Is it permissible, in Sharia, to seek the help of a relative who is a doctor to expedite a surgical appointment by having my appointment moved ahead of another person's, given that my scheduled appointment is very late?

If you predominantly believe that the doctor will place your file in the stead of someone who has relinquished their turn, then you have two scenarios:

1. If the assignment of patients' turns depends on the vacancy of the aforementioned person's turn, then it is not permissible for you to do so, as it infringes upon the right of another.

2. If the patients' turns are fixed by appointments that do not advance, and the regulations do not prohibit occupying this turn, and there is no one more deserving than you, then there is no blame upon you. The responsible authority for organizing appointments shall decide on this matter.