OrthoNet

Lumbar spine - anterolateral approach

* position - semilateral at 45 deg supported with sandbag with L side up (aortic side vs. caval side)

* incision
- oblique flank incision from post. 1/2 of 12th rib toward lateral border of rectus abdominis about midway btw umbilicus & pubic symphysis

* no internervous plane

* dissection
- expose aponeurosis of ext. oblique
- divide in line of fibers
- divide int. oblique & transversus in line with skin incision
- expose retroperitoneal space/fat
- using blunt dissection, develop plane btw retroperitoneal fat & fascia overlying psoas
- retract peritoneal cavity med.
- ureter taken with peritoneal contents (attached loosely to peritoneum)
- identify aorta, cava & lumbar vertebral bodies
- place needle in involved discs –> xray

* dangers
- sympathetic chain - lies on lateral aspect of vert. body on med. aspect of psoas
- genitofemoral n. - lies on ant. med. surface of psoas
- segmental lumbar art. & veins - must be tied to prevent bleeding
- vena cava - avoid vigorous retraction
- aorta
- ureter
> runs in med. aspect of field btw peritoneum & psoas
> usu falls forward with peritoneum