Composition of postabdominoplasty seroma

Background:This study aimed to analyze the composition of postabdominoplasty seroma fluid at different intervals, compare it with blood and lymph, and determine whether it meets the criteria for being considered an exudate. Methods: The study enrolled 18 female patients with postabdominoplasty seroma diagnosed by clinical and ultrasound evaluation. All the patients had a Matarasso type 4 anterior abdominal wall deformity. None of the patients were overweight, and none had comorbidities. They all underwent a classical abdominoplasty procedure. Fluid samples were taken from the drains between postoperative days 5 and 7, and from needle aspiration between postoperative days 15 and 20. The fluids were assayed in the clinical laboratory at the University of Chile Clinical Hospital for chemical and cellular composition. Blood, lymph, and seroma values were compared by independent group analysis using a Tukey multiple comparison test with an alpha error of 0.05. Results: The total protein, lactate dehydrogenase (LDH), and cholesterol levels for the early and late seroma fluids were lower than in the blood, but higher than in the lymph. The total protein seroma-to-plasma ratio was approximately 0.5; the LDH seroma-to-plasma ratio was approximately 0.6; and the cholesterol seroma-to-plasma ratio was 0.32. The platelet level was very low in the late seroma fluid, showing no statistical differences with the lymph level. The leukocyte level was low in the seroma fluid, with a higher percentage of neutrophils than found in the blood or the lymph. Conclusions: The serous fluid formed under the flap after an abdominoplasty seems to be an exudate. In the early postoperative period, it is an inflammatory exudate that slowly turns into an exudate with some characteristics similar to those of lymph.