Subcutaneous fat layer in different donor regions used for harvesting microvascular soft tissue flaps in slender and adipose patients

The aim of this study is to provide valid data concerning the thickness of the subcutaneous fat layer in seven donor regions which are most commonly used for soft tissue replacement in the head and neck region. Furthermore the study focuses on differences in thickness of this layer depending on the nutritional status and sex. In 100 volunteers the thickness of the subcutaneous fat layer was evaluated using ultrasound in seven potential donor regions: radial and ulnar forearm, lateral upper arm, scapular and parascapular region, abdominal/supra-umbilical region and the lateral calf. Volunteers were divided into 4 groups: male and female, slender (body mass index [BMI] <25) and adipose (BMI >30). Data obtained was compared and differences were proven to be statistically significant (Student's t-test, P<0.05). The largest thickness was found in the supra-umbilical region followed by the lateral upper arm whereas the ulnar forearm region had the smallest thickness. Depending on the BMI the supra-umbilical and the lateral upper arm regions showed the most wide variation. Depending on sex the most noticeable variation in thickness of the subcutaneous layer was seen in the lateral calf region with a significant larger tissue layer in females.