Clinical Application of Botulinum Toxin A for Calf Hypertrophy Followed by 3-Dimensional Computed Tomography

Sir,

Body contouring is one of the rising trends in cosmetic fields, globally. Chubby and muscularly shaped legs are of particular cosmetic concern. For contouring enlarged calves, botulinum toxin A therapy may be a simple alternative to surgery without interrupting daily life, provided that this procedure achieves an appropriate, reliable reduction in muscle thickness.¹ There are several methods to evaluate the effect of treatment result such as visual assessment by experts, evaluation of patients’ subjective satisfaction, and comparison of the muscle volume before and after treatment. To measure the volume of muscle, you can try to check the circumference of muscle mass, calculate the volume by image guided reconstruction, etc.² This report describes a case of calf hypertrophy treated with botulinum toxin A, which was found to be an effective method with satisfactory esthetic results and clinical outcome followed by 3-dimensional computed tomography (3D-CT).

A 28-year-old Korean woman complained of gastrocnemius muscle hypertrophy and came to the clinic for a reduction of her calves. We decided to attempt a botulinum toxin A injection for calf contouring. After sterilizing the skin, aliquots of 100 units of botulinum toxin A (NABOTA, Daewoong; Seoul, Korea) in a diluent of 2.5 ml were injected on both sides of each gastrocnemius muscle. A total dose of 200 units of botulinum toxin A was administered to each calf. Clinical photographs were taken in a standing position on a flat floor to show the legs in a relaxed state and on the tiptoes to show a contracted state. Three follow-up evaluations were planned at 1-month intervals. A digital camera and 3D-CT were used to measure the volume of the gastrocnemius muscle.

After 1 month, the size of the gastrocnemius muscle was reduced bilaterally. The volume (cc) of the gastrocnemius muscles was also reduced according to 3D-CT (Fig. 1). The reduction in calf size was noticeable after only 1 month, and the effect was well maintained during the 3 months of continued follow-up. Leg contouring was obtained by the botulinum toxin treatment, and no functional disabilities were observed.

Fig. 1.

3D-CT shows a reduction in the volume of the gastrocnemius muscles over time. Preinjection and 1-month, 2-month, and 3-month postinjection views.

The contour of the posterior side of the legs is determined by the gastrocnemius and soleus muscles. The surface contours of the legs are most directly attributable to the superficially located gastrocnemius muscle. Commonly, the medial head of the gastrocnemius muscle forms a prominent contour medially in the posterior aspects of the legs in Asian women.³ With regard to assessing the clinical efficacy of botulinum toxin A, serial photographs and a circumference measurement seemed to yield reliable information on calf contour in clinical practice in most cases because of simplicity and convenience. In the reporting physician’s experience, 3D-CT is an accurate and standardized way to measure the volume change of the gastrocnemius muscle, although it would be difficult to justify in terms of cost-benefit calculations. We recommend 3D-CT scans, concomitant with serial photographs, as a useful tool in clinical study for comparing before and after results regarding muscle hypertrophy, especially calf muscle.

ACKNOWLEDGMENTS

This study was supported by the Infrastructure Program for New-Growth Industries (10044186, Development of Smart Beauty Devices Technology and Establishment of Commercialization Support Center) funded by the Ministry of Trade, Industry & Energy (MI, Korea).