Background and Aims: For lactational mastitis developing into a breast abscess, the conventional treatment method is surgical incision and drainage. However, this traditional method has the disadvantages such as surgical invasiveness, severe pain during dressing change, long treatment time and apparent scars after wound healing, and even causes forced termination of lactation in some patients. Therefore, this study was attempt to use a novel minimally invasive endoscopic approach for the treatment of breast abscess during lactation period, and to analyze its efficacy.  
Methods: The patients with lactational breast abscess meeting inclusion criteria admitted from February 2012 to February 2018 were enrolled, and were randomly allotted to two groups to undergo ultrasound-guided abscess puncture with endoscopic exploration and flushing plus catheter drainage (minimally invasive endoscopic group), and conventional open surgery with gauze drainage (conventional group).  The relevant clinical efficacy variables were compared between the two groups of patients.
Results: A total of 97 patients were enrolled with 49 cases in minimally invasive endoscopic group and 48 cases in conventional group, and all patients were female. There were no significant differences in general data before treatment between the two groups of patients (all P>0.05). The frequency of dressing change, time to healing, treatment cost and postoperative cosmetic effect in minimally invasive endoscopic group were significantly superior to those in conventional group (all P<0.05); the surgical trauma and postoperative pain were significantly less, and the incidence rates of mammary duct fistula and milk regurgitation were significantly lower in minimally invasive endoscopic group than those in conventional group (all P<0.05). No recurrence occurred in both groups after treatment.
Conclusion: Minimally invasive endoscopic technique has demonstrable efficacy in the treatment of breast abscess during lactation, which can reduce postoperative pain and the frequency of dressing changes, shorten the treatment time as well as can decrease the treatment cost and the incidence rates of complications, with minimally invasive cosmetic results. So, it is recommended to be widely used in clinical practice.