Q2How is the patient positioned and the incision placed for the anterolateral approach?▸
Left side up (aorta side; IVC is fragile)
Break table centering at level of interest
Incision from 12th rib posterior half to rectus lateral border, centred at target VB
Q3Describe the dissection of the anterolateral/retroperitoneal approach.▸
Split EOM; divide IOM in line with incision
Split transversus abdominus and enter preperitoneal plane
Excise distal 5cm of 12th rib for better exposure
Elevate peritoneum from psoas fascia (ureter to anterior with peritoneum); follow psoas to VB AL border
Ligate segmental lumbar artery of concerned level close to aorta + iliolumbar vein
Q4What are the risks of the anterolateral/retroperitoneal approach?▸
Genitofemoral nerve
Sympathetic chain --> CPRS
Superior hypogastric plexus --> retrograde ejaculation
Q5Which spinal levels can be approached anteriorly, and what are the level-specific caveats?▸
Anterior approach for infection; otherwise more posterior
Anterior OK for C-T1 and T4-T11
T12-L1: at the diaphragm insertion --> diaphragm needs to be cut, approach still possible
L2-L4 anterior OK
L4-5: level of the bifurcation of the aorta
L5: must face both iliac vessels --> disc still possible, never corpectomy
Q6How is the skin incision planned for the left sided thoracolumbar junction approach?▸
Centred over fracture vertebra over a rib, from posterior proximal 2 levels above
Rib selected should be 2 levels above the fractured vertebra (rib curves down)
Q7Describe the initial exposure for the left thoracolumbar junction approach.▸
Chest muscles overlying rib and abdominal muscle distal to costal cartilage incised with cautery; retract lat dorsi posteriorly
Subperiosteal dissection of rib then rib resection (beware NV bundle at caudal edge)
Incise parietal pleura
Split the three muscle layers of the abdominal wall anteriorly and expose retroperitoneal cavity
Q8How are the diaphragm and spine exposed in the thoracolumbar approach?▸
Sweep peritoneum off inferior surface of diaphragm; take down to spine leaving 1cm margin for later attachment (access T12/L1)
Cut diaphragm at the periphery to avoid denervation
Lung retracted anteriorly (one lung ventilation) to expose spine
Open parietal pleura longitudinally over fracture level: begin dissection at the hills (IVD) to avoid segmental vessels at the valleys
Ligate segmental vessels; subperiosteal dissection to ALL with protection of great vessels
Q9Compare pin fixation and the horseshoe headrest for prone positioning.▸
Pin fixation device: rigid, no facial pressure; but pin wound complications and intraop loosening
Horseshoe head set (headrest): non-invasive, easy adjustment; but less rigid, intraop displacement and facial pressure (sore, glaucoma, nasal cartilage necrosis)
Q10What equipment is used for prone positioning and what deformity does each produce?▸
OSI spine table
Four poster (iliac and thigh support) - lordosis
Wilson frame (chest to pelvis pad support) - kyphosis
Q11Why is reverse Trendelenburg used in prone spine surgery?▸
Reduces facial and periorbital oedema
Reduces venous bleeding
Q12How should the trunk and limbs be positioned?▸
Free abdomen; free nipples and genitalia
+/- adhesive strap to pull shoulders down for CS imaging
Arms positioned, knee flexion, pad bony prominences