Salivary calculi account for more than one half of cases of major salivary gland disease and are the most common cause of acute and chronic salivary gland infections. The techniques and equipment used in urolithiasis can be adapted for use in the salivary system, and initial experiences with extracorporeal salivary lithotripsy are promising. With this technique, the calculus is broken, and the fragments are subsequently washed down the duct. Drage and associates prospectively investigated the efficacy of a wire basket extractor with intermittent fluoroscopic guidance in the retrieval of salivary calculi.
Twenty-five patients with a diagnosis of salivary calculi were enrolled in the study. The main presenting symptoms were gustatory pain and swelling. Symptoms ranged in duration from three months to 20 years and varied in frequency. Fourteen patients had undergone salivary lithotripsy previously and had residual stone fragments. Stone diagnosis was established by sialography and confirmed by ultrasonography. The mean number of stones per patient was 1.67, and 16 patients had only a single calculus. Anesthesia was provided via dental block. With intermittent fluoroscopic guidance, the wire basket was passed along the duct to the stone. Patients were examined postoperatively at six weeks and six months.
Elimination of all stones from the duct was achieved in 10 patients (40 percent). Seven stones were mobile preoperatively. Incomplete removal of stone fragments because of multiple calculi or partial removal of a single stone was achieved in seven patients, one of whom underwent the procedure on two separate occasions. In these patients, 20 calculi were present, with 11 (55 percent) being completely retrieved and two being partially retrieved. In eight patients, no stone was retrieved. The most likely cause of retrieval failure was that the calculus was fixed to the duct wall (see the accompanying table).
Of the 10 patients successfully treated, eight (80 percent) were asymptomatic at follow-up. In comparison, none of the patients in whom partial removal was achieved was symptom free at follow-up.
All patients had some postoperative tenderness and swelling of the gland, lasting from one to seven days. Two patients developed a low-grade postoperative infection requiring antibiotic therapy. In one case, the calculus and basket became impacted in the gland, and surgical intervention was required.
Results of this study demonstrate that some of the salivary duct calculus was retrieved in 68 percent of patients but complete elimination of the stone from the ductal system was achieved in only 40 percent. Had more of the stones been mobile preoperatively, the complete elimination rate would probably have been higher.
The authors conclude that management of salivary calculi by use of minimally invasive techniques is becoming more promising. Basket retrieval appears to be a safe and simple procedure for mobile calculi or fragments in the middle or proximal thirds of the submandibular duct or for calculi in any region of the parotid duct. The success rate can be substantially improved with appropriate selection of patients with mobile salivary stones.