Hysteroscopy refers to the use of a hysteroscope, a type of fiber optic endoscope, coupled with a distending medium to expand the uterine cavity. By inserting the endoscope into the uterine cavity, a cold light source illuminates the area, facilitating direct visualization of physiological and pathological changes in the cervical canal, internal cervical os, uterine cavity, and fallopian tube openings. This approach enables precise sampling of suspicious lesions for pathological examination and permits surgical treatment under direct visualization. Hysteroscopy can serve both diagnostic and therapeutic purposes for diseases involving the uterine cavity and cervical canal.
Indications for Hysteroscopic Examination
These include:
- Abnormal uterine bleeding.
- Suspected uterine cavity adhesions or malformations.
- Suspected retained products of conception.
- Imaging studies suggesting intracavitary lesions.
- Unexplained infertility or recurrent pregnancy loss.
- Abnormalities related to intrauterine contraceptive devices.
- Intracavitary foreign bodies.
- Post-hysteroscopic assessment.
- Early diagnosis and follow-up evaluation of endometrial cancer.
- Investigation of vaginal foreign bodies or space-occupying lesions in prepubertal females.
Indications for Hysteroscopic Surgery
These include:
- Endometrial polyps.
- Submucosal fibroids and selected intramural fibroids affecting the uterine cavity shape.
- Intrauterine adhesions.
- Uterine septum.
- Endometrial ablation.
- Removal of intracavitary foreign bodies, such as embedded contraceptive devices or retained products of conception.
- Tubal catheterization, fluid infusion, drug delivery, and sterilization under hysteroscopic guidance.
- Fertility-preserving treatment for atypical endometrial hyperplasia and early-stage endometrioid carcinoma.
- Uterine scar defects following cesarean section.
Contraindications
Absolute Contraindications:
- Severe systemic or surgical comorbidities that make the patient unsuitable for operative procedures.
Relative Contraindications:
- Acute episodes of pelvic or vaginal infections, or body temperature exceeding 37.5°C.
- Cervical scars that prevent adequate dilation.
- History of uterine perforation or uterine surgery within the past three months.
- Invasive cervical cancer or genital tuberculosis not treated with systematic anti-tuberculosis therapy.
- Active uterine bleeding or during menstruation.
Preoperative Preparation and Anesthesia
Timing of Examination
The procedure is optimally performed within one week after the end of menstruation when no intercourse has occurred between the end of menstruation and the procedure. During this period, the endometrium is in the early proliferative phase, which is thin and less prone to bleeding, with minimal mucus secretion, allowing easier identification of uterine cavity abnormalities.
Physical Examination and Vaginal Preparation
A thorough medical history is obtained, followed by a general physical examination, gynecologic evaluation, cervical cytology, and vaginal secretion analysis.
Additional Tests
These include tests such as complete blood count, coagulation profile, liver and renal function tests, fasting blood glucose, hepatitis virus screening, syphilis treponemal testing, HIV testing, β-hCG levels, and electrocardiography.
Fasting Before Surgery
Patients scheduled for hysteroscopic surgery fast for 6–8 hours preoperatively.
Anesthesia
Diagnostic hysteroscopy typically does not require anesthesia, though local cervical anesthesia may be applied. Operative hysteroscopy generally involves epidural anesthesia or intravenous sedation.
Procedure Steps
Procedure Workflow
Preparation
The patient is positioned in the lithotomy position. Routine disinfection and sterile draping are performed. The cervix is held with cervical forceps, the uterine depth and orientation are assessed using a uterine probe, and the cervix is dilated slightly beyond the outer sheath diameter of the hysteroscope. A liquid distention pump is connected, and pressure is adjusted so that the uterine cavity is distended with the medium. The hysteroscope is then gently inserted into the uterine cavity under direct visualization, and the flow rate of the distention medium is adjusted to maintain appropriate intrauterine pressure.
Uterine Cavity Observation
A panoramic assessment of the uterine cavity is conducted, including the uterine fundus, anterior and posterior walls, and bilateral tubal openings. The internal cervical os and cervical canal are observed during the withdrawal phase.
Intrauterine Procedures
Following diagnosis, quick and simple interventions such as removal of embedded intrauterine devices, excision of easily resectable endometrial polyps, or endometrial biopsy may be performed immediately. Longer or more complex hysteroscopic surgeries are scheduled for a later date and performed under anesthesia in the operating room.
Energy Sources
Energy sources used in hysteroscopic surgeries include high-frequency electrosurgical generators, monopolar and bipolar electrosurgical systems, electrocautery, lasers, and microwave devices.
Choice of Distention Medium
For monopolar electrosurgery or electrocautery, non-conductive 5% glucose solution is used as the distention medium.
For bipolar electrosurgery, saline is preferred to reduce the risk of excessive absorption of hypotonic fluids, which can lead to fluid overload syndrome.
In diabetic patients, 5% mannitol may be used for uterine distention.
Complications and Their Management
Hemorrhage
Hemorrhage may occur if the surgical excision extends 5–6 mm below the endometrium into the vascular layer of the uterine myometrium.
Risk factors for intraoperative bleeding include uterine perforation, arteriovenous malformations, cervical pregnancy, pregnancy at cesarean scar sites, and coagulation disorders.
Management should be tailored based on the volume, location, extent of bleeding, and type of surgery performed. Potential interventions include administering uterotonic agents (e.g., oxytocin, misoprostol), using a balloon catheter for compression, or performing uterine artery embolization.
Uterine Perforation
Perforation may occur during cervical dilation or hysteroscopic manipulation. Risk factors include cervical stenosis, a history of cervical surgery, excessive uterine flexion, a small uterine cavity, excessive dilation force, or lactational atrophy of the uterus.
Upon the occurrence of perforation, surgical procedures must be halted immediately, and the perforation site must be identified to determine the presence of adjacent organ damage.
Conservative treatment with oxytocin and antibiotics, along with close monitoring, may be sufficient if the patient is hemodynamically stable, there is no active bleeding, and no organ damage is detected. Large perforations or those suspected of vascular or organ injury require immediate surgical intervention.
Fluid Overload Syndrome Due to Excessive Absorption of Distention Medium
Also known as fluid overload-hyponatremia syndrome, this condition results from excessive absorption of distention medium, leading to fluid overload and/or dilutional hyponatremia. Without timely treatment, it can rapidly progress to acute pulmonary edema, cerebral edema, cardiac failure, or death.
Management includes halting the surgical procedure, administering oxygen, correcting electrolyte imbalances and water intoxication, addressing acute left heart failure, and preventing pulmonary and cerebral edema.
Preventive measures include the use of saline as the preferred distention medium, maintaining optimal but low intrauterine pressure for effective distention, controlling operative time, and staging complex surgeries when necessary.
Gas Embolism
Gas embolism is a rare but life-threatening complication of hysteroscopy, caused by the entry of gas into the bloodstream during the procedure.
Early signs include bradycardia, decreased oxygen saturation, and an audible “mill-wheel” murmur on precordial auscultation. Progression may result in cyanosis, reduced cardiac output, hypotension, tachypnea, and eventually cardiac and respiratory failure, leading to death.
Preventive measures encompass positive pressure ventilation, minimizing repeated instrument insertion and withdrawal from the uterine cavity, avoiding the Trendelenburg position, gentle cervical dilation, and venting air from tubing and instruments.
Immediate resuscitation is required in case of gas embolism. Given its rapid progression and severe consequences, prevention is crucial due to the low success rate of resuscitation.
Other Complications
Other potential complications include infections, intrauterine adhesions, and cervical canal adhesions. Specific management should be implemented upon occurrence.