Low incidence of milk fistula with continued breastfeeding following radiologic and surgical interventions on the lactating breast

Abstract

Milk fistula is a potential complication of radiologic and surgical procedures on the lactating breast, though its incidence is unknown. Some postulate that larger defects and/or closer proximity to the nipple increase the risk of fistula. This study aimed to estimate the incidence of milk fistula and characterize risk factors in patients who continued breastfeeding after surgical or radiological procedures. A retrospective cohort analysis of pregnant or lactating women treated at a multidisciplinary breast clinic from July 2016 through August 2019 was performed. Demographic and clinical variables were analyzed using ANOVA and Pearson's Chi-square. Two pregnant and 43 lactating patients underwent 71 interventions. The incidence of milk fistula within one week of intervention was 1.4%. One fistula was diagnosed six days after retroareolar abscess drainage. The fistula closed successfully with continued breastfeeding. When categorized by the caliber of the most invasive intervention (large-caliber: mass excision, n =7; medium-caliber: percutaneous drain insertion, n =18; small-caliber: stab incision, aspiration, core needle biopsy, n =20), patients were similar in age, race/ethnicity, weeks postpartum, and frequency of central versus peripheral interventions. The low incidence of fistula prevented quantitative evaluation of potential risk factors. Milk fistula is a rare occurrence following radiologic or surgical breast interventions performed during pregnancy or lactation. Indicated procedures should not be deferred, but periareolar approaches should be avoided when possible. Cessation of lactation is not mandatory for fistula closure, and continued breastfeeding should be recommended.