Prevention and management of complications during Hysteroscopy

Diagnostic hysteroscopy is a safe procedure with few complications. Operative Hysteroscopy is associated with more complications depending on the complexity of the procedure. A series of 13,600 hysteroscopies reported an incidence of 0.13% complication for diagnostic and 0.28% for operative hysteroscopies (1). Complications tend to occur depending mostly when contraindications are ignored and when incorrect surgical techniques or instruments are used. Complications can occur, during hysteroscopy or post operatively.

Intraoperative complications

Uterine perforation

This is the most frequent complication during hysteroscopy, occurring at a rate of 14 per 1000 cases (2) The factors which predispose to perforation during diagnostic hysteroscopy are failure to recognise sharply anteverted or retroverted uterus, insertion of the telescope without clear vision, or a small uterine cavity. Simple perforation of uterus can be made with a dilator or hysteroscope. Perforation is suspected if dilator passes to a greater depth than expected. Perforation is recognized by visualising the loops of bowel with hysteroscope. This rarely causes damage to an intraabdominal organ and can be treated conservatively.

Hysteroscope should be passed under constant visual control. It is important to understand that a 30 telescope will show the cervical canal in an eccentric position unlike a 0 degree telescope which will show the canal in the centre of the monitor.

Complex perforations are made with forceps, scissors or the resectoscope. Scissors are Commonly used to resect the septae or synechiae. The chance of perforation is highest in Asherman’s syndrome because of the absence of anatomical landmark. This is the only condition when concomitant laparoscopy is mandatory to prevent or immediately detect perforation. Transillumination of the fundus allows an assistant to recognize when dissection is approaching the fundus before perforation occurs. It is easier to use smaller operating hysteroscope with semirigid scissors than resectoscope for synechiotomy.

A perforation rate of one in 100 has been reported during division of uterine septum (3). It is important to differentiate between a septate and bicornuate uterus by doing a laparoscopy before incising the septum. The septum should be divided in the centre. Frequent panoramic view at the level of internal os help in detecting the extent of septum incision. A close up view mislead the operator in over correction and perforation.

Perforation can occur during endometrial ablation if fundus and cornua are resected with loop electrode. Cornua of the uterus can be as thin as 4mm and improperly directed loop can perforate the uterus. It is safer to use a ball electrode to coagulate the fundus and cornua. Perforation can occur if ablation is attempted without clear vision, same area is resected more than once or the loop is activated and advanced instead of being withdrawn.

Perforation of the uterus during operative hysteroscopy is usually recognized easily because the intra uterine pressure drops and flow of distending fluid increase rapidly as the fluid enters the peritoneal cavity and previous clear vision is lost.

Once perforation is diagnosed the immediate goal is to asses the damaged area, control of blood loss and visualisation of surrounding structures to asses the damage. The most significant complication for the patient once perforation has occurred is damage to the surrounding visceral contents. The extent of damage is related to the instrument used during perforation. If the scissors perforate the uterine corpus, identification and visualisation of the injured area is usually minimal. when damage has occurred with electrocautery, injures can involve major blood vessels ureter, bladder and bowel (4,5,6).

Once the perforation is suspected, the diathermy is switched off and hysteroscope left in situ. Laparoscopy is performed and nature of defect is assesd. The bowel, ureter and great vessels must be inspected in detail to ensure that they have not been damaged.

Complications of distending media

Panoramic hysteroscopy requires uterine distension. The commonly used distending media are carbon dioxide and low viscosity fluids like saline or glycine. Carbon dioxide is commonly used for diagnostic hysteroscopy. It requires a special insufflator, which regulates carbon dioxide flow rates of around 100ml/min and pressure of 100mmHg.

Low viscosity fluids are the most frequently used. Normal saline or Ringer’s lactate is used when electrosurgery is not needed. During electrosurgery, non-electrolyte solution like 1.5% glycine, 3% sorbitol plus 0.5% mannitol or 5% mannitol is used. This fluid can intravasate depending on the pressure used to distend the cavity, the type of operation and the duration of procedure. When excessive intravasation of electrolyte solutions occurs pulmonary oedema may result. These situations can be easily managed with diuretics. When excessive vascular intravasation occurs with non-electrolyte solutions hypo-osmolarity and hyponatremia can result. If this condition is not recognized promptly and treated aggressively, cerebral oedema and herniation of the brain stem can cause death (7,8). Premenopausal women are 25 times more likely than men or post menopausal women to die or have permanent brain damage should hyponatremic encephalopathy occur (9). The immediate cause of death may be more a function of hypo osmolality than hyponatremia (8). Fluid over load of distending medium was recorded in 0.2 % of hysteroscopic procedures in a multicentric study (1) it is commonly seen in submucous myomas (type 1, 11) resection. The single most factors in preventing fluid over load is avoiding intrauterine pressure above 100-110 mmHg. It is essential that the inflow and outflow is measured at frequent intervals throughout the procedure. If the deficit rises above 1 litre, the operation should be rapidly completed if the deficit is in excess of 1500 –2000 ml the procedure should be abandoned, diuretics administered, bladder catheter inserted and urinary output measured. The patient should be observed both clinically and radiologically for signs of pulmonary oedema .If serum sodium concentration falls below 120 mmol, hypertonic saline (3%)may be infused at a rate to increase serum sodium by 1 m mol/L/h.

Prevention of fluid overload depends on recognition of risk factors, use of fluid management system, meticulous technique and newer technology. Conventional electrosurgical hysteroscopic instrumentation use monopolar current. These systems require electrolyte-free media because the electrolyte containing media disperse the current prematurely and render the device ineffective.

Now there are newer instruments, which can work, in normal saline. Versapoint is a bipolar system that conducts electric current between two electrodes that are in close proximity in isotonic saline. During vaporisation the generator increases the temperature around the electrode tip so as to keep a vapour pocket. Energy flows in to the tissue and creates desiccation. ERA sleeve and the OPERA star system is a modification of monopolar technology, which can be used, in isotonic media.

Primary Haemorrhage

Haemorrhage during or just after the procedure is the second most common complication of hysteroscopy and occurs in 2.5% of every 1000 cases (2). The major causes of primary haemorrhage during resection or ablation are operating on an intramural fibroid, resecting too deeply in the myometrium and resecting close to endocervix. The pseudo-capsule of deep intramural fibroids especially this situated lateral to uterine wall may lie close to uterine artery. There is considerable risk of injuring the artery when resecting or ablating in this area. Deep myometrial resections may involve a plexus of large vessels and produce significant bleeding.

If vision is obscured by haemorrhage the pressure of irrigating fluid is increased until vision is restored and individual bleeding vessels coagulated separately. If vision is still obscured by blood, the operation should be abandoned and Foleys catheter inserted into the cavity and inflated. It usually controls the bleeding and it can be removed after 6 hours. Vasopressin (20 U in 20 ml saline) may be injected in to cervix to inhibit bleeding from the lower uterine segment. If facilities are available for uterine artery embolization it can be tried before considering hysterectomy. Bleeding occurs in 0.2% to 1% of endometrial resection (10) and 2.2 % of submucous myoma resection (11).

Electrosurgical complications

Electrosurgical thermal effects during hysteroscopic surgery are more complex and not fully understood. It can occur by faulty insulation of electrodes, capacitative coupling, or by direct coupling. Thermal injury in the absence of uterine perforation has been reported after roller ball endometrial electrocoagulation (4).

Whenever thermal injury is suspected, diagnostic laparoscopy or laparotomy is necessary. First inspect the serosa of uterus to look for any blanched area, and if present a thorough inspection of the bowel is mandatory.

Gas Embolism

Air embolism is a rare but devastating complication of hysteroscopy. Brooks has reviewed 7 cases of air embolism with 5 fatalities (13). Prevention of air embolism relies on understanding the physiology and the risk factors associated with air embolism. Trendelenburg position, difficult cervical dilatation, and operative procedures seem to be risk factors. Trendelenburg position places the uterus above the heart and creates a venous vacuum with each diastolic relaxation, potentially sucking air through the open venous sinuses. The first clinically recognizable change in a patient with air embolism is a decrease in end–tidal CO2. This is followed by hypoxia, tachycardia, tachypnoea, hypotension, and then cardiovascular collapse with bradycardia, hypotension and subsequent asystole. Auscultation over the precordium reveals typical mill wheel murmur.
On confirmation of an air embolism, the following steps are undertaken:

	Remove hysteroscope to discontinue insufflation, make sure vagina is closed or occluded with a wet sponge.
	Turn patient to left side to elevate and keep gas in the right side of the heart, decreasing the chance of paradoxic embolus.
	Consider precordial thumps to break up air pocket.
	Administer intravenous bolus of normal saline.
	Consider echocardiography to identify and possibly aspirate gas from the right side of the heart.

Transfer the patient to an intensive care unit is mandatory because pulmonary oedema and adult respiratory distress syndrome are likely sequelae of air embolism.

Postoperative and late complications

Infection is rare after diagnostic hysteroscopy (12). The risk of infection after operative hysteroscopy is 0.8-2% (10,11). Most post operative infections are uncomplicated cystitis, endometritis, or parametritis, but more serious infections have been reported. The operation is better avoided in presence of STD, Vaginal discharge or recurrent acute PID. Prophylactic antibiotics may decrease the risk of postoperative infection.

Functional islands of viable endometrial tissue can persist after endometrial ablation. Recently Valle and Baggish surveyed 6 cases of endometrial cancer diagnosed 5 months to 5 years after endometrial ablation (14). Most of these patients had multiple risk factors, most notably endometrial hyperplasia. Other important risk factors were obesity, hypertension, diabetes, nulliparity, delayed menopause, chronic anovulation, and unopposed exogenous oestrogen Women with multiple risk factors for endometrial cancer should be counselled for hysterectomy. Patients should be followed up with transvaginal sonography to detect residual endometrium after endometrial ablation. Any abnormal bleeding must be investigated with hysteroscopy and directed biopsies.

Hematometra

This may occur due to intrauterine adhesion behind which there is active endometrium, which undergoes cyclical bleeding producing a small localised haematomata. Patients present with cyclical pain and may be diagnosed with TVS. Drainage may be performed by repeat hysteroscopy. postoperative hematometra has been reported to occur in 1-2% of all endometrial ablation (15).

Uterine rupture during pregnancy

Uterine rupture during pregnancy has been reported after operative hysteroscopic procedure like myoma resection, septum incision, and adhesiolysis (16). Precipitating events include mechanical or electrosurgical perforation.

Summary

With pre operative evaluation, meticulous technique, and vigilance for impending problems, complications of operative hysteroscopy are largely preventable. Fluid overload is the most serious complication. Methods and technique should be adapted to minimize fluid intravasation. As new operative tools become available, saline can be used for resectoscopic surgery. A hysteroscopic surgeon must be knowledgeable about risk factors of air embolism as well as its management. Mechanical complications, electrical injury, and infections can be reduced by proper selection of cases and good technique

Late complications result from either persistent endometrium after ablation or myometrial damage during surgery. Meticulous diagnostic assessment and preoperative consideration of risk factors remain the keys to minimizing late complications.

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