Rigi10™ Malleable Penile Prosthesis
Also Known As
Erectores penis, erector clitoridis, ICM (Ischiocavernosus Muscle), Ischiocavernosus
Definition
The Ischiocavernosus muscle is a paired, superficial perineal muscle found in both males and females, located within the urogenital triangle just beneath the skin surface1,2. It originates from the medial aspect of the ischial tuberosity and the ischial ramus of the hip bone1,2. The muscle fibers then extend anteriorly, running along the medial aspect of the ischial ramus to surround the crus (the erectile tissue forming the base) of the penis in males or the clitoris in females, inserting into the lateral and inferior surfaces of these structures1,2.
The primary purpose of the Ischiocavernosus muscle is to contribute to sexual function, specifically in achieving and maintaining an erection of the penis or clitoris1,3. It works by compressing the crura of the penis or clitoris. This compression serves two main functions: it pushes blood from the roots of these erectile structures into their distal parts (the body of the penis or clitoris), and it simultaneously constricts the surrounding veins that would normally drain blood away from these structures1,3. This action effectively traps blood within the erectile tissues, leading to increased turgidity and rigidity, thus maintaining the erection during sexual arousal and intercourse1,3. In males, the Ischiocavernosus muscles also play a role in stabilizing the erect penis1.
Clinical Context
The Ischiocavernosus muscle (ICM) plays a crucial role in normal sexual function, particularly in achieving and maintaining penile or clitoral erection1,3. Clinically, its integrity is important, as injury to this muscle can lead to sexual dysfunction. Ischiocavernosus muscle injury (ICMI) has been identified as a factor associated with erectile dysfunction (ED)3, particularly in the context of pelvic trauma. Pelvic fractures, especially those involving the pubic ramus, ischial ramus, or causing pubic symphysis separation, are significant risk factors for ICMI3.
Patients presenting with pelvic fractures may be assessed for potential ICMI if they report symptoms of ED post-trauma. The diagnostic evaluation for ICMI can involve imaging techniques such as computed tomography (CT) or magnetic resonance imaging (MRI), and functional assessment through electromyography (EMG) to evaluate the muscle’s nerve supply and activity3. The extent of ICMI can influence the nature and prognosis of associated ED; for instance, unilateral ICMI has been linked to transient ED, whereas bilateral ICMI may result in more permanent ED3.
Understanding the clinical context of the Ischiocavernosus muscle is therefore important in the assessment and management of patients with ED, especially those with a history of pelvic injury. Surgical procedures in the perineal area must also consider the location and function of the Ischiocavernosus muscle to avoid iatrogenic injury. Expected outcomes following ICMI depend on the severity of the injury and any associated nerve or vascular damage, with some patients potentially experiencing recovery of erectile function, while others may have persistent deficits.