Factors that influence volume and duration of wound drainage after mastectomy and level III axillary node clearance.

Factors influencing drainage after operations for breast cancer remain controversial. The total volume and duration of drainage was prospectively measured in 252 women undergoing mastectomy and level III axillary clearance, and compared to patient, operative and tumour factors, using multivariate analysis. The total drainage and duration, respectively, correlated with the weight of the patient (r=0.39, P<0.01; r=0.29, P<0.01) and breast weight (r=0.37, P<0.01; r=0.29, P<0.01), and was predicted by the volume on the first postoperative day (r=0.58, P<0.01; r=0.50, P<0.01). There was no correlation with age, blood loss, length of operation, tumour size, number of axillary nodes retrieved, or whether nodes were involved by cancer. The volume and duration of drainage appear thus to be simply a function of the area of tissue planes opened.