Xiong Qin

Chest wall reconstruction in a canine model using polydioxanone mesh, demineralized bone matrix and bone marrow stromal cells

Extensive chest wall defect reconstruction remains a challenging problem for surgeons. In the past several years, little progress has been made in this area. In this study, a biodegradable polydioxanone (PDO) mesh and demineralized bone matrix (DBM) seeded with osteogenically induced bone marrow stromal cells (BMSCs) were used to reconstruct a 6 cm x 5.5 cm chest wall defect. Four experimental groups were evaluated (n=6 per group): polydioxanone (PDO) mesh/DBMs/BMSCs group, polydioxanone (PDO) mesh/DBMs group, polydioxanone (PDO) mesh group, and a blank group (no materials) in a canine model. All the animals survived except those in the blank group. In all groups receiving biomaterial implants, the polydioxanone (PDO) mesh completely degraded at 24 weeks and was replaced by fibrous tissue with thickness close to that of the normal intercostal tissue (P>0.05). In the polydioxanone (PDO) mesh/DBMs/BMSCs group, new bone formation and bone-union were observed by radiographic and histological examination. More importantly, the reconstructed rib could maintain its original radian and achieve satisfactory biomechanics close to normal ribs in terms of bending stress (P>0.05). However, in the other two groups, fibrous tissue was observed in the defect and junctions, and the reconstructed ribs were easily distorted under an outer force. Based on these results, a surgical approach utilizing biodegradable polydioxanone (PDO) mesh in combination with DBMs and BMSCs could repair the chest wall defect not only in function but also in structure.

Chest wall reconstruction with two types of biodegradable polymer prostheses in dogs

OBJECTIVE Currently, the choice of chest wall prosthesis remains a challenging problem for thoracic and reconstructive surgeons. The purpose of this study is to investigate the feasibility of newly developed biodegradable prostheses. METHODS Two types of chest wall prostheses made from degradable polymer, collagen coated polydioxanone (CCP) mesh and chitin fiber reinforced polycaprolactone (CFRP) strut, were developed and studied. Adult mongrel dogs were subjected to extensive resection and reconstruction of anterior-lateral chest wall, CCP mesh was used in six dogs, the combination of CCP mesh and CFRP strut was used in four dogs, and polypropylene (PP) mesh in two dogs, as contrast. RESULTS With good integration with tissue, CCP meshes maintained strength in the chest wall for more than 8 weeks and were completely resorbed within 24 weeks, and satisfactory short-term and long-term chest wall stabilization was achieved. The combined use of CCP mesh with CFRP strut provided a firmer chest wall in the early postoperative course. A mild wound infection developed in one animal with CCP mesh but resolved without sequelae, and no added complications were observed with the additional use of CFRP strut. CONCLUSIONS Our experimental study shows that the CCP mesh and CFRP prosthesis were favorable for chest wall repair. The advantages of biodegradable copolymer give them promise as an excellent addition to the available reconstructive techniques currently in use.

Video-assisted mediastinoscopic transhiatal esophagectomy combined with laparoscopy for esophageal cancer

BackgroundMinimally invasive transhiatal esophagectomy for esophageal cancer includes mediastinoscopic and laparoscopic transhiatal esophagectomy. It is inadequate in both two techniques. It is impossible to dissect the lower esophagus with single mediastinoscopy or the upper and middle esophagus with single laparoscopy. We use mediastinoscopy combined with laparoscopy to dissect the whole esophagus and stomach including lymph node dissection. In addition, laparoscopic gastric mobilization leads to less trauma than an open gastroplasty.Methods40 cases of video-assisted mediastinoscopic transhiatal esophagectomy were performed and divided into two groups.32 patients were received surgical therapy of single mediastinoscopic esophagectomy with open gastroplasty in group A, while 8 patients were received surgical therapy of mediastinoscopic esophagectomy combined with laparoscopic lower esophageal and gastric dissection in group B. The perioperative complications were recorded.ResultsVideo-assisted mediastinoscopic transhiatal esophagectomy was performed successfully both in group A and B. It suggested that mediastinoscopy combined with laparoscopy be better than single mediastinoscopy because of less blood loss, less pain, shorter ICU stay and complete lower mediastinal lymph nodes resection.ConclusionsVideo-assisted mediastinoscopic transhiatal esophagectomy combined with laparoscopy is a safe and minimally invasive technique with whole esophagus and mediastinal lymph node dissection in the clear visualization of the mediastinum, reducing the abdominal trauma.

Tissue engineering rib with the incorporation of biodegradable polymer cage and BMSCs/decalcified bone: an experimental study in a canine model

BackgroundThe reconstruction of large bone defects, including rib defects, remains a challenge for surgeons. In this study, we used biodegradable polydioxanone (PDO) cages to tissue engineer ribs for the reconstruction of 4cm-long costal defects.MethodsPDO sutures were used to weave 6cm long and 1cm diameter cages. Demineralized bone matrix (DBM) which is a xenograft was molded into cuboids and seeded with second passage bone marrow mesenchymal stem cells (BMSCs) that had been osteogenically induced. Two DBM cuboids seeded with BMSCs were put into the PDO cage and used to reconstruct the costal defects. Radiographic examination including 3D reconstruction, histologic examination and mechanical test was performed after 24 postoperative weeks.ResultsAll the experimental subjects survived. In all groups, the PDO cage had completely degraded after 24 weeks and been replaced by fibrous tissue. Better shape and radian were achieved in PDO cages filled with DBM and BMSCs than in the other two groups (cages alone, or cages filled with acellular DBM cuboids). When the repaired ribs were subjected to an outer force, the ribs in the PDO cage/DBMs/BMSCs group kept their original shape while ribs in the other two groups deformed. In the PDO cage/DBMs/BMSCs groups, we also observed bony union at all the construct interfaces while there was no bony union observed in the other two groups. This result was also confirmed by radiographic and histologic examination.ConclusionsThis study demonstrates that biodegradable PDO cage in combination with two short BMSCs/DBM cuboids can repair large rib defects. The satisfactory repair rate suggests that this might be a feasible approach for large bone repair.

A portable thoracic closed drainage instrument for hemopneumothorax.

BACKGROUND: Hemopneumothorax is a common sequelae of traumatic thoracic injury. The most effective treatment of this condition is thoracic drainage. Despite the common occurrence of this condition, available instruments are difficult to use emergently, particularly when large amounts of patients need to be drained. In the present experiment, a newly designed chest tube and thoracic closed drainage package is described and preliminarily evaluated with the goal to improve the treatment of traumatic hemopneumothorax. METHOD: Twenty canines were divided into two groups. In one group, the newly designed thoracic closed drainage package was used, whereas in the other group a currently available chest tube and bottle were used. Drainage test, ultrasound examination, flushing test, and tension test were performed to evaluate the effectiveness of the drainage package. RESULTS: We found that the newly-designed drainage tube is as effective as the common tube when evaluated using all of the chosen methods. In addition, the package is very lightweight and portable. CONCLUSION: The newly-designed thoracic drainage package is very effective in the emergency treatment of thoracic trauma and may be more suitable for the emergency treatment of hemopneumothorax.