There is a wide range of uterine lesions, including benign lesions, malignant lesions and uterine developmental abnormalities, which often lead to abnormal uterine bleeding, infertility, abdominal pain and other symptoms that greatly affect women’s quality of life. Common benign lesions include uterine fibroids, endometrial polyps, uterine adhesions, endometrial hyperplasia and adenomyosis; malignant lesions include endometrial cancer, endometrial mesenchymal sarcoma, myoma or polyp malignancy, etc.; uterine developmental abnormalities mainly include double horn, septum, stump horn, unicorn and T-shaped uterus, etc. Before the 1980s, many uterine pathologies could not be clearly diagnosed or could not be treated or open dissection of the uterus was performed, which brought greater trauma to patients. In the past 30 years, with the gradual application and promotion of hysteroscopy in the clinic, many uterine lesions have been well treated, and its minimally invasive, safe and efficient, replacing many traditional surgical methods, how to better grasp the indications for hysteroscopic treatment of various uterine lesions is the primary problem facing physicians.
1.Benign lesions of the uterine cavity
1.1, uterine fibroids: uterine fibroids are the most common benign tumors of the genitalia, mostly seen in women of childbearing age, with increased menstrual flow and anemia as their common clinical symptoms. Interstitial fibroids account for 60%-70% and submucosal fibroids account for 10%-15%. Submucosal fibroids and some interstitial fibroids are suitable for hysteroscopic myomectomy (TCRM). Submucosal fibroids are routinely classified into 3 types: type 0 for leiomyosarcoma with a clitoris; type I for fibroids that protrude into the uterine cavity >50%; and type II for fibroids that protrude into the uterine cavity <50%.
(1) Submucosal fibroids suitable for hysteroscopic resection: type 0 fibroids are unlimited in size; type I and II fibroids are usually less than 5 cm and more than 5 mm from the plasma layer of the uterus; small asymptomatic submucosal fibroids with a history of infertility also need to be removed.
(2) Intramural myomas suitable for hysteroscopic resection: the size of the myoma (usually less than 5 cm), the degree of endometrial protrusion, the presence of clinical symptoms and the operator’s operating level should be taken into account. For larger fibroids less than 5 mm from the plasma layer of the uterus, laparoscopic resection is recommended; for fibroids that cannot be removed by hysteroscopy in a single operation, a second operation is feasible; for fibroids with less endoplasia that the patient requires to be treated by hysteroscopy, windowing (removal of the pseudo-envelope near the cavity of the uterus) can be performed first, followed by a second operation one month later.
(3) Multiple submucosal fibroids: For young patients with fertility requirements who need to preserve the uterus, care should be taken to preserve as much normal endometrial tissue as possible when performing hysteroscopic removal of fibroids. For patients with fibroids, there are often as many as 20-30 submucosal fibroids, so it is not necessary to remove all of them in one operation, but to remove the larger ones and those with obvious internal protrusions, and to review the hysteroscopy after 2-3 courses of GnRH-a treatment after the operation, and to perform a second operation if there are still submucosal fibroids. Assisted reproduction is recommended as soon as possible after surgery.
1.2, endometrial polyps: endometrial polyps are divided into three types: functional polyps, nonfunctional polyps and adenomatous polyps, commonly found in women aged 30-60 years, with a reported incidence of 5.7% in China. The pathogenesis of polyps is not fully understood and cannot be treated medically or prevented. Surgery is a reasonable option, and previous scraping or clamping cannot achieve satisfactory results. The malignancy rate of endometrial polyps is low, but atypical hyperplasia of polyp glands, such as atypical adenomyomatous polyps of the uterus, is sometimes seen clinically and can develop into endometrial adenocarcinoma. For patients with atypical adenomyomatous polyps who are young or have fertility requirements, the uterus can be preserved as long as the polyps are completely excised and followed closely, supplemented with highly effective progesterone therapy if necessary. For those who do not have reproductive requirements or are older and cannot be followed closely, hysterectomy may be considered.
1.3, endometrial hyperplasia: endometrial hyperplasia is mostly caused by long-term continuous stimulation of estrogen, and is divided into three types: simple hyperplasia, complex hyperplasia and atypical hyperplasia, which can occur from adolescence to late menopause, with high incidence, and mostly leads to abnormal uterine bleeding. Atypical hyperplasia is precancerous and may develop into endometrial cancer. Treatment options are selected based on the patient’s age, fertility requirements, and severity of the lesion. Hormonal drug therapy is preferred for simple and complex hyperplasia. TCRE is feasible for those who have contraindications to drug use or drug therapy is ineffective, have no fertility requirements, require uterine preservation or cannot afford hysterectomy, with an efficacy of 88% to 95%, which is minimally invasive, safe, effective and does not affect ovarian function. In patients with atypical endometrial hyperplasia, TCRE is feasible for those who are young, have no fertility requirements or cannot afford hysterectomy; partial endometrial resection (only the functional layer of endometrium is removed) is feasible for those who are young and have fertility requirements, and postoperative adjuvant high potency progesterone or GnRH-a therapy; hysterectomy is performed for those who are older and have no fertility requirements.
1.4. Uterine adhesions: Uterine adhesions are mainly due to mutual adhesions of the myometrial wall caused by the destruction of the basal layer of the endometrium, which can cause reduced menstruation, amenorrhea, abdominal pain and infertility. Once the adhesions occur, they must be treated surgically. The treatment by simple dilation is blind and it is impossible to understand the specific situation in the uterine cavity. Hysteroscopic cavity adhesion separation (TCRA) has become the standard procedure for the treatment of cavity adhesions, and prevention of cavity re-adhesions after TCRA is the key to successful treatment, especially for moderate to severe cavity adhesions. Hysteroscopy at 1 and 3 months postoperatively is necessary to improve the outcome by detecting and simultaneously separating membranous adhesions in the early postoperative period. Promoting the growth of endometrium is also an important part of preventing re-adhesion, and high-dose estrogen applied continuously or cyclically for 3 months is more effective.
1.5. Adenomyosis: The incidence of adenomyosis is increasing year by year, mostly in women of childbearing age, with excessive menstruation and gradually increasing dysmenorrhea as its main symptoms. The treatment depends on the patient’s age, symptoms and fertility requirements. The first choice is pharmacological treatment. For those who are young, have no fertility requirements or require preservation of the uterus or cannot afford hysterectomy, hysteroscopic endometrial resection (or removal) is feasible, and the results are better for superficial adenomyosis (≤2.5 mm from the mucosal layer), while the recurrence rate is higher for deeper invasion.
TCRM for submucosal adenomyoma is not easily distinguishable from fibroids at the time of surgery and requires pathological confirmation. type 0 adenomyoma can be completely removed hysteroscopically and does not require adjuvant medication postoperatively. For type I and II adenomyoma or cystic adenomyoma that cannot be completely removed during surgery, adjuvant medication is needed after hysteroscopic surgery to improve the efficacy, such as GnRH-a and pregnenetrienone.
2. Malignant lesions in the uterine cavity
2.1. Endometrial cancer: For young patients with early endometrial adenocarcinoma who have fertility requirements, partial endometrial resection can be performed and postoperative adjuvant GnRH-a or highly effective progesterone therapy can be used, and hysteroscopy and diagnostic scraping will be reviewed after 3 months. After childbirth, close follow-up or routine surgical treatment for endometrial cancer is recommended.
2.2 Endometrial mesenchymal sarcoma: Endometrial mesenchymal sarcoma comes from endometrial mesenchymal cells and is divided into two categories: low malignancy and high malignancy. The tumor is often polyp-like or nodular, sometimes it is difficult to be diagnosed before surgery, and misdiagnosed as endometrial polyp or submucosal myoma during hysteroscopy.
3.Uterine development abnormalities
3.1, septal uterus: The septum is formed when the embryo develops to 10~12 weeks and the septum is not absorbed or not completely absorbed after the merging of bilateral paramedian tubes, which may cause infertility, miscarriage, preterm delivery or abnormal fetal position. The diagnosis of septal uterus can be clarified by ultrasound, imaging, MRI or hysteroscopy. There are incomplete septate uterus and complete septate uterus (the septum reaches below the endocervix). The indications for surgery are infertility, a history of 2 or more spontaneous abortions, and preparation for assisted reproduction. The traditional method is open surgery, in which the septum is removed together with part of the uterine wall, which is more invasive and pregnancy is not possible until 2 years after the operation. Hysteroscopic hysterectomy of the septum (TCRS) is now the standard procedure for the treatment of septum, with minimal trauma, rapid recovery, and pregnancy 3 months after surgery. Hysteroscopy combined with laparoscopy for TCRS is very important. Laparoscopy provides further insight into the appearance of the uterus, clarifies the diagnosis, and monitors the uterine cavity operation.
In septated uterus with a markedly depressed fundus, care should be taken when removing the septum, without forcing the uterine cavity to be completely normal postoperatively, because a thin fundus may cause uterine rupture in late pregnancy, and it is generally better to maintain a fundal thickness of 1.5 to 2 cm. Studies have shown that even if a septum of 1 cm or less remains after surgery, it has no effect on pregnancy. In patients with a history of multiple miscarriages, recurrent miscarriages still occur in about 10% of patients after TCRS, and further search for other etiologies is needed. In patients with complete bicervical septum, part of the septal tissue in the cervical canal needs to be preserved during surgery to prevent cervical insufficiency, and cesarean section is needed to end delivery after full-term pregnancy.
3.2. Bicornuate uterus: due to incomplete fusion at the base of the uterus, it is easily confused with septal uterus during ultrasound and imaging, which can lead to miscarriage, preterm delivery and abnormal fetal position. For those who have more than 2 spontaneous abortions, hysteroplasty should be performed, and the traditional method is open surgery. With the gradual development of hysterolaparoscopy and the gradual proficiency in operating techniques, the use of combined hysterolaparoscopic surgery for correction of bicornuate uterus has become a reality. The incision is closed longitudinally with laparoscopic sutures and interrupted full-layer sutures using absorbable thread. The operation is minimally invasive and safe, reducing the risk of pelvic adhesions due to open surgery, and pregnancy is possible 1 year after the operation.
3.3. Stumped uterus: It is caused by abnormal development of one side of the paramedian tube and may be accompanied by abnormal development of the urinary tract on the stumped side. In most cases, the uterus does not communicate with the contralateral uterine cavity, and the uterine cavity appears unicornuate on hysteroscopy. If there is no endometrium in the stump or if the endometrium is not functional, it is usually asymptomatic and can be left untreated. In case of recurrent miscarriage after pregnancy, the hysteroscopic removal of part of the muscle wall tissue adjacent to the stump on the normal side of the uterine cavity under ultrasound or laparoscopic supervision may be performed to enlarge the uterine cavity to facilitate pregnancy. If the endometrium is functional and does not pass with the normal uterine cavity, it is easy to form blood in the uterine cavity and abdominal pain occurs, which used to require hysterectomy of the residual horn.
3.4. T-shaped uterus: clinically rare, hysteroscopy shows bilateral wall coalescence and T-shaped uterine cavity morphology. If the patient has a history of unexplained infertility or miscarriage, a hysteroscopic needle electrode is used to cut through the bilateral walls of the coalescing uterus, and the cavity can be trimmed to a normal shape.
4.Uterine cavity foreign body
4.1. IUD embedding or residue: IUD improperly placed, placed for too long or not removed in time after menopause can lead to ring embedding or residue during IUD removal. Under the supervision of B ultrasound, the use of hysteroscopy to remove the embedded or residual IUD is safe and reliable. If the preoperative ultrasound indicates that the ring is less than 3 mm from the plasma layer of the uterus, laparoscopic supervision is recommended for removal of the ring, which often penetrates the uterus and occasionally into the intestine. After removal of the IUD, if the uterine perforation is small and there is no active bleeding, the uterine constrictor can be given; if the perforation is large or there is active bleeding, the uterine perforation needs to be sutured laparoscopically; intestinal injury generally has a small perforation and can be sutured laparoscopically.
4.2, embryo residue: clinically common after miscarriage, midterm induction of labor or full-term delivery, mostly with abnormal uterine bleeding, intrauterine occupancy by ultrasound, hysteroscopy can be clearly diagnosed. Patients often have a history of uterine clearance, sometimes for angular pregnancy or placental implantation. Hysteroscopic removal of old residual embryos is safer. In case of horn pregnancy with large residual embryos (>3 cm in diameter), which are more difficult to remove by hysteroscopy, laparoscopic hornotomy for embryo retrieval is feasible. In case of placental implantation with a large area, hysteroscopic removal of the embryos should be performed with a certain thickness of the uterine wall to prevent uterine perforation, preferably under ultrasound supervision. For fresher embryo residues, if the uterus is large, the residual tissue is large, there is a possibility of placental implantation, and the patient’s blood chorionic gonadotropin (HCG) is high, hysteroscopic treatment needs to be applied cautiously, and it is more likely that hemorrhage will occur during the operation. It is safer to give medication to kill the embryo first and then perform hysteroscopy after the blood HCG drops to low or normal values. If there is more bleeding, hysteroscopic surgery can be performed quickly, and it is not mandatory to remove the placenta completely in one operation, especially for placenta implantation, a second operation is feasible. If the uterus bleeds more after the surgery and the drug treatment such as contraction is not effective, the balloon can be left in the uterus to stop the bleeding.
4.3. Residual sutures of cesarean incision: If the uterus bleeds abnormally after cesarean section, the drug conservative treatment is ineffective, and there is no abnormality in the uterine cavity by B-ultrasound, we should consider the possibility of residual sutures of incision in the uterine cavity, and hysteroscopy can make a clear diagnosis. Caution is required during hysteroscopy and ultrasound supervision is recommended to prevent uterine perforation.
In conclusion, today, when the use of hysteroscopy has become more popular, as a clinician, you cannot take the risk to perform the procedure, and you need to choose the indications reasonably for the uterine cavity lesions to be truly minimally invasive, safe and effective.