A Posterior Transosseous S1 Pedicle Approach for Accessing the Superior Hypogastric Plexus: A Hypothesis

Chronic pelvic pain remains a significant clinical challenge, often refractory to conservative and interventional treatments. Superior hypogastric plexus block is an established technique; however, conventional anterior and posterior approaches may be limited by anatomical variability and potential risks to adjacent structures. Based on these anatomical findings, we propose that a posterior transosseous S1 pedicular approach represents a novel and anatomically robust corridor for accessing the superior hypogastric plexus. We hypothesize that the highly reproducible osseous anatomy of the S1 pedicle, combined with its consistent spatial relationship to the anterior sacral cortex and retroperitoneal compartment, may enable precise and fluoroscopically reproducible instrument guidance toward the plexus. Furthermore, this trajectory may mitigate the anatomical variability and procedural limitations associated with conventional anterior or paravertebral techniques while potentially reducing the risk of inadvertent injury to adjacent visceral, vascular, and neural structures. This concept is based on anatomical reasoning and fluoroscopic observations obtained during cadaveric anatomical orientation, suggesting that a transosseous trajectory through the S1 pedicle toward the anterior sacral cortex may offer improved spatial control and reproducibility compared with soft-tissue-based approaches. The proposed pathway remains conceptual and is not intended for clinical application at this stage. Further cadaveric, imaging-based, and clinical studies are required to evaluate its anatomical validity, safety, and potential clinical relevance.