C.D.A. Verwoerd

The dual role of perichondrium in cartilage wound healing.

Cartilage structures from the head and neck possess a certain but limited capacity to heal after injury. This capacity is accredited to the perichondrium. In this study, the role of the inner (cambium) and the outer (fibrous) layers of the perichondrium in cartilage wound healing in vitro is investigated. For the first time, the possibility of selectively removing the outer perichondrium layer is presented. Using rabbit ears, three different conditions were created: cartilage explants with both perichondrium layers intact, cartilage explants with only the outer perichondrium layer dissected, and cartilage explants with both perichondrium layers removed. The explants were studied after 0, 3, 7, 14, and 21 days of in vitro culturing using histochemistry and immunohistochemistry for Ki-67, collagen type II, transforming growth factor beta 1 (TGFbeta1), and fibroblast growth factor 2 (FGF2). When both perichondrium layers were not disturbed, fibrous cells grew over the cut edges of the explants from day 3 of culture on. New cartilage formation was never observed in this condition. When only the outer perichondrium layer was dissected from the cartilage explants, new cartilage formation was observed around the whole explant at day 21. When both perichondrium layers were removed, no alterations were observed at the wound surfaces. The growth factors TGFbeta1 and FGF2 were expressed in the entire perichondrium immediately after explantation. The expression gradually decreased with time in culture. However, the expression of TGFbeta1 remained high in the outer perichondrium layer and the layer of cells growing over the explant. This indicates a role for TGFbeta1 in the enhancement of fibrous overgrowth during the cartilage wound-healing process. The results of this experimental in vitro study demonstrate the dual role of perichondrium in cartilage wound healing. On the one hand, the inner layer of the perichondrium, adjacent to the cartilage, provides (in time) cells for new cartilage formation. On the other hand, the outer layer rapidly produces fibrous overgrowth, preventing the good cartilage-to-cartilage connection necessary to restore the mechanical function of the structure.

Subglottic stenosis after endolaryngeal intubation in infants and children: Result of wound healing processes

OBJECTIVE To study the histopathology of subglottic stenosis in children of different ages after treatment during different periods of time, with or without laser application. Partial resection of the anterior cricoid with adhering stenotic subglottic area in the live young patient provides unique material for studying wound healing and scarring processes. METHODS 25 specimens obtained from partial cricotracheal resection (PCTR) in children, were histologically processed and stained with Haematoxylin and Eosin, Resorcin and Fuchsin (for elastic fibers), and immunohistochemical staining (for the presence of macrophages). RESULTS All specimens were found to have severe and sclerotic scarring with squamous metaplasia of the epithelium, loss of glands and elastic mantle fibers (tunica elastica), and dilation of the remaining glands with formation of cysts. Also, the cricoid cartilage was affected on the internal and external side, with irreversible loss of perichondrium on the inside and resorption by macrophages of cartilage on both sides. Detrimental effects of laser therapy were demonstrated in four cases. The normal intercellular matrix was completely destroyed and the number of chondrocytes in the cartilage structure diminished. CONCLUSION Wound healing after laryngeal injury is a process of intense restoration and reorganization of the various tissues involved. This process, however, does not guarantee complete repair. In the severe cases irreversible scarring has replaced normal tissues. There seems to be no direct relationship between the length of the post-lesional period, the age of the patient and the severity of the stenosis. When subglottic stenosis has developed and the majority of the tissues is replaced by dense fibrous tissue, PCTR is strongly indicated to achieve renewed patency of the airway.

Impact on Quality of Life of a Telemedicine System Supporting Head and Neck Cancer Patients: A Controlled Trial During the Postoperative Period at Home

OBJECTIVES Telemedicine applications carry the potential to enhance the quality of life of patients, but studies evaluating telemedicine applications are still scarce. The evidence regarding the effectiveness of telemedicine is limited and not yet conclusive. This study investigated whether telemedicine could be beneficial to the quality of life of cancer patients. DESIGN AND MEASUREMENTS Between 1999 and 2002, we conducted a prospective controlled trial evaluating the effects of a telemedicine application on the quality of life of patients with cancer involving the head and neck, using quality of life questionnaires that covered 22 quality of life parameters. All patients had undergone surgery for head and neck cancer at the Erasmus MC, a tertiary university hospital in The Netherlands. Patients in the intervention group were given access to an electronic health information support system for a period of six weeks, starting at discharge from the hospital. RESULTS In total, we included 145 patients in the control group and 39 in the intervention group. At 6 weeks, the end of the intervention, the intervention group had significantly improved QoL in 5 of the 22 studied parameters. Only one of these five quality of life parameters remained significantly different at 12 weeks. CONCLUSIONS This study adds to the sparse evidence that telemedicine may be beneficial for the quality of life of cancer patients.

Histologic study of the growth of the subglottis after interruption of the circular structure of the cricoid

In a previous study in growing rabbits it was demonstrated that after resection of a ventral part of the cricoid the lumen of the subglottic airway developed normal size during further growth up to the adult stage. Histologic investigations of these cases suggest that a subepithelial network of elastic fibres, ventrally suspended to the thyroid and the tracheal rings, ensures the airway lumen and prevents the development of a subglottic stenosis. Resection of a ventral part of the cricoid including the adjacent soft tissue lining of the airway causes an irreversible loss of the supporting elastic layer and the formation of scar tissue resulting in a stenosis. It was concluded that the larynx and trachea can be considered as an inner, elastic tube (= conus elasticus) lined with epithelium, suspended to an outer, segmented cartilaginous tube. At the level of the subglottis an intact conus elasticus is of more importance for the normal development of the airway lumen in young rabbits than an intact ventral half of the cricoid ring.

Stress and woundhealing of the cartilaginous nasal septum.

In the cartilaginous nasal septum of growing rabbits a stress is demonstrated, released by an incision perpendicular to the antero-posterior axis and rebuilt within a period of 3 weeks when the mechanical continuity of the septum is restored. The latter is the result of a process of woundhealing establishing a firm perichondrial side-to-side connection between the stumps.

Wound Healing of Autologous Implants in the Nasal Septal Cartilage

The cartilaginous nasal septum of the child is often involved in trauma or congenital deformation. In perspective of its role in postnatal growth of the midface, the wound healing of septal cartilage in reaction to various surgical procedures was studied in young rabbits. It was concluded that (1) elevation of mucoperichondrium does not induce significant histologic reactions in the septal cartilage and (2) the wound reaction of cut edges includes only a +/- 0.8-mm-deep zone and lasts no longer than 2 weeks, resulting in a stump, encapsulated by fibrous tissue. Reconnection of separated parts occurs 2 weeks after surgery, mostly by merging of the perichondrial layers. Reimplantation of resected cartilage does not lead to normalisation of septal growth. This is not caused by extensive necrosis, loss of morphological organisation or decreased growth potential of the reimplanted cartilage. The essential factor seems to be dislocation (duplication, angulation) of the implant versus the non-mobilised parts of the septum preventing the growth of the implant to contribute fully to the lengthening of the total septum.

Rhinosurgery in children: developmental and surgical aspects of the growing nose

The anatomy of the nasal skeleton in newborns and adults are not alike. The complete cartilaginous framework of the neonatal nose becomes partly and gradually ossified during the years of growth and is more vulnerable to trauma in that period. Injury in early youth may have large consequences for development and may result in a nasal deformity which will increase during growth and reach its peak during and after the adolescent growth spurt. To understand more of the underlying problems of nasal malformations and their surgical treatment (septorhinoplasty) these items became the focus of multiple animal studies in the last 40 years. The effects of surgery on the nasal septum varied considerably, seemingly depending on which experimental animal was used. In review, however, the very different techniques of the experimental surgery might be even more influential in this respect. Study of one of the larger series of experiments in young rabbits comprised skeletal measurements with statistical analysis, and microscopic observations of the tissues. The behaviour of hyaline cartilage of the human nose appeared to be comparable to that of other mammals. Cartilage, although resilient, can be easily fractured whereas its tendency to integrated healing is very low, even when the perichondrium has been saved. Also surgical procedures – like in septoplasty – may result in growth disturbances of the nasal skeleton like recurrent deviations or duplicature. Loss of cartilage, as might occur after a septum abscess, is never completely restored despite some cartilage regeneration. In this article experimental studies are reviewed and compared. Still there remains a lack of consensus in the literature concerning the developmental effects of rhinosurgry in children. Based on their observations in animals and a few clinical studies, mostly with small numbers of patients but with a long follow-up, the authors have compiled a list of guidelines to be considered before starting to perform surgery on the growing midface in children.

Differential effects of endolaryngeal trauma upon the growth of the subglottis.

In young rabbits (4-week-old) the growth of the subglottis was studied after an endolaryngeal soft tissue trauma. The injury induced the formation of a subglottic stenosis. In contrast to earlier observations on endolaryngeal trauma extending into the cricoid cartilage, the cricoid developed normally to the adult size and shape at 24 weeks. Similar to the earlier findings, the subepithelial layer showed considerable thickening as the result of formation of scar tissue, ectopic cartilage and fatty tissue with interruption of the elastic tunica (= conus elasticus). It was concluded that after endolaryngeal trauma in rabbits two types of subglottic stenosis can develop, determined by the depth of the injury.

Cartilage transformation in a composite graft of demineralized bovine bone matrix and ear perichondrium used in a child for the reconstruction of the nasal septum.

For the first time it was observed in a boy that a xenogenic implant of demineralized bovine bone matrix, enfolded in a pedicled flap of autogenic ear perichondrium, was transformed into autogenic cartilage. This new cartilage could be adequately used as a graft to bridge the cartilaginous defect of a nasal septum perforation. The defect was successfully closed by a technique employing four bipedicled mucosal advancement flaps of the septum and the nasal floor. The result of this pilot study, which is based on experiments in growing rabbits, appears to open the possibility to create de novo young and growing autogenic cartilage of substantial quantity in children, without the loss of the cartilage present.

Reconstruction of the growing cricoid with a composite graft of demineralized bovine bone and autogenous perichondrium; a comparative study in rabbits

In growing rabbits, the feasibility of a new type of composite graft for the reconstruction of defects in the cricoid ring is studied. This graft consists of Demineralized Bovine Bone matrix (DBBM) enfolded in a perichondrial flap. The cartilage formed in the DBBM by cells, derived from the perichondrium, is demonstrated to provide a valuable substitute for resected parts of the cricoid. A specific feature of this reconstruction is that it allows further growth and does not result in a secondary stenosis during later development.