Final answer:
In medical procedures for bone marrow sampling or transplantation, the traditional needle placement has been near the iliac crest of the pelvic bones, chosen for its accessibility and safety.
Step-by-step explanation:
The medical procedure of bone marrow sampling or transplantation and where needles should be placed when an anastomosis is present. Traditionally, a large-bore needle would be inserted near the iliac crest of the pelvic bones for such procedures, due to its accessibility and the reduced risk of involving vital organs. However, the procedure is known to be quite painful. It is crucial in the medical field to choose needle placement carefully to minimize patient discomfort while ensuring the effectiveness of the procedure.