Soft and Firm Alloplastic Implants in Rhinoplasty: Why, When and How to Use Them: A Review of 311 Cases.

BACKGROUND: Modern rhinoplasty is not just a reduction procedure. An optimal nasal esthetic result occasionally requires augmenting the nasal tip, the dorsum or the lateral wall with autografts or alloplasts. A large number of nasal implant types have been reported in the medical literature. OBJECTIVE: The goal of this article is to demystify the role and indications of nasal implants in rhinoplasty. As well, it offers both the novice and experienced nasal surgeon a basic, simplified and organized approach to the use of soft and firm nasal implants in rhinoplasty. METHODS: This article presents the authors experience with 311 rhinoplasties using both soft and firm alloplastic implants. The indications for both types of alloplasts are discussed, the surgical technique detailed and the outcomes analyzed. RESULTS: A total of 311 nasal implant cases were reviewed. This series revealed a low incidence of postoperative infection (5.57% for soft implants and 0.1% for the firm ones). The revision rate was 2.7% for the soft implants group and 7.1% for the firm implants group. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Hydroxyapatite coating enhances polyethylene terephthalate artificial ligament graft osseointegration in the bone tunnel.

The purpose of this study was to investigate whether hydroxyapatite (HAp) coating could induce polyethylene terephthalate (PET) artificial ligament graft osseointegration in the bone tunnel. Twenty-four New Zealand white rabbits underwent artificial ligament graft transplantation in bilateral proximal tibia tunnels. One limb was implanted with HAp-coated PET graft, and the contralateral limb was implanted with non-HAp-coated PET graft as control. The rabbits were randomly sacrificed at four and eight weeks after surgery. The loads to failure of the experimental group at eight weeks were significantly higher than those of the control group (p = 0.0057). Histologically, application of HAp coating induced new bone formation between graft and bone at eight weeks compared with the controls. Real-time polymerase chain reaction examination revealed significantly elevated messenger ribonucleic acid expression levels of osteopontin and collagen I in the grafts of the HAp group compared with the controls at four weeks (p < 0.05). The study has shown that HAp coating on the PET artificial ligament surface has a positive effect in the induction of artificial ligament osseointegration within the bone tunnel.

[The use of silver/collagen coated vascular prostheses in the treatment of critical limbs ischemia]. / Stosowanie protez naczyniowych impregnowanych solami srebra i uszczelnianych kolagenem w krytycznym niedokrwieniu konczyn dolnych.

Critical lower limb ischemia is a term used to define those patients with chronic ischemic pain at rest, ulcerations or limb necrosis caused by confirmed atherosclerotic lesions of the arteries. In this paper to evaluate of the clinical usefulness of silver coated prostheses in critical lower limb ischemia was presented. The use of the vascular artificial prostheses (dacron, dacron with velour, dacron albumin coated, polytetrafluoroethylene, dacron gentamicin/ryfampicin coated) in the critical ischemia limbs threatened is her contagion. In cases of potentially threatened a contagion is indicated the use of vascular prostheses about enlarged resistance on the contagion, e.g. the silver/collagen coated prosthesis. A foundation of the use of such prostheses are antibacterial proprieties of polyester fibers salts of the silver. An aim of many works is estimation of healing of the silver prostheses of grafted in lower limb at ill with the critical ischemia where infecting of the synthetic material is extremely probable. The healing of the silver prosthesis rated is most often at the use of the scintigraphy with Technetium 99. One attends that such research will make possible the estimation of the usefulness of the vascular silver prostheses in reconstructive operations in the vascular surgery, particularly in cases threatened with the infection of used synthetic material.

Role of plasma fibronectin in the foreign body response to biomaterials.

Host responses to biomaterials control the biological performance of implanted medical devices. Upon implantation, synthetic materials adsorb biomolecules, which trigger an inflammatory cascade comprising coagulation, leukocyte recruitment/adhesion, and foreign body reaction. The foreign body reaction and ensuing fibrous encapsulation severely limit the in vivo performance of numerous biomedical devices. While it is well established that plasma fibrinogen and secreted cytokines modulate leukocyte recruitment and maturation into foreign body giant cells, mediators of chronic inflammation and fibrous encapsulation of implanted biomaterials remain poorly understood. Using plasma fibronectin (pFN) conditional knock-out mice, we demonstrate that pFN modulates the foreign body response to polyethylene terephthalate disks implanted subcutaneously. Fibrous collagenous capsules were two-fold thicker in mice depleted of pFN compared to controls. In contrast, deletion of pFN did not alter acute leukocyte recruitment to the biomaterial, indicating that pFN modulates chronic fibrotic responses. The number of foreign body giant cells associated with the implant was three times higher in the absence of pFN while macrophage numbers were not different, suggesting that pFN regulates the formation of biomaterial-associated foreign body giant cells. Interestingly, cellular FN (cFN) was present in the capsules of both normal and pFN-depleted mice, suggesting that cFN could not compensate for the loss of pFN. These results implicate pFN in the host response to implanted materials and identify a potential target for therapeutic intervention to enhance the biological performance of biomedical devices.

Stable ciliary activity in human nasal epithelial cells grown in a perfusion system.

PURPOSE: Explore the usefulness of a perfusion system in order to establish human nasal epithelial cell cultures suitable for long-term in vitro ciliary beat frequency (CBF) and cilio-toxicity studies. METHODS: The cells were obtained by protease digestion of nasal biopsy material. The cells were plated at a density of 0.8-1 x 10(6)/cm2 on Vitrogen-coated polyethylene terephthalate membranes, and cultured under submerged conditions in a CO2 incubator or in a perfusion system (initiated on days 8-9 after plating). The CBF was determined at 24.1 +/- 0.8 degrees C by a computerized microscope photometry system. The morphology of the cultured cells was characterized by transmission electron microscopy (TEM). RESULTS: Under CO2 incubator culture conditions, stable ciliary activity was expressed and maintained from day 2 to day 24. Under perfusion system culture conditions, the CBF (mean+/-S.D., n = 4) amounted to 8.4 +/- 0.9 and 8.8 +/- 0.4 Hz on days 7 and 14, respectively. These values were lower as compared to the corresponding CBF obtained in the CO2 incubator cultures (9.5 +/- 0.6 and 9.9 +/- 1.0 Hz, respectively). Reference cilio-stimulatory (glycocholate) and cilio-inhibitory (chlorocresol) compounds were used to assess CBF reactivity. In the CO2 incubator and 7- and 14-days perfusion system cultures, glycocholate (0.5%) showed a reversible cilio-stimulatory effect of 23, 26 and 21%, respectively, while chlorocresol (0.005%) exerted a reversible cilio-inhibitory effect of 36, 40 and 36%, respectively. TEM revealed polarized cuboidal to columnar epithelial morphology, with well-differentiated ciliated cells under CO2 and perfusion system conditions (up to day 23). CONCLUSION: Culturing human nasal epithelial cells on Vitrogen-coated polyethylene terephthalate membranes in submerged conditions in a CO2 incubator and in a perfusion system offers the possibility for long-term preservation (up to 22-24 days) of stable and reactive CBF in vitro.

Acceleration of aneurysm healing by controlled release of basic fibroblast growth factor with the use of polyethylene terephthalate fiber coils coated with gelatin hydrogel.

OBJECTIVE: The aims of this study were to develop an endovascular delivery system containing gelatin hydrogels for the controlled release of basic fibroblast growth factor (bFGF) with the use of polyethylene terephthalate fiber coils and to analyze whether such a system would promote healing in an experimental aneurysm. METHODS: Carotid aneurysms were constructed in 66 rabbits with venous pouches. The polyethylene terephthalate fiber coils coated with and without gelatin hydrogels with different water volumes containing 0, 10, 50, and 100 microg bFGF were implanted into the aneurysms. Histological specimens were harvested at 1, 2, and 3 weeks and at 6 months after implantation. A histological evaluation was performed while the area occupied by the fibrosis in the aneurysms was calculated. RESULTS: Three weeks after the application of the coils coated with gelatin hydrogels (95 vol%) containing 100 microg bFGF, all aneurysmal orifices were completely closed with neointima. When the coils coated with gelatin hydrogel (98 vol%) containing 100 microg bFGF were used, the orifices in three of the six aneurysms were closed. In contrast, the orifice of the aneurysm was not obliterated when other materials were used. After implanting the coils coated with gelatin hydrogel (95 vol%) containing 100 microg bFGF more than 3 weeks later, the aneurysm was histologically suffused with fibrous tissue, and the area occupied by fibrosis was significantly larger than that observed in the other groups (P < 0.05). CONCLUSION: Local, controlled release of sufficient amounts of bFGF with polyethylene terephthalate fiber coils coated with gelatin hydrogel accelerated the organization of aneurysms.

Stability aspects of salmon calcitonin entrapped in poly(ether-ester) sustained release systems.

Poly(ether-ester)s composed of hydrophilic poly(ethylene glycol)-terephthalate (PEGT) blocks and hydrophobic poly(butylene terephthalate) (PBT) blocks were studied as matrix for the controlled release of calcitonin. Salmon calcitonin loaded PEGT/PBT films were prepared from water-in-oil emulsions. The initial calcitonin release rate could be tailored by the copolymer composition, but incomplete release of calcitonin was observed. FTIR measurements indicated aggregation of calcitonin in the matrix, which was not due to the preparation method of the matrices, but due to the instability of calcitonin in an aqueous environment. Release experiments showed the susceptibility of calcitonin towards the composition of the release medium, in particular to the presence of metal ions. With increasing amount of sodium ions, a decrease in the total amount of released calcitonin was observed due to enhanced aggregation. The calcitonin had to be stabilized in the matrix to prevent aggregation. Incorporation of sodium dodecyl sulphate (SDS) as a stabilizer in PEGT/PBT matrices increased the percentage of calcitonin released, but could not avoid aggregation on a longer term.