Retrograde Ejaculation, Male Sterility Linked to Medtronic InfuseFeb 27, 2012 | Parker Waichman LLP
A study published last year by Dr. Eugene Carragee, a prominent spinal surgeon and researcher with Stanford University, linked Medtronic Inc.'s Infuse bone growth product with retrograde ejaculation, a condition that causes male sterility. Dr. Carragee's study, published on The Spine Journal's website last May, found that men who underwent anterior lumbar fusion with Infuse developed retrograde ejaculation at a much higher rate than those who received a traditional bone graft.
According to a report from The New York Times, Infuse is used in about half of such procedures, and men make up about half of the patients who undergo spinal fusions.
“It is important that men who are considering having children have the opportunity to weigh the risks of the various available procedures,” said Dr. Carragee, according to The Times
Dr. Carragee's study involved 240 men who had undergone anterior lumbar fusion some years prior. Sixty-nine patients had received Infuse, while 174 had received the traditional bone graft. Five of the Infuse patients developed retrograde ejaculation, while one in the other group developed the condition. Of the six men who suffered retrograde ejaculation, only three experienced resolution.
Retrograde ejaculation is listed on the Infuse label as a possible side effect. However, according to The Spinal Journal report, this potential side effect is not widely known in the medical community.
According to The New York Times, Medtronic-paid doctors who worked on the clinical trials for Infuse purportedly found no connection between the product and male sterility, and instead blamed the problem on the surgical technique used to implant Infuse. While their studies specified which surgical technique was used in each of the men who suffered retrograde ejaculation, they did not indicate whether or not the patients had received Infuse. In his article Dr. Carragee questioned the decision not to specify which patients had received Infuse, asserting that was the standard way clinical trial results are presented.
Dr. J. Kenneth Burkus and Dr. Thomas A. Zdeblick, the researchers who conducted the Infuse clinical trial, have each received millions of dollars from Medtronic in consulting fees or royalty payments. Some have speculated that their financial relationships with Medtronic could have influenced the way trial data for Infuse was reported, though both have emphatically denied that was the case.
In an editorial accompanying Dr. Carragee's study, Dr. James D. Kang of the University of Pittsburgh mused that industry support was one way to explain the different conclusions reached by Dr. Carragee and the authors of the Medtronic-sponsored trial, writing that there was not "any rational explanation for these observational differences."