Yes, in ischemic priapism from PDE5 inhibitors, the glans penis is characteristically spared.
In ischemic priapism, the corpora cavernosa are typically affected while the corpus spongiosum and glans penis are not involved 1. This anatomical pattern is a defining feature of the condition regardless of etiology, including PDE5 inhibitor-induced cases.
Anatomical Pattern in Ischemic Priapism
The physical examination findings are distinctive:
- Corpora cavernosa: Fully rigid and tender
- Glans penis: Soft and uninvolved
- Corpus spongiosum: Unaffected
This pattern occurs because ischemic priapism is a compartment syndrome affecting only the paired corpora cavernosa, which become engorged with hypoxic, acidotic blood (PO2 <30 mm Hg, PCO2 >60 mm Hg, pH <7.25) 1.
Why the Glans is Spared
The glans receives its blood supply from terminal branches of the internal pudendal artery, providing redundant vascular supply that remains patent during the veno-occlusive process affecting the corpora cavernosa 2. The corpus spongiosum (which extends into the glans) has separate venous drainage that is not compromised in ischemic priapism.
Clinical Significance
This anatomical sparing is diagnostically important:
- Helps differentiate ischemic from non-ischemic priapism: In non-ischemic priapism, the entire penis including the glans may show partial tumescence 1
- Guides surgical intervention: Distal corporoglanular shunts work by creating a communication between the rigid corpora cavernosa and the unaffected glans/corpus spongiosum to allow drainage 1
The soft, uninvolved glans in the setting of rigid corpora cavernosa is a hallmark physical finding that should prompt immediate evaluation with corporal blood gas analysis 1.