[Effect of length-width ratio on partial necrosis in distally based sural neurofasciocutaneous flap: 157 cases].

OBJECTIVE

To explore the effect of length-width ratio (LWR)on partial necrosis in distally based sural neurofasciocutaneous flap.

METHODS

Clinical data and operative pictures of 157 distally based sural neurofasciocutaneous flaps were reviewed and analysed. LWR of the flaps ranged from 2.83:1 to 7.14:1. Based on the LWR of the flaps, the flaps were divided into 5 groups: Group A(LWR≤3:1), Group B(3:1<LWR<4:1), Group C(4:1≤LWR<5:1), Group D(5:1≤LWR<6:1) and Group E (LWR≥6:1). The flaps were harvested by antegrade-retrograde combined method.

RESULTS

Of the 157 flaps, 125 survived uneventfully, 8 had distal epidermical necrosis, wound dehiscence occurred in 6 flaps, 18 flaps(11.5%) had distal partial necrosis. Partial necrosis occurred in none of the 6 flaps in Group A(0%), 4 of 26 flaps in Group B(12.5%), 2 of 56 flaps in Group C (3.6%), 8 of 50 flaps in Group D (16.0%), and 4 of 19 flaps in Group E(21.5%). There were no statistical differences in partial necrosis ratio between Group A and B, Group B and C, Group D and E(P>0.05). Partial necrosis ratio was higher in Group D than that in Group C(P<0.05). It was lower in the LWR<5:1 group (Group A+Group B+Group C) (6.8%, 6/88) than that in the LWR≥5:1 group (Group D+Group E) (17.4%, 12/69) (P<0.05).

CONCLUSION

When LWR of the flap is less than 5:1, probability of partial necrosis occurring in distally based sural neurofasciocutaneous flaps is low, and the flap can survive more reliably. The maximum LWR of the surrival flaps can reach 6-7:1.