Case-tailored indicated extracapsular dissection versus "one-size-fits-all" nerve dissection: Has the bet been won?

OBJECTIVE

The aim of the study was to trace the development of surgical therapy in a large cohort, examine its changes at one single institution that has been specializing in salivary gland pathologies over the last 22 years, and to determine the extent to which a possible shift in the surgical therapy of parotid benign tumors towards less radical methods was correlated with a change in the incidence of facial palsy and Frey's syndrome.

STUDY DESIGN

Retrospective clinical study.

METHODS

A retrospective evaluation of the records of all patients treated for benign parotid tumors at a tertiary referral center between 2000 and 2022 was carried out. Surgical methods were classified into four groups: extracapsular dissection, partial superficial parotidectomy, superficial parotidectomy and complete parotidectomy.

RESULTS

A total of 4037 patients were included in the study. Our analysis demonstrated an increase in the total number of parotidectomies for benign lesions from 71 (2000) to 298 (2022), mostly due to the increase in extracapsular dissections (from 9 to 212). The increased performance of less radical surgery was associated with a significantly decreased incidence of perioperative complications.

CONCLUSIONS

Our study showed that the increased performance of less radical surgery was associated with better functional outcomes over the years.

Prospective study on complications using different techniques for parotidectomy for benign tumors

OBJECTIVES

Long-term prospective studies on procedure-related complications after parotid surgery for benign neoplasms (BNs) are scarce. This is the first prospective study on the use of extracapsular dissection (ECD) for BNs, and it aimed to examine the incidence of postoperative complications after parotid surgery for BN.

METHODS

We collected data obtained in a prospective study of parotidectomy for BN at a university hospital and analyzed the transient and long-term complications.

RESULTS

The incidence rates of transient facial palsy immediately and 18 months after surgery were 15.0% and 3.7%, respectively. The rates of immediate postoperative facial palsy in patients who underwent ECD, partial superficial, superficial, and total parotidectomy were 5.8%, 29.3%, 20.0%, and 44.1%, respectively. Significant risk factors for facial palsy included multiple and larger lesions as well as surgery duration and extension.

CONCLUSIONS

Postoperative facial palsy remains a common complication after parotidectomy for BN and is associated with the extent of parotidectomy, presence of multiple neoplasms, and operative duration. The results of this study showed that ECD could be a safe technique for avoiding facial palsy. Level of Evidence: 2.

Surgical interventions for management of benign parotid tumors: A systematic review and network meta-analysis

The impact of the extent of parotid surgery on postoperative complications has long been considered a topic of controversy. The aim of the current network meta-analysis (NMA) is to answer the following questions: (1) Does the extent of surgical resection of benign parotid tumors increase the risk of postoperative complications? (2) What is the best surgical intervention for treatment of benign parotid tumors that can provide an acceptable balance between tumor recurrence rate and other postoperative complications? A comprehensive search on PubMed, Embase, Scopus, and Cochrane library was conducted to identify the eligible studies. The outcome was the incidence of tumor recurrence, facial nerve weakness (temporary [TFW] or permanent [PFP]), Frey's syndrome (FS), sialocele, and salivary fistula. The Bayesian network meta-analysis (NMA) accompanied by a random effect model and 95% credible intervals (CrI) were calculated using the GeMTC R package. Forty-four studies with a total of 7841 participants were included in the current NMA comparing five surgical interventions, namely enucleation, extracapsular dissection (ECD), partial superficial parotidectomy (PSP), superficial parotidectomy (SP), and total parotidectomy (TP). Enucleation showed the highest recurrence rate compared to ECD, SPS, SP, and TP. No statistical differences were observed concerning the recurrence rate when ECD, PSP, SP, and TP were compared together. There was an increased incidence of TFW and FS with the increase in the extent of parotid resection, while no significant difference was found when comparing enucleation with ECD and PSP. SP showed the highest incidence of PFP, and salivary fistula compared to ECD, PSP, and TP. The tumor recurrence rates in enucleation, ECD, PSP, SP, and TP were 14.3%, 3.6%, 3.7%, 2.8%, and 1.4%, respectively. The current NMA demonstrated that the risk of TFW and FS increases with the increase in the extent of parotid resection and that ECD and PSP can be considered the treatment of choice for benign parotid tumors, as both provide an acceptable balance between the incidence of tumor recurrence and facial nerve dysfunction.

Frey's syndrome: A review of the physiology and possible role of neurotrophic factors

OBJECTIVES

Frey's syndrome (FS) describes the phenomenon of gustatory sweating and is a cause of significant social embarrassment for sufferers. It has been attributed to aberrant growth of parasympathetic salivatory fibers in the auriculotemporal nerve toward overlying sweat glands. However, the exact mechanism behind this growth is unknown. This review aims to expand and elucidate the theory of aberrant regeneration in FS.

METHODS

A review of the recent literature on nerve regeneration was conducted in order develop further insights into the etiology of both adult onset and pediatric FS.

RESULTS

Neurturin, a neurotrophic factor released by both salivary and sweat glands, was identified as a possible key player in the etiology of FS.

CONCLUSION

Further research into the role of neurturin could help to elucidate the pathogenic mechanisms underlying the condition and might reveal neurturin to be a potential target for pharmacological intervention.

LEVEL OF EVIDENCE

NA (Basic Science Review).

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.

Acellular dermal matrix for prevention of Frey's syndrome after superficial parotidectomy of benign tumors

PURPOSE

To evaluate: 1) the efficacy of acellular dermal matrix (ADM) to prevent Frey's syndrome (FS) after superficial parotidectomy of benign tumors. 2) the effect of different follow-up intervals on the incidence of FS.

METHODS

Fifty-five patients with benign parotid gland tumors underwent superficial parotidectomy were divided into two groups: Non-ADM group (n = 31, 56.3%) and ADM group (n = 24, 43.6%). The primary outcomes measure was the incidence of FS. The secondary outcomes were surgical site depression, infection, salivary sialocele, and salivary fistula. Subjective FS was evaluated using a clinical questionnaire submitted via WeChat at 3, 6, 12, 18, 24, and 32 months postoperatively. Objective FS was evaluated using Minor starch-iodine test at 6 and 12 months postoperatively.

RESULTS

There was a statistically significant difference in the incidence of subjective and objective FS when ADM compared with Non-ADM groups (P<0.05). The respective incidence of subjective FS at 3, 6, 12, 18, 24, and 32 months was 4.2%, 8.3%,20.8%, 20.8%, 20.8%, 20.8% in ADM group and 3.2%, 9.7%, 29%, 38.7%, 45.2% in Non-ADM group. The incidence of objective FS after 6 and 12 months was 4.2%, 8.3% in ADM group and 8.3% (2/24), 38.7% (12/31) in Non-ADM group respectively. Five patients in ADM group and 1 patient in Non-ADM group developed sialocele, and all patients resolved with conservative management. Surgical site depression was significantly higher in the Non-ADM group (15/31) compared with (5/24) in ADM (P=0.049). No cases of immune rejection, infection, hematoma, or salivary fistula were observed in ADM group.

CONCLUSIONS

The current study demonstrated that 1) ADM could reduce the incidence of FS in the patients undergoing superficial parotidectomy. 2) the peak onset of about 18 months appear to be acceptable follow-up for the development of FS.

Cross-sectional study on the occurrence of Frey's syndrome following superficial parotidectomy or extracapsular dissection

BACKGROUND

Most studies that examine postoperative outcomes after parotidectomy in patients with benign parotid gland tumors are based on retrospective chart reviews. Data about long-term results in patients with parotid gland surgery with patient contact are still sparsely published.

METHODS

During the period of 1960-2005, a total of 127 patients underwent either extracapsular dissection (ECD) or superficial parotidectomy (SP) and were available for interview. Patients were questioned about their postoperative outcome after parotid gland surgery.

RESULTS

The mean follow-up was 21.5 years. A total of 42 and 85 patients underwent ECD and SP, respectively. No significant differences were observed in the rates of permanent facial paralysis (SP 1.2% vs. ECD 7.1%; p = 0.1053) or recurrence (SP 4.7% vs. ECD 11.9%; p = 0.1557), and Frey's syndrome was diagnosed only after SP (10.6% vs. 0% after ECD, p = 0.0293). Frey's syndrome was detected more often compared to retrospective chart analysis.

CONCLUSION

We conclude that Frey's syndrome is underdiagnosed after SP without standardized follow-up examinations. Long-term follow-up should be applied to detect and treat gustatory sweating.

Parotid pleomorphic adenomas: Factors influencing surgical techniques, morbidity, and long-term outcome relative to the new ESGS classification in a retrospective study

PURPOSE

To assess long-term results after treatment of parotid pleomorphic adenomas (PPAs) with different surgical techniques, standardized according to the European Salivary Gland Society (ESGS) classification system.

METHODS

We analyzed ESGS categories, occurrence of facial nerve paresis (FNP), Frey's syndrome, histopathology, and recurrences. Surgical modalities were compared, differentiating techniques with and without facial nerve dissection. A strict protocol ensured a postoperative follow-up-period of more than 7 years.

RESULTS

205 patients were included. A complete follow-up was possible in 138 patients, 77 of whom underwent extracapsular dissection (ED) and 61 of whom had other surgical modalities (OSMs). ESGS categories correlated with the extent of surgery, significantly with the risk for FNP and Frey's syndrome, but not with recurrences. Recurrences did not differ significantly between ED and OSMs, whereas the risks for FNP (p < 0.001 each) and Frey's syndrome (p = 0.000) were significantly higher after OSMs in comparison with ED. Young women with a stroma-rich (myxoid) tumor subtype appear to have the greatest risk for recurrences.

CONCLUSION

ED is the treatment of choice for PPAs, if possible, resulting in similar recurrence rates but significantly fewer comorbidities in comparison with more extensive surgery. After the treatment of PPAs, a long-term follow-up is needed, including imaging.

The preventive effect of decellularized pericardial patch against Frey's syndrome following the superficial parotidectomy

PURPOSE

This study aimed to investigate the feasibility of adopting the ThormalGEN surgical patch (a porcine decellularized pericardial patch) in the superficial parotidectomy to prevent postoperative Frey's syndrome in patients with benign parotid tumor.

MATERIALS AND METHODS

A total of 59 patients with benign parotid tumor undergoing superficial parotidectomy between April 2016 and January 2017 were enrolled, and divided into the ThormalGEN group (n = 37) and the control group (n = 22) based on their willingness to have the ThormalGEN surgical patch used in the superficial parotidectomy. At 6 months postoperation, the incidences of postoperative complications and Frey's syndrome were assessed by subjective assessment (patient self-assessment) and objective assessment (starch-iodine test), respectively. The risk factor of Frey's syndrome was analyzed by the multivariate logistic regression model.

RESULTS

The starch-iodine test, for objective assessment, showed that the ThormalGEN group had a significantly lower incidence of Frey's syndrome than the control group (8.11% vs. 40.91%, p = 006). However, in the patient self-assessment, there was no significant difference in the incidence of Frey's syndrome between groups (8.11% [3/37] vs. 13.64% [3/22], p = 0.4968). The incidences of postoperative complications were not significantly different between group (all p > 0.05). Two patients (5.41%) in the ThormalGEN group had salivary fistula. Multivariate logistic regression analysis showed that the ThormalGEN group had a significantly lower risk of Frey's syndrome than the control group (odds ratio = 0.11, 95% confidence interval = 0.02-0.51, p < 0.01).

CONCLUSION

These results suggest that the ThormalGEN surgical patch can effectively reduce the incidence of Frey's syndrome following superficial parotidectomy in patients with benign parotid tumor, and that this patch has a good safety and biocompatibility profile.

Post Herpetic Frey's Syndrome

Frey's syndrome is characterized by unilateral sweating and flushing of the skin in the area of the parotid gland, occurring during meal, or on salivary stimulation. It is a common complication following surgery/injury in the parotid gland region/temporomandibular joint surgery; however, very few cases have been reported of its occurrence following herpetic infection. It is important for the clinician to recognize its unusual symptoms as early as possible to prevent its potential negative social and psychological effect on the patient. It is diagnosed on clinical presentation and confirmed by objective testing methods. The treatment ranges from topical application of glycopyrrolate to local injections of botulinum toxin and lastly to surgical intervention. An interesting case of Frey's syndrome is presented in a young patient having the previous history of herpes zoster infection, which was diagnosed clinically and confirmed by starch-iodine test and was successfully treated with topical application of glycopyrrolate.

Frey's syndrome after superficial parotidectomy: role of the sternocleidomastoid muscle flap: a prospective nonrandomized controlled trial

BACKGROUND

The prevalence of Frey's syndrome (FS) after superficial parotidectomy in correlation to the sternocleidomastoid muscle flap (SCMMF) interposition is analyzed.

METHODS

A prospective nonrandomized controlled multicenter trial included 130 patients. During superficial parotidectomy, SCMMF was dissected, if excised specimens' volume exceeded 25 mL (SCMMF group). Follow-up examinations took place after 6, 12, and 24 months and included a Minor's test.

RESULTS

SCMMF was dissected in 30 (23.1%) patients. A total of 104, 80, and 68 patients completed the 1st, 2nd, and the 3rd follow-up, respectively. FS was detectable with nonvarying prevalence (46.3%, 45.6%, and 43.4%, respectively) during follow-up. The prevalence was higher in the SCMMF group (59.9%) than in the non-SCMMF group (41.8%; P = .92). The sweating area increased during follow-up (P = .12). Overall, 89.5% of patients characterized FS as not disturbing after 2 years.

CONCLUSIONS

FS occurred with a steady and high prevalence after superficial parotidectomy. In particular, SCMMF did not lower the risk of FS.

Botulinum toxin the poison that heals: A brief review

Botulinum neurotoxins, causative agents of botulism in humans, are produced by Clostridium botulinum, an anaerobic spore-former Gram-positive bacillus. Botulinum neurotoxin poses a major bioweapon threat because of its extreme potency and lethality; its ease of production, transport, and misuse; and the need for prolonged intensive care among affected persons. This paper aims at discussing botulinum neurotoxin, its structure, mechanism of action, pharmacology, its serotypes and the reasons for wide use of type A, the various indications and contraindications of the use of botulinum neurotoxin and finally the precautions taken when botulinum neurotoxin is used as a treatment approach. We have searched relevant articles on this subject in various medical databases including Google Scholar, PubMed Central, ScienceDirect, Wiley Online Library, Scopus, and Copernicus. The search resulted in more than 2669 articles, out of which a total of 187 were reviewed. However, the review has been further constricted into only 54 articles as has been presented in this manuscript keeping in mind the page limitation and the limitation to the number of references. A single gram of crystalline toxin, evenly dispersed and inhaled, can kill more than one million people. The basis of the phenomenal potency of botulinum toxin (BT) is enzymatic; the toxin is a zinc proteinase that cleaves neuronal vesicle-associated proteins responsible for acetylcholine release into the neuromuscular junction. A fascinating aspect of BT research in recent years has been the development of the most potent toxin into a molecule of significant therapeutic utility. It is the first biological toxin which is licensed for the treatment of human diseases. The present review focuses on both warfare potential as well as medical uses of botulinum neurotoxin.

Efficacy and safety of botulinum toxin type A for treatment of Frey's syndrome: evidence from 22 published articles

Frey’s syndrome (FS) is an unavoidable sequela following the surgery of the parotid gland. Although several treatment methods are available, their efficacy is short term or accompanied by unacceptable complications. In the past two decades, botulinum toxin type A (BTXA) has been widely used to treat FS. Although several systematic reviews have been reported recently, they were conflicting and with obvious deficiencies. Thus, we performed an objectively systematic review to determine whether BTXA is an effective and safe treatment for FS. A literature retrieval covering PubMed, Web of Science, Ovid, Embase and Cochrane library was performed on 16 January, 2015. Proportion meta-analysis and corresponding 95% confidence interval (CI) were performed to evaluate the efficacy and safety of BXTA in treatment of FS. A total of 499 records were retrieved and 22 articles with 23 studies were included after scrutiny by two independent authors. Statistical analyses regarding the effective rate, incidence of complications were used to estimate the efficacy and safety of BTXA. Our results suggested that the effective rate of BTXA for treatment of FS is 98.5% (95% CI = 0.971–0.994) and the incidence of complication is 3.6% (95% CI = 0.017–0.061). In conclusion, our study supports that BTXA produces meaningful benefits on the treatment of patients with FS. However, owing to lack of strong evidence, future studies with well-designed inclusion criteria and multicenter randomized controlled trials are needed to give more credible evidence, if possible.

Benign tumours affecting the deep lobe of the parotid gland: how to select the optimal surgical approach

Many types of approaches allow extra-capsular dissection in the deep parotid parenchyma in the treatment of benign tumours. A transcervical approach (TCA), transparotid approach (TPA) and a combined transcervical-transparotid approach (TPTCA) are the three main procedures performed to expose the deep parenchyma. We conducted a retrospective chart review enrolling 24 consecutive patients treated for benign tumours affecting the deep lobe of the parotid. Review of the surgical data was accompanied by careful follow-up to establish surgical morbidity, functional (Frey's Syndrome and first-bite syndrome) and aesthetical outcomes. A TPA was performed in the majority of cases; in 26% superficial parotidectomy was not required (selective deep parotidectomy). Minor's test showed a low rate of Frey's syndrome (3 cases of 23, 13%). No long-lasting first-bite syndrome was reported. Some additional procedures were easily performed in order to improve aesthetical results (rotational flap of sternocleidomastoid muscle, free abdominal fat transfer); these had the same results as selective deep parotidectomy. TCA (or TPTCA) ensures the best control of the facial nerve, providing good exposure and good functional and aesthetical results (without sparing the superficial parenchyma if additional techniques are performed with the aim of reducing skin depression in the treated area). The choice of the approach should have only the aim of safe resection and should not be influenced by aesthetical outcome; the craniocaudal level of the tumour seems to be the best indicator of the feasibility of the procedure also considering the branches of the facial nerve. In our experience, mandibulotomy can always be avoided.

[Quality of life after primary parotidectomy for benign tumor]

INTRODUCTION

Parotidectomy is commonly performed for various indications, including benign tumors of the parotid region. Esthetic or functional sequels of various importance and lasting effects may occur, as after any surgical procedure. These disorders may impact the patient's quality of life. The authors retrospectively evaluated the long-term outcome of patients having undergone conservative primary parotidectomy for a benign tumor, with a minimum follow-up of 10 years.

PATIENTS AND METHODS

A hundred and twenty-six superficial conservative primary or secondary parotidectomies were performed during 5 years, 94 (74.6%) of which for benign tumors. A flap of the sternocleidomastoid muscle (SCM) was inserted between the skin and facial nerve branches to prevent Frey's syndrome and alleviate surgical site depression according to some criteria. Questionnaires were completed at least 10 years after surgery.

RESULTS

The data of 53 patients was analyzed. 88.7% of patients had undergone a superficial parotidectomy and 11.3% a total one. The average histological tumor size was 3.3 cm (2.6 to 6.3 cm). The tumors were distributed as follows: pleomorphic adenoma in 79.4% of patients, cystadenolymphoma in 15.1%, oncocytoma in 3.7%, and basal cell adenoma in 1.8%. Twenty-six SCM flaps (49.1%) were performed. No patient presented with facial paresis or facial paralysis at the end of the study. The average follow-up was 10.4 years (10-11 years). Overall, social, psychological, and professional implications were reported by 7.5% of patients, and in 1.8% of cases the impact was significant. The use of a SCM flap seemed to prevent Frey's syndrome (Fischer test P=0.00001) and improved cosmetic results (Fisher test P<0.00001).

DISCUSSION

Conservative parotidectomy for primary benign tumors has a limited impact on the quality of life in the long run. This impact concerned 7.4% of patients. There was a significant impact in 2% of patients. We recommend filling the surgical site to improve functional and esthetic results and decrease long-term effects on the patient's quality of life.

Comparisons of Three Indicators for Frey's Syndrome: Subjective Symptoms, Minor's Starch Iodine Test, and Infrared Thermography

OBJECTIVES

To correlate Frey's syndrome with subjective symptoms, Minor's starch iodine test results, and infrared thermography measurements, and to discuss the utility of thermography as a quantitative diagnostic method.

METHODS

This study included 59 patients who underwent unilateral parotidectomy. A subjective clinical questionnaire and an objective Minor's starch iodine test were performed to evaluate the incidence of Frey's syndrome. Infrared thermography was performed, and the subjects were divided into seven groups according to the temperature differences between operated and unoperated sites. The thermal differences were correlated with the results from Minor's starch iodine test and the subjective symptoms questionnaire.

RESULTS

Of the 59 patients, 20 patients (33.9%) reported subjective symptoms after eating; 30 patients (50.8%) tested positive for Minor's starch iodine test, 19 patients (63.3%) of which reported subjective symptoms. Of the 29 patients who were negative for the iodine test, 2 patients (6.9%) reported subjective symptoms. Thus, subjective symptoms were well correlated with Minor's starch iodine test (r=0.589, P<0.001). As the thermal differences with infrared thermography increased, the number of patients with subjective symptoms increased (χ(2)=22.5, P<0.001). Using infrared thermography, the mean temperature difference in the positive group for the iodine test was 0.82℃±0.26℃, and that in the negative group was 0.10℃±0.47℃. With increased thermal differences, more patients showed positivity in the iodine test (χ(2)=29.9, P<0.001).

CONCLUSION

Subjective symptoms, Minor's starch iodine test, and infrared thermography are well correlated with one another. Quantitative thermography provides clues for the wide variation in the incidence of Frey's syndrome, and could be a useful method for diagnosing and studying Frey's syndrome.

Role of medical thermography in treatment of Frey's syndrome with botulinum toxin A

Frey syndrome classically causes gustatory sweating and facial flushing. We describe 2 cases in which medical thermography was used to investigate the symptoms. Images were taken after patients chewed a sialagogue and 2 weeks later they were given injections of botulinum toxin A. Images taken 4 weeks after treatment showed a considerable reduction in sweating and facial flushing, which was supported by the results of quality of life questionnaires completed before and after treatment. Medical thermography is much cleaner than the Minor's starch iodine test. It identifies areas of gustatory sweating, changes in temperature, and vascular changes, which potentially enable treatment to be targeted accurately.

Frey's syndrome: diagnosis in geriatric dentistry

Frey's syndrome, is characterized by warmth, flushing and sweating of the face, most of time in the preauricular region, initiated by any gustatory stimulus. It is frequently related to parotid surgery. A case of Frey's syndrome in a 81-year-old female whose long-delayed clinical onset post-parotidectomy is presented.

Frey's Syndrome Consequent to an Unusual Pattern of Temporomandibular Joint Dislocation: Case Report with Review of Its Incidence and Etiology

Frey's syndrome was first described in the 18(th) century. Recognizing it as a nonspecific condition, the symptom of gustatory sweating in patients with parotid gland inflammation was described by Duphenix and Baillarger. However, as a specific diagnostic entity, gustatory sweating, following trauma to parotid glands, was first described by Polish neurologist Lucie Frey, in 1923, and hence he proposed the term auriculotemporal syndrome. The condition is characterized by sweating, flushing, a sense of warmth, and occasional pain in the preauricular and temporal areas, following the production of a strong salivary stimulus. Several etiologies of Frey's syndrome have been mentioned in the literature; however, none attribute dislocation of the "intact" mandibular condyle as a cause of the syndrome. Reviewing its pathophysiology, etiology, and incidence in detail, we describe a case of Frey's syndrome subsequent to superolateral dislocation of the intact mandibular condyle following fracture of the anterior mandible. Its management and prevention are also discussed in brief.