This article is more than 5 years old. Information may no longer be current.
Low episodic rate of retrograde ejaculation found after ALIF with rhBMP-2
Investigators suggested that endplate perforation may play a role in the incidence of the condition.
Click Here to Manage Email Alerts
DALLAS — In a study that was not sponsored by industry, researchers with Loyola University found a 1.4% overall episodic rate of retrograde ejaculation in men who underwent anterior lumbar interbody fusion with recombinant human bone morphogenetic protein-2.
“We felt that the use of recombinant bone morphogenetic protein-2 [rhBMP-2] was safe with respect to retrograde ejaculation,” Alexander J. Ghanayem, MD, said during his presentation at the North American Spine Society Annual Meeting. “Our episodic rate was two of 141 patients overall. If you look at levels that include L5-S1, it was 0.9%. If you looked at dose, we found no statistical difference whether we used 2.1 mg per single level vs. 4.2 mg.”
Past studies
Ghanayem noted that previous studies on retrograde ejaculation rates and rhBMP-2 use may have biased results due to corporate sponsorship. Therefore, he and John Santaniello, MD, conducted a retrospective review without corporate sponsorship of 148 men who underwent anterior lumbar interbody fusion during a 7-year period. The study authors performed the procedures and used a retroperitoneal exposure.
“You have to be careful of some of the rates that are quoted in the literature, the denominator [may include] men and women, which is not appropriate,” Ghanayem said.
A femoral ring allograft spacer was filled with an rhBMP-2 impregnated collagen sponge. The authors found no statistical difference in the rate of retrograde ejaculation when either 4.2 mg or 2.1 mg of rhBMP-2 was used.
Images: Ghanayem AJ
Ghanayem and Santaniello excluded patients who did not have surgery at L4-5 or L5-S1 levels or who had surgery performed without the use of rhBMP-2.
Although four patients had preoperative erectile dysfunction, Ghanayem said fusion surgery did not affect their condition. According to the study abstract, two elderly patients (aged 67 years and 78 years) choose not to discuss ejaculatory/sexual function preoperatively and were excluded from the study. Another patient was excluded because surgeons abandoned using the retroperitoneal exposure during the operation. Overall, two of the 141 remaining patients (1.4%) had postoperative retrograde ejaculation, one of which resolved, leaving a permanent rate of 0.7%.
A post-surgical lateral radiograph illustrates the fusion construct that included a femoral ring allograft filled with rhBMP-2 and stabilized with an anterior plate.
Similar to literature controls
Ghanayem highlighted an FDA Investigational Device Exemption study and a study conducted by Eugene J. Carragee, MD, on this subject. The FDA Investigational Device Exemption study had corporate sponsorship and found no link between rhBMP-2 and retrograde ejaculation. The Carragee study, which did not receive corporate sponsorship, concluded that retrograde ejaculation was associated with rhBMP-2 use. Ghanayem said his study showed retrograde ejaculation rates that were similar to those of the control groups in the FDA and Carragee studies, noting that his study did not perforate the endplates in the surgeries, which “may play a role in increased incidence of retrograde ejaculation.”
“We do not know what is the rate of episodic vs. permanent retrograde ejaculation,” Ghanayem said. “There are other primary causes that have not been explored.” – by Renee Blisard Buddle
References:
For more information:
Disclosure: Ghanayem is on the Board of Directors of Loyola University Physicians Foundation, is on the Grant Committee of OMeGA, is the chair of AOA Investment Committee and receives research support for staff or materials from Synthes Spine. Santaniello has no relevant financial disclosures. Both authors and their immediate families have not been consultants, served on speakers bureaus, received stock/options, or royalties from the manufacturer of rhBMP-2.