Keywords
endometriosis - deep endometriosis - #Enzian - laparoscopic surgery - ultrasound
Definitions and Symptoms
Endometriosis, which is the formation of clusters of endometrium-like cells outside
the uterine cavity, is currently subdivided internationally into three types: peritoneal
endometriosis,
ovarian endometriosis (endometrioma), and deep endometriosis (DE) [1]
[2]
[3]. The latter refers to clusters of endometrium-like cells penetrating more than 5 mm
below the peritoneum [2]
[4]. If the vagina, rectovaginal septum, bladder, bowel, ureter, diaphragm, or scars
are affected, these manifestations are considered by definition to be DE. It is estimated
that deep endometriosis occurs with a prevalence of 1–2% in the general population,
but there are only
sparse data available on this [5]. The symptomatology is as individual as the localization and the severity in the
patient are. The
primary symptoms of endometriosis, dysmenorrhea and chronic abdominal complaints,
also occur in the deep infiltrating type. Painful intercourse is common in patients
with vaginal or
rectovaginal endometriosis, dysuria may be indicative of bladder endometriosis, and
dyschezia can be a symptom of bowel endometriosis. However, this is by no means standard:
the correlation
between the symptoms and the anatomical characteristics of the disease is low [6]. Individual patients with an extensive case of
endometriosis show comparatively few symptoms and vice versa. Vegetative symptomatology
with nausea, vomiting, or cyclic diarrhea is often observed [7]. Despite the increased attention that the disease has received in recent years,
it takes an average of 8–12 years for a diagnosis to be made in Germany [8]
[9]. One of the consequences of long-standing endometriosis is chronic pain syndrome,
which is often no longer cyclical as the disease progresses; this can, in turn, lead
to depressive disorders. Anatomical changes and pro-inflammatory factors can result
in infertility and
early abortion [7]. It is also known that patients with DE more frequently suffer from complications
during pregnancy [10]. It is rare for a malignant tumor to develop on the basis of endometriosis (endometriosis-associated
malignancy, EAM): In the majority
of cases, these are endometrioid and clear cell ovarian carcinomas, but when it comes
to DE, these can also be malignant parametrial and rectal tumors [11]
[12].
Classification
The staging of the American Society for Reproductive Medicine (rASRM score) that was
introduced decades ago is still a common classification tool used today [13]. The extent of the endometriosis and the presence of adhesions and endometriomas
are taken into account and divided into stages I to IV
using a point system. The rASRM score focuses on the organs that are important in
terms of reproductive medicine, specifically the uterus, ovary, and the surrounding
area, yet endometriosis
affecting other organs is neglected. Thus, the extent of the disease is not fully
recorded; the system hardly correlates with the symptoms of affected patients. Furthermore,
it is an
inadequate tool for planning surgery, as surgeons are not given any indication of
the expected degree of difficulty of the procedure [2].
For that reason, the Stiftung Endometriose-Forschung (SEF) (Endometriosis Research
Foundation) inaugurated another classification system in 2003 specifically for deep
infiltrating
endometriosis [14]. The Enzian classification distinguishes between rectovaginal endometriosis (compartment
A), endometriosis of the
pelvic wall, the sacrouterine ligaments, and around the ureter (= extrinsic ureteral
endometriosis; compartment B), as well as endometriosis of the rectum (compartment
C). Endometriosis
growths in other locations are preceded by the abbreviation “F”, followed by the letters:
Since combining both classifications – rASRM and Enzian – is cumbersome in everyday
clinical practice, and is therefore often not done, the SEF has developed a completion
of the Enzian
classification, #Enzian, which now also includes endometriosis in the peritoneum (“P”),
the ovaries (“O”), the tubes (“T”), as well as secondary adhesions, making it possible
to describe the
endometriosis topographically in its entirety, as well as its extent and any other
organs affected [15]
[16]. The initial data collected have shown a correlation between #Enzian and the patient’s
symptoms as well as the extent of disease.
Further studies on this issue are being carried out [17]
[18].
The severity of the superficial peritoneal (< 5 mm depth of invasion) and ovarian
endometriosis is described as follows:
-
1: Sum of all lesions < 3 cm,
-
2: Sum of all lesions 3–7 cm,
-
3: Sum of all lesions > 7 cm.
“T” refers to tubo-ovarian adhesions or the mobility of the adnexa:
-
1: Adhesions between the tubes and the pelvic wall or tubo-ovarian adhesions,
-
2: T1 plus adhesions to the uterus or isolated adhesions to uterus,
-
3: T2 plus adhesions to the pelvic wall or bowel, or isolated adhesions to the pelvic
wall or bowel.
-
If tested, the patency of the tubes is indicated with a + or – symbol.
With the exception of peritoneal endometriosis, which is not adequately shown in imaging
and can thus only be classified surgically, the #Enzian classification is also suitable
for the
preoperative diagnosis of endometriosis. It can be classified preoperatively, both
with sonography (identified with the suffix “u”) and MRI (identified with the suffix
“m”), as well as intra-
and postoperatively (then based on the pathological examination of the surgical preparations;
identified with the suffix “s”). The preoperative assessment of the compartments (A/B/C/F)
in DE
by vaginal sonography (#Enzian “u”) corresponds to a high degree with the intraoperative
assessment of the severity of the disease (#Enzian “s”) [18]
[19]. Similarly sound results were also achieved when using the #Enzian classification
in the context of MRI
diagnostics [20]. As a common language for non-invasive and invasive diagnostics, #Enzian is intended
to form the foundation for improved
clinical and scientific work relating to patients with endometriosis [21]
[22]
[23]
[24]
[25] ([Fig. 1]).
Fig. 1 #Enzian – classification. Source: Keckstein J, Saridogan E, Ulrich UA et al. The #Enzian
classification: A comprehensive non-invasive and surgical description system for endometriosis.
Acta Obstet Gynecol Scand 2021; 100: 1165–1175.
Diagnostics
The basis for diagnosis, in addition to the often essential anamnestic recording of
symptomatology, is a clinical gynecological examination. During speculum insertion,
a deep infiltrating
growth can be seen in the vagina, especially when looking into the posterior fornix.
Deep infiltrating lesions of the rectovaginal septum, pouch of Douglas, and lower
rectum can often be
palpated during digital vaginal and rectal examination [2]. The examination should be repeated immediately before the operation under
anesthesia: the relaxed state often makes the findings even easier to feel. Endometriomas
and deep infiltrating growths in the bladder, the rectovaginal septum, and the deep
rectum can now be
visualized in detail using vaginal sonography [26]. The “sliding sign” allows conclusions to be drawn about adhesions, making it suitable
to detect obliteration of the pouch of Douglas [27].
If rectal endometriosis is suspected, rectal endosonography is a helpful alternative
to determine the size, position (from the anus), and infiltration depth of the growth.
A colonoscopy is
useful to determine other diseases of the bowel preoperatively with a differential
diagnosis. A colonoscopy is mandatory in the event of rectal bleeding and is required
by many visceral
surgeons for planned bowel resection [2].
Magnetic resonance imaging often provides an excellent depiction of the situation,
but is rarely required for clinical routine. However, it can show specific findings
such as bowel
endometriosis higher up, which is otherwise usually only diagnosed during surgery
[22].
Vaginal ultrasound is currently regarded as the standard tool in the preoperative
diagnosis of ovarian endometriosis, DE, and adenomyosis [28]. The ESHRE (European Society of Human Reproduction and Embryology) has been prompted
to no longer recommend laparoscopy with histological confirmation as a general
measure for diagnosing endometriosis, especially due to the good correlation between
the preoperative sonographic assessment and the intraoperative findings; based on
this, clinical vaginal
sonographic examination is sufficient if the symptomatology meets the criteria [19]
[29]. In contrast, the authors of the endometriosis guidelines of the German-speaking
countries have retained laparoscopy as the diagnostic standard [30]. If laparoscopy is not performed, it is essential for experts to carry out non-invasive
diagnostics with systematic evaluation and
description (classification) of the findings [28]
[31]
[32].
General Information on Surgical Therapy
General Information on Surgical Therapy
The decision to operate depends primarily on the clinical issues caused by the disease
and on the subjective psychological strain incurred. Asymptomatic patients do not
require treatment. If
the patient has pain, no desire to have children and no organ destruction, they should
first be treated with medication; however, in a study on this constellation, 80% of
patients reported
side effects [33]. Surgery is only considered the measure of choice if appropriate treatment with
medication fails, and is still
indicated in the event of suspected organ infiltration with loss of anatomical integrity
and/or function, or involuntary childlessness, especially in the case of symptomatic
endometriosis; in
the latter situation, a specialized center for reproductive medicine should be consulted
early on [30]
[33]. Doctors must inform the patient extensively about the operation and its potential
complications, as well as treatment alternatives, so
that the patient can make a conscious and sound decision [34]. Ultimately, the question of whether surgery should be performed can only
be answered individually: If doctor and patient come to the conclusion together that
the potential complications or consequences of the operation (including a protective,
temporary stoma) are
perhaps not as serious as the current situation, the indication is correct. A patient
suffering severely from dyschezia and painful intercourse caused by DE, and for whom
medication did not
help, certainly fulfills the requirements for surgery.
Having said that, there is a dilemma when it comes to the scope of the resection:
On the one hand, the treatment of all endometriosis growths eventuates in a significant
reduction in symptoms
and should therefore be the goal of the surgery [2]
[5]
[34]. On the other hand, anatomical changes due to the invasive progression of the disease,
extensive adhesions, and the accompanying
inflammatory reaction complicate surgical intervention – even for experienced surgeons.
If the rectum or rectovaginal septum are affected, this can lead to complications
such as anastomotic
failure or rectovaginal fistula formations. An injury to the hypogastric plexus or
the splanchnic nerves in the area of the sacrouterine ligaments during parametrial
preparation may lead to
disorders affecting the emptying of the bladder and bowel, as well as reduced sensitivity
in the vaginal area, which is why complete rehabilitation on both sides is avoided
in favor of
vegetative innervation; in any case, the vegetative nerve plexuses should be precisely
depicted and protected [31]
[35].
In order to avoid the occurrence of these complications, it is important to prepare
well for the operation: In addition to a strict indication, an interdisciplinary team
of gynecologists and,
depending on the affected organs, visceral surgeons, urologists, and thoracic surgeons
should be involved [34]. The operation must be
individually adapted to the severity of the findings and the corresponding symptomatology,
and treatment at a properly equipped center is recommended.
Preoperative bowel preparation is carried out in many centers – without there being
reliable data on this – in order to reduce contamination with intestinal germs in
case the intestinal lumen
opens, and to create more intra-abdominal space through an empty bowel [2]
[36].
There is, nevertheless, insufficient evidence that this reduces the complication rates
in endometriosis surgery [37]. Temporary
ovariopexy is a simple and uncomplicated technique to improve access to deep infiltrating
findings in the pouch of Douglas [38]. Tools,
such as uterine mobilizers or rectal probes, can also simplify the work [2].
Vagina, Rectovaginal Septum, (#Enzian A), and Rectum (#Enzian C)
Vagina, Rectovaginal Septum, (#Enzian A), and Rectum (#Enzian C)
Dysmenorrhea, painful intercourse, and dyschezia are the typical symptoms of deep
infiltrating endometriosis of the vagina and rectovaginal septum, which, due to continuous
growth, often
occur in combination with rectal endometriosis, which is why these three manifestations
are discussed together here [30]. Rectal,
cycle-synchronous blood loss (hematochezia) would be typical of rectal endometriosis,
but does not occur in all patients affected. In all patients with rectal bleeding,
it is necessary to
perform a preoperative colorectoscopy for diagnostic differentiation from other, primary
bowel diseases [30].
The aim of the operation is the complete resection of the affected area, as this improves
the patient’s quality of life [39].
The following are techniques to resect rectal endometriosis: rectal shaving, full
thickness wall excision (disc resection), or segmental resection.
-
Rectal shaving: Superficial resection of the endometriosis from the intestinal wall;
the lumen is not opened (although the literature usually does not define whether involvement
of the
muscular intestinal wall is to be taken into account).
-
Disc resection: Intestinal wall resection is performed, which e.g., can be done anally
with a circular stapler as a semi-circular resection.
-
Segmental resection: The relevant rectum segment is resected by means of GIA and the
corresponding ends are usually anastomosed transanally with a stapler. In the case
of very deep
anastomoses (5 cm and less from the anus), a temporary, protective ileostomy is created
in individual cases – especially in some centers.
Since complications such as anastomotic failure, rectovaginal fistulas, innervation
disorders of the bladder, and postoperative bleeding occur more frequently after segmental
resections, the
trend in recent years has been towards the less invasive shaving technique [33]
[40]. Some believe that not only superficial, but also most larger and deeper infiltrating
findings can be resected with this method, so that segmental resection is reserved
for very extreme cases with stenosis (> 80% of the lumen restricted) or growths on
the posterior rectal wall, which, however, are extremely rare [5]
[33]
[41]. However, there is a risk that the growth is not
removed completely during shaving and that symptoms may still persist after surgery
[42]. Contrary to previous assumptions, the methods
are equivalent in terms of the probability of recurrence [41]. Reviews, retrospective studies, and case control studies demonstrate that
avoiding a radical approach has better results in terms of operation-related morbidity
and the complication rate [43]
[44]; however, in the only randomized study on this topic, there was – contrary to expectations
– no significant difference [45]. In that sense, the decision must be made together with the patient and with clinical
judgment. Avoiding a radical approach when it
comes to DE, especially if the sacrouterine ligaments and the vagina are affected,
is the best way to minimize the surgical risks. If the vagina is opened, it can be
closed vaginally or
abdominally, depending on the type of operation. After extensive endometriosis resection
in the posterior compartment, especially with partial colpotomy, a cesarean section
should be discussed
as the type of delivery if the patient falls pregnant [30]. The postoperative risk of developing a fistula is greater if the vagina is
opened with a deep rectal suture at the same time ([Fig. 2]).
Fig. 2
a #Enzian C3 – Endometriosis: resection of the rectum with the linear stapler. b Same finding after resection; affected area totaling 12 cm (Martin Luther Hospital
Berlin,
Clinic for Gynecology and Obstetrics).
Bowel: Sigmoid Colon, Ileocecal Region, Appendix, Small Intestine (#Enzian FI)
Bowel: Sigmoid Colon, Ileocecal Region, Appendix, Small Intestine (#Enzian FI)
Endometriosis lesions in higher parts of the intestine can become noticeable through
symptoms such as dyschezia, tenesmus, obstipation, and diarrhea – also alternating
– but are often an
incidental finding during surgery as they go unnoticed in gynecological examinations
[30]. The vermiform appendix is most often affected,
and the sigmoid and cecum are also affected relatively often. A laparoscopic appendectomy
is performed to treat the former. Bowel endometriosis in other localizations can be
operated on by
means of ablation (shaving) if the growth is superficial. In the case of larger or
stenosing findings, the affected intestinal section is usually mobilized and moved
in front of the abdominal
wall by performing a mini-laparotomy, where it is worked on by hand in the traditional
way. The disease rarely leads to intestinal obstruction, which can be cause for emergency
surgery [46]
[47]. This complication can be triggered by hyperstimulation during assisted
reproduction (ART) [48].
Bladder (#Enzian FB)
Dysuria, pollakisuria with an imperative urge to urinate, pain in the area of the
symphysis, and (cycle-synchronous) hematuria can be symptoms of deep bladder endometriosis,
which affects
around 1–2% of patients suffering from endometriosis [30]
[49]. Endometriosis is
usually found on the posterior wall of the bladder and the fundus, where it presumably
originated as adenomyosis growths of the anterior wall of the uterus [2]. The bladder wall can usually be assessed well with sonography of the half-filled
bladder [28]. Prior to surgery, a cystoscopy is also useful, since the position of the endometriosis
growth, especially in relation to the ureteral ostia, can be specified and,
under certain circumstances, ureter splints can be placed preoperatively [50]. As is the case with growths in other localizations, the
aim of the operation is complete resection and restoration of organ integrity. Resection
– up to and including partial cystectomy – is the gold standard, as it has lower recurrence
rates
compared to transurethral resection [50]
[51]. A continuous detrusor suture is
usually placed extramucosally using monofilament suture [30]. Complications, which fortunately occur much less frequently than with
rectal surgery, can be secondary bleeding with bladder tamponade, suture insufficiency,
reduced bladder capacity, ureteral obstruction, or fistula formation, so that if other,
deep
endometriosis growths (e.g., rectovaginal, rectum) are present at the same time, a
two-stage surgical procedure is sensible and recommended. Overall, the surgical treatment
of bladder
endometriosis has good therapy results and is marked with pleasantly few complications
[51] ([Fig. 3]).
Fig. 3 Extensive bladder endometriosis after resection: In the foreground, the resected tissue
measuring a good 5 cm; view of the urinary bladder with catheter ball and double-J
stents on both
sides (Martin Luther Hospital Berlin, Clinic for Gynecology and Obstetrics).
Parametrium (#Enzian B) and Ureter (#Enzian FU)
Parametrium (#Enzian B) and Ureter (#Enzian FU)
Endometriosis of the pelvic wall, or the parametrium, manifests itself primarily in
pain and painful intercourse; if the growth is localized in specific areas (S2 root,
obturator nerve,
sciatic nerve), the pain can radiate to the respective leg or back. If the ureter
is compressed from the outside by deep endometriosis, this is referred to as an extrinsic
ureteral
endometriosis; if the ureter wall itself is infiltrated by the endometriosis, this
is referred to as intrinsic ureteral endometriosis. In most cases, a more distal section
of the ureter is
affected – and in the majority of cases, the left side [52]. Ureteral endometriosis is inevitably accompanied by endometriosis in the
pelvic wall or the parametrium, often also by deep infiltrating growths in other locations,
so that the typical endometriosis symptoms can occur in addition to flank pain. However,
generally,
the flanks do not show symptoms, which can lead to “silent urinary retention” with
loss of renal function [52]
[53]. Therefore, all patients who suffer from deep endometriosis should be offered a
renal ultrasound every six months to rule out urinary
obstruction, which is an absolute indication for treatment [30]. In the case of hydronephrosis, a urological diagnostic confirmation of
renal function should be carried out preoperatively (retention parameters, renal scintigraphy,
cysto-/ureteroscopy, MRI urography, excretory urography) [2].
Surgical treatment (prior to ureter splints), which aims to completely eliminate the
ureteral obstruction and thus preserve renal function, includes ureterolysis, if necessary
partial
ureteral resection with end-to-end anastomosis or, if distal, ureteral reimplantation
[54]. In a number of cases, extricating the ureter
from its lining involves dissection and resection of the pelvic wall. Also in the
case of intrinsic ureteral endometriosis, maximum decompression is worthwhile in most
cases, initially with
preservation of the ureter, since – with the splint in place – it can heal well; reflex
resection of the affected area with ureteroneocystostomy (psoas hitch, Boari) is not
recommended.
Therapy should take place in close cooperation with colleagues from the urological
department [51].
Diaphragm, Pleura, Lung Parenchyma (#Enzian F)
Diaphragm, Pleura, Lung Parenchyma (#Enzian F)
DE in these locations is collectively referred to as “thoracic endometriosis syndrome”
(TES), with diaphragmatic endometriosis accounting for 89% of these cases. Typical
symptoms are
shortness of breath, right-sided, cycle-dependent pain in the chest, shoulder, and
arm, so-called catamenial pneumothorax, which usually occurs on the right side, or
hemoptysis. Data suggest
that 55–100% of patients with diaphragmatic endometriosis also have pelvic endometriosis
[55]
[56].
The medical history, supplemented by MRI, laparoscopy, and, if necessary, thoracoscopy,
is the diagnostic foundation. The guidelines for the diagnosis and treatment of endometriosis
in
German-speaking countries recommend an initial medical treatment attempt for thoracic
endometriosis, and surgery only if this attempt is unsuccessful [30]. Superficial findings can be removed by means of ablation or resection, deeper growths
infiltrating the diaphragm or pleura should be completely resected. Most centers
suture laparoscopically with or without the postoperative insertion of an appropriate
chest drain. If large-scale diaphragmatic defects are found – especially if located
dorsally to the liver
– the thoracoscopic suture as part of a double-cavity procedure together with a thoracic
surgical team can, in the authors’ experience, be significantly easier and faster
(combined
laparoscopic and thoracoscopic; video-assisted thoracoscopic surgery, VATS). Potential
complications include a diaphragmatic hernia or injury to the phrenic nerve with paralysis
of the
diaphragm [55]. Hormonal suppression therapy is recommended after surgery for relapse prophylaxis
[29] ([Fig. 4]).
Fig. 4
a View of the right side of the chest (with collapsed lung and drain) after resection
of extensive, transmural diaphragmatic endometriosis. b Status post laparoscopic
suturing of the diaphragmatic defect; the liver is held caudally and dorsally (Martin
Luther Hospital Berlin, Clinic for Gynecology and Obstetrics).
Scar Endometriosis (#Enzian F)
Scar Endometriosis (#Enzian F)
Scar endometriosis typically occurs in the region of caesarean section scars, trocar
puncture sites, perineal tear and episiotomy scars, and causes cyclical pain in the
corresponding area.
The growth can often be easily palpated and visualized by means of sonography. In
individual cases, an MRI examination can be helpful [30].
A recent study in which Buscemi et al. managed to demonstrate that all of the 46 examined
patients with scar endometriosis had a history of a cesarean section corroborates
the theory of
origin of the iatrogenic spreading of cells [57].
The treatment of choice is complete resection, which can be performed using palpation
findings or wire marking. The latter can be helpful as the growth may be difficult
to locate once the
scar has been opened. Large fascial defects are often closed using mesh [2]. Laparoscopy in the same procedure is recommended to exclude
or resect intra-abdominal growths that are present at the same time. This also applies
to umbilical endometriosis, which is not necessarily treated surgically. For aesthetically
pleasing
reconstruction after resection, a plastic surgeon may need to be consulted [29].
Concluding Observations and Outlook
Concluding Observations and Outlook
In recent years, surgical therapy of DE has been characterized by an increasingly
individual approach. Depending on the symptoms, the involved organ(s), and potential
desire to have children,
the pros and cons of hormonal and surgical therapy must be discussed with each patient
in order to be able to make a sound decision together. The #Enzian classification
is now available for a
comprehensive, exact description of the manifestations. All the authors agree that
preoperative vaginal sonographic diagnostics have progressed to such an extent that
diagnostic laparoscopy is
no longer required to confirm the diagnosis. Patients benefit from treatment in an
appropriate endometriosis center with an experienced interdisciplinary team, which
will hopefully further
reduce the complication rates in the often complex operations. A certain reduction
in a radical surgical approach (e.g., less deep segmental resections in rectal endometriosis)
seems to be
observed, but precise data are not available on this. In order to achieve a good postoperative
quality of life, physicians should ensure a holistic treatment approach (multimodal
analgesia,
psychosomatic (medicine, symptoms, etc.)/psychotherapy, physiotherapy, complementary
treatment options). It is also our task as surgeons to better integrate these efforts
into everyday
clinical practice and to make them accessible to patients.
