Arteriogenesis mechanism of choke vessel remodelling in multiterritory perforator flap in rats

The remodelling of choke vessels within the multiterritory perforator flap (MPF) is intricately associated with the blood supply of the flap. The objective of this study was to elucidate the revascularization mechanism underlying the remodelling of these choke vessels.

Integument radiography and hematoxylin-eosin (HE) staining were utilised to qualitatively and quantitatively evaluate the microvascular morphology within the choke zones. The Evans blue dye was employed to quantify blood flow velocities in the choke arteries within choke zone I, while a laser Doppler blood flow imager was utilised to assess blood perfusion. Immunohistochemistry was also conducted to evaluate the expression of proteins associated with arteriogenesis mechanisms.

In choke zone I, several true anastomotic arteries were observed in the 3d postoperation (PO) group. There was no significant increase in arteriolar density; however, the maximum calibre of arterioles in the 3 d, 5 d, and 7 d PO groups exceeded that of the control group (P<0.05). HE staining showed a decrease in microvessel density and dilation of the microvasculature. The arterial blood flow velocity began to significantly increase at 6 h PO (P<0.05) and reached its peak at 1 d PO. Blood perfusion was higher at 1 d PO than at 6 h PO (P<0.05). The expression of the TRPV4, Ephrin B2, CD11b, MMP-9 and eNOS increased significantly (P<0.05).

Arteriogenesis is likely the key revascularization mechanism involved in choke artery remodelling in choke zone I. Arteriogenesis and angiogenesis play similar roles in choke artery remodelling in choke zone II.