Dr. Brannigan is a Professor in the Department of Urology at Northwestern University, Feinberg School of Medicine with a clinical and research focus on male reproductive medicine and surgery. He obtained undergraduate and medical degrees from Northwestern University. After completing residency training in Urology at Northwestern, he entered a fellowship in Male Reproductive Medicine and Surgery at Baylor College of Medicine. He returned to join the faculty at Northwestern in 1999 where he is a Professor and Director of the Andrology Fellowship. Over half of his prior fellows now hold faculty positions at academic medical centers. Within Northwestern University, Feinberg School of Medicine, he serves as the Assistant Director of Student Affairs in the Augusta Webster Office of Medical Education.Dr. Brannigan has been actively involved in the leadership of many national organizations and societies. He is a Past President of the Society for Male Reproduction and Urology (SMRU) and also a Past President of the Society for the Study of Male Reproduction (SSMR). He has served on the Examination Committee for the American Board of Urology, the Core Curriculum Committee for the American Urological Association, and the Board of Directors for the American Society for Reproductive Medicine. He is an Editorial Editor for the journal Fertility and Sterility, a former Assistant Editor for The Journal of Urology, and an ad hoc reviewer for numerous other peer-reviewed journals.Dr. Branigan's clinical concentration is male reproductive medicine and surgery. His surgical interests include performing: microsurgical vasectomy reversal; microsurgical varicocelectomy; micro-TESE for sperm extraction; and vasectomy. He treats hypogonadism (low testosterone) in males, including hypogonadism associated with aging and congenital causes such as Klinefelter's syndrome. His primary research focuses on fertility preservation (oncofertility) in adolescent and adult male patients with cancer.