Pressure variations in cerebral venous sinuses of idiopathic intracranial hypertension patients

Abstract

Purpose: To evaluate the alteration of pressure characteristics in the cerebral venous sinuses before and after venous sinus stenting (VSS) using mean sinus pressures (MSPs), sinus pressure gradient (SPG), and sinus pressure pulsatility (SPP) parameters among the idiopathic intracranial hypertension (IIH) patients.

Materials and methods: Prospective evaluation of 45 consecutive IIH patients who underwent VSS at our institution. A written informed consent approved by the Weill Cornell Institutional Review Board was signed by the study participants. All patients (n = 45) were evaluated for MSPs and SPG. In a subgroup of 12 (n = 12) consecutive patients, SPP was measured. MSP was measured using microcatheter at superior sagittal sinus (SSS), transverse sinus (TS), and sigmoid sinus (SS). SPG was measured as trans-stenotic gradient and trans-torcular gradient. SPP was recorded in the dominant TS with a six French intermediate catheter. Statistical analysis was performed using paired student t-test and two sample t-tests tested for both equal and unequal variances. P values below 0.05 were considered significant.

Results: The mean age of the study population was 30.6 ± 10 years (7-59 years) and 43 out of 45 are female patients. The mean weight and BMI of the study population were 96 ± 24.7 kg (30.8-144 kg) and 35.6 ± 8.3 kg/M² (16.4-51.4 kg/M²), respectively. VSS in IIH patients resulted in immediate reduction of MSP in the SSS {Δ Mean: -8.1 mm Hg [95% confidence interval (CI): -5.0-11.7 mm Hg], p < 0.001} and TS [Δ Mean: -11.8 mm Hg (95% CI: -7.5 to 13.4 mm Hg), p < 0.001] and increase of MSP in SS [Δ Mean: 7.5 mm Hg (95% CI: 6-10.1 mm Hg), p < 0.001]. Significant reduction of trans-stenotic SPG reduction [Δ Mean: -15.7 mm Hg (95% CI: -13.6-17.8 mm Hg), p < 0.001] and SPP [Δ Mean: -8 mm Hg (95% CI: -2.5-13.4 mm Hg), p < 0.05] was observed following VSS.

Conclusion: VSS resulted in immediate alteration of the cerebral venous sinus pressure measurements in patients with IIH.

Figure 1. Frontal (top row) and latera (middle row) projections demonstrating the microcatheter position (white arrow) in the SSS, TS, and SS. Sinus pressure curves and MSP values at each location are shown in the bottom row.

Figure 2. SPP recording using a six French intermediate catheter in dominant mid-TS before and after VSS. Note the reduced sinus pulsatility on post-stent recording compared to pre-stent recording (notice the variation in the scale between two recordings). The mean venous pressure and VPP were calculated from sinus pulsatility recordings.

Figure 3. The systemic parameters are documented at the time of SPP recording before and after the venous sinus stent to avoid bias from a systemic parameter.