Expansion
Midline through the linea alba, gridiron at McBurney's point, Kocher for the gallbladder, Pfannenstiel for the pelvis
Expansion
- Midline - through the linea alba. Avascular, crosses no nerves, quick, and extendable; but heals less strongly and has the highest incisional hernia rate
- Paramedian - lateral to the midline, through the rectus sheath; largely abandoned
- Gridiron (McBurney) - at right angles to the umbilicus-to-anterior-superior-iliac-spine line at McBurney’s point. Each muscle layer is split along its own fibres, preserving nerves and giving excellent strength
- Lanz - a more transverse, cosmetically superior version of the gridiron
- Kocher (subcostal) - parallel to and about 2 cm below the right costal margin, for open cholecystectomy; divides the lower intercostal nerves and rectus
- Pfannenstiel - transverse suprapubic, through skin and rectus sheath with the rectus muscles retracted laterally rather than divided; the standard for caesarean section
The theme running through them all is that splitting structures along their fibres, and preserving segmental nerves, produces less pain and a stronger repair than dividing them.