Endoscopic mastectomy

Pre-operative marking and positioning

Pre-operative marking was done with the patient in standing and supine position. After induction of general anaesthesia, the patient was then placed in supine position and ipsilateral arm abducted to 90 degrees to avoid affecting the operative procedure. Endoscopic video monitors (Olympus Optical Co., Tokyo, Japan) were set up on both sides of the patient's head to allow both the surgeon and assistant to view the monitor. An oblique-ended rigid endoscope measuring 5 mm in diameter with a viewing angle of 30 degrees was used in all procedures.

Axillary staging procedure

In patients for whom sentinel lymph node biopsy (SLNB) is indicated, a small amount (2–3 mCi) of radioisotope Tc99m was injected intradermally at the site of the tumour before operation (either on the day or 1 day prior).

After induction of general anaesthesia, 3 mL of 1% methylene blue (Merck, Darmstadt, Germany) was injected into the breast parenchyma in equally divided aliquots at five positions surrounding the hemisphere of the tumour facing the ipsilateral axilla. The breast tissue from the tumour to the axilla was then gently massaged for 5–10 minutes. Within 20–30 minutes after injection of the blue dye, a handheld gamma probe (Navigator; USSC, Norwalk, CT) was used to identify the hot spots, and the location of the hottest nodes was then marked. An approximately 3-cm oblique axillary incision was then made close to the hottest nodes, and SLNB was then performed. Fresh frozen section was performed as indicated. If SLN was positive for metastases, a complete axillary lymph node dissection up to level II was performed.

Dissection of breast parenchyma off pectoralis major fascia

The margin between pectoralis muscle and breast parenchyma was clearly identified. An endoscopic Ultra Retractor (Johnson & Johnson KK or Karl Storz) vein harvester was used for the dissection of pectoral muscle fascia off posterior portion of breast parenchyma. The penetrating vessels were coagulated and cut with bipolar scissors (PowerStar, Johnson & Johnson KK) or a harmonic scalpel to ensure adequate haemostasis and therefore better visual clarity. Counter traction was applied by retracting surrounding tissue with the Ultra Retractor under endoscopic guidance to create a sufficient working space, and a suction tube can be used to evacuate mist and smoke.

Placement of single port, tunnelling, and development of skin flap (in cases of endoscopic mastectomy with insufflation technique)

To create a working space for placement of the single port (Glove Port; Nelis Corporation, Gyeonggi-do, Korea), a 3–4 cm subcutaneous flap was dissected with electrocautery under direct vision. Once adequate dissection was achieved, the single port was then inserted through the axilla incision and carbon dioxide (CO ₂ ) insufflation with air pressure kept at 8 mmHg was used to create space for mastectomy. Dissection was then continued from the superficial skin flaps by dissecting the septa between the skin flap and parenchyma created by the tunnelling technique with monopolar scissors. A sub-areolar biopsy and fresh frozen section analysis can be performed in a nipple-sparing mastectomy. If cancer cell invasion was found in the sub-areolar area, the entire nipple-areolar complex (NAC) was removed and conversion to a skin-sparing mastectomy was then performed. After completion of the superficial skin flap dissection, dissection of the peripheral portion of the breast parenchyma was carried out subsequently. After completion of dissection, the entire breast specimen was removed through the axillary wound.

Tunnelling and development of skin flap (in cases of endoscopic mastectomy with retraction technique)

After completion of the axillary staging procedure, a semi-circular peri-areolar skin incision or a single axillary incision was made (depending on surgeon's preference) as previously described. A physiological saline solution containing lidocaine 0.05% and epinephrine 1:1,000,000 was injected subcutaneously into the whole breast to minimize bleeding. An approximately 3–5-mm-thick skin flap was created via tunnelling method using an optical bladeless trocar Xcel (Johnson & Johnson, Tokyo, Japan) under endoscopic guidance. Subsequently, the septa between the skin flap and parenchyma was dissected and taken off under endoscopic guidance using endoscissors, bipolar scissors, or a harmonic scalpel.