[Gynecological Hysteroscopy] Techniques for Preventing and Treating Complications of Hysteroscopic Surgery

Hysteroscopic diagnosis and treatment of intrauterine lesions is minimally invasive and effective. However, due to the need for energy equipment, distension media, intrauterine pressure, and the limited surgical space and inability to suture, hysteroscopic surgery presents different complications compared to traditional surgery, even posing a risk of death. Common complications include uterine perforation, bleeding, fluid overload, hyponatremia, air embolism, and postoperative uterine rupture. This article will explore the causes and prevention methods of hysteroscopic surgical complications to improve the safety of hysteroscopic surgery.

I. Bleeding

The endometrium has a rich blood supply. During endometrial resection, to avoid bleeding, the cutting depth must be ensured to be 2-3 mm below the endometrium. The main cause of bleeding during hysteroscopic surgery is deep damage to the myometrium beneath the endometrium.

High-risk factors: Uterine perforation, arteriovenous fistula, placenta accreta, cervical pregnancy, cesarean scar pregnancy, and coagulation disorders, etc.

Countermeasures: Preoperative drug conditioning (administration of oxytocin and hemostatic agents), intrauterine balloon compression, combined laparoscopic monitoring, and prophylactic uterine artery occlusion, etc.

The treatment plan is determined based on the amount, location, extent of bleeding, and type of surgery.

II. Uterine Perforation

High-risk factors: Cervical stenosis, history of cervical surgery, excessive uterine flexion, small uterine cavity, and inexperienced surgeon, etc.

Clinical Manifestations:

① Uterine cavity collapse, obscured vision;

② B-ultrasound images show free fluid around the uterus, or a large amount of perfusion fluid entering the abdominal cavity;

③ Hysteroscopy reveals the peritoneum, intestines, or greater omentum;

④ With laparoscopic monitoring, the uterine serosal surface may be translucent, blistering, bleeding, hematoma, or perforation;

⑤ Electrode insertion and damage to pelvic and abdominal organs can cause corresponding complications and symptoms.

Treatment: Carefully locate the perforation site and determine the treatment plan.

① Fundus perforation: The uterine fundus muscle is thickened, with relatively few blood vessels, resulting in less bleeding. Oxytocin and antibiotics can be used for observation.

② Lateral wall and isthmus perforation: Uterine blood vessels may be damaged, requiring immediate exploratory laparotomy. Bleeding at the perforation site can be stopped laparoscopically with bipolar electrocoagulation. Larger perforations require suturing.

③ Unclear situation: Laparoscopy should be performed, even if the patient's overall condition is normal, to observe for bleeding and its source. ④ Postoperative pain management: A comprehensive examination should be conducted within 24 hours post-surgery to manage pain. If uterine perforation is suspected, laparoscopy should be performed promptly.

Prevention:

① Strengthen cervical pretreatment and avoid forceful cervical dilation. If the patient is postmenopausal, misoprostol or similar medications should be used preoperatively to soften the cervix. If the patient has cervical stenosis, appropriate cervical dilators should be used to ensure successful hysteroscopy insertion.

② Combine ultrasound or laparoscopy as needed to clearly identify the lesion location and obtain a clear surgical field.

③ Train and improve the surgeon's surgical skills.

④ Use GnRH-α drugs as needed to shrink fibroids or uterine volume and thin the endometrium.

III. Excessive Irrigation Fluid Absorption Syndrome

During hysteroscopic surgery, the distension pressure and use of non-electrolyte irrigation media can cause fluid to enter the patient's body. When this exceeds the body's absorption threshold, a series of symptoms and signs may occur.

Clinical manifestations include bradycardia, elevated or decreased blood pressure, nausea, vomiting, headache, blurred vision, restlessness, mental confusion, and drowsiness. If not treated promptly, it can lead to convulsions, cardiopulmonary failure, and even death.

Precipitating factors include intrauterine hypertension, excessive absorption of the perfusion medium, and prolonged surgical time.

Treatment measures include oxygen therapy, diuretics, treatment of hyponatremia, correction of electrolyte imbalances and water intoxication, management of acute left ventricular failure, and prevention and treatment of pulmonary edema and cerebral edema.

Special attention should be paid to correcting dilutional hyponatremia. Sodium supplementation should be calculated and administered according to the following formula: Required sodium supplementation = (Normal serum sodium level - Measured serum sodium level) 52% × Body weight (kg). The initial supplementation dose should be 1/3 or 1/2 of the calculated total. Subsequent supplementation doses should be determined based on changes in the patient's level of consciousness, blood pressure, heart rate, pulmonary signs, and serum Na+, K+, and Cl- levels. Rapid, high-concentration intravenous sodium supplementation should be avoided to prevent a temporary state of cerebral hypoosmotic pressure, causing fluid to shift from the interstitial space to the intravascular space, leading to cerebral dehydration and brain damage.

The hysteroscopic bipolar system uses normal saline as the intrauterine perfusion medium, reducing the risk of hyponatremia, but the risk of fluid overload still exists.

Prevention:

① Cervical and endometrial pretreatment helps reduce the absorption of irrigation fluid;

② Maintain intrauterine pressure ≤ 100 mmHg or < mean arterial pressure;

③ Control the irrigation fluid difference between 1000 and 2000 ml;

④ Avoid excessive damage to the uterine wall.

IV. Gas Embolism

Gas embolism is a very rare but fatal complication of hysteroscopic surgery. During hysteroscopic surgery, air can enter the uterine cavity through the irrigation system's inlet tube, cervix, repeatedly inserted dilators, and hysteroscopic instruments, and then enter the venous system through the open sinuses during the procedure. Gas can enter the inferior vena cava, then the right heart, pulmonary artery, and ultimately the lungs, causing pulmonary hypertension, hypoxemia, circulatory failure, and cardiac arrest.

Tissue vaporization during the procedure and room air may enter the venous circulation through open blood vessels at the uterine cavity wound, leading to gas embolism. Gas embolism has a sudden onset and rapid progression. Early symptoms include decreased end-tidal PCO2, bradycardia, decreased PO2, and a loud water murmur in the precordial area. This is followed by increased blood flow resistance, decreased cardiac output, cyanosis, hypotension, tachypnea, and cardiopulmonary failure, leading to death.

Countermeasures: Immediately stop the procedure, administer positive pressure oxygen, and correct cardiopulmonary failure. Simultaneously, infuse normal saline to promote blood circulation, place a central venous catheter, and monitor cardiopulmonary artery pressure.

Specific measures: ① The mechanical pump used for intraoperative distending fluid injection should be equipped with a Y-shaped connector to prevent air from entering the infusion tubing. ② Set a reasonable distending fluid pressure; as mentioned earlier, the distending fluid pressure should generally not exceed 100 mmHg, while controlling the amount of distending fluid used. ③ During electrocautery, tissue vaporization can generate a significant amount of gas; using cold-blade instruments or minimizing the surgical time can reduce gas production. ④ After cervical dilation, the surgeon should maintain a closed cervix throughout the procedure, avoiding repeated insertion and removal of instruments from the uterine cavity. ⑤ Rapid Intraoperative Identification: Anesthesiologists should pay close attention to monitoring end-tidal carbon dioxide partial pressure during hysteroscopy, as a decrease in end-tidal carbon dioxide partial pressure is a sensitive early indicator of gas embolism.

⑥ Once gas embolism is detected, the surgery should be stopped immediately, the uterine fluid emptied, and a moist gauze pad placed in the vagina to prevent gas from entering. Immediately position the patient head-up, elevating the heart to reduce gas entry.

Prevention:

① Avoid head-down, hip-up position;

② Empty the air from the infusion tubing before surgery;

③ Perform cervical pretreatment to avoid rough dilation that could cause cervical laceration;

④ Strengthen intraoperative monitoring and emergency treatment.

V. Prevention of Intrauterine Adhesions

① Using a needle electrode to incise the mucosa and capsule of the protruding fibroid within the uterine cavity, followed by cutting the fibroid with a ring electrode, is crucial to preventing secondary intrauterine adhesions after surgery, minimizing damage to the surrounding normal endometrium.

② If there is a large exposed wound in the uterus or if preoperative GnRH-a treatment has resulted in low estrogen levels, appropriate postoperative estrogen can stimulate endometrial growth, accelerate epithelialization, and prevent intrauterine adhesions.

③ An IUD can also be placed at the end of the procedure. If there is significant bleeding during the procedure, it can be placed after menstruation resumes postoperatively. The physical support provided by the IUD helps prevent intrauterine adhesions.

VI. Infection

Causes:

① The doctor did not strictly follow aseptic procedures during the surgery;

② No rigorous examination of pelvic and vaginal secretions was performed preoperatively.

Prevention:

① Strictly adhere to surgical indications;

② Surgery is contraindicated during the acute phase of reproductive tract infections;

③ Postoperative antibiotics should be used as appropriate to prevent infection.

VII. Treatment Failure and Recurrence

Treatment failure or symptom recurrence can be considered for subsequent treatments, including a second hysteroscopic surgery, medication, or hysterectomy. It is particularly important to emphasize that hysteroscopic surgery is a conservative procedure for treating uterine diseases. Informed consent must be fully obtained before the procedure, and the procedure must never be performed against the patient's will.