Clinical Trial Summary
Endoscopic trans-sphenoidal pituitary endoscopic surgery is one of the main axes of
management of tumours of the sellar region.
Central diabetes insipidus is a frequent complication of endoscopic trans-sphenoidal
pituitary endoscopic surgery, with a prevalence of up to 30% of cases. It is the consequence
of insufficient secretion of the anti-diuretic hormone arginine vasopressin (AVP) by the
posterior pituitary (Melmed et al, 2017).
In the absence of specific treatment, diabetes insipidus can lead to severe ionic and osmotic
disorders, mainly acute dehydration with the risk of severe consequences particularly
neurological.
Monitoring for the appearance of diabetes insipidus is therefore necessary from the immediate
post-operative period.
To date, diabetes insipidus is initially suspected before the appearance of major polyuria.
Several biological assays (urinary density, natraemia, urinary osmolarity and plasma) can
help to confirm the diagnosis, but the sensitivity and specificity of these biomarkers
remains quite low for this indication.
The determination of MVA is difficult because this hormone is unstable ex vivo. To date, its
use in current practice remains complicated.
MVA and copeptin are derived from the same precursor and are therefore co-secreted by the
pituitary gland in equimolar proportions.
Copeptin has a relatively short in vivo half-life of about 25 minutes, as does MVA, but is
more stable in vitro when blood has been drawn.
Its use in the early diagnosis of diabetes insipidus after pituitary surgery could therefore
be of interest.
Objective is to study the interest of copeptin dosage as an early predictive marker for the
diagnosis of post-operatice diabetes insipidus in trans-sphenoidal endoscopic pituitary
surgery.
