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Biomedical subjects

R Yavuzer

Publications and source records attributed to R Yavuzer.

At least 37 records · Page 2Linked to original sources
PubMed2000

Hydroxyapatite cement: an alternative for craniofacial skeletal contour refinements.

Hydroxyapatite cement is a calcium phosphate preparation composed of tetracalcium phosphate and dicalcium phosphate anhydrous powders. When mixed with water it isothermically forms a paste which can easily be shaped intraoperatively. This mixture sets in approximately 15-20 min and converts into water insoluble, nonceramic, microporous hydroxyapatite in 4 h. This biomaterial was used to correct either congenital or traumatic craniofacial contour irregularities or deficiencies in 20 patients. On follow-up there was only one patient who required repeat surgery for further correction, there were no other complications. The good cosmetic results, the ease of operation, the pliability of the cement paste allowing precise moulding during application, the short operation time and the avoidance of a donor site makes hydroxyapatite cement an attractive material for treating craniofacial contour defects. Careful long term follow-up is necessary to establish its safety and reliability.

Adolescent↗
PubMed2000

Use of the turnover epineurial sheath tube for repair of peripheral nerve gaps.

Autologous nerve grafting is the conventional technique for bridging nerve gaps, despite its various disadvantages. In this study, the authors investigated the effects of the turnover epineurial sheath tube (TEST) as an alternative to nerve grafting for the repair of nerve gaps, using a rat sciatic nerve model in four groups: Group 1 (n = 5): sham control; Group 2 (n = 10): segmental nerve resection + no repair; Group 3 (n = 10): segmental nerve resection + nerve grafting; Group 4 (n = 15): segmental nerve resection + TEST. Functional recovery was evaluated by walking-track analysis. The sciatic nerves and gastrocnemius muscles were harvested for histologic and quantitative histomorphometric evaluation at 12 weeks. Sciatic functional indices and histomorphometric analyses revealed statistically significant differences between the sham control and the three experimental groups (p < 0.001). The difference between the TEST group and the nerve graft group was not significant; however functional recovery was significantly improved in these two groups, compared to the non-repaired group (p < 0.05). The authors suggest that the TEST provides a suitable conduit between two stumps, eliminates donor-site morbidity, reduces the number of suture sites, fibrosis, and operating time, and might be an alternative to nerve grafting for nerve gap repair.

Animals↗
PubMed2000

Surgical treatment of urethral fistulas following hypospadias repair.

Development of urethral fistulas is one of the most common late complications of hypospadias surgery. A total of 161 male patients who had 186 urethrocutaneous fistulas were first classified according to the fistula classification of Horton and colleagues and then treated with three types of procedures: simple closure, local rotation flaps, or tube graft reconstruction. With initial surgical intervention, 156 of 186 fistulas were treated successfully. The remaining 30 fistulas (16.1%) recurred during the follow-up period. In the recurrent cases, immediate closure was not preferred, and an average of 6 months was waited before considering any additional surgical attempt. Distal cases had a higher failure rate, and the simple closure technique failed to show a success rate as high as local flap or tube graft repair. The high recurrence of distal cases was attributed mainly to the lack of adequate soft tissue adjacent to the fistula, which is vital for safe closure. In addition, the traction effect of erection on the skin and urethra, which is more prominent distally than proximally, is also believed to play an additive role. To increase success, the selection of appropriate treatment modality and customization of techniques for each patient cannot be overemphasized. However, the authors conclude that careful presurgical assessment of the patient, a 6-month delay before any secondary surgical attempt, inversion of the urethral mucosa, avoidance of any overlapping suture lines, urinary diversion proximal to the repair site for 5 to 11 days, and usage of thin, absorbable suture materials are the main criteria that should be met for a satisfactory hypospadias fistula repair.

Adolescent↗
PubMed2000

Prevention of meatal stenosis with W-flap glanuloplasty in hypospadias surgery: a long-term follow-up.

Meatal stenosis is a complication that can occur after hypospadias surgery. Although there are many different surgical techniques that can solve this problem, once it has occurred, meatal stenosis can be difficult to treat. To decrease meatal stenosis risk and to achieve an anatomically placed, aesthetically pleasing meatal opening, a new W flap was designed for glanuloplasty. The authors describe the technique in detail along with long-term results. A total of 356 hypospadias cases were operated using various urethroplasty methods. Independent from the preferred urethroplasty method, the W-flap was used for glanuloplasty in all patients. Patients were followed for 1 to 10 years. Meatal stenosis incidence was 0.8%, and good cosmetic results with a natural-looking, anatomically placed meatus and a well-directed urinary stream during urination were achieved. W-flap glanuloplasty, an addition to reconstructive surgeons' armamentarium, is applicable to most patients. It places the meatus in its appropriate anatomic location, increases the meatal diameter by insetting two flaps, avoids a circular anastomosis, reduces the risk of late contraction, helps to achieve good aesthetic results with good urinary stream, eliminates the need for stents, and reduces meatal stenosis risk overall. It is a good glanuloplasty alternative that can be applied with most hypospadias repair techniques.

Adolescent↗
PubMed2000

Spontaneous bone healing in the rabbit.

Cranioplasty is the most common method for correcting cranial defects. A number of innovations have been made to optimize bone repair. Before their use in humans, extensive animal trials must be performed to establish efficacy. However, the literature provides only scant and inconsistent data regarding animal controls. The purpose of this study, therefore, was to determine the critical size cranial defect in the rabbit model. Cranial defects ranging from 0.5 to 1.5 cm were created in 18 New Zealand White rabbits. The rabbits were then killed at 9 and 18 weeks and the defects examined using CT imaging and histologic analysis to determine bone healing. It was determined that cranial defects greater than 1.5 cm failed to heal spontaneously. Thus, the critical size cranial defect in the rabbit model is 1.5 cm.

Animals↗
PubMed2000

Three-layer closure of an oroantral-cutaneous defect.

Reconstruction of oroantral defects, which are usually caused by tumor resection, is challenging. These defects become an even more difficult problem when they comprise multiple layers including oral mucosa, subcutaneous tissue, muscle and skin. This paper describes such a case in which a three-layer closure using a palatal flap, a buccal fat pad flap and a local skin flap was successfully performed.

Adenocarcinoma↗
PubMed1999

Ileal and colonic contractions by endothelin-1 in experimentally induced paralytic ileus in rats.

The aim of the present study was to investigate the effect of endothelin-1 on the isolated distal ileum and proximal colon in an experimentally induced ileus in rats. Ileal and colonic contractions by endothelin-1, acetylcholine alone and with endothelin-1 were recorded both in normal and experimentally induced paralytic ileus in rats. In the control group, all the responses to acetylcholine were found to be potentiated significantly when used together with endothelin-1 but in paralytic ileus group, no detectable change was observed in the responses of the amine after administration of acetylcholine together with endothelin-1. This study indicates that endothelin-1 might have an effect on gastrointestinal motility and postoperative paralytic ileus.

Acetylcholine↗
PubMed1999

A case of atypical McCune-Albright syndrome requiring optic nerve decompression.

McCune-Albright syndrome (MAS) is a disease of noninheritable, genetic origin defined by the triad of café-au-lait pigmentation of the skin, precocious puberty, and polyostotic fibrous dysplasia. This syndrome, which affects young girls primarily, has also been reported with other endocrinopathies, and rarely with acromegaly and hyperprolactinemia. The fibrous dysplasia in MAS is of the polyostotic type and, apart from the characteristic sites such as the proximal aspects of the femur and the pelvis, the craniofacial region is frequently involved. A male patient with MAS presented with juvenile gigantism, precocious puberty, pituitary adenoma-secreting growth hormone and prolactin, hypothalamic pituitary gonadal and thyroid dysfunction, and polyostotic fibrous dysplasia causing optic nerve compression. Visual deterioration and its surgical management are presented.

Adolescent↗
PubMed1999

Surgical management of penoscrotal lymphangioma circumscriptum.

Lymphangioma circumscriptum of the penis and scrotum is an unusual entity that may be indistinguishable from genital warts. After confirmation of the diagnosis, a treatment plan consisting of wide excision should be outlined. To lower the chance of recurrence, not only the affected skin but all the subjacent subcutaneous tissue, including the deeper components of the lymphatic malformation just above the deep fascia, should be removed.

Child↗