Prefabricated flaps for bone reconstructive surgery.

Contains fulltext : 58775.pdf (publisher's version ) (Open Access)Tissue engineering of bone could help minimise donor site defects of conventional bone flaps like the fibula, iliac crest, radius and scapula. First a review is given on the literature of donor site morbidity of these flaps. Then the use of MRI is investigated for longitudinal study of ectopic bone formation in a rat model with demineralised bone matrix in a subcutaneous site. The results of this study show that in vivo MRI is well suited to assess bone formation larger than 0.5 mm in diameter and to monitor the complete three-dimensional shape of the newly formed bone in a noninvasive manner. In the third chapter it is concluded that in vivo MRI proves to be a reliable method for monitoring ectopic bone formation in a rat model with DBM in a muscle flap, while in vivo DEXA was unable to detect the implants. Furthermore, in vivo MRA proves to be a very useful technique for studying the circulation of muscle flaps in this animal model. In chapter four it is concluded that enlargement of the surface area by morsellizing DBM implants in a rat model is not an important factor in bone forming capacity. In chapter five, the aim of the study is to investigate the influence of the carrier in a cell-based bone regeneration approach, whereby we hypothesize that CaP ceramic implants will induce more bone formation than Ti-fiber implants. Our hypothesis is confirmed. In chapter six the hypothesis that a muscle recipient site could favor bone formation in a cell-based bone graft substitute compared to a subcutaneous recipient site due to the higher vascularity of muscle tissue, could not be confirmed. In the last chapter the influence of a microsurgical anastomosis on a prefabricated flap is investigated: We conclude that in a rat model viable microsurgical bone flaps can be obtained by using a cell-based tissue engineering approach.KUN Katholieke Universiteit Nijmegen, 7 oktober 2004Promotores : Spauwen, P.H.M., Jansen, J.A.161, [14] p

Surgical treatment of hemangiomas and vascular malformations in functional areas.

Contains fulltext : 23059___.PDF (publisher's version ) (Open Access

The nasolabial fold as potential vascular receptor site: an anatomic study.

Contains fulltext : 81219.pdf (publisher's version ) (Open Access

Rapidly progressive soft tissue infections.

Contains fulltext : 50352.pdf (publisher's version ) (Closed access

Hypopharyngeal reconstruction with an anterolateral thigh flap after laryngopharyngeal resection: results of a retrospective study on 20 patients.

Contains fulltext : 88259.pdf (publisher's version ) (Closed access)The aim of this retrospective study is to evaluate short- and long-term postoperative morbidity and mortality of hypopharyngeal resection and reconstruction. Patients with laryngopharyngeal malignancies were treated with laryngopharyngectomy and the resulting defect was reconstructed with an anterolateral thigh flap. The study group consisted of 20 patients with one or more primary hypopharyngeal carcinomas or a relapse of this tumour. All patients were diagnosed and operated in the University Medical Center between February 2000 and July 2007. Data were collected from the clinical medical files of the departments of plastic surgery and oto-rhino-laryngology. The dietetic and speech therapy files were used as well. To study the quality of life, the Dutch version of the University of Washington Quality of Life questionnaire was sent to all surviving patients. The microsurgical reconstructions were 100% successful. Fifteen patients (75.0%) died during the follow-up period; the 5-year overall survival was 20%. Complications such as post-surgical fistulas and strictures requiring surgical intervention were found in five (25.0%) and six patients (30.0%), respectively. Other post-surgical complications such as wound dehiscence were seen in two patients (10.0%). The incidence of donor-site complications at the thigh was very low. No significant relationship was found among preoperative patients' characteristics like age, gender, preoperative radiotherapy, the TNM (tumour, node, metastasis) classification of the tumour and the risk of post-surgical complications. The number and/or the severity of the complications were not significantly associated with the duration of surgery or ischaemia time. In our view, surgery is a good option in the treatment of these patients. Although curative treatment is the best outcome, a satisfactory palliation in itself can be a justification for this type of surgery. Although only seven patients were able to answer the QOL questionnaire, the positive judgements of these patients support this view point.1 juni 201

Donor-site complications in vascularized bone flap surgery.

Microvascular osteocutaneous free flaps have given reconstructive surgeons a powerful tool in the reconstruction of composite defects in head and neck surgery. Radial forearm, scapula, iliac crest, and fibula flaps have been used extensively in mandibular reconstruction. The inevitable donor-site morbidity of these osteocutaneous flaps has received less attention than the reconstructive advantages. We have reviewed the literature for each type of flap to determine the kind, incidence, and consequences of flap associated morbidity. In the future, tissue-engineered prefabricated free flaps might play an important role

Ectopic bone formation in rats: the importance of the carrier.

Contains fulltext : 48660.pdf (publisher's version ) (Closed access)Much research has been done to develop the ideal bone graft substitute (BGS). One approach to develop this ideal BGS is the use of growth factors, but for this approach osteoprogenitor cells are needed at the site of reconstruction. An alternative is a cell-based approach, where enough cells are provided to form bone in a carrier material. In previous studies of our group, titanium (Ti) carriers have been used, because of the excellent mechanical properties and the bone-compatibility of this material. On the other hand, calcium phosphate (CaP) ceramics are known for their excellent osteoconductivity. The aim of this study is to investigate the influence of the carrier in a cell-based bone regeneration approach, whereby we hypothesize that CaP-ceramic implants will induce more bone formation than Ti-fiber implants, in the same animal model as our previous experiment. Ti-fiber mesh implants and ceramic implants were seeded with rat bone marrow cells (RBM) and implanted subcutaneously. Histological analysis after one, three and six weeks showed differences in the way of bone formation in the two groups: bone appeared to grow from the center to the periphery of the implant in the titanium group, while bone formation in the ceramic group occurred through the whole implant. Histomorphometrical analysis after one week showed very limited bone formation for both the titanium and ceramic group. At three weeks, the amount of bone formation was increased till about 10% for the titanium group and 18% for the ceramic group. No significant difference between the two groups could be observed. In the six week group, the bone formation was 6% (Ti) and 23% (CaP), respectively (P < 0.001). Further, bone formation started earlier in the CaP-ceramic scaffolds than in the Ti scaffolds. Our hypothesis could be confirmed: ceramic implants induce more bone formation than titanium implants