Transoral Robotic Surgery in the Management of Submandibular Gland Sialoliths: A Systematic Review

This study aimed to systematically review the literature to determine the efficacy and safety of transoral robotic surgery (TORS) in the management of submandibular gland (SMG) sialolithiasis. PubMed, Embase, and Cochrane were searched for English-language articles evaluating TORS in the management of SMG stones published up to 12 September 2022. Nine studies with a total of 99 patients were included. Eight patients underwent TORS followed by sialendoscopy (TS); 11 patients underwent sialendoscopy followed by TORS and sialendoscopy (STS); 4 patients underwent sialendoscopy followed by TORS only (ST); and 4 patients underwent TORS without sialendoscopy (T). The mean operative time amounted to 90.97 min. The mean procedure success rate reached 94.97%, with the highest for ST (100%) and T (100%), followed by the TS (95.04%) and STS (90.91%) variants. The mean follow-up time was 6.81 months. Transient lingual nerve injury occurred in 28 patients (28.3%) and was resolved in all of them within the mean of 1.25 months. No permanent lingual nerve injury was reported. TORS is a safe and effective management modality for hilar and intraparenchymal SMG sialoliths, with high procedural success in terms of successful sialolith removal, SMG preservation, and reduced risk of permanent postoperative lingual nerve damage.

Treatment of Sialolithiasis: What Has Changed? An Update of the Treatment Algorithms and a Review of the Literature

Treatment for sialolithiasis has undergone significant changes since the 1990s. Following the development of new minimally invasive and gland-preserving treatment modalities, a 40–50% rate of gland resection was reduced to less than 5%. Extracorporeal shock-wave lithotripsy (ESWL), refinement and extension of methods of transoral duct surgery (TDS), and in particular diagnostic and interventional sialendoscopy (intSE) are substantial parts of the new treatment regimen. It has also become evident that combining the different treatment modalities further increases the effectiveness of therapy, as has been especially evident with the combined endoscopic–transcutaneous approach. In the wake of these remarkable developments, a treatment algorithm was published in 2009 including all the known relevant therapeutic tools. However, new developments have also taken place during the last 10 years. Intraductal shock-wave lithotripsy (ISWL) has led to remarkable improvements thanks to the introduction of new devices, instruments, materials, and techniques, after earlier applications had not been sufficiently effective. Techniques involving combined approaches have been refined and modified. TDS methods have been modified through the introduction of sialendoscopy-assisted TDS in submandibular stones and a retropapillary approach for distal parotid sialolithiasis. Recent trends have revealed a potential for significant changes in therapeutic strategies for both major salivary glands. For the submandibular gland, ISWL has replaced ESWL and TDS to some extent. For parotid stones, ISWL and modifications of TDS have led to reduced use of ESWL and the combined transcutaneous–sialendoscopic approach. To illustrate these changes, we are here providing an updated treatment algorithm, including tried and tested techniques as well as promising new treatment modalities. Prognostic factors (e.g., the size or location of the stones), which are well recognized as having a strong impact on the prognosis, are taken into account and supplemented by additional factors associated with the new applications (e.g., the visibility or accessibility of the stones relative to the anatomy of the duct system).

An Update on Nontumorous Disorders of the Salivary Glands and Their Management for Internists

Salivary disease may present as pain or swelling in unilateral or bilateral salivary glands. Symptoms may be periprandial or recurrent and inflammatory. If a patient fails conservative treatment, they should be referred to an otolaryngologist. If there is no clear cause based on history and physical examination, sialendoscopy can be performed to directly visualize tissues, provide a diagnosis, drive treatment plans, and sometimes concurrently provide therapeutic intervention. Based on the pathology visualized on sialendoscopy, treatment options include endoscopic intervention, Botox, and gland-preserving surgical techniques, which promote healing of glandular tissue, ultimately preserving function.

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.

Transfacial lithotomy approach to intraparenchymal stones in the submandibular gland: our primary exploration

The article describes our exploration of a sialendoscopy-assisted transfacial sialolithotomy approach to intraparenchymal stones in the submandibular gland with gland preservation. Five patients with large intraparenchymal stones in the submandibular gland were included. Ultrasonography and computed tomograms (CT) were performed to locate the stones. As the large stones failed to be retrieved during endoscopy, patients were treated by a transfacial lithotomy approach with sialendoscopy. The glands were preserved in all cases. This approach can be considered an optional technique for the treatment of large intraparenchymal stones in the submandibular gland that fail to be removed during a transoral procedure.

Intraductal Lithotripsy in Sialolithiasis Using the Calculase III™ Ho:YAG Laser: First Experiences

BACKGROUND AND OBJECTIVES

To report the first experiences with a newly available Ho:YAG laser system for the treatment of salivary stones.

STUDY DESIGN/MATERIALS AND METHODS

A retrospective study in a tertiary referral center was conducted. Patients diagnosed with sialolithiasis were treated in Erlangen using the Calculase III™ Ho:YAG laser (Karl Storz, Tuttlingen, Germany). Preset parameters had a frequency of 4 Hz and energy of 0.8-1.2 J, resulting in 3.2-4.8 W. Following total fragmentation, one to two serial sialendoscopies were performed to achieve complete fragment clearance.

RESULTS

A total of 55 stones in 49 patients were treated; 17 stones in 15 submandibular glands and 38 in 34 parotids. In total, 61 laser lithotripsies (range 1-3 per stone) were performed using various modes (long, short, and burst) and with preset parameters of 4 Hz and energy of 0.8-1.2 J, resulting in effective power of 3.2-4.8 W. Complete fragmentation was achieved in all the accessible stones. Sialendoscopes, fibers, or the mode used had no significant influence on success rates. A multimodal therapy concept was employed to treat stones in 12.24% of the cases; 95.92% of the patients were ultimately stone-free, and all became symptom-free. All glands were preserved.

CONCLUSIONS

The new Calculase III™ Ho:YAG laser was effective in the treatment of sialolithiasis with no increased risk of complications in the patients or damage to the sialendoscopes. Clinical factors such as the type of gland involved, or the location and size of stones had a greater impact on success rates than the technical or preset parameters. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Neutrophil Extracellular Traps Promote the Development and Growth of Human Salivary Stones

Salivary gland stones, or sialoliths, are the most common cause of the obstruction of salivary glands. The mechanism behind the formation of sialoliths has been elusive. Symptomatic sialolithiasis has a prevalence of 0.45% in the general population, is characterized by recurrent painful periprandial swelling of the affected gland, and often results in sialadenitis with the need for surgical intervention. Here, we show by the use of immunohistochemistry, immunofluorescence, computed tomography (CT) scans and reconstructions, special dye techniques, bacterial genotyping, and enzyme activity analyses that neutrophil extracellular traps (NETs) initiate the formation and growth of sialoliths in humans. The deposition of neutrophil granulocyte extracellular DNA around small crystals results in the dense aggregation of the latter, and the subsequent mineralization creates alternating layers of dense mineral, which are predominantly calcium salt deposits and DNA. The further agglomeration and appositional growth of these structures promotes the development of macroscopic sialoliths that finally occlude the efferent ducts of the salivary glands, causing clinical symptoms and salivary gland dysfunction. These findings provide an entirely novel insight into the mechanism of sialolithogenesis, in which an immune system-mediated response essentially participates in the physicochemical process of concrement formation and growth.

Treatment strategy of hilar and intraglandular stones in wharton's duct: A 12-year experience

OBJECTIVES/HYPOTHESIS

To suggest a strategy for transoral removal of hilar and intraparenchymal submandibular stones.

STUDY DESIGN

Retrospective case series.

METHODS

Retrospective evaluation was performed for 514 consecutive patients with hilar and intraparenchymal submandibular stones treated via endoscopy-assisted surgery from January 2006 to June 2018. Three patients had bilateral stones. The stones were classified as: hilar (type I), posthilar (type II), intraparenchymal (type III), and multiple stones (type IV).

RESULTS

The affected glands included 311 with type I, 84 with type II, 65 with type III, and 57 with type IV stones. Stones were successfully removed in 478 glands (92.5%, 478/517). Main treatment techniques included hilum ductotomy in 311 glands, intraparenchymal ductotomy in 68, submandibulotomy in 14, intraductal retrieval in 74, and hilum ductotomy accompanied by intraductal retrieval in 11. At a mean 40-months follow-up of 478 successful cases, clinical outcomes were good in 425, fair in 27, and poor in 26 glands. Postoperative sialograms in 75 stone-free patients were categorized as: type I, normal (n = 6); type II, ectasia or stenosis in the main duct and no persistent contrast on functional films (n = 44); type III, ectasia or stenosis in the main duct and mild contrast retention (n = 15); and type IV, poor shape of the main duct and evident contrast retention (n = 10). Postoperative sialometry of 32 patients revealed no significant differences of the gland function between the two sides.

CONCLUSIONS

Appropriate use of various endoscopy-assisted approaches helps preserve the gland and facilitates recovery of gland function in patients with different depths of hilo-parenchymal submandibular stones.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:2360-2365, 2020.