Introduction
Deep rectovaginal endometriosis nodules in young women may involve
pelvic nerves, particularly when there is infiltration of the
parametrium, with or without adjacent vagina, rectum or ureters.
Parametrial nodules may compress, surround or infiltrate nerves of large
diameter, such as sacral roots, sciatic or pudendal nerves, or thin
fibres such as splanchnic or hypogastric nerves and the inferior or
superior hypogastric plexus. Depending on the role of nerve fibres,
somatic and vegetative symptoms may occur, such as pain in buttocks,
legs or perineum, skin hypo or hyperesthesia, bladder and rectal
dysfunction or vaginal dryness. These relatively rare symptoms may be
overlooked by gynaecologists or considered unrelated to nerve
involvement in a severe endometriosis1.
Over the past two decades, several authors have reported series of
patients surgically managed for endometriosis with various degrees of
involvement of sacral roots and the sciatic nerve1-3.
Large diameter nerve involvement generally occurs in two main ways,
which in some patients may be associated. i) The first and most frequent
situation concerns large rectovaginal or uterosacral nodules, which
develop laterally through the parametrium to the lateral pelvic wall,
pyriformis and levator ani muscles, where they come into contact with
the sacral plexus (Fig 1a). These nodules involve not only the sacral
roots, but also the inferior hypogastric plexus, splanchnic and
hypogastric nerves, as well as low rectum, vagina or homolateral ureter.
Patients presenting with this type of nodule usually present bladder,
rectum and left colon dysfunction in addition to vaginal dryness, more
likely due to the involvement of the inferior hypogastric plexus and
thin nerves than to that of sacral roots. They may also report somatic
pain, particularly in the buttock, perineum and leg, due to involvement
of sacral root S2, S3 and S4, which send fibres into the sciatic and
pudendal nerves; ii) the second less frequent situation involves deep
endometriosis nodules which occur more laterally and cranially, in
contact with the pelvic wall and sciatic nerve, before exit through the
greater sciatic foramen (Fig 1b). Patients present somatic, sensory
(buttock and leg pain) and motor complaints (alteration of the Achillean
reflex and foot drop, due to involvement of S1). Conversely, they
usually have no vegetative symptoms, due to no involvement of
sympathetic hypogastric nerves and parasympathetic fibres originating
from S2-S4, and no associated infiltration of rectum, ureters and
vagina4.
Outcomes of surgical management of deep endometriosis infiltrating the
large nerves have been reported by several authors in the literature,
and considered satisfactory in the majority of
cases1,2,4. To further knowledge in this field, our
study aimed to assess preoperative complaints, intraoperative findings,
surgical procedures and postoperative outcomes in a series of
consecutive patients managed for deep endometriosis involving sacral
roots and the sciatic nerve.
Patients and methods
We enrolled in this series all patients with deep endometriosis
involving sacral roots and the sciatic nerve, who had benefited from
surgical management carried out over 40 consecutive months from October
2016 to April 2019 at Rouen University Hospital, the Endometriosis
Centre, Clinique Tivoli-Ducos, Bordeaux, France and Aarhus University
Hospital, Denmark. Inclusion criteria were: i) deep endometriosis nodule
with limits that come into contact with, entrap or infiltrate sacral
roots or the sciatic nerve shown on pelvic MRI, in axial, coronal and
sagittal views; ii) presence of vegetative (bladder, rectal dysfunction)
or somatic complaints (pain in the leg, buttock or perineum; motor
weakness) attributable to pelvic nerve involvement; iii) surgical
procedure requiring complete dissection, shaving or intraneural excision
of endometriosis of sacral roots or sciatic nerve; iv) patient inclusion
and follow up in CIRENDO database. Exclusion criteria were: i)
non-French nationality and non-English speaking patients, ii) patients
not fulfilling at least one inclusion criteria.
All patients were preoperatively examined by a gynaecologist surgeon
whose practice exclusively focuses on deep endometriosis (H.R).
Preoperative assessment was performed by radiologists with considerable
experience in deep endometriosis and included pelvic MRI, along with
endorectal/transvaginal ultrasound, computed tomography based virtual
colonoscopy, uro-CT or uro-MRI when required. Urodynamic assessment was
performed in patients with baseline symptoms suggesting significant
bladder dysfunction. Surgery was proposed in patients for whom symptoms
were not relieved by medical therapy. Principles of surgical approach
were preoperatively discussed, and patients were fully informed about
the aims, risks and expected benefits of the surgery.
All patients were managed laparoscopically. The approach for deep
endometriosis infiltrating the parametrium down to the sacral plexus is
standardised (Supplemental Video 1) and follows successive steps: 1)
ureterolysis; 2) opening of the pararectal space on contact with the
rectum in a sagittal plane; 3) dissection prolonged toward the
rectovaginal space, including the section of rectovaginal nodules in one
fragment infiltrating the rectum, and another infiltrating the vagina
and the parametrium, down to levator ani muscles; 4) dissection of
presacral space, identification of the superior hypogastric plexus and
hypogastric nerve; 5) incision of the peritoneum at promotorium level,
prolonged laterally above the origin of hypogastric vessels; 6)
anterograde dissection of hypogastric artery and identification of
hypogastric vein; 7) anterograde dissection of hypogastric vein and
opening of Okabayashi space, successive identification and when
required, ligation of pelvic veins reaching the hypogastric vein. This
step is of major importance because the surgeon should be able, at any
moment, to ligate the hypogastric vein in case of dissection-related
injury; 8) dissection is prolonged behind venous network, with
identification of pyriform muscles and sacral root S2, S3 and S4, as
well as that of splanchnic nerves originating from sacral roots and
reaching the inferior hypogastric plexus; 9) anterograde dissection of
the nerve network and inferior hypogastric plexus, up to posterior
limits of the deep endometriosis nodule; 10) excision of deep
endometriosis nodule, from the posterior limit, to the inferior limit on
contact with sacral roots, which should be released or shaved, then to
the lateral limit on contact with pyriform muscle and lateral pelvic
wall. During this step, dissection is less standardised, and follows
nodule limits step by step, with sacrifice of involved fibres depending
on inferior hypogastric plexus and ligation of several parametrial
veins; 11) excision of adjacent vaginal infiltration; 12) removal of
rectal infiltration using shaving, disc excision or segmental resection.
Management of deep endometriosis nodules infiltrating the sciatic nerve
employs a different approach, laterally from external iliac vessels (5).
The procedure includes the following steps (Supplemental Video 2): 1)
longitudinal incision of the peritoneum covering external iliac artery;
2) opening and dissection of the space identified laterally by the psoas
muscle and medially by the external iliac artery and vein; 3) the
dissection progresses more deeply, with identification of the obturatory
nerve which is pushed medially, on contact with the psoas muscle; 4)
opening of the lumbosacral space, below the level of obturatory nerve,
and identification of the sciatic nerve, resulting from the confluence
of L5, S1 and S2 roots. During this step the deep endometriosis nodule
is identified; 5) dissection of the nodule, in lateral direction on
contact with the muscle, up to the greater sciatic notch; 6) removal of
the nodule by progressive dissection on contact with sciatic nerve;
haemostasis of surrounding gluteal veins should employ clips as
coagulation may be imperfect and veins may retract after section,
resulting in hidden bleeding which may be challenging to control; 7)
complete removal of nodule allows exposure of pudendal nerve, located
medially and caudally, just before its exit through the lesser sciatic
foramen.
Associated localisations of the disease were managed during the same
procedure. We performed shaving, disc excision or segmental resection to
remove colorectal nodules, depending on nodule
features6. Deep endometriosis responsible for stenosis
of ureters was managed by ureterolysis or ureteral resection, followed
by either end-to-end ureteral anastomosis or reimplantation of the
ureter into the bladder, depending on the extrinsic or intrinsic
infiltration of the ureter. Ovarian endometriomas were treated by
vaporisation using plasma energy, cystectomy, sclerotherapy or drainage,
depending on ovarian reserve and further intention to conceive. Other
endometriosis localisations were routinely removed by excision, until
all macroscopic lesions were treated. Following the procedure, the
surgeon completed a surgical questionnaire with responses recorded in
the CIRENDO database. An item “sacral plexus involvement” allowing
recording of patients managed with this localisation was added in
January 2016.
Postoperative hospitalisation varied from 4 to 6 days. Clinical symptoms
and body temperature were recorded 3 times/day, and assessment of blood
values of C-reactive protein (CRP) and white blood cells (WBC) was
routinely performed at day 4, 5 and 6. Administration of pregabalin by
progressive doses began day 1 after surgery and stopped after two weeks,
only if neuropathic pain, paraesthesia or hypo/hyperaesthesia were
completely absent. The urinary catheter was removed on postoperative
days 1 or 2 and post-voiding bladder residue (PVR) was recorded using an
ultrasonic bladder scanner (BladderScan BVI 6100, Verathon Inc, Bothell,
WA, USA) after each spontaneous void or every 4 hours. Any PVR greater
than 100 mL was considered abnormal and further bladder scanning was
performed. If PVR was greater than 400mL, the bladder was emptied using
an ‘in out’ intermittent catheter. If the patient was completely unable
to urinate, routine intermittent catheterisation was carried out 5 times
per day (at 7am, 11am, 2:30 pm, 6pm and 10pm). When PVR remained high
(over 100-150 ml) 3 to 4 days after surgery, patients were asked to
perform intermittent self-catheterisation 5 times per day following
discharge. Alfuzosine 10mg/day was prescribed for 3 months to reduce
urethral opening pressures. One month postoperatively, patients were
seen with a 48-hour record of urinary volumes voided spontaneously or
drained via self-catheterisation. If PVR was less than 100ml,
self-catheterisation was ceased; if PVR was greater than 100ml,
self-catheterisation was continued for a month or more.
PVRs during hospitalisation and during the period of
self-catheterisation were carefully recorded in patient medical charts.
Postoperative complications and the duration of self-catheterisation
required were recorded in the CIRENDO database, as well as follow up
data (pain, desire to conceive, pregnancies, standardised questionnaires
on gastrointestinal and urinary outcomes and quality of life).
Prospective recording of data concerning antecedents, clinical symptoms,
findings of clinical examinations and diagnostic imaging, surgical
procedures and postoperative outcomes was performed through the CIRENDO
(North-West Inter Regional Female Cohort for Patients with
Endometriosis) database (NCT02294825). This prospective cohort is
financed by the G4 Group (The University Hospitals of Rouen, Lille,
Amiens and Caen) and coordinated by one of the authors (H.R.).
Information was obtained using self-questionnaires and surgical and
histological records, while data recording, contact and follow-up were
carried out by 2 clinical research technicians. To ensure follow up,
women enrolled in the database were asked to answer questionnaires 1, 3,
5, 7 and 10 years after surgery. Standardised gastrointestinal
questionnaires were routinely used to assess pre- and post-operative
digestive and urinary function: the Gastrointestinal Quality of Life
Index (GIQLI)7, the Knowles-Eccersley-Scott-Symptom
Questionnaire (KESS)8, the Wexner anal continence
score9 and the Urinary Symptom Profile scale
(questions 8th, 9th and
10th exploring bladder
dysfunction)10. Quality of life was assessed using the
SF-36 score11. Prospective recording of data was
approved by the French authority CCTIRS (Advisory Committee on
information processing in healthcare research).
Statistical analysis was performed using Stata 11.0 software (StatCorp).
Patient characteristics, surgical procedures, postoperative outcomes and
score values were presented as numbers and percentages (qualitative
variables) or mean and SD (continuous variables). Comparison between
baseline and 1-year follow up data was performed using paired Student t
test (continuous variables) and McNemar test with correcting for
continuity (qualitative variables). The study was approved by the Rouen
University Hospital Institutional Ethics Committee for
Non-Interventional Research (E2020-21, April 13, 2020).