BACKGROUND: Polyvinyl alcohol (PVA) displays limitation to cell adsorbability. Can collagen improve the adsorbability of PVA to cells?OBJECTIVE: To develop a novel type composite of PVA and collagen, and explore the feasibility to serve as soft tissue substitute.DESIGN: Single sample observation.SETTING: Guangzhou Red Cross Hospital, Jinan University Medical College, Guangzhou Institute of Traumatic Surgery.MATERIALS: Fifteen New Zealand rabbits of 2.0-3.0 kg, either male or female, were provided by Medical Experimental Animal Center of Guangdong Province. The experiment was carried out in the Laboratory of Guangzhou Institute of Traumatic Surgery, and the experimental procedure was accorded with the animal ethical standards. Bovine typeI collagen was purchased from Guangzhou Trauer Biotechnology Co., Ltd. and PVA-124 from Guangzhou Chemical Reagent and Instrumentation Co., Ltd.METHODS: The experiment was performed in Guangzhou Red Cross Hospital, Jinan University Medical College between July 2003 and December 2006. ①Preparation of PVA-collagen material: 5 g/L bovine type I collagen was mixed with 5% PVA-124 at a ratio of 1 : 1. The mixture was freeze-dried at vacuum until becoming gelatinous. The internal structure was observed under the use of scanning electron microscope. ②Cytotoxicity test: PVA-collagen composite was cut into pieces of 10 mm×5 mm× 1 mm, put into 48-well culture plate after sterilized by Y ray, cultured with 1×104 3T3 cells in each well. Cell growth was observed under scanning electron microscope and laser scanning confocal microscope. ③Embedding test in vivo: Two longitudinal incisions were cut at the two sides of spine. The subcutaneous tissue was separated bluntly to form subcutaneous lacuna. Four pieces of PVA-collagen material were implanted in the lacuna and fixed. Nine specimens and the surrounding tissues were harvested from three rabbits each at one, four, eight and sixteen weeks postoperatively for pathological observation.MAIN OUTCOME MEASURES: The internal structure of gel film under scanning electron microscope, cytotoxicity test and embedding test in vivo results.RESULTS: ①Internal structure of PVA-collagen material:PVA-collagen material showed white gel shape after freeze-drying at vacuum. Penetrating three-dimensional pores were observed in the surface and inner section under scanning electron microscope. ②Cytotoxicity test results showed that 3T3 cells grew normally on the PVA-collagen material. ? Embedding test in vivo results suggested that one week after PVA-collagen implantation, foreign body reaction occurred, and the interface between material and tissue was clear. Four weeks later, only rare lymphocyte infiltration was observed, and a great amount of fibroblast hyperplasia formed collagen fibrils and false simple cuboidal epithelium coating material. In 8 weeks, no lymphocyte infiltration, neutrophilic granulocyte infiltration or foreign body giant cell were found; dense capsule wall and capsule coating material generated from a great amount of fibroblasts were observed. In 16 weeks, extending collagen fibrils were found arranged regularly with shrank nucleus, showing long ovoid or long fusiform in shape; no new formation small vessels, lymphocyte, neutrophilic granulocyte infiltration or foreign body giant cell infiltration were observed. The capsule wall was stable and thinned. CONCLUSION: PVA-collagen composite has good cell compatibility and tissue compatibility but no toxic or adverse effect. It can serve as in vivo implant.

Objective To investigate the success rate of fluoroscopy-guided subclavian vein catheter implantation (SVCI) in children with hematologic diseases,to improve the visualization of the position of the catheter head,and to reduce the incidence of procedure-related complications.Methods Fluoroscopyguided SVCI was performed in 183 sick children (aged 1-16 years) with confirmed hematologic disease.The success rate of the catheter implantation,the number of needle puncturing,the operation time,the fluoroscopy time and the occurrence of procedure-related complications were recorded.Results Successful fluoroscopy-guided SVCI was accomplished in all 183 sick children,with a success rate being 100％.Successful SVCI was obtained with ＜3 times of puncturing in 151 sick children (82.5％),with 4-6 times of puncturing in 25 sick children,and with 7-10 times of puncturing in 7 sick children.The catheter tip was successfully positioned at the junction of the superior vena cava with the right atrium in all sick children.The operation time ranged from 5 min to 25 min with a mean of (10.38±4.04) min.The fluoroscopy time varied from 16 seconds to 607 seconds with a mean of (65.46±55.86) seconds.During the procedure,artery was wrongly punctured two times in two sick children.The mean follow-up time was 35 days.Cather-related infection occurred in 2 sick children.No local hematoma at puncture point,nor hemopneumothorax or catheter-related thrombosis occurred.Conclusion Fluoroscopy-guided SVCI has high technical success rate in children with hematologic diseases.For a successful procedure of SVCI,less number of needle puncturing is needed by using this technique.The satisfaction rate for the placement of catheter tip is high and the incidence of complications is low.Therefore,fluoroscopy-guided SVCI is a safe and effective method.

OBJECTIVETo evaluate the long-term outcome of the femoral artery following total percutaneous endovascular aortic repair (EVAR) with preclose technique using a vascular closure device (VCD).

METHODSFrom July, 2009 to July, 2012, total percutaneous EVAR was performed in 113 patients (106 males, 7 females; mean age 59.4∓13.5 years) with pre-close technique, including 60 with Stanford type B aortic dissection, 3 with thoracic aortic aneurysm, and 48 with infra-renal abdominal aortic aneurysm, and 2 with thoracic and abdominal aortic aneurysms. The Technical success and complication rates were evaluated, and the outcomes of the femoral artery were followed up with computed tomography or color Doppler ultrasound.

RESULTSThe overall technical success rate was 97.6% (161/165) with conversion to open surgery in 4 cases. The size of the sheaths used were 24Fr (n=37), 22Fr (n=29), 20Fr (n=24), 18Fr (n=25), 16Fr (n=12) and 14 Fr (n=38), and 347 VCDs were used for hemostasis of 165 femoral sites; 147 femoral sites were closed using 2 VCDs. Four access-related adverse events, including femoral arterial-venous fistula, acute femoral thrombosis, bleeding, and lower extremity ischemia, occurred in 4 (2.4%) of the 165 cases. In cases using ≤18Fr sheaths, the success rate of closure using 2 VCDs was 98.7%, as compared to 81.1% in cases using larger (≥20Fr) sheaths (P=0.0003). The success rate of the 82 anterior sites was lower than that of the 82 posterior sites (82.9% vs 95.2%, P=0.013). No lower extremity ischemia was observed, nor was femoral artery stenosis detected during the follow-up for 26∓9 months (12-50 months) in these cases.

CONCLUSIONTotal percutaneous EVAR with preclose technique using VCD provides a safe and effective alternative to open femoral surgery. The sheath size can be a predictor of percutaneous access failure to require conversion to open femoral surgery or using more than 2 devices for suture. Total percutaneous endovascular aortic repair using VCD with preclose technique is safe and effective, which can be adopted as an alternative technique of surgically femoral arterial cut-down operation when the surgeon reduce the learning curve.

Aged ; Aneurysm, Dissecting ; Angiography ; Aortic Aneurysm, Abdominal ; Aortic Aneurysm, Thoracic ; Blood Vessel Prosthesis Implantation ; methods ; Female ; Femoral Artery ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Tomography, X-Ray Computed ; Ultrasonography, Doppler, Color ; Vascular Closure Devices

We have prepared a wound dressing made from chitosan and collagen. Its clinical curative effect was detected. Chitosan solution was put into purified collagen solution. Then, the solution became sponge by means of freeze drying, and it was subjected to a series of toxicology tests, including acute toxicity, stimulation test, allergic and hemolysis tests, as well as the clinical test of openning trauma in orthopedics. All of the results of toxicology tests were negative. The chitosan-collagen sponge could not only accelerate the speed of curing but also restrain the extravasate. Therefore, the chitosan-collagen sponge has good biocompatibility and clinical curative effect. It is a prospective security-biomaterial for medical use.
Biocompatible Materials ; administration & dosage ; Biological Dressings ; Chitin ; analogs & derivatives ; isolation & purification ; therapeutic use ; Chitosan ; Collagen ; isolation & purification ; therapeutic use ; Humans ; Membranes, Artificial ; Wound Healing ; drug effects

This study sought to explore a new compound polyvinyl alcohol-collagen as a wound dressing. To make the polymer, Polyvinyl alcohol (PVA) and collagen type I were put together in the ratio of 3:1, at the same time, polyethlene glycol as porogen was added, and the material was dried by air to be a membrane in shape. Then the ultimate tensile load, the hole diameter, porosity, and water absorption were measured. The cell biocompatibility was tested as well. The results showed the PVA-collagen blend had the average hole 100-150 microm in diameter, and the porosity about 90%. The ultimate tensile load reached 8.10 +/- 0.28 MPa, and water absorption was up to 185.42% +/- 6.93%. 3T3 cells grew well on the PVA-collagen member. Therefore, the PVA-collagen memberane is characterized not only by its ideal biomechanical ability and biocompability, but also by its ideal hole diameter, porosity and water absorption. It may have the potential for use as a wound dressing in vivo.
Biocompatible Materials ; chemical synthesis ; chemistry ; Collagen ; chemistry ; Humans ; Occlusive Dressings ; Polyvinyl Alcohol ; chemistry