2025 Poster Presentations
P249: ANGIOGRAPHIC RISK FACTORS FOR MISLATERALIZATION WITH INFERIOR PETROSAL SINUS SAMPLING IN CUSHING'S DISEASE
Nicole M De La Pena, MD; Michael Martini, MD, PhD; R. Chase Ransom, MD, PhD; Ramin Morshed, MD; Derek O'Keeffe, MD, PhD; William Young Jr., MD; John Atkinson, MD; Lorenzo Rinaldo, MD, PhD; Harry Cloft, MD, PhD; Jamie Van Gompel, MD; Mayo Clinic Hospital
Introduction: In MRI-negative Cushing’s disease, inferior petrosal sinus sampling (IPSS) can help confirm the pituitary as the source of excess ACTH. Prior studies have demonstrated that IPSS does not correlate with pituitary adenoma laterality; however, IPSS-guided resection continues to be practiced. This study evaluated different patterns of angiographic cross filling of IPSS venograms to categorize the risk of pituitary adenoma mislateralization.
Methods: A single center, retrospective review of cases between 1998-2017 was performed in which patients underwent IPSS for a presumed ACTH-secreting pituitary adenoma with negative/equivocal imaging. IPSS venograms were evaluated for angiographic cross filling into the contralateral IPS and the presence of basilar venous plexus filling along the clivus. Angiographic filling patterns were subdivided into three groups (Fig. 1): Group 1: no angiographic cross filling when either IPS was injected; Group 2: angiographic cross filling that occurred with the injection of one IPS but not the other (directional cross filling); Group 3: angiographic cross filling that occurred when either IPS was injected (bilateral cross filling). The contralateral and ipsilateral ACTH response ratios (ratio of change in ACTH levels measured at 10 minutes compared to 2 minutes after CRH administration) were compared between each group. The rate of agreement between IPSS lateralization and intraoperative lateralization was calculated. A multivariate logistic regression was performed with multiple venogram characteristics to create a model of factors that predicts an increased risk of mislateralization by IPSS.
Results: Forty-two patients were included in the study, with 9 patients classified in group 1 (21.4%), 17 in group 2 (40.5%), and 16 in group 3 (38.1%). The mean fold increase of ACTH levels in the ipsilateral or contralateral IPS was not significantly different between groups; however, there was a trend of increasing contralateral and decreasing ipsilateral ACTH response ratio from group 1 to group 3 (Fig. 2). Patients in group 1 and group 2 had a 77.8% and 94.1% rate of agreement between IPSS and intraoperative lateralization, respectively, while patients in group 3 only had a 68.8% rate of agreement. Multivariate analysis revealed that bilateral cross filling had an increased risk of mislateralization by IPSS by 10 times (OR 10.4, 95% CI 1.3-232.1, p = 0.057), while directional cross filling had a decreased risk of mislateralization (OR 0.096, 95% CI 0.0043 - 0.80, p = 0.057), though this was outside of statistical significance. A multivariate logistic regression model designed to predict IPSS mislateralization using angiographic IPS cross filling, basilar venous plexus filling, and the bilateral cross filling pattern achieved an AUC of 0.78 (95% CI 0.61 - 0.95, p = 0.015; Fig. 3).
Conclusion: Cases in which the IPS showed bilateral cross filling following contrast injection from either side demonstrated an increased risk of mislateralization during IPSS, while directional cross filling was associated with a lower risk. The presence of basilar venous plexus filling may be an effect modifier of this association, as models including this variable demonstrated a significant improvement in predicting mislateralization by IPSS.
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