Platysmal Lineaments of the Neck with Emphasis on Endoscopic Endocrine Surgery

Background: In endoscopic neck endocrine surgery, the subplatysmal plane is an anatomic key structure that must be identified and preserved, to progress with the dissection. We define the prevalence of platysma, in the intermediate plane of the anterior cervical region, and evaluate potential statistical correlations with clinical and pathologic variables. Materials and Methods: The study included patients who had thyroid surgery. Morphologies, asymmetry, and patterns of the platysma were described. The analysis of the different considered variables was quantitative and qualitative, using multiple data reports. Results: A total of 23 men and 90 women, aged 19 to 70 (median 41±19) years constituted the study cohort. Their neck circumference and height were 388.5±45 mm (334 to 479 mm) and 200±30 mm (160 to 270 mm), respectively. The hemi-platysmal muscle was bilaterally identified in 109 (96.4%). The mean platysmal thickness was 2.7±1.7 mm (range: 0.7 to 8.2 mm). The intermediate plane between the platysmal muscles was classified into 4 types, depending on the muscle features in the midline: Type A: the left and right platysmal fibers were interlaced with each other in the midline (7%); type B: the platysmal fibers were disconnected by <1 cm (27%); type C: between 1 and 3 cm (52%); and type D separated >3 cm (14%). Conclusions: We provide descriptive characteristics of the cervical platysma. A better understanding of the anatomic variability in cervical platysma may be useful in performing a more accurate dissection in endoscopic endocrine neck surgery.