Resection Of Arteriovenous Malformations Research Articles

Computed tomography angiography based emergency microsurgery for massive intracranial hematoma arising from arteriovenous malformations

Digital subtraction angiography (DSA) and magnetic resonance angiography are the imaging modalities for the detection of intracranial arteriovenous malformations. However, these modalities are time consuming and cannot be used in emergency conditions. Computed tomography angiography (CTA) has also been shown to reliably detect vascular disorders such as cerebral arteriovenous malformations (AVMs). The purpose of this study was to evaluate the usefulness CTA in the surgical treatment of AVMs and the hematoma evacuation. Case records of 18 patients with massive intracranial hematoma secondary to AVMs were retrospectively reviewed. All patients had emergent brain CT and CTA. Follow-up DSA was performed two to three weeks after surgery. The outcome was assessed using Glasgow Outcome Scale (GOS). Results : Emergent CTA demonstrated AVMs and defined the feeding arteries, abnormal vascular nest, and draining veins in all the patients. Fourteen patients underwent hematoma evacuation and total resection of the AVMs, and four patients had hematoma evacuation and a partial resection. Follow-up DSA demonstrated complete resection of AVM in 14/18 patients and partial resection in 4 patients. There were no deaths and none of the patients had rebleeding in the follow up. A GOS scores during follow-up were: GOS 3 in 12 patients, GOS 4 in 4 patients and GOS 2 in 2 patients. CTA can be a reliable and rapid diagnostic tool for detecting underlying AVM in patients presenting with intracranial hematoma and for the pretreatment planning of emergency craniotomy.

Three-Dimensional Magnetic Resonance Imaging Based on Time-of-Flight Magnetic Resonance Angiography for Superficial Cerebral Arteriovenous Malformation -Technical Note-

Direct surgery remains important for the treatment of superficial cerebral arteriovenous malformation (AVM). Surgical planning on the basis of careful analysis from various neuroimaging modalities can aid in resection of superficial AVM with favorable outcome. Three-dimensional (3D) magnetic resonance (MR) imaging reconstructed from time-of-flight (TOF) MR angiography was developed as an adjunctive tool for surgical planning of superficial AVM. 3-T TOF MR imaging without contrast medium was performed preoperatively in patients with superficial AVM. The images were imported into OsiriX imaging software and the 3D reconstructed MR image was produced using the volume rendering method. This 3D MR image could clearly visualize the surface angioarchitecture of the AVM with the surrounding brain on a single image, and clarified feeding arteries including draining veins and the relationship with sulci or fissures surrounding the nidus. 3D MR image of the whole AVM angioarchitecture was also displayed by skeletonization of the surrounding brain. Preoperative 3D MR image corresponded to the intraoperative view. Feeders on the brain surface were easily confirmed and obliterated during surgery, with the aid of the 3D MR images. 3D MR imaging for surgical planning of superficial AVM is simple and noninvasive to perform, enhances intraoperative orientation, and is helpful for successful resection.

Recurrence of a cerebral arteriovenous malformation following complete surgical resection: A case report and review of the literature

Background:Angiography-confirmed complete resection of an arteriovenous malformation (AVM) has traditionally been considered curative. However, recurrence of AVM following angiographically proven complete resection does exist, especially in children. This rare occurrence has been reported 29 times in the English language literature. Although recurrence may be asymptomatic, many reported cases result in epilepsy or intracranial hemorrhage anywhere from 0.5 to 9 years following complete resection. We report a rare case of AVM recurrence that became symptomatic 16 years after complete resection. We review the literature and discuss the relevance of performing follow-up imaging to detect AVM recurrence.Case Description:An 8-year-old girl presented with a right occipital hemorrhage with intraventricular extension from a ruptured AVM of the right occipital lobe. She underwent AVM resection through a right occipital craniotomy. Postoperative angiography confirmed complete resection and she made an uneventful recovery. Sixteen years later, she presented with a 2-month history of headaches, nausea and dizziness. Angiography revealed recurrence of the AVM which was completely resected, as documented on postoperative angiography.Conclusion:In children, an AVM may recur after angiography-proven complete resection. Recurrence may be due to persistence and growth of an initially angiographically occult arteriovenous shunt left in place during surgery or the development of a new AVM. In addition to obtaining follow-up angiography 6-12 months after surgery, a late angiography 5 years after resection may be warranted in patients at risk for recurrence. Asymptomatic recurrence detection allows treatment and may prevent the morbidity associated with intracranial hemorrhage.

Cranio-spinal migration of a metallic clip placed during arteriovenous malformation resection - A case report, review of the literature, and management strategies

BackgroundMicroclip placement during AVM resection is generally accepted to be a safe practice in neurosurgery. Here, we describe an unusual complication involving cranio-spinal clip migration discovered five years after the initial AVM surgery.Case PresentationA 53-year-old man underwent resection of a superior vermian AVM that required the placement of two microclips during the procedure. Five years after surgery, the patient suffered from descending sensory radiculopathy that resolved spontaneously. The workup revealed cranio-spinal migration of one of the previously placed microclips.ConclusionsAVM clip migration is a rare phenomenon; however, the diagnosis should be entertained in patients with posterior fossa instrumentation who suffer from unusual neurologic symptoms.

Intraoperative angiography during microsurgical removal of arteriovenous malformations in children

Confirming the successful management of pediatric arteriovenous malformations (AVMs) requires high-quality postoperative digital subtraction angiography. Although the role of intraoperative angiography during the microsurgical removal of AVMs is well established in adults, the technique has several limitations including poor image quality, uniplanar image acquisition, and absent full heparin protection. Here, the authors report on their experience with high-quality intraoperative angiography during the surgical management of pediatric AVMs in their image-guided therapy (IGT) facility. The authors retrospectively reviewed the demographic, clinical, and radiological characteristics of 22 patients who underwent the surgical management of AVMs at the Hospital for Sick Children in Toronto, with the aid of high-quality intraoperative or immediate postresection cerebral angiography via a transfemoral approach. Between January 2000 and August 2009, 18 children (mean age 13.05 ± 4.04 years, range 4-21 years) underwent both surgical management of an AVM and intraoperative cerebral angiography at an IGT facility. An additional 4 children underwent angiography immediately after surgery in the regular operating room while under the same anesthesia. The mean AVM size was 2.55 ± 1.43 cm (range 1-6 cm) with a mean Spetzler-Martin grade of 2.27 (range 1-4). Intraoperative angiography in 4 of the 18 patients demonstrated residual AVM requiring additional resection. One patient demonstrated residual AVM on immediate postoperative angiography and underwent immediate reoperation. Successful excision of the residual AVM was confirmed on angiography the following day in that case. Procedural complications occurred in connection with 1 (3.3%) of 30 angiograms, including asymptomatic transient nonfilling of an ophthalmic artery, which was resolved on follow-up angiography. Negative intraoperative angiograms were confirmed with follow-up angiograms in 15 (93.75%) of 16 patients at a mean of 9.93 ± 5.70 months. One patient with a negative intraoperative angiogram demonstrated a tiny residual AVM on follow-up angiography at 8 months (false-negative rate 6.25%), but had a negative preoperative angiogram 1 year later in the IGT facility. No patient with a negative intraoperative angiogram required further AVM-directed treatment. Intraoperative angiography is a safe and effective adjunct to the surgical management of AVMs in children. This novel approach allows the pre-, intra-, and postoperative acquisition of high-quality images, which can help guide the resection of AVMs, especially those that are small, diffuse, or of a complex angioarchitecture.

The Impact of Microscope-Integrated Intraoperative Near-Infrared Indocyanine Green Videoangiography on Surgery of Arteriovenous Malformations and Dural Arteriovenous Fistulae

Microscope-based intraoperative near-infrared indocyanine green (ICG) videoangiography is useful as an adjunct to intra- or postoperative digital subtraction angiography (DSA) in aneurysm surgery. To evaluate intraoperative ICG videoangiography for surgery of arteriovenous malformations (AVMs) and dural arteriovenous fistulas (dAVFs). Seventeen patients undergoing surgical resection of intracranial AVM or AVF were enrolled into this prospective evaluation. ICG videoangiography sequences were analyzed with regard to transit times to differentiate between arterial, early venous, capillary, and venous phase as well as early passage (fistula) and delayed appearance (ischemia). ICG videoangiography was compared with pre- and postoperative angiography. Forty-six ICG videoangiographies were performed in 17 operative procedures. In 41 ICG investigations image quality and spatial resolution were excellent to analyze arterial, early venous, capillary, and venous phase. In 2 cases ICG videoangiography provided additional information to change the surgical strategy. With the exception of one case only, the postoperative angiogram corresponded to the last ICG examination performed after the resection. No side effects related to ICG injection were observed. In one patient with a deep thalamic AVM the final ICG investigation was inconclusive owing to insufficient illumination of the deep surgical field. Microscope-integrated repetitive ICG videoangiography during AVM and dAVF surgery is fast, easy to perform, and safe. This simple and safe real-time method is a useful additional tool that can potentially lower the surgical risk in complex AVMs and help avoid missed residuals.

Frameless Stereotactic Radiosurgery for Arteriovenous Malformations

Stereotactic radiosurgery (SRS) is an effective alternative to microsurgical resection or embolization for arteriovenous malformations (AVMs). Digital subtraction angiography (DSA), with its superior vascular resolution and ability to account for contrast flow dynamics, is the gold standard for diagnosis and characterization of vascular anatomy. Other modalities, including CT angiography (CTA) and MR angiography (MRA), are used for complementary information. In traditional SRS a frame fixed on the skull plays an essential role.

Microvascular Anatomy of the Medial Temporal Region

The medial temporal region (also called the temporomesial or mediobasal temporal region) is the site of the most complex cortical anatomy. To investigate the anatomic variability of the arterial supply and venous drainage of each segment of the medial temporal region (MTR), and to discuss and illustrate the implications of the findings for surgery of arteriovenous malformations (AVM) of the MTR. Forty-seven cerebral hemispheres and 10 silicon-injected cadaveric heads were examined using x3 to x40 magnification. Illustrative surgical cases of MTR AVMs were selected. The anterior choroidal artery (AChA) gave rise to an anterior uncal artery in 83% of hemispheres and a posterior uncal or unco-hippocampal artery in 98%. The plexal segment of the AChA gave off neural branches in 38%. The MCA was the site of origin of anterior uncal, unco-parahippocampal, or anterior parahippocampal arteries in 94% of hemispheres. An anterior uncal artery arose from the internal carotid artery (ICA) in 45% of hemispheres. The posterior cerebral artery (PCA) irrigated the entorhinal area through its anterior parahippocampal or hippocampo-parahippocampal branches in every case. A PCA bifurcation was identified in 89% of hemispheres, typically at the middle segment of the MTR. The most common pattern of bifurcation was by division into posteroinferior temporal and parieto-occipital arterial trunks. The anterior segment of the basal vein had a predominant anterior drainage in 35% of hemispheres, and the middle segment had a predominant inferior drainage in 16%. An understanding of the vascular variability of the MTR is essential for accurate microsurgical resection of MTR AVMs.

Interventions for treating brain arteriovenous malformations in adults.

Brain arteriovenous malformations (AVMs) are the single most common cause of intracerebral haemorrhage in young adults. Brain AVMs also cause seizure(s) and focal neurological deficits (in the absence of haemorrhage, migraine or an epileptic seizure); approximately one fifth are incidental discoveries. Various interventions are used in an attempt to eradicate brain AVMs: neurosurgical excision, stereotactic radiotherapy/'radiosurgery' (using gamma knife, linear accelerator, proton beam, or 'Cyber Knife'), endovascular embolisation (using glues, particles, fibres, coils, or balloons), and staged combinations of these interventions. This is an update of a Cochrane review first published in 2006. To assess the clinical effects of interventions to treat brain AVMs in adults (with the aim of either partial obliteration or total eradication), using data published in randomised controlled trials (RCTs). We searched the Cochrane Stroke Group Trials Register (last searched November 2009), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2009), MEDLINE (1966 to November 2009) and EMBASE (1980 to November 2009). We searched international registers of clinical trials, the contents pages of relevant journals, and bibliographies of relevant articles (November 2009). We also contacted manufacturers of interventional treatments for brain AVMs (March 2005). We sought randomised trials of any or all of the interventions for brain AVMs, compared against each other or against usual medical therapy, with relevant clinical outcome measures. Two authors independently applied the inclusion criteria and reviewed the relevant studies. One ongoing RCT fulfils the selection criteria for this review: A Randomized trial of Unruptured Brain Arteriovenous malformations (ARUBA, www.arubastudy.org), comparing interventional treatment versus medical management for brain AVMs that have never bled. We also found two RCTs which tested the equivalence of two embolic agents for the pre-operative embolisation of brain AVMs (one published, one unpublished), but none of the primary or secondary outcome measures in these trials met our desired criteria. We also excluded a third RCT which studied three different blood pressure lowering treatments to induce deliberate hypotension during surgical resection of brain AVMs because the intervention was not the focus of this review. There is no evidence from randomised trials with clear clinical outcomes comparing different interventional treatments for brain AVMs against each other or against usual medical therapy to guide the interventional treatment of brain AVMs in adults. One such trial (ARUBA) is ongoing.

E-041 Combined endovascular embolization and surgical resection of a massive lumbosacral arteriovenous malformation in a patient with Cobb syndrome

Objective and importanceCobb syndrome is a rare condition that includes a cutaneous nevus with an associated spinal vascular lesion at the same dermatome. We present a challenging case of a...

O-007 Treatment of pial arteriovenous malformations: single institution experience at Children's hospital boston

IntroductionPediatric cerebral arteriovenous malformations (AVMs) present an ongoing risk of hemorrhage compounded by long life expectancy. AVMs can be treated with microsurgery, embolization or radiosurgery, alone or in combination. We...

Dynamic Autoregulation Testing Does Not Indicate Changes of Cerebral Blood Flow Before and After Resection of Small- and Medium-Sized Cerebral AVM

This study tested the hypothesis that dynamic cerebral autoregulation (AR) remains intact before and after the excision of human arteriovenous malformations (AVM). In 12 patients (six female and six male; mean age, 34years) harboring cerebral AVMs (AVM group), and 15 patients (nine female/six male; mean age, 49years) with deep-seated lesions (e.g., small frontobasal meningiomas) approached by transsylvian dissection (control group), we continuously assessed cerebral blood flow (CBF) using a thermo-diffusion technique, and mean arterial blood pressure (MABP). AR was estimated post-hoc using correlation-coefficient autoregulatory-index (Mx) analysis. Measurements were compared according to groups (AVM/control) and times (pre/post), referred to as conditions before and after AVM resection and transsylvian dissection, respectively. All values are given as mean ± SD. The correlation index Mx was without significant difference among the study groups, indicating unimpaired autoregulatory function. Intragroup comparisons related to AVM nidus size (small- (≤3cm) and medium-sized (3-6cm)) did not show significant influence on autoregulation. The study shows that in patients harboring small- and medium-sized AVMs, dynamic autoregulatory function as estimated by correlation-coefficient index analysis seems to be intact in the surrounding cerebrovascular bed perioperatively.

Supracerebellar-Supratrochlear and Infratentorial-Infratrochlear Approaches

Lateral supracerebellar-infratentorial approaches are established for lesions in ambient cistern and posterolateral midbrain, but published surgical experiences do not describe results with this approach in the sitting position. Gravity retraction of the cerebellum opens this surgical corridor and dramatically alters exposure, creating 2 variations of the lateral supracerebellar-infratentorial approach: the supracerebellar-supratrochlear approach and the infratentorial-infratrochlear approach. We reviewed our experience treating cavernous malformations and arteriovenous malformations (AVMs) of the posteroinferior thalamus and posterolateral midbrain by use of supracerebellar-supratrochlear and infratentorial-infratrochlear approaches. Microsurgical technique, clinical data, radiographic features, and neurological outcomes were evaluated. During an 11-year surgical experience with 341 cavernous malformation patients and 402 AVM patients, 8 patients were identified, 6 with cavernous malformations and 2 with AVMs. Infratentorial-infratrochlear approaches were used in 4 patients (50%), including 3 with inferolateral midbrain cavernous malformations. Supracerebellar-supratrochlear approaches were used in 4 patients (50%), including 2 with posterior thalamic lesions surfacing on pulvinar. Resections were radiographically complete in all cases. There were no new, permanent neurological deficits, nor were there any medical or surgical complications. There has been no evidence of rebleeding or recurrence. Gravity retraction of the cerebellum transforms the lateral supracerebellar-infratentorial approach, enhancing exposure and approach trajectories that can be achieved with patients in prone or lateral positions. The increased upward viewing angle of the supracerebellar-supratrochlear approach accesses the posteroinferior thalamus. The increased downward-viewing angle of the infratentorial-infratrochlear approach accesses cerebellomesencephalic fissure and posterolateral midbrain. These approaches open wide corridors for safe surgical resection of symptomatic cavernous malformations and AVMs.

Flank bruits due to giant renal arteriovenous malformation.

A 58-year-old woman was referred to the nephrology department because of a continuous bruit over the right flank heard by her primary care physician. Blood pressure was 120/80 mmHg. Complete blood count and urinary analysis were within normal limits. She had no history of prior renal surgery or trauma. A large cyst-like lesion at the right kidney with turbulent blood flow was found on colour Doppler ultrasound. Volume-rendered computed tomography (CT) angiography (Figure 1A) demonstrated giant cirsoid aneurysmal dilations of the right renal artery with early opacification of right renal vein (arrow) and inferior vena cava (arrowhead), indicating congenital renal arteriovenous malformations (AVMs). Therefore, right renal artery angiography (Figure 1B) confirmed the diagnosis of right giant renal AVMs by demonstrating cirsoid arterial communication with early visualization of the right renal vein (arrow) and inferior vena cava (arrowhead). At the same time, endovascular embolization of right AVMs was performed successfully with preservation of renal parenchymal vascular supply. The patient’s post-operative course was uneventful, and she was well 6 months later. Fig. 1 Volume-rendered computed tomography angiography (A) showing giant cirsoid aneurysmal dilations of right renal artery with early opacification of right renal vein (arrow) and inferior vena cava (arrowhead), indicating of congenital renal arteriovenous ... Renal AVMs are an uncommon disease of abnormal communications between intrarenal arterial and venous systems. These malformations can be congenital or acquired due to trauma, surgery and tumours. Acquired AVMs are often termed renal arteriovenous fistula. Congenital AVMs are a rare disease and account for 25% of renal AVMs [1]. Most congenital AVMs are asymptomatic. Symptomatic AVMs usually present with microscopic or gross haematuria, abdominal pain and flank bruit [2]. Renal Doppler sonography is a non-invasive tool that can help in distinguishing vascular lesions from cystic lesions based on a turbulent blood flow [3]. Renal CT angiography showed a typical appearance of cirsoid arterial communication with early visualization of inferior vena cava, indicating congenital arteriovenous malformations. Renal arteriography is still the gold standard modality which can help in a clearly visualization of abnormal vessels with early draining veins and the nidus of the AVM. Transcatheter embolization of renal AVMs can successfully obliterate the nidus of AVMs and preservation of renal normal parenchyma with reduced morbidity in comparison with surgical resection of renal AVMs [4]. Conflict of interest statement. None declared.

Nursing care of operation cooperation of arteriovenous malformation resection under neurological navigation

Objective To explore the application of neurological navigation in the resection of arteriovenous malformation (AVM) and introduce the way of operation cooperation for nurses.Methods Twentythree patients with AVMs underwent microsurgical under neurological navigation.The nursing experience of perioperative period was summarized.Results Total resection was achieved in all 23 cases under neurological navigation and no complications developed.Conclusions Besides of sufficient preparation and excellent professional skills,smooth cooperation by nurses trained with professional knowledge about neurological navigation system is vital of successful operation. Key words: Neurosurgery; Navigation system; Arteriovenous Malformation; Resection; Nursing

Spontaneous intracranial hemorrhage and obstructive hydrocephalus: unusual complications of a cervical intramedullary arteriovenous malformation

A case of acute severe noncommunicating hydrocephalus complicating a high cervical arteriovenous malformation (AVM) is presented here. A 29-year-old lady, 4 years after partial microsurgical resection of a high cervical intramedullary AVM, presented with sudden-onset weakness of all extremities, impaired cognition, cervical/occipital pains, and bisphincteric dysfunction. She was drowsy but arousable with a Glasgow coma scale score of 14. She had spastic quadriparesis and cognitive impairment. Cranial computerized tomographic scan showed marked panventriculomegaly. There was some blood residue in the posterior horn of the right lateral ventricle and transependymal spread of cerebrospinal fluid (CSF) indicative of the subacute/chronic nature of the obstruction to the CSF circulation. Cervical spine magnetic resonance imaging also showed the residual upper cervical AVM. She had an emergency ventriculoperitoneal shunting with good neurologic outcome. Spinal AVMs may present with unusual intracranial hemorrhagic complications. Attending physicians should always be mindful of this fact in the total clinical evaluations of each case.

Cavernous Angioma Associated With Arteriovenous Malformation of the Brain -Case Report-

A 61-year-old man presented a rare case of cerebral cavernous angioma associated with cerebral arteriovenous malformation (AVM) manifesting as headache. Magnetic resonance imaging showed an AVM in the right occipital lobe and a cavernous angioma in the left middle fossa. The patient underwent left frontotemporal craniotomy with total resection of the left parasellar intra-axial tumor. One month after the first operation, he underwent right occipital craniotomy with total resection of the right occipital AVM. The histological diagnoses were cavernous angioma and AVM, respectively. Immunostaining for angiogenic growth factors and structural proteins revealed different expression patterns of alpha-smooth muscle actin in these structures. Expression of structural proteins may reflect differences in their pathogenesis.

Multimodality treatment of cerebral AVMs in children: a single-centre 20 years experience

The purpose of this study was to review our experience with a multimodality treatment approach in the management of cerebral arteriovenous malformation (AVM) in children. We retrospectively analysed a consecutive series of 56 children who harboured a cerebral AVM and were treated at our institution between 1988 and 2008. During the whole treatment period, a combined treatment strategy, including microsurgery, endovascular treatment and gamma knife radiosurgery, was used. Of the 56 patients (median age, 14.0; range, 3 months-18 years) reported, 36 (64.3%) were admitted after AVM rupture; of these, only one AVM (1.8%) was considered untreatable. In 30.9% (17/55) of the treated patients, a single treatment measure was sufficient to attain angiographic cure of the AVM. Among these, six patients (10.9%) had microsurgical AVM resection, four patients (7.3%) underwent endovascular treatment, and another seven patients (12.7%) underwent radiosurgical management of the AVM. The majority of the population (38/55; 69.1%) underwent combined treatment: 21 patients (38.2%) received embolisation followed by radiosurgery of the remnant nidus, ten patients (18.2%) underwent embolisation with subsequent surgical resection of the residual AVM, three patients (5.5%) had radiosurgery after incomplete surgical AVM nidus resection and another four patients (7.3%) required a combination of all three treatment modalities to achieve permanent angiographic cure of the AVM. We observed good clinical outcomes (Glasgow Outcome Scale 5 and 4) in 94.6% of the children. Complete angiographic obliteration was achieved in 93.3% of the patients treated. A multimodality treatment approach in children harbouring cerebral AVMs leads to excellent angiographic and clinical outcomes.

Hypersexuality from resection of left occipital arteriovenous malformation

The authors report their experience on one patient with hypersexuality from resection of left occipital arteriovenous malformation. To the best of our knowledge, this is the first case reported in the literature. A 35-year-old right-handed female farmer suffered a sudden left occipital hemorrhage with subarachnoid and subdural hemorrhages of the left hemisphere. Transient left uncal herniation occurred at the onset and was released by conservative treatment. Digital subtraction angiography showed a brain left occipital arteriovenous malformation. After microsurgical resection of the arteriovenous malformation, the patient developed hypersexual behavior. Positron emission tomography showed hypermetabolism in the left frontal region and left posterior hippocampal gyrus and hypometabolism in the left anterior hippocampal gyrus and the left occipital surgical area. Theories concerning normal pressure perfusion breakthrough and specific areas in the brain responsible for the human sexual response are discussed.

PROSPECTIVE EVALUATION OF SURGICAL MICROSCOPE–INTEGRATED INTRAOPERATIVE NEAR-INFRARED INDOCYANINE GREEN ANGIOGRAPHY DURING CEREBRAL ARTERIOVENOUS MALFORMATION SURGERY

Microscope-integrated indocyanine green (ICG) fluorescence angiography is a novel technique in vascular neurosurgery with potential utility in treating arteriovenous malformations (AVMs). We analyzed the application of intraoperative ICG in 10 consecutive AVM surgeries for which surgical video was available. The ability to distinguish AVM vessels (draining veins, feeding and nidal arteries) from each other and from normal vessel was evaluated, and ICG angiographic findings were correlated with intra- and postoperative findings on digital subtraction angiography (DSA). ICG angiography was found to be useful by the surgeon in 9 of 10 patients. In 8 patients, it helped to distinguish AVM vessels. In 3 of 4 patients undergoing a postresection injection, it demonstrated that there was no residual arteriovenous shunting. In 1 patient, it helped to identify a small AVM nidus that was otherwise inapparent within a hematoma. Intraoperative DSA showed residual AVM in 2 of 10 patients requiring further resection of AVM not visualized during surgery. Microscope-integrated ICG angiography is a useful tool in AVM surgery. It can be used to distinguish AVM vessels from normal vessels and arteries from veins based on the timing of fluorescence with the dye. Our experience suggests that it is less useful with deep-seated lesions or when AVM vessels are not on the surface. ICG angiography complements rather than replaces DSA.