2026 Proffered Presentations
S241: CRITICAL BOTTLENECKS IN CRANIOCERVICAL VENOUS OUTFLOW: INSIGHTS FROM A MULTISITE REVIEW AND COHORT ANALYSIS
Alisha E Suri, BSc1; Trevor H Torigoe, PhD1; Ferdinand K Hui2; Edward J Hepworth3; 1John A. Burns School of Medicine; 2The Queen's Health Systems; 3Denver Sinus Care
Background: Intracranial venous insufficiency stems from impaired drainage through dural venous sinuses and extracranial outflow tracts. Transitional zones, such as those between the superior sagittal (SSS), straight (SS), and brachiocephalic system are key sites of resistance but remain poorly defined, hindering management. This study is among the first to integrate multisite review, cohort analysis, and representative cases to delineate venous stenosis patterns and their clinical significance.
Methods: We conducted a multisite review of anatomic, radiographic, and hemodynamic studies to evaluate resistance points along the dural venous pathway. In parallel, 55 patients presenting with extracranial venous outflow obstruction were analyzed to determine the prevalence and distribution of stenosis.
Results: Venous outflow impairment commonly reflected turbulent flow at sinus confluences, junctional stenosis, and extrinsic compression at the thoracic inlet. In the 55-patient cohort, frequent sites of internal jugular vein (IJV) stenosis included the level of styloid/C1 (S/C1) (100%), carotid bulb (85.5%), transverse sinus (67.3%), torcular Herophili (49.1%), brachiocephalic vein (38.9%), sigmoid sinus (32.7%), jugular foramen (27.3%), hyoid-omohyoid (27%) segment, and omohyoid-clavicle (23.6%) segment.
In a representative case, a 43-year-old female with Ehlers-Danlos syndrome presented with postural headaches, dizziness, and visual obscurations. Studies showed IJV compression at S/C1 and narrowing at C5-6 from the sternocleidomastoid (SCM) muscle with a brain-heart gradient of 10mmHg. Bilateral styloidectomy improved IJV patency but symptoms recurred. Repeat venography revealed residual intracranial gradients (8mmHg at SSS and SS), which fell to 3 and 2mmHg after stenting with clinical improvement. This case (Figures 1 & 2) highlights the interplay of extracranial and intracranial resistance and the value of combined decompression and stenting.
Figure 1: Head and neck venogram showing pre- (A-H) and post-styloidectomy (I-P) IJV outflow. Both IJVs exhibited compression at S/C1 (red arrow) and C5-6/SCM (blue arrow). (A-D) Right IJV: neutral flow with collaterals (C, black arrow) and increased collateral flow on flexion (D). (E-H) Left IJV: neutral compression at S/C1 and C5-6/SCM, with worsened compression and collateral flow on flexion. Post-styloidectomy right IJV: improved S/C1 flow with residual C5-6/SCM compression with no collaterals in both neutral (I-J) and flexion (K-L) positions. Post-styloidectomy left IJV: improved S/C1 patency with residual C5-6/SCM compression; in both neutral (M-N) and flexion (O-P) positions.
Figure 2: Cerebral venography of intracranial venous drainage. (A-C) Post-styloidectomy venograms show SSS (A, B) and SS (C) compression (red arrows) with collateral vessels (black arrows). SSS patency improves after Precise stent placement (D, E). SS patency improves after LVIS stent placement (F).
Conclusion: Junctions along the venous outflow pathway are key bottlenecks for venous insufficiency. Recognizing high-prevalence sites such as the IJV, transverse and sigmoid sinuses, torcular Herophili, and brachiocephalic vein is crucial for diagnosis and treatment. This study highlights how multisite analysis and illustrative cases can clarify venous outflow obstruction, underscoring the need for further work to refine imaging and assess targeted interventions.