Bilateral inferior petrosal sinus sampling

Abstract

Simultaneous bilateral inferior petrosal sinus sampling (BIPSS) plays a crucial role in the diagnostic work-up of Cushing’s syndrome. It is the most accurate procedure in the differential diagnosis of hypercortisolism of pituitary or ectopic origin, as compared with clinical, biochemical and imaging analyses, with a sensitivity and specificity of 88–100% and 67–100%, respectively. In the setting of hypercortisolemia, ACTH levels obtained from venous drainage of the pituitary are expected to be higher than the levels of peripheral blood, thus suggesting pituitary ACTH excess as the cause of hypercortisolism. Direct stimulation of the pituitary corticotroph with corticotrophin-releasing hormone enhances the sensitivity of the procedure. The procedure must be undertaken in the presence of hypercortisolemia, which suppresses both the basal and stimulated secretory activity of normal corticotrophic cells: ACTH measured in the sinus is, therefore, the result of the secretory activity of the tumor tissue. The poor accuracy in lateralization of BIPSS (positive predictive value of 50–70%) makes interpetrosal ACTH gradient alone not sufficient for the localization of the tumor. An accurate exploration of the gland is recommended if a tumor is not found in the predicted area. Despite the fact that BIPSS is an invasive procedure, the occurrence of adverse events is extremely rare, particularly if it is performed by experienced operators in referral centres.

Diagnostic tests for Cushing's syndrome differ from published guidelines: data from ERCUSYN

“…Thus, this invasive procedure appears to yield a better diagnostic accuracy than MRI and dynamic testing used for the differential diagnosis of ACTH-dependent CS. Therefore it should be considered a useful diagnostic tool to confirm a pituitary source of ACTH overproduction, mainly in those patients with sustained hypercortisolism having a negative MRI and/or inconclusive biochemical evaluation (36,37,39,40,41,42,43). Although the ERCUSYN results, obtained in the largest series published to date, suggest that IPSS is extensively used across Europe, it was not reported in some countries, indicating that its use should be further implemented, for instance, by supporting technical skills training and procedure supplies acquisition.…”

Paediatric Cushing’s disease — a literature review of epidemiology, pathogenesis, clinical symptoms, and diagnostics

“…Having excluded 22 lesions that were either centrally located or bilateral, the percentage of predictive lateralisation increased to 70% [74]. In contrast to this result, four other analyses of smaller groups [30,69,75,76]: 41, 27, 11, and 17 children, stated that ACTH sampling gives a better prediction of the site of the microadenoma than that by pituitary MR imaging. The first one [30] showed that BSIPSS correctly predicted the tumour position in all (4) cases; in the second [75] and third [76] research there was concordance between the BSIPSS finding and the position of the microadenoma at surgery in, respectively, 81% (17/21) and 91% (10/11) patients.…”

“…Bilateral simultaneous inferior petrosal sinus sampling is routinely performed in adult practice when the MRI does not show unequivocally a pituitary adenoma [30]. Bilateral simultaneous inferior petrosal sinus sampling is a highly specialised technique and should be performed by experienced interventional neuroradiologists with a team of trained operators [30,69]. In the majority of cases, general anaesthesia (GA) is not required; however, in young children GA may be necessary [30,70].…”

“…ACTH is measured at baseline and at 3', 5', and 10' after oCRH administration (1 μg/kg, max 100 μg). Because it has been shown that each patient could have in one petrosal sinus (left or right) a much higher percentage of total ACTH [71], blood samples must be taken from both inferior petrosal sinuses to avoid making an erroneous diagnosis of ectopic ACTH secretion [69].…”

Diagnostic accuracy of Bilateral Inferior Petrosal Sinus Sampling: The Experience of a Tertiary Centre

“…The localization was suggested when the inter-sinus gradient was > 1. 4. The results obtained were compared with the post operatory results: compatible histology and positive immunohistochemistry to adrenocorticotrophic hormone and/or the presence of criteria of cure.…”