Deep endometriosis can affect the digestive system, infiltrating the various layers of the wall of the rectum, colon, small intestine and appendix.
The frequency of this type of endometriosis is difficult to accurately estimate. In a survey (1) conducted in 2015 in 56 French centers, it was estimated that in France more than 1,200 patients per year have surgery for endometriosis of the colon and rectum.
Probably the most frequent place that “non-gynecological” endometriosis is found involves the digestive tract. In the vast majority of cases it is located in the rectum and sigmoid colon. In less than 10% of cases, endometriosis lesions are also identified in the appendix, at the end of the small intestine (the last 30-40 cm), or the nearest part to the colon (caecum). In contrast, endometriosis lesions are very rare or absent in the stomach, duodenum, proximal and intermediate parts of the small intestine or on the surface of the liver and spleen.
Digestive lesions are single in around 2/3 of cases, and multifocal in around 1/3 of cases, where they may be separated by several centimeters of healthy bowel.
The lesions in the digestive tract may be superficial, 2-3 mm thick, and involve only the superficial layer of the intestine (the serosa, A), or larger and deeper, involving the muscular (B), submucosal or mucosal layers.
Deep nodules are responsible for considerable thickening of the digestive tract wall and by a proliferation of muscle cells which push the mucosa towards the digestive lumen. In about 2/3 of cases, infiltration stays at the muscular layer level, whereas crossing the mucosal layer is very rare (about 5%) occurring particularly with very large and practically sub-occlusive nodules. This explains why digestive nodules, even large ones, are not visible from inside the digestive tract, and why a colonoscopy can be interpreted as normal.
Digestive endometriosis nodules therefore infiltrate the digestive tract from the outside inwards, giving them a fan-shaped, an orange segment or mushroom appearance, with a base that is wider than the top. The base may be extended by infiltration of another organ (e.g., uterus, utero-sacral ligaments, vagina), resulting in an adhesion of the gastrointestinal tract to the involved organs (misinterpreted as simple adhesion).
In other cases, the digestive nodules may be solitary, with a base that may be easy or not to identify on the surface of mobile intestine.
It is important to understand that digestive endometriosis nodules are predominantly composed of muscular or fibrous tissue, while cells that resemble endometrial cells (hormone-dependent) constitute 15-20% of the volume of the nodule. This composition explains the minimal variations in digestive nodules (2) under the effect of amenorrhea, which in the majority of cases only leads to stabilizing the lesions, without them regressing.
The symptoms linked to digestive nodules can be very diverse with in particular levels of pain that vary greatly from one patient to another. Symptoms may not be painful and their insidious and slow appearance and evolution, can lead to considerable delay in diagnosis and management. In other cases, patients may be asymptomatic for a long time.
The onset of symptoms usually associated with several mechanisms (3):
Blood loss via the anus (rectal bleeding) is only exceptionally due to bleeding from digestive nodules. In the vast majority of cases, this occurs from hemorrhage of an internal hemorrhoid, developed due to chronic defecatory efforts. It mayt also be due to a colonic polyp.
Digestive symptoms can also be affected by other mechanisms, independent of infiltration of the digestive tract, which can theoretically persist despite complete surgery of digestive lesions:
Despite its limited effect on the size of the digestive nodules, amenorrhea allows significant improvement in digestive symptoms in a majority of cases. In a study carried out at Rouen University Hospital, digestive symptoms were found to disappear in approximately 50% of cases in women under medical treatment (7).
Nevertheless, menopausal women with large nodules of the digestive tract sometimes undergo surgery due to persistence of sub-occlusive symptoms lasting several years after the onset of the menopause.
Because of the low risk of complications, medical treatment is generally initiated as a first-line treatment, especially in women with no side effects and those not wishing to conceive.
Two surgical approaches for digestive endometriosis lesions:
It is important to offer patients with endometriosis the surgical treatment that is best suited to their situation, i.e. personalized or customized. Our team respects this principle, demonstrated by the overall balanced ratio between the three techniques used in current practice: shaving, discoid resection or colorectal resection (8).
Shaving is an excisional technique which allows the endometriosis nodule to be removed without opening the digestive tract lumen.
The approaches, advantages and risks of each technique are presented in an academic manner in the video below.
The major advantage of this technique concerns avoidance of contamination of the abdominal cavity from bacteria contained in the colon and considerable reduction in risk of certain adverse complications of this surgery (risk of digestive fistula is reduced by 5-6 x, hemorrhages occurring at digestive sutures are completely avoided). The improvement of postoperative symptoms is significant, as shown in clinical studies including patients operated on at Rouen University Hospital (4,5,9,10). On the other hand, exeresis of endometriosis nodules may be incomplete, with a risk of recurrence possibly higher than with other techniques in the long term. In our experience, we estimate a risk of recurrence of about 8% at 5-10 years after surgery (11). On the basis of these observations to avoid rectal recurrence in a single patient, 12 patients would have to undergo segmental colorectal resection instead of shaving, which would logically entail a higher risk of postoperative complications (12). These arguments for and against shaving should be discussed during the preoperative consultation. Most experts agree that shaving is the first choice, when nodule (small, shallow nodules) and patient characteristics (women over 30 years of age, who already have children and accept postoperative medical treatment, patients who refuse transfusions, etc.) allow it.
Discoid exeresis involves“cutting” the nodule and opening the digestive tract lumen, followed by repair of the tube with a transverse suture (perpendicular to the axis of the digestive tract).
This technique is used by certain teams worldwide and is an indicator of excellence for our team. The two founding surgeons of IFEM Endo have in total performed more than 450 discoid resections, placing them among the most experienced surgeons for this technique in the world. Our team has published a large number of scientific and teaching articles on discoid resection, which are regularly cited in international literature (4,13,14,15,16). The advantages of discoid resection over traditional segmental resection include better preservation of the rectum, in terms of length and volume, vascularization and nerves that control its function, as well as the absence of risk of colonic constriction after surgery. This may allow better functioning of the operated rectum in women having undergone discoid resection compared to those having undergone segmental colorectal resection, particularly when nodules affect the last 10 centimeters of the rectum (endometriosis of the lower or middle rectum). Compared with shaving, the advantage of discoid exeresis involves greater probability of complete exeresis of nodule edges, particularly that are deep and in contact with digestive tract lumen. However compared with shaving, discoid excision carries a notable risk of digestive fistula (1,17). Since cutting of the nodule creates an opening in the digestive tract, this opening requires a suture which may become loose in 1 to 3% of cases, leading to leaking of stool outside the colon and necessitating an emergency re-operation and creation of a stoma (artificial anus). The risk of fistula is comparable to that of segmental resection (which also involves suture of the colon), but is 5 to 6 times higher than that of shaving, which does not require suture. Recurrences in the rectum after discoid resection are very rare occuring in less than 2% of cases in our experience.
Segmental resection is a “traditional” technique for the treatment of all kinds of colonic lesions (endometriosis, infectious lesions, cancer) and allows a whole segment of colon to be removed and healthy margins of various width around the lesion.
This requires connection of the proximal and distal ends of the removed segment, with a circular suture. Segmental resection is a technique performed regularly by digestive surgeons, even by those with no particular experience in endometriosis, as it is used for other pathologies of the digestive tract. The advantage of this technique is linked to the more radical nature of the exeresis with wide healthy margins, as for cancer treatment, which allows a very low risk of recurrence (around 1%) in the rectum (18). Also, segmental resection allows removal of all sized nodules and particularly very large nodules for which shaving and discoid resection are technically impossible. On the other hand, risk of immediate complications after segmental resection is higher compared to shaving and discoid resection (12). There is also probably a higher risk of dysfunction of the operated rectum when the nodule involves the lower or middle rectum (the last 10 cm of the rectum) (19). This dysfunction leads to a syndrome known as LARS (low anterior resection syndrome) which associates difficulties in eliminating stools, very frequent stools, difficulties in retaining stools and even anal incontinence (20,21). Postoperative functional problems after segmental resection can sometimes be very problematic and has led us to innovate in surgery for nodules of the lower rectum, by proposing innovative techniques for discoid exeresis of very large nodules, such as the “Rouen technique” (22) and “double discoid” exeresis (14).
The use of one of the three techniques is chosen before surgery, according to the characteristics of digestive endometriosis nodules and needs of the patient. Our surgeons calculate the best benefit/risk balance in each case, but the final decision is made by the patient.
An equal use of the 3 techniques reflects the absence of preference on the part of our surgeons, the individualized and tailored choice of each type of surgery and the aim of ensuring the best result for each case (8).
Before performing surgery for digestive endometriosis, the surgeons require information on the number and location of the different lesions, obtained from preoperative imaging, including MRI, endopelvic ultrasound, endorectal ultrasound, colonography depending on the case. These tests will be recommended according to your disease type.
Colorectal endometriosis surgery is generally complex, and patients should be made aware of the rate of complications before agreeing to the procedure. The following list of complications is not exhaustive, and concerns only those of frequency greater than 1%. Depending on your particular situation, the risk of certain complications may vary and will be discussed in detail before surgery.
Our surgeons put their considerable experience in this type of surgery (8,23) to avoiding these complications as much as possible, by choosing the surgical strategy best suited to your situation, identifying the first signs of a complication and by rapid intervention for resolution of a complication if required.
Intraoperative risks (during surgery) with a cumulative under 1% :
Immediate postoperative risks (during the first 2 weeks after surgery)
Late postoperative risks(more than one or two months postoperatively) :
When performing surgery for digestive tract endometriosis, it is necessary to take into consideration the possibility of placing a temporary stoma (artificial anus).
The purpose of a stoma is to divert stool upstream from the surgical site to allow for better healing. The stoma can be performed at the outset, during endometriosis surgery, when the surgeons (gynecologist and digestive surgeon) estimate that there is a significant risk of incomplete healing of the digestive suture, which can lead to digestive fistula. Digestive fistula is one of the most severe complications of digestive surgery (17) and is due to the opening of digestive suture, with release of stool into the abdomen (leading to peritonitis) or into the vagina (when an excision of the vagina has been performed). When a stoma is not performed immediately, the occurrence of a fistula requires emergency surgery and placement of a temporary stoma. The stoma is maintained for about 2 months. Its closure by a new surgical intervention is performed once complete healing of the digestive tract suture is certain. In the case of digestive fistula, the stoma may be maintained for several months until complete healing of the fistula (17). One or more additional surgeries may also be required to achieve permanent closure of the fistula (17).
Placing a stoma does not prevent all risks of digestive fistula, but reduces the risk of complications following the appearance of the fistula (peritonitis, complete opening of the digestive suture, etc). Performing a stoma however, presents risks of its own. These specific complications require surgical repair in about 8% of cases (24).
Consequently whether a stoma should be perfomed or not requires detailed discussion with the gynecologic and digestive surgeon before surgery, so as to find the best balance between expected risks and benefits.
In the absence of surgical treatment for your disease, the disease development, even minimal and despite medical treatment may lead to the following symptoms:
Surgery for digestive endometriosis cannot be envisaged without considering remote consequences on digestive function. Generally, we do not propose surgery to patients with no symptoms, for the simple reason that the surgery may engender the appearance of certain disorders. Even if minimal, these disturbances are unacceptable in patients with normal digestive function before surgery. The preoperative consultation allows a thorough discussion of risks related to surgery in the light of possible complications related to the evolution of digestive endometriosis without surgery. This enables patients to make an informed decision.
1 200
women treated each year in France for digestive endometriosis
50%
experience an improvement in their digestive symptoms with medical treatment
2%
have a risk of recurrence 5 years after colorectal resection or discoid removal
Bibliography
Our team has a strong track record in digestive endometriosis surgery. More than 300 patients received surgery for digestive endometriosis in 2019 in our center, one of the most experienced in Europe and across the world (8).
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