Long-term evaluation of extracorporeal shock wave lithotripsy in the treatment of salivary stones

Contemporary Review of Submandibular Gland Sialolithiasis and Surgical Management Options

One of the most common disorders of the salivary glands is obstructive sialolithiasis. Salivary gland obstruction is important to address, as it can significantly impact patient quality of life and can progress to extensive cellulitis and abscess formation if left untreated. For small and accessible stones, conservative therapies often produce satisfactory outcomes. Operative management should be considered when stones are inaccessible or larger in size, and options include sialendoscopy, laser lithotripsy, extracorporeal shockwave lithotripsy, transoral surgery, and submandibular gland adenectomy. Robotic approaches are also becoming increasingly used for submandibular stone management. The purpose of this review is to summarize the modern-day management of submandibular gland obstructive sialolithiasis with an emphasis on operative treatment modalities. A total of 77 articles were reviewed from PubMed and Embase databases, specifically looking at the pathophysiology, clinical presentation, diagnosis, and management of submandibular sialolithiasis.

Success rate and complications of sialendoscopy and sialolithotripsy in patients with parotid sialolithiasis: a systematic review

PURPOSE

To assess the success rate and complications of sialendoscopy and sialolithotripsy for parotid sialolithiasis.

MATERIALS AND METHODS

A total of 228 articles were identified by the electronic database search regarding the topics sialendoscopy and sialolithotripsy. Following independent then joint review of titles and abstracts, 109 articles were selected for the full review. Thirteen of these were chosen for data extraction from which 1285 patients with parotid salivary stones were identified. Extracted data included number of patients, age, gender, location, management, and outcomes.

RESULTS

All articles combined, 1285 patients with parotid salivary stones were included with a successful treatment in 1139 patients. The success rated ranged from 71.4 to 100% with a mean of 88.7%. Both partial as complete success was achieved. Although minor complications were frequent, no major complications occurred.

CONCLUSIONS

Sialendoscopy and sialolithotripsy are best suited as first choice treatment-if conservative therapy failed-for the management of parotid gland sialolithiasis. It is a valuable and feasible treatment option with no major complications. Selection of cases will ensure the best prognosis. Although there is no indefinite stone size, the smaller the calculus, the greater the probability of a symptom-free patient.

A gland-sparing, intraoral sialolithotomy approach for hilar and intraparenchymal multiple stones in the submandibular gland

Multiple intraglandular sialolithiasis for stones deep in the glandular parenchyma may require submandibulectomies, especially if sialendoscopic facilities are unavailable. We describe a gland-sparing intraoral sialolithotomy approach for both hilar and intraparenchymal multiple sialoliths. Nine patients with obstructive sialadenitis resulting from multiple sialoliths in both the deep hilar region and the submandibular gland parenchyma were selected for this study. Ultrasonography and computer tomography (CT) scans were performed to determine the location, number and sizes of the calculi and the distance between hilar and intraparenchymal sialoliths. All sialoliths were removed via gland-sparing, intraoral sialolithotomy. In all, 27 stones were found in the 9 patients. The hilar and deeper sialoliths were 4.5–11 and 0.8–4.5 mm, respectively, in diameter. The largest distance between the hilar and intraparenchymal sialoliths was 28.3 mm. Sialoliths in the hilar region were excised through an intraoral incision before deeper intraparenchymal stones were eased out of the same incision site. Postoperative follow-up imaging verified complete sialolith removal. Therefore, submandibular gland multiple sialoliths in the hilum and parenchyma can be successfully removed via an intraoral sialolithotomy under general anesthesia, thereby preserving the gland and restoring its secretory function.

Transoral submandibulotomy for deep hilar submandibular gland sialolithiasis

OBJECTIVES/HYPOTHESIS

To assess the long-term results after transoral submandibulotomy for stones located in the deep hilar and intraparenchymal submandibular region.

STUDY DESIGN

Retrospective cohort analysis.

METHODS

Retrospective evaluation including all patients treated with transoral submandibulotomy for sialolithiasis at a tertiary referral center.

RESULTS

Complete stone removal at the first transoral surgical treatment was achieved in 185 of 234 patients (79.1%). One hundred seventy-five of the 234 patients were followed up for a mean of 31.2 ( ± 20.5) months. During the follow-up period, 140 of the 175 patients (80.0%) became symptom free after one operation. In patients with residual symptoms, no further treatment was needed in 12 patients (6.9%) due to the mildness of the symptoms; 23 patients (13.1%) received further therapy, which was successful in 15 cases. Submandibulectomy only had to be performed in 3.4% of the patients with follow-up (6/175). In a questionnaire survey, 91.4% of the patients stated that they would be prepared to have the same operation again.

CONCLUSIONS

These findings show that transoral removal of submandibular sialoliths located in the deep hilum or adjacent intraglandular parenchyma is an effective treatment that can be assisted by additional measures. The techniques described show high success rates, good long-term results, low complication rates, and they avoided the need for submandibulectomy in >95% of cases.

LEVEL OF EVIDENCE

4. Laryngoscope, 127:2038-2044, 2017.

Structure and growth of sialoliths: computed microtomography and electron microscopy investigation of 30 specimens

Theories have been put forward on the etiology of sialoliths; however, a comprehensive understanding of their growth mechanisms is lacking. In an attempt to fill this gap, the current study has evaluated the internal architecture and growth patterns of a set of 30 independent specimens of sialoliths characterized at different scales by computed microtomography and electron microscopy. Tomography reconstructions showed cores in most of the sialoliths. The cores were surrounded by concentric or irregular patterns with variable degrees of mineralization. Regardless of the patterns, at finer scales the sialoliths consisted of banded and globular structures. The distribution of precipitates in the banded structures is compatible with a Liesegang-Ostwald phenomenon. On the other hand, the globular structures appear to arise from surface tension effects and to develop self-similar features as a result of a viscous fingering process. Electron diffraction patterns demonstrated that Ca- and P-based electrolytes crystallize in a structure close to that of hydroxyapatite. The organic matter contained sulfur with apparent origin from sulfated components of secretory material. These results cast new light on the mechanisms involved in the formation of sialoliths.

Algorithm changes in treatment of submandibular gland sialolithiasis

Our research was conducted to determine the algorithm changes during the treatment of submandibular sialolithiasis. Two time periods were compared between 2004-2008 and 2009-2012. The turning point was December 2008, when sialendoscopy procedure was introduced. In the first period, 48 patients were treated: 31 outpatient duct incisions with stone evacuation and 17 surgical excision of submandibular gland. In the second period, 207 sialendoscopy procedures were performed on 197 patients. Out of this particular group, 158 patients were diagnosed with pathological obstruction of salivary glands and 64 of them were confirmed to have sialolithiasis of submandibular gland. Deposits of calcifications in 40 individuals (62.5 %) affected by sialolithiasis were removed endoscopically; however, in 21 patients, due to the increased circumference of the stone, the intimate association of deposits within the wall of the duct along with its presence inside the deep portions of the gland, double approach (incision of the floor of the mouth in hilar area and sialendoscopy) was performed. Three individuals had their salivary glands totally removed due to the presence of calcified deposits within the glandular parenchyma. Our results allow us to affirm that sialendoscopy is the current treatment of choice for submandibular glands affected by sialoliths. Indication for a complete removal of the gland is becoming uncommon as a first line treatment although still indispensable in chosen cases.

Sialoendoscopy and combined approach for the management of salivary gland stones

The introduction of minimally invasive surgical procedures has significantly reduced the rate of major salivary gland removal due to sialolithiasis. The aim of this study is to assess the effectiveness of sialoendoscopy, rate of salivary fistula or natural ostium stenosis in parotid sialolithiasis treatment. The endpoint was to analyse the efficiency of a combined transcutaneous and endoscopic approach in the removal of refractory and impacted stones in most difficult cases.

STUDY DESIGN

prospective study, tertiary university centre, between XII 2008 and XI 2011, 185 sialendoscopies (SE) were performed in 162 patients. Within the group of 29 patients with parotid sialolithiasis endoscopy was the definite treatment in 15 cases (53 %), in 9 cases lithotripsy (ESWL) was necessary and in 5 patients who failed SE and lithotripsy, a combined approach was performed. This approach comprised both SE and open surgery. We observed no salivary fistula formation after the incision of the duct. Stenosis of the natural ostium thanks to the insertion of stent was observed only in one case. Sialoendoscopy is the method of choice with a high rate of success and gland preservation in small and medium stones. The combined transcutaneous and endoscopic approach is indicated for large stones, for complications after and contraindications in using minimally invasive procedures. Short and medium term follow up shows that surgery can be performed with a high rate of success.

Extracorporeal lithotripsy techniques for salivary stones

Over the past 20 years, development of minimally invasive therapies has led to the use of extracorporeal shock wave lithotripsy (ESWL) to treat salivary stones. The two main energy sources are piezoelectric and electromagnetic extracorporeal lithotripsy. Both have the aim of fragmenting the stones. ESWL is considered the treatment of choice for all parotid calculi and submandibular perihilar or intraparenchymal stones of less than 7 mm. Continuous ultrasonographic monitoring during the procedure reduces the number of untoward effects. The main limitations are the need for multiple sessions and residual stone fragments inside the duct system.

Combined Endoscopic and Transcutaneous Approach for Parotid Gland Sialolithiasis: Indications, Technique, and Results

OBJECTIVE: Despite all the advances of minimally invasive surgery, refractory stones remain in 10 to 20 percent of all cases of parotid gland sialolithiasis, and persistence of the symptoms makes removal of the gland inevitable. In some of these cases, however, it may be possible to conserve the gland using a combination of endoscopic and transcutaneous procedures.

STUDY DESIGN: Case series with chart review.

SETTING: Tertiary referral center.

SUBJECTS AND METHODS: Nine patients treated with a combined endoscopic transcutaneous operation were evaluated. During this procedure, the stone is removed through a skin incision under endoscopic guidance. Indications were sialolithiasis refractory to treatment (n = 5), sialolithiasis with complications (n = 2), contraindications to primary minimally invasive surgery (n = 1), and primary treatment (n = 1). In seven cases, the stones were extracted. Simultaneous resection of a sialocele was carried out in one case, and simultaneous resection of a saliva-cutaneous fistula was carried out in another. A stent was inserted in 66.7 percent of the cases.

RESULTS: Treatment was successful in 88.9 percent of the patients. All of these patients were free of stones and symptoms, and glandular function was maintained both clinically and on ultrasound assessment. Complete parotidectomy had to be carried out in one case because it was not possible to reconstruct the duct system.

CONCLUSION: The combined operation offers a further option for gland-conserving treatment in cases with obstructive salivary gland disease, especially sialolithiasis. At present, it is indicated for cases that are resistant to treatment after sialendoscopy or extracorporeal shock wave lithotripsy. The gland resection rate can thus be further reduced.