Study Of The Vascular Structure And Clinical Application Of The Deep Inferior Epigastric Artery Perforator Flap

The deep inferior epigastric artery perforator(DIEAP) flap,updated from rectus abdominis myocutaneous flap,has been widely used in the reconstruction of vulva, upper and lower extremities,head and neck,and especially in the breast reconstruction.The designs of the flap vary,including pedicled island flap for perineal defect,free transplantation for distant area,thinned flap according to the recipient site, paraumbilical perforator flap without deep inferior epigastric vessels,or double-pedicle perforator flap to improve the flap perfusion.However,the DIEAP flap induces much controversy in the perfusion zones,the vascular structure of the perforator,the perfusion mechanism of the blood supply,and the safe level for flap thinning.The literatures related to these problems are rare.This study tries to analyze and solve these disputes according to the findings of anatomic and radiological research.Recently,computed tomography angiography(CTA) has been found valuable in preoperative planning of DIEAP flap because it can provide useful imaging information for abdominal vasculature.The study is also designed to investigate the technical demand for the examination and the steps to analyze the radiological images,which is compared with surgical findings.Objective(1) The study of anatomy,radiology and CTA were made to investigate the deep inferior epigastric vessels,their perforators and the superficial inferior epigastric vein, including the origin,course,bifurcations,distribution,and anatomic relationships of these vessels.(2) Four dimensional CT angiography was used to investigate the vasculature of the DIEAP flap,including the perforator vasculature,the perfusion mechanism of the blood supply,and the safe level for flap thinning.(3) To explore the application of CTA in preoperative planning of DIEAP flap, including radiologic study technique and protocol image analysis(4) To establishes three-dimensional model of the DIEAP flap based on CTA and investigates the procedure of the model in clinical use.(5) To investigates the indications and the forms of the DIEAP flap,tests the former research and evaluates the clinical value of CTA examination.Method(1) Anatomic research was applied to study the abdominal vasculature of the arterial and venous system,with the artery perfused by red latex and the vein by blue latex.(2) Four dimensional CTA was made to investigate the vasculature,course, anastomosis in the midline,perfusion mechanism(3) Preoperative abdominal CTA was made to plan the DIEAP flap according the radiological image,including the origin,course,bifurcations,distribution,and anatomic relationships of the deep inferior epigastric vessels,their perforators and superficial inferior epigastric vein.(4) The three dimensional model of the DIEAP flap was made in the CT workstation and compared with surgical findings.(5) We summarized 16 DIEAP flaps for different indications and in different forms to evaluate the clinical value of the DIEAP flap.Result(1) The deep inferior epigastric artery(DIEA) derived from external iliac artery courses medially and superiorly to the rectus abdominis muscle.The deep inferior epigastric artery gives off rami in the rectus abdominis muscle.The patterns of the DIEA branches include three types:single-branch,double-branch and three-branch. High numbers of perforators are found in the paraumbilical region,especially the large perforators(φ＞lmm).The deep inferior epigastric vein(DIEV) accompanies the DIEA,has direct anastomosis with superior inferior epigastric vein(SIEV).The SIEV is the main vein of the anterior abdominal wall and located superior to Scarpa fascia. (3) The perforators of DIEA give off rami within the superficial adipose layer and the subdermal plexus.The blood supply spreads in two methods,one is the subdermal plexus and the other is former vasculature(fast track).(3) The images obtained from the CTA and three-dimensional model perfectly display the origin,course,bifurcation,and anatomic relationships of the DIEAP flap.(4) The 16 DIEAP flaps were successful,and the preoperative design based on abdominal CTA was well accorded with surgical findings.Conclusions(1) Anatomic study,radiological study and CT angiographic study are ideal methods to study the abdominal vasculature,which compensates with each other.(2) Four dimensional CTA is a useful method to study the vasculature of the DIEAP flap.(3) The CTA can be used as a routine method to investigate the DIEAP flap.(4) The three-dimensional simulation can also be used as a routine method to plan the DIEAP flap.(5) The DIEAP flap is an useful flap with good blood supply,in different forms and for different indications...