Changes on noncontrast magnetic resonance imaging following lymphatic surgery for upper extremity secondary lymphedema.

[OBJECTIVE] To assess changes in noncontrast magnetic resonance imaging (MRI)-based biomarkers after upper extremity lymphedema surgery.

[METHODS] We retrospectively identified secondary upper extremity lymphedema patients who underwent vascularized lymph node transplant (VLNT), debulking lipectomy, or VLNT with a prior debulking (performed separately). All patients with both preoperative and postoperative MRIs were compared. An MRI-based edema scoring system was used: 0 (no edema), 1 (<50% fluid from myofascial to dermis), and 2 (≥50% fluid from myofascial to dermis). Edema scores and subcutaneous thickness (ST) were obtained along four quadrants across the upper and lower third of the arm and forearm each-for a total of 16 anatomical locations-and compared before and after surgery. Net changes in edema scores and ST were then correlated with Lymphoedema Quality-of-Life Questionnaire scores, L-Dex (bioimpedance), and limb volume difference by perometry.

[RESULTS] Patients who underwent lymphatic surgeries between January 2017 and December 2022 and successfully completed preoperative and postoperative MRI were included, resulting in a total of 33 unilateral secondary upper extremity lymphedema patients m(mean age, 63 ± 14 years; 32 female). The median postoperative follow-up times were 12.5 months (range, 6-19 months) for VLNT, 13.5 months (range, 12-40 months) for debulking, and 12.0 months (range, 12-24 months) for patients who underwent VLNT after debulking surgery. There was a decrease in mean ST in 15 of 16 anatomical segments of the upper extremity after debulking (P < .001), and the edema score increased in 7 of 16 segments (P ≤ .001-.020). Edema stage did not change in patients who underwent VLNT only or VLNT after debulking. ST decreased only along the radial forearm in patients who underwent VLNT after debulking despite an improvement in the Lymphoedema Quality-of-Life Questionnaire score in the former group. There was correlation between a decrease in ST with a decrease in volume within the debulking group (r = 0.79; P < .001). A decrease in ST also correlated with improved lymphedema quality of life questionnaires in the debulking group (r = 0.49; P = .04).

[CONCLUSIONS] A decrease in ST was demonstrated in most anatomical segments after liposuction debulking, whereas edema stage was increased. Fewer changes were seen with VLNT, possibly a reflection of more gradual changes within this short follow-up period, with the radial forearm potentially revealing the earliest response.