Treatment of postreconstructive collapsed nasal ala with a costal cartilage graft

A technique to restore the skeletal support of the postreconstruction collapsed ala is proposed. This makes use of the elastic characteristic of costal cartilage to provide a natural spring to elevate the ala and thereby enlarge the nostril. Three illustrative cases are described.     

In situ split costal cartilage graft harvesting through a small incision using a gouge

A costal cartilage graft is one of the most useful materials in reconstructive plastic surgery. In this article, a technique of in situ split costal cartilage graft harvesting through a small incision (2 to 3 cm) using a gouge is described. The technique used has many advantages: it is a simple technique, is easy to learn, and can be performed quickly through a small incision. By avoiding complete costal cartilage graft harvesting, the associated potential complications such as pleural perforation, chest wall deformities, long-lasting postoperative pain, and incisional scar length are reduced. This technique will be useful in selected cases for which a complete block of costal cartilage graft is not needed.     

Dielectric characterization of costal cartilage chondrocytes

Background

Chondrocytes respond to biomechanical and bioelectrochemical stimuli by secreting appropriate extracellular matrix proteins that enable the tissue to withstand the large forces it experiences. Although biomechanical aspects of cartilage are well described, little is known of the bioelectrochemical responses. The focus of this study is to identify bioelectrical characteristics of human costal cartilage cells using dielectric spectroscopy.

Methods

Dielectric spectroscopy allows non-invasive probing of biological cells. An in house computer program is developed to extract dielectric properties of human costal cartilage cells from raw cell suspension impedance data measured by a microfluidic device. The dielectric properties of chondrocytes are compared with other cell types in order to comparatively assess the electrical nature of chondrocytes.

Results

The results suggest that electrical cell membrane characteristics of chondrocyte cells are close to cardiomyoblast cells, cells known to possess an array of active ion channels. The blocking effect of the non-specific ion channel blocker gadolinium is tested on chondrocytes with a significant reduction in both membrane capacitance and conductance.

Conclusions

We have utilized a microfluidic chamber to mimic biomechanical events through changes in bioelectrochemistry and described the dielectric properties of chondrocytes to be closer to cells derived from electrically excitably tissues.

General significance

The study describes dielectric characterization of human costal chondrocyte cells using physical tools, where results and methodology can be used to identify potential anomalies in bioelectrochemical responses that may lead to cartilage disorders.     

An investigation of ageing in human costal cartilage

Summary Changes in human costal cartilage with increasing age (2–81 years) have been studied in the optical and electron microscope using routine and histochemical techniques.Concurrent with increasing age, chondrocytes undergo degeneration which is characterized initially by the accumulation of lipidic material within cells and, subsequently, by the formation of a halo around degenerating chondrocytes. The halo material is composed of electron dense bodies, amorphous material, and collagen fibrils. Both electron dense bodies and the amorphous material are of cellular origin and they have similar histochemical responses.Using histochemical techniques in the optical and in the electron microscope, it has been shown that chondroitin sulfate decreases with increasing age, while a hyaluronidase resistant material (presumably keratan sulfate) increases, initially in the central zone, and subsequently in the peripheral zones. Hyaluronidase resistant material is minute or absent in the central zone of aged cartilage.The genesis of collagen fibrils progresses from thin unbanded collagen-like fibrils in the pericellular lacunae of chondrocytes in young specimens to thick fibrils (sometimes in excess of 0.5 ) with a period of 640 Å in ageing cartilage. Aggregation of collagen fibrils seems to be related at least initially to the preponderance of matrix granules and beaded filaments which have been shown to originate intracellularly in vacuoles formed in degenerating mitochondria. Both of these structures contain glycosaminoglycans and, with increasing age, glycosaminoglycans decrease while collagen fibrils aggregate. In old age, the amorphous material, and possibly the content of disrupting electron dense bodies, seem to give origin to some collagen fibrils. This and other mechanisms of formation of collagen fibrils have been observed and they are discussed.Calcification of the matrix increases with increasing age and this agrees with previous findings.Supported by grants from the Italian National Research Council. — The authors are indebted to Miss Giuliana Silvestrini and to Mr. Lucio Virgilii for their expert and extensive technical assistance. — To Dr. A. Ascenzi, Director 1° Istituto di Anatomia e Istologia Patologica, and to Dr. C. Cavallero, Director, 2° Istituto di Anatomia e Istologia Patologica, Università di Roma, the senior author would like to express his appreciation for the use of equipment and facilities pursuant to this investigation, while on sabbatical leave from the University of California, Irvine, College of Medicine. — We wish to extend our thanks to the Italian National Research Council for supporting this study.On sabbatical leave from the University of California, Irvine, College of Medicine.     

The Turkish delight: a pliable graft for rhinoplasty

In nose surgery, carved or crushed cartilage used as a graft has some disadvantages, chiefly that it may be perceptible through the nasal skin after tissue resolution is complete. To overcome these problems and to obtain a smoother surface, the authors initiated the use of Surgicel-wrapped diced cartilage. This innovative technique has been used by the authors on 2365 patients over the past 10 years: in 165 patients with traumatic nasal deformity, in 350 patients with postrhinoplasty deformity, and in 1850 patients during primary rhinoplasty. The highlights of the surgical procedure include harvested cartilage (septal, alar, conchal, and sometimes costal) cut in pieces of 0.5 to 1 mm using a no. 11 blade. The fine-textured cartilage mass is then wrapped in one layer of Surgicel and moistened with an antibiotic (rifamycin). The graft is then molded into a cylindrical form and inserted under the dorsal nasal skin. In the lateral wall and tip of the nose, some overcorrection is performed depending on the type of deformity. When the mucosal stitching is complete, this graft can be externally molded, like plasticine, under the dorsal skin. In cases of mild-to-moderate nasal depression, septal and conchal cartilages are used in the same manner to augment the nasal dorsum with consistently effective and durable results. In cases with more severe defects of the nose, costal cartilage is necessary to correct both the length of the nose and the projection of the columella. In patients with recurrent deviation of the nasal bridge, this technique provided a simple solution to the problem. After overexcision of the dorsal part of deviated septal cartilage and insertion of Surgicel-wrapped diced cartilage, a straight nose was obtained in all patients with no recurrence (follow-up of 1 to 10 years). The technique also proved to be highly effective in primary rhinoplasties to camouflage bone irregularities after hump removal in patients with thin nasal skin and/or in cases when excessive hump removal was performed. As a complication, in six patients early postoperative swelling was more than usual. In 16 patients, overcorrection was persistent owing to fibrosis, and in 11 patients resorption was excessive beyond the expected amount. A histologic evaluation was possible in 16 patients, 3, 6, and 12 months postoperatively, by removing thin slices of excess cartilage from the dorsum of the nose during touch-up surgery. This graft showed a mosaic-type alignment of graft cartilage with fibrous tissue connection among the fragments. In conclusion, this type of graft is very easy to apply, because a plasticine-like material is obtained that can be molded with the fingers, giving a smooth surface with desirable form and long-lasting results in all cases. The favorable results obtained by this technique have led the authors to use Surgicel-wrapped diced cartilage routinely in all types of rhinoplasty.     

Turnover of proteoglycans in guinea pig costal cartilage

The turnover in vivo of proteoglycans of guinea pig costal cartilage was investigated using Na₂³⁵SO₄ as precursor. Proteoglycans were extracted with guanidine · HCl, at both low and high ionic strength, and purified and fractionated by ultracentrifugation in CsCl gradients under associative and dissociative conditions. The results suggest that the sulfate is incorporated into macromolecules of at least two major metabolic pools with half-lives of about 3 days and about 60–70 days, respectively. Molecules with a fast turnover were enriched in the low ionic strength extracts and in fractions containing small, nonaggregated proteoglycans. No substantial evidence was found for a precursor-product relationship between different fractions.     

The effect of calcification on the structural mechanics of the costal cartilage

The costal cartilage often undergoes progressive calcification with age. This study sought to investigate the effects of calcification on the structural mechanics of whole costal cartilage segments. Models were developed for five costal cartilage specimens, including representations of the cartilage, the perichondrium, calcification, and segments of the rib and sternum. The material properties of the cartilage were determined through indentation testing; the properties of the perichondrium were determined through optimisation against structural experiments. The calcified regions were then expanded or shrunk to develop five different sensitivity analysis models for each. Increasing the relative volume of calcification from 0% to 24% of the cartilage volume increased the stiffness of the costal cartilage segments by a factor of 2.3–3.8. These results suggest that calcification may have a substantial effect on the stiffness of the costal cartilage which should be considered when modelling the chest, especially if age is a factor.     

A new method of reconstruction for pectus excavatum that preserves blood supply and costal cartilage.

We began in 1982 to use a modified Ravitch procedure that preserves the blood supply to the sternum to correct funnel chest deformities, but there were some problems such as postoperative paradoxical respiration, chest wall irregularity, and palpable heart beat. To resolve these problems, the concept of Jensen's procedure was incorporated into the authors' previous method. In Jensen's method, only a small portion of the deformed cartilages is resected, and almost all of them are preserved. A preformed stainless steel strut is used for chest wall stabilization. The authors preserved the costal cartilages in a manner similar to Jensen's, but the anterior chest wall was stabilized with miniplates and Kirschner wires instead of a large retrosternal strut. The xiphoid process with the lower end of the sternum was detached and moved cephalad. None of the patients developed respiratory failure postoperatively. Although the follow-up periods were short, satisfactory results were obtained with no recurrence of the deformities. The main advantages of our procedure are (1) basic blood supply to the chest wall is preserved, (2) stability of corrected chest wall is maintained with miniplates and Kirschner wires without a large metallic strut, and (3) preserved costal cartilages make the chest wall rigid and the incidence of respiratory failure low. We conclude that this method is simple and produces satisfactory results with a rigid chest wall.     

Compositional changes of the xiphoid process and costal cartilage with aging

Because zinc attenuates endothelial cell dysfunction that proceeds atherosclerosis, depressed zinc status may be involved in the initiation of endothelial dysfunction. However, before recommending a zinc-enriched diet to reduce the risks for atherosclerosis, the effect of excess zinc on endothelial cell functions in normozincemic status should be known. Therefore, in this study, the effect of dietary zinc on normal endothelial cell functions in animals subjected to a diet containing 334±58 ppm zinc for 30 d was studied to see whether supplemented zinc has an effect on endothelial cells. Despite a slight increase in blood zinc, unaltered aortic and kidney zinc contents were associated with unchanged blood pressure in rats subjected to a zinc-enriched diet. Increased basal nitric oxide and prostacyclin were accompanied by a normal response to phenylephrine. Dietary zinc influenced neither endothelial-dependent nor endothelial-independent relaxations significantly. However, it elevated the share of M1-type cholinoceptor response as well as dilator prostaglandin release, which seems to be nitric oxide dependent. There was a strong correlation (r=0.826, p<0.05) between M1-type cholinoceptor response and prostacyclin release in zinc-treated rings. These results suggested that zinc ions increases M1-mediated prostacyclin release in normal endothelial cells without altering intracellular pathways.