Asystole during onyx embolisation of a dural AV fistula: The trigeminocardiac reflex

A case report of multi-step management of extracranial carotid artery aneurysm and carotid-cavernous fistula combination in patients

Extracranial carotid artery aneurysms (ECAA) and carotid-cavernous fistulas (CCF) are rare arterial pathologies with severe complications and increased risk of mortality. The optimal treatment approach for this combined condition is a topic of debate among neurosurgeons and neuroradiologists, and a standardized treatment protocol has yet to be established. The aim of this case report was to demonstrate the management of a rare combination of ECAA and CCF in patients. The treatment strategy included a two-step procedure of endovascular embolization of CCF followed by dual antiplatelet therapy and endovascular stenting of an aneurysm. Control angiograms showed the exclusion of an aneurysm from the blood circulation and CCF symptoms were resolved.

Case Report: Trigeminocardiac Reflex in Endovascular Recanalization of Intracranial Internal Carotid Artery Occlusion

Background

The trigeminocardiac reflex (TCR) is a unique brainstem reflex that manifests as sudden negative hemodynamic changes. Although rare, TCR may develop during interventional neuroradiology procedures. Intracranial internal carotid artery occlusion (ICAO) is a cause or risk factor of ischemic stroke. Endovascular recanalization is an effective treatment for intracranial ICAO. The occurrence of TCR during the endovascular treatment of intracranial ICAO has not been reported previously.

Methods

We identified and reviewed four intracranial ICAO cases who suffered a sudden negative hemodynamic change during endovascular therapy at our hospital between March 2019 and December 2020.

Results

There were five sudden heart rate and/or blood pressure drops in the four cases; all occurred just after contrast agents were injected. Some angioarchitectural characteristics were common among the four cases. First, the intracranial internal carotid artery distal to the ophthalmic artery was occluded, leaving the ophthalmic artery as the only outflow tract. Second, there were obstructive factors proximal to the end of the guiding catheter, including a vasospasm or dilated balloon. This type of angioarchitecture with a limited outflow tract creates a “blind alley.” The five negative hemodynamic events all recovered: two spontaneously and three after drug administration. Postoperatively, two of the four patients developed ocular symptoms.

Conclusions

Intracranial ICAOs may produce a distinctive angioarchitecture, such as a blind alley, that predisposes patients to TCR. Surgeons should pay special attention to the possibility of TCR during the endovascular recanalization of intracranial ICAO. Low-pressure contrast injections should be attempted, and anticholinergics should be ready for use.

Transvenous Approaches to Embolization of Dural Arteriovenous Fistulae of the Cavernous Sinus

Dural arteriovenous fistulae of the cavernous sinus (CS) (previously often referred to indirect carotid cavernous fistulas) are rare vascular shunts involving meningeal branches and osseous branches of the external or internal carotid arteries and the CS. They typically present with ocular symptoms including pain, conjunctival injection, and proptosis. Left untreated there may be a risk of vision loss, and fistulas with cortical venous reflux through either the deep or superficial venous system may cause intracranial venous congestion or hemorrhage. Endovascular embolization is the standard treatment, and while transarterial routes may appear possible, transarterial embolization has considerable risks of ischemic complications. Conversely, transvenous routes achieve a high rate of fistula occlusion with a low risk of peri-procedural morbidity. Procedural success depends on identification of the venous outflows from the fistula and localization of the fistulous point, to select the best route of access to the CS, including the inferior petrosal sinus (IPS), intercavernous sinus, or superior ophthalmic vein, among others. Even if the IPS is not visualized, it may be possible to recanalize it to gain access to the CS. Embolization can be performed with a combination of coils, fibered coils, and liquid embolic agents, focusing on occlusion of the fistulous point or blocking high-risk venous outflow pathways. In this review we will highlight procedural pearls and potential pitfalls and our typical approach to these lesions based on illustrative examples.

Brain and Heart Crosstalk During Neurointerventional Procedures: The Role of the Trigeminocardiac Reflex: An Updated Systematic Review

The trigeminocardiac reflex is a well-described brainstem reflex that clinically manifests as bradycardia, hypotension, or apnea. This physiological phenomenon is extensively reported during open neurosurgical procedures, but very few data exist for trigeminocardiac reflex occurrence during neurointerventional procedures. This systematic review aims to provide aggregated information related to the trigeminocardiac reflex during neurointerventional procedures and to improve understanding of the various mechanisms that can incite this unique brain-heart crosstalk.

Outcomes After Onyx Embolization as Primary Treatment for Cranial Dural Arteriovenous Fistula in the Past Decade

RATIONALE AND OBJECTIVES

This retrospective single-center study aims to evaluate endovascular therapy (EVT) of cranial dural arteriovenous fistulas (dAVF) with ethylene vinyl alcohol (EVOH) copolymer (Onyx) regarding occlusion rates, complications, and recurrences.

MATERIAL AND METHODS

From January 2008 to April 2018, 75 patients with dAVF (41 men, 34 women; mean age 56 years) underwent EVT with the nonadhesive liquid embolic agent as primary treatment. Patient records and angiograms were reviewed for demographic data, symptoms, fistula type and size, number of EVTs, amount of embolic material, occlusion rates, and recurrences.

RESULTS

Seventy-five patients with dAVFs were primarily embolized with EVOH in 96 EVTs. According to the Merland-Cognard classification the majority of dAVFs treated were type 4 (42.7%), followed by type 2a (18.7%), type 2a+b (17.3%), type 1 (8%), type 2b (5.3%), type 3 (5.3%), and type 5 (2.7%). Complete occlusion (CO) of the dAVF was achieved in 45/75 (60%) of cases after a single EVT and in 58 (77%) patients after one or several EVTs. Seven patients (9%) required additional surgical therapy for CO. Successful treatment was achieved for 70/75 (93%) patients including 10 (13%) patients with residual dAVFs type 1-2a. Recurrence after CO occurred in one (1.3%) patient and four (5.3%) patients remained refractory to therapy with dAVFs type > 2a. Procedure-related permanent morbidity occurred in 4/75 (5.3%) patients.

CONCLUSION

For more than a decade transarterial EVOH embolization has established as the first-line treatment for cranial dAVFs with high cure rates and low rates of complications and recurrences. Additional neurosurgical therapy is rarely required for curative treatment.

Endovascular treatment of the cavernous sinus dural arteriovenous fistula: current status and considerations

A cavernous sinus dural arteriovenous fistula (CS-DAVF) is an abnormal arteriovenous communication involving the dura mater within or near the CS wall. The dural arteries from the internal carotid artery and external carotid artery supply the CS-DAVF, and the superior ophthalmic vein (SOV) and inferior petrous sinus (IPS) are frequent venous drainers. In CS-DAVF cases, high-risk lesions require treatment. Endovascular treatment (EVT) has been the first-line option for CS-DAVFs. To our knowledge, a review of the EVT of CS-DAVFs is lacking. Therefore, in this paper, we review the available literature on this issue. In addition, some illustrative cases are also provided to more concisely expound the EVT of CS-DAVFs. According to the recent literature, transvenous embolization via the IPS is considered the most effective method for EVT of CS-DAVFs. In addition, the transorbital approach is another reasonable choice. Other venous approaches can also be tried. Because of the low cure rate, transarterial embolization for CS-DAVFs is limited to only highly selected patients. In the EVT of CS-DAVFs, various agents have been used, including coil, Onyx, and n-butyl cyanoacrylate, with coil being the preferred one. In addition, when EVT cannot obliterate the CS-DAVF, stereotactic radiotherapy may be considered. In general, despite various complications, EVT is a feasible and effective method to manage CS-DAVFs by way of various access routes and can yield a good prognosis.