INTRODUÇÃO: A área da seccção externa da narina é a parte inferior da válvula nasal externa que é o primeiro obstáculo ao fluxo de ar. Existem dúvidas e controvérsias em relação a eficácia de tratamentos cirúrgicos nessa região do nariz durante a rinoplastia. Neste estudo, compararam-se em cadáveres o uso do enxerto de reforço alar modificado de cartilagem septal e costal para analisar o aumento da área seccional externa narinária. MÉTODOS: Trinta narinas de cadáveres foram dissecados no Serviço de Verificação de Óbito da Capital- Universidade de São Paulo. A escolha dos cadáveres foi aleatória (9 mulheres e 6 homens) excluíndo-se os casos com lesão deformante nasal ou doença intra-nasal. Todos os enxertos septais e costais apresentavam as mesmas dimensões (30 x 5 x 1 mm) e foram inseridos acima do ramo lateral das cartilagens alares de maneira aleatória. A seguir, realizaram-se fotos padronizadas e mensurações das 90 áreas seccionais externas de narina com o programa Autocad®; 30 antes de qualquer procedimento; 60 após a inclusão de enxertos (30 usando cartilagem costal e 30 usando cartilagem septal). A análise estatística foi feita com um modelo de medidas repetidas e ANOVA (análise de variância) para a variável área. A comparação das médias foi feita pelo método de Tukey, sendo o coeficiente de confiança global de 95%. RESULTADOS: A área seccional externa da narina sem tratamento, com inclusão de enxerto de reforço alar modificado septal e costal é, respectivamente, 0,76 cm2, 0,85 cm2 (aumento de 11,8%) e 0,91 cm2 (aumento de 19,7%). CONCLUSÃO: O enxerto de reforço alar modificado de costela é estatisticamente mais efetivo que o enxerto de reforço alar modificado de septo para aumentar a área de secção externa da narina / INTRODUCTION: The nostril cross-sectional area (bottom of the external nasal valve) presents the first obstacle to airflow. There are doubts and controversies regarding the effectiveness of surgical treatments in this region of the nose during a rhinoplasty. In this study, we have tested two modified strategies for alar reinforcement, one using a cartilage graft from the nasal septum and the other using rib cartilage, to analyze and compare their effectiveness in augmenting nostril cross-sectional area. METHODS: Thirty corpses nostrils were dissected in the Division of Postmortem Inspection at the University of São Paulo. Corpses were chosen at random (9 women and 6 men) excluding those with deforming nasal injury or intra-nasal disease. All nasal septum and rib grafts had the same dimensions (30 x 5 x 1 mm) and were inserted randomly above the lateral crura of the alar cartilages. Then, a total of 90 standardized photographs were taken to measure nostril cross-sectional area using the Autocad® program; one per nostril on all 15 cadavers, at three separate intervals. Thirty photos were taken prior to any procedure being performed, and 60 after the insertion in each nostril, of the two different types of cartilage grafts. After one graft was tested, it was removed and replaced with the other type. The order of the procedures was randomized. Statistical analyses were conducted using a model for repeated measures and ANOVA for the variable area. The comparison of means was done with Tukeys method and a 95% confidence coefficient. RESULTS: The nostril cross-sectional area before treatment, after modified alar reinforcement using septum cartilage graft, and after modified alar reinforcement using rib graft were 0,76 cm2, 0,85 cm2 (increase of 11,8%) and 0,91 cm2 (increase 19.7%), respectively. CONCLUSION: The modified alar reinforcement using grafts of rib cartilage is statistically more effective than the modified alar reinforcement using grafts of nasal septum in increasing the nostril cross-sectional area

<p>Infrainguinal bypass grafting is an established method in the treatment of patients with femoropopliteal and crural occlusive disease leading to critical lower limb ischaemia (CLI). However, complications related to surgical procedure are not negligible and percutaneous transluminal angioplasty (PTA) has emerged as an alternative. The present thesis covers some aspects of infrainguinal PTA in patients with chronic severe lower limb ischaemia.</p><p>The records of 217 patients undergoing 272 PTA procedures at various infrainguinal arterial segments were analysed. The indication for intervention was subcritical ischaemia in 76 limbs and critical ischaemia in 177 limbs. The role of duplex ultrasound examination in the selection of patients for PTA was retrospectively evaluated following a prospective validation of the method against angiography.</p><p>A technically successful PTA was achieved in 89%. The overall 30-day mortality was 2.7%. No patient underwent amputation directly related to failed PTA. The primary success rates at 12 and 60 months following femoropopliteal PTA were 40% and 27% compared, to 51% and 36% in limbs undergoing crural artery PTA. Primary success rate in limbs with SFA occlusion longer than 5 cm was only 12% after 5 years, compared to 32% if the occlusion was equal or less than 5 cm in length (p<0.01). In patients undergoing distal PTA through patent infrainguinal grafts, the primary and primary assisted patency rates at 3 years were 32% and 53%, respectively. The sensitivity of duplex scanning in the selection of lesions for PTA was less satisfactory in the popliteal and crural arteries compared to the superficial femoral arteries.</p><p>In conclusion, the results of infrainguinal PTA performed for treatment of subcritical or CLI seemed to be inferior to the results of surgical interventions reported in the literature. However, due to the fact that the PTA procedure does not preclude the performance of bypass grafting, it might be an alternative to surgical intervention in limbs with stenotic or short occlusive lesions.</p>

Infrainguinal bypass grafting is an established method in the treatment of patients with femoropopliteal and crural occlusive disease leading to critical lower limb ischaemia (CLI). However, complications related to surgical procedure are not negligible and percutaneous transluminal angioplasty (PTA) has emerged as an alternative. The present thesis covers some aspects of infrainguinal PTA in patients with chronic severe lower limb ischaemia. The records of 217 patients undergoing 272 PTA procedures at various infrainguinal arterial segments were analysed. The indication for intervention was subcritical ischaemia in 76 limbs and critical ischaemia in 177 limbs. The role of duplex ultrasound examination in the selection of patients for PTA was retrospectively evaluated following a prospective validation of the method against angiography. A technically successful PTA was achieved in 89%. The overall 30-day mortality was 2.7%. No patient underwent amputation directly related to failed PTA. The primary success rates at 12 and 60 months following femoropopliteal PTA were 40% and 27% compared, to 51% and 36% in limbs undergoing crural artery PTA. Primary success rate in limbs with SFA occlusion longer than 5 cm was only 12% after 5 years, compared to 32% if the occlusion was equal or less than 5 cm in length (p&lt;0.01). In patients undergoing distal PTA through patent infrainguinal grafts, the primary and primary assisted patency rates at 3 years were 32% and 53%, respectively. The sensitivity of duplex scanning in the selection of lesions for PTA was less satisfactory in the popliteal and crural arteries compared to the superficial femoral arteries. In conclusion, the results of infrainguinal PTA performed for treatment of subcritical or CLI seemed to be inferior to the results of surgical interventions reported in the literature. However, due to the fact that the PTA procedure does not preclude the performance of bypass grafting, it might be an alternative to surgical intervention in limbs with stenotic or short occlusive lesions.

The growing incidences of coronary artery bypass graft surgeries have triggered a need to engineer a viable small diameter blood vessel substitute. An ideal tissue engineered vascular graft should mimic the microenvironment of a native blood vessel, while providing the adequate compliance post-implantation. Current vascular graft technologies lack the ability to promote vascular ECM deposition, leading to a compliance mismatch and ultimately, graft failure. Hence, in order to engineer suitable vascular grafts, this thesis describes the synthesis and characterization of novel elastin mimetic peptides, EM-19 and EM-23, capable of promoting vascular ECM deposition within a poly(ethylene glycol) diacrylate (PEG-DA) hydrogel. By combining the material properties of a synthetic and bio-inspired polymer, a suitable microenvironment for cell growth and ECM deposition can be engineered, leading to improved compliance. As such, characterization of EM-19 and EM-23 was conducted in human vascular smooth muscle cell (SMC) cultures, and the peptides self-assembled with a growing elastic matrix. After grafting the peptides onto the surface of PEG-DA hydrogels, EM-23 increased SMC adhesion by 6000% over PEG-RGDS hydrogels, which have been the gold standard of cell adhesive PEG scaffolds. Moreover, EM-23 grafted surfaces were able to promote elastin deposition that was comparable to tissue cultured polystyrene (TCPS) surface even though TCPS had roughly 4.5 times more SMCs adhered. Once translated to a 3D model, EM-23 also stimulated increased elastin deposition and improved the mechanical strength of the scaffold over time. Moreover, degradation studies suggested that EM-23 may serve as a template that not only promotes ECM deposition, but also allows ECM remodeling over time. The characterization studies in this thesis suggest that this peptide is an extremely promising candidate for improving vascular ECM deposition within a synthetic substrate, and that it may be beneficial to incorporate EM-23 within polymeric scaffolds to engineer compliant vascular grafts.

No description available.

To be successful a tissue engineered small diameter blood vessel must be non-immunogenic, non-thrombogenic, have mechanical properties similar to native vessel and be vasoactive. The vascular media is responsible for the mechanical properties and the vasoactivity of the vessel. The collagen hydrogel approach has been long used and has many advantages, but has not yet achieved the mechanical integrity needed for implantation. No collagen-based tissue engineered vascular media has been shown to be vasoactive using culture techniques required to achieve the cell numbers needed to make a vascular graft. To study collagen synthesis, two model systems were used. Cells were seeded on top of an adsorbed collagen I or fibrin layer. Alternatively the cells were encapsulated in a collagen or fibrin hydrogel. Collagen I, decorin and biglycan synthesis was affected by both matrix type and presentation. After two weeks in culture the smooth muscle cells produce more type I collagen in the collagen based hydrogels then in the fibrin hydrogels and was used for further studies. The collagen based tissue engineered vascular media produced a consistent vasoactive response between two and eight weeks of culture. The smooth muscle cells have functional endothelin, kinin, adrenergic, serotonergic and purinergic receptors. The application of cyclic strain improves both the tissue strength and the contractile response. Use of transforming growth factor-β improved tissue strength, but reduced the contractile response. Transforming growth factor- β actually promoted a more contractile cell phenotype, but a stronger contractile force was required to overcome the thick compact collagen hydrogel and elicit a measurable contraction. This work adds to what is known about collagen-based tissue engineered vascular medias by identifying means of improving not only strength but vasoactivity. The trade-offs found between these two important characteristics are relevant to all tissue engineered medias.

Thesis (M.S.)--California Polytechnic State University, 2009. / Title from PDF title page; viewed on July 9, 2009. Major professor: Kristen O'Halloran Cardinal, Ph.D. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree [of] Master of Science in Engineering, with a Specialization in Biomedical Engineering." "April 2009." Includes bibliographical references (p. 114-121). Also available on microfiche.

Thesis (doctoral)--Lund University, 1993. / Added t.p. with thesis statement inserted.

Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. Teng Ma, Florida State University, College of Engineering, Dept. of Chemical and Biomedical Engineering. Title and description from dissertation home page (viewed Jan 12, 2005). Includes bibliographical references.

Thesis (doctoral)--Lund University, 1993. / Added t.p. with thesis statement inserted.