Complications of hysteroscopy
A. G. Gordon
Honorary Consultant Gynaecologist, Princess Royal Hospital,
Saltshouse Road, Hull HU8 9HE
Consultant Gynaecologist, BUPA Hospital Hull & East Riding,
Lowfield road, Anlaby, Hull HU10 7AZ, United Kingdom
Complications may occur in diagnostic or operative hysteroscopy. The complication rate in diagnostic hysteroscopy is low and was estimated by Lindemann (1989) to be 0.012% . Complications from operative hysteroscopy are more common and potentially more serious. They may result from (Taylor & Gordon, 1994):
- Positioning the patient
- The distension media
- The surgery:
- Uterine perforation
- Delayed complications:
- Adhesion formation
- Failure of resolution of the presenting symptoms
The risks to the patient from the anaesthetic are similar to those from any other operation. The complications which are specific to hysteroscopic surgery and come into the purview of the anaesthetist are those which may present as shock resulting from uterine perforation or injury to a major vessel or from fluid overload. In these cases the anaesthetist may be the first to recognise the onset of danger and may recommend that the surgeon discontinue the procedure and return the patient to the supine position the better to institute appropriate treatment.
POSITIONING THE PATIENT
Incorrect positioning of the patient may result in:
- Nerve injuries
- Back injuries
- Damage to soft tissues
- Deep venous thrombosis (DVT)
1. Nerve Injuries
The degree of Trelendenberg tilt required for hysteroscopic surgery is less than that for operative laparoscopy. Brachial plexus injury may result from incorrectly placed shoulder restraints or from leaving the patient's arm abducted on an arm board. A non-slip mattress is preferable to restraints that compress the patient's shoulders. Injury can result from 15 minutes in a faulty position. The anaesthetist and surgeon should ensure that the patient is positioned properly.
Pressure on the peroneal nerve by lithotomy stirrups may result in paraesthesia and foot drop. The surgeon should ensure that, if lithotomy poles are used, the legs are adequately padded. Supports which hold the leg in a padded gutter are preferable.
Should injury occur, the advice of a neurologist should be sought immediately.
2. Back injuries.
The anaesthetised patient is defenceless against traction injury to the lumbar spine. The legs should always be lifted simultaneously and kept together until they are at the appropriate height when they should be abducted gently and placed in the supports. They should never be over-abducted as this can lead to damage to the sacro-iliac joints.
3. Damage to soft tissues.
It is the responsibility of the surgeon to ensure that there is no injury from moving parts of the table to the patient's soft tissues or hands. The surgeon should also ensure that no part of the patient is in contact with metal parts of the table because these can act as return plates for electrical energy and burns can occur at the point of contact.
4. Deep venous thrombosis.
Deep venous thrombosis can result from prolonged compression of the calves by the leg supports. The surgeon should ensure that the type of support is appropriate and well padded. If DVT is suspected the advice of a physician should be sought and appropriate anticoagulant therapy instituted.
THE DISTENSION MEDIA
Complications produced by the distension media are specific to hysteroscopic surgery. It is essential that all the operating room staff are cognisant of the side effects of the distension media and that responsibility for accountancy of fluid media is placed on a designated member of staff.
The nature of the complications depend on the type of medium in use. The medium may be carbon dioxide (CO2) in the case diagnostic hysteroscopy or fluid in both diagnostic and operative procedures. The fluid may be of high or low molecular weight. If excessive amounts of distension media are absorbed the following complications may occur:
1. Carbon dioxide.
Cardiac arrhythmia may occur with diagnostic hysteroscopy. The complication should be extremely rare if the correct insufflator is used. The hysteroflator delivers CO2 at a rate of not more than 100ml per minute whereas the laparoflator can deliver 1-6 litres in the same time. A laparoflater should NEVER be used for hysteroscopy. It is rare for CÓ2 to produce any side effects if gas embolism of less than 400ml occurs.
2. High molecular weight fluids.
Dextran is popular in some countries for both diagnostic and operative hysteroscopy when mechanical instruments are used. It may produce an anaphylactic reaction, adult onset respiratory distress syndrome (ARDS) or pulmonary oedema. Anaphylaxis should be treated by the administration of oxygen, antihistamines, glucocorticoids and intravenous fluids. Adult onset RDS requires the administration of glucocorticoids, oxygen and, occasionally, assisted respiration.
3. Low molecular weight fluids.
Saline may be used with the laser but only non-electrolytic fluids should be used with electrosurgery because of the risk of producing burns to other organs. All low molecular weight fluids may produce fluid overload. Accountancy of fluid input and output is mandatory in any hysteroscopic procedure. The severity and management of fluid overload depends on the nature of the medium in use.
Saline overload produces a simple hypervolaemic state which may be treated by insertion of a central venous line, administration of a diuretic, oxygen and, if necessary, cardiac stimulants. A blood pressure cuff may be applied to each limb in rotation to occlude venous return which, in effect, performs a bloodless phlebotomy.
Overload with sorbitol may produce hypoglycaemia in the diabetic patient, haemolysis or signs of hyper-volaemia. Hypoglycaemia should be treated with administration of glucose, measurement of blood sugar levels and restoration of euglycaemia.
Overload with glycine may produce nausea and vertigo, hypo-natraemia, transient hypertension followed by hypotension associated with confusion and disorientation. Excessive overload may produce elevated blood ammonium levels leading to encephalopathy and, rarely, death. Hyponatraemia should be treated with administration of diuretics and hypertonic saline solution combined with monitoring of serum electrolyte levels until normality has been restored. Encephalopathy requires haemodialysis to be performed.
These complications usually occur in the immediate post-operative period. The surgeon and/or anaesthetist have the responsibility to begin resuscitative procedures and seek appropriate advice and help from their colleagues in internal medicine. If such complications should occur during the procedure, surgery must be abandoned forthwith. Prevention may be accomplished by:
- Using appropriate distension media and delivery systems
- Keeping operating times to a minimum
- Avoiding entering the vascular channels
- Keeping fluid pressures below 80mmHg and gas pressures below 100mmHg.
- Meticulous accountancy of fluid balance. The procedure must be abandoned if the deficit rises to 2 litres or there is evidence of venous congestion..
Complications of surgery may arise during the operation or be delayed. Intra-operative complications include uterine perforation and haemorrhage. Delayed complications include infection, discharge and adhesion formation.
1. Uterine Perforation
The incidence of perforation is about 0.8% (Hill et al, 1992). In the British Mistletoe study perforation occurred in 0.64% and 0.65% of cases respectively with roller ball and laser but in 1.29% and 2.47% of cases when roller ball and loop or loop alone were used (Maresh 1996). The uterus may be perforated by a dilator, the hysteroscope or a surgical instrument. The management will depend on the size, method and site of the perforation, whether there is risk of injury to another organ and whether or not concomitant observation with a laparoscope was being performed.
Simple perforation may be made with a cervical dilator or with the hysteroscope. Perforation should be suspected if the dilator passes to a depth greater than the length of the uterine cavity. Perforation with the hysteroscope should be avoided by always introducing the telescope under direct visual control. Simple perforation rarely causes any further damage and may be treated conservatively by observation and appropriate broad spectrum antibiotics. Laparoscopy may be considered to exclude bleeding.
Complex perforation may be made with mechanical, electrical or laser instruments, It is unusual for perforation with scissors to cause injury to other organs although this may occur when dividing adhesions in cases of extensive Asherman's syndrome. Hysteroscopy in these cases should always be accompanied by laparoscopy to recognise impending or occult perforation.
Complex perforation caused by electrosurgical instruments or laser maybe associated with thermal injury to adjacent structures including bowel or large vessels. Laser may produce thermal injury at a distance from the site of the perforation because, once the myometrium has been breached, it will vaporise the next surface in its path. Displacement of bowel from he pelvis does not protect it from laser burns. If perforation is suspected the energy source should be switched off and the hysteroscope left in situ unless laparoscopic monitoring has been in progress in which case the telescope can be withdrawn. If the perforation has been caused by an electrosurgical instrument and concomitant monitoring has been performed, laparoscopic examination to exclude bowel injury may be all that is necessary. However in the majority of cases of electrical injury, and in all cases where laser has been used, laparotomy and detailed examination of the bowel, pelvic blood vessels and aorta is mandatory.
The prevalence of haemorrhage depends on the form of energy used for ablation. With loop and roller ball or loop alone the incidence is 2.57% and 3.53% respectively whereas with laser or roller ball it is 1.17% and 0.97% (Maresh 1996).
Intrauterine bleeding occurring during the procedure should be immediately obvious and can usually be controlled by spot electrocoagulation. If coagulation fails to control the bleeding, the procedure may have to be abandoned and tamponade performed by inserting a Foley catheter and distending the balloon. The catheter should be left in situ for a few hours after which the bleeding nearly always stops.
Occasionally these simple measures fail to control haemorrhage. This may occur if resection has been carried out too deep into the myometrium and a plexus of vessels opened. In this case hysterectomy, ligation or ultrasound guided embolization of the anterior branches of the internal iliac arteries may be necessary.
Less significant bleeding may be caused by tearing of the cervix with the tenaculum or uterine perforation. Lateral tears of the cervix may produce significant bleeding and may also lead to excessive absorption of the distention medium.
LATE ONSET COMPLICATIONS
Acute pelvic inflammatory disease is rare following hysteroscopic surgery. This may be prevented by prophylactic antibiotics. The diagnosis is made by the presentation of the classic symptoms and signs and treatment should be by appropriate antibiotics following culture of vaginal swabs and blood.
2. Vaginal Discharge
Vaginal discharge is common after any ablative procedure and is usually self limiting.
3. Adhesion Formation
Intrauterine adhesions are common especially after myomectomy when two fibroids are situated on opposing uterine walls. In this case the myomectomy is better performed in stages to prevent adhesion formation. An intrauterine device and administration of oestrogen and progestogen therapy may also help prevent adhesion formation following resection, adhesiolysis or division of a septum.
FAILURE OF RESOLUTION OF THE PRESENTING SYMPTOMS
The procedure may fail to cure the presenting symptoms. This may be because of poor patient selection or failure of the surgery.
Approximately 15% of patients have an early pregnancy loss following septum resection (Taylor & Gordon, 1993). There is also greater risk of third stage complications.
Myomectomy for menorrhagia or infertility gives disappointing results. About 20% have no immediate improvement and 80% fail to conceive.
Endometrial ablation produces amenorrhoea in about 30% of cases and satisfactory improvement in about another 50%. Ten per cent will require further surgery which may be a repeat ablation or hysterectomy.
Adhesiolysis for Asherman's syndrome is only curative in about 30-40% of cases.
- Hill D, Maher P, Wood C et al (1992). Complications of operative hysteroscopy. Endoscopy, 1, 185-189
- Lindemann H-J. Complications of Hysteroscopy (1986). Presented to European Society of Hysteroscopy, Antwerp
- Taylor PJ, Gordon AG (1994) Practical Hysteroscopy. Blackwell Scientific Publications,Oxford. pp 89-98