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Endometriosis - the praying mantis within the pelvis

Marc Possover,
Juli 13, 2024

A story of love and hatred between endometriosis and the pelvic nerves

Endometriosis is a disease that has been known for several centuries but has only recently gained widespread recognition - thanks in large part to social media platforms and the insights of the patients themselves. However, endometriosis is still too often categorized on the extremes of the scale: on the one hand trivialized as a harmless disease "that only hurts during menstruation”, the fate of women since time began, or on the other extreme, dramatized to the point where recommending assisted fertilization as the only option of becoming pregnant. Endometriosis has many more aspects than this and is generally classified into three categories: endometriosis, which spreads into the wall of the uterus itself (adenomyosis), endometriosis, which spreads into the lower abdomen (endometriosis genitalis externa), and the so-called deep endometriosis, which behaves like a benign tumor. The latter develops around the uterine cervix and will sooner or later invade the neighboring organs through its growth, namely the bladder in front, the rectum in back, the ureters and the pelvic nerves to the sides. This last form of endometriosis behaves like a praying mantis in the pelvis. It needs the tissues to live and grow, but in its evolution it destroys them in turn as a sign of its gratitude. That this form of endometriosis has an affinity for pelvic nerves is a well-known phenomenon and this explains both why this disease is so painful and the multitude of associated symptoms. Thus endometriosis can reach the nerves located in the center of the small pelvis - the so-called vegetative nerves of the pelvis - as well as the large nerves located in the lateral wall of the pelvis - the so called somatic nerves.

Deep infiltrating endometriosis is not, as is often said, a chameleon, which takes on different forms and aspects. No! Endometriosis is a praying mantis that does not hide itself, but which, depending on where it attacks, will produce different clinical signs, while the disease will remain the same. Its best weapon is that it is still too often underestimated and too long left alone to grow undetected.

1. Endometriosis of the vegetative nerves of the pelvis

Vegetative nerves, or "autonomic nerves" as their name suggests, are autonomous, doing their work without the need for the person's voluntary and cognitive thinking.

The distribution of this autonomous nervous system is present in most of the organs and glands of the organism whose automatic and involuntary functions it controls, hence the name of the vegetative nervous system. When its action is interrupted or disrupted in some way - as when endometriosis is present, the organs continue to function but in a disorganized way. It ensures the normal functioning of vegetative functions (breathing, heart rate, blood pressure, digestion, secretions, body temperature, water balance, etc.) and instantly responds to all physical and emotional demands. It is a system for adapting the body to its environment.

At the level of the small pelvis, they form a meshwork of very small nerves - the "pelvic plexus" - which is located in the suspensory ligaments of the uterus, at the crossroads between the bladder, genitals and rectum - in women, the so-called "sacro-uterine ligaments". Thus any endometriosis of the pelvis affecting the uterus (adenomyosis), ovaries, pelvic peritoneum (endometriosis genitalis externa) as well as endometriosis of the suspensory ligaments of the uterus is likely to induce such visceral pains and vegetative symptoms. In other words, endometriosis almost always induces such visceral pain by almost systematic damage to the pelvic vegetative nerves. These tiny nerves transmit vital information to the pelvic organs responsible for performing urination, defecation, sexual activity and continence functions, but also receive information from these same organs to transmit to the brain. Thus the irritation or inflammation of these nerves behaves like a bushfire and affects all these functions simultaneously. This multitude of signs and symptoms in the absence of a pathology of these same organs can confuse many medical professionals and as a result these symptoms are all to often still labeled as psychosomatic or even purely psychic.

1.1 Digestive, urinary and sexual disorders

Patients with endometriosis will have such an activation of these vegetative nerves due to inflammation of the uterus - especially during menstruation - and/or due to direct damage to these nerves (endometriosis of the sacro uterine ligaments).

In fact, any endometriosis of the pelvis affecting the uterus (adenomyosis), ovaries, pelvic peritoneum (endometriosis genitalis externa) as well as endometriosis of the suspensory ligaments of the uterus is likely to induce such visceral pain. In other words, endometriosis almost always induces such visceral pain by almost systematic involvement or even damage to the pelvic vegetative nerves.

This results in functional disorders such as:

  • Irritation of the bladder nerves with the feeling of having to urinate often, even if the bladder is not full, burning when emptying the bladder (such as a bladder infection), urgent feeling of having to go to the toilet...
  • Irritation of the nerves of the digestive tract with sudden urges to empty the bowel, pain during bowel movements and during menstruation an alternation of digestive disorders varying between constipation and diarrhea.
  • Lower abdominal pain and very often pain during sexual activity (sometimes constant, sometimes dependent on the position).

Nevertheless, with the progression of the disease, endometriosis will not only irritate the nerves: endometriosis is like a praying mantis that, over time, will destroy the same nerves that have shown it the way to grow. Thus, patients will no longer experience an activation of the functions of the bladder but will experience the opposite, over time they will loose the sensation of having to go to the toilet; without really realizing it, they’ll start emptying the bladder using abdominal press (necessary to control post-void residual volume by sonography 1s/year). Similarly, constipation will become more problematic than episodes of diarrhea during menstruations. In addition to the vaginal pain that limits their sexual activity, they will feel less and less desire for sexual relations, with all that this brings with it in frustration for her and for the partnership.

1.2 Low abdominal/pelvic pain with irradiation in the lower back

In the same way, these patients will present with lower abdominal/pelvic pain called "visceral" pain. This pain is described as non-localized but a highly intense pain, spread throughout the whole pelvis, ventrally more left than right (because of the recto-sigmoid that is descending to the pelvic cavity at the left side), but without very precise localization.

Since these nerves rise along the back towards the spinal cord and brain, pelvic pain almost always radiates upwards into the lower back.

This pain should not be trivialized and requires an ultrasound of the kidneys to exclude ureter endometriosis with dilated kidneys, also responsible for back pain.

In the same way this pain will reach the solar plexus and will influence the whole sympathetic system of the body, which explains functional and painful disorders in other parts of the human body at quite a distance away from the small pelvis.

1.3 Multiple vegetative disorders

As mentioned, an attack on the vegetative nerves will spread like a wild fire to the entire vegetative system of the whole body and will induce a host of symptoms and clinical signs that are easy to recognize for those who seek them and want to see them:

  • Saliva production in the mouth is reduced, resulting in dry mouth and lips (often with chapped lips)
  • Dilation of the pupils
  • Palpitations, accelerated cardiac activity (tachycardia)
  • A pale face, often with red-patches of stress on the neckline at the same time.
  • Increased sweating in the armpits and the hands
  • Significant fatigue, lack of energy, desire to do nothing
  • Episodes of anxiety, depression, or both
  • Mood swings from one moment to the next, with more aggressiveness during menstruation
  • Nausea or even vomiting, loss of appetite
  • Episodes of syncopation, dizziness or even loss of consciousness (it's not dramatization!).
  • Diaphragm spasms with chest pain radiating into the shoulders or arms (not just right as in diaphragm endometriosis, but also left side), with difficulty for breathing
  • Abdominal bloating with more constipation outside menstruation
  • Stomach pain with burping
  • Disorders of the immune system with tendency to "be sick more often".

Sympathetic hyperactivity is also associated with several components of the metabolic syndrome such as abdominal obesity (although it is currently unknown whether sympathetic imbalance is a cause or consequence of obesity), arterial hypertension, hyper-insulinemia, hyperlipidemia, type 2 diabetes, sleep apnea or sedentariness. There is therefore a strong interaction between the autonomic nervous system and the endocrine system.

Obviously all these signs can vary from one patient to the next but also in the same patient, from one day to the next, depending on her physical and psychological condition. In general, the symptoms are much more pronounced during menstruation, but any other stressful situation - also a psychological one – can activate the vegetative system and in turn trigger the symptoms. Similarly, disorders of the digestive tract or bladder will lead to the activation of this pelvic plexus with the same consequences: indeed, the nerves do not ask themselves the question "what irritates them”, but simply wait for any reason, even the most innocuous, to activate themselves.

Thus, patients with endometriosis are too often and unfairly labeled as unstable or even psychotic. Of course, severe recurrent pain, problems of social isolation, vegetative disorders, all these problems can obviously affect a person so that over time they can indeed develop psychological disorders. It should be known however, that these same disorders represent an integral part of the disease of "endometriosis". These disorders are a consequence and not the reason, and certainly not a reason for these women not to be taken seriously.

It is hugely important as a doctor to recognize all of these signs, to research them prior to starting the conversation with your patient, to literally read these vegetative signs. The face is the best mirror and will tell you what you need to know.

2. Endometriosis of the somatic pelvic nerves

Somatic nerves control the red muscles of the human body and can thus be directed or at least influenced by our thoughts. They usually innervate the so-called "skeletal muscles" that allows us to perform our muscular activities such as walking, but also some more subtile pelvic functions such as erection, or part of the continence of the bladder and rectum. These somatic nerves emerge from the spinal cord and continue deep into the pelvis forming the sacral plexus, from which the sciatic nerve (the largest single nerve of the entire body), the femoral nerve, the pudendal and the obturator nerve all emerge. While the sciatic nerve reaches the leg by passing deep into the small pelvis, the femoral nerve reaches the leg by passing through the fold of the groin. The gluteal nerves emerge from the sciatic nerve and reach to the buttocks.

As in vegetative nerves, somatic nerves have the function of carrying diverse information to and from the brain.

  1. Information to the brain – neuropathic pain

Nerves carry information and messages from the periphery to the brain, among other things, the sensation of pain. The irritation of these nerve fibers induces an extremely sharp pain called "neuropathic" pain, with a type of burning (allodynia) or electrical shooting pulses. It is, in any case, very intense and located at the level of the skin. These pain sensations are described as very precise, very or at least relatively well localized at the level of the skin, in the lower half of the body. The location and course of this pain can be described very precisely and is generally not accompanied by vegetative signs (except perhaps nausea due to the use of pain medication).

Somatic nerves can be compared to electrical cables: just as each electrical cable corresponds to a bulb, so each nerve corresponds to its own specific and precise area of the skin (called dermatomes). Thus, precisely where neuropathic pain is described on the body, informs about which nerve(s) is(are) responsible for transporting pain to the brain, without revealing at what level between the skin and the brain, this pain is generated. Thus, pain reported:

  • at the level of the lower back, buttocks and back of the legs down to the soles of the feet corresponds to the sciatic nerve
  • on the inside of the thigh down to the knee (not below) corresponds to the obturator nerve or genito-femoral nerve
  • at the genito-anal areas corresponds to the pudendal nerve
  • at the level of the anterior surface of the thigh, corresponds to the femoral nerve

may correspond to an affection of the pelvic somatic nerves.

Depending on the nerve(s) affected, the patient will be labeled with various diagnoses such as vulvodynia, sciatica, coccynia, chronic pelvic pain, chronic back pain and other syndromes, whereas the cause in all these different pain diagnoses is the same - deep endometriosis. Typical for these neuropathic pain sensations are their intensity, they are excruciating often with radiating pain that descends to the genito-anal areas or in to the legs.

At the onset of the disease, the pain appears exclusively during menstruation, but over time - and this usually does not take a matter of years – the pain will manifest on a constant daily basis. It is ever-present all the time, can increase from one day to the next, from one hour to the next, from one second to to the next. They are very difficult to control by drugs and require the use of morphine-based treatments sooner or later. These pains take such a place in the patient' s life that she no longer has a professional, social or even family life. Then this woman's life should flourish, she fades away. Endometriosis destroys physically and psychologically the women who gave her life, what she needs to develop and grow - she is a most ungrateful praying mantis.

  1. Information from the brain to the skeletal muscles – motor dysfunctions

Endometriosis induces irritation of the pelvic nerves, which as described above induces neuropathic pain. The motor fibers that carry the brain's orders to the periphery are larger than the fibers that carry pain information to the brain. These motor fibers are more resistant so that motor disorders only appear in advanced forms of the disease. Nevertheless, when the disease has reached this stage, it suffocates, infiltrates, destroy the nerves that gave it life - it is like a terrible praying mantis. Endometriosis of most pelvic nerves will sooner or later attack and destroys them. If it is not treated in time, the pain worsens as the disease progresses, leading to neurological disorders and in the end, to loss of function, which ultimately is irreversible.

Thus typical symptoms at an advanced stage:

when the sciatic nerve is involved:

  • Feelings of numbness in the lower back, the buttocks and back of the legs, mostly on the sole of the foot or the outer edge of the foot or the rear side of the legs.
  • Loss of strength or restriction of movement of the ankle, flexion of the sole and back of the foot is limited.
  • Climbing stairs becomes increasingly difficult and impossible over time.
  • The Achille’s reflex is reduced or no longer present.

when the pudendal nerve is involved:

  • Feelings of numbness in the genito-anal areas
  • Loss of turgescence of the clitoris
  • Continence disorders are extremely rare, because for this, the lesion must be bilateral, a situation which fortunately, is quite rare

when the obturator nerve is involved:

  • Main presenting complaints include numbness in the medial thigh, groin or pubic bone
  • Weakness and a feeling of leg instability
  • Examination findings may reveal a circumducting gait secondary to an externally rotated hip, weakness or wasting of the adductor muscles and a decrease in hip adduction and internal rotation of the hip

when the femoral nerve is involved:

  • There may be instability of the knee (often described as 'buckling') on climbing stairs.
  • Weakness or even loss of knee jerk
  • Numbness of the ventral/medial side of the leg and calf may occur.
  • Examination findings may reveal a quadriceps muscle weakness and wasting, with reduction or loss of “patellar reflex”

3. Diagnosis of endometriosis of the somatic pelvic nerves

Endometriosis of the pelvic nerves is therefore a very particular form of endometriosis which is still little-known, even among physicians. Yet, there is good news for the women affected: endometriosis of the pelvic nerves can now be diagnosed and treated thanks to new scientific findings and modern procedures. Although the disease is rare, it occurs more frequently than was previously assumed. The reason: most women affected by the disease tend to consult a neurologist, a back specialist (neurosurgeon, orthopaedic surgeon) or a pain therapist because the typical symptoms mentioned above do not show the character of gynaecological pain. Gynaecologists who are not familiar with endometriosis of the pelvic nerves will often refer patients with such symptoms to a specialist.

Diagnosis becomes more difficult when there is a combination of pain symptoms. So, for example, pain in the territory of the sciatic nerve + territory of the pudendal nerve, corresponds to a problem in the sacral plexus (= sacral radiculopathy), i. e. the origin nerves of the sciatic and pudendal nerves.

This diagnostic step of determining which nerve(s) is(are) involved in the creation and transportation of this neuropathic pain is essential. The type of treatment but above all the quality of the treatment depends directly on this diagnostic step. Because this requires in-depth knowledge of anatomy of the pelvic nerves, of their functions, as well as the specialized examination techniques and finally of the therapeutic treatment options, it is essential to consult a "neuropelveologist" to make a proper diagnosis where endometriosis of the pelvic somatic nerves is suspected. The gynecologist has access to these nerves for both examination and treatment, but lack the necessary knowledge in neurology for dealing with pathologies of the pelvic somatic nerves. Conversely, the neurologist understands the pathology of the nerves well but does not have access to these nerves that are located deep within the pelvis, either for the diagnostic stage or for the treatment of the pathologies of these nerves.

The neuropelveological examination is performed by a neuropelveologist: the pelvic nerves are scanned in the vaginal or rectal way and examined with the aid of ultrasound. A neuro MRT can also be used for diagnosis. If the suspicion is confirmed, only a laparoscopy can provide certainty.

When I started in 2004 with laparoscopic surgery for infiltrating sciatic nerve endometriosis, the reaction of colleagues was unanimous: "Mr. Possover, you will only see such cases of endometriosis once or twice in your lifetime". With our current series of more than 300 cases of pelvic somatic nerve endometriosis treated over the past 15 years, we have been able to prove the opposite. In fact, the situation changed with the day I started talking about this pathology not at congresses on gynecology but rather at congresses on orthopaedics, neurology, neurosurgery or even psychology. It was during this journey that I felt my own isolation by speaking on this topic, but also the isolation of these lost patients affected by endometriosis of the pelvic somatic nerves, patients forgotten by medicine because of a lack of knowledge. Since then, the general awareness on this special pathology has grown considerably and it has become clear that in the face of any sciatica or other neuropathic pain in the lower half of the body, without explanation, in women of reproductive age, especially if it increases during menstruation, the possibility of endometriosis of the pelvic somatic nerves must be evocated. Of course, the diagnosis can only be confirmed by performing laparoscopy; however, the diagnosis of endometriosis of these nerves can also only be excluded by performing laparoscopy. M. Possover, June 2019

4. Treatment of endometriosis of the somatic pelvic nerves

During a laparoscopy, a tiny camera is inserted through a small incision that reveals the fine structures of the pelvic nerves and their damage. If the diagnosis is confirmed during this examination, the treatment can be carried out during the same procedure. With the finest surgical instruments, the nerve is freed from the settled tissue. Depending on the stage of the disease, the function of the nerve can be maintained or restored.

  • Surgery only by an experienced neuropelveologist!

Treating endometriosis of the pelvic somatic nerves hormonally or simply with painkillers and taking a “wait and see” approach is not successful! Because this form of deeply infiltrating endometriosis cannot be stopped by hormonal treatment, NOT ANY SINGLE ONE !

Endometriosis of the somatic pelvic nerves cannot be compared with intestinal or bladder endometriosis: it is important to preserve every millimeter of the nerves, because even the slightest damage or need for resection leads to neurological deficits and irreversible nerve damage.

When the disease is diagnosed or even only suspected, the operation must be performed as early as possible. Due to the deep location of the pelvic nerves, this procedure poses a great challenge for the surgeon because the pelvic nerves lie behind numerous pelvic blood vessels - a highly sensitive region of the body that requires maximum surgical care, skill and experience. Patients diagnosed with endometriosis of the pelvic somatic nerves should therefore confide in the experienced hands of a specialist, if possible a neuropelveologist.

  • Surgery only by laparoscopy

The only effective treatment is laparoscopic surgery. The surgeon must have the necessary skills and knowledge of the anatomy of the pelvic nerves and vessels. If the operation is incomplete, changes in the anatomical conditions, adhesions and scar tissue will make any further operation more difficult. The operation through the buttocks is not effective because the disease develops in the pelvis and grows along the nerve outside the pelvis to the buttocks and not vice versa.

It is simply not sufficient to be a specialist in deep endometriosis surgery to operate on pelvic nerve endometriosis. Open abdominal surgery of the pelvic somatic nerves is impossible due to the location of the nerves in the depths of the pelvis. The use of microscopes as used in microsurgery is unsuitable for pelvic nerve surgery. Thus this surgery is not only best done by laparoscopy, but requires laparoscopy, without which it is impossible to operate according to the rules of microsurgery. The surgeon must know not only the approach of these nerves by laparoscopy, but also must have an absolute knowledge of the blood vessels of the pelvis in order to avoid bleeding during the operation, as well as the principles of surgery of the nerves - neurosurgery. Certified neuropelveologists have this know-how and have undergone targeted training in pelvic nerves surgery.

Prof. Possover has specialized in the neuropelveological treatment of deep infiltrating endometriosis of the pelvic somatic nerves, especially the sciatic nerve, the most difficult nerve to be reached by laparoscopy. In a series of more than 259 laparoscopic surgeries, Prof. Possover has shown that laparoscopic surgery leads to significant pain reduction. If the continuity of the sciatic nerve is maintained, the nerve will recover and the healthy function of the legs can be restored.

Live images of a surgery: endometriosis of the sciatic nerve

  • Back to more quality of life

If you are affected by the symptoms described above and no cause has yet been found, do not be afraid to talk to your doctor about the possibility of endometriosis of the sciatic nerve - whether he/she is a gynaecologist, neurologist, neurosurgeon, orthopaedic surgeon or pain therapist. The earlier this disease is diagnosed, the better the chances of recovery. The operation must be performed as early as possible - before the functional disorders become irreversible.

Last but not least, you also contribute to strengthening the perception and awareness of this still little known, special disease worldwide. Spreading the knowledge will benefit many other patients.

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Marc Possover