Accuracy of Ultrasound-Guided and Non-ultrasound-Guided Botulinum Toxin Injection Into Cadaver Salivary Glands

Does injection of botulinum toxin to salivary glands require ultrasound guidance?

INTRODUCTION

Injection of botulinum toxin into salivary glands is a well-established treatment for sialorrhea in children, but the absolute need for radiological guidance has not been tested.

METHODS

Single-centre study in which clinicians of varying seniority attempted blind injection of salivary glands, after which their position within or outside the gland was confirmed by ultrasound guidance before the injection is administered.

RESULTS

117 patients underwent botulinum toxin of salivary glands between November 2008 and August 2023, with 459 glands injected in total. 24 (5 %) glands were injected by medical students, 32 (7 %) by junior trainees (foundation doctors or senior house officers), 343 (75 %) by registrars or senior fellows and 36 (8 %) by consultants. 160 (68 %) of injections to the parotid gland were on target, and 74 (32 %) submandibular gland were on target (P < 0.01). No differences were detected on likelihood of success depending on seniority of practitioner, age of patient or hand dominance.

CONCLUSION

Ultrasound guidance ought to be recommended for injection of botulinum toxin into salivary glands regardless of the seniority of the practitioner.

Anatomical Guidelines and Technical Tips for Neck Aesthetics with Botulinum Toxin

Botulinum toxin can be used for various purposes to enhance neck aesthetics, addressing concerns such as platysmal bands, optimizing the cervicomental angle, preventing worsening of horizontal neckline and decolletage lines during aging, submandibular gland hypertrophy, and hypertrophied superior trapezius muscle. Understanding the anatomy of muscles such as the trapezius, platysma, and submandibular gland is crucial for achieving desirable outcomes with botulinum toxin administration. Techniques for injecting botulinum toxin into these muscles are discussed, emphasizing safety and efficacy. Specific injection points and methods are detailed for treating platysmal bands, optimizing the cervicomental angle, addressing submandibular gland hypertrophy, and managing hypertrophied superior trapezius muscle. Careful consideration of anatomical landmarks and potential complications is essential for successful botulinum toxin injections in these areas.

Using Neuromodulators for Salivary, Eccrine, and Apocrine Gland Disorders

BACKGROUND

Sialorrhea, hyperhidrosis, bromhidrosis, and chromhidrosis are common glandular disorders that substantially impact patients' health and quality of life. Botulinum toxin can safely and temporarily decrease gland secretions by targeting the parasympathetic cholinergic neurons, resulting in diminished saliva and sweat production.

OBJECTIVE

The objective of this article is to describe the applications of neuromodulators for the treatment of salivary, eccrine, and apocrine glands.

METHODS

PubMed was searched from inception to February 1, 2024 using search terms "neurotoxin," "botulinum toxin," "sialorrhea," "hyperhidrosis," "bromhidrosis," and "chromhidrosis."

RESULTS

Incobotulinumtoxin A and Rimabotulinumtoxin B are approved by the FDA for the treatment of sialorrhea. Onabotulinumtoxin A is the only FDA-approved botulinum toxin for axillary hyperhidrosis and is used off-label for hyperhidrosis of nonaxillary sites, bromhidrosis, and chromhidrosis. Compared to botulinum toxin serotype A, serotype B has been associated with more immunogenicity, which may have implications for patients requiring long-term treatment for chronic glandular disorders.

CONCLUSION

Neuromodulators are safe and effective for the noninvasive treatment of excess gland activity and can improve patients' quality of life. While substantial literature supports botulinum toxin treatments for hyperhidrosis, further studies are needed to characterize standard dosing and administration techniques for sialorrhea, bromhidrosis, and chromhidrosis.

Ultrasonographic Study of the Submandibular Gland for Botulinum Neurotoxin Injection

BACKGROUND

Hypertrophied submandibular glands provide a bulky contour to the lower face. Botulinum neurotoxin injection methods are commonly used for facial contouring; however, no studies have suggested injection points because of the lack of delicate anatomical information on the submandibular gland.

OBJECTIVE

The aim of this study was to determine the optimal injection site for botulinum neurotoxin injections in the submandibular gland.

MATERIALS AND METHODS

Anatomical considerations when injecting botulinum neurotoxin into the submandibular gland were determined using ultrasonography. The thickness of the submandibular gland, its depth from the skin surface, and the location of the vascular bundle were observed bilaterally in 42 participants. Two cadavers were dissected to measure the location of the submandibular gland corresponding to the ultrasonographic observation.

RESULTS

The thickest part of the submandibular gland measured 11.12 ± 2.46 in width with a depth of 4.63 ± 0.76. At the point where it crosses the line of the lateral canthus, it measured 5.53 ± 1.83 in width and 8.73 ± 1.64 in depth.

CONCLUSION

The authors suggest optimal injection sites based on external anatomical landmarks. These guidelines aim to maximize the effects of botulinum neurotoxin therapy by minimizing its deleterious effects, which can be useful in clinical settings.

Localization of the Submandibular Glands Using High-Frequency Ultrasound

BACKGROUND

Injecting botulinum toxin (BTX) into the submandibular glands (SMGs) can treat drooling symptoms in neurological diseases and improve the aesthetics of SMG hypertrophy and ptotic SMGs.

OBJECTIVES

This study aimed to define the size and position of the SMGs by high-frequency ultrasound, and to perform statistical analysis to improve the safety and accuracy of BTX injection therapy.

METHODS

Neck ultrasonography with high-frequency ultrasound was performed on 214 volunteers. The length, height, and thickness of the SMGs, and the distance between the SMGs and the midline, the anterior border of the sternocleidomastoid, the mandible, and the surface were measured.

RESULTS

The SMGs were almond-shaped with a mean [standard deviation] length of 33.7 [4.7] mm, a thickness of 13.3 [2.9] mm, and a height of 27.6 [6.0] mm. The length and height were significantly different between underage and youth groups. The size of the SMGs did not show any notable differences with increasing BMI; however, their depth, and the distance from the mandible, midline, and anterior border of the sternocleidomastoid increased. No significant differences were observed between the affected and healthy sides in patients with microtia, hemifacial microsomia, or cleft lip and palate.

CONCLUSIONS

Ultrasound provides more comprehensive information regarding the size and position of the SMGs, which can serve as a reference in BTX therapy and in the diagnosis of SMG diseases involving size alterations.

LEVEL OF EVIDENCE: 4

Botulinum neurotoxin type A in the interdisciplinary treatment of sialorrhea in adults and children-update and practice recommendations

Sialorrhea is defined as a chronic excessive flow of saliva from the mouth, often with adverse consequences for health and quality of life of patients. In addition to currently used non-drug treatment and systemic drugs, intraglandular Botulinum Neurotoxin A (BoNT/A) injections have been examined in case studies, controlled trials and clinical practice. Two pivotal Phase III trials recently led to market approval in the USA and EU for IncobotulinumtoxinA [Xeomin®, IncoBoNT/A, Clostridium botulinum neurotoxin type A (150 kD), free from complexing proteins, Merz Pharmaceuticals GmbH] for treatment of chronic sialorrhea in adults and pediatric patients. This review provides a multidisciplinary approach to discuss the current state of sialorrhea therapy as well as benefits and current limitations of BoNT/A injections. A consensus regarding treatment recommendations made available to physicians in Germany in 2022 has now been updated here for presentation to an international audience. This review provides a framework including a flow chart for patient selection, recommendations for dosing and the injection process, as well as a discussion of therapeutic goals, long-term benefits and safety aspects. This review is aimed at supporting physicians in developing multidisciplinary and individualized treatment approaches to achieve optimal benefits for patients.

The effectiveness of ultrasound-guided injection of BTX-A in the management of sialorrhea in neurogenic dysphagia patients

Objective

To evaluate the effectiveness of ultrasound-guided injection of botulinum toxin type A (BTX-A) in treating sialorrhea.

Methods

We recruited 32 sialorrhea subjects and they received an ultrasound-guided injection of BTX-A. The extent of salivation was evaluated according to the Visual Analog Scale (VAS), Drooling Severity and Frequency Scale (DSFS), and Saliva Flow Rate (SFR). Laryngeal secretions were evaluated based on Fiberoptic Endoscopic Evaluation of Swallowing (FEES) rated according to the Murray Secretion Scale (MSS). We assessed the extent of salivation and laryngeal secretions before injection and at 1, 2, and 4 weeks after injection.

Results

The scores for the VAS, DSFS-S, DSFS-F, and DSFS-T decreased significantly at 1, 2, and 4 weeks after injection compared with before injection (p < .05). Based on VAS, the efficacy was substantially higher at 2 and 4 weeks after injection than at 1 week after injection (p < .05). According to DSFS-S and DSFS-T, the efficacy was significantly higher at 4 weeks than at 1 week after injection (p < .05). The SFR and MSS scores at 1 and 2 weeks after injection were superior to those before injection (p < .05). Meanwhile, the SFR score 2 weeks after injection was superior to that 1 week after injection (p < .05).

Conclusion

The ultrasound-guided injection of BTX-A can effectively reduce saliva secretion in patients with neurogenic dysphagia. Furthermore, it has the advantages of early onset time and lasting curative effects, which indicates that clinical promotion and application of this technique are justified.

Level of Evidence

Level 3.

Drug Therapeutics Delivery to the Salivary Glands: Intraglandular and Intraductal Injections

Salivary gland hypofunction and xerostomia following pathological conditions like Sjogren's syndrome or head and neck radiotherapy usually lead to tremendous impairment of oral health, speech, and swallowing. The use of systemic drugs to alleviate the symptoms of these conditions has been associated with various adverse effects. Techniques of local drug delivery to the salivary gland have grown enormously to address this problem properly. The techniques include intraglandular and intraductal injections. In this chapter, we will provide a review of the literature for both techniques while incorporating our lab experience in using them.

[Therapy of Sialorrhea with Botulinum Toxin - An Update]

The most important salivary glands are the paired parotid and submandibular glands. Adults produce 1 to 1.5 liters of saliva which are then regularly swallowed. When the act of swallowing is disturbed, salivation occurs. More rarely, the cause can be found in increased saliva production, for example, when caused through medication. Sialorrhea impairs the quality of life substantially and is frequently often socially stigmatizing. Therapy includes conservative measures such as functional dysphagia therapy, oral or transdermal application of anticholinergics, as well as, in selected cases, radiation and surgical measures. Over the last 20 years, local injection of botulinum toxin has been successfully applied in the treatment of this condition. With approval of incobotulinumtoxinA toxin for children and adults, this procedure will become the therapy of choice for chronic sialorrhea. The results of the phase III registration trials have demonstrated high efficacy and good safety of the injection treatment in both children and adults.

Safety of High-Dose Botulinum Toxin Injections for Parotid and Submandibular Gland Radioprotection

Botulinum Toxin injections into salivary glands (SG) up to a total dose of 100 units IncobotulinumtoxinA (IncoA) represent the treatment of choice for sialorrhea. However, BTX might also protect SG against sialotoxic radioligand cancer therapies. The radioligand Actinium-225-PSMA effectively targets Prostate Cancer (PCa) metastases but inevitably destroys SG due to unintended gland uptake. A preliminary case series with regular-dose IncoA failed to reduce SG PSMA-radioligand uptake. We therefore increased IncoA dosage in combination with transdermal scopolamine until a clinically relevant SG PSMA-radioligand uptake reduction was achieved. Ten consecutive men with metastasized PCa refractory to all other cancer therapies received gradually increasing IncoA dosages as part of a compassionate use PSMA-radioligand-therapy trial. The parotid gland received six and the submandibular gland three injection points under ultrasound control, up to a maximum of 30 units IncoA per injection point. A maximum total dose of 250 units IncoA was applied with up to 170 units per parotid and 80 units per submandibular gland. Treatment was well tolerated and all side-effects were non-serious. The most frequent side-effect was dry mouth of mild severity. No dysphagia, facial weakness, chewing difficulties or systemic side-effects were observed. SG injections with IncoA up to a total dose of 250 units are safe when distributed among several injection-points under ultrasound control by an experienced physician. These preliminary findings lay the basis for future trials including BTX as major component for SG protection in established as well as newly emerging radioligand cancer therapies.

A consensus statement on the use of botulinum toxin in pediatric patients

Botulinum toxin has been used in medicine for the past 30 years. However, there continues to be controversy about the appropriate uses and dosing, especially in the pediatric population. A panel of nine pediatric physiatrists from different regions and previous training programs in the United States were nominated based on institutional reputation and botulinum toxin (BoNT) experience. Based on a review of the current literature, the goal was to provide the rationale for recommendations on the administration of BoNT in the pediatric population. The goal was not only to review safety, dosing, and injection techniques but also to develop a consensus on the appropriate uses in the pediatric population. In addition to upper and lower limb spasticity, the consensus also provides recommendations for congenital muscular torticollis, cervical dystonia, sialorrhea, and brachial plexus palsies.

Prolonged Weaning: S2k Guideline Published by the German Respiratory Society

Mechanical ventilation (MV) is an essential part of modern intensive care medicine. MV is performed in patients with severe respiratory failure caused by respiratory muscle insufficiency and/or lung parenchymal disease; that is, when other treatments such as medication, oxygen administration, secretion management, continuous positive airway pressure (CPAP), or nasal high-flow therapy have failed. MV is required for maintaining gas exchange and allows more time to curatively treat the underlying cause of respiratory failure. In the majority of ventilated patients, liberation or "weaning" from MV is routine, without the occurrence of any major problems. However, approximately 20% of patients require ongoing MV, despite amelioration of the conditions that precipitated the need for it in the first place. Approximately 40-50% of the time spent on MV is required to liberate the patient from the ventilator, a process called "weaning". In addition to acute respiratory failure, numerous factors can influence the duration and success rate of the weaning process; these include age, comorbidities, and conditions and complications acquired during the ICU stay. According to international consensus, "prolonged weaning" is defined as the weaning process in patients who have failed at least 3 weaning attempts, or require more than 7 days of weaning after the first spontaneous breathing trial (SBT). Given that prolonged weaning is a complex process, an interdisciplinary approach is essential for it to be successful. In specialised weaning centres, approximately 50% of patients with initial weaning failure can be liberated from MV after prolonged weaning. However, the heterogeneity of patients undergoing prolonged weaning precludes the direct comparison of individual centres. Patients with persistent weaning failure either die during the weaning process, or are discharged back to their home or to a long-term care facility with ongoing MV. Urged by the growing importance of prolonged weaning, this Sk2 Guideline was first published in 2014 as an initiative of the German Respiratory Society (DGP), in conjunction with other scientific societies involved in prolonged weaning. The emergence of new research, clinical study findings and registry data, as well as the accumulation of experience in daily practice, have made the revision of this guideline necessary. The following topics are dealt with in the present guideline: Definitions, epidemiology, weaning categories, underlying pathophysiology, prevention of prolonged weaning, treatment strategies in prolonged weaning, the weaning unit, discharge from hospital on MV, and recommendations for end-of-life decisions. Special emphasis was placed on the following themes: (1) A new classification of patient sub-groups in prolonged weaning. (2) Important aspects of pulmonary rehabilitation and neurorehabilitation in prolonged weaning. (3) Infrastructure and process organisation in the care of patients in prolonged weaning based on a continuous treatment concept. (4) Changes in therapeutic goals and communication with relatives. Aspects of paediatric weaning are addressed separately within individual chapters. The main aim of the revised guideline was to summarize both current evidence and expert-based knowledge on the topic of "prolonged weaning", and to use this information as a foundation for formulating recommendations related to "prolonged weaning", not only in acute medicine but also in the field of chronic intensive care medicine. The following professionals served as important addressees for this guideline: intensivists, pulmonary medicine specialists, anaesthesiologists, internists, cardiologists, surgeons, neurologists, paediatricians, geriatricians, palliative care clinicians, rehabilitation physicians, intensive/chronic care nurses, physiotherapists, respiratory therapists, speech therapists, medical service of health insurance, and associated ventilator manufacturers.

Sialorrhea in Parkinson's Disease

Sialorrhea, or excessive saliva beyond the margin of the lip, is a common problem in many neurological diseases. Previously, sialorrhea has been underrecognized in Parkinson’s disease (PD) patients. Despite this, many patients rank sialorrhea as one of the most debilitating complaints of Parkinson’s disease. Previous treatment for sialorrhea has been suboptimal and has been plagued by significant side effects that are bothersome and can be dangerous in patients with a concurrent neurodegenerative disease. This review sought to review the anatomy, function, and etiology of sialorrhea in PD. It then sought to examine the evidence for the different treatments of sialorrhea in PD, and further examined newer evidence for safety and efficacy in minimally invasive treatment such as botulinum toxin.

Accuracy of unguided and ultrasound guided Coracohumeral ligament infiltrations - a feasibility cadaveric case series

BACKGROUND

Coracohumeral ligament (CHL) thickening, contracture, and fibroplasia have been identified in glenohumeral idiopathic adhesive capsulitis (GHIAC). The CHL is the main structure responsible for the range of motion limitations. Favorable outcomes have been reported with CHL surgical release. Intra-articular glenohumeral joint corticosteroid infiltrations are utilized to disrupt the inflammatory process and reduce pain in GHIAC. The aim of this study was to investigate whether the CHL could be accurately targeted with a periligamentous infiltration.

METHODS

A convenience sample of 12 unembalmed cadaver shoulders (mean age: 74.5 years, range 66-87 years) without evidence of previous injury or surgery were utilized in this exploratory double factor feasibility cadaveric (unguided and ultrasound (US) guided) case series. Two clinicians trained in musculoskeletal infiltration techniques carried out the infiltrations on each shoulder with colored latex. One clinician infiltrated without guidance, the other with US-guidance. The injecting clinicians were blinded to the others infiltration procedure and the order was randomized. An anatomist blinded to the infiltration order performed a shoulder dissection and recorded the infiltrate location. Percentage calculation for accuracy of infiltration and a chi-square evaluation of the difference between unguided and US-guided infiltrations was applied.

RESULTS

An accuracy of 75% was achieved for unguided infiltration and 80% for US-guided infiltration techniques. Chi-squared indicated there was no significant difference (p = 0.82) between the unguided and US-guided techniques.

CONCLUSION

US-guided and unguided infiltrations achieved good accuracy targeting the CHL, suggesting infiltrations can specifically and accurately target the CHL. In vivo investigation using such infiltration techniques are warranted.

Localization of Salivary Glands for Botulinum Toxin Treatment: Ultrasound Versus Landmark Guidance

Background

Sialorrhea is a troublesome symptom in a variety of neurological diseases. Recently, local injection of botulinum toxin into the salivary glands was approved for treatment of sialorrhea, and injection guidance by anatomical landmarks was suggested.

Objective

To compare the accuracy of ultrasound versus previously proposed anatomical landmarks for localizing the salivary glands.

Methods

In a cross-sectional study in 21 adults, landmark positions (LM) of the parotid gland (PG) and the submandibular gland (SG) were identified following published recommendations. The ultrasound position (US) was defined as the position representing the maximum gland thickness. The distance between positions, gland thickness, and optimal injection depth were recorded by US.

Results

Gland thickness differed significantly between LM and US positions (PG, 4 vs. 17.8 mm; P < 0.001; SG, 3.5 vs. 13.6 mm; P < 0.001). The spatial deviation between the recommended LM and identified US positions in the horizontal plane was 21 mm to the posterior direction for the PG and 19.6 mm for the SG. The deviation in vertical orientation was small for both glands; however, there was a positive correlation between the distance from the SG to the mandibular bone with age. The optimal injection depth measured by US was 11.8 mm for the PG and 13.6 mm for the SG. This showed to be positively correlated with the body mass index.

Conclusions

The position of the salivary glands differs from proposed landmarks and depends on the individual age and body weight; therefore, we recommend ultrasound guidance for injection.

Therapy of Sialorrhea with Botulinum Neurotoxin

Botulinum neurotoxin (BoNT) is considered the treatment of choice for various symptoms and diseases such as focal dystonia and focal spasticity. The effects of BoNT on the salivary glands have also been known for years, but their use was limited because of a lack of approval studies. Now the indication of sialorrhea is approved in some countries for incobotulinumtoxinA, such as the USA and Europe, and therapy could also become the treatment of choice. According to the pivotal study, a dose of 100 units of incobotulinumtoxinA, which is divided into the parotid and submandibular glands, is recommended. RimabotulinumtoxinB is approved in the USA only. To define the value of this therapy, we must consider anatomy, physiology, and available therapies. Therapy includes conservative measures such as functional dysphagia therapy, oral or transdermal application of anticholinergics, and, in selected cases, radiotherapy and surgical procedures. A combination of different approaches is optional. On the basis of the evidence and clinical experience, BoNT injections will be the first line of pharmacotherapy for chronic sialorrhea.

Feasibility of Ultrasound-Guided Trigger Point Injection in Patients with Myofascial Pain Syndrome

We compared the feasibility of ultrasound (US)-guided myofascial trigger point (MTrP) injection with that of a blind injection technique following the use of shear wave elastography (SWE) for the measurement of stiffness at the MTrPs in patients with trapezius myofascial pain syndrome (MPS). A total of 41 patients (n = 41) were randomized to either the trial group (n = 21, SWE combined with US-guided injection) or the control group (n = 20, SWE combined with blind injection). At baseline and four weeks, they were evaluated for the manual muscle test (MMT), the range of motion (ROM), pain visual analogue scale (VAS) scores, Shoulder Pain and Disability Index (SPADI) scores and Neck Disability Index (NDI) scores during the abduction, adduction, flexion, extension, external rotation and internal rotation of the shoulder joint. Differences in changes in pain VAS scores, NDI scores and SPADI scores at four weeks from baseline between the two groups reached statistical significance (p = 0.003, 0.012, and 0.018, respectively). US-guided MTrP injection is a more useful modality as compared with a blind injection in patients with MPS.

Clinical implications of aberrant neurovascular structures coursing through the submandibular gland

Background

Variation within the submandibular triangle, including variant paths of facial neurovasculature, could increase risk of neurovascular derangement during submandibular gland (SMG) dysfunction, enlargement, interventions, or removal.

Methods

Frequency of anatomical variants enveloped within or piercing the SMG, including facial artery, vein, or branches of CN VII, were assessed in 70 cadaveric submandibular glands (39M/31F).

Results

Eighteen of 70 SMGs (25.7%) were pierced by at least one aberrant neurovasculature structure: Facial artery most frequently (n = 13), followed by facial vein (n = 2), inferior labial artery and vein (n = 1), and CN VII cervical branch (n = 1). This study demonstrated the high variability of neurovasculature within submandibular parenchyma. These aberrant neurovascular structures, especially facial artery, are in danger of compromise during surgical and other medical procedures on the SMG. To avoid potential neurovascular compromise, ultrasonographic or other imaging is recommended prior to procedures involving the SMG.

A Functional Approach to Posttraumatic Salivary Fistula Treatment: The Use of Botulinum Toxin

This manuscript highlights key aspects regarding the practical use of botulinum toxin for the conservative nonsurgical treatment of a rarely encountered, but significant posttraumatic complication-the parotid salivary fistula. It adds information to the scarce existing literature on the subject. The authors outline the main differences between postoperative and trauma-related parotid injury regarding salivary fistula treatment. A total of 6 patients with trauma-related salivary fistulas have been treated by Abobotulinum toxin A injections over the course of 5 years. The technique is detailed, describing the doses used in the presence of parenchyma and duct injuries, the location and number of injection points in relation to the wound pattern. The results were favorable, leading to the healing of the salivary fistulas in all patients, with 1 injection session, without additional conservative treatment. In our experience, the use of botulinum toxin is of great benefit for treating salivary fistulas in a traumatic context.

Treatment of sialorrhoea with repeated ultrasound-guided injections of botulinum toxin A into the parotid and submandibular glands

Botulinum toxin injections are useful in patients with refractory sialorrhoea although the optimum treatment protocol and its efficacy over a long period of follow up are controversial. The aim of our prospective study was to examine the efficacy and complications of a protocol of repeated ultrasound-guided botulinum toxin injections of fixed doses at a tertiary children's hospital. A total of 79 procedures were done in 34 patients who were followed up for two years. The overall complication rate was 3%. The outcome measures considered included the Drooling Frequency Severity Scale (DFSS), visual analogue scale (VAS), and carers' assessments of the reduction in drooling. Our study highlighted two types on non-responders (primary and secondary) of which 3/34 required definitive surgical management. In summary, this study shows that a protocol of repeated injections of fixed doses of botulinum toxin A, while not beneficial in all cases, is a potentially valuable option for the safe and effective treatment of sialorrhoea in children.