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OBJECTIVES: In the present study, we aimed to deterimine the dose-related effects of ticagrelor, the first reversible inhibitor of the P2Y(12) receptor, found in smooth muscle cells as well as platelets, during neointimal hyperplasia in a rabbit carotid anastomosis model. METHODS: This study was an experimental, prospective, randomized controlled study including 20 New Zealand white female rabbits (6-months old; weighing 2300 +/- 300 g). Under general anaesthesia, the rabbits underwent transection of the right carotid artery and subsequent anastomosis of both ends. The study animals were divided into the following 4 groups: T1 (ticagrelor 5 mg/kg, orally, daily), T2 (ticagrelor 10 mg/kg, orally, daily), T3 (ticagrelor 20 mg/kg, orally, daily) and control (no ticagrelor treatment). The single oral doses were administered in phosphate-buffered saline. The control group received sterile phosphate-buffered saline (2 ml/kg/day, orally) for 3 weeks postoperatively. At the end of the study, the animals were killed, and the anastomosed segment of the right carotid artery and part of the left carotid artery were excised from each animal. Antibodies against transforming growth factor-beta were used in staining of arterial sections, which was followed by histomorphological and immunohistochemical studies. RESULTS: The median intimal thickness (2.0 +/- 0.14 m left vs 73.4 +/- 35.8 m anastomosed right arteries; P

In this study, the effects of periosteal autograft and human amniotic membrane on tendon healing were compared. Forty-two New Zealand rabbits were divided into three groups. Flexor digitorum fibularis tendons were cut and repaired with a modified Kessler technique and circumferential sutures in all groups. Tendon repair alone was carried out in group 1, tendon repair and application of human amniotic membrane was done in group 2 and tendon repair and application of periosteal autograft was done in group 3. Biomechanical and histopathological examinations were done 2 and 6 weeks postoperatively. Biomechanical examination showed that group 3 was the strongest at weeks 2 and 6. Adhesion, inflammation and new bone formation showed no difference between groups at week 2. However, adhesion formation was found to be less in groups 2 and 3 than group 1 at week 6. The application of periosteal autograft might be useful in repair of tendon injuries.

Background. During off-pump coronary bypass grafting, local vascular control of the target vessel and a bloodless field are crucial. The aim of this study is to asses the histopathological outcomes of intracoronary shunts and bulldog clamping on the beating heart in a canine model. Methods. Twelve healthy adult mongrel dogs weighing between 15 to 25 kg were included in the study. Following left thoracotomy, proximal left anterior descending artery segment 1 cm to distal of diagonal branch was marked. Arteriotomy at this site was performed and a shunt was inserted for 10 min in the shunt group. The bulldog clamp was applied 3 cm distal to the mark for 10 min after heparinization in the bulldog group. Thirty days after the procedure, the specimens of left anterior descending artery from both regions were collected and were examined. Vascular damage, presence of intimal hyperplasia, and denudation were noted. Results. Only intimal denudation was found significantly higher in the shunt group (P < 0.05). In this group, only one case had grade 0 endothelial damage. In the bulldog group, all cases had endothelial damage of various grades. Conclusion. The proven advantages of temporary intracoronary shunts are well-known, e.g., preserving the ventricular functions. Despite these advantages, our study revealed an ultimate bad result for an off-pump coronary by pass patient: intimal denudation. We conclude that further studies with a larger number of subjects are needed to decide whether routine shunt insertion into coronary arteries during off-pump coronary bypass surgery is appropriate or not.

The aim of this study was to compare the clinical and histopathological effects of tripeptide copper complex (TCC) and two different doses of laser application (helium-neon laser, 1 and 3 J cm(-2)) on wound healing with untreated control wounds. Experimental wounds were created on a total of 24 New Zealand white rabbits and topical TCC or laser was applied for 28 days. The wounds were observed daily, and planimetry was performed on days 7, 14, 21 and 28 to measure the unhealed wound area and percentage of total wound healing. Biopsies were taken weekly to evaluate the inflammatory response and the level of neovascularization. The median time for the first observable granulation tissue was shorter (P < 0.05) in the low and high dose laser groups than in the control group (3 and 2.66 vs. 4.5 days), but was not different between the TCC and control groups (4.16 vs. 4.5 days). Filling of the open wound to skin level with granulation tissue was faster (P < 0.05) in the TCC and high dose laser groups than in the control group (14 and 16 vs. 25 days), but was not different between the low dose laser and control groups (23 vs. 25 days). The average time for healing was shorter (P < 0.05) in the TCC and high dose laser groups (29.8 and 30.2 vs. 34.6 days), but was not different between the low dose laser and control groups (33.8 vs. 34.6 days). Histopathologically, wound healing was characterized by a decrease in the neutrophil counts and an increase in neovascularization. The TCC and high dose laser groups had greater neutrophil and vessel counts than in the control group, suggesting a more beneficial effect for wound healing.