Among the 143 DAVF patients, 46(32.2%) were female and 97(67.8%) were male. Patients’ age ranged from 5 to 74 years (mean, 46 ± 15 years). Aggressive symptoms (cranial nerve symptom, venous sinus hypertension and intracranial hemorrhage) were present in 124 (86.7%) patients. The distributions of DAVFs were cavernous sinus in 40(28.0%) patients, transverse-sigmoid sinus in 39(27.3%) patients, tentorium in 30(21.0%) patients, anterior cranial fossa in 11(7.7%) patients, sagittal sinus in 9(6.3%) patients, occipital foramen or clivus in 4(2.8%) patients and spine in 9(6.3%) patients. Venous drainage was type 1 in 9(6.3%) patients, type 2 in 66(46.2%) patients and type 3 in 68(47.5%) patients according to modified Borden classification. Twenty-three patients were not treated and 120 patients were treated by transarterial embolization(TAE) in 86 patients, transvenous embolization(TVE) in 22 patients, a combination of two modalities in 3 patients, open surgery in 2 patients and radiosurgery in 7 patients. The overall cure rate was 70% (84/120) and with 30%(36/120) resulted in partial embolization. Favorable clinical outcome was presented in 127 (88.8%) patients and unfavorable clinical outcome was presented in 16 (11.2%) patients at follow-up.(Table 2)
Table 2
Symptoms and locations of DAVFs in 143 patients.
|
TypeI(n = 9)
|
TypeII(n = 65)
|
TypeIII(n = 68)
|
Symptoms
|
|
|
|
Incidental
|
3
|
2
|
5
|
Pusatile tinnitus
|
5
|
5
|
3
|
Cranial nerve symptom
|
0
|
4
|
|
Venous sinus hypertentiom
|
0
|
59
|
32
|
Hemorrhage
|
0
|
0
|
24
|
Locations
|
|
|
|
Cavernous sinus
|
3
|
36
|
1
|
Transverse-sigmoid sinus
|
2
|
23
|
14
|
Sagittal sinus
|
2
|
4
|
3
|
Anterior cranial fossa
|
1
|
1
|
9
|
Tentorium
|
0
|
0
|
30
|
Occipital foramen or clivus
|
0
|
1
|
3
|
Spine
|
0
|
1
|
8
|
Type I
Nonaggressive symptoms (asymptomatic and pulsatile tinnitus) were present in 6/9 patients. However, cranial nerve symptom was present in 2 patients and sinus hypertension in 1 patient. The locations of Type I DAVFs were 3 cavernous sinus, 2 transverse sinus, 2 superior sagittal sinus and 1 anterior cranial fossa. Five patients were not treated, 3 patients were treated by TAE and 1 was treated by TVE to relieve tinnitus symptoms(Fig. 1). Three patients resulted in cure embolization with 1 partial embolization. All 9 patients were favorable in clinical outcome at follow-up.
Type II
In the 66 patients with type II drainage, nonaggressive symptoms were present in 7 patients and aggressive symptoms (cranial nerve symptom and venous sinus hypertension without intracranial hemorrhage) in 59 (89.4%) patients. DAVFs of type II were located: 36 cavernous sinus, 23 transverse sinus, 4 superior sagittal sinus, 1 anterior cranial fossa, 1 occipital foramen and 1 spine. Eleven patients were not treated and 55 patients were treated by TAE in 29 patients(Fig. 2), TVE in 19 patients, a combination of two modalities in 2 patients, and radiosurgery in 1 patient. There was no open surgery performed for type II DAVFs. The overall cure rate was 67.3% (37/55) and with 32.7%(18/55) resulted in partial embolization. Favorable clinical outcome was presented in 61 (92.4%) patients and unfavorable clinical outcome was presented in 5 (7.6%) patients at follow-up.
Type III
Sixty-eight patients had type 3 DAVFs. Fifty-nine (86.8%) had aggressive symptoms (cranial nerve symptom, venous sinus hypertension and intracranial hemorrhage) and nonaggressive symptoms in 9 (13.2%) patients. DAVFs of type III were 30 tentorium(Fig. 3), 1 cavernous sinus, 14 transverse sinus, 3 superior sagittal sinus, 9 anterior cranial fossa, 3 occipital foramen or clivus and 8 spine(Fig. 4). Seven patients were not treated and 61 patients were treated by TAE in 53 patients, TVE in 3 patients, a combination of two modalities in 1 patients, open surgery in 2 patients and radiosurgery in 2 patients. The overall cure rate was 72.1% (44/61) and with 27.3%(17/61) resulted in partial embolization. Favorable clinical outcome was presented in 57 (83.8%) patients and unfavorable clinical outcome was presented in 11 (16.2%) patients at follow-up.
Statistical analysis results
No correlation was observed between age and modified Borden types(p = 0.782). There was a male predominance of 67.8% in our patients and a correlation was observed between male and type III DAVF(p < 0.001). Location of the DAVF was statistically significantly correlated with the DAVF types (p < 0.001). In our series, type III was associated with non-sinus and spinal DAVFs but type I and II were associated with sinus DAVFs. More than 3 pedical suppliers and pial arterial suppliers were associated with high grade (type II and III) DAVFs(p = 0.003). Worse symptoms were present in most type II and type III patients(p < 0.001). However, intracranial hemorrhage was only presented in type III patients (35.3%). There was no difference in complication rate between 3 DAVF types(p = 0.934). Type III DAVF was associated with TAE and type II DAVF was associated with TVE treatment modalities(p < 0.001). There was no difference in complete obliteration rate between 3 DAVF types(p = 0.094).(Table 3)
Table 3
Statistical analysis of DAVF characteristics, treatment and outcome between 3 modified Borden types.
Characteristics
|
Value
|
Type I
(n = 9)
|
Type II
(n = 66)
|
Type III
(n = 68)
|
P-value1
|
Age
|
Years, mean ± SD
|
43 ± 17
|
47 ± 16
|
46 ± 13
|
0.782
|
Sex
|
Female
|
4
|
32
|
10
|
< 0.001
|
|
Male
|
5
|
34
|
58
|
|
Location
|
Sinus
|
7
|
63
|
18
|
< 0.001
|
|
Non-sinus
|
2
|
2
|
42
|
|
|
Spinal
|
0
|
1
|
8
|
|
Supplier
|
ECA,internal costal
|
4
|
12
|
21
|
0.003
|
|
ECA,ICA
|
1
|
37
|
20
|
|
|
ICA,VA
|
2
|
4
|
5
|
|
|
ICA
|
2
|
2
|
9
|
|
|
ECA,ICA,VA
|
0
|
6
|
1
|
|
|
ECA,ICA,VA,pial
|
0
|
2
|
0
|
|
|
ECA,ICA,pial
|
0
|
1
|
6
|
|
|
ECA,pial
|
0
|
2
|
2
|
|
|
VA
|
0
|
0
|
1
|
|
|
VA,pial
|
0
|
0
|
1
|
|
|
Pial
|
0
|
0
|
2
|
|
Presentation
|
benign
|
9
|
7
|
12
|
< 0.001
|
|
Worse
|
0
|
59
|
56
|
|
Complication
|
Yes
No
|
1
8
|
10
56
|
12
56
|
0.934
|
Treatment
|
TAE
|
3
|
29
|
53
|
< 0.001
|
|
TVE
|
1
|
19
|
3
|
|
|
TAE + TVE
|
0
|
2
|
1
|
|
|
Radio, surgical
|
0
|
5
|
4
|
|
|
Untreated
|
5
|
11
|
7
|
|
Result
|
Complete
|
3
|
37
|
44
|
0.094
|
|
Subtotal
|
1
|
2
|
5
|
|
|
Partial
|
1
|
17
|
12
|
|
|
Untreated
|
4
|
10
|
7
|
|
Post-mRS
|
Score, mean ± SD
|
0.67 ± 0.5
|
0.65 ± 0.83
|
1.16 ± 1.89
|
0.109
|
1 The p-values are computed from Fisher exact tests (for categorical variables) and one-way ANOVA (for continuous variables). Bold indicates significant differences (p < 0.05) within three modified Borden types in terms of the corresponding variable. ECA, dural branches of external carotid artery; ICA, dural branches of internal carotid artery; VA, dural branches of vertebral artery; TAE, transarterial embolization; TVE, transvenous embolization; mRS, modified Rankin Score scale.
|
The results of one-way ANOVA indicated that pre-mRS was significantly different within modified Borden types and Cognard types (p = 4.3 x 10− 6 and p = 1 x 10− 4, respectively) but not significantly different within Borden types (p = 0.24). The means (standard errors) of pre-mRS of modified Borden types are 0.78 (0.67), 2.24 (0.75), and 2.35 (0.97) in turn. The means (standard errors) of pre-mRS of Borden types are 2.07 (0.83), 2.1 (0.96), and 2.34 (0.98) in turn. The means (standard errors) of pre-mRS of Cognard types are 0.78 (0.67), 2.22 (0.69), 2.29 (0.92), 2.41 (1), 2.18 (1.02), and 3 (0) in turn. Apparently, in terms of pre-mRS, patients were not separated well using Borden grading system(Fig. 5).
We further compare the modified Borden grading system and the Cognard grading system. The violin plots in Fig. 5 demonstrated that the patterns of the distributions of pre-mRS for 3 grading systems were very different. For different modified Borden types, the pre-mRS concentrated in values of 1, 2, and 3, respectively, and there is very little overlap between the three distributions. In contrast, pre-mRS is not highly distinguishable for different Cognard types, and there is considerable overlap. Nine spinal DAVF patients did not fall into any of the Cognard types (i.e. ''none'' in Fig. 5). Moreover, the modified Borden grading system was simple since it only had 3 types, while there were 5 types in the Cognard grading system. Pre-mRS was monotonous in the modified Borden grading system but was not in the Cognard grading system. Therefore, the modified Borden grading system was more informative than Cognard's by providing an effective assessment for the risk of patients with simple but precise results.