Cremaster muscle thickening: the anatomic difference in men with testicular retraction due to hyperactive cremaster muscle reflex

The objective was to assess whether men suffering from testicular retraction secondary to hyperactive cremaster muscle reflex have an anatomic difference in the thickness of the cremaster muscle in comparison to men who do not have retraction. From March 2021 to December 2021, 21 men underwent microsurgical subinguinal cremaster muscle release (MSCMR) on 33 spermatic cord units, as 12 of them had bilateral surgery, at Surgicare of South Austin Ambulatory Surgery Center in Austin, TX, USA. During that same time frame, 36 men underwent subinguinal microsurgical varicocele repair on 41 spermatic cord units, as 5 were bilateral for infertility. The thickness of cremaster muscles was measured by the operating surgeon in men undergoing MSCMR and varicocele repair. Comparison was made between the cremaster muscle thickness in men with testicular retraction due to a hyperactive cremaster muscle reflex undergoing MSCMR and the cremaster muscle thickness in men undergoing varicocele repair for infertility with no history of testicular retraction, which served as an anatomic control. The mean cremaster muscle thickness in men who underwent MSCMR was significantly greater than those undergoing varicocele repair for infertility, with a mean cremaster muscle thickness of 3.9 (standard deviation [s.d.]: 1.2) mm vs 1.0 (s.d.: 0.4) mm, respectively. Men with testicular retraction secondary to a hyperactive cremaster muscle reflex demonstrate thicker cremaster muscles than controls, those undergoing varicocele repair. An anatomic difference may be a beginning to understanding the pathology in men who struggle with testicular retraction.