Editing Incisions

Incisions



Midline

* Linea alba most easily found above the umbilicus, where it is wider
* Forceful lateral retraction of skin edges leads to splitting of the subcutaneous tissues, generally leading to linea alba
* Hard to find linea alba below umbilicus
* May see pyrimidalis fibres inferiorly
* Careful of bladder which lies between rectus and peritoneum
* Patent urachus can be divided with impunity

Paramedian incision

* Incise anterior rectus sheath vertically along entire incision
* Free rectus abdominis from sheath (dividing any tendinous intersections) and retract laterally (to preserve nerve supply, which enters laterally)
* Beware of deep IE artery
* Incise tough posterior sheath and transversalis fascia and peritoneum

Rectus split incision

* Same as paramedian, but rectus is not retracted, which means the section of it medial to the incision is denervated

Pararectus

* Vertical incision along lateral border of rectus, which is retracted medially

Transrectus

* Splits rectus fibres vertically

Transverse upper and lower incisions

* Option in children, as you maximise the length of the incision, since their abdomens are shorter
* Transecting the rectus sheath and muscle transversely causes little damage to its innervation since innervation is segmental - usually only get one or two nerves
* Lateral abdo wall muscles usually heal without weakness

Pfannenstiel

* Gently curving, 2-5cm superior to pubis
* Through fascia - incise
* Anterior rectus sheath are exposed and transected, dissecting away the sheath from adherent rectus superiorly and inferiorly
* Retract muscles laterally to reveal transversalis fascia
* Open peritoneum in midline, aware of bladder
* Iliohypogastric nerve is also at risk

Lanz

* Sometimes described for open appendicectomy, but can be transposed to left side for colonic resections

Kocher

* From 2-5cm inferior to xiphoid process, approximately 3cm inferior and parallel to costal margin (don't go too close or will need to include periosteum in closure)
* Can be extended bilaterally to form a chevron/rooftop/double Kocher (probably will need to take down falciform ligament and ligamentum teres)
* Divide anterior rectus sheath (beware superior epigastric artery, which should be ligated), rectus muscle, lateral abdo wall muscles are all divided along the same oblique line
* Peritoneum incised and opened
* Beware larger 9th thoracic nerve laterally - should be preserved. Smaller 8th thoracic nerve can be sacrificed.

McBurney

* Perpendicular to a line that connects ASIS to umbilicus
* If transverse, it is a Rockey-Davis incision
* If extended laterally for more exposure of caecum, called Rutherford Morrison incision
* Layers
** Scarpa's fascia - can be well-developed in young people and masquerade as EO
** EO: split obliquely. No muscle fibres should be seen
** IO with muscle fibres crossing at right angles to the split EO aponeurosis. 
** Transversus: transversely-running fibres (can masquerade as peritoneum)
** Peritoneum
* Avoid injury to rectus and innervation
* Beware of iliohypogastric nerve which should be protected


In super-obese patients, a lower midline incision can be prone to infection due to apron. Sometimes the upper midline incision gives reasonable access to lower abdominal structures, due to the degree of drape in these patients. 
[[Category:Operating theatre]]