In total, we screened 49 patients and enrolled 47 into the study; we excluded one patient who had undergone other procedures and one who had been treated with an additional dose of dexmedetomidine due to reoperation. The patients' demographic data and dosage information are shown in Table 1. The operating time was 50.1 ± 24.9 minutes, and the anesthetic time was 71.2 ± 28.3 minutes. The mean time from the administration of dexmedetomidine to the start of the procedure was 17.0 ± 5.2 minutes, and the time to recovery after discontinuation of dexmedetomidine was 20.1 ± 10.3 minutes on an average. The dosage information of dexmedetomidine and rescue drug are shown in Table 2. The total dexmedetomidine dose was 101.1 ± 34.1 µg.

In the recovery room, one patient received atropine 0.25 mg due to bradycardia, and one received ramosetron 0.3 mg due to nausea. Systolic and diastolic BP and heart rate were different at the end of procedure compared with the initial BP and heart rate. However, on measuring vital signs, none of the patients had clinically significant hypotension or clinically significant bradycardia (Table 3). No patient needed an advanced airway because of the decreased oxygen saturation during the procedures.

To our knowledge, this is the first report on applying deep sedation in VABB. We believe that applying MAC is effective in patients who are relatively young and in anxious patients and that it increases their satisfaction.

VABB was successfully performed with MAC using dexmedetomidine to sedate patients with no significant complications, and there was no respiratory depression or hemodynamic instability.

Since its introduction in the early 2000s, VABB has revolutionized breast cancer diagnosis and has become a widespread tool and a contributor to therapeutic breast conservation. The most common indication was palpable or nonpalpable American College of Radiology BI-RADS (Breast Imaging Reporting and Database System) lesions in categories 3 and 4.12 Recently, B3 lesion management with VABB (including flat epithelial atypia, papillary lesions, radial scars with atypia, benign phyllodes tumors, and low-grade forms of lobular neoplasia) was recommended instead of surgical excision.13 The paradigm has shifted in favor of VABB as a new minimally invasive excision tool for benign and atypical breast lesions.14

VABB needles have different diameters: 8G, 11G, and 14G. We used the 8G needle, which can collect 250 to 310 mg of tissue (three times more than 11G needles), so that it can resect breast lesions smaller than 3 cm as well as larger ones.12 However, larger needles are associated with procedural pain. Pain is an important adverse outcome of VABB; In addition, Zagouri et al. reported maximum pain VAS scores of more than 6, and patients required second doses of lidocaine.3

Proper sedation as well as local anesthesia are needed to reduce pain and patient stress. With regard to immobility based on needle sharpness or size, deep sedation is more reasonable than light sedation; unexpected movement during VABB is dangerous because the needles are sharp and thick. However, general anesthesia does not take advantage of VABB and increases the cost of medical care; therefore, MAC can be an alternative for deep sedation during VABB instead of local and general anesthesia. In our patients, the BIS scores were low enough to indicate deep sedation.

However, during deep sedation, respiratory depression is always a problem. Therefore, the authors have used dexmedetomidine that is known to have minimal respiratory depressive effects.10 Because dexmedetomidine was used as the main anesthetic in our study, there was no reduction in the respiratory drive that would require advanced airway interventions. Further, it has analgesic and anxiolytic properties and is well tolerated in different age groups across a broad range of surgical and diagnostic procedures. Dexmedetomidine achieves target sedation levels, which is safe and increases patient satisfaction. Patients can be easily awakened just by talking to them, and BIS safely returns to awake levels.9

All procedures were successful, and no patient awoke during surgery. However, an average of 17 ± 5.2 minutes was required until the start of the procedure, and there was an average recovery time of 20.1 ± 10.3 minutes after the operation. The onset time of dexmedetomidine was relatively long compared to the mean operation time (50.1 ± 24.9 minutes), and this was attributable to prolonged dexmedetomidine onset time.11 The mean time from the completion of the dexmedetomidine injection to the time of alertness was 20.1 ± 10.3 minutes due to the slow offset feature of dexmedetomidine. To decrease the procedure time, it is necessary to reduce the onset time or the recovery time which is possible with the administration of additional drugs, such as midazolam or fentanyl, and by reducing the dexmedetomidine dose. In our study, patients who received a high dose of midazolam or fentanyl showed an earlier onset of sedation with a lower dose of dexmedetomidine without any adverse events.

The purpose of this study was to collect and report data on sedating patients with MAC during VABB. However, there were limitations. First, this was a retrospective chart analysis; hence we were not able to compare the satisfaction of VABB patients or practitioners who did not perform MAC. Second, dexmedetomidine does not cause respiratory problems, but it takes longer to sedate. Therefore, further research is needed on how and by how much sedation time can be reduced.

VABB is widely used for its multiple advantages. VABB under dexmedetomidine MAC can reduce the stress and pain of the patient. Although there are disadvantages of increased induction time, appropriate sedation for patient comfort is a more important consideration.