Sandhi HouseでのThis term does not pertain to a surgical or medical procedure, so it doesn't fit the rules provided.

Please note that "Wellness retreats" is not a medical term for a clinical department or specialization in Japanese. Therefore, it does not have a direct translation under the specified guidelines for medical departments. However, if referring to a concept related to wellness programs or therapies in Japan, it might typically be translated or understood as "ウェルネスリトリート."