Abstract
"Surgical delay" is aimed at increasing blood flow to adjacent angiosomes by opening choke vessels, to obtain larger and more reliable flaps. We hypothesized that staged elevation (delay) from distal to proximal, in addition to preservation perforator artery near the base will improve survival. Thirty-two Sprague-Dawley rats were divided into 4 groups and 3x8cm caudal McFarlane flaps were elevated. In "delay" groups the 3 × 4 cm distal part was elevated and sutured back, with complete elevation (3 × 8 cm) after 4 days. The deep circumflex iliac artery (DCIA) at the base was either preserved or transected. The groups were: group A (Delay/DCIA preserved), group B (Delay/DCIA transected), group C (No Delay/DCIA preserved), group D (No Delay/DCIA transected). The percentage of surviving flap area was measured after 7 days with digital planimetrics. Statistics were done with ANOVA and unpaired T-test. The survivals were: 98.44 ± 3.13 %(group A), 69.33 ± 5.51 %(group B), 76.50 ± 8.91 %(group C) and 52.89 ± 3.15 %(group D). Delay lead to a greater degree of survival whether the arteries were preserved (p = 0.002) or transected (p = 0.01). In groups where the DCIA was preserved, the delay lead to a greater area of survival (p = 0.002). Inclusion of arteries lead to a greater degree of survival whether delay was performed (p = 0.003) or not (p = 0.005). Necropsy showed that the DCIAs were dilated bilaterally when preserved with vascular arcades reaching all viable areas. When the DCIA was transected, the gluteal perforators were dilated bilaterally with the vascular arcades reaching all viable areas. Staged elevation is an effective method of delay in both random and rando-axial flaps. When this is combined with preserving the perforator artery, survival rates are further enhanced.