Editing Sentinel lymph node biopsy


== '''Goal:''' ==

* To stage the axilla

== '''Principles:''' ==

* Dual localisation
* Aim for 1-3 nodes

== '''Pitfalls:''' ==

* Inadequate nodal harvest
* Taking more nodes than is necessary

== '''SLNB localisation techniques''' ==

* '''<sup>99m</sup>Tc-labeled sulphur colloid combined with intra-op gamma probe'''
** Considered safe in pregnancy
** <24 hours pre-op
* '''Blue dye - 3-5mL'''
** Can use either '''patent blue/isosulfan blue''' (50mg in 2mL, diluted up to 5mL''';''' 0.16-1.1% anaphylaxis) or '''methylene blue''' (5mg in 5mL sterile water - can also be given as a last resort in septic shock - can cause skin necrosis with intra-dermal injection, lower rate of anaphylaxis)
** Can be injected subareolar, subdermal or peri-tumoural (not intradermally as it will cause a tattoo, and not into the tumour itself)
*** If injected peri-tumoural, 70% of patients have axillary drainage, 20% have drainage to both axilla and internal mammary basin, 2-3% to internal mammary basin alone, and 8% do not show drainage to regional nodal basin
*** If injected subareolar, virtually all drainage is to the axilla
** Not safe in pregnancy due to risk of anaphylaxis (1/1000)
** If significant hypotension occurs, usually abandon the procedure, support the patient and plan subsequent surgery without blue dye

== '''Technique''' ==

* TT, GA, prep and drape taking care of hookwire, IV Abx, TEDs, incision marked on breast, blue dye
* Supine, ipsilateral arm out, myself standing medial on ipsilateral side
* '''SLNB'''
** Small axillary incision at inferior border of hair-bearing skin, somewhat localised using Geiger counter
** Deepen incision into axillary fat towards node, using diathermy - assistant with Adson's, then cat's paws, then Langenbeck's; instruct assistant to hold steady as they won't be able to see
** Look for blue lymphatic channels and dissect/ligate carefully; use Geiger intermittently
** Expect to see blue node with higher signal
** Babcock grasper to remove from wound, dissect down to pedicle, remove
** Ideally 2-3 nodes (avoid additional adjuvant therapy/clearance)
** Take formal count using Geiger counter, send to pathology
*** Take background count in axilla, if >10% of the node you removed, may need to chase more nodes
** Palpate for other nodes in axilla
** If unable to find nodes, check axillary tail of breast tissue, level III, and tissue posterior axilla
** Haemostasis and ray-tec, leave wound open for closing later

== Difficulties: ==

* No nodes found
** Inject 10mL saline peri-areolar and further massage
** Next step would be level 1 dissection/sampling - consider whether this is justified based on patient factors and disease factors - if younger, more likely to do it
* >3 nodes found
** Controversial whether to take them all or leave them
** Easiest thing to do is leave them after 3 convincing nodes are found

[[Category:Breast]]