Carotid Cavernous Fistula

Carotid cavernous fistulae (CCFs) are arteriovenous shunts involving the cavernous sinus. CCFs are defined as direct or indirect. Direct CCFs are treated by deconstructive or reconstructive techniques depending on whether the affected internal carotid artery is required to perfuse the ipsilateral cerebral hemisphere, as determined by a balloon test occlusion. Indirect CCFs, or dural fistulae of the cavernous sinus wall, are most often treated with transvenous embolization. Stereotactic radiosurgery is reserved for cases of indirect CCFs that are not completely obliterated by embolization. Overall, cure rates are high with relatively low complication rates.

Clinical Presentation of Carotid-Cavernous Fistula and Outcomes of Endovascular Balloon Embolization

Objectives

To describe the clinical presentation of carotico-cavernous fistula (CCF) and outcomes of endovascular balloon embolization in a tertiary care center in a developing country.

Materials and Methods

This retrospective interventional case series included 18 patients who underwent endovascular balloon embolization from 2019 to 2022 at Lahore General Hospital in Lahore, Pakistan. The analyzed data consisted of age, gender, cause and type of CCF, clinical presentation, diagnostic technique used, intervention, and the results of two-month follow-up. Patients with incomplete records and coil embolization were excluded. Digital subtraction angiography was done in all cases followed by endo-arterial balloon embolization. Procedures were carried out under general anesthesia via femoral artery approach. A single balloon was sufficient to close the fistula in all cases.

Results

There were 18 patients who met the inclusion criteria. Sixteen patients had direct CCF, and the mean age of the patients was 27.2±12.6 years. The commonest cause of CCF was trauma, and the mean time of presentation after trauma was 7.89±7.19 months. The male-to-female ratio was 8:1. Preoperative visual acuity was worse than 6/60 in 8 patients, between 6/60 and 6/18 in 7 patients, and better than 6/18 in 3 patients. The mean intraocular pressure was 16.06±3.37 mmHg preoperatively and 14.83±3.49 mmHg postoperatively (p=0.005). Endovascular embolization was successful in 15 patients (83.3%). One patient developed epidural hematoma as a complication of the procedure, which was drained later. There was no mortality related with the procedure.

Conclusion

Balloon embolization via the femoral artery is an efficient technique in direct as well as indirect CCF. It is safe and simple with very good results if performed in a timely manner.

Natural course of partially embolized carotid-cavernous fistulas

BACKGROUND AND PURPOSE

To present the first study analyzing the clinical and radiological course of carotid-cavernous fistulas (CCFs) following incomplete embolization. The study compares magnetic resonance angiography (MRA) to plain angiography (digital subtraction angiography [DSA]) and investigates the long-term ophthalmological impact of residual fistula.

METHODS

Fistulas classified as partially embolized after the last endovascular treatment were prospectively followed with DSA, MRA, and ophthalmological examination. Both direct and indirect CCFs were included.

RESULTS

Twenty-one CCFs were included in the study. Nine (43%) fistulas were direct and 12 (57%) were indirect. A favorable clinical outcome of modified Rankin scale ≤2 was recorded in 19 (90%) patients at the last follow-up. Postinterventional ophthalmologic examinations in 16 patients revealed no negative effects of residual fistulas; five remaining patients refused to undergo further examination. Spontaneous thrombosis and complete occlusion of the CCF were demonstrated in 90% of patients, with a mean time to occlusion of 5.7 ± 4.7 months. Fourteen (66%) patients completed the full imaging follow-up (MRA and DSA). In 21% of these cases, discrepancy between the two imaging modalities was observed-MRA failed to detect persistent fistulas identified by DSA.

CONCLUSIONS

The goal of CCF treatment is safe and complete embolization. However, if adequate flow reduction is achieved, both direct and indirect CCFs tend to spontaneously thrombose. Residual flow does not result in ophthalmological deterioration until the fistula is completely closed. MRA may not be sufficiently sensitive to detect residues of fistulas including cortical venous drainage. Therefore, complete CCF closure should be confirmed through DSA.

Extraocular muscle enlargement and proptosis in carotid cavernous fistulas

PURPOSE

To evaluate the prevalence and pattern of extraocular muscle enlargement and proptosis in patients with carotid cavernous fistulas (CCF).

METHODS

We conducted a retrospective study on patients with digital subtraction angiography (DSA) confirmed CCFs with neuroimaging (computed tomography or magnetic resonance imaging) performed prior to the DSA. The maximum extraocular muscle diameters were recorded. Extraocular muscles were considered enlarged if they were greater than two standard deviations above the normal muscle diameters. Proptosis was defined as the distance between the interzygomatic line to the anterior globe of ≥2 mm compared to the contralateral orbit or ≥21 mm.

RESULTS

Forty orbits from 20 patients were included. The mean age of participants was 65 ± 15 years and 13 (65%) were female. Thirteen (65%) fistulas were indirect and seven (35%) were direct. There was enlargement of at least one muscle in 11 (27.5%) orbits, and this was not correlated with the type of fistula (direct/indirect). The inferior rectus was most commonly enlarged in seven orbits (17.5%), followed by the medial rectus in five orbits (12.5%). Proptosis was found in 17 (43%) orbits and was more common ipsilateral to the fistula (58% ipsilateral group vs 19% contralateral group, p < .01).

CONCLUSION

Extraocular muscle enlargement was observed in over one-fourth of CCFs. When enlarged, the inferior and medial rectus muscles are most commonly involved. These findings may help clinicians and radiologists when evaluating the CT or MRI scans of patients with suspected CCFs.

Bilateral Low-Flow Type-D Dural Carotid-Cavernous Fistula: Diagnosis and Treatment with 3D Time-of-Flight Magnetic Resonance Angiography

BACKGROUND Carotid-cavernous fistula (CCF) is a rare, atypical vascular shunt between the carotid arterial system and the venous channels of the cavernous sinus, classified according to the shunt's anatomy, by etiology (resulting from trauma or occurring spontaneously), or by hemodynamic characteristics (such as low- or high-flow fistulas). CASE REPORT A 62-year-old female patient with poorly controlled arterial hypertension presented with bilateral periorbital edema, conjunctival chemosis, ophthalmoplegia, diplopia, and diminished visual acuity. On magnetic resonance angiography (MRA), abnormal arterial flow along the cavernous sinuses was noted, suggestive of bilateral CCF. The diagnosis of indirect dural low-flow CCF (Barrow Type D) was later confirmed by digital subtraction angiography, with feeding arteries from intracavernous internal carotid artery branches, and meningeal branches of the external carotid artery, draining bilaterally to ophthalmic veins, the intracavernous sinus, and the inferior petrosal sinus. The patient was successfully treated with endovascular embolization. At 7-month follow-up, no residual arteriovenous shunting was detected. This case highlights the importance of non-invasive radiological methods for CCF, and presents rarely published radiological findings of bilateral Type-D dural CCFs on 3-dimensional time-of-flight MRA with post-treatment MRA follow-up. CONCLUSIONS Regardless of the patient's history of possible trauma, a patient presenting with bilateral periorbital edema, conjunctival chemosis, ophthalmoplegia, diplopia, and diminished visual acuity should have a spontaneous bilateral CCF investigated to prevent delayed treatment. Experienced neuroradiologists are needed to accurately detect indirect CCF, since this condition often does not demonstrate classic symptoms.

[Carotid-cavernous fistulas]

BACKGROUND

Carotid cavernous fistulas (CCFs) are rare but clinically significant vascular anomalies characterized by abnormal connections between the cavernous sinus and arteries. This overview presents a comprehensive analysis of anatomy, classification, clinical presentation, diagnosis, imaging, and therapy of CCFs. The cavernous sinus, a central venous structure in the brain, is of critical importance for understanding CCFs due to its proximity to key structures such as the internal carotid artery and cranial nerves.

CLASSIFICATION

CCFs are classified into direct and dural types, with direct fistulas typically being high-flow and dural fistulas being low-flow. The symptomatology varies greatly and can range from noises in the head, diplopia, red eye, tearing, to blurred vision and headaches. The diagnostic assessment requires a combination of detailed medical history, neurological and ophthalmological examination, and the use of imaging techniques.

METHODS

In imaging, computed tomography (CT) and magnetic resonance imaging (MRI) are crucial for depicting the anatomical structures and blood vessels, while digital subtraction angiography (DSA) is considered the gold standard for accurate representation of the fistula. The treatment of CCFs is complex and depends on the type of fistula, location, and clinical condition of the patient.

CONCLUSION

This overview emphasizes the importance of precise diagnosis and individualized therapy to achieve optimal results and avoid complications. Ongoing developments in medical imaging and treatment techniques will continuously improve the treatment outcomes of patients with CCFs.

Off-label use of large diameter Concerto fibered coils through a 0.017 inch microcatheter for transvenous embolization of indirect carotid-cavernous fistulas: two case reports

BACKGROUND

A carotid-cavernous fistula is an abnormal communication between the arteries and veins within the cavernous sinus. While conservative management may be prudent in low risk cases, many patients require intervention and endovascular embolization has evolved as the preferred method of treatment. Embolization can be performed via either the transarterial or transvenous approach. One major challenge of the transvenous approach is the complex and variable compartmentation of the cavernous sinus, which often requires the use of low profile microcatheters to navigate and reach the fistulous point. Fibered coils are also preferred when performing transvenous embolization of carotid-cavernous fistula, as they are of higher thrombogenicity and allow for faster occlusion of the fistula. However, most low profile (0.017-inch) microcatheters are not able to deploy fibered coils based on the manufacturer's instructions.

CASE PRESENTATION

We present two successful cases of off-label use of Medtronic Concerto fibered coils via a 0.017-inch microcatheter during transvenous embolization of carotid-cavernous fistula in a 60-year-old and an 80-year-old Chinese female, respectively.

CONCLUSION

Our case series highlight the possibility of deploying large diameter (up to 10 mm) Concerto fibered coils through a low profile (0.017-inch) microcatheter in an off-label manner for transvenous embolization of indirect carotid-cavernous fistula.

Transorbital embolization of cavernous sinus dural arterio-venous malformations with surgical exposure and catheterization of the superior ophthalmic vein

PURPOSE

Cavernous sinus dural arterio-venous malformations (dAVF) represent a pathologic connection between branches of the internal and/or external carotid artery and the cavernous sinus. Standard endovascular approaches for dAVF treatment are transvenous embolization through the inferior petrosal sinus or the facial vein and transarterial embolization. These approaches are not always successful or feasible, and alternative techniques are required. Here, we present a case series of a minimally invasive transorbital approach with surgical exposure and catheterization of the superior ophthalmic vein for transvenous fistula coiling.

METHODS

14 patients with dAVFs (Barrow Type B to D) that were treated at a tertiary care medical center over a period of 13 years were included in the study. Patients with persisting dAVF associated symptoms were selected for this approach when conventional endovascular interventions were not successful or not feasible. The surgical procedure was performed under general anaesthesia.

RESULTS

A successful transorbital approach was performed in all 14 cases. In 12 of 14 patients a catheter assisted successful embolization of the fistula was performed using platinum coils with no relevant residual fistula flow. In two cases, a spontaneous thrombosis of the fistula during the surgical procedure required no further embolization. No postoperative therapy-associated complications were observed.

CONCLUSION

The described approach is an effective method to embolize dAVFs in selected cases when catheter assisted transvenous and/or transarterial embolization is not successful or not feasible. In this case series we demonstrate an excellent success rate with no therapy-associated major complications.

Patch Technique for Primary Treatment of Type A Carotid Cavernous Fistula: A Case Series and Technical Notes

BACKGROUND

The utilization of flow diverters (FDs) in the treatment of high-flow Type A carotid cavernous fistulas (CCFs) has been described before mainly as an adjunct to the traditional endovascular techniques and rarely as a stand-alone treatment. In this study, we retrospectively evaluated our experience with FDs as the solo nonadjunctive treatment of Type A CCF with severe cortical venous reflux (CVR).

METHODS

A retrospective review was performed of patients with Type A CCFs who were treated using FDs' patch technique (PT). Patients' demographics, clinical data, and preoperative and postoperative ocular examination were recorded. The procedure technique, pipeline embolization device (PED) diameters, and immediate and late procedure outcomes were described.

RESULTS

Three patients were included in this case series. All patients had history of trauma and presented with decreased visual acuity, cranial nerve II deficit, limited extraocular muscles' movement, and increased intraocular pressure (IOP). Diagnostic angiography was performed, which confirmed high-flow Type A CCF. Endovascular treatment was performed through distal radial access in 2 patients and femoral access in 1 patient by deploying 4 sequentially enlarging PEDs with immediate resolution of the ocular symptoms. Follow-up angiography confirmed complete resolution of CCF in 2 patients. One patient was lost to follow-up; however, angiogram at 4 months demonstrated residual small CCF with significant improvement from postprocedure angiogram.

CONCLUSIONS

The patch technique using sequentially enlarging FDs is a reasonable alternative solo technique for the treatment of direct CCF symptoms and results in immediate resolution of CVR while preserving the cavernous sinus anatomy.

Direct puncture of the superior ophthalmic vein for carotid cavernous fistulas: a 21-year experience

BACKGROUND

Direct puncture of the superior ophthalmic vein (SOV) is an alternative approach to traversing the inferior petrosal sinus for embolization of carotid cavernous fistulas (CCFs).

OBJECTIVE

To analyze direct SOV puncture for the treatment of CCFs and review the literature.

METHODS

All patients at a single center, treated for a CCF with direct SOV cannulation between January 1, 2000, and December 31, 2020, were retrospectively analyzed. An additional review of the literature for all case series for direct puncture of the SOV for treatment of CCF was performed.

RESULTS

During the 21-year study period, direct cannulation of the SOV for treatment of a CCF was attempted for 19 patients, with the procedure aborted for one patient because of an inability to navigate the wire into the distal aspect of the cavernous sinus. In 18 patients with direct SOV CCF treatment, 1 experienced a minor complication with an asymptomatic postoperative hemorrhage. Angiographic cure and improvement of symptoms were achieved in 17 patients with a mean (SD) follow-up of 6 (5.2) months. In the review of the literature, an additional 45 patients were reported to have direct cannulation of the SOV for CCF treatment, with angiographic cure in 43 (96%) and decreased objective visual acuity in 1 (2%).

CONCLUSION

Direct SOV cannulation to treat CCFs is safe and effective. Although it is typically used after other endovascular approaches have failed, SOV access for CCF treatment may be warranted as a first-line treatment for select patients.

Endoscopic endonasal transsphenoidal Onyx embolization of a paracavernous dural arteriovenous fistula

Paracavernous dural arteriovenous fistulas (pdAVFs) are extremely rare and can mimic carotid cavernous fistulas (CCFs) in both clinical presentation and imaging characteristics. Access to the venous pouch often presents the greatest challenge in the treatment of pdAVFs. Here we present a novel access technique utilizing an endoscopic endonasal transsphenoidal approach, where we directly puncture the venous pouch under both stereotactic guidance and endoscopic visualization, thereby completely embolizing a pdAVF with no alternate access (video 1). neurintsurg;15/10/1055/V1F1V1Video 1Technical video demonstrates the complete embolization of a pdAVF using an endoscopic endonasal transsphenoidal approach.

Intermittent Manual Carotid Compression as a Treatment Option for Indirect Low Flow Carotid Cavernous Fistula

PURPOSE

To evaluate the efficacy of intermittent manual carotid compression (IMCC) in the management of low-flow carotid cavernous fistulae (CCF).

MATERIALS AND METHODS

Patients diagnosed with low-flow CCF and treated with IMCC over a period of 13 years were retrospectively analyzed. Data analyzed included demographic details, clinical features, type of CCF, and response to therapy. Outcomes were categorized as complete cure, partial cure, and no cure or worsening. Patients with complete and partial cure were grouped as good outcome whereas those with no cure or worsening as poor outcome.

RESULTS

A total of 44 patients were advised IMCC for low-flow CCF, of whom five were lost to follow-up. Results of the remaining 39 patients were analyzed, of whom 21 (53.8%) were males. The mean age at presentation was 54.38 ± 14.54 years. The median duration between the onset of symptoms and presentation was 5.0 ± 4.10 months. The common presenting features were episcleral congestion and proptosis (89.7%), extraocular motility restriction (66.7%), and diplopia (48.7%). Most common CCF type was type D (34, 87.2%). All patients were advised to undergo IMCC. Good outcome was seen in 35 patients (89.7%, 95% CI: 80.2% to 99.2%), whereas poor outcome was seen in four (10.3%) patients. The mean duration of follow-up was 15.91 ± 21.87 months.

CONCLUSION

The present study found a good outcome with IMCC in 89.7% cases of indirect low-flow CCF with no major complications. It should be considered the management of choice in patients who are systemically unfit or cannot afford endovascular embolization.

Venous outflow-targeted coil embolization of direct carotid-cavernous fistulas

BACKGROUND

Coil embolization is the mainstay treatment for carotid-cavernous fistulas (CCFs). However, few studies have reported entire occlusion of engorged veins to interrupt venous outflow. We report our experience with venous outflow-targeted coil embolization of direct CCFs.

METHODS

We retrospectively reviewed all the patients diagnosed with direct CCFs treated with venous outflow-targeted coil embolization between November 2013 and February 2020. Venous outflow-targeted coil embolization of the CCFs was performed as follows. First, transarterial stent-assisted coil embolization of CCFs was performed. If the venous outflow to the engorged veins persisted after transarterial stent-assisted coil embolization, entire occlusion of the engorged veins and additional coil packing within the cavernous sinus were performed to interrupt the venous outflow.

RESULTS

Ten patients had undergone venous outflow-targeted coil embolization, 6 women (60%) and 4 men (40%). Transfemoral cerebral angiography showed high-flow, direct CCFs in all the patients. Venous outflow occurred through the superior ophthalmic vein (SOV) in all the patients and was completely interrupted by the entire occlusion of the engorged veins with fibered coils. Three patients (30%) had undergone additional treatment in a supplementary manner because of recurrent symptoms (chemosis in 1 patient, faint tinnitus in 2 patients) in the early postprocedural period (1 to 4 weeks). All the symptoms were resolved on follow-up. No additional recurrence was found during follow-up (1-75 months). No peri-procedural complications were encountered.

CONCLUSIONS

Venous outflow-targeted coil embolization of CCFs would be a safe and effective treatment method.

Neovascular glaucoma with combined retinal vascular occlusion in carotid cavernous fistula

Carotid cavernous fistulas (CCFs) can present with varied ophthalmic manifestations. The most important vision-threatening complications of CCF include glaucoma and retinal vascular occlusions. We report a case of a man in his early 30s who developed a post-traumatic direct CCF. The patient denied undergoing embolisation therapy. This resulted in aggravation of his condition with onset of combined retinal venous and artery occlusion leading to neovascular glaucoma and severe vision loss. He was treated with medical management followed by diode laser photocoagulation to control intraocular pressure. Diagnostic cerebral angiography done 3 months later showed complete closure of the fistula; hence, no further intervention was advocated. Combined vascular occlusion is a rare vision-threatening occurrence in cases of CCF. Timely intervention with closure of the fistula can prevent the development of vision-threatening complications.

High index of suspicion: diagnosing a carotid-cavernous fistula

A woman in her 70s presented with acute bilateral retro-orbital headache, diplopia, chemosis and eye swelling. Ophthalmology and neurology were consulted after detailed physical examination and diagnostic workup including laboratory analysis, imaging and lumbar puncture. The patient was diagnosed with non-specific orbital inflammation and was started on methylprednisolone and dorzolamide-timolol for intraocular hypertension. The patient's condition improved slightly, but a week later, she developed subconjunctival haemorrhage in the right eye, which prompted investigation for a low-flow carotid-cavernous fistula. Digital subtraction angiography showed bilateral indirect carotid-cavernous fistula (Barrow type D). The patient underwent bilateral carotid-cavernous fistula embolisation. Her swelling improved considerably on day 1 after the procedure and her diplopia improved over the following weeks.

Outcomes After Endovascular Treatment of Direct Carotid Cavernous Fistulas: Systematic Review and Meta-Analysis

BACKGROUND

Direct carotid cavernous fistulas (dCCF) involve pathologic shunting from the internal carotid artery into the cavernous sinus. We systematically reviewed the methods and outcomes of endovascular therapy for dCCF.

METHODS

PubMed, Scopus, and EMBASE were used to identify studies that reported outcomes for patients undergoing embolization of dCCF. Outcomes included rates of occlusion, complications, symptom improvement, and recurrence. Pooled rates for each outcome were obtained with random effects models. The influence of embolization method on outcomes was assessed with meta-regressions.

RESULTS

There were 16 studies comprising 270 patients. The mean age was 39.6 years, there were 36.3% females, and the mean follow-up was 19.7 months. Coils were the most common method of embolization (69.3%), followed by Onyx (31.1%), covered stent (22.2%), N-butyl cyanoacrylate (6.7%), and flow diversion (4.8%). The pooled overall occlusion rate was 92.1% (95% confidence interval [CI], 86.3-95.6; I2 = 29.2%). The pooled complication rate was 10.9% (95% CI, 7.3-16; I2 = 0%). Use of coils were associated with a slightly lower odds of overall complications (odds ratio, 0.98; 95% CI, 0.97-0.99) and cranial nerve palsy (odds ratio, 0.98; 95% CI, 0.97-0.99). The pooled fistula recurrence rate was 8.3% (95% CI, 4.3-15.4; I2 = 30.9%).

CONCLUSIONS

Endovascular therapy for dCCF is associated with high occlusion and low complication rates. Recurrence is not uncommon, highlighting the need for close follow-up.

Transfacial venous embolisation of a spontaneous indirect paediatric caroticocavernous fistula

We present a rare case of a spontaneous indirect caroticocavernous fistula (CCF) in an early adolescent, who exhibited a 1-month history of redness, decrease in vision and proptosis of the right eye without a history of trauma or connective tissue disorder. An MRI of the brain and orbit and a digital subtraction angiography confirmed the diagnosis of Barrow type D CCF. The same was then treated with coiling and a liquid embolising agent using the transfacial venous route, resulting in complete obliteration. Reduction in conjunctival congestion with mild improvement in visual acuity was noted postprocedure. Complete recovery was noted at the 6-month follow-up visit. CCF, though rare in the paediatric population, should be highly considered in the differential diagnosis when the above-mentioned complaints are present. Early diagnosis and intervention have favourable outcomes.

Incomplete Third Nerve Palsy Due to a Carotid-Cavernous Fistula

INTRODUCTION

The approach to oculomotor nerve palsies involves the exclusion of compressive, infective, inflammatory, or ischemic lesions. Dural arteriovenous fistulae, including carotid-cavernous fistulae (CCF), are known causes of third nerve palsy. However, diagnosis can sometimes be delayed or missed due to the various clinical presentations. CCF remains a rare but treatable cause of third nerve palsy.

CASE REPORT

A 63-year-old Chinese female presented to our unit with gradual onset horizontal diplopia. Clinical examination revealed a partial left oculomotor nerve palsy without congestive eye symptoms. A cerebral angiogram revealed a left indirect CCF supplied by the inferolateral trunk of the left internal carotid artery. She underwent successful transvenous embolization. She improved postprocedure and was discharged well on day 10 of her admission. She was reviewed at 2 months follow-up and had recovered completely.

CONCLUSION

Our case is a classic description of a CCF with posterior drainage into the inferior petrosal sinus. We hope this case and a review of the literature can serve as a reminder to clinicians of the varied presentations of CCF. We believe this case adds value to the clinicians in contributing to their diagnostic process and to our interventional colleagues in highlighting a case with a successful postembolization outcome.