Algorithm changes in treatment of submandibular gland sialolithiasis

Submandibular sialolith migration

A middle-aged male Caucasian had rejected previous offers of surgery for submandibular gland removal in the past due to concerns about surgical complications. He presented with a month's history of submandibular swelling and severe pain, which impeded his ability to eat. Prior to admission, he had been experiencing intermittent sialadenitis for several months. Cross-sectional imaging demonstrated a 16×12 mm migratory sialolith, located superficial to the right submandibular gland within a large loculated abscess. The patient underwent an incision and drainage of the abscess under general anaesthetic and the sialolith was expressed. He was discharged home with oral antibiotics and was followed up as an outpatient. This case serves to highlight a rare complication of chronic sialolithiasis.

Proteomic analysis of sialoliths from calcified, lipid and mixed groups as a source of potential biomarkers of deposit formation in the salivary glands

Salivary stones, also known as sialoliths, are formed in a pathological situation in the salivary glands. So far, neither the mechanism of their formation nor the factors predisposing to their formation are known despite several hypotheses. While they do not directly threaten human life, they significantly deteriorate the patient's quality of life. Although this is not a typical research material, attempts are made to apply various analytical tools to characterise sialoliths and search for the biomarkers in their proteomes. In this work, we used mass spectrometry and SWATH-MS qualitative and quantitative analysis to investigate the composition and select proteins that may contribute to solid deposits in the salivary glands. Twenty sialoliths, previously characterized spectroscopically and divided into the following groups: calcified (CAL), lipid (LIP) and mixed (MIX), were used for the study. Proteins unique for each of the groups were found, including: for the CAL group among them, e.g. proteins from the S100 group (S100 A8/A12 and P), mucin 7 (MUC7), keratins (KRT1/2/4/5/13), elastase (ELANE) or stomatin (STOM); proteins for the LIP group-transthyretin (TTR), lactotransferrin (LTF), matrix Gla protein (MPG), submandibular gland androgen-regulated protein 3 (SMR3A); mixed stones had the fewest unique proteins. Bacterial proteins present in sialoliths have also been identified. The analysis of the results indicates the possible role of bacterial infections, disturbances in calcium metabolism and neutrophil extracellular traps (NETs) in the formation of sialoliths.

Economic analysis of the contribution of sialendoscopy in managing non-tumoral principal salivary gland pathology in the Réunion Island: Economic evaluation following the CHEERS methodology

GOALS

Cost analysis of the contribution of sialendoscopy in the treatment of non-tumoral pathologies of the main salivary glands, in Réunion Island, a French overseas territory.

OBJECTIVES

Calculation and comparison of median pricing (i.e., median payment to the healthcare establishment) per patient before and after the introduction of sialendoscopy, in the only regional establishment practicing sialendoscopy and in the whole of Réunion Island. Material and method A multicenter retrospective cost study was conducted over an 8-year period, before and after the introduction of sialendoscopy (period A: 2011-2014 and period B: 2015-2018), according to the CHEERS guidelines for economic studies, and included inpatients with non-tumoral pathology of the main salivary glands, whether treated by sialendoscopy or not.

RESULTS

Two hundred sixty-five patients were included, 139 of whom were treated by sialendoscopy: 74 in 2011-2014 and 191 in 2015-2018. Between the two periods, median pricing in the only center practicing sialendoscopy did not vary significantly: €3468 vs. €3368 (i.e., +2.9% (P=0.1)). In the Island as a whole, pricing increased significantly: €598 vs. €2332, (i.e., +390% (P<0.0001)).

CONCLUSION

Sialendoscopy is cost-effective in France in the public healthcare sector if outpatient management is optimal, but significantly increases the public health budget. It makes it possible to recruit and manage previously untreated patients (small stones, salivary strictures, etc.).

Medical analysis of the contribution of sialendoscopy in managing non-tumoral main salivary gland pathology in Reunion Island: Observational study following STROBE guidelines

GOALS

To perform a medical analysis of the contribution of sialendoscopy in the treatment of non-tumoral pathologies of the main salivary glands, in Reunion Island, a French overseas territory.

MATERIAL AND METHOD

A multicenter retrospective observational study was conducted for an 8-year period, before and after introduction of sialendoscopy (2011-2014 and 2015-2018), following STROBE guidelines.

OBJECTIVES

To compare populations treated before (period A) and after (period B) the introduction of sialendoscopy in terms of clinical characteristics, and analyze the characteristics of patients treated by sialendoscopy.

RESULTS

Two hundred and sixty-five patients were included: 74 in 2011-2014 and 191 in 2015-2018; 139 had sialendoscopy. Populations A and B were comparable except for the proportion of parotids treated (9% vs. 31%, respectively; P<0.0001), and smaller stones (11mm vs. 7.4mm, respectively; P=0.003). One hundred and ten pure sialendoscopies and 29 combined routes (20.8%) were performed: 63% submandibular and 37% parotid. Median age was 46 years. The M/F sex ratio was 0.96. Thirty-seven patients presented stenosis. There were 10 cases of papillary catheterization failure (7.1%), and 16 false routes or creation of false channels (11.5%), including 9 during the learning period. The rate of crossover to gland resection decreased: 10.45% for 2015-2016 and 5.56% for 2017-2018.

CONCLUSION

Although follow-up ranged between 12 and 55months (median, 30months), sialendoscopy appeared to be a useful and reliable technique, with a role in therapeutic strategy for the management of non-tumoral salivary pathologies in Reunion Island.

Trial Proteomic Qualitative and Quantitative Analysis of the Protein Matrix of Submandibular Sialoliths

Our studies aimed to explore the protein components of the matrix of human submandibular gland sialoliths. A qualitative analysis was carried out based on the filter aided sample preparation (FASP) methodology. In the protein extraction process, we evaluated the applicability of the standard demineralization step and the use of a lysis buffer containing sodium dodecyl sulfate (SDS) and dithiothreitol (DTT). The analysis of fragmentation spectra based on the human database allowed for the identification of 254 human proteins present in the deposits. In addition, the use of multi-round search in the PEAKS Studio program against the bacterial base allowed for the identification of 393 proteins of bacterial origin present in the extract obtained from sialolith, which so far has not been carried out for this biological material. Furthermore, we successfully applied the SWATH methodology, allowing for a relative quantitative analysis of human proteins present in deposits. The obtained results correlate with the classification of sialoliths proposed by Tretiakow. The performed functional analysis allowed for the first time the selection of proteins, the levels of which differ between the tested samples, which may suggest the role of these proteins in the calcification process in different types of sialoliths. These are preliminary studies, and drawing specific conclusions requires research on a larger group, but it provides us the basis for the continuation of the work that has already begun.

A Novel Approach for the Treatment of Sialolithiasis that Preserves Salivary Duct Anatomy

OBJECTIVE

The sialendoscopy era in the treatment of salivary gland stones has reduced the use of classical surgical methods. However, the miniature ducts and tools may cause difficulties in removing large sialoliths. Therefore, invasive combined oral surgeries or gland resection may be considered. We searched for the most suitable method in order to stay in line with the minimally invasive approach that preserves the ductus anatomy, and that can reduce the surgical fears of patients.

MATERIALS AND METHODS

The study included 84 cases (23 parotid and 61 submandibular) in whom stones were fragmented by pneumatic lithotripsy and removed between January 2015 and January 2020. The parotid cases comprised 7 females and 16 males, and the submandibular cases comprised 25 females and 36 males. Intraductal lithotripsy was performed using pneumatic lithotripter. This study has fourth level of evidence.

RESULTS

Based on total number of cases (n = 84), success rate was 67/84 (79.7%) immediately after sialendoscopy, and overall success rate was 77/84 (91.6%). Based on number of stones treated (n = 111), our immediate success rate was 94/111 (84.6%), and overall success rate was 104/111 (93.7%). The success criteria were complete removal of the stone and fragments in a single sialendoscopy procedure and resolution of symptoms.

CONCLUSIONS

We successfully treated salivary gland stones, including L3b stones, in our patient cohort with sialendoscopy combined with pneumatic lithotripsy. The lithotripsy method that we have adapted seems to be more useful and cost-effective compared to its alternatives. We were also able to preserve the ductus anatomy and relieve patients' concerns.Level of Evidence: Level IV.

Classification of submandibular salivary stones based on ultrastructural studies

INTRODUCTION

Sialolithiasis remains a clinical problem with unclear etiopathogenesis, lack of prevention methods, and only surgical treatment.

MATERIALS AND METHODS

An ultrastructure examination of submandibular sialoliths obtained from patients with chronic sialolithiasis was conducted using a scanning electron microscope and X-ray photoelectron spectroscopy.

RESULTS

Based on the results, we divided sialoliths into three types: calcified (CAL), organic/lipid (LIP), and mixed (MIX). The core structure of the CAL and MIX is very similar. The core of the LIP has a prevalence of organic components. The intermediate layers' structure of the CAL is different from LIP and MIX. In LIP and MIX, the organic component begins to increase in intermediate layers rapidly. The structure of the superficial layers for all types of sialoliths is similar.

CONCLUSIONS

We introduced a new classification of the submandibular salivary gland stones. Based on the results, it can be said that sialoliths type CAL and LIP have their separate path of origin and development, while MIX is formed as CAL stone, and the further pathway of their growth passes as LIP stones. Organic components were much more than inorganic in all layers of salivary gland stones, which highly prevents their dissolution in the patient's salivary gland duct.

In Vivo Accuracy of Ultrasound for Sizing Salivary Ductal Calculi

OBJECTIVES

The present study was developed to evaluate the accuracy of in vivo ultrasound sizing for parotid and submandibular salivary gland calculi, as compared with ex vivo pathology sizing with a standard plastic ruler after extraction.

STUDY DESIGN

Retrospective chart review.

SETTING

Ultrasound is frequently used to size salivary calculi and make treatment decisions, but the accuracy of measurements from this modality has not been validated.

SUBJECTS AND METHODS

We evaluated and reviewed the charts and ultrasound examinations of 167 patients who underwent procedures for the treatment of sialolithiasis involving the parotid and submandibular glands. US examinations were performed between 2009 and 2016 in a tertiary-level hospital setting by the senior author. Measurements were collected from ultrasound evaluation before sialolithotomy, and pathology measurements were taken after removal. Ultrasound measurements in millimeters were compared with the measurements collected with a ruler. The differences were calculated and compared.

RESULTS

A total of 167 calculi measurements were compared. Good concurrent validity between pathology and ultrasound measurements was suggested by a Pearson correlation of 0.92 (95% CI, 0.887-0.937). On Bland-Altman plot, correlation of the difference between US and pathology measurements showed a mean difference of 0.095 mm (95% CI, -0.19 to 0.38 mm) with a limit of agreement ranging from -3.59 mm (95% CI, -3.84 to -3.34 mm) to +3.78 mm (95% CI, +3.53 to +4.03 mm).

CONCLUSIONS

Ultrasound is an accurate, relatively precise, and minimally invasive imaging tool for salivary gland sialolithiasis. Preoperative size of calculi can be used to guide management and clinical decision making.

LEVEL OF EVIDENCE

2C.

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.

Ultrastructural analysis of the submandibular sialoliths: Raman spectroscopy and electron back-scatter studies

The aim of work was the epidemiological analysis of the occurrence of sialolithiasis of the submandibular gland in adults and the evaluation of the ultrastructure of salivary stones. The study sample consisted of 44 sialoliths. Analysis of the structure and chemical composition of sialoliths was performed using a Scanning Electron Microscope and Raman Spectroscopy. Comparing our results with the literature we can say that the epidemiology of sialolithiasis has not changed significantly over the past 50 years. A wide variety of sialoliths structure was observed. In 75% (33) cases a layered structure of salivary stones was observed, while in 25% (11) - homogeneous structure. The various distribution of organic and inorganic components was observed among all the analyzed sialoliths. Raman spectroscopy allows for preliminary analysis of the sialoliths structure with only a qualitative assessment of their composition, which significantly reduces the research value of this method. The presence of organic and inorganic compounds in the core and inner layers of the salivary glands stones confirms 2 basic theories of the formation of sialoliths: inflammation and deposition of the inorganic component as a result of disruption of saliva flow in the salivary glands.

Removal of stones from the superficial lobe of the submandibular gland (SMG) via an intraoral endoscopy-assisted sialolithotomy

OBJECTIVES

Sialolithiasis is the most common cause of chronic sialadenitis of the submandibular gland (SMG). Symptomatic superficial lobe stones are often treated by submandibulectomy. A gland preserving operation allows for transoral stone removal through endoscopically assisted sialolithotomy. Herein, we provide clinical and sonographical follow-up data in patients who underwent sialolithotomy under general anesthesia.

MATERIALS AND METHODS

Sixty patients treated at the Department of Oral and Maxillofacial Surgery at Düsseldorf University Hospital for superficial lobe sialolithiasis of SMG were included in this study. All received transoral sialolithotomy under general anesthesia. Follow-up was conducted via standardized patient questionnaires, clinical examination, and B-mode and color Doppler sonography.

RESULTS

Mean patient age was 48.9 years. 56.6% of right and 43.4% of left SMG were affected. Mean follow-up was 45 months. Fifty-five of 59 detected stones could be removed. Mean operation time was 71 min. 3.3% of patients reported recurrent episodes of postoperative pain and 10% felt recurrent episodes of gland swelling. Persistent postoperative lingual nerve hypesthesia was described in one patient. No facial nerve damages occurred. Salivary flow rates remained reduced in most of the affected glands upon stone removal. Sonographical follow-up data of the previously affected SMG after intraoral endoscopy-assisted sialolithotomy showed a regular gland size in 70.8% of cases, a parenchyma free of inflammation in 93.8%, and without signs of fibrosis in 72.9% of cases. 68.7% of patients showed a regular structure of Wharton's duct at time of follow-up. In total, 89.6% of patients were diagnosed stone-free within both glands on follow-up. No case required subsequent submandibulectomy.

CONCLUSIONS

Sialolithotomy of Wharton's duct for removal of stones from the SMG's superficial lobe is a promising alternative to submandibulectomy.

CLINICAL RELEVANCE

Reduction of postoperative morbidity through endoscopically assisted sialolithotomy for removal of superficial lobe stones from SMG.

TRIAL REGISTRATION

Ethics Committee of Heinrich-Heine-University Düsseldorf (no. 5586).

Outcomes of interventional sialendoscopy for obstructive salivary gland disorders: an Italian multicentre study

Interventional sialendoscopy has become the predominant therapeutic procedure for the management of obstructive salivary disorders, but only a few multicentre studies of large series of patients with a long-term follow-up have been published. This Italian multicentre study involved 1152 patients (553 females; mean age 50 years) who, after at least a clinical and ultrasonographic evaluation, underwent a total of 1342 diagnostic and interventional sialendoscopies, 44.6% of which involved the parotid gland. 12% (n = 138) of patients underwent multiple treatments. The procedure was successful in 1309 cases. In 33 cases (2.4%) the procedure could not be concluded mainly because of complete duct stenosis (21 cases). Salivary stones were the main cause of obstruction (55%), followed by ductal stenosis and anomalies (16%), mucous plugs (14.5%) and sialodochitis (4.7%). Complete therapeutic success was obtained in 92.5% of patients after one or more procedures, and was ineffective in < 8%. Untoward effects (peri and postoperative complications) were observed in 5.4% of cases. Sialendoscopy proved to be an effective, valid and safe procedure in the diagnostic and therapeutic management of non-neoplastic obstructive salivary gland diseases.

Prognostic factors for therapeutic sialendoscopy

Objective:

To review our experience with therapeutic sialendoscopy in both the submandibular and parotid glands in order to determine prognostic factors and improve successful outcomes.

Study design:

Single-centre, retrospective chart review.

Method:

The medical records of patients who had undergone sialendoscopy for sialolithiasis were reviewed, and demographic details, stone data (location, size, multiplicity, mobility), and operative technique and success were recorded.

Results:

Eighty-five patients were included: 70 patients with submandibular stones and 15 with parotid stones. Sialendoscopy was successful in all cases. Complete endoscopic removal was successful in 51 per cent of patients with submandibular stones and 47 per cent of those with parotid stones. Size (less than 5 mm) and distance from the papilla (less than 3 cm) were significant factors affecting success for patients with submandibular duct stones. However, this was not the case for patients with parotid duct stones, with neither variable achieving significance; nevertheless, numbers were small.

Conclusion:

Stone size and location significantly affect the success of therapeutic sialendoscopy in submandibular glands.

Sialendoscopy under local anaesthesia

CONCLUSIONS

In most cases, both diagnostic and interventional sialendoscopy are well tolerated under local anaesthesia (LA) or under local anaesthesia with sedation (LAS), with reasonably low patient-reported discomfort. Sialendoscopy can be considered a patient-friendly and relatively painless, gland-preserving, minimally invasive procedure suitable for day surgery.

OBJECTIVE

To investigate patient experience and compliance in sialendoscopy under LA/LAS.

METHODS

This prospective study was conducted at an academic tertiary-care university hospital. During a period of 22 months, 89 patients between ages 16-81 years underwent diagnostic or interventional sialendoscopy under LA (20%) or LAS (80%). After the operation the patients filled in a questionnaire formulated by the authors concerning their procedure-related experiences. Patients' demographic data, ASA status score, pre- and intra-operative blood pressure and heart rate measurements, affected gland, operation time, intervention type, as well as pre-, peri-, and postoperative medication were gathered later from the medical records.

RESULTS

The level of discomfort and pain experienced during the operation was assessed as 'mild' or 'none' by 85% and 89% of the patients, respectively. The level of pain experienced after the operation was 'major' in 4% of patients and 'mild' or 'none' in the majority (87%) of patients. The patients' estimations showed no significant difference between the diagnostic and interventional procedures, although it seems that patients who underwent stone removal by transoral incision experienced the operation as a bit more uncomfortable and painful than other patients. Afterwards 97% of patients stated that they would agree to a new LA/LAS sialendoscopy in the future if needed.