Lithotripsy for salivary stones with prospective US assessment on our first 25 consecutive patients

To evaluate the predictive value of sonographic fragmentation in the successful treatment of sialolithiasis. The main objective was to streamline the management by treating the patients with three sessions of ultrasonic lithotripsy, and to compare the success rate and complications with data from the literature. A second objective was to analyse the predictive value of data from the post procedure and follow-up sonography related to therapeutic success with regard to size, site and location of stones.

Prospective follow-up of 25 patients (mean age of 43 ± 17.2 years old 11-68; 13 women, 10 men) over a period of 31 months (October 2009-April 2012) with one or more salivary calculi (19 parotid, submandibular 6) treated with extracorporeal lithotripsy (electromagnetic MINILITH SL 1, Storz Medical, Switzerland). No anaesthesia or analgesia was used. Each session of lithotripsy lasted on average 30 min. Minor complications were collected on an anonymised sheet.

Complete success (absence of clinical symptoms 3 months after the end of treatment (or the last session) and residual stones <2 mm) was observed in 36% of patients, partial success (persistence of symptoms least 3 months (lower intensity and lower frequency) or size of residual stones>2 mm) in 48% and failure (persistence of same or increased symptoms at 3 months or no change in size of the calculi) in 17% of patients. Sonographic fragmentation of the stone (p = 0.004), total energy delivered (p = 0.008) and the total number of shock waves (n = 0.045) are predictive factors of complete success. Size, salivary topography, ductal topography, mobilization of the stones, occurrence of minor side effects and total duration of treatment had no predictive value of complete success (p > 0.05). There was no significant difference between the first 5 and the last 20 patients (p = 0.367). In agreement with the literature data, the efficacy of treatment was greater for parotid than submandibular calculi.

Extracorporeal lithotripsy is an alternative to conventional surgery with no major complications. Sonographic fragmentation of calculi, total energy and total number of shock waves are predictive factors of successful treatment.