The superficial musculoaponeurotic system flap in the prevention of Frey syndrome: A meta-analysis

SMAS flap for extracapsular dissection of parotid gland tumors: is it necessary?

OBJECTIVE

The aim of this retrospective article is to evaluate postoperative outcomes after extracapsular dissection for small benign superficial parotid neoplasms (<3 cm) in patients who received Superficial Musculoaponeurotic System (SMAS) flap and in patients who did not receive it.

METHODS

Two groups were created and statistically compared regarding Frey's syndrome and aesthetic satisfaction by data collected through the POI-8 validated questionnaire and through an aesthetic satisfaction scale ranging from 1 to 10. The difference between these two groups was the utilization of SMAS flap. SMAS flap was harvested in one of these two group, meanwhile was not used in the other.

RESULTS

The p-value analysis between group 1 and group 2 on these complications, resulted statistically not significant. Also, the aesthetic satisfaction resulted not statistically significant between group 1 and group 2. Gender, localization, and facial palsy resulted statistically correlated with the aesthetic satisfaction (p-value < 0.05).

CONCLUSION

In conclusion, there is no statistical difference in the use of SMAS flap for benign parotid neoformations of the superficial lobe, with a diameter of less than 3 cm for which extracapsular dissection is adopted as a surgical technique.

LEVEL OF EVIDENCE: 3

Evaluation of functional and aesthetic outcomes of free dermal fat graft versus superficial musculoaponeurotic system flap after superficial parotidectomy: randomized clinical trial

BACKGROUND

Parotidectomy is the standard procedure for treatment of many parotid lesions; however, it has several drawbacks. Facial asymmetry and Frey's syndrome are the most annoying complications to patients. Insertion of interpositioning grafts into the parotidectomy bed can decrease these complications significantly. Free dermal fat graft (FDFG) and superficial musculoaponeurotic system (SMAS) flap have very promising results. This RCT aimed to compare these two techniques regarding functional and aesthetic outcomes.

METHODS

Between February 2016 and October 2021, adult patients undergoing superficial conservative parotidectomy in a single centre for a benign indication were randomized into two equal groups using a closed envelope method. In one group, FDFG was inserted at the parotidectomy bed, whereas, in the other group, SMAS flap was performed. Preoperative, operative, and postoperative data were recorded and analysed. The primary outcome was the development of Frey's syndrome.

RESULTS

Seventy-eight patients were randomized into two equal groups of 39 patients. There was no significant difference between the two groups regarding development of Frey's syndrome. There was no significant statistical difference between study groups regarding demographic data, co-morbidities, parotid pathologies, specimen volumes, total operating time, and postoperative complications. A tendency for over correction was observed in FDFG and under correction in SMAS flap. There was no statistically significant difference between the study groups regarding the patients' aesthetic satisfaction with the majority displaying excellent satisfaction with no poor results.

CONCLUSION

FDFG and SMAS flap are simple, rapid, and reliable procedures and are effective in improving both functional and aesthetic outcomes post-parotidectomy. They have comparable results; however, selection of either procedure can be determined according to patient and tumour characteristics. Registration number: NCT05452837 (http://www.clinicaltrials.gov).

Facial Reanimation and Reconstruction of the Radical Parotidectomy

Radical parotidectomy may result from treating advanced parotid malignancies invading the facial nerve. Survival is often enhanced with multimodality treatment protocols, including postoperative radiation therapy. In addition to the reconstructive challenge of restoring facial nerve function, patients may be left with a significant cervicofacial concavity and inadequate skin coverage. This should be addressed with stable vascularized tissue that is resistant to radiation-induced atrophy. This article describes a comprehensive strategy, includes the use of the anterolateral thigh free flap, the temporalis regional muscle transfer, motor nerve to vastus lateralis grafts, nerve to masseter transfer, and fascia lata grafts for static suspension.

Meta-Analysis to Evaluate the Efficacy of Sternocleidomastoid Muscle Flap as a Reconstruction Modality in Prevention of Frey's Syndrome Following Parotidectomy

BACKGROUND

One of the commonest complications following parotidectomy is Frey's syndrome (FS). The use of sternocleidomastoid muscle (SCM) flap to prevent FS is controversial. Hence, this study has been designed to compare the effect of SCM flap with no reconstruction in prevention of FS following parotidectomy.

METHODOLOGY

An exhaustive literature search was conducted in July 2019. Studies focusing on sternocleidomastoid flap following parotidectomy were included in the meta-analysis. A random effects model was used to generate pooled estimates. Odds ratio with a 95% confidence interval was calculated for subjective symptoms and objective test.

RESULTS

A total of 125 studies were identified, out of which 17 studies were recruited in the meta-analysis. Sixteen studies were analyzed for the subjective symptoms, and ten were analyzed for the objective signs. There was no statistically significant difference in the occurrence of FS with the use of SCM flap on objective analysis. However, the subjective analysis showed a statistically significant reduction in FS following reconstruction with SCM flap after parotidectomy.

CONCLUSION

The present meta-analysis suggests that the use of SCM flap following parotidectomy has no effect in reducing the incidence of Frey's syndrome.

The Pretragal Superficial Musculoaponeurotic System Fascia: A New Graft Material for Transcanal Tympanoplasty

OBJECTIVE

To compare outcomes of transcanal endoscopic tympanoplasty reconstructed using pretragal superficial musculoaponeurotic system (SMAS) fascia versus temporalis fascia.

STUDY DESIGN

Retrospective patient review and posttreatment questionnaire survey.

SETTING

Tertiary referral center.

PATIENTS

Sixty adult patients with chronic dry tympanic membrane perforation.

INTERVENTIONS

Patients underwent transcanal endoscopic type I tympanoplasty reconstructed using the SMAS fascia between September 2017 and May 2018; outcomes were compared with a matched cohort of patients where the temporalis fascia was used.

MAIN OUTCOME MEASURES

Tympanic membrane closure rate, audiogram threshold, duration of procedure, and donor site scar satisfaction survey.

RESULTS

Sixty patients were included in this study and were evenly divided into the SMAS and temporalis fascia groups. These cohorts were matched for age, sex, side of lesion, perforation size, and preoperative hearing level. The closure rate was 96.7% (29/30) and 93.3% (28/30) (p = 1.0), mean hearing gain was 8.3 ± 6.4 dB versus 8.2 ± 7.1 dB for air-conduction (p = 0.970) and 7.6 ± 5.1 dB versus 8.2 ± 6.8 dB for air-bone gap (p = 0.716), and mean surgical duration was 137.3 ± 23.0 versus 132.2 ± 27.3 minutes (p = 0.432) for the SMAS and temporalis fascia groups, respectively; there were no statistically significant differences for all the parameters listed. The posttreatment questionnaire survey revealed significantly higher acceptance of the SMAS fascia method.

CONCLUSION

This preliminary outcome report of SMAS fascia grafting in transcanal endoscopic type I tympanoplasty showed equivalent surgical outcomes and better cosmetic satisfaction compared with the temporalis fascia. The SMAS fascia is a reasonable alternative to conventional techniques for transcanal tympanoplasty.

Autologous Free Dermal-Fat-Fascial Graft for Parotidectomy Defects: A Case Series

Background:

Frey’s syndrome and facial asymmetry from loss of parotid tissue are long-term sequelae of parotid surgeries causing significant morbidity. Various techniques have been used to fill the parotidectomy defect, preserve facial contour symmetry, and prevent Frey’s syndrome. Free dermal-fat-fascial graft (DFFG) is one such technique; however, its use is largely undocumented in the literature. In this case series, we investigate the efficacy of free DFFG in reconstructing parotidectomy defects at 2 tertiary care centers.

Materials and methods:

Medical records of 54 patients who underwent primary parotidectomy and immediate reconstruction with autologous abdominal free DFFG by 2 surgeons in George Washington University Hospital and McGill University Health Centre between 2007 and 2019 were collected prospectively. Patients responded to 2 questionnaires addressing postoperative outcomes.

Results:

Fifty-four patients were included; 32 superficial parotidectomies and 22 total parotidectomies were performed for 39 benign and 15 malignant tumors. Thirty-seven patients could be reached. Out of 37 patients who responded to the first questionnaire, 59% (22) reported complete facial symmetry, 27% (10) reported mild hollowness, and 14% (5) reported mild fullness. None declared noticeable hollowness or fullness. While 81% (30) did not experience Frey’s syndrome, 5.4% (2) experienced mild symptoms without disability, and 13.5% (5) experienced debilitating symptoms. Out of 37 patients, 8 patients responded to a second questionnaire addressing the outcome of the abdominal graft donor site. In regard to the donor site, 87.5% (7) were satisfied or very satisfied from its cosmetic appearance, 75% (6) were not bothered by its cosmetic appearance, and 87.5% (7) had no discomfort at the graft donor site. Patients did not report any other symptom at the graft donor site.

Conclusion:

In this large series of total parotidectomies including malignant pathologies, autologous abdominal free DFFG effectively prevented Frey’s syndrome and preserved facial cosmesis in most patients.

Different Surgical Strategies in the Prevention of Frey Syndrome: A Systematic Review and Meta-analysis

OBJECTIVE/HYPOTHESIS

To define the best surgical technique able to reduce Frey syndrome (FS) incidence after parotidectomy.

STUDY DESIGN

Systematic review and network meta-analysis.

METHODS

An arm-based network analysis was conducted using a Bayesian hierarchical model. The primary and secondary outcomes were the incidence of subjective (clinical) and objective (positive starch-iodine test result) FS, respectively.

RESULTS

A total of 3830 patients with a median age of 50.35 years (n = 2323; IQR 44.25-54.18) were included for six interventions [temporoparietal fascia (TPFF), free fat graft (FFG), acellular dermal matrix (ADM), sternocleidomastoid muscle (SCM) flap, and superficial musculoaponeurotic system (SMAS) flap]. If compared to no treatment, the greatest reduction of subjective (clinical) FS incidence was measured for the TPFF (OR: 0.07, CI: 0.004-0.57), the ADM (OR: 0.09, CI: 0.02-0.35), and the FFG (OR: 0.11, CI: 0.03-0.42) techniques. However, a significant difference was measured also for the SCM flap (OR: 0.38, CI: 0.18-0.73) and for the SMAS flap (OR: 0.42, CI: 0.19-0.97). All treatments showed a significant reduction of the objective FS incidence if compared to no treatment (FFG, OR: 0.06, CI: 0.002-0.62; TPFF, OR: 0.07, CI: 0.01-0.33; ADM, OR: 0.11, CI: 0.03-0.44; SMAS, OR: 0.36, CI: 0.17-0.71; SCM, OR: 0.40, CI: 0.19-0.74).

CONCLUSIONS

TPFF, ADM, and FFG seem to be the best treatment strategies to prevent FS after parotidectomy. Further randomized controlled trials comparing these techniques should be conducted to define specific indications. Laryngoscope, 131:1761-1768, 2021.

What is the best method for prevention of postparotidectomy Frey syndrome? Network meta-analysis

BACKGROUND

Prevention of Frey syndrome (FS) after parotidectomy using an interposition barrier has long been gaining a wide popularity; however, there is no clear evidence regarding which preventive technique is more effective. The aim of this network meta-analysis (NMA) is to answer the question: What is the best method for prevention of FS after parotidectomy?

METHODS

A comprehensive search of the PubMed, Embase, SCOPUS, and Cochrane library was conducted to identify the eligible studies. The outcome was the incidence of subjective Frey syndrome (SFS) and objective Frey syndrome (OFS). The Bayesian NMA accompanied with a random effects model and 95% credible intervals (CrIs) were calculated using GeMTC R package.

RESULTS

Thirty-four studies (n = 2987 patients) with five interventions, namely Alloderm (ADM), temporoparietal fascia (TPF), sternocleidomastoid muscle (SCM), superficial musculoaponeurotic system (SMAS), and free fat graft (FFG), were compared together and with no interposition barrier (NB). The results of NMA showed a statistically significant reduction in both SFS and OFS when ADM, TPF, SMAS, FFG, and SCM were compared with NB. No statistical differences were observed when comparing ADM, SCM, SMAS, FFG, and TPF. TPF ranked the best of all treatments (59.4%) and was associated with the least incidence of SFS; whereas ADM ranked the best of all treatments (61.1%) and was associated with the least incidence of OFS.

CONCLUSIONS

All interventions (TPF flap, ADM, FFG, SMAS, and SCM) were associated with a significant reduction in the incidence of FS when compared with NB. TPF and ADM showed the best outcome with the least incidence of SFS and OFS, respectively.

Prospective outcomes following drainless superficial parotidectomy with sternocleidomastoid flap reconstruction

Background

Patients undergoing superficial parotidectomy for benign parotid lesions are at risk of postoperative complications, most notably cosmetic complications such as facial paralysis and contour defects, and functional complications including Frey’s syndrome. Traditionally, surgical drains have been placed at the end of surgery to prevent hematoma and sialocele formation. However, this can increase the risk of postoperative complications and contribute to a prolonged course in hospital. To try and prevent these risks and complications, we introduced a novel technique of a drainless parotidectomy by reconstructing the resulting parotid bed defect with a superiorly based sternocleidomastoid (SCM) rotational flap and by placement of gelfoam into the wound bed and a facelift dressing postoperatively to provide additional hemostasis and avoid drain placement.

Methods

All patients with benign parotid disease undergoing a drainless superficial parotidectomy and reconstruction with a superiorly based SCM rotational flap at our center were identified within a prospective cohort database between July 2010–2018. Primary outcomes included postoperative cosmetic and functional outcomes, complications and length of hospital stay. A secondary cost analysis was done to compare this novel technique to traditional superficial parotidectomy with surgical drain placement.

Results

Fifty patients were identified within the database and were included in the final analysis. The average length of hospital stay was 1.02 days. All patients were satisfied with their aesthetic outcome at 1 year. During long term follow-up, 63% of patients reported normal appearance of the operated side. Seven patient’s (14%) developed temporary facial paresis following surgery. All patients had resultant normal facial function at follow-up in 1 year. No patients developed subjective Frey’s Syndrome. Two patients (4%) developed a postoperative sialocele requiring drainage and one patient (2%) developed a hematoma on extubation requiring evacuation and drain placement. Cost analysis demonstrated a cost savings of approximately $975 per person following surgery.

Conclusion

In the current study, we introduced a novel approach of a drainless superficial parotidectomy using a superiorly based SCM flap, gelfoam and placement of a post-operative facelift dressing. This drainless approach was associated with good long-term cosmetic and functional outcomes with few postoperative complications. This new technique may also offer the potential for long-term savings to the health care system.

Reconstruction using sternocleidomastoid muscle flap versus posterior belly of digastric muscle flap compared with no reconstruction following superficial parotidectomy

INTRODUCTION

The most common complications following superficial parotidectomy are formation of contour deformity and development of Frey's syndrome. Multiple modalities are being used to prevent these complications. We hereby intend to compare the reconstruction modalities (sternocleidomastoid (SCM) muscle flap, posterior belly of digastric (PBD) muscle flap) with) No reconstruction (NR) following superficial parotidectomy.

MATERIALS AND METHODS

A comparative study was designed which included 15 patients requiring parotidectomy. These patients were divided into three groups viz. SCM, PBD, and NR. The functional outcome (facial nerve involvement, Frey syndrome, ear lobule sensation, neck movements) and the esthetic results were evaluated subjectively and objectively. The outcomes were statistically evaluated using chi-square test and ANOVA test.

RESULTS

Facial nerve palsy occurred in 2 cases in each group, and all of them recovered completely within 6 months. The Minor starch iodine test was positive in 1 patient in the SCM group, in 2 patients in the PBD group, and in 4 patients in the NR group; only 1 patient of PBD group and 3 patients of NR group complained of gustatory sweating. Neck movements were unaffected in the PBD and NR groups; however, 1 patient complained of mild discomfort and pain during neck movements in the SCM group.

CONCLUSION

Primary closure showed the worst results regarding cosmetic deformity. Hence, it is recommended to mandatorily reconstruct the defect. However, the sternocleidomastoid muscle flap is a better cosmetic option compared with posterior belly of digastric muscle flap. In cases with larger defects, a combination of both the flaps can be used. SCM flap also lowers the incidence of Frey syndrome objectively and subjectively with no reported hazard of the spinal accessory nerve and mildly affected neck movements.

Minor Parotidectomy Complications: A Systematic Review

OBJECTIVES

To report descriptive statistics for minor parotidectomy complications.

METHODS

A systematic review was performed, selecting 235 studies for analysis. The incidence of complications was tabulated, and descriptive statistics calculated. Outlier studies, 1 standard deviation above the mean, were reexamined to determine potential causal factors for each complication. All studies were examined for statistically significant differences for any potential causal factor.

RESULTS

The pooled incidence of minor complications reported were hematoma 2.9% (95% confidence interval [CI]: 2.4-3.5), wound infection 2.3% (95% CI: 1.8-2.9), sialocele 4.5% (95% CI: 3.5-5.7), salivary fistula 3.1% (95% CI: 2.6-3.7), flap necrosis 1.7% (95% CI: 1.1-2.5), scar issues 3.6% (95% CI: 2.4-5.4), numbness 33.9% (95% CI: 25.6-43.4), and deformity 11.8 (95% CI: 6.9-19.5). Implants result in more wound complications, such as hematoma, sialocele, or salivary fistula. Sialocele and salivary fistula appear more frequently after less extensive parotid surgery, whereas hematoma, wound infections, flap necrosis, and aesthetic considerations are worse with more extensive resections.

CONCLUSIONS

Minor parotidectomy complications are more frequent than generally assumed and related to certain factors that should be investigated. Laryngoscope, 131:571-579, 2021.

Dermal Fat Grafting to Reconstruct the Parotidectomy Defect Normalizes Facial Attention

OBJECTIVES/HYPOTHESIS

Use validated eye-tracking technology to objectively measure 1) the attentional distraction of facial contour defects after superficial and total parotidectomy and 2) changes in attentional distraction with abdominal dermal fat graft reconstruction.

METHODS

Standardized frontal and oblique facial images of 16 patients who had undergone superficial or total parotidectomy with or without fat graft reconstruction; four normal controls were obtained. One hundred casual observers were recruited to view these images, and gaze data were collected using a Tobii Pro eye-tracking system. Gaze durations for predefined facial areas of interest were analyzed using mixed-effects linear regression to test study hypotheses.

RESULTS

For frontal images, total parotidectomy increased gaze to the operated parotid area compared to the contralateral nonoperated parotid area (92 milliseconds, 95% confidence interval [CI]: 48-138 milliseconds, P < .001). Fat grafting normalized the attentional distraction, with no difference in gaze time on the operated parotid region compared to normal control faces (P = .414). For oblique images, total parotidectomy increased gaze to the operated parotid area compared to the contralateral nonoperated parotid area (658 milliseconds, 95% CI: 463-854 milliseconds, P < .001). Fat grafting normalized this attentional distraction, with no difference in gaze time on the operated parotid region compared to normal control faces (P = .504). In both views, superficial parotidectomy demonstrated no significant attentional distractions, with or without fat grafting.

CONCLUSIONS

This eye-tracking study objectively demonstrates that total parotidectomy results in a facial contour deformity that is distracting to observers, whereas superficial parotidectomy does not. For total parotidectomy, this attentional distraction can be normalized with dermal fat graft reconstruction.

LEVEL OF EVIDENCE

3b Laryngoscope, 131:E124-E131, 2021.

Methodological Quality of Systematic Reviews and Meta-analyses Published in High-Impact Otolaryngology Journals

OBJECTIVE

To assess the methodological quality of intervention-focused systematic reviews (SRs) and meta-analyses (MAs) published in high-impact otolaryngology journals.

DATA SOURCES

Ovid Medline, Embase, and Cochrane Library.

REVIEW METHODS

A comprehensive search was performed for SR and MA citations from 2012 to 2017 in the 10 highest impact factor otolaryngology journals. Abstracts were screened to identify published manuscripts in which the authors indicated clearly that they were performing an SR or MA. Applying a modified typology of reviews, 4 reviewers characterized the review type as SR, MA, or another review type. A simplified version of the AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews 2) tool was used to assess the reporting and methodological quality of the SRs and MAs that were focused on interventions.

RESULTS

Search and abstract screening generated 499 manuscripts that identified themselves as performing an SR or MA. A substantial number (85/499, 17%) were review types other than SRs or MAs, including 34 (7%) that were literature reviews. In total, 236 SRs and MAs focused on interventions. Over 50% of these SRs and MAs had weaknesses in at least 3 of the 16 items in the AMSTAR 2, and over 40% had weaknesses in at least 2 of the 7 critical domains. Ninety-nine percent of SRs and MAs provided critically low confidence in the results of the reviews.

CONCLUSION

Intervention-focused SRs and MAs published in high-impact otolaryngology journals have important methodological limitations that diminish confidence in the results of these reviews.

Modified facelift incision and superficial musculoaponeurotic system flap in parotid malignancy: a retrospective study and review of the literature

Background

Data reporting the use of modified facelift incision (MFI) approach with or without superficial musculoaponeurotic system (SMAS) reconstruction in parotid malignancy are limited. To enhance the limited knowledge in this subject, the authors of the current study report quality data of MFI in patients with parotid malignancy with or without SMAS reconstruction.

Methods

We performed a retrospective review of parotid malignancy patients treated with the MFI over a 5-year period (2015–2019) in the 1st ENT University Department, University of Athens, Greece.

Results

We identified five patients with parotid malignancy. We performed MFI parotidectomy in 5/5 patients and SMAS reconstruction in 2/5 patients. All tumors were classified as T1N0M0. After a mean follow-up of 43.6 months (minimum, 36; maximum, 55), we noted no recurrence. The patients reported no Frey’s syndrome.

Conclusions

The authors of the current study suggest consideration of the MFI approach in parotid malignancy. A MFI approach should at least favor small parotid tumors without neck metastatic disease (T1cN0). Surgeons could also address larger tumors with a MFI approach. Surgeons should reconstruct the parotid lodge with a SMAS advancement flap in tumors not in proximity with the SMAS.

Reconstructive trends and complications following parotidectomy: incidence and predictors in 11,057 cases

BACKGROUND

Parotidectomy is a common treatment option for parotid neoplasms and the complications associated with this procedure can cause significant morbidity. Reconstruction following parotidectomy is utilized to address contour deformity and facial nerve paralysis. This study aims to demonstrate national trends in parotidectomy patients and identify factors associated with adverse postoperative outcomes. This study includes the largest patient database to date in determining epidemiologic trends, reconstructive trends, and prevalence of adverse events following parotidectomy.

METHODS

A retrospective review was performed for parotidectomies included in the ACS-NSQIP database between January 2012 and December 2017. CPT codes were used to identify the primary and secondary procedures performed. Univariate and multivariate analysis was utilized to determine associations between pre- and perioperative variables with patient outcomes. Preoperative demographics, surgical indications, and common medical comorbidities were collected. CPT codes were used to identify patients who underwent parotidectomy with or without reconstruction. These pre- and perioperative characteristics were compared with 30-day surgical complications, medical complications, reoperation, and readmission using uni- and multivariate analyses to determine predictors of adverse events.

RESULTS

There were 11,057 patients who underwent parotidectomy. Postoperative complications within 30 days were uncommon (1.7% medical, 3.8% surgical), with the majority of these being surgical site infection (2.7%). Free flap reconstruction, COPD, bleeding disorders, smoking, and presence of malignant tumor were the strongest independent predictors of surgical site infection. Readmission and reoperation were uncommon at an incidence of 2.1% each. The strongest factors predictive of readmission were malignant tumor and corticosteroid usage. The strongest factors predictive of reoperation were free flap reconstruction, malignant tumor, bleeding disorder, and disseminated cancer. Surgical volume/contour reconstruction was relatively uncommon (18%). Facial nerve sacrifice was uncommon (3.7%) and, of these cases, only 25.5% underwent facial nerve reinnervation and 24.0% underwent facial reanimation.

CONCLUSIONS

There are overall low rates of complications, readmissions, and reoperations following parotidectomy. However, certain factors are predictive of adverse postoperative events and this data may serve to guide management and counseling of patients undergoing parotidectomy. Concurrent reconstructive procedures are not commonly reported which may be due to underutilization or underreporting.

Graft interposition for preventing Frey's syndrome in patients undergoing parotidectomy

BACKGROUND

Frey's syndrome is characterised by transient flushing and sometimes facial sweating in the area of the auriculotemporal nerve. It most commonly occurs after parotidectomy, but other causes may include submandibular gland surgery, mandibular condylar fracture, obstetric (forceps) trauma, sympathectomy and metabolic disease. Although the pathophysiology of Frey's syndrome remains controversial, the generally accepted hypothesis is that it occurs as the result of injury to the auriculotemporal nerve.There is currently no clear evidence to establish the efficacy and safety of the different methods used for the treatment of Frey's syndrome, therefore the prevention of this symptom during surgery is important. The main method used for prevention is the interposition of a graft between the skin flap and the parotid bed during surgery. Biomaterials, allograft or autograft can be used for this purpose.

OBJECTIVES

To evaluate the effects and safety of biomaterial, allograft or autograft interposition for the prevention of Frey's syndrome in patients undergoing parotidectomy, and to identify its effect on prevention and delayed occurrence.

SEARCH METHODS

The Cochrane ENT Information Specialist searched the Cochrane ENT Trials Register; Cochrane Register of Controlled Trials (CENTRAL; 2019, Issue 2); Ovid MEDLINE; Ovid Embase; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 5 February 2019.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in patients with parotid disease (including tumours, inflammation, trauma etc.) undergoing parotidectomy with a minimal follow-up period of six months. We planned to include trials with interventions including biomaterial, allograft or autograft interposition alone or in combination with other surgical techniques. We included trials that compared any graft interposition and no graft interposition, or different graft interpositions.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. Our primary outcome measures were incidence rate of Frey's syndrome assessed clinically (Minor's starch-iodine test) and other complications (postoperative infection, subjective painful or restricted cervical movement, scar spread, rejection of the graft, complications related to the donor site such as accessory nerve injury and haematoma). Our secondary outcome measures were incidence rate of Frey's syndrome assessed by participants (by questionnaire) and sweating area assessed by Minor's starch-iodine test. We used GRADE to assess the certainty of the evidence for each outcome.

MAIN RESULTS

We included three RCTs (124 participants), two of which we assessed as at high risk of bias and one at unclear risk of bias. All studies were hospital-based and recruited participants undergoing superficial parotidectomy. Most participants were diagnosed with benign lesions of the parotid gland. Participants were followed up for more than six months. The studies evaluated the two comparisons shown below:Sternocleidomastoid muscle flap versus no flapTwo studies assessed this comparison. Both assessed the effects of the sternocleidomastoid muscle flap procedure on the incidence rate of Frey's syndrome assessed clinically but neither showed a significant difference between groups (risk ratio (RR) 0.08, 95% confidence interval (CI) 0.00 to 1.23; 24 participants and RR 1.23, 95% CI 0.88 to 1.73; 36 participants; very low-certainty evidence). We did not pool the data due to the high heterogeneity (I² = 87%).One study found that the sternocleidomastoid muscle flap may result in little or no difference in other complications including haematoma (RR 2.18, 95% CI 0.09 to 50.16; 36 participants; low-certainty evidence), subjective painful or restricted cervical movement (RR 0.54, 95% CI 0.14 to 2.05; 36 participants; low-certainty evidence) and scar spread in the cervical region (RR 0.71, 95% CI 0.05 to 10.54; 36 participants; low-certainty evidence). Both studies reported the incidence rate of Frey's syndrome assessed by participants, with one reporting no events in either group and the other finding no evidence of a difference (RR 0.63, 95% CI 0.32 to 1.26; 36 participants; low-certainty evidence).Acellular dermal matrix versus no graftOnly one study assessed this comparison. Use of an acellular dermal matrix graft may result in little or no difference to the incidence rate of Frey's syndrome (assessed clinically) in comparison with the no graft group, but the evidence is very uncertain (RR 0.08, 95% CI 0.00 to 1.25; 30 participants; very low-certainty evidence).Acellular dermal matrix may slightly increase the wound infection rate compared with control (RR 17.00, 95% CI 1.02 to 282.67; 64 participants; low-certainty evidence). Acellular dermal matrix may result in little or no difference to the incidence of seromas or sialoceles (RR 2.33, 95% CI 0.66 to 8.23; 64 participants; low-certainty evidence). Acellular dermal matrix may result in little or no difference to the incidence rate of Frey's syndrome (assessed by participants) in comparison with the no graft group (RR 0.33, 95% CI 0.04 to 3.04; 64 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

The evidence for the effectiveness of graft interposition in preventing Frey's syndrome is of low or very low certainty. The use of acellular dermal matrix may be associated with an increase in the wound infection rate, and little or no difference in the incidence of seromas or sialoceles. Further studies are needed to draw reliable conclusions.

Temporoparietal frey syndrome: An uncommon variant of a common syndrome

OBJECTIVES/HYPOTHESIS

To describe a previously unreported variant of Frey syndrome. Gustatory sweating is a common complication of parotidectomy and typically directly overlies the surgical site or parotid bed. In some instances, the sweating may occur beyond the parotid bed or involve tissue that was undisturbed during the procedure.

STUDY DESIGN

Retrospective case series.

METHODS

All cases of temporoparietal Frey syndrome in a single surgeon's experience were reviewed.

RESULTS

Seven patients were found to have temporoparietal Frey syndrome. Three patients had concomitant first bite syndrome. Three patients had some form of reconstruction at time of surgery. The mean time to onset of symptoms was 11.5 months, with a range of 7 to 21 months. Four patients did not require any treatment for their symptoms, but two patients required intradermal Botox injections for symptomatic relief.

DISCUSSION

This study describes a previously unreported variant of Frey syndrome with symptoms occurring distal to the parotid gland. This likely develops either by regeneration of severed postganglionic fibers into sympathetic targets distally along the course of the auriculotemporal nerve or by regeneration into fibers of the sympathetic plexus traveling along the superficial temporal artery.

LEVEL OF EVIDENCE

Laryngoscope, 129:2071-2075, 2019.

Antegrade versus retrograde facial nerve dissection in benign parotid surgery: Is there a difference in postoperative outcomes? A meta-analysis

OBJECTIVE

The primary aim of this meta-analysis was to test the null hypothesis of no difference in facial nerve dysfunction in studies that compared classical antegrade facial nerve dissection (AFND) versus retrograde facial nerve dissection (RFND) during benign parotid surgery.

METHODS

A comprehensive search of PubMed, the Cochrane Central Register of Controlled Trials, Scopus, Google Scholar, Science Direct and relevant journals was undertaken up to June 27, 2018. Randomized controlled clinical trials (RCTs), controlled clinical trials (CCTs), and retrospective studies aimed at comparing the effect of AFND vs. RFND during parotidectomy were included. The outcome measures included facial nerve dysfunction, Frey's syndrome, recurrence, silaocele, salivary fistula, operating time length of hospital stay, and estimated blood loss. Pooled risk ratio (RR) and weighted mean differences (MD) with 95% confidence intervals were calculated using either a fixed-effects or random-effects model.

RESULTS

Ten studies; four RCTs and five retrospective studies were included. There were 570 patients (319 in RFND group and 251 in AFND group). 481 patients in 9 studies reported the incidence rate of facial nerve dysfunction. No statistical significant difference was observed between both groups concerning the occurrence of transient or permanent facial nerve paralysis (p = 0.44 and 0.11 respectively). One out 10 studies reported the incidence rate of sialocele, however no statistical difference was observed between the two techniques. There was reduction in the operative time (19.30 min), amount of blood loss (25.08 ml) and amount of healthy salivary tissues removed (12.20 mm) in RFND compared with AFND.

CONCLUSIONS

According to the results of the current review there is no evidence demonstrating a significant advantage of one approach over another, therefore, well-designed standardized RCTs are required.

The Effects of Superficial Musculoaponeurotic System Flap on the Development of Frey's Syndrome and Cosmetic Outcomes After Superficial Parotidectomy

Objective

To investigate the outcomes of superficial musculoaponeurotic system (SMAS) flap and classic techniques in superficial parotidectomy in terms of Frey's syndrome (FS) and cosmetic satisfaction.

Methods

In this study, a retrospective chart review of patients that underwent superficial parotidectomy was performed. These patients were divided into two subgroups: group 1 included patients in which the SMAS flap was harvested and group 2 comprised the remaining patients on whom classic superficial parotidectomy was performed. All the patients were evaluated clinically and with Minor's starch-iodine test for FS. For the evaluation of the cosmetic results, the patient's satisfaction was queried according to the incision scar and surgical field skin retraction/facial symmetry. Both groups were compared in terms of complications and numbness of surgical area.

Results

Fifty-five patients (31 male and 24 female) with a mean age of 50.19 years were included in the study. Thirty-two patients were in group 1 and 23 in group 2. Thirteen patients (23.7%) described as having FS and six of them were in group 1, while seven were in group 2. Minor's starch-iodine test was positive in nine patients in group 1 (28.1%) and six patients in group 2 (26.1%) (p=1.000). With regard to cosmetic satisfaction, eight patients (25%) stated mild discomfort from the incision scar and two patients (6.3%) stated cosmetic dissatisfaction for facial asymmetry in group 1. In group 2 for the same factors the number of patients were 11 (47.8%) and 2 two (8.7%), respectively (p=0.027). There were no statistically significant differences in means of complication and numbness (p>0.05).

Conclusion

According to our study results, there was no superiority between both the groups in terms of FS and incision scar satisfaction. We determined that there was a significant benefit of SMAS flap application in the prevention of volume loss and surgical area retraction.