The Effects of Pressure Gradient on Papilledema Improvement After Venous Sinus Stenting in Idiopathic Intracranial Hypertension

Purpose: This study aimed to evaluate the impact of the pressure gradient on papilledema after stenting in patients with idiopathic intracranial hypertension (IIH) patients and venous sinus stenosis (VSS).Materials and Methods: In this prospective cohort study, we examined 121 patients with IIH and VSS who underwent stenting. The papilledema Frisen grade at the 1-month follow-up was used as a grouping factor (favorable outcome: 0-1; unfavorable outcome: 2-5). We used multivariable logistic regression modeling to determine independent predictors of favorable outcome. The performance of the prediction model was evaluated using a receiver operating characteristic (ROC) analysis.Results: A total of 96 patients had papilledema grades 0 to 1, and 25 patients had papilledema grades 2 to 5. Patients with the first group had significantly lower gradient pressures preoperatively (15.2 mmHg vs. 21.4 mmHg, p=0.001) and postoperatively (2 mmHg vs. 3.3 mmHg, p=0.002) relative to those in the second group. Multivariate analysis indicated that preoperative pressure gradient (odds ratio [OR] = 1.119; 95% confidence interval [CI] = 1.034-1.211]) and postoperative pressure gradient (OR = 1.498; 95% CI = 1.147-1.957) were independent predictors of favorable outcome. In the ROC analysis, the cut-off pressure gradient for the highest sensitivity (0.44) and specificity (0.874) was 22.75 mmHg, with a Youden's index of 0.314. Survival analysis demonstrated that patients with a preoperative pressure gradient <22.75 mmHg had more rapid improvement of papilledema than did those with a pressure gradient >22.75 mmHg (mean+SD: 2.639+0.382 [95% CI: 1.890-3.388] versus mean+SD: 3.882+0.884 [95% CI: 2.149-5.616]; p=0.004).Conclusion: A significant reduction in the pressure gradient appears to be strongly correlated with the success of VSS in patients with IIH. A higher preoperative pressure gradient may reduce stenting efficacy in patients with IIH.