Background: Few concepts are as fundamental to plastic surgery as scarring, yet swelling within a scar and its adjacent tissues is a common observation which is not well understood.

Patients and Methods: Eleven patients with localized swelling in conjunction with linear or curvilinear scars were evaluated, nine with facial scars and two with scars of the chest wall and abdomen. Radiocolloid lymphoscintigraphy was performed on all patients by single or multiple injection technique into the site of the scar corresponding to local edema.

Results: Following injection, rapid egress of radiotracer was visualized along lymphatic pathways posterior to the scar with continuation to locoregional nodes in all patients with “U” shaped “trap-door” scar configuration. However, in nine patients there was no evidence of lymphatic drainage traversing or bridging the scar, consistent with the presence of scar lymphedema.

Conclusions: The findings suggest that undrained lymphatic fluid contributes to the pathogenesis of the raised and swollen tissues seen abutting a “U” shaped scar. Furthermore, as lymphatic pathways are not re-established across scars, Z-plasty revisions may not succeed in patients with clinical “trap-door” scar deformities. Determination of scar lymphedema can assist in the selection of proper management for patients seeking scar revision.