Contrast‐enhanced ultrasound for monitoring effects of extracorporeal shock wave sialolithotripsy in sialolithiasis

Abstract

Contrast-enhanced ultrasound (CE-US) can be used for noninvasive analysis of functional vascularization. Chronically recurrent sialadenitis due to sialolithiasis of the submandibular gland is associated with increased vascularity. The aim of this investigator-initiated clinical trial was the evaluation of CE-US as a quantitative monitoring technique during gland-preserving extracorporeal shock wave sialolithotripsy (ESWL). In this prospective clinical evidence level 2c study, perfusion in patients (n = 10) with unilateral sialolithiasis of the submandibular gland was quantitatively analyzed using CE-US before and after ESWL, comparing with the respective contralateral gland. Before CE-US measurements, a subjective clinical score of complaints (range, 1-10) was documented. The contrast agent SonoVue was injected into a cubital vein. The intensity-time curve gradients (ITGs) were calculated from CE-US data. The ITGs derived from CE-US measurements revealed higher perfusion in the affected submandibular gland compared to the contralateral side. In parallel to clinical complaints, parametric CE-US data were significantly reduced after ESWL in chronic sialolithiasis-associated sialadenitis. CE-US-derived ITGs appear to be an independent and quantitative marker for treatment effects of ESWL. Clinical experience and further studies will have to validate this method as a diagnostic tool to decide especially whether to proceed to sialoadenectomy in therapy-refractory cases.