Final answer:
A stent is left in place following the anastomosis of a ureter during a ureteral reimplantation procedure to ensure free drainage of the kidney postoperatively and proper healing.
Step-by-step explanation:
Following anastomosis of a ureter during a ureteral reimplantation procedure, a stent is left in place to ensure free drainage of the kidney postoperatively. The ureters, which are completely retroperitoneal structures, play a crucial role in transporting urine from the kidneys to the bladder. After surgical procedures like ureteral reimplantation, a stent is often temporarily inserted to maintain patency and allow proper healing by facilitating the flow of urine. This is essential to prevent obstruction or strictures that can impede urine flow, which is propelled by peristaltic waves, and to ensure the proper functioning of the one-way valve mechanism created as the ureters pierce the bladder wall obliquely.