Skin as marker for collagen type I/III ratio in abdominal wall fascia

An altered collagen metabolism could play an important role in hernia development. This study compared collagen type I/III ratio and organisation between hernia and control patients, and analysed the correlation in collagen type I/III ratio between skin and abdominal wall fascia.

Collagen organisation was analysed in Haematoxylin-Eosin sections of anterior rectus sheath fascia, and collagen type I/III ratio, by crosspolarisation microscopy, in Sirius-Red sections of skin and anterior rectus sheath fascia, of 19 control, 10 primary inguinal, 10 recurrent inguinal, 13 primary incisional and 8 recurrent incisional hernia patients.

Compared to control patients [7.2 (IQR = 6.8-7.7) and 7.2 (IQR = 5.8-7.9)], collagen type I/III ratio was significantly lower in skin and anterior rectus sheath fascia of primary inguinal [5.2 (IQR = 3.8-6.3) and 4.2 (IQR = 3.8-4.7)], recurrent inguinal [3.2 (IQR = 3.1-3.6) and 3.3 (IQR = 3-3.7)], primary incisional [3.5 (IQR = 3-3.9) and 3.4 (IQR = 3.3-3.6)] and recurrent incisional hernia [3.2 (IQR = 3.1-3.9) and 3.2 (IQR = 2.9-3.2)] patients; also incisional and recurrent inguinal hernia had lower ratio than primary inguinal hernia patients. Furthermore, collagen type I/III ratio was significantly correlated (r = 0.81; P < 0.001) between skin and anterior rectus sheath fascia. Finally, collagen organisation was comparable between hernia and control patients.

Furthermore, in both skin and abdominal wall fascia of hernia patients, collagen type I/III ratio was lower compared to control patients, with more pronounced abnormalities in incisional and recurrent inguinal hernia patients. Importantly, collagen type I/III ratio in skin was representative for that in abdominal wall fascia.