Review Question - QID 214477

A 58-year-old man presents to the emergency department for left leg pain and numbness. His symptoms began approximately 1 hour ago while reading a book at home. He denies any back pain or recent trauma to the back or leg. He has a past medical history of hypertension, hyperlipidemia, type 2 diabetes, and ischemic cardiomyopathy. He has been nonadherent to his medication regimen and does not follow-up with his primary care physician. Physical examination is notable for 4/5 strength in the left lower sensation with a mild but notable decrease to light touch sensation. There is a delayed capillary refill in the left lower extremity but normal in the right lower extremity. Arterial Doppler in the left lower extremity does not produce an audible pulse up to the left popliteal artery. In addition to intravenous unfractionated heparin, which of the following is the most appropriate next step in management?