Complications of laparoscopy

Practical Training and Research in Gynecologic Endoscopy

A. G. Gordon
Honorary Consultant Gynaecologist, Princess Royal Hospital,
Saltshouse Road, Hull HU8 9HE
and
Consultant Gynaecologist, BUPA Hospital Hull & East Riding,
Lowfield road, Anlaby, Hull HU10 7AZ, United Kingdom

INTRODUCTION

Complications can occur with any form of surgery The prevalence is difficult to assess because there have been no national surveys since those carried out by the American Association of Gynecologic Laparoscopists in 1976 and the Royal College of Obstetricians and Gynaecologists in 1977. At that time laparoscopy was virtually confined to diagnostic procedures and sterilisation. Only occasional other minor operative procedures were performed. A very few centres had begun to treat ectopic pregnancies, divide adhesions and perform salpingostomy.

As operative laparoscopy becomes more widely accepted, new techniques are being developed and more surgeons are adopting this form of management, the complication rate can be expected to rise. The incidence of laparoscopic complications is 1.1% to 5.2% in minor procedures and 2.5% to 6% in major ones (Kane & Krejs, 1984). It is becoming increasingly evident that, in order to reduce the prevalence of complications, training programmes must include supervision at all levels of development and there must be a high degree of awareness of the potential risks of laparoscopic surgery.

Complications may be associated with:

The anaesthetic
The induction of pneumoperitoneum
Insertion of primary and secondary trocars
Thermal Instruments
Mechanical Instruments
Other associated conditions

1. THE ANAESTHETIC

Complications directly attributable to the general anaesthetic are no different from those which may occur when any other type of surgery is performed. Some features of laparoscopic surgery predispose to specific anaesthetic complications.

The use of a steep Trendelenburg position and the distension of the abdomen may both reduce excursion of the diaphragm. Carbon dioxide (CO2) can be absorbed particularly during prolonged operations. Monitoring by pulse oximetry, the use of endotracheal intubation and positive pressure assisted ventilation reduce the risk of hypercarbia to a minimum. If arrhythmia occurs the anaesthetist will be responsible for its management and is at liberty to instruct the surgeon to return the patient to the supine position, evacuate the pneumoperitoneum and discontinue the surgery.

Vasovagal reflex may produce shock and collapse especially if the anaesthetic is not deep enough. Again it may be prevented by efficient anaesthesia and should only be diagnosed when other causes of shock have been excluded.

Local anaesthesia may be used for tubal sterilisation and some other minor procedures. This may produce specific problems and complications:

1. Anxiety.

Anxiety may be prevented by administration of Diazepam 20 mg orally about one hour pre-operatively.

2. Vasovagal reaction.

This may be associated with bradycardia and, in more severe cases, cardiac arrest, convulsion and shock. The treatment should include:

Atropine 0.5 mg given intravenously (IV)
Oxygen given by endotracheal tube at a rate of 4-6 litres/minute
Adrenaline 0.5-1.0 ml of 1:100,000 solution given slowly IV
Respiratory and cardiac resuscitation.

3. Pain.

Pain may be prevented to some extent by the administration of non-steroidal anti-inflammatory drugs such as mefanimic acid, naprosene or fentanyl. It is prudent to have an anaesthetist available because about 2% of patients find the operation painful and consideration must be given to completing it under general anaesthesia (Gordon, 1984).

4. Allergic reactions and anaphylaxis.

Any local anaesthetic should be given initially as a small test dose to determine if an unsuspected hypersensitivity exists. Obviously if it does, no more medication should be administered. If a reaction occurs it will be characterised by agitation, flushing, palpitations, bronchospasm, pruritus and urticaria. The treatment will depend on the severity of the reaction and may include:

Adrenaline 0.5 mg (1:100,000 solution IVI or IMI)
Prednisolone 25 mg IVI
Theophylline 250 mg (10ml) given slowly IVI
Intravenous fluids
Oxygen

INDUCTION OF PNEUMOPERITONEUM

1. Extra-peritoneal gas insufflation

Failure to introduce the Veress' needle into the peritoneal cavity may produce extra-peritoneal emphysema. This occurs in about 2 per cent of cases. The diagnosis is made by palpation of crepitus caused by bubbles of CÓ2 under the skin.. If this is recognised early, the gas may be allowed to escape and the needle re-introduced through the same or another site.

If the complication is not recognised during the introduction of gas, the typical appearance of extra-peritoneal gas may be recognised when an attempt is made to introduce the telescope. It is always essential to view through the telescope during its insertion through its cannula. The typical spider-web appearance caused by pre-peritoneal insufflation will be seen when the telescope reaches the end of the cannula and further stripping of the peritoneum by the tip of the telescope avoided. The laparoscope should be withdrawn and attempts made to express the gas. The needle may then be re-introduced through the same or another site. Alternatively the trocar and cannula may be introduced by 'open laparoscopy'.

2. Mediastinal emphysema

Gas may extend from a correctly induced pneumoperitoneum into the mediastinum and create mediastinal emphysema. Extensive emphysema may cause cardiac embarrassment which will be diagnosed by the anaesthetist. There will be loss of dullness to percussion over the precordium. The laparoscopy must be abandoned and as much gas as possible evacuated. The patient must be kept under close observation until the gas has been absorbed.

3. Pneumothorax

Pneumothorax may result from insertion of the Veress' needle into the pleural cavity. Whenever a high site of insertion is chosen the needle should be directed away from the diaphragm and, as always, the standard protocol of aspiration and sounding tests employed.

Pneumothorax should be suspected if there is difficulty in ventilating the patient. There may be a contra-lateral mediastinal shift and increased tympanism over the affected area. The procedure should be abandoned and the gas allowed to escape. The patient should be kept under observation. Occasionally assisted ventilation and insertion of a pleural tube may be required.

4. Pneumo-omentum

The omentum is penetrated by the Veress' needle in about 2 per cent of cases. The misplacement should be recognised by the aspiration test and the position of the tip altered to free the needle. There will also be a raised insufflation pressure which should lead the surgeon to suspect an error in the position of the needle. The condition is usually innocuous unless and omental blood vessel is punctured.

5. Injury to gastro-intestinal tract

Certain conditions may predispose to injury by the Veress' needle. These include distension of the gastro-intestinal tract or adhesions of bowel to the abdominal wall.

Penetration of the stomach may occur when an upper abdominal site of insertion is chosen or the stomach is distended during induction of anaesthesia. Gastric distension may also occur if anaesthesia is maintained with a mask and should be suspected if there is upper abdominal distension or increased tympanism. In this case the stomach should be aspirated with a naso-gastric tube. The diagnosis of gastric perforation by the Veress' needle may be made when the patient belches gas. The laparoscope should be introduced and the stomach inspected carefully. Provided the stomach wall has not been torn, no surgical treatment is necessary but a broad spectrum antibiotic should be given. If the stomach has been torn, surgical repair either by laparotomy or laparoscopy is mandatory.

Aspiration following initial insertion of the needle should permit early recognition of perforation of the bowel but it is not fool-proof. Bowel penetration should be suspected if there is asymmetric abdominal distension, belching, passing of flatus or a faecal odour. The induction of pneumoperitoneum should be stopped and the needle re-sited to introduce the pneumoperitoneum correctly. The gastro-intestinal tract should be examined carefully for perforation. It is important that both sides of the bowel be examined as the exit wound may be larger than the entry wound. Faecal soiling demands immediate laparotomy and repair of the bowel. It is important to ensure that there has not been a through-and-through injury of a loop of bowel which is adherent to the peritoneum at the site of insertion. A simple needle penetration requires no treatment but the patient should be kept under observation and given broad spectrum antibiotics.

6. Bladder injury

Routine catheterisation of the bladder and proper siting of the needle should prevent bladder penetration. If pneumaturia is noted the needle should be partially withdrawn and the creation of pneumoperitoneum continued. The bladder peritoneum should be carefully inspected to ensure that no significant injury has been caused. The treatment of a simple puncture is conservative with postoperative bladder drainage.

7. Blood vessel injury

The Veress' needle may penetrate omental or mesenteric vessels or any of the major abdominal or pelvic arteries or veins. Minor vascular injuries involving the omental or mesenteric vessels are difficult to prevent as it is impossible to ensure that the omentum is not close to the abdominal wall during blind insertion of the insufflating needle. Injury may be suspected if blood returns up the open needle or if free blood is seen in the peritoneal cavity after insertion of the laparoscope. If blood returns up the needle and the patient's condition is stable, the site of injury may be investigated laparoscopically. The needle should be left in place and a 5mm laparoscope introduced through a suprapubic cannula. Minimal bleeding may usually be controlled by bipolar coagulation or a laparoscopic suture. Laparotomy is not usually necessary except in the case of injury to the superior mesenteric artery. Such injury requires repair by a vascular surgeon (Bassil et al, 1993)..

Injury to the major vessels may be prevented by lifting the abdominal wall, angling the needle towards the pelvis once the initial thrust through the fascia has been made and by inserting only as much of the needle as necessary. Thin patients and children are at particular risk of this injury.

Withdrawal of blood on aspiration following insertion of the needle should allow early detection of blood vessel injury. If injury to a vessel such as the aorta, inferior vena cava or common iliac vessel is suspected, the needle should be left place to mark the site of the injury and laparotomy performed through a mid-line incision. There is usually a large haematoma which obscures the site of the injury. The aorta should be compressed with a clamp or hand until a vascular surgeon arrives to perform definitive surgery.

Dramatic collapse may result from penetration of a major vessel but the bleeding may not be immediately evident if it is retro-peritoneal. The loose areolar tissue anterior to the aorta can allow accumulation of a considerable amount of blood before frank intra-abdominal bleeding is seen. A thorough search must be made to determine the extent of vessel damage. This includes retraction of bowel to expose the aorta above the pelvic brim which is the most common site of perforation. Failure to do so may result in continued bleeding and formation of a large haematoma leading to a second episode of shock some hours later

8. Gas embolism

Intravascular insufflation of gas may lead to gas embolism or even death. This can only happen if the penetration by the Veress' needle goes unrecognised and insufflation commences. It should be prevented by routine use of the aspiration test. The patient should be turned on to the left lateral position and, if immediate recovery does not take place, cardiac puncture performed to release the gas.

9. Puncture of liver or spleen

The liver or spleen may be punctured by the Veress' needle when a high insertion site is chosen. It may also occur in the presence of hepatomegaly or splenomegaly. The aspiration test and the high insufflation pressure will make it obvious that the needle is sited incorrectly in which case it should be withdrawn and re-sited.

10. Complications from the distension medium

Carbon dioxide (CO2) is the distension medium most commonly used for operative laparoscopy. Gas embolism is possible but uncommon because the gas is highly soluble and is reabsorbed so quickly that, even if there has been a moderate embolus, the circulatory changes return to normal within a few minutes and the patient recovers. Up to 400ml of gas may be intravasated without producing changes in the ECG.

Cardiac arrythmia may be due to excessive absorption of CO2. It is important to monitor the intra-abdominal pressure throughout the operation and to use an automatic pneumoflator for all but the simplest forms of surgery. This will cut out if the intra-abdominal pressure rises. Endotracheal intubation and positive pressure respiration will also help to prevent complications from CO2 insufflation.

Post-operative pain is common with CO2 insufflation due to peritoneal irritation which is a result of conversion of CO2 to carbonic acid. The chest pain may be confused with coronary heart disease and be treated inappropriately with anti-coagulants. This may produce a wound haematoma or intraperitoneal bleeding.

Nitrous oxide (N2O) has become popular with some laparoscopists because there are less side effects than with CO2. Anaesthetists can dispense with intubation and allow the patient to breath through a laryngeal mask. However, in modern laparoscopic practice, a diagnostic laparoscopy may develop into a complicated operative procedure. N2O supports combustion. Methane gas may be released into the peritoneal cavity following bowel injury. A high frequency monopolar current used during laparoscopic surgery may cause an explosion.

The main place for N2O is when laparoscopy is being performed under local anaesthesia in which case the pain factor becomes important. This is applicable to tubal sterilisation with clips, rings, or bipolar coagulation, but not to more advanced laparoscopic procedures.

INTRODUCTION OF TROCARS AND CANNULAE

Some of the most serious injuries that occur during laparoscopy are caused by the insertion of the trocars and cannulae. Insertion of the primary trocar and cannula is, of necessity, blind. The causation of injuries by the primary trocar are similar to those caused by the Veress' needle but the magnitude of the injury is greater.

The sites of the secondary portals of entry must be selected carefully and the insertion must always be made under visual control.

1. Injury to vessels in the abdominal wall

Superficial bleeding from the incision rarely gives rise to concern and always stops with application of pressure.

Bleeding from puncture of the deep inferior epigastric artery is more serious. The artery is at risk during the insertion of secondary trocars and cannulae. This may be prevented by transilluminating the abdominal wall before insertion in a thin patient or by visualising the artery laparoscopically as it runs lateral to the obliterated umbilical artery. The site of insertion can then be chosen by depressing the wall skin with the handle of the scalpel and noting its relationship to the vessels.

The diagnosis may be made by the sight of blood dripping into the pelvis from the trocar wound. Occasionally blood may actually be seen spurting across the abdominal cavity. Alternatively the immediate or delayed appearance of a large abdominal wall haematoma indicates injury to the deep inferior epigastric artery.

The treatment is usually simple. The trocar and cannula should be left in situ to act as a marker and also prevent the artery slipping away. A Foley catheter passed down the cannula and inflated may act as a compress and control the bleeding. Alternatively the incision should be enlarged to about 2 cm in length to expose the anterior rectus sheath. A round bodied needle should be inserted through the full thickness of the abdominal wall from the sheath to the peritoneum under laparoscopic control. The needle point should be brought out again to the surface of the rectus sheath and a knot tied firmly on the sheath. This is preferable to tying the knot on the skin which is painful and leaves an unsightly scar although it is acceptable to tie the knot over a gauze swab to prevent skin injury. It may be necessary to insert two sutures, one above and one below the site of bleeding.

Occasionally it may be necessary to open the wound wider to locate the bleeding artery. This should be reserved for those cases where there is profuse bleeding or primary laparoscopic suturing is ineffective.

2. Injury to an intra-abdominal vessel

Injury to minor blood vessels is usually self-limiting or can be controlled by bipolar electro-coagulation. Damage to major vessels is more serious than with a Verres' needle because of the size of the trocar tip and may result in profuse bleeding. Injury to omental vessels may compromise the vitality of a segment of bowel. Treatment of these injuries is by resuscitation, laparotomy, vascular repair or ligation and, where necessary, bowel resection and anastomosis with the assistance of the appropriate surgical colleague.

A small leak from the a major vein may not be immediately apparent. The intra-abdominal pressure of the pneumoperitoneum and the decreased venous pressure induced by the Trendelenburg position may temporarily control it. However, as soon as the intra-abdominal and venous pressures return to normal, the bleeding may recommence and produce a retro-peritoneal haematoma and shock.

It is essential therefore, at the completion of any laparoscopic procedure, but especially those involving the pelvic side wall, to inspect the course of the major vessels and look for a haematoma. This applies particularly to the treatment of endometriosis at this site. A small haematoma may be the only evidence of injury to a vein at the pelvic brim. Occasionally there may be a defect in the overlying peritoneum which indicates the site of entry of the trocar. It is essential to proceed to laparotomy to repair the vessel. A vascular surgeon should be consulted and the vessel compressed until the arrival of specialised assistance.

3. Injury to a hollow viscus

Injury to a hollow viscus may vary from superficial damage of the serosa to complete penetration into the lumen. If penetration has occurred the viscus may slip off the trocar, the trocar may remain within the lumen or, rarely, the trocar may pass right through the a loop of bowel which becomes impaled upon it. It is always important to inspect the bowel at the axis of insertion of the primary trocar and cannula to ensure that it has not been damaged. If the cannula remains within the bowel the injury will be obvious by the recognition of mucosal folds. A through and through injury may be missed and only become apparent by the sight of faecal soiling, a faecal smell when the pneumoperitoneum is released or the subsequent development of peritonitis.

Injury to the stomach or bowel are always serious. The management depends on the skill of the surgeon. The classical treatment is to perform laparotomy and suture the bowel in two layers. A skilled surgeon may perform the repair by laparoscopic suturing. The defect should be closed in two layers in such a way as to avoid stricture formation, there should be copious peritoneal irrigation and a drain should be inserted into the abdomen. Appropriate antibiotic therapy should be instituted.

It may not be possible to identify the site of injury by laparoscopy. In this case it is essential to perform laparotomy to find and treat the bowel injury. Failure to do this will result in the patient developing faecal peritonitis and becoming dangerously ill.

Bladder laceration may occur during mobilisation of the bladder in advanced pelvic surgery. It should be sutured in two layers using laparoscopic suturing technique and a Foley catheter inserted into the bladder.

4. Damage to other organs

Minor injuries to other organs are usually self-limiting. They should be inspected at the completion of the procedure. Peritoneal lavage must be carried out to remove blood and clot and ensure that the bleeding has stopped. A small puncture on the surface of the uterus may be treated with bipolar electro-coagulation if bleeding does not stop spontaneously.

Injuries to the liver and spleen are rare unless the organ is pathologically enlarged. Such injuries are more likely to occur in operations performed by general surgeons. Minor bleeding will stop spontaneously. Major haemorrhage requires immediate laparotomy.

THERMAL DAMAGE

Burns from electric current were one of the major causes of complications when monopolar tubal coagulation was the principle method of female sterilisation. The incidence of burns was dramatically reduced by the introduction of bipolar and thermal coagulation and mechanical devices to occlude the tubes.

Monopolar electric current passes into the patient's body from the electrode which may be forceps or a needle. The current passes into the patient's tissues at the point of contact and then must return to the generator via the return plate. This is usually placed on the patient's leg. The effect of the electric current will depend its power and the power density which, in turn depends on the area and duration of application. To obtain maximum tissue effect the area of application at the target organ is small. The current passes from that small area along the path of least resistance towards the return plate. In gynaecological surgery this pathway is usually over the surface of loops of bowel. The area of the return plate is large so the power density at its site of application to the skin is low. However on its return pathway the current may pass over a small area of contact between two organs. The power density at that point may be high. In this way a burn may occur outside the surgeon's visual field. Normally this does not happen and the current passes harmlessly to the dispersive plate.

Thermal injury to organs such as bowel may also result from leakage of current from the shaft of the instrument. This leakage may result from insufficient or faulty insulation or from capacitative coupling in which there is a build up of current in the shaft of the instrument because the normal escape route has been shut off. Current normally escapes from the metal cannula through the patient's anterior abdominal wall to the return plate. If a plastic cannula has been used this route is closed and the current may escape to bowel. If the contact point between instrument and bowel is small, the power density may be high and thermal injury will result.

Occasionally the monitoring system may not be properly earthed. If the current passes via an ECG electrode instead of to the return plate, the patient may suffer a skin burn because the ECG electrode is small and so the power density is high at this site. Alternatively, the current may pass along one of the ancillary instruments which, if not properly insulated, may produce a skin burn at the portal of entry or the surgeon may suffer a burn on the hands or face.

There is a danger of lateral heat spread with monopolar or bipolar current. It is important to ensure that no other organ is in contact with or near an organ to which electricity is being applied. Lateral spread may also be minimised by keeping the forceps blades close together. Build-up of thermal energy may be prevented by intermittent application of energy which, in effect, produces a pulsed current.

The bowel is the most commonly injured organ. The injury may range from minor blanching of the serosa to frank perforation. Perforation requires laparotomy, excision of the surrounding devitalised bowel and repair of the defect. If blanching is significant, laparotomy excision of the damaged tissue and surgical repair should be performed immediately. Failure to do so may result in delayed ischaemic necrosis at the site of the burn. Initially there may be few symptoms but commonly the patient will complain of feeling unwell and this feeling may not improve as quickly as usual. It should be realised that any patient who feels unwell on the day after surgery and whose condition does not improve over the next few hours, may have an unsuspected injury to the bowel. The unwary physician may allow the patient to return home. The insidious development of vague abdominal symptoms, discomfort, anorexia and possibly pyrexia may not be recognised by her medical attendants. A faecal fistula may not form for 48-72 hours. Fecal peritonitis slowly develops and the patient may become seriously ill over a period of days before re-admission is requested. Radiology followed by laparotomy reveals the desperate situation. Laparotomy is followed by repair of the bowel or, more often, colostomy and drainage of the peritoneum. A prolonged period of serious illness may follow.

It must always be remembered that electric current is potentially dangerous and all the safety rules for its use must be strictly obeyed.

INJURY FROM MECHANICAL INSTRUMENTS

The main injuries caused by scissors or forceps are to a blood vessels. Bleeding will be immediately obvious and should be controlled by bipolar or thermocoagulation or by suturing. Direct inadvertent injury to other organs by mechanical instruments may result from careless or clumsy use.

OTHER COMPLICATIONS

A number of other complications may result from laparoscopy.

1. Cervical laceration

It is common for the cervical tenaculum to cause a laceration of the anterior lip of cervix. The cervix should always be inspected at the end of the procedure. The bleeding may usually be controlled by pressure from sponge forceps but occasionally requires suturing.

2. Uterine perforation

Uterine perforation may be caused by the manipulating cannula or during dilatation and curettage. The perforation should always be inspected with the laparoscope during and at the end of the procedure. Bleeding is usually slight and the complication does not usually require treatment.

3. Shoulder pain

Carbon dioxide is converted to carbonic acid when it is in solution with body fluids. This is irritant to the peritoneum. Diaphragmatic peritoneal irritation produces pain which is referred to the shoulder by the phrenic nerve. This pain may be confused with cardiac pain by the unwary physician and treated inappropriately.

4. Pelvic inflammatory disease

There is a small risk of producing or exacerbating a pelvic infection by uterine cannulation and chromopertubation. Post-operative pelvic infection is probably less common after laparoscopic surgery than after laparotomy.

5. Omental and Richter's herniation

If the primary cannula is withdrawn with its valve closed, it is possible to draw a piece of omentum into the umbilical wound by the negative pressure so produced. This is usually recognised immediately and the omentum is easily replaced. Herniation may occur some hours after the operation. It is usually easy to replace it under local anaesthesia and resuture the wound.

Herniation does not occur commonly with 5mm skin incisions. Incisions greater than 7mm should be sutured in layers to prevent formation of a Richter's hernia.

6. Injuries from the operating table

Care must always be taken in positioning the patient on the operating table. Injury can be caused to the nerves of the leg and to the hip and sacro-iliac joints. Compression of the leg veins may predispose to venous thrombosis. The brachial plexus may be injured if the arm is abducted. The hands may be caught in moving parts of the table.

It is important that the patient touches no metallic parts of the table if electric energy is being used.

7. Foreign bodies

Occassionally tubal clips or rings or parts of instruments such as saphire laser tips may be inadvertently dropped and lost in the peritoneal cavity. They should be removed if they are easily found but there have been no reports of long term complications from such foreign bodies.

REFERENCES

Bassil S, Nisolle M, Donnez J (1993). Complications of endoscopic surgery in gynaecology. Gynaecological Endoscopy, 2: 199-209
Kane MG, Krejs GL (1984). Complications of diagnostic laparoscopy in Dallas. Gastrointestinal Endoscopy, 30: 237-240