Angiographic disappearance of multiple dural arteriovenous malformations. Case report

Angiographic disappearance of two dural arteriovenous malformations (AVM's) in different locations in one case is reported. One of the AVM's involved the right transverse sinus, and the other involved the superior sagittal sinus. The patient's presenting symptoms were due to obstructive hydrocephalus resulting from a small intraventricular hemorrhage that was diagnosed by computerized tomography on admission. The symptoms cleared 25 hours after the ictus in conjunction with improvement of hydrocephalus. The AVM involving the right transverse sinus was supplied by the occipital artery, but ligation of that artery was not successful in eliminating the anomaly. One year later, follow-up angiography revealed disappearance of both dural AVM's.     

Relationship of perfusion pressure and size to risk of hemorrhage from arteriovenous malformations.

The relationship between the size of an arteriovenous malformation (AVM) and its propensity to hemorrhage is unclear. Although nidus volume increases geometrically with respect to AVM diameter, hemorrhages are at least as common, in small AVM's compared to large AVM's. The authors prospectively evaluated 92 AVM's for nidus size, hematoma size, and arterial feeding pressure to determine if these variables influence the tendency to hemorrhage. Small AVM's (diameter less than or equal to 3 cm) presented with hemorrhage significantly more often (p less than 0.001) than large AVM's (diameter greater than 6 cm), the incidence being 82% versus 21%. Intraoperative arterial pressures were recorded from the main feeding vessel(s) in 24 of the 92 patients in this series: 10 presented with hemorrhage and 14 presented with other neurological symptoms. In the AVM's that had hemorrhaged, the mean difference between mean arterial blood pressure and the feeding artery pressure was 6.5 mm Hg (range 2 to 15 mm Hg). In the AVM's that did not rupture, this difference was 40 mm Hg (range 17 to 63 mm Hg). Smaller AVM's had significantly higher feeding artery pressures (p less than 0.05) than did larger AVM's, and they were associated with large hemorrhages. It is suggested that differences in arterial feeding pressure may be responsible for the observed relationship between the size of AVM's and the frequency and severity of hemorrhage.     

Distal anterior choroidal artery aneurysm associated with an arteriovenous malformation. Intraoperative localization and treatment

BACKGROUND

Distal anterior choroidal artery aneurysms are rare. The outcome of patients with distal anterior choroidal artery aneurysms has been poor, and the treatment of such aneurysms is surgically challenging.

CASE DESCRIPTION

The authors describe the case of an 8-year-old girl with a ruptured distal anterior choroidal artery aneurysm associated with an arteriovenous malformation (AVM). The patient experienced sudden onset of headache and vomiting. Computed tomography revealed an intraventricular haemorrhage, and cerebral angiography demonstrated an aneurysm arising from the distal portion of the right anterior choroidal artery. The patient also had an AVM in the ipsilateral temporal lobe fed by the branches of the middle cerebral artery. A right frontotemporal craniotomy was performed with the aid of intraoperative angiography to eliminate both the AVM and the aneurysm. Intraoperative angiography was helpful in confirming the complete removal of the AVM and in accurate localization of the small and deeply placed distal anterior choroidal artery aneurysm. Both the AVM and the aneurysm were successfully treated and the patient was discharged without any neurological deficits.

CONCLUSION

This case is the youngest reported patient with a distal anterior choroidal artery aneurysm. This report is also the first to describe an association of such an aneurysm with an AVM. The etiology of the aneurysm formation in this case and surgical strategy for deeply placed vascular lesions are discussed.     

Embolization of arteriovenous malformations with peripheral aneurysms using ethylene vinyl alcohol copolymer. Report of three cases

The authors report three cases of arteriovenous malformations (AVM's) with aneurysms arising from the feeding artery; all were successfully treated with a new nonadhesive liquid embolic material, ethylene vinyl alcohol copolymer (EVAL). In two patients the AVM's were totally removed without difficulty, and in one the AVM was managed conservatively after embolization. No new neurological deficits appeared during or after embolization. After road-mapping techniques, EVAL was injected slowly until the feeding artery and aneurysm were completely obliterated. This embolic agent is easy to handle and is considered safe compared with other adhesive liquid embolic agents, such as isobutyl-2-cyanoacrylate or n-butyl cyanoacrylate. It is concluded that EVAL is an excellent agent for embolizing an AVM with a peripheral aneurysm on the feeding artery.     

Intra-arterial urokinase for treatment of retrograde thrombosis following resection of an arteriovenous malformation. Case report.

Retrograde thrombosis of feeding arteries is a potentially catastrophic complication occasionally reported following resection of arteriovenous malformations (AVM's). No successful therapy for this condition, which causes postoperative stroke, has previously been reported. A case of retrograde thrombosis of the left middle cerebral artery immediately following resection of a parietal AVM is reported in a patient with a retained intra-arterial catheter from preoperative embolization. The administration of urokinase within 4 hours of surgery resulted in dramatic clinical and angiographic improvement without hemorrhagic complications. While urokinase is considered highly experimental in this setting, this case demonstrates that thrombolytic agents should be viewed as therapeutic options worthy of further investigation.     

Intra-arterial embolization in the management of arteriovenous malformations.

Eighteen patients with arteriovenous malformations (AVM's) involving the extremities, pelvis, or head are reported and their treatment is discussed. Our experience has led us to the following conclusions: (1) careful selective angiography is mandatory to delineate the vascular anatomy, extent, and major afferent vessels supplying the AVM; (2) ligation of afferent vessels to an AVM never is indicated; (3) intra-arterial embolization (IAE) can be used prior to surgical removal of extensive but resectable AVM's; (4) IAE may be employed for symptom control of inoperable AVM's.     

Spinal arteriovenous malformations and neurogenic claudication. Report of two cases

Spinal arteriovenous malformations (AVM's) can present with symptoms of neurogenic claudication indistinguishable from those of lumbar spondylosis. Spinal AVM's occur most frequently in males of middle age or older; lumbar spondylosis is often also present in these patients. The myelographic appearance of the abnormal vessels may resemble that of the dilated veins or redundant nerve roots sometimes seen adjacent to regions of spinal block, obscuring the diagnosis. Two patients are described who presented with clinical histories and myelographic findings that led to laminectomies for presumed spinal stenosis; ultimately, both were found to have an AVM. Treatment of the AVM arrested the neurological decline in one patient, and resulted in dramatic improvement in the other. A hypothesis related to hemodynamic consequences of venous hypertension is presented in an attempt to link the pathophysiology of the two conditions.     

Use of balloon occlusion and substances to protect ischemic brain during resection of posterior fossa AVM. Case report

The successful resection of a large posterior fossa arteriovenous malformation (AVM) is reported. A balloon catheter was used for temporary intraoperative occlusion of the basilar artery and feeding vessels of the AVM. Prior to occlusion of these arteries, newly tested substances to protect the ischemic brain were administered to prolong occlusion time. Resection of the AVM was completed without complication, and the patient returned to normal life. This is a useful intraoperative procedure for the resection of AVM's considered inoperable by conventional approaches.     

Myelopathy due to intracranial dural arteriovenous fistulas draining intrathecally into spinal medullary veins. Report of three cases

Arteriovenous malformations (AVM's) of the spine commonly cause progressive myelopathy. Occasionally, myelography reveals serpentine filling defects characteristic of a spinal AVM, but an AVM or arteriovenous (AV) fistula cannot be demonstrated arteriographically, despite selective catheterization of all vessels known to have the potential of supplying the spinal cord and spinal dura. Often, and particularly in the setting of subacute or acute deterioration, this has been attributed to spontaneous thrombosis of the veins (the Foix-Alajouanine syndrome). Three patients are reported in whom intracranial dural AV fistulas, supplied by branches of the internal and external carotid arteries, drained into spinal veins and produced myelopathy. In one patient, motor and sensory deficits were limited to the lower extremities. In all three patients, disconnection of the fistula from its spinal venous drainage permitted arrest of a rapidly progressive myelopathy and partial recovery. These findings indicate that some patients who appear to have spinal cord AVM's but exhibit negative spinal arteriography are suffering from cranial dural AV fistulas and therefore need carotid as well as spinal arteriography. The considerable distance of these fistulas from the level of neurological expression supports venous hypertension as a pathophysiological mechanism of spinal cord injury. Interruption of a cranial dural fistula draining into spinal veins permits recovery of the myelopathy.     

The Nd:YAG laser in neurosurgery. Part 2. Clinical studies: an adjunctive measure for hemostasis in resection of arteriovenous malformations

The Nd:YAG laser has been used safely to aid in the resection of 10 cases of parenchymal arteriovenous malformations (AVM's). The laser was found helpful for: 1) defining the plane between the AVM and the brain; 2) coagulating any dural component of the AVM; and 3) achieving hemostasis of the bed following resection of the lesion. However, its overall benefit in the resection of AVM's remains to be determined, as it could not arrest active high-flow bleeding from the thin-walled vessels feeding the deep portion of the AVM. This was attributed to the inherent characteristics of these vessels, since the instrument has been effective in non-AVM arteries of similar dimensions containing contractile elements in the vessel walls. Future refinements in focusing instrumentation and operative technique should enhance its capabilities and usefulness. When used within the recommended power range, the Nd:YAG laser is safe and its penetration predictable. The fiberoptic cable light delivery system allows excellent mobility of the handpiece, but the protective eyewear laser-light filters reduce the available light to the surgeon. The instrument appears promising but more work is required.     

Management of dural arteriovenous malformations of the anterior cranial fossa

Eight patients with dural arteriovenous malformations (AVM's) of the anterior cranial fossa are presented, and the pertinent literature is reviewed. Unlike cases of dural AVM's in other locations, sudden massive intracerebral hemorrhage was the most frequent reason for presentation. Other symptoms included tinnitus, retro-orbital headache, and a generalized seizure. The malformations were supplied consistently by the anterior ethmoidal artery, usually in combination with other less prominent feeding vessels. The lesion's venous drainage was through the superior sagittal sinus via a cortical vein; in addition, in two cases a subfrontal vein drained the AVM. A venous aneurysm was encountered near the site of anastomosis with the dural feeder in most cases, and was found in all patients who presented with hemorrhage. The AVM was obliterated surgically in six patients, with favorable results achieved in five. One patient died postoperatively from a pulmonary complication. Because of their anatomy and proclivity for hemorrhage, these vascular malformations represent a unique group of dural AVM's. Surgical management of anterior fossa dural AVM's carries low morbidity, and is indicated when the lesions have caused hemorrhage or when there is an associated venous aneurysm.     

Dural arteriovenous malformations of the spine. Clinical features and surgical results in 55 cases

The clinical and angiographic findings of 55 patients with a spinal dural arteriovenous malformation (AVM) are reviewed, and the results of surgery assessed. The symptoms of dural AVM are usually gradual in onset, and hemorrhage from this type of AVM is less common than in true spinal cord angiomas. Other clinical features and the myelographic findings are similar to those of spinal cord angiomas. On angiography, the nidus of dural AVM's usually projected lateral to the spinal cord. Clipping of communicating vessels between the AVM and the coronal plexus was carried out in 50 patients, and decompressive laminectomy only in five cases. Surgery led to improvement of disturbed gait or arrest of a previously progressive course in 85% of those managed by clipping communicating vessels. The pathophysiology and surgical treatment of dural AVM's are discussed.     

The Treatment of dural AVM by embolization with aron alpha (Ethyl-2-cyanoacrylate)

The authors report four cases of dural arteriovenous malformation (AVM) treated by a modified technique of embolization. Three cases had posterior fossa dural AVM and one had bilateral supratentorial dural AVM. The authors think that the best way to treat dural AVM is to close its nidus completely. This could be achieved by a safe and easy technique of embolization. The material used for embolization should intimately adhere to the vascular network and should not become fragmented. We used aron alpha (Ethyl-2-cyanoacrylate). This is a biological glue and it sets in a solid membranous form instantaneously on coming into the contact with an ionic medium. It does not get fragmented. Aron alpha was injected into the nidus of the AVM through a cannula inserted only into the main feeding artery in four cases of dural AVM reported here. Postoperative angiography showed complete obliteration of the AVM's, they did not fill either from the treated artery or from the untreated feeding arteries. The technique is easy and safe. There was no operative or postoperative complication. All the patients have remained asymptomatic to date, i.e. 2, 2, 6 and 7 1/2 years after the procedure.     

Morphological studies of human arteriovenous malformations. Effects of isobutyl 2-cyanoacrylate embolization

Ten patients with symptomatic arteriovenous malformations (AVM's) underwent embolization with isobutyl 2-cyanoacrylate (Bucrylate) delivered via a mini-balloon catheter according to the protocol of George and Pevsner. These patients underwent surgical removal of their embolized AVM, and surgical specimens were evaluated by light and scanning electron microscopy. Ten other patients with AVM's underwent surgical resection without prior embolization, and these surgical specimens were evaluated in a similar manner. Results from this study indicate that Bucrylate incites an inflammatory response characterized by foreign-body giant cells. This reaction was present as early as 3 weeks after embolization and persisted in specimens resected almost 1 year after the last embolization. No such reaction was observed in unembolized AVM's. Both light and scanning electron microscopy demonstrated a lattice structure of the Bucrylate embolus within the AVM vessels. These studies also demonstrated micro-channels within the Bucrylate embolus and the presence of what appears to be normal red blood cells within the latticework of the embolus. Vascular endothelium not in direct contact with the Bucrylate embolus retains a normal morphology as revealed by scanning electron microscopy.     

Arteriovenous malformation associated with moyamoya disease--case report.

The authors report a case of moyamoya disease accompanied by arteriovenous malformation (AVM). Angiography demonstrated typical moyamoya vessels on the right and early changes of moyamoya disease on the left. A small AVM in the left frontal lobe supplied by a distal branch of the middle cerebral artery (MCA) was also revealed. The AVM was surgically resected simultaneously with contralateral encephaloaponeurotic synangiosis for the moyamoya vessels. One month after surgery, left MCA occlusion at the origin occurred probably due to hemodynamic changes after the resection of the AVM.     

Unruptured intracranial aneurysms and arteriovenous malformations: frequency of intracranial hemorrhage and relationship of lesions

Among 91 patients with unruptured intracranial arteriovenous malformations (AVM's), 16 patients had 26 unruptured intracranial saccular aneurysms. An actuarial analysis showed the risk of intracranial hemorrhage among patients with coexisting aneurysm and AVM to be 7% per year at 5 years following diagnosis compared to 1.7% for patients with AVM alone. The difference in length of survival free of hemorrhage was significant (log-rank, p less than 0.0007). Several angiographic and clinical parameters were investigated to better understand the relationship of these lesions. The aneurysms occurred in similar percentages in patients with small, medium, and large AVM's. Twenty-five aneurysms were on arteries feeding the malformation system, almost equally distributed proximally and distally. Eleven aneurysms were atypical in location, and all arose from primary or secondary branch feeders to the malformation; 24 were on enlarged feeding arteries. Eleven (16%) of the 67 patients with high-flow AVM's had associated aneurysms, compared with five (21%) of the 24 patients with low-flow AVM's. Four (16%) of 25 low-shunt malformations and 12 (18%) of 65 high-shunt malformations had associated aneurysms. All five aneurysms associated with low-shunt malformations were on a direct arterial feeder of the malformation. These data suggest that the intracranial AVM's predispose to aneurysm formation within AVM feeding systems and that the mechanism is not simply based upon the high blood flow or high arteriovenous shunt in these systems.     

Evaluation of cerebral AVM's using transcranial Doppler ultrasound

Blood flow velocities in basal cerebral arteries were recorded noninvasively in 28 patients with cerebral arteriovenous malformations (AVM's) and were correlated with the angiographic findings. In normal arteries remote from the AVM, flow velocities ranged from 44 to 94 cm/sec (median 65 cm/sec) with pulsatility indexes from 0.65 to 1.10 (median 0.87). This is consistent with findings in normal individuals. Arteries feeding the AVM's were identified by the high flow velocities (ranging from 75 to 237 cm/sec, median 124 cm/sec). The pulsatility index ranged from 0.22 to 0.74 (median 0.48). The difference of these results from findings in normal remote arteries was highly significant (p less than 0.001). Hyperventilation tests illustrated the hemodynamic difference between an AVM and normal cerebrovascular beds. Flow velocity measurements permitted noninvasive diagnosis of AVM's in 26 of the 28 patients. Furthermore, the identification of individual feeding arteries permitted good definition of the anatomical localization of individual AVM's. Flow velocity measurements combined with computerized tomography scans are useful in the diagnosis of AVM's. With the feeding artery's configuration identified on angiography, flow velocity measurements permit a new insight into the "hemodynamic dimension" of an AVM and its possible effects on adjacent normal brain-tissue perfusion in the individual patient.     

A case report of arteriovenous malformation of the tongue: vascular anatomy and note for transarterial embolization

Arteriovenous malformation (AVM) of the tongue is a rare lesion of the cranio-facial vascular anomaly. Decision making concerning the vascular anomaly is not established because there are complex classifications of diagnosis and many treatment options. We report a case of AVM of the tongue, and review vascular anatomy and knowledge for treating this lesion. A 50-year-old man presented with dysarthria, sleep apnea and snoring because of a mass lesion of his sublingual region that had become larger over a two-year period. Neuroradiological examination revealed lingual arteriovenous fistula (AVF) associated with AVM of the tongue base. We performed transfemoral transarterial embolization via both lingual arteries using Polyvinyl alcohol particles and Eudragit-E as non-adhesive glue material. Final angiograms after embolization revealed a small residual nidus fed by the right facial artery mental branch, but shunt flow was markedly reduced. This vascular malformation was removed after a day of TAE (transarterial embolization). The patients symptom was improved and relapse has not been confirmed though 18 months have passed since the surgery. Using classification proposed by Mulliken and Glowacki, vascular anomalies are divided into two groups: hemangiomas and vascular malformations (AVM/F, arterial, venous, capillary, lymphatic and combined). AVM/F is classified into high flow malformation. TAE is useful for high flow malformation and can be used as the sole treatment or as an adjunct. Treatment should be to eradicate nidus or fistula completely, which is the fundamental abnormality because even the smallest residual nidus will expand to cause recurrence. The treatment of Cranio-facial AVM's requires rigorous differential diagnosis and appropriate management. Inadequate treatment is thought to contribute to collateral flow and disease progression in advanced AVM, making further management difficult.     

Familial arteriovenous malformations. Report of four cases in one family

Familial arteriovenous malformations (AVM's) are uncommon entities, with only seven reported cases in the English literature. Some have been associated with hereditary telangiectasia. A family in which AVM's were found in four male members of two generations is reported. In addition, one patient had a large cyst associated with his AVM without previous evidence of acute hemorrhage, which is an uncommon presentation. The family is discussed and a brief review of the literature is presented.     

Multiple dural arteriovenous malformations. Report of two cases

Two cases of multiple dural arteriovenous malformations (AVM's) in different locations are reported. One patient was diagnosed as having a dural AVM involving the right cavernous sinus that disappeared spontaneously 4 months after onset of symptoms. After an interval of 4 months, another dural AVM appeared involving the right lateral sinuses (transverse and sigmoid sinuses) with occlusion of the right sigmoid sinus. In the other patient, multiple dural AVM's were demonstrated on angiography, one involving the cavernous sinus and the other the left lateral sinus. The frequency of multiple occurrence and possible mechanisms of sinus occlusion are discussed.