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Biomedical subjects

D Gault

Publications and source records attributed to D Gault.

At least 19 recordsLinked to original sources

How we do it: BAHA positioning in patients with microtia requiring auricular reconstruction.

Keypoints * Bilateral microtia is a challenging problem as these patients require both reconstruction of the auricle and rehabilitation of hearing. * Our aim was to find the optimal position for bone-anchored hearing aids (BAHA) in patients requiring reconstruction of the auricle on the same side. * From an analysis of five such operated patients, it was found that siting a BAHA 6.5-7.0 cm from the position of the external auditory meatus is probably the correct distance to facilitate optimal auricular reconstruction. * Using these criteria, a group of another five patients with BAHA awaiting auricular reconstruction were reviewed. Of these only three (60%) have been satisfactorily sited.

Child↗

Recurrent mycobacterial breast abscesses complicating reconstruction.

We present a patient with mycobacterial infection of the breast and subsequent mastectomy. After initial reconstruction, she developed multiple recurrent abscesses around the flap. This necessitated further debridement and a second reconstruction. This case demonstrates the need to beware mycobacterial infection in patients undergoing breast reconstruction, especially after recurrent "sterile" abscesses.

Abscess↗

Mastectomy and reconstruction--an unusual solution to intractable breast pain.

Breast pain is a common complaint which usually subsides with simple reassurance or sometimes medication. This paper describes the case of a 41-year-old woman suffering from severe non-cyclical breast pain that had proved resistant to a battery of medical treatments. The pain was so disabling that it drove the patient to contemplate suicide. At the patient's request, a bilateral subcutaneous mastectomy with immediate implant reconstruction was performed, resulting in a complete resolution of the pain. Non-cyclical breast pain is less common than cyclical breast pain and tends to be more difficult to treat. This case suggests that mastectomy may be an appropriate option of last resort in the treatment of severe intractable breast pain.

Adult↗

The tuberous male breast.

Whilst tuberous female breasts are well described, the tuberous male breast is a very unusual variant of gynaecomastia. Two cases are presented, the development of the condition is considered and the surgical management is discussed.

Adolescent↗

Does low penetration of human skin by the normal mode ruby laser account for poor permanent depilatory success rates?

Studies reported to date have shown a good depilatory response from patients treated with the normal mode ruby laser (NMRL) over 12 weeks, but a low response over a time period greater than this. Previous publications have suggested that this could be accounted for by the apparently poor skin penetration of laser light and so this study attempted to assess whether this was indeed the case. Skin samples of varying thicknesses were taken from six Caucasian patients and their depths measured. Each was laid individually on an energy meter before having pulses from an NMRL compatible with clinical doses (4.75 J/cm2, 9.24 J/cm2 and 13.41 J/cm2) fired on the epidermis. Several samples had the laser fired repetitively on the surface to assess whether this caused any change in laser/skin fluence depth profiles. Repetitive firing of the NMRL on the epidermis of skin samples did not alter the energy recorded by the meter beneath. The fluence/depth profiles were constructed showing the majority of energy was lost within the first 1 mm of the skin surface (50%) which then further reduced over distance but at a much slower rate. The maximum depth of penetration was 14.8 mm (SD +/- 0.478) which appeared to be a function of wavelength and not fluence. The results suggest that laser penetration of skin should be adequate for generating enough heat at the hair bulge and bulb, potentially causing permanent damage. The implications of this study are that it is probably the presence of the correct chromophore in large enough amounts which is required for successful permanent depilation to occur.

Breast↗

Rib graft reconstruction versus osseointegrated prosthesis for microtia: a significant change in patient preference.

Until recently the options for reconstruction of the microtic ear were unsatisfactory and the ear was often left alone. With recent advances, both autologous rib reconstruction and osseointegration produce good quality results. It is our practice to offer all patients a choice of no surgery, autologous rib cartilage reconstruction or an osseointegrated prosthetic ear. This study reports on parental choice between the reconstructive options as assessed by questionnaire. Earlier patients who have had their surgery were compared with more recent patients who have chosen an option but are awaiting surgery. In the patients who have had surgery, seven (30%) chose a prosthetic ear and 16 (69.5%) chose rib cartilage reconstruction, compared to those patients that are awaiting surgery, four (11%) chose a prosthetic ear and 31 (88.6%) chose rib cartilage reconstruction. The results show a significant increase in the choice for rib cartilage reconstruction in those patients awaiting surgery. Although high quality autologous reconstruction is not widely available we feel it is important that parents are at least informed that it is an alternative to osseointegration and no surgery.

Child↗

Successful reduction in skin damage resulting from exposure to the normal-mode ruby laser in an animal model.

Normal-mode ruby laser (NMRL) irradiation of skin has now become an acceptable method of producing depilation. However, side effects, which include superficial burning and changes in skin pigmentation, still occur and, although temporary, can be distressing to the patient. This paper reports a method by which the skin can be protected (or preconditioned) from damage during NMRL treatment by pre-heating to a lower, non-damaging level prior to irradiation. Using the black-haired mouse (C57B1/10) as an animal model, an appropriate 'preconditioning' temperature was established by exposing the mouse skin to a range of temperatures, taking biopsies and staining the skin immunohistochemically for heat shock protein 70 (HSP 70) expression within the keratinocyte cells. Increased HSP 70 expression is stimulated by exposure to environmental stressors such as heat, so it was hypothesised that its increased expression conveyed increased cellular protection. The appropriate temperature (45 degrees C for 15 min) allowed for the superficial skin cells to be protected (as assessed by maximal HSP 70 staining) but undamaged (as assessed by haematoxylin and eosin staining), leaving the target hair-producing cells unprotected. Eight mice (16 flanks) were then exposed to this preconditioning temperature (eight of the flanks being growing-hair sites and eight resting-hair sites) and 5 h later exposed to a laser fluence known to cause mild skin damage and depilation (6J/cm2). This exposure was to both the preconditioned and the adjacent non-preconditioned sites. A statistically significant reduction in skin damage (P <0.001), as measured by the time taken to heal and noted both clinically and histologically, was seen in the preconditioned sites in resting-hair regions but not in growing-hair regions. Depilation, established over an 8 week period, was successful in growing-hair regions within both preconditioned and non-preconditioned sites, but complete hair regrowth had occurred in preconditioned and non-preconditioned sites within resting-hair regions by 5 weeks. The latter finding was consistent with work already reported suggesting that NMRL-assisted depilation in this animal model is not successful for hairs in the telogen phase. Successful preconditioning of mouse skin prior to laser exposure appears to reduce NMRL-induced skin side effects. In addition, the technique does not appear to adversely affect successful depilation.

Animals↗

Zimmer splintage: a simple effective treatment for keloids following ear-piercing.

An auricular keloid occurring following ear-piercing remains a difficult condition to treat. Various treatments have been described, with different reported degrees of success. Pressure therapy has been shown to be an effective treatment for auricular keloids, although the devices used have not all been universally accepted. We assessed 30 patients, between 1989 and 1999, who had been fitted with pressure devices made from Zimmer splints. There was a 50% or greater reduction in the size of each keloid when assessed at 1 year. Zimmer splints are cheap, readily available, easily moulded to fit the patient and can be decorated so that they can be worn as earrings.

Anti-Inflammatory Agents↗

A combined V-Y advancement-turnover flap for simultaneous perialar and alar reconstruction.

A modification to a standard nasolabial flap is described for the simultaneous reconstruction of confluent perialar and full thickness alar defects. The main body of the flap is advanced to cover the external surface of the perialar and alar defects. A side extension to the flap, based only on a dermal blood supply, is turned over, to line the reconstructed alar rim.

Aged↗

Hair removal using the long-pulsed ruby laser in children.

OBJECTIVE: The purpose of this study was to assess the efficacy of laser assisted hair removal in children aged 16 and under using the long pulsed ruby laser. BACKGROUND DATA: Unwanted hair in the pediatric population can be due to congenital hairy nevi and hypertrichosis. Methods of effecting hair removal include shaving, electrolysis, and laser depilation. The long-pulsed ruby laser is an established treatment modality in adults, but its use specifically in children has not been investigated. METHODS: Patients aged 16 or under undergoing treatment with the ruby laser for unwanted hair were assessed. Hair counts were determined before and after treatment and an assessment of overall satisfaction was made using a parental questionnaire. RESULTS: Treatment was regarded as successful in 25 out of 28 cases where there was a clear reduction in hair growth at the site treated with an average fall in hair count of 63% at 6 months follow up. There was no scarring or hyperpigmentation in this group and no serious complications. Total suppression of hair growth was not permanent but usually lasted between 3 and 6 months. Few problems were encountered from using the technique specifically in children, and pain was well controlled in most cases. CONCLUSIONS: We would recommend the long-pulsed ruby laser as a useful form of hair removal in children that is quick, simple and well tolerated. At present, the technique leads to hair loss that is temporary but most patients and their parents feel the treatment gives worthwhile benefits.

Adolescent↗

The temperatures reached and the damage caused to hair follicles by the normal-mode ruby laser when used for depilation.

Although it is proposed that heat is the cause of follicular damage leading to depilation, this has never been proved. This study aims to determine the mode by which depilation is effected and, if heat is the mechanism, what temperatures are reached within treated follicles and if sufficient damage is produced therein. Two excised specimens of hair-bearing skin from 5 patients undergoing facelifts were dissected to reveal the hair bulbs/shafts on the deep surface. They were placed on a jig, and one pulse from a normal-mode ruby laser (NMRL) of 15 J per square centimeter was fired on the epidermal surface. A thermal imaging camera recorded dermal temperature changes on the deep surface in real time. Specimens were then examined histologically for the site and extent of cellular damage by immunohistochemical staining for a protein marker of cell damage (p53). The NMRL targeted hair follicles specifically. The most common follicular temperature increase ranged from 5 to 10 degrees C. In specimens from 1 patient the increase was more than 30 degrees C (p < 0.001). Heat dissipation into interfollicular tissue in all specimens occurred 2 seconds after exposure. Evidence of laser-induced damage to follicle-lining cells was found only in those follicles with damaged hair shafts. The changes were found to a greater depth (to the bulb) and greater extent (beyond the bulge) in those follicles reaching higher temperatures. These findings suggest that the NMRL should produce permanent depilation. The variability between follicles and between patients explains, perhaps, the uneven outcome regarding depilation using the NMRL. Success appears to depend on peak follicular temperatures achieved during laser exposure, which may result from the follicular characteristics of the individual patient.

Body Temperature↗

A review of the ruby laser with reference to hair depilation.

There is a clinical need in the fields of reconstructive and cosmetic plastic surgery for a safe, simple, and effective method of hair depilation. Depilatory clinics have been established throughout the country, commonly using the ruby laser, to treat a cohort of the population, estimated to be between 6% and 10%, recognized as being hirsute. Clinical trials performed to date have not established a protocol that suits the previously mentioned criteria and have been, usually, small in number and short in follow-up. With the increased use that this form of laser treatment will inevitably undergo, it is the belief of the authors that the only way of ascertaining whether the treatment is safe, simple, and effective is first to establish how the ruby laser works. This review relates the knowledge that is currently available regarding the function of the ruby laser to a number of the clinical studies that have been undertaken, including three that have used other types of laser. Using this information, future areas in which research is required can be defined, ultimately to improve the clinical efficacy of ruby laser-assisted hair removal while lessening the current side effects (namely, superficial burning, and hypo- and hyperpigmentation).

Hair Follicle↗

Hair removal using the ruby laser: clinical efficacy in Fitzpatrick skin types I-V and histological changes in epidermal melanocytes.

The ruby laser is effective in removing unwanted body hair. The occurrence of cutaneous side-effects such as blistering, hypopigmentation and hyperpigmentation, however, remains problematic. These side-effects are more commonly seen in patients with dark coloured skin, which partly explains the relative scarcity of information on the efficacy of ruby laser hair removal in such patients. The mechanisms of the occurrence of these side-effects are also not known. It was the aim of this study to evaluate the efficacy of ruby laser-assisted hair removal in patients with Fitzpatrick skin type V in a retrospective clinical study and to evaluate the mechanism of post-treatment pigmentary change in a prospective clinical study. The percentage reduction in hair density in patients with skin type V was assessed after a variable period following treatment with the Chromos 694 Depilation Ruby Laser, and was compared with the results of those with skin types I-IV. To study the pigmentary change and melanocyte numbers after laser irradiation, ex-vivo scalp skin and serial patient biopsies were taken and stained with S-100, dopa oxidase and Masson-Fontana methods. Laser treatment reduced melanocyte numbers as measured by DOPA stain but not by S100. Laser treatment resulted in the clearance of pigment from the epidermis on histology. Ruby laser was shown to be effective in removing unwanted hair from patients with dark coloured skin, but with a higher incidence of cutaneous side-effects. The occurrence of hypopigmentation after laser irradiation was thought to be due to the suppression of melanogenesis in the epidermis rather than to destruction of the melanocytes.

Analysis of Variance↗