Degenerative vascular changes and risk of anastomosis thrombosis in microsurgical breast reconstruction: A clinical and histomorphometric analysis.

BACKGROUND: Free flap breast reconstruction (FBR) is a well-established option for breast reconstruction, with the internal mammary vessels (IMVs) representing the preferred recipient pedicle. Despite its high success rates, anastomotic thrombosis (AT) remains a challenging complication and few studies have investigated the quality of IMVs and risk factors associated with AT. OBJECTIVES: To assess degenerative changes in IMVs and evaluate risk factors following FBR. METHODS: During recipient vessel preparation for free flap breast reconstruction, 2-3 mm segments of the internal mammary artery and vein were harvested from 97 patients and evaluated using histomorphometric analysis. Vessel degeneration, comorbidities, and oncological treatments were analyzed as risk factors for AT. RESULTS: In the sample of 97 patients (age: 50.4±11.4 years, follow-up: 25.2±12.7 months), AT was observed in 15 (15.4%), and intima and media layer fibrosis (arterial/venous) was not found to be related to AT. Adjuvant chemotherapy was associated with a significantly higher rate of AT (p=0.02). Smoking was significantly associated with arterial medial fibrosis (p=0.01), whereas radiotherapy (p=0.03) and hormone therapy (p=0.02) were associated with venous intimal fibrosis. Hypertension (p=0.01) was associated with venous medial fibrosis. CONCLUSIONS: Despite extensive research, previous anatomical/clinical studies have not analyzed the quality of IMVs in terms of degenerative changes and AT. Our findings indicated that adjuvant chemotherapy was associated with a significantly higher rate of AT, whereas smoking, radiation, and hormone therapies were risk factors for arterial and venous layer fibrosis. Recognition of these associations may support individualized surgical planning and careful assessment of recipient vessel quality.