Anterior (Transperitoneal) Approach to the Lumbar Spine

Indications

  • Fusing L5 to S1
  • Not for occasional user

Position

  • supine
  • prep & drape for 2 incisions
    • abdominal
    • anterior iliac crest bone graft
  • GA
  • urinary catheter
  • nasogastric tube
    • ileus is common

Landmarks

  • umbilicus
    • opposite L3-4 disc space
  • pubic symphysis

Incision

  • longitudinal midline incision
  • Start: xiphistenum
  • Curved to the LEFT around umbilicus
  • End: pubic symphysis

Internervous Plane

  • Abdominal muscles on each side
    • Segmentally supplied by branches from 7th to 12th intercostal nerves

Superficial Dissection

  • Deepen wound in line with incision
    • Fat
  • Rectus sheath
    • Incise longitudinally
    • Reveals 2 rectus muscles
    • Separate with fingers
  • Peritoneum
    • Pick up with pair of forceps & incise with knife
    • Extend incision watching for viscera, bladder

Deep Dissection

  • Balfour self retaining retractor
    • Retract viscera laterally
  • Put tables in Trendelenburg’s position of 30°
    • Carefully pack bowel cephalad
  • Infiltrate tissue over anterior surface of sacral promontory with a few millilitres of saline
    • Makes dissection easier
    • Helps identify presacral parasympathetic nerves
  • Ligate sacral artery
    • Runs down midline
  • Identify L5-S1 disc space
    • Palpate sharp angle
    • I.I
    • Lies below aorta bifurcation

Dangers

  • Presacral plexus of parasympathetic nerves
    • Retroejaculation & impotence
  • Vessels
    • Middle sacral artery
    • Aorta
    • IVC
  • Ureter