Skin/Soft tissue

Question 1

Melanoma Excision

Answer 1

Radical Wide Excision

Minimum margins are measured from biopsy site/residual tumor and an elliptical skin incision created
Dissection carried down to deep fascia
Wound closed in layers

Sentinel Lymph Node Biopsy

Patient reports to nuclear medicine for intradermal injection of 99-technetium sulfur colloid to biopsy/tumor site-Lymphoscintigraphy defines drainage pattern (can use SpectCT for better visual of nodal basin around neck)
In the OR, the gamma probe used to confirm location of sentinel node(s)
Isosulfan blue dye is injected around the biopsy/tumor site (1cc of 1%)
Targeted dissection using the gamma probe and visualization of blue dye
Nodal excision is complete once only background signal detected by probe without any residual visible blue or suspicious nodes
Sentinel nodes sent for permanent (frozen no good)

Potential Pitfalls

Failure to anticipate need for skin graft or complex closure
Neurovascular injury during dissection
Failure to orient sentinel node biopsy incision to facilitate future completion node dissection
Intraoperative frozen section should generally not be performed

Question 2

LN Inguinal dissection

Answer 2

The patient is positioned supine with the leg flexed and externally rotated in the frog-leg position.
An oblique, slightly S-shaped incision is created starting medial to the anterior superior iliac spine and coursing to a point 1–2 cm below the apex of the femoral triangle. An ellipse of skin over the palpable mass is included in the resection.
Progressively thicker flaps are raised laterally to the sartorius muscle, medially to the adductor longus and superiorly to a line from the pubic tubercle to the anterior superior iliac spine.
The lymph node–bearing tissue is then excised from over the femoral nerve, artery, and vein and off of the external oblique aponeurosis.
A deep dissection can be performed by creating a separate incision in the external oblique aponeurosis or by dividing the inguinal ligament.
The peritoneum and ureter are retracted medially to expose the iliac fossa. The iliac nodes are dissected off the common and external iliac vessels. The obturator nodes are dissected off the posterior surface of the external iliac vein.
After closure over a deep drain, the sartorius is mobilized and transposed to sit over the exposed femoral vessels.
A superficial drain is placed and the incision is closed.

Potential Pitfalls
Injury to the spermatic cord structures or the contents of an unexpected hernia.
Injury to the femoral or iliac neurovascular structures.
Injury to the ureter.
Bleeding from the obturator and iliac veins.

Question 3

Sarcoma Ex

Answer 3

Preoperative MRI assesses tumor size and proximity to surrounding structures, and core needle biopsy determines histologic subtype and pathologic grade. Review case in multidisciplinary tumor board (or refer to sarcoma center) to determine optimal multimodality therapy.
Surgical incision is oriented along the longitudinal axis of the extremity, unless this compromises options for complex soft tissue reconstruction.
STS is completely removed en bloc with a margin of uninvolved soft tissue (1cm) and adjacent fascial layers.
Nerves and vessels critical to limb function are preserved. Segment of a vessel encased by tumor, however, can be removed when vascular reconstruction is feasible.
Orient the pathologic specimen and assess the margin of resection. Consider delayed reconstruction if margin status is uncertain.
Place metallic clips within the surgical site as markers for adjuvant radiation.
Close the skin and subcutaneous tissues over surgical drains, when needed. Consider physical and/or occupational therapy evaluation following surgery.

Potential Pitfalls
Circumferential scar from surgical biopsy or prior resection requires more radical soft tissue resection.
Intraoperative assessment of the tumor margins is challenging.
Need for complex reconstruction to close the surgical site.