Biomedical subjects

Daping Yang

Publications and source records attributed to Daping Yang.

10 recordsLinked to original sources

PubMed2006

A modified longitudinally split segmental rectus femoris muscle flap transfer for facial reanimation: anatomic basis and clinical applications.

The present study was conducted to investigate the intra-muscular neurovascular anatomy and the intra-muscular tendon distribution of the rectus femoris muscle to reassess the reliability of technique of harvesting a longitudinally split segmental muscle flap, and to present our clinical experience on usefulness of the longitudinally split segmental rectus femoris muscle flap as a method for reconstruction of the paralysed face in a series of 25 patients. Twenty fresh cadavers were systemically injected with lead oxide, gelatin and water. Based on the anatomy of intra-muscular neurovascular structure in the rectus femoris muscle, 25 consecutive patients with established facial paralysis were treated by using a two-stage method combining neurovascular free-muscle transfer with cross-face nerve grafting. Follow-ups were 15-24 months. All of the 25 patients showed significantly improvement in the appearance of the oral commissure and oral competence. Satisfactory results of facial reanimation were obtained in 23 patients. Among these cases, near-natural facial expression was achieved. Recovery continued up to 2 years postoperatively. There were two cases having poor movement of transferred muscle 2 years postoperatively. No complications occurred in the donor site. In conclusion, the present study has demonstrated the suitability for subdivision of the segment muscle flap of the rectus femoris into two functional units with a common neurovascular pedicle. This series has further demonstrated the safety and reliability of using the rectus femoris muscle flap for facial reanimation.

Adolescent↗

PubMed2005

Tissue-engineered vessel strengthens quickly under physiological deformation: application of a new perfusion bioreactor with machine vision.

In order to develop a patent tissue-engineered blood vessel that grossly resembles native tissue, required culture times in most studies exceed 8 weeks. For the sake of shortening the maturation period of the constructs, we have used deformation as the basic index for mechanical environment control. A new bioreactor with a machine vision identifier was developed to accurately control the deformation of the construct during the perfusion process. Two groups of seeded constructs (n = 4 per group) were investigated in this study, with one group stimulated by a cyclic deformation of 10% and the other by a pulsatile pressure that gradually increased to 120 mm Hg (the control group). After 21 days of culture, the mechanical properties of the constructs were examined. The average burst strength and suture retention strength in the two groups were significantly different (t test, p < 0.05). For the experimental group, the average burst strength and suture retention strength were higher than those of the control group, by 31.6 and 23.4%, respectively. Specifically, the average burst strength of the constructs reached 1,402 mm Hg (close to that of the native vessel, i.e. 1,680 mm Hg) within a relatively short period of 21 days. In conclusion, deformation is an observable, controllable and very valuable index for mechanical environment control in vascular tissue engineering. It makes the control of mechanical stimuli more essential and experiments more comparable.

Animals↗

PubMed2005

Applying informatics in tissue engineering.

OBJECTIVE: To facilitate tissue engineering strategies determination with informatics tools. METHODS: Firstly, tissue engineering experimental data were standardized and integrated into a centralized database; secondly, we used data mining tools (e.g. artificial neural networks and decision trees) to predict the outcomes of tissue engineering strategies; thirdly, a strategy design algorithm was developed, and its efficacy was validated with animal experiments; lastly, we constructed an online database and a decision support system for tissue engineering. RESULTS: The artificial neural networks and the decision trees respectively predicted the outcomes of tissue engineering strategies with the predictive accuracy of 95.14% and 85.26%. Following the strategies generated by computer, we cured 18 of the 20 experimental animals with a significantly lower cost than usual. CONCLUSION: Informatics is beneficial for realizing safe, effective and economical tissue engineering.

Artificial Intelligence↗

PubMed2003

Reversed forearm island flap supplied by the septocutaneous perforator of the radial artery: anatomical basis and clinical applications.

The cutaneous perforators of the radial artery adjacent to the superficial branch of the radial nerve and the lateral antebrachial cutaneous nerve were investigated, and the vascular anatomical features of the reversed forearm island flap supplied by those accompanying perforators were documented. Ten fresh cadavers were systemically injected with lead oxide, gelatin, and water. Twenty forearms were then dissected, and an overall map of the cutaneous vasculature and source vessels was constructed. The accompanying arteries were observed to lie along the lateral antebrachial cutaneous nerve and the superficial branch of the radial nerve and to nourish the skin through cutaneous branches. Vascular communication among these cutaneous vessels was evaluated, to determine the cutaneous vascular territory of the radial forearm flap. This anatomical information facilitates flap design in the forearm region. Clinical experience regarding the usefulness of the reversed forearm island flap for hand reconstruction for a series of five patients is presented.

Adult↗

PubMed2003

Neurovascular territories of the external and internal oblique muscles.

The purpose of this study was to document the extent of the arteries supplying the external and internal oblique muscles and the connections among the vascular territories. Ten adult human cadavers underwent whole-body arterial perfusion (200 ml/kg) with a mixture of lead oxide, gelatin, and water, through the carotid artery. The external and internal oblique muscles were dissected and subjected to radiography. The vasculature of each muscle was analyzed by using the paper template technique. The areas of the vascular territories of the individual intercostal arteries within the external oblique muscle varied from 9 to 22 percent. The area of the vascular territory of the muscular branch of the deep circumflex iliac artery was 5 to 18 percent. The ascending branch of the deep circumflex iliac artery supplied a mean of 35.7 percent of the vascular territory of the internal oblique muscle. The lower six posterior intercostal arteries supplied a mean of 48.5 percent. The lateral branches of the deep inferior epigastric artery supplied a mean of 15.8 percent. This information provides the basis for the design of external and internal oblique muscle flaps for functional muscle transfer.

Abdominal Muscles↗

PubMed2003

Cutaneous vasculature of the forearm.

Five fresh human cadavers were injected with lead oxide, gelatin, and water. Nine forearms were dissected and an overall map of the cutaneous vasculature by source vessel was constructed. The average number of arterial perforators per source vessel was calculated. The forearm was then divided into three regions, and the density of perforators per region was calculated and compared. The overall number of arterial perforators decreases from proximal to distal in the forearm, but the overall density of perforators 0.5 mm or larger remains uniform. It was observed that the distal third of the forearm has a rich supply of smaller caliber arterial perforators compared with the proximal two-thirds of the forearm. The angiographic studies demonstrate a series of arterial perforators arising from the radial and ulnar arteries. The perforators in turn are linked longitudinally with other perforators from the same source vessel and transversely with the other major vessel. An understanding of this pattern of arterial supply of the forearm integument is helpful for the design of pedicled skin flaps and perforator flaps in the forearm.

Forearm↗

PubMed2003

Variability in the vascularity of the pectoralis major muscle.

OBJECTIVE: Although the pectoralis major muscle has been the subject of numerous anatomic studies over the past 20 years, there remains a high complication rate for pedicled pectoralis musculocutaneous flaps. In this report, angiograms of 43 pectoralis major muscles were studied to assess the vascular territories of its three arterial supplies: lateral thoracic artery, the pectoral branch of the thoracoacromial artery, and the anterior intercostal perforators of the internal mammary artery. METHODS: Twenty-two adult human cadavers underwent whole-body arterial perfusion (200 mL/kg) with a mixture of lead oxide, gelatin, and water through the carotid artery. All pectoralis major muscles were dissected and radiographed. Radiographs were photographically printed as contact prints. The vasculature of each muscle was analyzed using the paper template technique. RESULTS: The pectoral branch of the thoracoacromial artery supplied 50.7% of the vascular territory of the pectoralis major. The lateral thoracic artery was present in 37 of 43 angiograms and supplied a mean territory of 6.6%. The anterior intercostal perforating branches of the internal mammary artery supplied 43% of muscle parenchyma. There was considerable variability in the extent of various vascular territories from muscle specimen to specimen. CONCLUSION: Despite excellent surgical technique, certain pedicled musculocutaneous pectoralis major flaps may suffer partial distal necrosis simply owing to the relatively small vascular territory of the pectoral branch of the thoracoacromial artery.

Adult↗

PubMed2002

Reversed sural island flap supplied by the lower septocutaneous perforator of the peroneal artery.

The current study was conducted to document the vascular anatomy of the distally based superficial sural artery flap and to study the vascular anastomoses between the superficial sural artery and the septocutaneous perforator of the peroneal artery. Five fresh human cadavers were injected with lead oxide, gelatin, and water. Ten legs were then dissected and an overall map of the cutaneous vasculature by source vessel was constructed. Vascular communication between the superficial sural artery and the lowest septocutaneous perforator of the peroneal artery was evaluated to determine the cutaneous vascular territory of the superficial sural flap. This anatomic information enhances our understanding of flap design. The authors' clinical experience with the usefulness of the distally based island flap as a method of reconstruction in the lower leg and foot in a series of 26 patients is presented.

Adult↗

PubMed2002

[Effect of triton X-100 on preparing porcine thoracic aortas acellular matrix].

OBJECTIVES: To investigate the method of preparing porcine thoracic aortas acellular tissue matrix (ACTM) by trypsin, EDTA and Triton X-100 and to find the best concentration of X-100. METHODS: A total of 56 roots of fresh thoracic aortas (without adventitial tissue) from 80 kg-100 kg tame pigs were divided randomly into > groups, each containing 8 roots. Every vessel was put into a 50 ml centrifugal tube with a solution of 0.1% trypsin + 0.02EDTA in PBS for 24 h. After that, each group was separately immerged into a solution of 0.1%, 0.2%, 0.5%, 1.0%, 2.0%, 5.0%, 10.0% Triton X-100 for 144 h-240 h. Specimens were taken every 6 h. Specimens were stained with haematoxylin-eosin and observed grossly under the light and transmission electron microscopy. RESULTS: Light and transmission electron microscopy revealed that ACTM was composed of insoluble collagen, elastin, and some insoluble metamorphic organelles. The best concentration of Triton X-100 was 1% at the time of 176.25 h +/- 5.5 h. CONCLUSIONS: Porcine thoracic aortas ACTM can be obtained successfully through this procedure. Triton X-100 is a good reagent for preparing vessel ACTM.

Animals↗

PubMed2002

[Effects and mechanism of ischemic preconditioning on the survival of axial flaps in rats].

OBJECTIVE: This study was to develop a new method that can improve flap survival. METHODS: A long skin flap spanning the full length of the rat dorsum was used to make a bilateral skin tube, which was based on the lateral thoracic artery proximally, and the deep circumflex iliac artery distally. The animals were randomly divided into 3 groups of 8 rats in each group: the control and two experimental groups with elevation of the tube (the proximal pedicle divided) immediately or 24 hours following ischemic preconditioning. All tube flaps were observed for 3 days postoperatively and the surviving flap area was measured as a percentage of the whole flap using the paper template technique. Heat shock protein 70 in the three groups was examined by means of immunohistochemistry. RESULTS: There was an overall statistical significance in comparison of flap survival of the preconditioned flaps with that of the controls. There was no statistical significance between the two preconditioned groups. Heat shock protein 70 (HSP70) was demonstrated immunohistochemically in the preconditioned skin flap but not in the control skin flap. CONCLUSION: Ischemic preconditioning can improve skin flap survival and the contents of HSP70. It is suggest that the mechanism be related to the function of HSP70.

Animals↗