Botulinum toxin treatment of salivary fistulas following parotidectomy: follow-up results

Comparative Analysis of Fistula Development After Parotid Gland Surgery: Lateral Parotidectomy Versus Extracapsular Dissection Technique

PURPOSE

The primary objective of this study was to explore the potential disparity in postoperative fistula occurrence rates between patients who undergo (partial) lateral parotidectomy and those who undergo the extracapsular dissection technique for the management of benign parotid gland tumours.

METHODS

A consecutive series of 363 patients treated with (partial) lateral parotidectomy and extracapsular dissection technique for benign parotid gland tumours at one tertiary centre between 2018 and 2022 were included. To evaluate the impact of the surgical technique and possible other risk factors (tumour location, tumour size, Body Mass Index, age, smoking, diabetes mellitus, arterial hypertension) for the development of fistulas, multivariate logistic regression analyses using backward lection were applied to estimate odds ratios (ORs) and 95%-confidence intervals (CIs).

RESULTS

In 363 patients, 21 patients (5.8%) developed a fistula. Patients who underwent (partial) lateral parotidectomy had three times higher chance of developing a fistula compared to patients who were operated using the extracapsular dissection technique (ORadjusted = 2.6, 4.1% vs. 12.5%, p = 0.044). In the multivariate analyses, no other risk factors for the development of fistulas were statistically significant in this cohort. The incidence of facial nerve paralysis was not significantly different between the extracapsular dissection and lateral parotidectomy group (5/73 = 6.8% vs. 11/290 = 3.8%, p = 0.333).

CONCLUSION

Fistulas occur more often in patients treated by means of a (partial) lateral parotidectomy approach compared to patients treated using the extracapsular dissection technique. Therefore, surgeons should be vigilant about postoperative fistula risks in lateral parotidectomy and consider preventive measures.

The Potential Therapeutic Effects of Botulinum Neurotoxins on Neoplastic Cells: A Comprehensive Review of In Vitro and In Vivo Studies

A systematic review of the literature found fifteen articles on the effect of a botulinum toxin on neoplastic cell lines and eight articles on in vivo neoplasms. The reported in vitro effects rely on high doses or the mechanical disruption of cell membranes to introduce the botulinum neurotoxin into the cell cytoplasm. The potency of the botulinum neurotoxin to intoxicate non-neuronal cells (even cell lines expressing an appropriate protein receptor) is several orders of magnitude lower compared to that to intoxicate the primary neurons. The data suggest that the botulinum toxin disrupts the progression of cancer cells, with some studies reporting apoptotic effects. A majority of the data in the in vivo studies also showed similar results. No safety issues were disclosed in the in vivo studies. Limited studies have suggested similar anti-neoplastic potential for the clostridium difficile. New modes of delivery have been tested to enhance the in vivo delivery of the botulinum toxin to neoplastic cells. Careful controlled studies are necessary to demonstrate the efficacy and safety of this mode of anti-neoplastic treatment in humans.

Botulinum Toxin Treatment for Cancer-Related Disorders: A Systematic Review

This systematic review investigates the effect of botulinum neurotoxin (BoNT) therapy on cancer-related disorders. A major bulk of the literature is focused on BoNT's effect on pain at the site of surgery or radiation. All 13 published studies on this issue indicated reduction or cessation of pain at these sites after local injection of BoNTs. Twelve studies addressed the effect of BoNT injection into the pylorus (sphincter between the stomach and the first part of the gut) for the prevention of gastroparesis after local resection of esophageal cancer. In eight studies, BoNT injection was superior to no intervention; three studies found no difference between the two approaches. One study compared the result of intra-pyloric BoNT injection with preventive pyloromyotomy (resection of pyloric muscle fibers). Both approaches reduced gastroparesis, but the surgical approach had more serious side effects. BoNT injection was superior to saline injection in the prevention of esophageal stricture after surgery (34% versus 6%, respectively, p = 0.02) and produced better results (30% versus 40% stricture) compared to steroid (triamcinolone) injection close to the surgical region. All 12 reported studies on the effect of BoNT injection into the parotid region for the reduction in facial sweating during eating (gustatory hyperhidrosis) found that BoNT injections stopped or significantly reduced facial sweating that developed after parotid gland surgery. Six studies showed that BoNT injection into the parotid region prevented the development of or healed the fistulas that developed after parotid gland resection-parotidectomy gustatory hyperhidrosis (Frey syndrome), post-surgical parotid fistula, and sialocele. Eight studies suggested that BoNT injection into masseter muscle reduced or stopped severe jaw pain after the first bite (first bite syndrome) that may develop as a complication of parotidectomy.

Risk factors for sialocele after parotidectomy: Does tumor size really matter?

OBJECTIVE

Sialocele that develops after parotid surgery often prolongs the treatment period and stresses both the surgeon and patient. The extent of surgery and tumor size are known to be associated with sialocele occurrence. We investigated the incidence of post-parotidectomy sialocele and the associated risk factors, with a focus on tumor size.

METHODS

We retrospectively reviewed the medical records of 172 patients who underwent parotidectomy between January 2013 and May 2020 at Haeundae Paik Hospital, Inje University of Korea. We stratified patients into those with and without sialocele (fluid collection in the operative bed). We compared clinical data, patient demographics, and surgical details; we identified risk factors for sialocele development after parotid surgery.

RESULTS

Seventeen patients were diagnosed with post-parotidectomy sialocele (9.88%; 17/172). Univariate logistic regression revealed that the male sex, deep lobe tumor location, and large tumor size were significantly associated with postoperative sialocele (p = 0.015, 0.009, and 0.016, respectively). We subjected these parameters to multivariate analyses; the odds ratios were 3.70, 3.58, and 2.34, respectively. Receiver operating characteristic curve analyses showed that a tumor size > 2.50 cm was the optimal cutoff in terms of predicting post-parotidectomy sialocele.

CONCLUSION

Male sex, a tumor in the deep lobe, and large tumor size were strongly associated with increased risk for sialocele after parotidectomy. Tumor size > 2.50 cm serves as the cutoff identifying patients likely to experience sialocele after parotid surgery.

Guidelines for the Use of Botulinum Toxin in Otolaryngology From the Korean Society of Laryngology, Phoniatrics and Logopedics Guideline Task Force

The Korean Society of Laryngology, Phoniatrics and Logopedics created a task force to establish clinical practice guidelines for the use of botulinum toxin (BT) in otolaryngology. We selected 10 disease categories: spasmodic dysphonia, essential vocal tremor, vocal fold granuloma, bilateral vocal fold paralysis, Frey's syndrome, sialocele, sialorrhea, cricopharyngeal dysfunction, chronic sialadenitis, and first bite syndrome. To retrieve all relevant papers, we searched the CORE databases with predefined search strategies, including Medline (PubMed), Embase, the Cochrane Library, and KoreaMed. The committee reported 13 final recommendations with detailed evidence profiles. The guidelines are primarily aimed at all clinicians applying BT to the head and neck area. In addition, the guidelines aim to promote an improved understanding of the safe and effective use of BT by policymakers and counselors, as well as in patients scheduled to receive BT injections.

Botulinum toxin A in dentistry and orofacial surgery: an evidence-based review - part 1: therapeutic applications

Objective An evidence-based review on the safety and efficacy of botulinum toxin type-A (BoNTA) in orofacial conditions, focusing on the therapeutic applications and role of BoNTA as an adjuvant treatment.Data source and selection Data was collected using PubMed (Medline), Cochrane Library of Systematic Reviews and Cochrane Central Register of Controlled Trials electronic databases. Having satisfied the search parameters, 32 studies for therapeutic applications and 26 for BoNTA as an adjunctive treatment were included. The quality of relevant studies was assessed using the Best Evidence Topics (BETs) Critical Appraisal Tool.Data extraction The highest level of evidence (LOE) behind BoNTA safety and efficacy was for wound healing and scar management in the orofacial surgery context, where BoNTA was presented as an adjunctive modality. Level-I evidence was controversial for temporomandibular disorders and bruxism. However, it showed promising results for painful temporomandibular disorders of myogenic origin refractory to conservative therapies, and to decrease muscle contraction intensity in sleeping bruxism. There was only one level-II study for persistent recurrent aphthous stomatitis. Data showed limited level-III evidence for orofacial pain conditions (temporomandibular joint recurrent dislocation and pain, burning mouth syndrome or atypical odontalgia), oral cancer complications, or as an adjuvant to maxillofacial and orthognathic surgeries. Benefits of BoNTA in prosthodontics had weak level-IV evidence. No evidence was found among the periodontology field.Conclusion There is growing evidence to support the safety and efficacy of BoNTA in the investigated orofacial pathological conditions, with high levels of satisfaction from the patient and clinician perspective. However, there are some inconsistencies and limited high-quality evidence available. Well-designed controlled clinical trials are necessary to evaluate long-term safety, efficacy and cost-effectiveness before BoNTA is widely adopted with irrefutable evidence-based clinical guidelines.

Botulinum toxin in cancer therapy-current perspectives and limitations

Abstract

Different serotypes of botulinum toxins (BoNTs) act upon different types of SNARE proteins. This property is used in aesthetic medicine to treat certain eye disorders such as crossed eyes (strabismus) and uncontrolled blinking (blepharospasm), to treat muscle spasms or movement disorders, and, for the two last decades, more and more often, to provide support in cancer therapy, especially so as to obtain analgesic effects upon spastic conditions. The limited literature data also suggests that the addition of BoNTs to the culture of cancer cell lines reduces cell growth, and mitotic activity, and promotes their apoptosis. BoNTs have several advantages that can be emphasized: BoNTs act on both perfusion and oxygenation; moreover, BoNTs are considered to be safe and free of systemic side effects upon administration. Recently, advances in molecular biology techniques have allowed a wide variety of novel BoNT constructs with alternative functions. These constructs could be assessed as potential new classes of anti-cancer drugs. This creates new potential perspectives in the wider use of non-toxic modified BoNT constructs in cancer therapy. In the light of the mentioned premises and existing literature reports, the aim of this review is to summarize current data and reports considering BoNT use in cancer therapy.

Key points

•Botulinum toxin (BoNTs) may be useful in cancer treatment.

•Botulinum toxin can serve as an analgesic after cancer radiotherapy.

•Botulinum toxin has the ability to inhibit tumor growth and promote apoptosis of neoplastic cells.

Intraoperative botulinum toxin injection for superficial partial parotidectomy: A prospective pilot study

OBJECTIVES

Sialocele and salivary fistula are not serious but troublesome complications after parotidectomy. Various modalities have been introduced to prevent postoperative saliva-related complications. However, clinical trials assessing the prophylactic use of botulinum toxin (BTX) for parotidectomy have not been conducted yet. Herein, we report a pilot study investigating the safety and efficacy of intraoperative BTX (iBTX) injection in partial superficial parotidectomy (PSP).

PARTICIPANTS

Patients with benign parotid tumour were prospectively recruited for this clinical trial from 2017 to 2019. The study participants underwent PSP with iBTX injection. We retrospectively reviewed the clinical information of all the consecutive patients who underwent PSP without iBTX from 2013 to 2019. These patients were divided into two groups: the iBTX group (n = 36) and the control group (n = 54).

RESULTS

Permanent facial palsy was not observed in either group. Two patients (3.7%) had transient marginal palsy in the control group but none had it in the iBTX group. The incidence of sialocele was significantly lower in the iBTX group than in the control group (2.8% vs. 20.4%, P < .05). Although the incidence of salivary fistula was lower in the iBTX group than in the control group (0% vs. 7.4%), no significant difference was determined between the two groups (P = .147). Total drainage volume was significantly lower in the iBTX group than in the control group (55.0 mL vs. 116.6 mL, P < .001).

CONCLUSIONS

iBTX injection may be safe and effective in reducing sialocele and postoperative drainage in PSP. It might be a useful option to prevent saliva-related complications after PSP.

Non-aesthetic uses of botulinum toxin in the head and neck

INTRODUCTION

The use of botulinum toxin in the specialty of aesthetic surgery in the head and neck is well known. However, it has also been used for other conditions affecting the head and neck, and in recent years its use, as well as the number of relevant applications, has expanded enormously.

REVIEW

This article presents a summary of the current range of uses in the laryngeal, pharyngeal, cervical, oromandibular and facial muscles and salivary glands. We highlight particular conditions focusing on dystonia (laryngeal, craniocervical, oromandibular and cervical), multiple system atrophy, migraines, facial nerve palsy, post-laryngectomy, cricopharyngeal dysphagia, Zenker's diverticulum, retrograde cricopharyngeal dysfunction disorder, sialorrhea and gustatory sweating (Frey's syndrome).

CONCLUSION

This article should aid the ear, nose and throat surgeon garner knowledge about the range of uses for botulinum toxin in the head and neck.

Management of parotid fistula and Frey's syndrome with Botulinum neurotoxin type A

The common cause of parotid fistula is parotid gland surgery and is frequently due to injury to the gland rather than to the duct. The frequency of postparotidectomy fistula is 14%. Other causes include facial trauma, congenital anomalies of the parotid gland, malignancies originating from the parotid gland and infections. Although there are several options for the treatment of parotid fistula and Frey's syndrome, very few treatment options are deemed optimal. The use of Botulinum A neurotoxin as a conservative method of treatment for parotid fistula and Frey's syndrome is a recent and evolving concept.

Botulinum toxin A is an effective therapeutic tool for the management of parotid sialocele and fistula: A systematic review

OBJECTIVES

In the management of parotid sialocele and fistula, various conservative and surgical methods have been described. Some studies have described the use of Botulinum toxin A (Botox A) for the management of parotid sialocele and fistula. This is a less invasive and potentially equally effective option. We therefore conducted a systematic review on the current body of literature relating to this specific use of Botox A.

METHODS

A search strategy was conducted in July 2019 using the following electronic databases: Cochrane Database of Systematic Reviews, EMBASE, Google Scholar, PubMed, Scopus, and Web of Science. A search of all articles from inception until 31 August 2019 was performed.

RESULTS

Literature searches of electronic databases identified 67 articles eligible for review, of which 15 fulfilled all criteria. These studies were small and in total only 47 patients were included. The majority of sialoceles and fistulas presented as a complication of surgery (77%) with the remaining cases occurring as a result of trauma. The typical age at presentation was between 32 and 88 years of age (mean age of 52 years). All patients were initially treated with and failed other conservative measures. Botox A injection was considered as a final conservative treatment option. The toxin was administered percutaneously in all cases of parotid sialocele and fistula. Dosage of Botox ranged from 10 to 200 units with majority of patients (58%) requiring only one injection. The overall success rate for patients treated with Botox A injections ranged between 70 and 100% for parotid sialoceles and fistulas.

CONCLUSION

Botox A injections are successful in the treatment of parotid sialoceles and fistulas and should be considered before the use of invasive conventional options. Further studies with larger numbers are needed to ratify this recommendation. Success rate for patients, treated with Botox A injection was between 70 and 100% for parotid sialocele and fistula. Patients who failed initial treatment with Botox A were re-administered with Botox A and eventually resolved.

Botulinum Neurotoxins and Cancer-A Review of the Literature

Botulinum neurotoxins (BoNT) possess an analgesic effect through several mechanisms including an inhibition of acetylcholine release from the neuromuscular junction as well as an inhibition of specific pain transmitters and mediators. Animal studies have shown that a peripheral injection of BoNTs impairs the release of major pain transmitters such as substance P, calcitonin gene related peptide (CGRP) and glutamate from peripheral nerve endings as well as peripheral and central neurons (dorsal root ganglia and spinal cord). These effects lead to pain relief via the reduction of peripheral and central sensitization both of which reflect important mechanisms of pain chronicity. This review provides updated information about the effect of botulinum toxin injection on local pain caused by cancer, painful muscle spasms from a remote cancer, and pain at the site of cancer surgery and radiation. The data from the literature suggests that the local injection of BoNTs improves muscle spasms caused by cancerous mass lesions and alleviates the post-operative neuropathic pain at the site of surgery and radiation. It also helps repair the parotid damage (fistula, sialocele) caused by facial surgery and radiation and improves post-parotidectomy gustatory hyperhidrosis. The limited literature that suggests adding botulinum toxins to cell culture slows/halts the growth of certain cancer cells is also reviewed and discussed.

Intraductal Salivary Gland Infusion With Botulinum Toxin

Background

Administration of botulinum toxin through intraductal salivary infusion may decrease the risks of percutaneous needle injection and improve delivery to permeate the entire gland parenchyma.

Methods

The safety of intraductal salivary gland infusion was tested with prospective evaluation of two patients using interviews, clinical examination, and pressure measurement during infusion. Retrospective chart review of two subsequently treated patients assessed treatment of a parotid-cutaneous fistula and sialorrhea.

Results

No complications were identified in the safety study. Pressure changes during infusion supported the concept of botulinum neurotoxin delivery to permeate the gland. Patient-assessed success was subjectively reported as a reduction in the parotid-cutaneous output "by 95%" and the sialorrhea "by 90%" at 2-week follow-up.

Conclusions

The intraductal route of botulinum toxin delivery to salivary glands was without complication and was effective in two patients treated therapeutically. Pressure measurements during infusion may be helpful to direct treatment.

Level of Evidence

4.

Botulinum Toxin for Side-Effect Management and Prevention of Surgical Complications in Patients Treated for Head and Neck Cancers and Esophageal Cancer

The management of head and neck cancers (HNC) and esophageal cancer (EC) is complex and often involves multiple modalities of treatment, including chemotherapy, radiation therapy, and surgery. The side effects associated with these therapies and disease processes are extensive. A literature review was performed to evaluate the use of botulinum toxin as an intervention for side-effect management in patients with HNC and EC. Specific adverse events reviewed included salivary function (hypersalivation, fistula, hyposalivation) and gastrointestinal motility (esophageal stricture, delayed gastric emptying after esophagectomy). Published results demonstrate an improvement in hypersalivation and, when botulinum toxin was used as an adjunct to treatment, a reduction in symptoms associated with salivary fistula, or an inappropriate communication between the salivary gland and the skin that causes the leakage of saliva through the skin. Positive effects were also demonstrated in regard to esophageal stricture and equivalent effects in the management of gastric emptying to prevent complications after esophagectomy when compared to currently available interventions. However, the potential for increased symptoms associated with botulinum toxin injection related to its use in the management of gastric secretions was noted in one of the studies reviewed.

Management and Follow-up Results of Salivary Fistulas Treated With Botulinum Toxin

OBJECTIVES/HYPOTHESIS

Salivary fistulas are a common minor complication of parotid surgery. botulinum toxin has repeatedly been reported to be an adequate treatment of this entity. To date, there is little scientific evidence for clinical decision making after appearance of a salivary fistula.

STUDY DESIGN

Retrospective chart analysis of 16 patients who had been treated with botulinum toxin for salivary fistula.

METHODS

All patients who had been treated for salivary fistula at a tertiary referral hospital from 2010 to 2016 were included. Patient files were used to obtain characteristics of patients, treatment, and follow-up.

RESULTS

Sixteen patients with salivary fistula received 27 injections of botulinum toxin. Nine patients required one injection for the fistula to heal, five patients needed two injections, and one patient needed three and four injections, respectively. No patient underwent additional surgery or radiotherapy. We observed no adverse effects in any patient treated with botulinum toxin.

CONCLUSIONS

In most cases of salivary fistula, injections of botulinum toxin are a valid treatment. If the initial injection is not successful, injections may be repeated once. Otherwise, revision surgery should be considered. In general, treatment with botulinum toxin should be commenced in an earlier stage and with higher dosages.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:403-408, 2019.

Botulinum toxin therapy: functional silencing of salivary disorders

Botulinum toxin (BTX) is a neurotoxic protein produced by Clostridium botulinum, an anaerobic bacterium. BTX therapy is a safe and effective treatment when used for functional silencing of the salivary glands in disorders such as sialoceles and salivary fistulae that may have a post-traumatic or post-operative origin. BTX injections can be considered in sialoceles and salivary fistulae after the failure of or together with conservative treatments (e.g. antibiotics, pressure dressings, or serial aspirations). BTX treatment has a promising role in chronic sialadenitis. BTX therapy is highly successful in the treatment of gustatory sweating (Frey's syndrome), and could be considered the gold standard treatment for this neurological disorder.

Transdermal scopolamine for the prevention of a salivary fistula after parotidectomy

Our aim was to investigate whether perioperative transdermal application of scopolamine could help to prevent fistulas after parotidectomy, and to this end we retrospectively studied the records of all patients (n=645) who had benign parotid tumours treated by partial parotidectomy between 2011 and 2016. We found that scopolamine led to a significant decrease in the incidence of salivary fistulas from 54/371(15%) in the group not given it to 10/274 (4%) in the group given it (p<0.0001). The "number needed to treat" was 9.17. There was a relatively low incidence of all adverse effects after scopolamine. Our results are encouraging. Thorough consideration of the contraindications and a knowledge of the potential adverse effects are crucial for its successful implementation.