Influence Of The Length-width Ratio On Partial Necrosis In Distally Based Sural Neurofasciocutaneous Flap: An Analysis Of 179 Flaps

Objective:To explore the influence of the length to width ratio on partial necrosis in distally based sural neurofasciocutaneous flap.Methods:The Clinical data and operative pictures of 179 distally based sural neurofasciocutaneous flap from April 2001 to April 2010 were retrospectively reviewed and analysed.139 cases were male and 40 females, aged 3-78 years, mean 32.4 years old. Trauma caused by a variety of skin and soft tissue defect 159 cases (88.8%). Flap size 5cm×4cm-20cm×15cm.The width of the fascial pedicle 2.5cm 1case,3.0cm 14cases,3.5cm 10cases,4.0cm 119cases,4.5cm 14case,5.0cm 20cases 6.0cm 1ease, among 3.0cm to 5.0cm 177cases(98.8%). Add the long of fascia flap and fascial pedicle from 10.0cm to 30.0cm, mean (19.00±4.16) cm. Flap length to width ratio (2.83-7.14):1, the average (4.72±0.96):1. Flap were divided into 2 groups:survival groups (including the complete survival, shallow necrosis and wound dehiscence), and part of the necrotic tissue groups;under the flap length to width ratio, the flap is divided into A group(aspect ratio<4:1), B group (4:1≤aspect ratio<5:1), C group (5:1≤aspect ratio<6:1) and D group(aspect ratio≥6:1). Flap revealed by first perforating branches of peroneal artery, and then harvesting method combined antegrade and retrograde flap harvesting, use of data for statistical analysis statistical package SPSS 13.0.Results:Of the 179 flaps,141 patients survived totally; shallow necrosis and wound dehiscence distal in 18 cases,dressing in 14 cases,3 cases of secondary suture,1 case of wound healing after skin grafting; flap partial necrosis in 20 cases (11.2%),8 cases of skin graft,32 suture, 3 cases of dressing, three routine flap coverage wound healing, three cases of amputation. A group of 45 cases, partial necrosis in 5 cases (11.1%); B group of 61 cases, partial necrosis in 2 cases (3.3%); C group of 52 cases, partial necrosis in 9 cases (17.3%); D group of 21 cases, partial necrosis,4 (19.0%).The differrences in partial necrsis ratio between group A and group B,group Cand group D,were not statistically different (P>0.05). B, C, D groups flap partial necrosis rates higher and higher. Flap partial necrosis rate of group B lower than C group (P <0.05), flap partial necrosis rates the length to width ratio<5:1 group (6.6%) lower than the length to width ratio≥5:1 group (17.8%) (P<0.05).Conclusions:When the distally based sural neurocutaneous flap aspect ratio≥4:1, the flap partial necrosis rate increases as the length to width ratio of the value of a corresponding increasing trend; the length to width ratio<5:1, the survival more reliable; survival flap length to width ratio up to (6-7):1.