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

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.

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.