Biopsy of Vastus Lateralis Muscle
This is Richard Allen at the University of Iowa. This video demonstrates biopsy of the vastus lateralis in a patient with suspected mitochondrial myopathy. A marking is made on the lateral portion of the thigh over the palpated vastus lateralis. An incision is made with the 15 blade through the skin and underlying subcutaneous fat. Metzenbaum scissors are then used to bluntly dissect through the fat to the underlying fascia. Double prong skin hooks are used to aid in exposure. The fascia is then visualized with the aid of cotton-tipped applicators. A 15 blade is then used to make incisions into the fascia in order to lift a window of fascia. The underlying muscle can then be identified. Metzenbaum scissors are used to dissect parallel to the fibers of the muscle. A muscle clamp is then introduced and secured so that the sarcomeres retain their anatomic position. Metzenbaum scissors are then used to harvest the specimen. Usually a pathologist specially trained in muscle pathology is needed to examine the specimen. Hemostasis is assured. The fascia can then be closed with 4-0 monocryl suture. The wound is then closed with interrupted deep 4-0 monocryl or vicryl suture. The skin can then be closed with interrupted 5-0 prolene sutures placed in a vertical mattress fashion. Again, this incision is made in the area of the vastus lateralis in a position very similar to where an incision would be made for harvesting fascia for a frontalis sling. The sutures will be removed in approximately one week. Antibiotic ointment is then placed over the incision, and the area is dressed with Telfa followed by Tegaderm.