HEURISTICS

This issue contains nine articles about heuristics. The word ‘heuristic’ is derived from the Greek word ‘heuriskein’ meaning ‘to discover’. It describes a type of informal learning that is derived from experience or intelligent guesswork. It is sometimes encapsulated by the terms ‘trial-by-error learning’, ‘mental short cuts’, and ‘using a rule-of-thumb’. Experienced surgeons inevitably develop heuristics without being conscious of their actions. They may relate to the way that retractors are used to display and secure an operative field, how you move your feet to obtain a better angle or a technique for inserting a stapling device into a constrained space. It is a fairly general term and, as this issue of the Journal shows, can be applied to many areas of surgical endeavour. The article by Patkin is a good place to start reading about heuristics.1 Patkin has been a pioneer in the field of surgical ergonomics, and in this article, he outlines some of the basic principles that underpin sound surgical techniques. This type of information is priceless. It should be required reading for surgical trainees (Fig. 1). You can find a full account of Patkin’s work at http:// www.mpatkin.org (cited 29 Sep 2008). One of the topics covered is the influence of the ‘internal precision grip’ on instrument design. First, the length of the handle must be longer than the distance between the tip of the curved index finger and the hypothenar eminence; the handle must be thick enough to enable a firm grip, with more than half of the handle circumference being enclosed to avoid slipping and the diameter of the handle should be enough to ‘almost separate the pulps of the finger tips when these are deformed and splayed by mild pressure’. A distinctive feature of the internal precision grip is ‘the amount of rotation that can be applied to a cylindrical handle by attempting to rub the thumb and index finger against one another’. These and other insights provide us with a portal into a neglected aspect of surgical technique. Patkin’s article reminds me of Henry’s book Extensile Exposure.2 Extensile exposure implies an incision that can be extended to deal with unexpected problems. Or, in Henry’s words: ‘Exposure that will vie effectively with the ‘‘great arsenal of chance’’ must be a match for every shift, and therefore have a range, extensile, like the tongue of the chameleon, to reach where it requires’. Henry drew attention to the ‘stripping angle’ between muscle and bone and the use of muscle mobility to define lines of approach to joints and vessels. But that book was mostly about applied anatomy in the limbs, and much of it is now outdated in both style and content. Nevertheless, it is still a profitable read – if you can get your hands on a copy.