The opposition Pakistan Muslim League-Nawaz (PML-N) party on Monday said that doctors treating Nawaz Sharif have advised that the former ailing prime minister should be shifted from London to the US for further medical treatment.PML-N spokesperson Marriyum Aurangzeb, however, said that shifting him from London to the US will be challenging for the medical team considering his current health condition.She also said that the medical reports of the former prime minister revealed that there was an 88 per cent blockage in arteries circulating blood to his brain, The Express Tribune reported."Doctors have advised him to consult an expert in the United States. However, transporting him there poses an immense challenge for the medical team," Aurangzeb was quoted as saying.The party's spokesperson stressed that Sharif will soon undergo a biopsy in light of his latest positron emission tomography (PET) scan and said that the platelet count of the ailing leader is showing no improvement."There ..