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Biomedical subjects

Bariş Cakir

Publications and source records attributed to Bariş Cakir.

15 recordsLinked to original sources
PubMed2006

"Open y" technique in vessel diameter discrepancy.

For the last 20 years, free tissue transfers have increasingly become the mainstay of plastic surgery. Size discrepancy between the vessels during tissue transfers are frequently encountered in clinical practice, and this may potentially be an important factor in the patency of anastomosis. In our clinic, we first studied a rat model and a fresh sheep cadaver to improve the diameter discrepancy in microvascular anastomosis with "open y" technique. At the end of our research, we progressed to success, and the open y technique was applied to nine patients in our clinic with a diameter discrepancy in microvascular anastomosis. After finding the bifurcation of vessels (artery, vein, or a vein graft) that are prepared for anastomosis, a distal cut of 2-3 mm was made for the anastomosis, which is considered to increase the diameter. Both legs of the resultant "y"-shaped vessel were united after inserting the microscissors from one leg and exiting from the other. Performing an end-to-end anastomosis between the vessels, we obtain an increase in the diameter. By using this method, we eliminated the diameter discrepancy in microvascular anastomosis in nine patients in our clinic. There was not any flap loss. To increase the usage of this technique, when we come across a problem of size discrepancy, it is important to use the open y technique, both to the recipient vessels, donor vessels, and to the vein grafts. Owing to its high prevalence and the ease of application, we are convinced that this is a suitable technique in appropriate cases.

Anastomosis, Surgical↗
PubMed2005

Leptin ameliorates burn-induced multiple organ damage and modulates postburn immune response in rats.

The present study was designed to determine whether exogenous leptin reduces remote organ injury in the rats with thermal burn trauma. Leptin (10 microg/kg) or saline was administered intraperitoneally after burn injury, and the rats were decapitated at either 6 or 24 h. Plasma samples of 24-h burn group were assayed for the determination of monocyte and neutrophil apoptosis. Thermal injury increased tissue-associated myeloperoxidase (MPO) activity and microscopic damage scores in the lung, liver, stomach, colon and kidney of both 6- and 24-h burn groups. In the 6-h burn group, leptin reduced microscopic damage score in the liver and kidney only, while damage scores in the 24-h burn group were reduced in all the tissues except the lung. Also, in both burn groups, leptin reduced elevated MPO activity in all tissues except the lung. The percentage of mononuclear cells was significantly reduced at the 24 h of burn injury, while the granulocyte percentage was increased. Leptin treatment, however, had no significant effect on burn-induced reversal of white blood cell ratios. On the other hand, burn-induced increase in the death of mononuclear cells and granulocytes was significantly reduced in leptin-treated rats. The results of the present study suggest that leptin may provide a therapeutic benefit in diminishing burn-induced inflammation and associated multiple organ failure.

Animals↗
PubMed2005

Effects of clopidogrel and high dose aspirin on survival of skin flaps in rats.

Clopidogrel is a new antiplatelet agent with a different mechanism of action from aspirin. It is thienopyridine derivative that is chemically related to ticlopidine, which irreversibly inhibits platelet aggregation by selectively binding to adenylate-cyclase-coupled adenosine diphosphate receptors on the platelet's surface. Aspirin is an antiplatelet agent that acetylates cyclo-oxygenase and decreases the products of arachidonic acid metabolism, including thromboxane and prostacyclin. Necrosis of a flap is still an important complication in reconstructive surgery. To investigate the effects of clopidogrel or high dose aspirin on the survival of skin flaps, 30 rats were divided into three groups of 10 animals each: a control group, a clopidogrel group, and a high-dose aspirin group. No pharmacological agents were used in the control group. Of the two treated groups, the first was given clopidogrel 50 mg/kg/day and the second aspirin 200 mg/kg/day for three days before the operation. After seven days the viable areas of each flap were evaluated and the mean (SD) percentage in the control group was 47 (6), in the clopidogrel group 63 (4), and in the aspirin group 65 (5). Although the mean area of flaps that survived in the aspirin group was slightly higher than in the clopidogrel group, the difference was not significant (p = 0.54).

Animals↗
PubMed2004

The anti-inflammatory effect of leptin on experimental colitis: involvement of endogenous glucocorticoids.

The present study was designed to compare the effect of leptin on acute colonic inflammation with that of acute stress exposure, which acts via the hypothalamic-pituitary-adrenal (HPA) axis. Sprague-Dawley rats of both sexes were administered intrarectally with acetic acid. Either leptin (10 microg/kg; i.p.) or saline was injected immediately before and 6 h after the induction of colitis. A group of rats was exposed to water avoidance stress (WAS) for 30 min at the 6th h of colitis induction. RU-486 (2 mg/kg; i.p.), a glucocorticoid receptor antagonist, was injected intraperitoneally, at 12 and 1 h before the initial leptin injection, and at 1 h before the second leptin injection or exposure to WAS. Rats were decapitated at 24 h and the distal 8 cm of the colon were removed for macroscopic and microscopic scoring, determination of tissue wet weight index (WI) and tissue myeloperoxidase activity (MPO). Acetic acid-induced colitis significantly increased macroscopic and microscopic damage scores, WI and MPO, compared to control group. Exposure to acute WAS or treatment with leptin reduced the elevations in damage scores, WI and MPO induced by colitis, but no additive inhibitory effect was observed when WAS and leptin were applied together. RU-486 treatment reversed the inhibitory effects of leptin or WAS on colonic inflammation. Our results demonstrate that exogenous leptin mimics the effects of HPA axis activation on colitis-induced inflammatory process. The results also suggest that the anti-inflammatory effect of leptin involves a tissue neutrophil-dependent mechanism and is dependent on the release of glucocorticoids.

Acetic Acid↗
PubMed2004

Can indications for lower limb replantation and revascularization be expanded with simultaneous free-flap transfer for limb salvage?

High-energy trauma from road accidents and work-related injuries is the most common cause of lower-limb traumatic amputations. Many of these cases require extensive debridement and substantial bone shortening for primary closure because of crushing and/or avulsion of the involved parts. Since 1998, the authors have replanted or revascularized five lower limbs in five patients. Free tissue transfers have been used to cover soft-tissue defects during replantation and revascularization in all patients. The numbers and kinds of free flaps include one latissimus dorsi muscle, two transverse rectus abdominis musculocutaneous (TRAM), and two anterolateral thigh fasciocutaneous flaps. Survival of the replanted and revascularized limbs and transferred flaps was obtained in four patients. Below-knee amputation was performed because of flap necrosis and extensive infection in one patient. Simultaneous free-tissue transfers may be used simultaneously with lower limb replantation or revascularization to obtain functional extremities in appropriately selected patients. The indications for lower limb salvage may be enhanced and successful results may be obtained in one stage, with low complication rates and shorter hospital stays. The authors report their experience with simultaneous free tissue transfers and lower limb replantation or revascularization.

Adolescent↗
PubMed2004

Increasing vessel diameter with the open Y technique for diameter discrepancy.

Free tissue transfers have increasingly become the mainstay of plastic surgery for the last two decades. Size discrepancy between the vessels in microsurgery is frequently encountered in clinical practice and may potentially be an important factor in the patency of the anastomosis. A rat model has been devised to improve the diameter discrepancy in microvascular anastomosis. Twenty Wistar rats have been used for this purpose. The external jugular vein was cut 1 mm distally from the bifurcation of the anterior and posterior facial veins. Both legs of the resultant Y-shaped vessel were united after inserting microscissors from one leg and exiting from the other. Performing an end-to-end anastomosis between the vein, which acquired an increased diameter as a result of this procedure, and the carotid artery prepared in the neck, helped to create an arteriovenous shunt. Patency was assessed in the operated rats 2 weeks later. In order to achieve a better understanding of the advantages of this technique, another study was carried out. In this subsequent study, specimens were collected from fresh sheep cadavers, including the brachiocephalic trunk, right common carotid, and right subclavian arteries. Different specimens were compared from each of the vessels and also from each of the subclavian and carotid arteries after they were joined together with the open Y technique and increased diameters of the vessels are obtained. As a result, the authors demonstrated that size discrepancy between the vessels was decreased, patency with a percentage of 94.1 was obtained, and when specimens from the fresh cadavers were evaluated, a reasonable gain was achieved. (p < 0.0001).

Anastomosis, Surgical↗
PubMed2004

[Successful results with the use of a new reconstruction material for soft tissue defects of the lower extremity: neurocutaneous flaps].

BACKGROUND: We evaluated the use of distally based neurocutaneous flaps in the reconstruction of soft tissue defects in the lower extremity caused by trauma or other reasons. METHODS: Sixty-six patients (49 males, 17 females; mean age 42 years; range 16 to 75 years) underwent reconstruction of lower extremity soft tissue defects with the use of neurocutaneous flaps. The defects were in the external (n=11) and internal malleolus (n=10), Achilles tendon (n=6), heel (n=11), foot (n=7), distal (n=9) and middle (n=7) third of the anterior tibia, the mid-plantar region (n=3), and the popliteal region (n=2). Sural and saphenous neurocutaneous flaps were used in 34 and 32 patients, respectively. The mean flap area was 135 square centimetres (range 54 to 286). The mean follow-up period was 32 months (range 11 to 58 months). RESULTS: Of sixty-six patients treated with neurocutaneous flaps, complete survival was achieved in 57 flaps (86.4%). Partial necrosis was encountered in six patients (9%). Total flap loss occurred in three patients (4.6%) who had diabetes, hypertension, and electrical burns, respectively. The most common complication during the postoperative period was venous congestion seen in 14 patients (21%), the majority of whom had diabetes (n=5), hypertension (n=3), and electrical burns (n=3), predisposing them to microcirculation disorders. This complication was successfully managed by leech therapy in 78.6%. CONCLUSION: Neurocutaneous flaps offer maximum reconstruction capacity with minimum donor site morbidity, making them a successful alternative in the treatment of soft tissue defects of the lower extremity in recent years.

Adolescent↗
PubMed2003

Anti-inflammatory effects of leptin and cholecystokinin on acetic acid-induced colitis in rats: role of capsaicin-sensitive vagal afferent fibers.

Leptin and cholecystokinin (CCK) have a synergistic interaction in the suppression of food intake, and afford similar gastroprotective activity. The present study was designed to investigate the putative protective effects of CCK and leptin on acute colonic inflammation. Leptin or CCK-8s was injected to rats intraperitoneally immediately before and 6 h after the induction of colitis with acetic acid. CCK-A receptor antagonist (L-364,718) or CCK-B receptor antagonist (L-365,260) was injected intraperitoneally 15 min before leptin or CCK treatments. In a group of rats, vagal afferent fibers were denervated by topical application of capsaicin on the cervical vagi. Rats were decapitated at 24 h, and the distal 8 cm of the colon were removed for macroscopic scoring, determination of tissue wet weight index (WWI), histologic assessment and tissue myeloperoxidase (MPO) activity. All inflammation parameters were increased by acetic acid-induced colitis compared to control group. Leptin or CCK-8s treatment reduced these parameters in a similar manner, while co-administration of leptin and CCK was found to be more effective in reducing the macroscopic score and WWI. CCK-8s-induced reduction in the score and WWI was prevented by CCK-A, but not by CCK-B receptor antagonist, whereas neither antagonist altered the inhibitory effect of leptin on colitis-induced injury. On the other hand, perivagal capsaicin prevented the protective effects of both CCK-8s and leptin on colitis. Our results indicate that leptin and CCK have anti-inflammatory effects on acetic acid-induced colitis in rats, which appear to be mediated by capsaicin-sensitive vagal afferent fibers involving the reduction in colonic neutrophil infiltration.

Acetic Acid↗
PubMed2003

Giant fibrosarcoma arising in dermatofibrosarcoma protuberans on the scalp during pregnancy.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a low-grade malignant soft tissue tumor of subcutaneous tissues that has a propensity for local recurrence; however, it seldom metastasizes. Most lesions occur over the trunk or proximal extremities, and there is slight male preponderance. DFSP is rare on the head and neck. Less than 5% tumors are located on the scalp. OBJECTIVE: To describe a case of giant fibrosarcoma arising in DFSP on the scalp during pregnancy. METHOD: In our patient, the tumor was on scalp and measured 15 x 11 x 7 cm. The recurrent tumor that developed in the same region was measured 33 x 30 x 15 cm. Histopathologic examination of this mass revealed fibrosarcoma. The mass was excised from the subperiosteal plane with a 3-cm free margin. Because of the high possibility of recurrence, the defect site was reconstructed with a split-thickness skin graft. RESULTS: After 1 year of follow-up, no recurrence or metastasis was detected. CONCLUSION: We present a unique case in which the person has a giant fibrosarcoma on her scalp arising from DFSP with fibrosarcomatous change during pregnancy.

Adult↗
PubMed2003

Long-term fate of vascularized iliac bone flap as a source for phallic rigidity.

One of the surgical goals of phalloplasty is to obtain sufficient rigidity for sexual penetration. This is also important for patients with erectile dysfunction. Different kinds of techniques have described phalloplasty and obtaining rigidity in patients with erectile dysfunction, but there is no good substitute for the erectile tissue of the penis. The authors used an iliac osteocutaneous flap for phalloplasty and a vascularized bone flap for imitating penile erection. Five patients who had undergone either phalloplasty or correction of erectile dysfunction are presented. Long-term results are promising in adults and the authors advocate using vascularized iliac bone for sufficient rigidity of a (neo)phallus. However, the results are moderate for children who have undergone previous phalloplasty.

Adult↗
PubMed2003

[The management of size discrepancies in microvascular anastomoses].

OBJECTIVES: Microvascular anastomosis is the main component of flap transfer and replantation surgery. The aim of this study was to evaluate size discrepancies encountered during microvascular surgery, techniques to handle the problems, and the results of anastomoses performed. METHODS: We evaluated 99 microsurgery operations (103 artery, 125 vein anastomoses) performed in 96 patients with respect to size discrepancy. These operations included free flap transfer (n=67), replantation (n=23), revascularization (n=6), and toe-to-hand transplantation (n=3). Size discrepancy was defined as the inequality of vessel diameters at a ratio of 1:1.5 or greater. RESULTS: Size discrepancy was found in 32.5% (n=74) of 228 anastomoses, the most frequent being in vein anastomoses performed during free flap transfers. Simple discrepancies were dealt with by dilatation with the use of a jeweller's forceps in 14 anastomoses. In nine discrepancies exceeding 1:1.5, the oblique cut, fish mouth cut, and sleeve techniques were employed in four, three, and two anastomoses, respectively. End-to-side anastomosis was used in six patients in whom free flap transfer was carried out for extremity defects. The remaining 45 anastomoses were performed using a modification of the Xiu and Song's method. Venous grafts were used because of tension of the anastomosis and insufficient vessel lengths in three, eight, and three patients who underwent replantation, free flap transfer, and revascularization, respectively. CONCLUSION: An appreciation of various techniques is essential to avoid discrepancy-related problems both during and following microvascular surgery.

Anastomosis, Surgical↗
PubMed2002

Protective role of cyclooxygenase (COX) inhibitors in burn-induced intestinal and liver damage.

The aim of this study was to investigate the role of cyclooxygenase (COX) inhibition in intestinal motility and in the extent of tissue injury of the small intestine and liver with the use of various COX inhibitors. Wistar albino rats were exposed to 90 degrees C water bath for 10s. The intestinal transit index decreased compared to control group and treatment with nimesulide (NIM; 10mg/kg, subcutaneously) or piroxicam (Pir; 5mg/kg, orogastrically) reversed this effect significantly. The intestinal and liver glutathione levels showed a significant decrease in the burn group compared to sham (P<0.001 and P<0.05, respectively). Decrease in intestinal glutathione level was reversed by NIM or Pir treatment (P<0.01 and P<0.01, respectively), whereas all drugs tested were effective in reversing low liver glutathione level. The MPO activity in intestinal segments were significantly high in burned animals compared to sham. All test drugs reversed this effect but ketorolac (Ket; 3mg/kg, orogastrically) was the most effective one. The liver samples characterized by sinusoidal dilatation and pericentral atrophy in burn group were protected by treatment with Ket or Pir (P<0.05). Plasma ALT and AST activities were markedly high in this burn group compared to sham (P<0.0001 and P<0.001, respectively). None of the agents reversed these high enzyme activities. These data suggest that not only COX-2 but also COX-1 inhibition is required for protection against inflammatory changes in liver and small intestine following burn injury.

Animals↗
PubMed2002

Localization and removal of ferromagnetic foreign bodies by magnet.

Foreign bodies should be removed from wounds during the primary wound management stage whenever possible. Metallic fragments can be identified and localized by conventional radiography, computed tomography, sonography, x-ray image intensifier, or electromagnetic metal detector. Locating metallic objects may still cause problems for the surgeon during the removal procedure. Detection and removal of superficial ferromagnetic fragments (iron, nickel, and cobalt) by a magnet is possible. In the literature the authors found no report about using the magnet for this purpose. Having conferred with the manufacturer KANAT (Istanbul, Turkey), the authors used a magnet made of neodymium. The power of the magnet was 12,000 gauss. It was cylindrical and 1.3 x 0.8 cm in diameter. This method was used in 6 patients successfully for localization and removal of ferromagnetic foreign bodies. Use of a magnet is an easy and cost-effective method that does not require education and specific staff.

Ferric Compounds↗
PubMedDate not supplied

Ice application to minimize pain in the split-thickness skin graft donor site.

Reconstruction of tissue defects with skin grafts is one of the most used processes in soft tissue defects. While any part of the body can be used as a donor site of split-thickness skin grafts, the posterolateral thigh is the most used one. Pain in the graft donor site may be the primary concern of patients in the postoperative period. Various kinds of donor site dressings and procedures have been described for this purpose. The main goal of this practice is the fast recovery of the donor site. Nevertheless, avoiding infection, decreasing the pain in the donor site, and minimizing the cost should be considered. To minimize pain in the graft donor site, ice pack application, used for its local anesthetic effect, was utilized for patients postoperatively in our clinic. Thirty-six patients were included in this study between June 2001 and May 2002. Patients were divided into two groups, with 18 patients in-group I, to whom ice was applied, and 18 patients in group II, which was specified as the control group. The patients were evaluated according to the pain in the graft donor site. The visual analog scale (VAS) was used to evaluate the pain of the patients. The data were statistically evaluated with the Mann-Whitney U test procedure. In addition to this, infections, recovery periods, and cost benefit effects were also determined. The mean pain scores in the graft donor site were found to be quite low in patients in the group with ice application (p < 0.05). No significant difference was determined between the two groups when their pain scales were compared on the fourth and the fifth days (p > 0.05). Ice can be safely used in patients for whom donor site pain is the primary concern, with advantages such as ease of application, low cost (almost free), and a significant decrease in pain in the donor site.

Denervation↗