Safe Surgery for the New Millennium

For almost a century electro surgery has been in widespread use by surgeons to perform many types of operations. The technique works well and its basic principle has hardly changed in decades despite the introduction of modern electronics. However there are a number of inherent dangers, which occasionally result in unexpected injury, or even death of patients during quite routine operations. Such problems have become more numerous with the advent of keyhole surgery. The dangers of electro surgery have always been known of, though not often publicised, and paradoxically a much safer approach has for some time been known. So what exactly are these dangers, and why have the injuries (and even deaths) been allowed to continue until now, when there has apparently been a solution at hand? To understand the answer to this we must first understand a little about how electro surgery works and how it is used.

Electro surgery allows both cutting and coagulating of tissue by passing a high frequency, high voltage electric current through the tissue being operated on, from a hand held tool - i.e. an electric scalpel, but much more versatile. The high power density at the point of contact causes local heating and vaporisation of tissue. It can be used in an enormous variety of procedures from organ transplants to delicate opthalmics. There are two fundamentally different methods of deploying electro surgery known as Monopolar and Bipolar.

Monopolar is the most commonly used technique. Here power is delivered from a single hand held electrode and current passes through the body of the patient to a return electrode some distance form the surgical site. This return electrode usually takes the form of a foil plate tied or adhered to a fleshy part of the patient. This method achieves good cutting and coagulating performance but at the expense of some fundamental safety problems plus the inconvenience (and cost) of the separate return electrode (or plate).

For monopolar electro surgery to work safely and avoid unintended burns away from the surgical site, the current from the hand piece must disperse through out the body of the patient and there must be only a low current density at the return electrode.

If the return electrode is not attached properly burns may occur 'at the wrong end'! Modern machines have a plethora of monitoring circuits to try and prevent this occurring.

Another danger is from 'leakage currents'. For safe operation all the current must flow only between the hand-piece and return electrode. However if the patient comes directly into contact with other metal objects such as the operating table its self or equipment inserted in the body (as is the case during the keyhole surgery), there is a risk of setting up a leakage return path along which current can flow. This can also cause unwanted burns-the most alarming of which can be internal and go unnoticed until nasty side effects appear. Again modern machines have tried to get around this problem with ever more complicated and expensive monitoring devices. All these safety problems can be avoided by taking a different approach known as 'Bipolar'.

Here current is passed from one electrode to another in very close proximity (both built into the same hand-piece) through the tissue to be cut or coagulated. This method is fundamentally much safer and requires far less power than the monopolar technique, since the current is only passed across the tissue area being worked upon and does not have to pass through the bulk of the patient's body.

This method virtually eliminates all the dangers associated with the monopolar surgery. However until recently there has always been one big obstacle to its widespread use. It has only been really effective in a few coagulating procedures, not requiring cutting. The tissue cutting performance of a bipolar machine has always been considered far inferior compared to that of a monopolar machine. It has even been thought a bipolar machine could never achieve the same performance of a monopolar machine hence the universal acceptance of the potentially more dangerous monopolar method. Cynically, one could suggest it has been in the interests of manufacturers not to invest in developing bipolar surgery as a multi-million pound industry in the disposable return electrodes and associated safety devices would be lost!

But now a bipolar machine has been produced capable of performing all the techniques hitherto only the domain of more powerful monopolar machines. This has been achieved by gathering detailed information as to what exactly occurs during the use of electro surgery, using sophisticated data collecting equipment, then designing a new combined package of machine and hand tools. Performance has been spectacular and the new machines are now in daily use in St. James's and General Hospitals Leeds. Surgeon Mr. Simon Kay said "I would never use any thing else", " It takes care of all my needs, its ability to combine cutting and coagulation with little or no tissue damage is excellent". He recently performed a delicate pioneering operation to rebuild a smashed hand using such machines.

By no longer requiring the disposable return electrodes, UK hospitals are set to save an average £35,000 a year. The age-old return electrode burn problem is eliminated. A bipolar machine only need deliver a quarter of the electrical power to the patient compared to that of a monopolar machine, further reducing any risk.