Background Deep infiltrating endometriosis (DIE) is most commonly located at the uterosacral
ligaments, rectovaginal septum, pararectal space and vesicouterine fold. A nodule within the
uterosacral ligaments (i.e involvement of the dorsal parametrium), increases the complexity
of surgical resection. Parametrial involvement in DIE cases occurs in 25% of patients with
severe endometriosis, possibly with hypogastric/sacral plexus or sciatic nerve involvement.
The bladder functional impairment, after surgery for DIE involved the parametria, may vary
between the 6.5% to 32.8%. Preservation of the hypogastric and pelvic splanchnic nerves
represents the key aspect in pelvic surgery to prevent postoperative voiding disfunction.
Several techniques for the excision of DIE have been described, but large, prospective RCTs
are lacking. In particular, a clear standardization of the parametrectomy for DIE is missing.
Systematic reviews on the surgical treatment of DIE demonstrated that it is impossible to
compare the literature about the parametrectomy for DIE, because to unclear definitions and
lack of standardization. We therefore believe it is necessary to propose a standardization of
the definition of parametrectomy performed during procedures for DIE, to allow a clear
comparison in the future between scientific works on surgical treatment of DIE, as already
widely accepted in gynaecologic oncology with the classification of radical hysterectomy of
Querleu-Morrow. In particular we believe that the parametrectomy for DIE must be described
based on its anatomical extension and focused on the concepts of nerve sparing dissection,
and vascular structures preservation, to reduce the risk of complications due to ischemia
(i.e. ureter fistula).
Rationale A standardized description of the procedure (parametrectomy) will allow the
comparison between the different techniques in terms of functionality preservation of the
pelvic sympathetic and parasympathetic neural pathway. Therefore, the availability of a clear
classification able to define parametria involvement during surgery would be clinically
relevant, as they would allow to optimize counselling (risk of neurological consequences) and
surgery planning.
Type of the study Multicentric prospective observational study. Primary objective To
determinate the incidence of bladder functional impairment, after surgery for DIE involved
the parametria.
Secondary objectives To classify the parametrectomy into a clear system of classification,
based on anatomical landmark, and evaluate intra/postoperative complication to each classes
of proposed parametrectomy.
Sample size The sample size has been calculated on the basis of the primary objective; in
order to detect a proportion of bladder functional impairment of 30%, with a confidence level
of 95% and a margin of error of 9%, a sample of N=100 patients is required.
Inclusion criteria - Patient scheduled for surgery for DIE
Confirmation of DIE needed of parametrectomy at laparoscopic surgery Exclusion criteria
- Patients younger than 18 years and older than 50 years at time of operation
Refusal to answer the questionnaires
Absence of sexual activity
Diagnosis of multiple sclerosis
Pre-operative urodynamic diagnosis of neurogenic bladder dysfunction Statistical
analysis The sample will be described in its clinical and demographic characteristics
using descriptive statistics techniques. Qualitative variables will be summarized as
frequencies and percentages. Quantitative variables will be presented as mean (std.dev).
Normality of data will be checked with Kolmogorov-Smirnov test. The primary objective
will be achieved calculating the incidence of bladder functional impairment after
surgery. The secondary objective will be achieved using descriptive statistics
techniques already described.