22/05/2026
Parametrial endometriosis is a complex location of deep infiltrating endometriosis that is often associated with advanced disease, significant symptom burden, and challenging surgical management due to its proximity to critical pelvic neurovascular structures.
The parametrium refers to the connective tissue that surrounds the cervix. It is a complex bilateral anatomical region containing pelvic ligaments as well as vascular, lymphatic, and neural structures. Anatomically, it can be described in anterior, lateral, and posterior components. The posterior parametrium is a frequent site of lesion involvement (Ceccaroni et al. 2023).
This form of endometriosis is considered an advanced manifestation of the disease and is often surgically demanding due to the potential involvement of key anatomical structures, nerve fibers, pelvic vessels, and ureter. When localised at the parametrial level, deep infiltrating endometriosis may extrinsically involve the ureter. In some cases, ureteral involvement is extrinsic, and up to approximately one-third of patients may remain asymptomatic or present only with non-specific symptoms (Barra et al. 2024).
Disease extension may also include vascular elements such as the uterine artery and variable venous branches that may course near or over the ureter, the ureter itself, and neural structures including sympathetic fibers via the hypogastric nerve, parasympathetic fibers from the pelvic splanchnic nerves, and the inferior hypogastric plexus (Benoit et al. 2022).
Clinically, parametrial deep infiltrating endometriosis is associated with more severe symptom burden compared with other locations of deep disease. Patients frequently report more intense dysmenorrhea, increased urinary frequency or voiding dysfunction, and constipation. Preoperative findings also demonstrate significantly higher rates of severe dysmenorrhea (p < 0.001), urinary symptoms (p < 0.001), and constipation (p = 0.02) compared with patients with other patterns of deep infiltrating endometriosis (Mabrouk et al. 2019).