Intravenous methylene blue as an aid to intraoperative localization and removal of the adrenal glands during laparoscopic adrenalectomy

Background: We hypothesized that intravenous methylene blue will facilitate adrenal gland identification and resection during laparoscopic adrenalectomy. Methods: Five mini-Hanford pigs were anesthetized and monitored per an approved Internal Review Board protocol. Timing of color changes in the adrenals was recorded after administering methylene blue at three different doses: 2.5 mg/kg, 5.0 mg/kg, and 7.5 mg/kg. The time required for laparoscopic adrenalectomy with and without methylene blue was recorded. Results: No color change occurred after the 2.5 mg/kg dose. For the 7.5 mg/kg versus the 5.0 mg/kg dose there was a more rapid bluish color change (mean time, 1.89 minutes versus 3.45 minutes; P = 0.03) and a longer duration of bluish color change (mean time, 12.20 minutes versus 6.19 minutes; P = 0.01). Laparoscopic adrenalectomy using methylene blue resulted in a 34.5% faster median resection time (10.13 minutes versus 15.47 minutes). Conclusions: Methylene blue concentrates in the adrenal glands and facilitates identification and resection of the adrenal glands by a laparoscopic approach. (C) 2003 Excerpta Medica, Inc. All rights reserved.