Hemorrhage from Arteriovenous Malformations and Its Management

18 Hemorrhage from Arteriovenous Malformations and Its Management

Ross Puffer and Giuseppe Lanzino

Abstract

Arteriovenous malformations (AVMs) are responsible for up to 4% of primary intracerebral hemorrhages, and in population-based studies, the incidence of hemorrhage at presentation is 50-65%. The current AVM literature was searched to determine rates of hemorrhage and outcome after rupture. Recommendations for the medical management of intracranial hemorrhage have been taken from the most recent American Heart Association/American Stroke Association guidelines, as well as notable trials that were performed to determine adequate blood pressure guidelines after primary intracerebral hemorrhage, such as ADAPT and INTERACT. We found that treatment guidelines follow those of primary intracerebral hemorrhage. Systolic blood pressure < 140 mmHg, treatment of raised ICP and normoglycemia, but despite best medical management, patients can experience complications including include seizures, vasospasm (rare), and deep venous thrombosis. Ultimately, AVM associated hemorrhages have better functional outcomes when compared to primary intracerebral hemorrhages.

Keywords: arteriovenous malformation, complications, hemorrhage, management

Key Points

Between 50 and 65% of arteriovenous malformations (AVMs) present with hemorrhage.
The timeframe of progression and involvement of multiple vascular territories may lead the clinician to consider AVM as a source of a hemorrhage.
Treatment guidelines follow those of primary intracerebral hemorrhage: Systolic blood pressure < 140 mm Hg, treatment of raised intracranial pressure and normoglycemia.
Complications after AVM rupture include seizures, vasospasm (rare), and deep venous thrombosis.
AVM-associated hemorrhages have better functional outcomes when compared to primary intracerebral hemorrhages.

18.1 Introduction

Arteriovenous malformations (AVMs) are responsible for up to 4% of primary intracerebral hemorrhages, and in population-based studies, the incidence of hemorrhage at presentation is 50 to 65%.¹^,²^,³ Hemorrhage from AVM ruptures often occurs within the brain parenchyma, but up to 34% of patients can present with intraventricular hemorrhage (IVH) either isolated or associated with hemorrhage in other compartments, and 24% may have some elements of subarachnoid hemorrhage (SAH) as well.²^,³^,⁴ In many cases (93%), the intracranial hemorrhage occurs due to rupture of the AVM nidus; however, the hemorrhage can also be related to AVM-associated arterial aneurysms (approximately 7% of cases).³ Patients with AVMs may experience a microhemorrhage which is clinically silent but evident on imaging.⁵ Functional outcome after AVM rupture is better than in patients with primary intracerebral hemorrhage. In a recent study, patients who suffered ICH from an AVM had significantly better National Institute of Health Stroke Scale (NIHSS) score at 30-day follow-up than patients with spontaneous (non-AVM related) ICH (mean NIHSS of 3.9 ± 6.2 vs. 13.6 ± 9.5, respectively).⁶ Often, AVM patients are younger, have lower blood pressure at admission, and higher GCS than patients with spontaneous ICH.⁷ Despite these better reported outcomes when compared to spontaneous ICH, the fatality rate after AVM rupture has been found to be 11% at 1 month, increasing to 13% at 2 years. At 1 year postrupture, 40% of patients are dead or dependent (modified Rankin scale [mRS] ≥ 3).⁷

With advances in noninvasive imaging techniques, it has become apparent that several patients with the so-called unruptured AVMs have indeed radiological evidence of prior bleeding as indicated by T2 and FLAIR changes in the parenchyma around the AVM and in some cases frank cyst formation, most likely the result of previous subclinical bleeding. This is corroborated by direct and histopathological analysis after AVM excision.⁵ These patients are considered to have suffered from a subclinical hemorrhage with no or very mild symptoms at the time of rupture. The true significance of these findings in relation to the natural history of these AVMs is unknown. However, this observation underscores that not all unruptured AVMs are the same, given that some patients may have suffered a prior hemorrhagic episode without noticeable clinical effects.⁵

18.2 Materials and Methods

The current AVM literature was searched to determine rates of hemorrhage and outcome after rupture. Recommendations for the medical management of intracranial hemorrhage have been taken from the most recent American Heart Association/American Stroke Association guidelines, as well as notable trials that were performed to determine adequate blood pressure guidelines after primary intracerebral hemorrhage, such as ADAPT and INTERACT.⁸^,⁹^,¹⁰

18.3 Results and Discussion

18.3.1 Initial Management of a Ruptured Arteriovenous Malformation

As discussed previously, AVMs may present with hemorrhage in 50 to 65% of cases, and the symptoms present at onset depend on the location and severity of the hemorrhage.²^,³ Small localized bleeds or simple SAH may manifest with headache with various characteristics in relation to the degree of blood extravasation and location. Hemorrhages near the cortical surface may lead to clinical seizures (in up to 33% of patients), and indeed an initial seizure as clinical presentation of an AVM warrants careful evaluation because seizures can be a symptom of hemorrhage even in the absence of headache. Deeper lesions and lesions adjacent to eloquent areas may present with motor, sensory, language, or visual symptoms.¹¹ AVM-associated hemorrhages can involve multiple vascular territories, and this may be a clue leading the clinician to an AVM as the cause rather than primary intracerebral hemorrhage. These symptoms may progress over minutes to hours from accumulation of blood products, local brain compression, and elevated intracranial pressure (ICP). The temporal relationship of symptom progression is often distinct from that of aneurysmal SAH, given its progression over minutes to hours rather than sudden, acute onset of maximum intensity in cases of aneurysmal SAH. Large parenchymal bleeds and/or intraventricular extension can be associated with rather rapid decline of the level of consciousness and progression to coma.

Initial management largely follows the same guidelines as primary intracerebral hemorrhage, with cardiorespiratory support and transfer to specialized medical attention as mainstays of initial management. After initial stabilization, neuroimaging should be obtained to determine the location, size, and possible source of intracranial hemorrhage. This should be completed using CT as the first screening image modality (class I, level A evidence).⁹ CT angiography can be obtained if an AVM is considered a possible source of the hemorrhage because of location, clinical factors, and patient age. This modality allows for rapid identification of an AVM in patients who may need urgent decompressive surgery and may also demonstrate associated aneurysms. Despite advances in modern CT angiography techniques, catheter-based angiography remains the gold standard. Nonetheless, vascular imaging should be considered if an AVM is thought to be the source (class IIa, level B).⁹ If the patient does not require emergent, decompressive surgery, a catheter-based angiography should be performed within 24 hours if possible. This allows for the identification of any associated aneurysms, as well as the possible source of the intracranial hemorrhage (► Fig. 18.1).¹²

Fig. 18.1 Selective occlusion of rupture point in ruptured arteriovenous malformations (AVMs). This 63-year-old man had a known AVM diagnosed in 2007 after a seizure. No treatment was recommended because of the unruptured status and the risks of treatment. Nine years later, he presented with sudden headache and left-sided weakness. Head CT shows a deep hemorrhage (a,b). (c) Catheter angiography, left vertebral artery injection, shows a diffuse AVM with perinidal aneurysms (arrowhead). (d) Three-dimensional angiography shows the mass of the AVM and the perinidal aneurysms (arrowhead). (e) Dynamic CT shows that the perinidal aneurysms are in direct continuity with the hemorrhage and at the epicenter of it. Thus, these aneurysms are most likely the source of the hemorrhage. (f) Superselective catheterization of the feeding pedicle provides better definition of the perinidal dysplastic aneurysms (arrowheads). (g) The pedicle harboring the aneurysms was occluded with detachable coils (arrowhead)to decrease the risk of rehemorrhage.