Effect of Electrical Stimulation of Medial Popliteal Nerve On Caliber of Renal Arteries in Unanesthetized Man

Abstract

Since the studies of Bywaters et al. (12)(13)(14)(15)(16)(17) upon renal failure in man following prolonged crush of the thigh(s), interest has been shown in stimulation of the sciatic nerve of animals with the view that this excitation may be contributory to renal shutdown of the &dquo;crush syndrome&dquo;. We undertook stimulation of a major branch of the sciatic in unanesthetized cooperative human subjects, most of whom had normal or near-normal kidneys. This was done in the course of translumbar aortography (renal arteriography) which supplemented the usual diagnostic armamentarium partly because most of the cases had &dquo;idiopathic&dquo; gross hematuria and we were doing our utmost to rule in or out renal neoplasm (cf. Maluf (42)) for validity of this concept. TECHNIQUEOur method of translumbar aortography in unanesthetized patients has been described elsewhere (42). The cathode-tube was centered directly over the expected site of origin of the renal arteries from the aorta, i.e. at Ll/L~. The kidneys thus appear about the middle of the film. In the present study special care was taken to infiltrate only the skin and subcutaneous tissue with the analgesic, 0.5 per cent procaine HCI. After considerable experience with translumbar aortography it has become possible to enter the aorta painlessly with local anesthesia applied only thus. The exposure-time for obtaining each radiogram was 0.25 sec.The patient was given 200 mg. of sodium luminal subcutaneously as a mild hypnotic half an hour before the first aortogram. Five to 10 minutes before the first aortogram meperidine HCI, 100 mg., was administered intravenously as a general analgesic. The first aortogram was obtained by injection of 35 cc. of 70 per cent Urokon (Na 3-acetylamino-2 , 4 , 6-tri-iodobenzoate) in about three seconds, or as rapidly as possible. The needle was then withdrawn about 3 cm. and its obturator completely re-inserted. The patient was requested not to move in the slightest from his position. He was warned of every step about to be taken and of what he probably would feel, thus preventing alarm and movement on his part. The left or right medial popliteal (posterior tibial) nerve was then stimulated percutaneously in the popliteal fossa for thirty minutes. The electrical stimulator, thyratron-type, was obtained by the courtesy of L. A. Geddes, from the