Neurovascular Architecture of Deep Endometriosis and Postoperative Pain Outcomes after Butterfly Peritoneal Excision: A Prospective Pilot Study.

STUDY

OBJECTIVE

To evaluate the neurovascular architecture of deep endometriosis using a standardized butterfly excision approach and to explore its association with postoperative pain outcomes.

DESIGN

Prospective exploratory pilot study.

SETTING

Tertiary referral center specializing in endometriosis surgery.

PATIENTS: Fifteen women with advanced posterior deep endometriosis undergoing laparoscopic excision.

INTERVENTIONS: Standardized butterfly peritoneal excision with systematic radial sampling from the central lesion to the peripheral peritoneum.

MEASUREMENTS AND MAIN

RESULTS

Each specimen was divided into 15 segments (7 per side plus central lesion), yielding 240 total samples, including normal peritoneum. Nerve-fiber density showed a significant center-to-periphery decline (β = -0.3169, p <.001), corresponding on average to an estimated 27% reduction per segment, while capillary density demonstrated a parallel but less pronounced decrease (β = -0.100, p <.001), supporting a coordinated neurovascular gradient. No right-left difference was observed. In contrast, tissue pain mediators exhibited heterogeneous spatial distribution rather than a uniform center-dominant pattern. Among evaluated markers, only bradykinin was associated with nerve-fiber density (p <.001). In exploratory multivariable analyses, central nerve growth factor concentration showed an association with 6-month dysmenorrhea improvement (β = 0.012, p = .043), whereas morphometric nerve-fiber density did not. For chronic pelvic pain, baseline pain severity was the only variable associated with postoperative improvement (β = 0.777, p = .030). Clinically, postoperative reductions were observed across multiple pain domains, accompanied by improvements in physical and mental quality-of-life measures.

CONCLUSION

Deep endometriosis demonstrated spatial neurovascular gradients with dissociation between structural innervation and inflammatory mediator distribution. Central neurotrophic activity showed an exploratory association with postoperative dysmenorrhea improvement, whereas morphometric nerve-fiber density did not. These findings support the feasibility and potential biological relevance of spatial neurovascular mapping in deep endometriosis and should be considered hypothesis-generating pending validation in larger studies.

CLINICAL TRIAL NUMBER: NCT06286371, https://clinicaltrials.gov/study/NCT06286371.

DATE OF REGISTRATION: 22.02.2024.