Mastectomy, axillary lymph node dissection, and irradiation for breast cancer commonly result in perivascular and axillary scarring. This scarring is thought to cause functional venous stenosis that leads to downstream venous hypertension in the affected extremity. Standard surgical practice is to decompress perivascular scarring at the time of physiologic lymphedema surgery in patients with breast cancer-related lymphedema (BCRL). However, it is unknown whether this scar release influences surgical outcomes. The purpose of this study was to evaluate the prevalence of functional venous stenosis in patients with BCRL and determine whether scar decompression is a necessary step in physiologic lymphedema surgery. The authors conducted a retrospective review of 64 patients with unilateral BCRL that presented to our lymphedema center between January 2020 and October 2022. Radiologist reports of venous duplex ultrasound for the bilateral upper extremities identified any disturbances in venous flow or indications of venous stenosis. Of the 64 patients with BCRL, 78% (n = 50) had prior axillary lymph node dissection. Forty-seven (73%) patients completed ultrasound imaging, of which, one patient (2%) had venous stenosis in the affected lymphedematous extremity identified on duplex ultrasound that may have suggested functional scarring. Vascularized lymph node transfer (VLNT) without scar decompression was performed in six patients (9%). Average preoperative Lymphedema Life Impact Scale and Lymphedema Index scores were 35 and 19 units, with a mean decrease of 23 (67%) and 6 (30%) units postoperatively. Most patients with BCRL did not have identifiable functional venous stenosis on duplex ultrasound, apart from one patient with suspected postthrombotic changes. All six patients that received VLNT without scar decompression had a successful outcome with decreased measures of lymphedema postoperatively. Scar decompression may therefore be unnecessary in physiologic lymphedema surgery, reducing operative times and avoiding risk of injury to neurovascular structures of the axilla.