L-carnitine as primary or adjuvant treatment in infertile patients with varicocele. A systematic review

Abstract

Background: Varicocele has been found to impair the function of the epididymis resulting in subfertility whereas the varicocelectomy can resolve the phenomenon. L-carnitine is regarded as a biomarker for the function of the epididymis and has been found in reduced concentrations in infertile patients of various causes, including infertile men with varicocele. It seems that L-carnitine and varicocele share clinical significance and the area of research looks promising. Objective: To identify the role of L-carnitine in the treatment of varicocele. Materials and methods: A systematic search was performed in Pubmed/Medline with the terms (L-carnitine) and (varicocele) and (L-carnitine) and (varicocelectomy). Inclusion criteria were studies reported outcomes of L-carnitine administration alone or in duet, as primary or adjuvant treatment to varicocele. Exclusion criteria were non-English language and animal studies. Studies using L-carnitine as part of a panel of therapeutic agents were avoided. Results: Only four suitable studies were identified for discussion. In one randomized study, the combination of L-carnitine and cinnoxicam improved semen parameters in patients with non-high-grade varicocele compared to L-carnitine alone and had a favourable effect on pregnancy rates but the effect of grade is unknown. In another study, as an adjuvant treatment to varicocelectomy, L-carnitine showed no clear benefit. Finally, in comparison to surgery, the results are inconclusive; two studies showed some benefit might be expected in low-grade or subclinical varicocele, but surgery appears superior. Conclusions: The evidence regarding the role of L-carnitine as a primary or adjuvant treatment of varicocele is sparse. The pathophysiological significance of L-carnitine implicates a potential role of the molecule in the management of varicocele, but the evidence so far is controversial for any recommendations. L-carnitine might be taken into consideration in selected cases; however, further search is needed in order the optimal role of L-carnitine in infertile patients with varicocele to be clarified.