Zaa, agree with Creekimp13, Johns Hopkins is a world class medical facility so I would have no concerns about the hospital performing this procedure. It's an endoscope, relatively minimally invasive, so there's no incision to heal or be concerned with. What is more important IMHO is the doctor who will be performing this procedure on you.
Do you know who this would be? Are you familiar with their experience with ESG or Vertical Sleeve Gastronomy? Typical questions are how many procedures they have done? What is the rate and type of complications that their patients have experienced?
Feel free to ask questions we would be glad to help. Thx Tex