Clinical study of endoscopy-assisted lithectomy of parotid gland calculi via a transoral approach

Abstract

Objective: To investigate the indications and long-term outcomes of endoscopy-assisted removal of parotid gland calculi via a transoral approach. Methods: From August 2005 to December 2016, 158 consecutive patients with parotid gland calculi underwent endoscopy-assisted lithectomy transorally. They included 71 males and 87 females, with an age of 5-84 years. The immediate safety and effectiveness were evaluated. After surgery, the patients were followed up, and gland function was analyzed on the basis of clinical manifestations, sialography, scintigraphy and sialometry. Postoperative sialograms were categorized into 2 types: ①type Ⅰ, the main duct was normal or had ectasia and stenosis, but no persistent contrast was seen on the functional film; ②type Ⅱ, the main duct had ectasia or stenosis, with persistent contrast media on the functional film. Results: Under one endoscopic procedure, the stones (or foreign bodies) were completely removed in 134 cases and almost completely removed in 10 cases, with a success rate of 91.1% (144/158). Of the 144 successful cases, the treatment options included direct basket retrieval or forceps grasping in 77 cases, basket entrapment with direct ostium incision in 36, basket capture with perio-ostium incision in 23 and perio-ostium incision in 8 cases with impacted stones. In two of the initial 14 failure cases, the stones were discharged spontaneously 3 months after operation. During 3-120 months' follow-up (mean 36 months) of the 146 patients, one had recurrent stone, two developed ductal obturation, 16 had mild symptoms, and the remaining 127 cases were asymptomatic. Of the postoperative sialograms in 34 stone-free patients 25 were type Ⅰ, 9 were type Ⅱ. Both scintigraphy and saliva flow rate indicated an improvement of the affected gland function in some degree (P<0.05). Conclusions: Transoral endoscopy-assisted removal of parotid gland calculi is a safe and effective technique. It is mainly indicated for mobile stones in the main duct or impacted stones in the anterior third of the Stensen's duct. Sialography, scintigraphy and sialometry show postoperative improvement of gland function in most of the cases.