Bladder endometriosis

　　To date, the etiology of bladder endometriosis has not been clearly established, but there are the following three theories.

　　One, Implantation Theory

　　As early as 1921, some people believed that the occurrence of pelvic endometriosis was caused by the implantation of endometrial fragments with menstrual blood refluxing through the fallopian tubes into the pelvis and implanting in the ovary or other pelvic sites. Clinically, menstrual blood can be found in the pelvis during laparotomy during the menstrual period, and endometrium can be found in the menstrual blood. The endometriosis of the abdominal wall scar after cesarean section is a good example of the implantation theory.

　　Two, Peritoneal Theory

　　Also known as the metaplasia theory, it believes that ovarian and pelvic endometriosis is derived from the metaplasia of the mesothelial cell layer of the peritoneum. The mesonephric duct is formed by the invagination and development of the primitive peritoneum, and it is derived from the germinal epithelium of the ovary, the pelvic peritoneum, and the closed peritoneal invagination, such as the peritoneal鞘状突 (inguinal canal), rectovaginal septum, umbilicus, etc., all of which are derived from the coelomic epithelium. Any tissue derived from the coelomic epithelium has the potential to differentiate into almost indistinguishable tissue from the endometrium. Therefore, the mesothelial cells of the peritoneum may be prone to metaplasia into ectopic endometrial lesions under the stimulation of factors such as mechanical (including tubal patency, retroverted uterus, cervical stenosis), inflammatory, and ectopic pregnancy. The germinal epithelium on the surface of the ovary, being of primitive coelomic epithelium, has a greater potential for differentiation. Under the influence of hormones and inflammation, it can differentiate into various tissues that can be formed during embryogenesis, including the endometrium. The ovary is the most easily affected site in the ectopic endometriosis, which can be easily explained by the metaplasia theory. The implantation theory cannot explain the occurrence of endometriosis beyond the pelvis.

　　Three, Immune Theory

　　In 1980, Weed et al. reported that there is infiltration of lymphocytes, plasma cells, macrophages containing hemosiderin deposition and varying degrees of fibrosis around the ectopic endometrial lesions. They believed that this was due to the ectopic endometrial lesions acting as foreign bodies, which activated the body's immune system. Since then, many scholars have explored the etiology and pathogenesis of endometriosis from the aspects of cell immunity and humoral immunity.

　　(I) Deficiency in cellular immune function 1. Deficiency in T lymphocyte function; 2. Deficiency in natural killer cells (natural killer cells, NK). NK cells are a group of heterogeneous and multifunctional immune cells, whose functional characteristics are that they can kill certain tumor cells or virus-infected cells without the presence of antibodies, without antigen sensitization, and play an important role in immune surveillance within the body.

　　(II) Deficiency in humoral immune function Theories related to the occurrence of endometriosis tissue include: ① The lymphatic dissemination theory. It is believed that the endometrium can disseminate through the lymphatic duct, and some people have found that the parauterine lymph nodes and iliac internal lymph nodes contain endometrial tissue. However, the weakness of this theory lies in the fact that endometrial tissue is rarely seen in the central part of regional lymph nodes, and the common occurrence sites do not conform to normal lymphatic drainage; ② The blood dissemination theory. According to literature reports, ectopic endometrium has been found in veins, pleura, liver parenchyma, kidneys, upper arms, lower limbs, and so on. Some scholars believe that the most likely scenario is that the endometrium disseminates to the above tissues and organs through blood flow, and has even caused experimental endometriosis in rabbit lungs. However, some people believe that although these conditions may be caused by blood dissemination, the factor of local metaplasia cannot be excluded, as the pleura also originates from the coelomic epithelium. During the embryonic period, when the germ buds and mesonephros are produced, there is a possibility of coelomic epithelium becoming ectopic among them, and the tissue can later metaplasize to form endometriosis in each part.

　　Regardless of the source of the ectopic endometrium, its growth is related to ovarian endocrine function. Clinical data can illustrate this, as most cases occur in women of childbearing age (over 80% of those aged 30 to 50), and often accompany ovarian dysfunction. After the ovaries are removed, the ectopic endometrium atrophies. The growth of ectopic endometrium mainly relies on estrogen, and the secretion of gestational progesterone is more abundant, which inhibits the ectopic endometrium. Long-term oral administration of synthetic progestins such as norethindrone can cause pseudopregnancy and also cause the atrophy of ectopic endometrium.

　　Pathological changes:

　　The intrinsic endometriosis involves the growth of the endometrium from the basal layer towards the myometrium, being confined to the uterus, hence also known as adenomyosis. The ectopic endometrium often disseminates throughout the entire uterine muscular wall, leading to a reactive hyperplasia of fibrous tissue and muscle fibers due to the invasion of the endometrium, causing the uterus to swell consistently, but rarely beyond the size of a full-term fetal head. Uneven or focal distribution is generally more common in the posterior wall, often causing irregular enlargement of the uterus, resembling a uterine fibroid. The cross-section of the hyperplastic myometrium also appears to have a whirlpool-like structure, but lacks the capsule-like tissue that is present in fibroids. The center of the lesion has a softened area, and occasionally, small cavities containing a small amount of old clotted blood can be seen scatteredly. The endometrial glands observed under the microscope are the same as those in the endometrium, surrounded by the endometrial stroma. The ectopic endometrium changes with the menstrual cycle, but the changes during the secretory phase are not significant, indicating that the ectopic endometrial glands are less affected by gestational hormones. When pregnant, the stromal cells of the ectopic endometrium can show a marked decidual transformation, as mentioned above.

　　The interstitial endometriosis is a special type of intrinsic endometriosis, which is less common, that is, the ectopic endometrium only has endometrial stromal tissue, or the extent and degree of development of the stromal tissue after the endometrium invades the muscular layer is far beyond the glandular component. Generally, the uterus is consistent in size, and the ectopic cells are scattered in the muscular layer or concentrated in a certain area, yellow in color, often with elastic rubber-like hardness, softer than myoma, and often visible as string-like worm-like protuberances in the section, which can be used to establish the diagnosis. The ectopic tissue can also develop into polypoid masses in the uterine cavity, multiple in nature, with a smooth surface, wide pedicle with a large area of direct contact with the uterine muscular wall, and can protrude from the uterine wall into the uterine cavity or along the uterine blood vessels into the broad ligament. The ones that protrude into the uterine cavity can cause menorrhagia or even post-menopausal bleeding; the ones that protrude into the broad ligament can be detected by gynecological bimanual examination. Interstitial endometriosis can have lung metastasis, and even after the uterus is removed for several years, it can still occur. Due to this characteristic, some people believe that interstitial endometriosis is a low-grade malignant sarcoma.

　　The ectopic endometriosis invades tissues or organs outside the uterus (including ectopic endometrium that invades the serous layer of the uterus from the pelvis), often involving multiple organs or tissues.

　　The ovary is the most common site for the occurrence of external endometriosis, accounting for 80%, followed by the peritoneum in the cul-de-sac of the uterus, including the uterosacral ligament, the anterior wall of the cul-de-sac of the uterus, which is equivalent to the posterior fornix of the vagina, and the posterior wall of the cervix, which is equivalent to the internal os of the cervix. Sometimes the ectopic endometrium invades the anterior rectal wall, causing the intestinal wall to form dense adhesions with the posterior wall of the uterus and the ovary, making it difficult to separate during surgery. External endometriosis can also invade the rectovaginal septum and form scattered black-purple small spots on the vaginal fornix mucosa, even forming cauliflower-like protuberances, resembling cancer, and only confirmed by biopsy as endometriosis. In addition, as mentioned earlier, the fallopian tubes, cervix, vulva, appendix, umbilicus, abdominal wall incision, hernia sac, bladder, lymph nodes, and even pleura and pericardium, upper limbs, thighs, and skin may all have ectopic endometrial growth.

　　The ectopic endometrium in the cul-de-sac of the uterus can also form purple-black hemorrhagic spots or small blood cysts on the peritoneum, embedded in severe fibrous tissue, and the typical endometrium can be seen under microscopic examination. The ectopic endometrial tissue in this area can also extend to the rectovaginal septum and the uterosacral ligament to form tender firm nodules. Or it may penetrate the vaginal fornix mucosa, forming bluish-purple papillary masses, with many small hemorrhagic spots appearing during the menstrual period. If the anterior rectal wall is involved, it may cause rectal pain during the menstrual period, and sometimes the endometrial lesions can extend around the rectum to form a narrow ring, which is extremely similar to cancer, with about 10% of intestinal invasion in endometriosis. Lesions often occur in the serous and muscular layers, rarely involving the mucosa and causing ulcers. Occasionally, due to the formation of a mass or fibrous stricture or adhesion in the intestinal wall, the intestine may become excessively curved, causing intestinal obstruction, and can also cause irritation symptoms, such as intermittent diarrhea, which is more severe during the menstrual period.

　　Bladder endometriosis is a rare form of endometriosis, where the ectopic endometrium involves the full thickness of the bladder detrusor muscle is called bladder endometriosis. Bladder endometriosis is mostly a single lesion, about 90% located on the posterior wall and top of the bladder, with a few located below the ureteral orifice. The lesions are nodular, mainly composed of fibrous tissue, smooth muscle tissue, and endometrial glands and stroma distributed in islands or chains. The complications of bladder endometriosis mainly include pain, infertility, ectopic pregnancy (ectopic pregnancy), menstrual disorders, and sexual pain, among others. The specific manifestations are as follows:

　　1. Pain: It is one of the most common symptoms, with the most obvious pain in the lower abdomen and lumbar sacral area, usually starting 1-2 days before the onset of menstruation, the most severe on the first day of menstruation, and gradually subsiding thereafter. However, as the disease progresses, menstrual abdominal pain becomes more obvious.

　　2. Infertility: Accounts for 40% to 50% of endometriosis, among which primary infertility accounts for 41.5 to 43.3%, and secondary infertility accounts for 46.6 to 47.3%. It refers to couples living together for more than 2 years without taking contraceptive measures and failing to conceive.

　　3. Ectopic pregnancy (ectopic pregnancy): Ectopic endometrium can cause pelvic adhesions and fallopian tube obstruction, causing the fertilized egg to implant and develop locally, thereby increasing the probability of ectopic pregnancy. The specific manifestations are as follows: ① Amenorrhea: In addition to interstitial tubal pregnancy with a longer history of amenorrhea, most patients have amenorrhea for 6 to 8 weeks, and about 20 to 30% of patients have no obvious history of amenorrhea; ② Abdominal pain: When abortion or rupture occurs, the patient suddenly feels a tearing pain in the lower abdomen, often accompanied by nausea and vomiting. If blood accumulates in the rectouterine陷凹, there may be a sensation of rectal distension. With increased intraperitoneal hemorrhage, blood flows from the pelvis to the entire abdomen, forming a general abdominal pain. Stimulation of the diaphragm can cause radiating pain in the scapula; ③ Vaginal bleeding: There is often irregular vaginal bleeding, dark red in color, small in amount, and not stopping, generally not exceeding the amount of menstrual blood. With vaginal bleeding, degenerated endometrial tube-like or fragmented material may be excreted; ④ Syncope and shock: Due to acute intraperitoneal hemorrhage and severe abdominal pain, mild cases may experience syncope, and severe cases may develop hemorrhagic shock.

　　4. Menstrual disorders: Invaded by ectopic endometrium, the ovarian parenchymal tissue is destroyed, affecting hormone metabolism and leading to menstrual irregularities and increased vaginal bleeding during menstruation. Some individuals may also experience spotting before menstruation.

　　5. Sexual intercourse pain: refers to pain of varying degrees and nature during sexual intercourse.

　　Endometriosis of the bladder refers to the condition where endometrial tissue migrates to the bladder mucosa due to surgery or other reasons. The ectopic uterine mucosa, subject to the cyclical changes of hormones in the body, also shows changes such as secretion, proliferation, and bleeding. Therefore, when the menstrual period arrives, the ectopic endometrial tissue may cause pain and bleeding, which will disappear after the hormones in the body return to normal. Common symptoms of bladder endometriosis include:
　　1. Dysmenorrhea:This is a common and prominent symptom, usually secondary, meaning that patients did not experience pain during their menstrual periods before, but started to have dysmenorrhea from a certain period. It can occur before, during, and after the menstrual period. Some dysmenorrhea is severe and difficult to bear, requiring bed rest or medication for pain relief. The pain often worsens with the menstrual cycle. Due to the rising estrogen levels, the ectopic endometrium proliferates and swells, and if affected by gestational hormones, it may cause bleeding, stimulate local tissues, and result in pain. In the case of intraperitoneal endometriosis, it can also promote uterine muscle contraction, making dysmenorrhea more pronounced. In cases where there is no bleeding from the ectopic tissue, dysmenorrhea may be caused by vascular congestion. After menstruation, the ectopic endometrium gradually atrophies and the dysmenorrhea disappears. In addition, in pelvic endometriosis, many inflammatory processes can be detected, which are likely to be accompanied by active peritoneal lesions, thereby producing prostaglandins, kinins, and other peptide substances that cause pain or tenderness. However, the degree of pain often does not reflect the extent of the disease detected by laparoscopy. The psychological condition of women can also affect the perception of pain.
　　2. Menorrhagia:Intraperitoneal endometriosis often results in increased menstrual blood volume and prolonged menstrual periods. This may be due to increased endometrial tissue, but it is often accompanied by ovarian dysfunction.
　　3. Infertility:Patients with bladder endometriosis often suffer from infertility. Among them, primary infertility accounts for 41.5-43.3%, and secondary infertility accounts for 46.6-47.3%. Pelvic endometriosis can often cause adhesions around the fallopian tubes, affecting the retrieval of oocytes or leading to tubal obstruction, or it may affect the normal process of ovulation due to ovarian lesions, causing infertility. However, some people believe that long-term infertility without a menstrual cessation period may increase the risk of endometriosis; once pregnant, the ectopic endometrium is suppressed and atrophies.

　　Endometriosis of the bladder refers to the condition where endometrial tissue migrates to the bladder mucosa due to surgery or other reasons. The ectopic uterine mucosa, subject to the cyclical changes of hormones in the body, also shows changes such as secretion, proliferation, and bleeding. Therefore, when the menstrual period arrives, the ectopic endometrial tissue may cause pain and bleeding, which will disappear after the hormones in the body return to normal. General preventive measures for endometriosis of the bladder are as follows:

　　1. Avoid unnecessary, repetitive, or rough gynecological bimanual examination during the menstrual period to prevent the ejection of endometrial tissue into the bladder, which may cause endometrial bladder implantation.

　　2. Gynecological surgery should avoid being performed close to the menstrual period. If it is necessary to perform it, the operation should be gentle to avoid squeezing the uterine body, otherwise it is possible to push the endometrium into the bladder or abdominal cavity.

　　3. Timely correct the overflexed uterus and cervical canal stenosis, so that the blood flow is smooth, avoiding stasis and causing retrograde flow.

　　4. Strictly control the operation procedures of fallopian tube patency test (aerotubation, hydrotubation) and contrast, and do not perform it during the menstrual period just cleaned or directly during the scraping cycle, in order to prevent the endometrial fragments from being pressed into the pelvic cavity through the fallopian tube.

　　5. Pay attention to preventing the overflow of uterine contents into the pelvic cavity during cesarean section and cesarean section for fetus extraction. When closing the uterine incision, do not let the suture thread pass through the endometrial layer. Before closing the abdominal wall incision, apply normal saline irrigation to prevent endometrial implantation into the bladder.

　　If the patient has symptoms such as periodic rectal and bladder bleeding, defecation pain during the menstrual period, the first consideration should be endometriosis of the rectum and bladder. Bladderoscopy or rectoscopy may be performed if necessary, and tissue should be taken for pathological examination if there are ulcers. Abdominal wall scars with periodic hard nodules and pain, and a history of laparoscopic abdominal suspension, cesarean section, or cesarean section, can also establish the diagnosis. Patients with suspected cases that respond to drug treatment can also be diagnosed. It is as far as possible to take tissue (tissue resection or liver biopsy needle) for pathological examination for local masses close to the body surface, which can be diagnosed.

　　The ultrasound image of the endometrioma is granular and fine. If the fluid is thick and there are endometrial fragments floating inside, it is easy to resemble the echo characteristics of hair-containing fat in teratoma, showing as small fine light strips within the fluid, distributed in parallel dashed lines. Sometimes there is a partition inside, dividing it into several cavities of different sizes, and the echoes between the cavities are inconsistent, often adhering to the uterus, and the boundaries between the two are unclear. Teratoma generally has clear boundaries of the cyst. Endometrioma of the ovary is also easy to confuse with the sonogram of adnexal mass and tubal pregnancy, so it should be distinguished according to the clinical characteristics. In addition, the use of vaginal probe, making the mass close to the near field of high-frequency sound, has its advantages in the identification of pelvic mass nature, which can determine the nature and source of the mass, and can also puncture and aspirate the fluid or perform biopsy under ultrasound guidance to clarify the diagnosis.

　　X-ray examination: It can be performed as a separate pelvic air contrast, pelvic air contrast and uterine tubal iodine oil contrast, and as a separate uterine tubal iodine oil contrast. Most patients with endometriosis have adhesions of the internal reproductive organs and adhesions with intestinal loops. The ectopic endometrium is most easily implanted in the rectouterine pouch, so the adhesions of the internal reproductive organs are more likely to occur in the rectouterine pouch, making it shallow, especially in the lateral view of pelvic air contrast. Adhesions between the fallopian tube and ovary can form adhesion masses, which are clearer in the film or air contrast. Iodine oil uterine tubal iodine oil contrast can maintain patency or be less patent. Often, in the 24-hour follow-up film, iodine oil is poorly coated due to adhesions, showing as small mass-like or unevenly sized dot-like snowflake-like appearance. In combination with the exclusion of other infertility causes and the history of dysmenorrhea, it can help in the diagnosis of endometriosis.

　　Laparoscopy: An effective method for diagnosing endometriosis. The latest fresh implants are seen as yellow small blisters; the most biologically active are large flame-like hemorrhagic foci; most scattered lesions merge into brownish plaques and植入 into the deep tissue; the sacrospinous ligament thickens, hardens, and shortens; pelvic peritoneal scars form, shallowening the uterine rectal pouch; ovarian implants are often located at the free margin and dorsal side of the ovary, initially as 1-3mm granulomatous foci, gradually developing into chocolate cysts, with a grayish-blue surface, mostly bilateral, adhering to each other, facing the uterine rectal pouch, and widely adhering to the uterus, rectum, and surrounding tissues. In stages I and II, the fallopian tubes show no abnormalities; in stages III and IV, the tubes cross over the chocolate cyst, are passively elongated, show edema, limited peristalsis, and the ostium is mostly normal, patent or not patent. Hysterosalpingography should be performed during laparoscopy.

　　Points to note for the dietary treatment of endometriosis of the bladder:

　　1, Foods with a cold nature should be avoided in the treatment of endometriosis of the bladder. Pay special attention to avoiding excessively hot soups and dishes before and during menstruation, as well as cold foods, which are all contraindicated.

　　2, Cereals, legumes, and tubers can be consumed as staple foods without any need to avoid them.

　　3, Fatty and greasy foods are prone to causing blood stasis, so it is best to eat them in moderation. For patients with endometriosis of the bladder, light and疏通 foods are more suitable.

　　4, Dried fruits should not be avoided and can be eaten at any time. They help in nourishing the body and promoting blood circulation. Walnuts are warming and tonifying, and jujubes and longans are beneficial for tonifying qi and nourishing blood, making them more suitable for consumption.

　　5, Poultry, livestock, eggs, milk, and fresh fish are generally suitable for consumption, and are more effective for tonifying qi and nourishing blood in patients with a deficiency of both qi and blood. Snails, clams, crabs, and turtles are cool in nature and should be eaten in moderation. It is best to avoid overly fatty meats.

　　6, Eating foods that tonify and invigorate the body can help promote blood circulation and alleviate pain. These are especially suitable for patients with endometriosis who have a deficiency of both qi and blood.

　　7, Foods for the treatment of endometriosis are found in vegetables such as rapeseed, shepherd's purse, amaranth, seaweed, cucumber, luffa, winter melon, eggplant, chive white, bamboo shoots, and lotus root, which are all cool in nature. It is best to eat them sparingly before and after menstruation, and never raw. Chive white can disperse wind and cold, unblock the liver meridian, and is beneficial to eat. Black fungus has the effect of harmonizing the blood, and can be eaten in larger quantities.

　　8, Fruits are generally consumed raw, and patients with endometriosis of the bladder and endometrial lesions should also avoid them before and during menstruation.

　　9, Foods with a sour and astringent taste should be avoided as they may lead to blood stasis and qi stagnation. Spicy and warm foods are beneficial for promoting circulation, but they should not be consumed excessively as they may exacerbate pain due to excessive stimulation.

　　10. Alcoholic beverages can warm the yang and open the meridians, promote the circulation of Qi, and dispel coldness, which can be appropriately consumed to relieve blood stasis and pain. Spices such as芥末 (mustard), 茴香 (fennel), 花椒 (Sichuan pepper), and 胡椒 (black pepper) also have warming and promoting properties. Rose can regulate Qi and relieve anxiety, harmonize the blood and dissipate blood stasis, and is good for seasoning. Boiling ginger with brown sugar can replenish Qi, benefit the middle, dispel coldness, and activate blood circulation. Adding ginger's warmth enhances its ability to promote blood circulation. Drinking it daily is quite beneficial.

　　Bladder endometriosis is a deep nodular lesion with pathological manifestations similar to adenomyosis. Therefore, the therapeutic effect of commonly used endometriosis drugs such as high-efficiency progesterone, contraceptives, and gonadotropin-releasing hormone analogs is only about 33%, and symptoms may recur after discontinuation of medication. They are only used for patients with small lesions, no urinary system symptoms, or those who are not suitable for surgery, and medication is used as a palliative measure or as an adjuvant treatment for surgery.

　　Gonadotropin-releasing hormone agonists are currently recognized as the most effective drugs for treating endometriosis, with a recommended course of treatment of six months, and are the most commonly used drugs in developed countries. In recent years, their clinical application in China has increased significantly. The effect of monotherapy is not ideal, and symptoms may recur after discontinuation of medication. They are only used for palliative treatment for patients with small lesions, no urinary system symptoms, or those who are not suitable for surgery or refuse surgery, and are generally used as adjuvant treatment for surgery. The purpose of applying gonadotropin-releasing hormone agonists before surgery is to reduce the size of the lesion and the uterus, alleviate pelvic adhesions and congestion, inhibit the formation of physiological ovarian cysts, keep the endometrium in the bladder in a suppressed or atrophic state, and clearly separate the edges from normal mucosa, which is conducive to surgical resection and can prevent recurrence after surgery.

　　After the diagnosis of bladder endometriosis, endocrine treatment with mifepristone is supplemented before and after surgery. Mifepristone 12.5mg is administered once a day, and surgery is performed after 1 to 3 months of treatment to keep the ectopic endometrium in the bladder in a suppressed or atrophic state, with clear boundaries between the edges and normal mucosa, which is conducive to surgical resection and can prevent recurrence after surgery.

　　Medication can be an effective and feasible palliative measure for young patients with a desire for childbirth and those whose surgery cannot be completely removed or who have other pelvic endometriosis, etc. Due to the high risk of recurrence and malignancy after discontinuation of medication, regular checks should be conducted during the medication period.