What device supports the existing vessel from the inside?

• A. Balloon
• B. Stent
• C. Filter
• D. Catheter

Answer: (B)

A stent is a medical device that is specifically designed to provide structural support to a vessel from the inside. When blood vessels become narrowed or blocked due to conditions such as atherosclerosis, a stent is inserted into the affected area to keep the vessel open, allowing for improved blood flow. The stent maintains the integrity of the vessel wall and prevents it from collapsing after balloon angioplasty or similar procedures.

While balloons are used to dilate vessels temporarily and may lead to the placement of a stent, they do not provide long-term support. Filters, on the other hand, are typically used to trap embolic material and prevent it from traveling downstream in the bloodstream, but they do not support the vessel walls. Catheters are tools used for various medical procedures but do not provide structural support themselves. Thus, the stent is uniquely designed for this purpose, making it the correct answer.