Hysteroscopy: Managing and minimizing operative complications
Techniques to assess the site, spot imminent perforation, and avoid or correct the 5 most common types of problems.
Preoperative measures may decrease vascularity. In their analysis of 16 randomized and nonrandomized controlled trials published in the English literature between 1990 and 1996, Parazzini and colleagues15 found that preoperative danazol or GnRH agonists decreased the thickness and vascularity of the endometrium and shrank myomata, resulting in shorter operating times, less blood loss, and less intravasation of distending fluid.
Electrosurgical and gaseous complications
Most electrosurgical complications involve activation of an electrode at the time of perforation, or current diversion to the outer sheath.
Thermal injuries also can be caused by overheating of the return pad or use of a weighted speculum that has not fully cooled after removal from the autoclave. The latter can be avoided by immersing the entire speculum in cool saline for at least 1 to 2 minutes prior to inserting it into the vagina. The blade cools much faster than the weighted ball, so be sure to check both to prevent a perineal or buttock burn.
Perforation with an active electrode
This usually occurs when current is applied as the electrode is extended or the resectoscope is moved toward the fundus. It can be avoided if the electrode is activated only when moving it toward the operator.
Perforations with intraabdominal burns also have occurred during attempts to coagulate bleeders—especially in the cornual regions.
Diversion of current can be destructive
Genital tract injuries have occurred as a result of current diversion. Vilos and colleagues16 reported 13 electrical burns during endometrial ablation, and mention many more anecdotal reports. The usual cause: electrode insulation failure, which allows current to jump to the outer sheath of the resectoscope.
To avoid this, inspect all electrodes thoroughly before surgery and use them only once.
Capacitative coupling also diverts current
Since the sheath-within-a-sheath design of the resectoscope resembles a capacitor, high-voltage current can jump to the outer sheath without direct contact from the electrode. When Munro17 bench-tested electrosurgical generators and electrodes with and without insulation defects, he found that capacitative coupling with intact electrodes occurred more frequently with high-voltage coagulation current than with lower-voltage cutting current.
One way to avoid these injuries is to activate the electrode intermittently, with short bursts, rather than rolling back and forth over an area with continuous current. Another strategy is placing a damp sponge in the posterior vagina extending out the introitus; this protects the mucosa and perineal skin—especially in obese patients.
How to avoid return-pad injuries
Keep the patient’s thigh completely dry; ensure that the pad is flat against the skin at application, with no bubbles or creases; and use only return electrode monitor (REM) dispersive pads.
Especially when using vaporization electrodes, avoid prolonged activation of the electrode at high power. To minimize risk of vaporization, use a second dispersive pad connected to the first via a “y” connector to further disperse current and heat at the return pad.
Also, limit the use of coagulation current and use a maximum generator setting of 60 to 80 W in the coagulation mode.
Take steps to avert gas embolism, but watch closely for signs
Initial reports of this potentially fatal complication came mostly from laser ablation procedures, but gas embolism can occur during all diagnostic and operative hysteroscopic procedures, especially the latter.
Sources of gas embolism: room air, carbon dioxide, carbon monoxide, and other gaseous products of vaporization or tissue combustion. The anesthesiologist is usually the first to identify the signs.
Signs of gas embolism. The surgeon should ask to be immediately alerted to any sudden fall in oxygen saturation, as well as to hypotension, hypercarbia, arrhythmias, tachypnea, or a “mill wheel” murmur. If any of these signs are detected and a gas embolism is suspected, stop the procedure and ventilate the patient with 100% oxygen.
Carbon dioxide is a soluble gas, so these emboli generally resolve rapidly. In contrast, room air emboli are more likely to be fatal.
Reduce the risk of air embolism by avoiding the Trendelenburg position and leaving the last dilator in the cervix until just before inserting the resectoscope.
Also limit repetitive removal and reinsertion of the resectoscope, as often occurs during myoma resection. By vaporizing rather than resecting myomas, it is possible to eliminate the need to continually remove fibroid chips. Preoperative GnRH agonists narrow venous sinuses and help prevent this complication.
Intracervical injection of dilute vasopressin prior to dilatation of the cervix creates vascular spasm and may help prevent gas from entering the circulation.
Complications from distention media
Excess absorption of distention media is one of the most frequent complications. Most surgeons use low-viscosity, sodium-free fluids for operative hysteroscopy, since fluids that contain electrolytes are incompatible with monopolar electrosurgical instruments. The use of 3% sorbitol, 1.5% glycine, or sorbitol-mannitol solutions can lead to dilutional hyponatremia and hypoosmolality.18 Although the vast majority of women quickly recover from these conditions, some cases of permanent morbidity and even death have been reported.19 The overall incidence of dilutional hyponatremia was 0.2% in 1993, according to the AAGL member survey.1
