min- utes with the balloon inflated. If the patient fails this test, the balloon is deflated immediately. After the proce- dure, the heparin is not corrected with protamine sulfate. The vascular introducer sheath is removed not earlier than 4 hours following heparin administration. Results Endovascular embolisation was attempted in 33 of the 34 patients with CCFs. In 1 patient where the CCF was a result of rupture of an intracavernous aneurysm, the fistula thrombosed spontaneously before embolisation was attempted (case 4). In the 33 treated patients, the fistula was occluded in 30 cases (91%) (Table III). In 27 cases, a single detachable balloon was required to close the fistula. In 3 cases, 3 balloons were required to close the fistula (Table IV). Case 20 needed 3 large 1.3 ml balloons to close a fistula fol- lowing an orbital knife stab wound. Patency of the ICA was preserved in 16 cases (53%). Endovascular treatment failed to occlude the fistula in 3 patients (9%). In the first case (case 5), a partially inflated balloon was accidentally detached during manipulation in a very tortuous ICA. The balloon lodged in the petrous part of the ICA. The patient was immediately taken for surgery where a trapping procedure with clipping of the supra- clinoid part of the ICA was per- formed, and the fistula subsequently thrombosed. The patient had good cross-flow from the contralateral carotid artery and suffered no per- manent neurological deficit. The sec- ond patient (case 6) had a very tortu- ous carotid artery that was not possi- ble to navigate with the balloon. The inferior petrosal sinus was not visu- alised during diagnostic angiography and as this prevented a venous approach to the fistula, the patient was submitted to surgery where the fistula and ICA were occluded by occluding the supraclinoid and cervi- cal parts of the ICA. In the final patient (case 29) with a mixed direct and indirect CCF following a facial gunshot, the proximal ICA was already occluded by the trauma. The CCF was supplied by the retrograde flow from intracranial arteries. The inferior petrosal sinus was not visu- alised on angiography of the con- tralateral carotid artery. An unsuc- cessful attempt was made to occlude the fistula by means of surgical expo- sure of the facial and superior oph- thalmic veins. In 1 patient (case 32), 2 initial bal- loons ruptured during inflation in the cavernous sinus, most likely due to the presence of sharp bony spicules in the cavernous sinus, although high-resolution CT of the base of the skull failed to visualise any such abnormality. The third bal- loon was placed in a slightly different position in the cavernous sinus, and was subsequently inflated and detached without complication. Transient hemiparesis lasting less than 24 hours occurred in the first patient treated (case 1), and resolved completely with heparin. There was no permanent neurological deficit in any patients treated. Seven patients experienced severe pain during infla- tion of the balloon in the cavernous sinus, requiring administration of intravenous pethidine. This pain may be related to pressure or displace- ment of cranial nerves, dura mater or other structures during balloon infla- tion. There were no permanent cranial nerve palsies related to the presence of balloons in the cavernous sinus. There was also no clinical evidence of ORIGINAL ARTICLE 9 SA JOURNAL OF RADIOLOGY • February 2005 Radiology 2/24/05 4:50 PM Page 9 nerve compression where more than 1 balloon was placed in the cav- ernous sinus. Two patients became restless during balloon placement and required deep sedation by the anaesthesiologist. All patients were followed up clin- ically with neurological and ophthal- 10 SA JOURNAL OF RADIOLOGY • February 2005 ORIGINAL ARTICLE Table III. Summary of 34 patients with carotid-cavernous fistulae (in chronological order) Case Age Approach Fistula ICA Treatment/ No No (yrs) Sex Cause Arterial Venous occluded Patent of balloons 1 22 F Gunshot Y Yes No 1 2 30 M Gunshot Y Yes No 1 3 34 M MVA Y Yes Yes 3 4 55 F Ruptured Yes Yes Thrombosed aneurysm Neither approach 5 26 F MVA Y Yes No Surgery 6 55 F MVA Y Yes No Surgery 7 35 F MVA Y Yes Yes 1 8 48 F MVA Y Yes Yes 1 9 36 M MVA Y Yes Yes 1 10 29 M MVA Y Yes No 1 11 49 F MVA Y Yes No 1 12 50 F MVA Y Yes Yes 1 13 30 M Assault Y Yes Yes 1 14 31 M Assault Y Yes Yes 1 15 45 M MVA Y Yes No 1 16 54 F MVA Y Yes No 1 17 46 M MVA Y Yes Yes 1 18 52 F Assault Y Yes Yes 1 19 37 F Stab wound Y Yes No 3 20 25 M Stab wound Y Yes No 3 21 35 M Assault Y Yes Yes 1 22 41 F Assault Y Yes No 1 23 40 M Gunshot Y Yes No 1 24 35 M Stab wound Y Yes No 1 25 29 F Assault Y Yes Yes 1 26 38 M Stab wound Y Yes Yes 1 27 41 F Stab wound Y Yes No 1 28 39 M Gunshot Y Yes No 1 29 40 M Gunshot Y No No 1 30 30 M MVA Y Yes Yes 1 31 50 M MVA Y Yes Yes 1 32 49 F MVA Y Yes Yes 1 33 42 F MVA Y Yes Yes 1 34 39 F MVA Y Yes No 1 MVA = motor vehicle accident; ICA = internal carotid artery. Table IV. Patients requiring more than one balloon to occlude the fistula Case no. Balloon type No. of balloons used 3 GVB 16 3 19 GVB 9 3 20 GVB 9 3 Radiology 2/24/05 4:50 PM Page 10 mological examinations performed on an outpatient basis. An average follow-up of 5 months was used to ensure that the fistula remained clini- cally closed, although poor patient compliance limited this duration. The outcomes of all 34 patients are summarised in Table III. Technical problems that occurred during embolisation are summarised in Table V. Discussion CCF has evolved from being an untreatable condition to a readily curable one over the past 35 years. The early treatment by proximal occlusion or trapping of the ICA has fallen into disfavour because of the high associated incidence of compli- cations and incomplete closure of the fistula.6,10,20 Serbinenko11 and Debrun et al. 13,15,16,20 pioneered techniques of closing these fistulae with detachable latex or silicone balloons while pre- serving the ICA in the majority of cases. Large series have proved the effectiveness of endovascular balloon embolisation,3,4,12,15,21,22 which is now the treatment of choice for this entity. The overall results of the 33 patients treated by the endovascular approach in this series show that the fistula was successfully occluded in 30 cases (91%), preserving the carotid artery in 16 cases (53%). These results compare reasonably with those of other centres (Table VI). The largest series of 482 patients is from China23 where 100% success and 84% ICA preservation were achieved. In 14 of the successfully embolised cases where the ICA could not be preserved in the present series, 9 fis- tulae were the result of stab wounds or gunshots. This could suggest that gunshots and stab wounds may cause larger tears in the carotid artery. In 1 case (case 20), an antelope’s horn caused an orbital stab wound. Large tears in the carotid artery could also be responsible for herniation of the balloon from the cavernous sinus into the ICA, resulting in a parent vessel occlusion (Fig. 4). The presence of cross-flow via the anterior communicating artery is vital to determine with a cross-com- pression angiogram. It is also critical when ICA occlusion is considered to examine the patient neurologically for at least 20 minutes while the bal- ORIGINAL ARTICLE 11 SA JOURNAL OF RADIOLOGY • February 2005 Table V. Technical problems during embolisation (grouped by type of problem) Case No. Problems Outcome 5 Balloon accidentally detached in the ICA Surgery — trapping procedure 6 Attempt at embolisation failed due to the tortuous ICA Surgery — trapping procedure 29 Facial and ophthalmic veins approach failed Lost to follow-up 30 Spasm of the ICA during placement of 9-French guiding catheter Second attempt uncomplicated 32 Two balloons ruptured during inflation in the cavernous sinus Third balloon succeeded 12 9- French guiding catheter kinked at the origin of the left CCA More rigid 10-French catheter (Cook) was used 18 9-French guiding catheter kinked at the origin of the left CCA More rigid 10-French catheter (Cook) was used 31 9-French guiding catheter kinked at the origin of the left CCA More rigid 10-French catheter (Cook) was used 32 9-French guiding catheter kinked at the origin of the left CCA More rigid 10-French catheter (Cook) was used 21 Severe pain during inflation of the balloon in the cavernous sinus Deep sedation 25 Severe pain during inflation of the balloon in the cavernous sinus Deep sedation 3 Partially inflated balloon accidentally detached in the cavernous Two balloons required to occlude the fistula, sinus ICA preserved 28 Balloon migrated deeper into the cavernous sinus shortly after Second balloon used to close the fistula detachment 29 Facial and ophthalmic venous approaches failed ICA = internal carotid artery; CCA = common carotid artery. Fig. 4a. Lateral internal carotid angiogram showing fistula and dilated inferior petrosal sinus (arrow). The origin of the fistula was most likely from the posterior aspect of the cavernous part of the carotid artery. Transarterial placement of the bal- loon was unsuccessful despite multiple attempts. Radiology 2/24/05 4:50 PM Page 11 loon is inflated. Endovascular embolisation of the CCF should therefore be performed under local anaesthesia, allowing continous neu- rological monitoring of the patients. However, angiographic and clinical (neurological) assessment prior to permanent ICA occlusion is far from ideal and does not prevent delayed ischaemic complications. Carotid artery occlusion in patients without CCFs is associated with a 5 - 22% rate of neurological ischaemic com- plications, despite a clinically tolerat- ed test occlusion.24,25 In an effort to reduce the morbidity of carotid artery occlusion, several quantitative blood-flow imaging techniques are available, including transcranial Doppler sonography, Tc-99m hexa- methyl-propylene-amine oxime (HMPAO) SPECT perfusion imag- ing, xenon CT perfusion, perfusion CT, perfusion MRI, diffusion-weight- ed MRI and contrast-enhanced fluid- attenuated inversion recovery (FLAIR) MRI imaging.24,25 The sensi- tivity of the balloon test occlusion can be further increased by perform- ing hypotensive test occlusion.24 Practically, the initial test is often cerebral angiography performed dur- ing cross-compression, which aids in determining the presence of collateral circulation via the circle of Willis. No neurological deficit was observed in all 14 patients where the ICA had to be sacrificed in this series. Overall, there was no permanent neurological deficit in any patient treated. The patient with a CCF may be at less risk from carotid occlusion because of the haemodynamics involved. Of the 34 cases of CCF, 31 fistulae were less than 4 months old while the remaining 3 were over 6 months old. There were no complications 12 SA JOURNAL OF RADIOLOGY • February 2005 ORIGINAL ARTICLE Fig. 4b. Lateral internal carotid angiogram follow- ing placement of single balloon (arrow) via the infe- rior petrosal sinus, closing the fistula with preser- vation of the internal carotid artery. Table VI. CCF embolisation — comparative results from different centres Autbor No. of cases Results Balloon type Complications (N) Debrun et al.13 17 100% -CCF occluded (1978) 70% -ICA preserved Latex III n. palsy (1) Debrun G et al.16 54 98% - CCF occluded III n. palsy (1) (1981) 59% -ICA preserved Latex Middle cerebral artery infarcts (2) Norman D, 10 90% - CCF occluded Newton T29 40%- ICA preserved Silicone None (1983) Larsen D, 206 92% - CCF occluded III n. palsy (1) Higashida R, 88% - ICA preserved Silicone Ischaemic stroke (5) Halbach V (1989) Joseph S, 25 80% - CCF occluded Rao V 64% - ICA preserved Silicone Death (1) (1993) Lewis A et al.3 100 86% - CCF occluded Latex Death (1) (1995) 75% - ICA preserved Silicone Permanent neurological complications (4) Wu Z et al.23 482 100% - CCF occluded Latex (2000) 84% - ICA preserved Silicone Not stated Coils Radiology 2/24/05 4:50 PM Page 12 observed during the treatment of those of over 6 months duration, despite the potential risks involved in treating longstanding fistulae. Established fistulae may impair the brain’s ability to autoregulate its own perfusion. Abrupt closure of these longstanding fistulae can therefore sometimes result in overperfusion, termed ‘normal perfusion pressure breakthrough’,26 first described by Spetzler et al.27 This may also occur during occlusion of cerebral arterio- venous malformations. The inci- dence is small for CCFs (1.2%), but higher for chronic vertebral fistulae (15%).26 All 33 fistulae were treated elec- tively. There was no need for any urgent intervention. The usual indi- cations for urgent treatment of CCFs are: (i) haemorrhage or epistaxis; (ii) cerebral ischaemia due to vascular steal by the fistula from the other cerebral arteries; (iii) marked aneurysmal dilatation of the cav- ernous sinus, which may result in fatal subarachnoid hemorrhage; (iv) prominent, abnormal venous drainage into cortical veins, which could produce venous hypertension and parenchymal hemorrhage; and (v) rapidly progressive visual deterio- ration, potentially leading to blind- ness.2,4 Technical aspects In all of these cases, latex Goldvalve balloons were used. The most frequently used balloon was the GVB 9 balloon of 1.3 ml volume, measuring 19 x 11 mm when fully inflated. Both silicone (Target-Boston Scientific, Fremont, CA) and latex balloons are commonly used for endovascular embolisation and their safety as biomedical materials has been confirmed.28-30 The relative advantages and disadvantages of latex versus silicone balloons are not clear- ly defined.29 Latex Goldvalve balloons are far less expensive than silicone balloons. Latex balloons have the advantage of greater distensibility and can therefore be inflated to larger size. Often a single balloon is suffi- cient to close the fistula. Latex bal- loons have proved to be more throm- bogenic than silicone balloons, and endothelialisation and thrombus for- mation occur more rapidly with latex than with silicone balloons.22,26 This is thought to be related to the surface structure of the latex balloons26 and local tissue reaction around the latex balloon.26,29 When the surface of latex and silicone balloons is examined under electron microscopy, the sili- cone balloon has a smooth, even sur- face with a homogeneous structure, whereas the latex balloon is rough and porous with numerous large deep craters. This irregular surface may cause turbulent flow and throm- bosis, entrapping blood cells and platelets.28 Latex balloons also induce a mild to moderate degree of local tissue reaction. This could be advan- tageous as it may promote further thrombosis.29 There is some concern regarding latex allergy, following several report- ed fatalities due to allergic reactions to rectal latex balloons inserted dur- ing barium enemas.28 However, there is no clinical evidence that latex bal- loons in the cerebral vasculature can cause these allergic reactions.22 The balloon should remain inflat- ed for approximately 1 week to guar- antee its fibrous attachment to the vascular wall and permanent occlu- sion of the fistula.22 Presumably, the vascular obstruction and irritation caused by the balloon initiates the sealing process. The haemostatic plug that forms should develop into an organised thrombus. As this clot organises further over several days, it is transformed into a scar attached to the vessel wall. This ultimately keeps the balloon in place. Ideally the Debrun latex balloon remains inflat- ed for 3 - 5 weeks. Silicon detachable balloons with integrated valves remain inflated for months. 22,28,29,31 As yet, there are no long-term follow-up studies of latex Goldvalve balloons. When the balloon deflates rapidly, venous pouches or false aneurysms frequently form. These can grow silently, reaching sizes as large as 4 - 5 cm without producing any oculomo- tor nerve palsy or other problems.16 Anatomical factors play a domi- nant role in balloon delivery. In 1 patient (case 6), the procedure had to be abandoned due to a very tortuous carotid artery, and in another patient (case 5) the partially inflated balloon was accidentally detached during manipulation within a tortuous carotid artery. Use of large balloons requires large 9 or 10- French guiding catheters to be introduced into the ICA. These catheters can cause dis- section or spasm of the vessel. They may also kink as they bend to enter the common carotid or brachio- cephalic artery. Transvenous embolisation via the inferior petrosal sinus or superior ophthalmic vein remain an alterna- tive but potentially difficult route (Fig. 4). The venous drainage from the cavernous sinus is normally vari- able and can be diverted by the pres- ence of a fistula. Anatomically, the cavernous sinus is usually drained by the contralateral cavernous sinus, the superior ophthalmic vein, the ORIGINAL ARTICLE 13 SA JOURNAL OF RADIOLOGY • February 2005 Radiology 2/24/05 4:50 PM Page 13 sphenoparietal sinus, the pterygoid venous plexus, and the superior and inferior petrosal sinuses (Fig. 5).32 The lack of inferior petrosal sinus visualisation during angiography does not necessarily indicate its occlusion or absence. Direct catheter- isation of the inferior petrosal sinus, whether angiographically demon- strated or not, may be technically dif- ficult due to the small calibre of the often tortuous vessel, and carries a risk of perforation with subsequent subarachnoid haemorrhage.3,17 It is extremely difficult to navigate a catheter with a balloon into or through the partitions of the cav- ernous sinus to the fistula site. Another pitfall of either approach is converting the cavernous sinus into an aneurysm by blocking all venous drainage without occluding the fistu- la. Occluding posterior venous drainage can result in the diversion of flow into the superior ophthalmic vein and an abrupt loss of vision. Occluding the anterior drainage may increase cortical or petrosal venous drainage and could cause cerebral or brainstem venous hypertension or haemorrhage.3,17 Electrolytically detachable coils such as Guglielmi detachable coils (GDCs) and pushable, fibre-coated micro-coils can be used in the pres- ence of difficult anatomy to occlude the CCF from the arterial side. They can also be employed from the venous side to navigate into and through the septated cavernous sinus.33,34 GDC coils are especially useful for CCFs caused by ruptured intracavernous aneurysms or where use of balloons can be very danger- ous, such as in patients with Ehlers - Danlos syndrome.8,19,34,35 Coils can also be helpful when balloons cannot enter the fistula, as sometimes occurs after placement of a number of bal- loons narrows the entry into the fis- tulae. Other detachable coils and endovascular stents are promising new devices that may increase the rate of fistula occlusion and ICA preservation. In the meantime, transarterial detachable balloons remain the treat- ment of choice for direct CCFs. 2,3,17,19,30,32 Conclusion From this analysis of the 34 cases of CCF treated over 4 years, the fol- lowing conclusions can be drawn: (i) a high percentage (91%) of direct CCFs were successfully occluded with detachable balloons; (ii) in 53% of cases the ICA was preserved; (iii) the latex Goldvalve balloons used in all cases proved to be very effective; and (iv) there were no permanent neurological complications in any of the patients treated. References 1. Halbach V, Hieshima G, Higashida R, Reicher M. Carotid cavernous fistula — indications for urgent treatment. Am J Neuroradiol 1987; 8: 627-633. 2. Phatouros C, Meyers P, Dowd C, Higashida R. Carotid artery cavernous fistulas. Neuroendo- vascular Surgery 2000; 11(1): 67-84. 3. Lewis A, Tomsik T, Tew J. Management of 100 consecutive direct carotid cavernous fistulae. Results of treatment with detachable balloons. Neurosurgery 1995; 36: 239-244. 4. Barrow DL, Spector H, Braun JF. Classification and treatment of spontaneous carotid cav- ernous fistulae. J Neurosurg 1985; 65: 248-258. 5. Debrun GM, Vinuela F, Fox A. Indications for treatment and classification of 132 carotid cav- ernous fistulas. Neurosurgery 1988; 22: 285-289. 6. Parkinson D. Carotid cavernous fistula — direct repair with preservation of carotid artery. J Neurosurg 1973; 38: 99-105. 7. Prolo D, Hanberry JW. Intraluminal occlusion of a carotid cavernous fistula with a balloon catheter: technical note. J Neurosurg 1971; 35: 237-242. 8. Siniluto T, Seppanen S. Transarterial emboliza- tion of direct carotid cavernous fistula with GDC coils. Am J Neuroradiol 1997; 18: 219-256. 9. Debrun GM, Lecour P, Caron J. Experimental approach to the treatment of carotid cavernous fistulae with inflatable and isolated balloon. Neuroradiology 1975; 9: 9-12. 10. Mullan S. Treatment of carotid cavernous fistu- la by cavernous sinus occlusion. J Neurosurg 1979; 50: 131-144. 11. Serbinenko FA. Balloon catheter and occlusion of major cerebral vessels. J Neurosurg 1974; 41: 125-143. 12. Teitelbaum G, Larsen D, Zelman V, Lysachev A, Likhterman L. A tribute to Dr Fedor A Serbinenko, founder of endovascular neuro- surgery. Neurosurgery 2000; 46: 426-470. 13. Debrun GM, Lacour P, Fox A. Detachable bal- loon and calibrated-leak balloon catheter in treatment of cavernous lesions. J Neurosurg 14 SA JOURNAL OF RADIOLOGY • February 2005 ORIGINAL ARTICLE Fig. 5a. Lateral internal carotid angiogram showing fistula with venous drainage into the superior oph- thalmic vein (arrow) and cortical veins (double arrows). Fig. 5b. Lateral internal carotid angiogram follow- ing embolisation, showing fistula occluded and carotid artery preserved. Radiology 2/24/05 4:50 PM Page 14 ORIGINAL ARTICLE 15 SA JOURNAL OF RADIOLOGY • February 2005 1978; 49: 635-549. 14. Hieshima G, Verity S. A detachable balloon for therapeutic transcatheter occlusions. Radiology 1981; 138: 227-228. 15. Debrun GM. Teatment of traumatic carotid cavernous fistulae using detachable balloon catheters. Am J Neuroradiol 1983; 4: 355-366. 16. Debrun GM, Lacour P, Vinuela F, Fox A. Treatment of 54 carotid cavernous fistulae. J Neurosurg 1981; 55: 678-692. 17. Halbach V, Higashida R, Hieshima G, Hardin C, Yang P. Transvenous embolization of direct carotid cavernous fistula. Am J Neuroradiol 1988; 9: 741-747. 18. Higashida R, Halbach V, Tsai F. Interventional neurovascular treatment of traumatic carotid and vertebral lesions. Am J Roentgenol 1989; 153: 577-582. 19. Hanneken A, Neil A, Miller R, Debrun G, Haring J, Nauta W. Treatment of CCF using a detachable balloon catheter through the superi- or ophthalmic vein. Acta Ophtalmol 1989; 107: 87-92. 20. Debrun GM, Lacour P, Fox. A. Traumatic carotid cavernous fistulae — clinical presenta- tion, diagnosis. J Neurosurg 1987; 3: 242-247. 21. Berenstein A, Kricheff J, Rausohoff J. Carotid cavernous fistulae — intraarterial treatment. Am J Neuroradiol 1980; 1: 449-457. 22. Lewis A, Tomsik T. Long term results in direct carotid cavernous fistulae after treatment with detachable balloons. J Neurosurg. 1996; 84: 400- 404. 23. Wu Z, Zhang Y, Wang C, Yang X, Li Y. Treatment of traumatic carotid-cavernous fistula. Interventional Neuroradiology 2000; 6: 277-289. 24. Scott C, Arvind A, Lee R. Balloon test occlusion of the internal carotid artery with hypotensive challenge. Am J Neuroradiol 1995; 16: 1453- 1458. 25. Michel E, Liu H, Remley K. Perfusion MR neu- roimaging in patient undergoing balloon test occlusion of the internal carotid artery. Am J Neuroradiol 2001; 22: 1590-1595. 26. Halbach V, Higashida R, Hieshima G. Normal perfusion pressure breakthrough occurring during treatment of carotid and vertebral fistu- lae. Am J Neuroradiol 1987; 8: 751-756. 27. Spetzler RF, Wilson C, Wenstein P. Normal per- fusion pressure breakthrough theory. Clin Neurosurg 1978; 25: 651-672. 28. Miyachi S, Negoro M, Handa T, Terashima K, Keino H, Sugita K. Histopathological study of balloon embolization; silicone versus latex. Neurosurgery 1992; 30: 483-489. 29. Norman D, Newton T. Carotid cavernous fistu- la — closure with detachable silicone balloons. Radiology 1983; 149: 149-157. 30. Graeb D, Robertson D, Lapointe J, Nugent A. Avoiding intraarterial balloon detachment in the treatment of post traumatic carotid cav- ernous fistulae with detachable balloons. Am J Neuroradiol 1985; 6: 602-605. 31. Thomsick T. Osmotic effect upon long term inflation of latex detachable balloons. Neurosurgery 1985; 17: 952-954. 32. Gebarski S, Gebarski KS. Inferior petrosal sinus. Imaging, anatomic correlations. Radiology 1995; 194: 239-247. 33. Miller N, Monsein L, Debrun G, Tamargo R, Haring J, Nauta M. Treatment of carotid cav- ernous fistula using a superior ophthalmic vein approach. J Neurosurg 1995; 83: 838-842. 34. Kanner A, Maimon S, Rappaport Z. Treatment of spontaneous carotid-cavernous fistula with Ehlers-Danlos syndrome by transvenous occlu- sion with Guglielmi detachable coils. J Neurosurg 2000; 93: 689-692. 35. Hollister D. Heritable disorders of connective tissue: Ehlers-Danlos syndrome. Pediatr Clin North Am. 1978; 25: 575-590. Pacific Health Limited is seeking to appoint a General Radiologist and/ora Locum to work up to 40 hours per week. The positions will be based at Tauranga Hospital (321 beds), which serves a population base of 130,000 in the Western Bay of Plenty, New Zealand. The Bay of Plenty enjoys a sunny climate which is ideal for growing avocados, grapes, kiwifruit, citrus and other subtropical fruits for which the region is famous. The fruit along with timber, paper and dairy products, is exported through the Port of Tauranga, the largest export port in New Zealand and the commercial centre of the Northern Bay of Plenty. The harbour and South Pacific ocean that give Tauranga so much of its natural beauty also offers some exciting deep sea game fishing and is an important offshore commercial fishing base. The Radiology Department comprises four general rooms, an angiographic and special procedures room, a GE Spiral CT (Prospeed) soon to be upgraded to a 64 Multi-slice CT Scanner, three colour doppler ultrasound machines and a fluoroscopy room. A private MRI facility is operational on- site. The appointee would join 9 other Radiologists, 2 Registrars, 4 Sonographers, 5 Nurses, 17 Radiographers and other support staff who offer a 24-hour acute service. Applicants must be eligible for registration as a Specialist Diagnostic Radiologist with the Medical Council of New Zealand. Closing date: Open We need a hand....in NEW ZEALAND Radiologists Radiologist Position No 0409-41-SAR Radiology Department , Tauranga 1.0 FTE (80 hours per fortnight) Locum Radiologist Position No 0407-21-SAR Radiology Department, Tauranga 1.0 FTE (80 hours per fortnight) For an application pack and job description visit www.bopdhb.govt.nz or contact the Recruitment Centre BOP DHB Tel: +64 7 579 8036 or +64 7 579 8361. Enquiries can be emailed to jillian.wright@bopdhb.govt.nz or roy.buchanan@bopdhb.govt.nz Radiology 2/24/05 4:50 PM Page 15