This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'The best cosmetic results for large capillary (port wine) hemangiomas are achieved by - \nSelect and explain. \nA. Excision and split-thickness skin, B. Laser ablation, C. Cryosurgery, D. Tattooing', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Pulsed dye laser (PDL) therapy is considered the standard of care for the treatment of capillary malformations. It is based on the concept of selective photothermolysis.. The beam is selectively absorbed by red- pigmented material such as hemoglobin in the blood vessels of the lesion. This produces selective heat destruction of capillary vessel walls with minimal damage to the overlying epidermis, which leads to the lightening of the port wine stain without scarring.\n"The best treatment to date for early and intermediate port wine stains is with the pulsed dye laser. The method of treatment is termed selective photothermolysis. The beam is selectively absorbed by red- pigmented material such as haemoglobin in the blood vessels of the lesion. This produces selective heat destruction of these structures, and the treated area becomes whiter."- CSDT 13/e\nCapillary malformations (port wine stains or nevus flammeus)\n\nCapillary malformations (port wine stains or nevus flammeus) are low-flow vascular malformations of dermal capillaries and postcapillary venules.\nThey are present at birth as blanchable pink to red patches.\nThey may be located anywhere on the body, most commonly on the face, typically with a unilateral or segmental distribution that respects the midline.\nOn the face, they tend to follow the distribution of the trigeminal nerve branches (segments V1 , V2 , and V3 )\nCapillary malformations do not regress, but grow in proportion to the child\'s growth and become thicker and darker in colour during adulthood.', 'role': 'assistant'}]