Patients
Procedures were performed on breast cancer patients (N = 60) between March 2019 and May 2020 at the Beijing Friendship Hospital. Patients with early invasive breast cancer (stage I and II) as confirmed by core needle biopsy and with clinically negative axilla were enrolled in the present study. Patients with tumors > 5 cm, clinically or radiologically suspicious lymph nodes, inflammatory breast cancer, distant metastatic tumor, previous axillary surgery, or hypersensitivity to iodine or ICG were excluded from the study.
After recruitment, patients were divided into three groups. Twenty patients who underwent SPE-SLNB combined with ICG and CNs were placed in group A. Another 20 patients who underwent SPE-SLNB using CNs only were placed in group B. The remaining 20 patients who underwent C-SLNB using ICG and CNs were placed in group C.
Surgical technique
Group A (SPE-SLNB combined with ICG and CNs)
The patient was in a supine position with a high shoulder cushion on the affected side. The upper limb was wrapped in a sterile towel and placed at a 90° abduction. ICG (25 mg, Yichuang Pharmaceutical LLC, Dandong, China) was dissolved in 10 mL sterilized distilled water before use, and the mass concentration was 2.5 mg/mL after dissolving. Then the ICG was further diluted to 0.5 mg/mL in 1 mL of sterilized distilled water for use. Intradermal injection of 0.3 mg/mL of ICG and 0.2 mL of CNs (Chongqing LUMMY Pharmaceutical, Chongqing, China) were injected at the outer and lower margins of the areola. Tumescent solution was injected into the axilla to facilitate liposuction. The formula of the tumescent solution was 1 mg adrenaline and 20 mL of 2% lidocaine mixed with 250 mL of 0.9% sodium chloride and 250 mL of sterilized distilled water. A total of 100 mL of tumescent solution was injected into the SLN region with a blunt lipolysis needle at the top. After 15 minutes, we performed liposuction in this area.
A small single-port incision about 2.5 cm in length was created with the single-port insufflation kit (HTKD-Hang T Port, China) (Fig. 1) at the axillary midline flush with the nipple and filled with CO2 gas. The pressure was maintained at 8 mmHg (1 mmHg = 0. 133 kPa), and the gas flow rate was kept at 8 L/min. This established adequate working space for the operation. Then, endoscopic surgical instruments and the near-infrared fluorescence endoscopy of FloNavi™ Endoscopic Fluorescence Imaging System (Optomedic Technique Inc., Guangdong, China) (Fig. 2) were implanted through the single-port insufflation kit. The endoscopic fluorescence imaging system emits an excitation light at 760 nm, which produces the fluorescence of ICG that is displayed by computer processing. The near-infrared fluorescence endoscopy also magnifies the area to easily detect the fluorescence of the ICG in the SLNs and the lymphatic vessels connected to it (Fig. 3). The lymphatic vessels surrounding the SLNs were clipped, and the SLNs visible with fluorescent lymph nodes (ICG +) and/or black-stained lymph nodes (CN +) were removed (Fig. 4). The SLN specimens were removed through the single-port insufflation kit and sent for intraoperative frozen pathology. Patients who did not conform to the Z0011 criteria continued to receive endoscopic axillary lymph node dissection through the single-port incision. On the contrary, if a patient met the Z0011 criteria, then the surgical field was washed with physiological saline, and a silicone drainage tube was placed to connect the negative pressure suction. The drainage tube was removed three days after operation. Patients receiving single-port endoscopic subcutaneous mastectomy, breast-conserving surgery, or implanted breast reconstruction were performed through the same single-port incision to complete the follow-up single-port endoscopic surgery. Specific procedures and techniques of single-port endoscopic breast surgery was described previously [6].
Group B (SPE-SLNB with CNs only)
CNs (0.5 mL) were injected into the outer and lower edge of the areola. The placement of the patient’s posture, liposuction, and the establishment of surgical space were the same as in group A. The endoscopic instruments and laparoscope were implanted through the single-port insufflation kit. Then, we separated the fibrous connective tissue in front of the lens, identified the black-stained SLN and its connected lymphatic vessels, clipped the lymphatic vessels around the SLN, and removed all lymph nodes stained with CNs. The extraction, treatment, and other surgical procedures of the specimens were the same as in group A.
Group C (C-SLNB combined with ICG and CNs)
Intradermal injection of 0.3 mg/mL of ICG and 0.2 mL of CNs were injected at the outer and lower margins of the areola, respectively. Then, ICG fluorescence was excited and detected by an in vitro hand-held fluorescence detector (Optomedic Technique Inc., Guangdong, China), and lymphatic drainage was tracked in real time on the monitor. The incision was made 1 cm away from the disappearance of the fluorescence. The fluorescent lymph nodes (ICG +) and/or black-stained lymph nodes (CN +) were detected under direct vision, and the C-SLNB was completed. Once the SLN specimens were removed, they were sent for intraoperative frozen pathology. The removal of specimens and the treatment of the axilla were the same as group A. Finally, the breast surgery was performed through traditional open surgery.
If the fluorescent lymphography was undetected, then we made a routine incision in the axilla of the patient. When the skin and subdermal fat were incised, the black-stained lymph nodes were resected.
Evaluation of SLNs and arm function
The detection rate of SLNs, mean number of SLNs, and the physical function of the upper limbs were evaluated. In order to evaluate the physical function of the upper limbs, clinicians performed sensory evaluation at one month and six months after surgery. The patients were contacted by telephone for follow-up. The upper arm pain score (PS) was measured by the visual analogue scale. If PS = 0, then it was reported as no pain; if PS = 1–3, then it was reported as mild pain; if PS ≥ 4, then it was reported as moderate to severe pain. The degree of sensory loss at the upper arm was also measured by the visual analogue scale. The scale ranged from 0 (no change in sensation) to 10 (complete loss of sensation).