PubMed Health⌕ Search

Biomedical subjects

Yücel Erk

Publications and source records attributed to Yücel Erk.

8 recordsLinked to original sources
PubMed2005

Blood loss and transfusion rates during repair of craniofacial deformities.

Surgical procedures for correction of craniofacial deformities resulted in unavoidable and extensive blood loss in small children and infants. Almost all of the patients undergoing these procedures will undergo a blood transfusion either during or immediately after the operation. A retrospective review of 30 patients who underwent craniofacial surgery was performed in this study to determine the magnitude of transfusion required for craniofacial surgery, document transfusion morbidity, and identify variables associated with the transfusion. The mean estimated blood loss was 566.8 mL, the mean intraoperative transfusion was 394.8 mL, the mean postoperative transfusion was 103.2 mL, and the mean total transfusion was 505 mL. The mean operative time was 450 minutes, the mean preoperative hemoglobin and the mean postoperative hemoglobin before hospital discharge were 11.6 g/dL and 10.3 g/dL, respectively. Craniofacial surgical procedures involve extensive scalp dissection and calvarial and facial bone osteotomies in patients with a low total blood volume. Every medical and surgical strategy for minimizing the need for blood transfusion should be considered.

Blood Loss, Surgical↗
PubMed2004

Isolated supraorbital rim fracture displaced out of scalp: a case report.

Isolated fractures of the supraorbital rim are rarely seen. In this report, an isolated supraorbital rim fracture is presented in which the segment of the rim was completely removed from its location onto the frontal bone in a traffic accident. It was thought to be a foreign body and was delivered outside the scalp in the emergency service. It was replaced 24 hours after the trauma, and the patient healed without any problem.

Child, Preschool↗
PubMed2004

Solvent-dehydrated calvarial allografts in craniofacial surgery.

Craniofacial surgery almost always requires the use of bone grafting. Although autografts are the standard procedure for bone grafting, it is sometimes not possible to harvest bone, and autografts have particular risks. The use of allograft bone provides a reasonable alternative to meet the need for graft material. Solvent dehydration is a multistage procedure in which human cadaveric bone is processed by osmotic exchange baths and gamma sterilization. This processing avoids the risk of infection transmission, decreases antigenicity, and does not weaken the mechanical properties of the bone. Solvent-dehydrated, gamma-irradiated human calvarial bone allografts were used for reconstruction of craniofacial deformities in 24 patients between 1988 and 2002. Resorption of the allografts and results of the surgical intervention were evaluated with plain radiographs and three-dimensional computed tomography 12 months after surgery, in 21 patients. Serologic tests for human immunodeficiency virus-1 antibody, hepatitis B surface antigen, and hepatitis C antigen were also performed. Biopsy specimens were taken from the allografts. Average follow-up in this group was 30 months (range, 8 to 60 months), and results of serologic tests were negative in all patients. Seventy-one percent of the patients (15 of 21) showed no resorption, with partial and complete allograft fusion. One patient had nearly total graft loss and the remaining five patients had 10 to 25 percent graft resorption. Rigid fixation of the allograft, contact with the dura and periosteum, and prevention of dead spaces around the allograft are the most important factors in achieving a satisfactory result. In solvent-dehydrated bone allografts, sterilization and antigenic tissue cleaning are achieved after several steps with a minimal dose of radiation. The result is a nonantigenic, sterile mechanical scaffold that can tolerate external forces. Although autografts are the standard in craniofacial surgery, solvent-dehydrated calvarial bone allografts produced successful results in selected cases.

Adolescent↗
PubMed2002

Tissue response to N-butyl-2-cyanoacrylate after percutaneous injection into cutaneous vascular lesions.

Despite the fact that cyanoacrylates, a group of rapidly polymerizing adhesives, are used widely in general surgery, neuroradiology, otolaryngology, and plastic surgery, scientific data on histopathological changes resulting from the deposition of -butyl-2-cyanoacrylate (NBCA), a new-generation cyanoacrylate derivative, in human tissues is based largely on experimental observations in animals and sporadic postmortem studies in humans. The authors report the consecutive pathological findings of a patient who underwent surgery for facial hemangioma after percutaneous injection of NBCA for devascularization of a lesion, and underwent additional surgery 1 and 6 months after the initial operation for the removal of the residual NBCA cast from the injection site. Acute inflammatory findings after injection of NBCA and the development of a chronic granulomatous foreign body reaction support the histological findings of experimental animal studies and postmortem examinations on humans. Additionally, their findings support the proposed hypothetical sequence of events for the recanalization of cyanoacrylate-embolized vascular structures.

Arteriovenous Malformations↗
PubMed2002

Reinnervation of denervated muscle in a split-nerve transfer model.

This study was performed to quantify the reinnervation of denervated muscle in a split-nerve transfer model and to determine any possible downgrading effects on the donor nerve and its end organ. Fifty-four adult Wistar rats weighing 200 to 250 g were used. The experimental design consisted of two groups. The motor nerve branch to the anterior tibial muscle and gastrocnemius muscle of the right hind limb were dissected in all rats. In the experimental group (N = 36), the motor nerve branch of the tibial nerve to the gastrocnemius muscle was exposed, cut, and ligated. The motor nerve branch to the anterior tibial muscle was split and transected longitudinally, and the medial half was routed posteriorly. End-to-end neural anastomosis was performed between this medial half of the split nerve and the distal stump of the gastrocnemius nerve. In the control group (N = 18), while the same surgical preparation was performed, the motor nerve branch to the anterior tibial muscle and gastrocnemius nerve were exposed and transected, and the nerve endings were ligated, but neural anastomosis was not performed between these nerves. The left hind limb of all rats served as a normal comparison side without any surgical intervention. Both of the groups were divided into three subgroups (12 rats each for the experimental groups and 6 rats each for the control group) to evaluate the results after periods of 1, 3, and 6 months. Electromyography, light microscopic and morphometric examination, and muscle weight measurements were used to document the results. Although stimulation of the peroneal and tibial nerves did not produce any compound muscle action potential (CMAP) recordings from either the anterior tibial or the gastrocnemius muscle in the control group, the normalized CMAP areas of the tibial nerve were (mean +/- standard deviation) 16.2 +/- 30.8% in the 1-month group, 63.4 +/- 34.7% in the 3-month group, and 72.4 +/- 16.3% in the 6-month group. For the peroneal nerve, the normalized CMAP areas were 17.0 +/- 32.2%, 53.4 +/- 29.4%, and 54.4 +/- 14.5% for the 1-, 3-, and 6-month groups in the experimental groups respectively. A high number of regenerating myelinated nerve fibers was identified in the distal part of the coapted motor nerve branch to the gastrocnemius muscle. The average number of myelinated fibers in the lateral half of the split nerve in the experimental group was 15,108 fibers per square millimeter, 14,167 fibers per square millimeter, and 19,830 fibers per square millimeter at months 1, 3, and 6 respectively. The average number of fibers proximal to the nerve anastomotic site was 15,423 fibers per square millimeter, 19,200 fibers per square millimeter, and 20,774 fibers per square millimeter. Distal to the nerve anastomotic site, the number of myelinated fibers was 17,941 fibers per square millimeter, 18,885 fibers per square millimeter, and 18,895 fibers per square millimeter at 1, 3, and 6 months respectively. There were no myelinated fibers in the control group sections. There were significant differences in muscle weight between the experimental and control groups at the end of month 6. The difference between the experimental side and the untouched normal healthy side was not significant in the weight measurements of both muscles. The results show acceptable reinnervation by split-nerve transfer with minimal functional impairment of the donor muscle. This study confirms that split-nerve transfer is a reliable method of reconstruction for paralyzed muscle with minimal donor area morbidity.

Animals↗
PubMedDate not supplied

A new experimental hypertrophic scar model in guinea pigs.

Many aspects of the biology and effective therapy of proliferative scars remain undefined, in part due to a lack of an accurate, practical, reproducible, and economical animal model for systematically studying hypertrophic scars. This study was designed to investigate whether hypertrophic scar formation could be induced in guinea pigs by removal of the panniculus carnosus alone, and by a combination of the removal of the panniculus carnosus with application of coal tar afterwards. Whole thickness skin excision or deep partial thickness injury was used to create the lesions on intact skin. Different anatomic locations were tested in different groups. Scars thus developed were examined morphologically by light microscopy and electron microscopy (TEM and SEM) and biochemically by measuring the activity of glucose-6-phosphate dehydrogenase (G6PD) to check whether these scars had morphological and biochemical properties specific to hypertrophic scars. The albino guinea pigs used in this study were divided into three groups. Removal of the panniculus carnosus was performed from the ventral aspect of the torso in animals in groups I and II. On the skin overlying the area of panniculectomy, circular skin excision was performed in group I, and deep partial thickness burn injury was inflicted in group II, to see whether wounds would heal with hypertrophic scars. In group III, dorsal aspect of the torso were used and wounds were produced by circular skin excisions followed by panniculectomy on both sides but coal tar was applied to only one side. Tissue samples were taken from the scars that were hypertrophic in appearance, and from normal scars and normal skin for comparison. Light and electron microscopic examinations and G6PD activity measurements were performed on these samples. While hypertrophic scar development was not seen in group I and group II, scars with morphological and biochemical properties specific to hypertrophic scars developed in one third of animals in group III after healing of the wounds treated with coal tar. In conclusion, it is shown that it is possible to develop experimental hypertrophic scars in guinea pigs with morphological and biochemical properties similar to those of human proliferative scars. Therefore this model is a new, practical, and economical experimental animal model to study proliferative scars, although improvements are needed to increase yield.

Animals↗