Low-pressure endometrial aspiration sampling —- a more minimally invasive and comfortable endometrial diagnostic technique Clinic-based low-pressure endometrial aspiration sampling has largely replaced diagnostic curettage in Europe and the United States, providing a minimally invasive option for the diagnosis of endometrial cancer, hyperplasia and other endometrial pathologies as the first-line diagnostic tool for endometrial lesions.
What is the endometrial low-pressure aspiration sampling technique?
The endometrial aspiration sampling device is a cannula with a piston core and an outer sheath. When the trocar is placed in the uterine cavity, the piston core is pumped backwards, thereby creating a negative pressure that draws endometrial tissue into the sampling device. Low-pressure endoaspiration devices (e.g., Pipelle, Endocell) are the most commonly used endo-sampling devices. It consists of a bendable polypropylene core and sheath, less than 3 mm in diameter, with a 2.4 mm or smaller diameter lateral hole at the distal end of the sampler, through which endothelial tissue is drawn into the lumen. The bendability of the sampler allows it to be adapted to the morphology of the uterine cavity and reduces the incidence of spasm. Typically endometrial sampling can take 5-15% of the endometrium area. The failure rate for low-pressure endometrial aspiration biopsy is approximately 0-8%.
What are the advantages of endometrial low-pressure aspiration sampling?
The advantages of endometrial sampling compared to diagnostic scraping are
It can be performed on an outpatient basis, without the need for an operating room (given the current conditions and procedures in our hospital outpatient clinics, we still recommend that endometrial sampling be performed in an outpatient procedure). It can be performed without anesthesia or with local anesthesia only. No or only slight cervical dilatation is required. Reduced chance of uterine perforation (0.1-0.2% for outpatient endometrial sampling; 0.3-2.6% for curettage). Short operation time, the actual sampling time is only 5-15 seconds inexpensive. Endometrial sampling with the IUD in place is also possible.
Can low pressure aspiration sampling of the endometrium miss the diagnosis?
Numerous studies have shown that endometrial sampling techniques can obtain enough endometrium for diagnosis. Specimens can be obtained by sampling in over 90% of patients. It is well documented that the sensitivity and specificity of endometrial sampling for the diagnosis of endometrial cancer is close to 100%. However, it should be noted that these sampling devices do not allow direct visualization of the uterine cavity and are therefore more effective in diagnosing extensive endometrial lesions than localized lesions such as endometrial polyps. However, strict knowledge of the indications for the implementation of endometrial sampling techniques and the correct application of diagnostic tools for endometrial lesions can minimize the risk of missed endometrial lesions.
What are the indications and contraindications for endometrial low-pressure aspiration sampling?
Indications.
Women with abnormal uterine bleeding or certain abnormal cervical cytology findings to evaluate for endometrial tumors Women at high risk for endometrial tumors or women with a history of endometrial tumors Endometrial cancer screening Women treated for endometrial cancer with preservation of fertility should undergo regular endometrial sampling.
Women with Lynch syndrome (hereditary nonpolyposis colon cancer) need to be tested for endometrial cancer. There are no routine screening guidelines for women with other risk factors and decisions need to be made on an individual basis.
Bleeding tendency is a relative contraindication because of the potential for heavy bleeding in these patients. Overall, endothelial sampling can be performed in patients on anticoagulation therapy if coagulation parameters are stable and within the standard treatment range. If the bleeding tendency is uncontrolled and the patient requires an endothelial biopsy, a specialist dealing with the patient’s coagulation problems should be consulted. These patients may need to reverse their anticoagulant therapy or receive other treatments (e.g., desmopressin). Women with uncontrolled bleeding tendencies should have an endometrial biopsy performed in the operating room, with blood preparation and anesthesia.
In cases of acute vaginal, cervical, or pelvic infection, endometrial biopsy should be postponed until the infection is controlled, if possible.
In rare cases where endometrial sampling is required in patients with cervical cancer, obstructive cervical lesions may be a relative contraindication in a subset of patients and may result in an increased risk of bleeding and uterine perforation. Endometrial sampling can be performed without complications when the intrauterine device (IUD) is in place. There are no studies on whether endometrial sampling with an IUD in place affects the diagnosis.
Is diagnostic curettage completely unnecessary after endometrial aspiration sampling?
Further diagnostic curettage is not necessary when
The pathologic diagnosis of aspirated endometrium is clear, and if the pathologic diagnosis is clearly endometrial cancer, further diagnostic scraping is not necessary.
If the pathological diagnosis of aspiration endometrium is found to be normal endometrium, and the symptoms of abnormal uterine bleeding are relieved by hemostatic and anti-inflammatory symptomatic treatment or hormonal treatment, and the ultrasound does not suggest abnormal occupancy, further treatment is not needed.
Further diagnostic curettage is required in the following cases (in these cases, hysteroscopically guided diagnostic curettage is recommended rather than blind curettage)
Aspiration of endometrial pathologic diagnosis does not reveal endometrial lesions, but symptoms persist with symptomatic management.
Aspiration of endometrial pathology does not reveal endometrial lesions, but ultrasound still suggests intrauterine occupancy or endometrial heterogeneity.
Endometrial lesions were found by aspiration endopathology diagnosis, and further diagnosis is needed to exclude the possibility of higher grade lesions.
Women at high risk of endometrial cancer whose outpatient endometrial biopsy does not reveal lesions who have an insufficient amount of tissue taken from an outpatient endometrial biopsy for pathologic diagnosis who have cervical stenosis that prevents outpatient biopsy and must undergo other procedures such as hysteroscopy or laparoscopy are advised to skip endometrial sampling and proceed directly to diagnostic curettage in the following cases
Treatment of incomplete miscarriage, refractory miscarriage, indolent miscarriage, infected miscarriage and induction of labor.
Initial treatment of gravida.
Temporary management of prolonged or heavy vaginal bleeding where hormonal therapy has failed.
Aspiration (without cervical dilatation) can be used to treat postpartum bleeding due to retained pregnancy What are the side effects and complications of endometrial aspiration sampling?
The most common side effect of endometrial sampling is cramping, which resolves quickly after the procedure is completed. High-pressure aspiration devices cause more severe cramping than low-pressure devices because the former are harder and have more suction force to aspirate more endometrial samples. Many women experience a small amount of vaginal bleeding or spotting for several days after the procedure.
Vaso-vagal reactions are not commonly associated with endothelial sampling operations. Allowing the patient to eat and drink appropriately before the procedure and using analgesic medications or local anesthesia to reduce pain can usually prevent such reactions. The risk of uterine perforation is approximately 1-2/1000.
Rare complications include massive uterine bleeding (especially in patients with undiagnosed coagulopathy), uterine perforation (risk 0.1-0.3%), pelvic infection, and bacteremia (including sepsis and endocarditis).
What should I expect after undergoing endometrial aspiration sampling?
Patients should remain in a semi-recumbent position for several minutes after the procedure to reduce the chance of vasovagal reactions. Thereafter, if the patient is free of dizziness and heavy bleeding, he/she can leave the clinic. Nonsteroidal anti-inflammatory drugs may be applied to manage spasticity, although sustained spasticity rarely occurs.
Patients should be seen immediately if fever occurs, cramping lasts 48 hours or longer, pain increases, vaginal drainage is offensive, or bleeding is greater than menstrual flow. The operation does not interfere with the patient’s daily activities, including sexual intercourse.