| Background The conception of perforator flaps came of the later period of 1980s. The pioneer were Kojima,Kroll,Wei,Kimura,Blondeel, et al. The clinical applications of perforator flaps have been widespread increasingly after they were used by Gu YD in 1985 in china. But the distal end of the flap were necrotized frequently casued by disturbance of blood circulaton. The wound was repaired by the distal end of the pedicled perforator flap. The proximal end of the pedicled perforator flap is void for the wound repair. It is abortive when the distal end of the flap were necrotized after the operation. Nowadays, there is much debate upon the cause of necrosis of prdicled perforator flaps. Most scholar concident that it is the disturbance of venous return which cause the necrosis of prdicled perforator flaps. After summarize and analyse large numbers of clinical case,we consider that the reason of the distal end necrosis of prdicled perforator flaps related with the pressure difference between arteryes and veins that provide the flaps. To research ulteriorly the relationship between the pressure difference and the necrosis acreage, we established the animal model of distal end necrosis for prdicled perforator flaps on rat back. According to the difference of cutaneous branches blood vessel that provide the flaps,we designed ten kinds of operation. The necrosis acreage of flaps distal end were observed ,so as to provide evidence for clinical operation.Objectives (1)To explore the method and effect of lead oxide suspending liquid injection technique. (2)To explore the anatomic character of dorsal vascular in rats so as to provide evidence for preparing the animal model that study the reason of perforator flap distal end necrosis after the operation.(3)To explore the effect of artery and vein on distal end necrosis of pedicled perforator flaps. Methods1. Lead oxide suspending liquid injection technique.We tested the sedimentation rate of lead oxide suspending liquid of different concentration in fluoroscopy. We radiographed and anatomized the arteries after Wistar rats were perfused with the perfusate.2. Anatomic character for animal model.Anatomise twenty anesthetic rats and the specimen that ten rats' artery were perfused with caoutchouc by inserting the tube through ascending aorta, the feature and variation of the cutaneous branches in rat's back were observed, the anatomy data were measured.3. Animal experiment.The model of necrosis of perforator flaps distal end was set up in male Wistar rats. A hundred rats were randomly divided into 10 groups,with 10 in each.The flaps on the bank for the animal model were provided by the unilateral dorsalis branche of subcostal a.&v.(A1 C1), iliolumbar cutaneous a.&v.(A2 C2), inferior gluteal cutaneous a.&v.(A3 C3). According to saving different cutaneous branches blood vessel,they were randomly divided into 10 groups. The first group(A1C1A2C2 A3C3) include all the three cutaneous branches blood vessel. On the second group (A1A2C2A3C3),the dorsalis branche of subcostal v. was ligated and the other three arteryes and two veins were saved. On the third group (A1A2A3C3), the dorsalis branche of subcostal v. and the iliolumbar cutaneous v. were ligated and the other three arteryes and one vein were saved. On the fourth group (C1A2C2A3C3), the dorsalis branche of subcostal a. was ligated and the other two arteryes and three veins were saved. On the fifths group (A2C2A3C3), the dorsalis branche of subcostal a.& v. were ligated and the other two arteryes and two veins were saved. On the sixth group (A2A3C3), the dorsalis branche of subcostal a.& v. and the iliolumbar cutaneous v. were ligated and the other two arteryes and one vein were saved.On the seventh group (C1C2A3C3), the dorsalis branche of subcostal a. and the iliolumbar cutaneous a. were ligated and the other one artery and three veins were saved.On the eighth group (C2A3C3), the dorsalis branche of subcostal a.& v. and the iliolumbar cutaneous a. were ligated and the other one artery and two veins were saved. On the ninth group(A3C3 ),the dorsalis branche of subcostal a.& v. and the iliolumbar cutaneous a.& n. were ligated and the other one artery and one vein were saved. On the tenth group,all the cutaneous branches blood vessel were ligated.The arteries and veins were ligated and the flaps were sutured in normal position.The necrosis acreage of flaps distal end were observed a week later.The arteries outer diameter and blood-supply diameter in the flaps and the normal sides were observed and measured on the radiograph after Wistar rats were perfused with the lead oxide suspending liquid.Results1. Lead oxide suspending liquid injection technique.The perfusate was prepared as follow: 50ml of water was added to 100 grams of red lead oxide. All the arteries were developed clearly under the X-rays, and the figure were plump.2. Anatomic character for animal model.From crista nuchalis to ischium tuberocity, the six pair of cutaneous branches in rats' back locate in the two side of vertebral column symmetrically.They were posterior auricular a. &v., anterior scapular a.&v., dorsalis branche of lateral thoracic cutaneous a.&v., dorsalis branche of subcostal a.&v., iliolumbar cutaneous a.&v., inferior gluteal cutaneous a.&v..Variance existed in the dorsalis branche of lateral thoracic cutaneous a.. 3. Establish animal model.According to the anatomic character of cutaneous branches blood vessel on rats'bank,the inferior gluteal cutaneous a.&v.were selected as the pedicle. The dorsalis branche of subcostal a.&v. and the iliolumbar cutaneous a.&v. were selected as the selective ligated blood vessel.The medial boundary of the flap is dorsalis midline.The front boundary of the flap is the spinous process of the second thoracic vertebra.The posterior boundary of the flap is the spinous process of the second caudal vertebra.The aspect ratio of the flap is 5:1.4. Animal experiment.The percent of necrosis acreage on distal end of the flaps: The first group 14.20±3.53%,the second group 15.66±3.21%,the third group 16.75±2.75%, the fourth group 21.21±3.29%, the fifths group 22.62±0.91%, the sixth group 22.87±2.01%, the seventh group 46.74±2.56%,the eighth group 48.39±7.10%, the ninth group 52.95±8.50%, the tenth group 100±0%ConclusionsWhen the blood circulation is existent and the number of arteries is invariable,the necrosis acreage on distal end of the flaps is not change as the number of veins increase. When the number of veins is invariable,the necrosis acreage on distal end of the flaps reduce obviously as the number of arteries increase.The necrosis acreage of prdicled perforator flaps distal end is negative correlation with the pressure difference between arteryes and veins that provide the flaps.The arteries that provide the flaps are the primary effect on the necrosis acreage of prdicled perforator flaps distal end.We should save as more arteries that provide the flaps as we can when operation. |
