Endometriosis (hereinafter referred to as endometriosis) is a common gynecological disease, mostly in women of childbearing age, and its incidence has been increasing year by year recently. It is believed that endometriosis can be divided into three types: peritoneal, ovarian chocolate cysts and deep infiltrative endometriosis (DIE). Many scholars believe that these three types of endometriosis are different pathophysiologic processes.
I. Definition
Deeply infiltrating endometriosis (DIE) is a condition in which a functional endometrial growth invades deep into the peritoneum and pelvic organs to a depth of more than 5 mm and is referred to as DIE. The anterior border is from the upper 1/3 of the vagina to the posterior cervical region and even the posterior and inferior isthmus. Therefore, DIE is in a sense a posterior cervical endometriosis. In some patients, the lesion is located in the anterior pelvis and mainly invades the bladder wall.
II. Classification
There is no uniform classification of DIE, and all classification methods have certain shortcomings. Two classification methods are described below.
1.Chapron’s 4-level typing of DIE lesion sites
Anterior pelvic type
Bladder DIE
Posterior pelvic type
Uterosacral ligament DIE
Vaginal DIE
Intestinal DIE
Single lesion type DIE
u lesion not involving the vagina
u lesion involving the vagina
Multiple lesions DIE
2. Donnez et al.’s 3-type classification,
Type I is a lesion in the vaginal rectal septum: 10% of cases, usually small (about 2 cm), easy to diagnose, preoperative IVP is not necessary, vaginal approach is sufficient; Type II is a lesion in the posterior vaginal fornix: most common, 65% of cases, barium enema is often normal; Type III is an hourglass shaped lesion: 10% of cases, 78% of cases have rectal wall infiltration, preoperative barium enema and bowel preparation are necessary, IVP is also required for larger lesions. IVP is also required for larger lesions.
III. Pathogenesis
There are two explanations for the occurrence of DIE: the theory of transmural reflux and the theory of chemotaxis. Most scholars now believe that DIE is caused by reflux of menstrual blood in women, which causes endometrial glandular epithelial and mesenchymal cells to implant in the pelvic peritoneum, and endometrial cells with different qualities to reflux into the pelvic cavity and adhere to the peritoneal surface. connective tissue or smooth muscle tissue to proliferate together to form nodules. The latter refers to the cells on the peritoneum or the remnants of Mullerian ducts to endometrium cells to metastasize and form DIE.
1.Clinical manifestations
Clinical manifestations are closely related to the site of the lesion. Patients with vaginal rectal diaphragm and endometriosis of the uterosacral ligament often complain of pain in the lower abdomen and lumbosacral region during menstruation, which is persistent and sometimes intensifies, with the most intense pain before and at the beginning of menstruation and relieved after menstruation clears. Deep intercourse pain is a common symptom in these patients. Some patients may have increased menstrual flow and prolonged periods, manifested as spotting bleeding before and after menstruation. Tender nodules may be seen in the rectal recess of the uterus and the uterosacral ligament on gynecological examination. The ectopic endometrium invades the intestinal wall and forms a mass, which compresses the rectum and produces a sensation of urgency and heaviness, which may lead to pelvic pain, rectal pain, periodic rectal bleeding, diarrhea, constipation and painful intercourse. During rectal examination, extra-intestinal wall masses or extra-mucosal masses can be palpated, with obvious tenderness and smooth and intact mucosa. Endo-urethral syndrome may invade the entire bladder and ureter, and also the kidneys. Symptoms mostly present as urinary tract irritation related to the menstrual cycle, such as frequency, urgency and difficulty in urination. If the kidney is involved, the symptoms are most insidious, mainly menstrual back pain and hematuria; if the ureter is involved, the symptoms are mostly menstrual renal dysfunction, lumbar and abdominal pain and hematuria, with hypertension suggesting the presence of upper urinary tract obstruction; if the bladder is involved, the main manifestations are urinary frequency, bladder pain, urinary pain and hematuria, which are obvious or aggravated during menstruation, but it can also be manifested only as discomfort in the vaginal area of the bladder or menstrual discomfort.
2.The anatomical distribution of DIE and its relationship with pain
DIE can be located in the uterine trap of the bladder, rectal trap and pelvic lateral wall, but mainly in the rectal trap such as the uterosacral ligament, uterine rectal fossa, vaginal rectal septum, vaginal vault, rectum or colonic wall. Therefore, the term DIE is generally used to refer to endometriosis lesions in the rectal recesses of the uterus. The extent of pelvic adhesions is also an important factor in causing painful symptoms.The close association of DIE with clinical pain symptoms may be due to the following reasons: (1) Deeply infiltrating nodules, (1) Deeply infiltrated nodules, which increase in size during menstruation or under the external force of sexual intercourse, compress the sensory nerves located in the area and cause pain. (2) Increased distribution of nerve fibers in DIE lesions compared to surrounding tissues, with significant infiltration of stromal cells, nerve bundle membranes, and nerve endothelium. (3) The endoneurial lesion causes local inflammatory reaction as well as increased pain-causing factors in the process of infiltrative growth to the deeper part of the lesion.
3. Diagnosis of DIE
It is very important to identify the site of DIE before surgery, because the treatment effect is obviously related to the thoroughness of surgical excision. The appropriate information can be obtained by asking for symptoms, gynecological examination and preoperative auxiliary tests.
Pain and infertility are the main symptoms of DIE. Clinical manifestations such as dysmenorrhea, deep intercourse pain, non-cyclic lower abdominal pain and intestinal and urinary tract symptoms are closely related to the site of the lesion. The site of the corresponding lesion can be understood by careful questioning of the symptom presentation. The relationship between the pain symptoms and the menstrual cycle, whether they worsen during menstruation, and whether the use of drugs that inhibit ovarian function can reduce the pain symptoms should be understood.
Gynecologic examination: purple-orange nodules seen in the posterior fornix during speculum examination are typical of DIE, however, in some patients the lesions are not typical and may be seen as pale red, lesions prone to contact bleeding, or thickened and stiff mucosa in the posterior fornix area. Sometimes the posterior fornix mucosa may even appear to be perfectly normal in presentation. Painful nodules may be palpable on transvaginal bimanual examination, but in some patients no nodules are present and only asymmetric thickening, stiffening and tenderness of the uterosacral ligaments may be felt. The presence of a nodular lesion can be more clearly felt on triple examination if necessary. In more than 85% of patients with DIE, the vaginal mucosa is not visibly diseased, and nodules are palpable in about 87% of patients during the duplex examination. Therefore, the presence of DIE cannot be excluded even if all gynecologic examinations are normal.
Ancillary examinations.
Transrectal ultrasonography
The advantage of transrectal ultrasonography is that it can detect the invasion of the rectal wall by DIE. Preoperative knowledge of the invasion of the rectal wall is very important in deciding the surgical approach. (1) Symptoms of rectal irritation during menstruation. (2) Rectal bleeding during menstruation. (3) Clinical examination suspects invasion of the rectal wall. (4) The lesion is more than 3 cm in diameter. If an invasion of the rectal wall is suspected, adequate bowel preparation should be made before surgery.
MRI examination
The advantage of MRI is that the entire pelvic organs, either anterior or posterior pelvis, can be examined simultaneously for two reasons: (1) DIE is mainly located behind the uterus, where transvaginal ultrasound cannot be well examined. (2) MRI is superior to transvaginal ultrasound for the diagnosis of DIE if it is located in the bladder. Although MRI is more sensitive for the diagnosis of the uterosacral ligament, it is relatively less sensitive for determining the degree of bowel invasion.
Cystoscopy.
If endometriosis of the bladder is suspected, cystoscopy should be performed; however, if the cystoscopy is unremarkable, the presence of endometriosis of the bladder cannot be ruled out. Cystoscopy can also determine the relationship of the lesion to the ureteral bladder opening in order to determine the surgical approach.
Serum CA125 measurement has some reference significance in the diagnosis of DIE, especially in those with elevated preoperative serum CA125. Follow-up changes in serum CA125 can be an indicator to determine the efficacy of surgery and predict recurrence.
For patients with parametrial infiltration, ultrasonography of both kidneys should be performed to exclude pelvic ureteral effusion, and if necessary, intravenous pyelogram (IVP) should be performed to clarify the site of obstruction and renal hemogram to estimate the impaired renal function.
Treatment
Drug therapy: There are no special drugs for deep infiltrative lesions, and the principles of drug therapy and the types of drugs are the same as those for other types of endoleptic disease. The purpose of drug treatment is to relieve the disease or as an adjuvant treatment before and after surgery. Medication can reduce the size of the lesion and relieve the pain, but the disease often recurs after stopping medication. Commonly used medications include high potency progestin, danazol, endometrium, gonadotropin-releasing hormone analog (GnRH-α), danazol vaginal ring, and levonorgestrel intrauterine release system (Mannorrhea).
Medication may be considered in the following cases: (1) Recurrence of symptoms after several previous surgical treatments. (2) Surgery needs to be postponed for various reasons. (3) If the lesion is widespread and surgical excision is difficult and the risk of surgery is high, preoperative medication can be considered to make the lesion shrink and thus reduce surgical bleeding and make the surgery safer and more effective, but preoperative medication itself cannot improve the prognosis of surgery. Postoperative medication can delay recurrence.
2.Surgical treatment: Deep infiltration endoheterotrophy emphasizes surgical treatment more than other types of endoheterotrophy. The purpose of surgery is to remove ectopic nodes, separate adhesions, relieve pain and restore normal anatomical relationship and physiological function of pelvic organs, so as to facilitate the restoration of fertility and delay recurrence.
The choice between trans-laparoscopic or open surgery has been controversial. The choice of surgical approach depends not only on the staging of the patient’s lesion but also on the experience and skill of the operator. There is no clear evidence on the effect of different surgical approaches on reproductive function. For pain control, both laparoscopic and open lesion excision have shown significant therapeutic results after surgery. The time to recurrence of endometriosis after surgery is also approximately the same for both modalities, with a recurrence rate of 19% after 5 years for both.
However, laparoscopy offers the following advantages. With the magnification of the laparoscope, the surgical field of view is clearer and it is easier to observe the ectopic foci in specific areas such as the rectovaginal septum; in addition, the postoperative pain is less, the hospital stay is shorter, and the postoperative adhesions are mild. Laparoscopy is easier to enter the retroperitoneal space and has a magnifying effect, which is advantageous for identifying lesions. Laparoscopic surgery is performed in a cystotomy position, which facilitates operation in the perineum, exposing the posterior uterine anatomy during surgery and placing vaginal and rectal probes to identify the corresponding anatomical structures.
Complete removal of the DIE lesion in a single operation is essential for a good outcome, and the distribution of the DIE lesion determines the approach and extent of the operation. Partial cystectomy is used to treat endometriosis of the bladder. Although this procedure can be done laparoscopically, open surgery is preferred if the lesion is located at the ureteral opening and intraoperative ureteral bladder implantation is required.
When the lesion is located in the uterosacral ligament, laparoscopic surgery to remove the lesion is very effective. To avoid damage to the ureter, the ureter should first be detached during resection of the lesion. A transcystoscopic placement of a ureteral catheter helps to separate the ureter and avoid injury. If the lesion is large, it is sometimes necessary to separate the lateral rectal fossa. If the lesion involves the uterosacral ligament bilaterally, both ligaments should be removed; conversely, if the lesion involves only one side of the uterosacral ligament, lateral resection of the affected side is sufficient. In this case, the lesion often does not involve the vaginal wall, so it is not necessary to remove part of the vaginal wall.
If the lesion involves the vaginal wall, the lesion can be removed laparoscopically or transvaginally. In this case, the pararectal space is first separated, the rectal wall is freed from the vaginal wall, and then the lesion is removed from the vaginal wall.
The management of intestinal endometriosis depends critically on whether it is a lesion that invades the muscular layer of the intestinal wall. If the lesion is located only on the plasma surface of the intestine and does not involve the muscular layer, no bowel surgery is required.
In the case of intestinal endometriosis, the decision on the surgical approach and modality should be based on the patient’s age, whether pregnancy is desired, past surgeries, and the characteristics of the intestinal DIE (location, number, size and extent of the invasion of the intestinal wall, length from the anus, presence of concomitant DIE in other areas), the degree and extent of pelvic adhesions, and the experience of the surgeon. Both open and laparoscopic surgery can be used for the treatment of intestinal endometriosis.
With regard to intestinal DIE, the main surgical modalities are as follows.
Laparoscopic excision of superficial intestinal lesions
Superficial endometriosis lesions located on the surface of the intestinal plasma membrane can be removed with scissors; care must be taken if separation is done with electrocoagulation, which can cause thermal injury and lead to delayed intestinal perforation. After lesion removal, the wounds on the dump surface can be intermittently sutured.
Laparoscopic total intestinal wall disc excision
For patients with lesions invading the entire intestinal wall, total disc resection of the intestinal wall can be performed. The intestinal wall is incised longitudinally along the lesion but can be sutured transversely to avoid narrowing of the intestinal lumen. The intestinal mucosa can be closed with continuous sutures of 3/0 vicryl, and the pulpy muscle layer can be closed with two interrupted layers of silk sutures.
Partial bowel resection (via laparoscopy or open surgery)
Partial bowel resection can be accomplished laparoscopically or by open surgery, simply by removing the endometriosis lesion from the intestinal wall. Partial bowel resection is mainly indicated for single lesions larger than 3 cm, single lesions invading more than 50% of the muscular layer of the intestinal wall, or more than 3 lesions invading the muscular layer of the intestinal wall. It is necessary to separate the pararectal space and free the rectum without separating the lesion from the intestinal wall. It is best to separate the fibrofatty tissue close to the rectal wall, and the mesenteric separation should not be too far away, 2 cm from the lesion. The distal end of the intestinal canal is removed with a linear cutting anastomosis, and the proximal end is removed from the abdominal cavity by a small incision on the pubic union, and then the lesion is removed, and then the two severed ends of the intestinal canal are anastomosed with an intestinal canal anastomosis with an intestinal canal anastomosis, and the anastomosis can be checked for leaky holes after filling the pelvis with water and injecting gas through the anus.
Surgical complications
Ureteral injury and anastomotic fistula are two common complications. Freeing the ureter at the beginning of the procedure reduces the occurrence of ureteral injury. Other complications are temporary irritable bowel sign, perineal abscess and rectovaginal fistula formation. In cases of extensive lesions involving the uterosacral ligament, the nerves innervating the bladder may also be damaged, causing postoperative urinary difficulties and urinary retention. Gastrointestinal complications include constipation, difficult defecation, and diarrhea.