The validity of classification for the clinical presentation of intracranial dural arteriovenous fistulas

Abstract

A number of classification schemes for intracranial dural arteriovenous fistulas (AVFs) have been published that claim to predict which lesions will present in a benign or aggressive fashion based on radiological anatomy. We have tested the validity of two proposed classification schemes for the first time in a large single-institution study. A series of 102 intracranial dural AVFs in 98 patients assessed at a single institution was analyzed. All patients were classified according to two grading scales: the more descriptive schema of Cognard, et al. (Cognard) and that recently proposed by Borden, et al. (Borden). According to the Borden classification, 55 patients were Type I, 18 Type II, and 29 Type III. Using the Cognard classification, 40 patients were Type I, 15 Type IIA, eight Type IIB, 10 Type IIA+B, 13 Type III, 12 Type IV, and four Type V. Intracranial hemorrhage (ICH) or nonhemorrhagic neurological deficit was considered an aggressive presenting clinical feature. A total of 16 (16%) of 102 intracranial dural AVFs presented with hemorrhage. Eleven of these hemorrhages (69%) occurred in either anterior cranial fossa or tentorial lesions. When analyzed according to the Borden classification, none (0%) of 55 Type I intracranial dural AVFs, two (11%) of 18 Type II, and 14 (48%) of 29 Type III intracranial dural AVFs presented with hemorrhage (p < 0.0001). After exclusion of visual or cranial nerve deficits that were clearly related to cavernous sinus intracranial dural AVFs, nonhemorrhagic neurological deficits were a feature of presentation in one (2%) of 55 Type I, five (28%) of 18 Type II, and nine (31%) of 29 Type III patients (p < 0.0001). When combined, an aggressive clinical presentation (ICH or nonhemorrhagic neurological deficit) was seen most commonly in intracranial dural AVFs located in the tentorium (11 (79%) of 14) and the anterior cranial fossa (three (75%) of four), but this simply reflected the number of higher grade lesions in these locations. Aggressive clinical presentation strongly correlated with Borden types: one (2%) of 55 Type I, seven (39%) of 18 Type II, and 23 (79%) of 29 Type III patients (p < 0.0001). A similar correlation with aggressive presentation was seen with the Cognard classification: none (0%) of 40 Type I, one (7%) of 15 Type IIA, three (38%) of eight Type IIB, four (40%) of 10 Type IIA+B, nine (69%) of 13 Type III, 10 (83%) of 12 Type IV, and four (100%) of four Type V (p < 0.0001). No location is immune from harboring lesions capable of an aggressive presentation. Location itself only raises the index of suspicion for dangerous venous anatomy in some intracranial dural AVFs. The configuration of venous anatomy as reflected by both the Cognard and Borden classifications strongly predicts intracranial dural AVFs that will present with ICH or nonhemorrhagic neurological deficit.

Stereotactic radiosurgery for intracranial dural arteriovenous fistulas: a systematic review

“…Thus, these highrisk DAVFs usually warrant more immediate treatments in which modalities such as endovascular embolization and microsurgical ligation are used. 9 As reflected in our results, fewer Borden Types II and III DAVFs were treated using SRS than Type I lesions. In the largest series of NCS DAVFs treated using SRS, Pan et al observed a similar trend.…”

“…1,21 To better characterize DAVF hemorrhagic risk, the Borden and Cognard classification systems are used. 5,8,9 Borden Types II and III and Cognard Types IIb-V DAVFs confer significantly higher risks of hemorrhage than Borden Type I and Cognard Types I and IIa DAVFs. Thus, these highrisk DAVFs usually warrant more immediate treatments in which modalities such as endovascular embolization and microsurgical ligation are used.…”

Progressive versus Nonprogressive Intracranial Dural Arteriovenous Fistulas: Characteristics and Outcomes

“…Of course, the most complex lesions with CVD were not curable with embolization, surgery, or radiosurgery and thus did persist to show progression on follow-up. Cortical venous drainage is a well-established risk factor for aggressive clinical presentation 15,16,36,37 and is related to poor clinical outcome in untreated lesions: Venous hypertension can lead to not only cortical edema and seizures but, more seriously, vein rupture and intracranial hemorrhage. 38 Few studies to date have explored the prognostic significance of CVD in the setting of definitive management.…”

Central Nervous System Vascular Malformations

“…Possible precipitating factors such as trauma, tumour, cerebral thrombophlebitis, neurological surgery, or ENT infection, can be demonstrated in 15-32% of cases [106][107][108][109]. By including patients with generalised hypercoagulable states (such as peripheral DVT, pregnancy, and use of oral contraceptive pill), a large meta-analysis reported that 66% of DAVMs had some possible predisposing factor [110].…”

“…Subsequently, more detailed studies have demonstrated that after accounting for the pattern of venous drainage, location has no direct correlation with the behavior or natural history of a particular lesion [106,107,134]. Instead, due to local venous anatomy, DAVMs in some locations (such as the ACF and tentorial incisura) are more likely to develop retrograde parenchymal venous drainage; it is this pattern of venous drainage that has been demonstrated to be predictive of aggressive behavior [106,107,[159][160][161].…”