CT Navigation and sialendoscopy‐assisted transfacial removal of a parotid stone: A technical note

Sialolithiasis is the most frequent nonneoplastic obstructive disease of the major salivary glands, being responsible for 60% to 70% of all obstructive salivary gland disorders. Between 5% and 20% of all salivary stones are found in the parotid gland, where they may remain clinically undetected for a long time or cause recurrent gland swelling and pain. Conventional sialography investigations of the morphology of the salivary gland duct system have recently been replaced by more precise and noninvasive radiological approaches, and diagnosis is now based on color Doppler ultrasonography (US), cone-beam 3D computed tomography (CBCT), and magnetic resonance sialography. Treatment depends on the exact location and size of the stone. Traditional surgical procedures such as partial or complete gland removal have now been abandoned in favor of minimally invasive approaches. Interventional sialendoscopy has proved to be highly effective in the case of stones that are smaller than 4 mm, as with extracorporeal shockwave lithotripsy (ESWL) in the case of stones with a diameter of 4 to 7 mm. Palpable stones of more than 7 mm (especially if impacted or after the failure of minimally invasive techniques) are amenable to sialendoscopy-assisted transfacial removal. However, deep parenchymal stones may be difficult to be endoscopically located due to Stensen duct strictures or kinking that may possibly prevent sialoendoscope progression. Carroll et al. have proposed using intraoperative US as a guide to overcome this challenge. An alternative means of detecting a stone is intraoperative CT navigation, which currently is primarily used for sinus and skull base surgery. We here describe a variation of the traditional transfacial approach to removing a nonpalpable parotid parenchymal stone embedded into the ductal system that involves the assistance of CT navigation and sialendoscopy.