Anatomy of the Innervation of the Abdomen
Pain is an important indicator of abdominal pathology and the site and nature of the pain is an important indicator of the likely cause. Pain is also an inevitable consequence of operating in the abdomen. The major cause of post-operative pain is the trauma to the abdominal wall required to access the pathology of the peritoneal cavity, but pain may also originate from the abdominal organs (visceral pain) and the peritoneum. For many surgical procedures the advent of minimally invasive techniques has dramatically reduced the component of post-operative pain originating from the abdominal wall without necessarily impacting on the lesser visceral component. An array of local and regional anaesthetic techniques are used to control post-operative pain either as a sole method or as an opiate sparing adjunct to systemic analgesia. The technique used is a reflection of the type of abdominal surgery being performed and the site and size of the abdominal wound(s). However, it also reflects the expertise and preference of the anesthetist and surgeon involved.