The sternocleidomastoid muscle flap for the prevention of Frey syndrome and cosmetic deformity following parotidectomy: A systematic review and meta-analysis

Abstract

Approximately 34–86% of neoplasms of the salivary glands are located in the parotid gland and parotidectomy is the first-line treatment for parotid gland tumors. Frey syndrome and cosmetic deformity are common complications experienced by patients following parotidectomy and the sternocleidomastoid muscle flap (SCMF) is used to prevent them. Numerous studies have been performed to examine the effectiveness of the SCMF for the prevention of cosmetic deformity and Frey syndrome, however, they provide contradictory results and possess small sample sizes with consequently low statistical power. In order to evaluate the effectiveness of the SCMF for the prevention of Frey syndrome and cosmetic deformity following parotidectomy, we performed a systematic review and meta-analysis based on published randomized controlled trials (RCTs), which were identified using PubMed and CNKI databases, and references of studies up to August 2012 were included. Using these criteria, we yielded 11 RCTs. Following an independent assessment of the methodological quality of these studies and the extraction of data, a systematic review and meta-analysis was conducted. The results of the meta-analysis demonstrated that there was a significant trend towards a lower risk of objective incidence [67%; risk ratio (RR), 0.33; 95% confidence interval (CI), 0.16–0.67; P<0.01] and subjective incidence (66%; RR, 0.34; 95% CI, 0.16–0.75; P= 0.01) of Frey syndrome in the SCMF group. The sensitivity analysis also indicated that this result was significant. Due to the considerable variation between the included studies, a meta-analysis was not applicable to assess cosmetic deformity. Two RCTs demonstrated that the difference between the SCMF and no SCMF group was not statistically significant, while the other seven RCTs detected a statistically significant difference between the two groups. Publication bias was detected. In conclusion, based on currently available evidence, the use of the SCMF is benefical for the prevention of Frey syndrome, however, whether it is also benefical for cosmetic deformity remains inconclusive.

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

“…The different barriers include local muscle flaps such as the sternocleidomastoid or temporal muscle, free nonvascularized fascia or fat grafts, animal or cadaveric fascia‐like tissue, and synthetic materials. The evidence for sternocleidomastoid flaps is inconclusive at the present time, whereas meta‐analysis seems to conclude for a protective effect of acellular dermis matrix grafts in the prevention of Frey syndrome after parotidectomy. However, these grafts seem to be associated with a higher incidence of local wound complications such as sialoceles and salivary fistula …”

“…The existence of previous meta‐analysis on the subject was searched for on PubMed and Embase databases with the terms “Frey syndrome” and “meta‐analysis” and “prevention.” Of the seven articles found, one did not deal with parotidectomy, two evaluated sequels http://www.oxforddictionaries.com/definition/english/sequel of parotidectomy in general, and four articles evaluated the potential benefits for Frey syndrome prevention by the use of a sternocleidomastoid muscle rotation flap or different graft materials . Thus, no previous meta‐analysis addressed the use of a SMAS flap for Frey syndrome prevention.…”

Reconstruction of limited parotidectomy defects using the dermofat graft

“…This is due to the interface between removed and intact superficial parotid tissue creating a step deformity. Reconstructive options include fat grafting, the sternocleidomastoid muscle (SCM) flap, the superficial musculoaponeurotic system (SMAS) flap, acellular dermal matrix, through to free flap reconstruction for complex defects. Each reconstructive approach has its own advantages and drawbacks with regard to defect size, donor site morbidity, complexity and complication rate .…”

“…Reconstructive options include fat grafting, the sternocleidomastoid muscle (SCM) flap, the superficial musculoaponeurotic system (SMAS) flap, acellular dermal matrix, through to free flap reconstruction for complex defects. Each reconstructive approach has its own advantages and drawbacks with regard to defect size, donor site morbidity, complexity and complication rate . In many cases, the aim of the reconstruction extends beyond contour restoration to also reduce the incidence and severity of other complications such as Frey's syndrome by hindering the aberrant innervation of dermal sweat glands by salivary parasympathetic nerve fibres …”

“…Each reconstructive approach has its own advantages and drawbacks with regard to defect size, donor site morbidity, complexity and complication rate . In many cases, the aim of the reconstruction extends beyond contour restoration to also reduce the incidence and severity of other complications such as Frey's syndrome by hindering the aberrant innervation of dermal sweat glands by salivary parasympathetic nerve fibres …”