The Laryngoscope VC 2010 The American Laryngological, Rhinological and Otological Society, Inc. Long-Term Outcome After Intraoral Removal of Large Submandibular Gland Calculi Lei Zhang, DDS, MD; Michael Escudier, MD, BDS, FDS, FDS (OM) RCS, FFGDP; Jacqueline Brown, BDS, MSc, FDSRCPS, DDRRCR; Pasquale Capaccio, MD; Lorenzo Pignataro, MD; Mark McGurk, MD, BDS, FRCS, FDSRCS, DLO is of a painful swelling of the gland at meal times when Objectives/Hypothesis: To evaluate the long- term outcome of intraoral removal of large subman- the gland auto inflates with obstructed saliva. The inci- dibular gland calculi. dence of symptomatic salivary calculi is reported to be Study Design: Retrospective cohort study. about 59 cases per million per year in the United King- Methods: A retrospective review (1995–2008) of dom,2 which implies a prevalence of 0.45% assuming a 118 patients with submandibular calculi 10 mm lifetime of 76 years.3 Some 80% to 90% of calculi are treated by intraoral surgical removal with preserva- found in the submandibular gland.4 tion of the salivary gland. Traditionally, the treatment for calculi in the proxi- Results: Calculi were completely removed in mal duct or gland has been sialoadenectomy. The main 103/118 (87.3%) cases, partially removed in 14/118 rationale determining surgical policy is the widely held (11.9%), with failure to remove any fragments in only view that proximal stones cause permanent structural 1/118 (0.8%). After a mean follow-up of 42 months, damage to the gland, which in turn are predisposed to 101/118 (85.6%) cases remained asymptomatic, 17/118 5 (14.4%) cases had modest obstructive or infective recurrent infection. It is assumed the damage incurred symptoms, 4/118 (3.4%) cases suffered recurrent by the gland is proportional to the size of the stone, which stones, and in 1/118 (0.8%) case persistent symptoms in turn is related to its duration of residence in the gland. dictated salivary gland removal. Conservative treatment measures less radical than sialoa- Conclusions: The data suggest that the major- denectomy are thought to only postpone gland excision. ity of large submandibular gland calculi can be The purpose of this study is to describe our experi- removed by gland-preserving procedures retaining an ence in treating large submandibular calculi by gland- asymptomatic salivary gland. This casts doubt on the preserving techniques. commonly held premise that salivary stones normally lead to chronic sialoadenitis, which is the basis for the current policy of sialoadenectomy. Key Words: Large calculi, submandibular gland, MATERIALS AND METHODS long-term outcome. A retrospective review was undertaken of patients with sub- Level of Evidence: 2C. mandibular sialoliths treated by minimally invasive gland- Laryngoscope, 120:964–966, 2010 preserving surgery in the Department of Oral and Maxillofacial Surgery, King’s College London and the Department of Otorhino- laryngology, University of Milan in the period from 1995 to 2008. INTRODUCTION The collective policy was to treat all symptomatic salivary Sialolithiasis is the most common cause of both calculi by minimally invasive methods and only undertake obstruction and sialoadenitis.1 The typical presentation adenectomy as a last resort. Patients underwent clinical and ultrasonographic and/or sialographic examination. Demographic From the Department of Oral and Maxillofacial Surgery, Peking details, including gender, location, number of stones, and stone University School and Hospital of Stomatology, Beijing, China (L.Z.); and size were recorded prospectively in the medical records and are the Departments of Oral and Maxillofacial Surgery, Oral Medicine, and summarized in Table I. Only patients with submandibular Dental Radiology, King’s College London Dental Institute, London, United stones 10 mm were included in the study. Kingdom (L.Z., M.E., J.B., M.M.); and the Department of Surgical Specialist Sciences, University of Milan, Milan, Italy (P.C., L.P.). In theory, the treatment available included lithotripsy, Editor’s Note: This Manuscript was accepted for publication De- basket retrieval, or intraoral surgery. However, in practice, the cember 7, 2009. first two are not applicable for large stones,6 and therefore, the The authors have no funding, financial relationships, or conflicts calculi were treated exclusively by intraoral, endoscope-assisted of interest to disclose. surgery. The surgical technique was standardized between the Send correspondence to Professor Mark McGurk, Department of two units and has been reported previously.7 In brief, an oblique Oral and Maxillofacial Surgery, Floor 23, Tower Wing, Guy’s Hospital, incision is made from the punctum of the submandibular duct London Bridge, London, UK SE1 9RT. E-mail: [email protected] along the floor of the mouth toward the third molar tooth. The DOI: 10.1002/lary.20839 sublingual gland is mobilized and retracted to expose the Laryngoscope 120: May 2010 Zhang et al.: Removal of Submandibular Gland Calculi 964 TABLE I. 118, 3.4%) accepted the modest residual discomfort with- Study Group Parameters for Intraoral Surgical Removal of out requesting further treatment. Submandibular Calculi. Parameter No. % DISCUSSION Male 71 60.2 Approximately 3,700 patients in the United King- Female 47 39.8 dom are admitted to the hospital annually with salivary Mealtime syndrome 109 92.4 gland obstruction or infection.2 Of these, an estimated One or more episodes of acute sialoadenitis 85 72.0 2,000 patients undergo sialoadenectomy. This surgery Multiple calculi (2–6) 7 5.9 has an associated small but significant morbidity both 8 8 Ductal position neurological and non-neurological. A minimally inva- sive approach preserves the gland and largely avoids Mid-third 1 0.8 this morbidity.6,9 Proximal third 37 31.4 The exact etiology and pathogenesis of salivary calculi Hilum 79 67.0 is largely unknown.3 However, it seems that calculi result Intraglandular 1 0.8 from the deposition of calcium salts around an organic 4,10 Mean Range nidus consisting of altered salivary mucins. Salivary stones can reside silently within the gland for many years. Age (yr) 54 15–85 In an analysis of 4,600 salivary stones, the mean delay Duration of obstructive symptoms (mo) 26 2–600 between initiation of symptoms and presentation for treat- Stone size (mm) 13.4 10–40 ment was approximately 5.4 years.9 Themeansizeof submandibular stones in this series was 7.2 mm.9 It is commonly held that the longer a stone resides submandibular duct. This structure is then followed to the in the gland, the more damage is incurred and the hilum of the gland, where the stone is delivered through an greater the risk of persistent sialoadenitis. If this hy- incision in the duct wall. The duct is irrigated with normal sa- pothesis is correct, then the risk of recurrent infection line and closed with fine resorbable sutures. Endoscopic following stone removal should be greatest in glands examination confirms the removal of the calculus and debris harboring large stones. The current data show that after postextraction. a mean follow-up of 42 months, only 14.4% (17/118) of After 48 hours, the patients were advised to massage the patients had recurrent symptoms. A second course of gland and ensure a constant flow of saliva with sialagogues, such as sugar-free gum. Patients were reviewed at 1 week, minimally invasive therapy cured a further 10.2% (12/ 3 months, and yearly thereafter. For the purpose of the study, 118). The majority remain asymptomatic, and only one patients were reviewed by postal questionnaire. patient with an parenchymal stone underwent adenec- tomy as the final treatment option. In this series, 4.2% (5/118) of patients had altered RESULTS lingual nerve function at 6-months postsurgery. These In the period from 1995 to 2008, 118 patients with were traction injuries incurred in gaining access to the submandibular calculi 10 mm were identified for large and deeply positioned stone. The patients describe gland-preserving treatment. In this group, 17 cases had a subtle change in perception, and touch and pressure previously undergone unsuccessful minimally invasive are perceived as normal. attempts to remove the stones. In the last decade the treatment of salivary gland Stones were successfully retrieved in 103/118 stones has changed from gland extirpation to gland-pre- 9 patients (87.3%) and partially removed in 14/118 serving surgery using minimally invasive techniques. (11.9%). The one instance in which surgery failed (1/118, An important principle that supports the move away 0.8%) was where the stone lay in the parenchyma of the from sialoadenectomy is that secretory function can submandibular gland (Table II). recover after removal of the obstruction. Animal studies Immediate postoperative complications included: have shown that cell death is uncommon after ligation swelling in 97/118 (82.2%) cases and temporary lingual of the main salivary duct, and the gland structure 11–13 nerve paresthesia in 18/118 (15.3%). Altered sensation returns to normal when the ligature is removed. persisted in 5/118 (4.2%) at 6 months postoperatively. There was no incidence of hemorrhage or ranula forma- TABLE II. tion in this cohort of patients. Immediate and Long-Term Outcome of Intraoral Surgical Removal After a mean follow-up of 42 months (range, 5–84 of Submandibular Calculi. months), 101/118 (85.6%) patients remained asymptom- Follow-Up atic and 17/118 (14.4%) had mild obstructed or infective Long-Term (%) symptoms (Table II), of which four patients (3.4%) had [Mean, 42 mo; Range, developed new stones. In this latter group (n ¼ 17), the Outcome (N¼118) Immediate (%) 5–84 mo] new symptoms were eliminated in 12 cases by subse- Stone-free 103 (87.3) 101 (85.6) quent minimally invasive therapy (lithotripsy or basket Residual stone/symptoms 14 (11.9) 16 (13.6) retrieval).