Ahmet Demir

ONEP Aesthetic-Plastic Surgery Science Institute, İstanbul, Istanbul, Turkey

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Publications (35)71.7 Total impact

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    ABSTRACT: Primary nerve repair is the gold standard in nerve reconstruction. When primary repair is not possible for injured nerves, conduit-assisted repair methods are frequently used. As conduits, autologous vein segments or allogenic biodegradable products can be used. However, their effectiveness when used in a nerve defect where a size discrepancy exists has not been compared. In this study, either a vein graft or a synthetic collagen conduit was used to bridge 10-mm defects between size-discrepant tibial and peroneal nerves in a rat model. After 90 days, nerve regeneration was evaluated using electrophysiological and histological methods. It can be concluded based on the results of this study that bridging a 10-mm nerve gap with synthetic collagen conduits and autologous vein grafts yielded similar results in small-to-large nerve coaptations, with the vein graft being slightly more effective.
    Journal of Reconstructive Microsurgery 03/2014; · 1.00 Impact Factor
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    ABSTRACT: Vessel grafting is commonly used for revascularization or pedicle lengthening. Although veins are more commonly used, they can form aneurysms when bridging an arterial gap. This can lead to thrombosis, and the risk is increased when there is a size discrepancy. This study reports the long-term results of arterial lengthening via size discrepant carotid artery and femoral vein grafts in a rat femoral artery model (1:1.5 ratio). A total of 28 rats were used in this study, divided into two groups of 14. By the 21st day, one anastomosis in each group has been found to be thrombosed. Long-term patency rates were the same for both groups (93.3%). Radiologic imaging showed that size match in the carotid artery grafts was excellent despite of slightly fusiform dilatation, but in the vein groups, pronounced aneurismal deformation and distortion in the anastomosis was seen. Histologic analysis revealed that in the arterial grafts, endothelial continuity was smooth and mural inflammation was less than that of the vein grafts. Organized or recanalized mural thrombi were seen in 38.5% in the vein grafts, whereas in arterial grafts there were none.
    Journal of Reconstructive Microsurgery 07/2013; · 1.00 Impact Factor
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    ABSTRACT: Hand injuries with multiple metacarpal involvements often include midpalmar muscle, extensor tendon, and skin defects. Reconstruction method is decided according to the type and amount of structures to be restored. Bone reconstruction and resurfacing of the skin is regarded as priority, and restoration of tendon function and joint mobility can be left for further procedures. An ideal flap for such defects should provide bone for multiple metacarpal defects and a large enough skin paddle. Such flaps are few, and one of the most suitable of them all is the free fibular osteoseptocutaneous flap (free FOSCF). In this report, our experience with the use of free FOSCF for reconstruction of the mutilating hand injury in five patients with extensive skin integument and metacarpal involvement has been presented. Total lengths of fibular flaps were averagely 11 cm in length and were divided into averagely 2.4 segments. Average dimensions of the skin paddles were 7.75 × 8.75 cm. Although the nature of the devastating traumas limited the ultimate functional recovery; wound closure, stability, and various degrees of mobility were restored in all patients. In our experience, reconstruction with free FOSCF proved to be an effective tool in mutilating hand injuries with metacarpal involvement. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
    Microsurgery 03/2012; 32(7):520-6. · 1.62 Impact Factor
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    ABSTRACT: Free-tissue transfer is the reconstruction of choice for most head and neck defects. However, pedicled flaps are also used, especially in high-risk patients and after failure of a free flap. The aim of this study was to compare transaxillary-subclavian pedicled latissimus dorsi musculocutaneous (PLDMC) flap, pectoralis major musculocutaneous flap, and free-tissue transfer for head and neck reconstruction in American Society of Anesthesiologists grades II and III patients. During the last 4 years, PLDMC flap with a modified transaxillary-subclavian route for transfer to the neck was used in 8 patients, pectoralis major musculocutaneous flap was used in 7 patients, and free flaps were used in 12 patients for head and neck reconstructions. These 3 methods were compared regarding the flap dimensions, complications, flap outcome scores, hospitalization time, and cost of the treatment. Mean age of the patients, mean American Society of Anesthesiologists scores, mean dimensions of the flaps, and mean hospitalization time did not differ significantly among the 3 groups. Regarding the operation time, flap complications, outcomes, and cost of total treatment, although statistically not significant, PLDMC group offered the fastest reconstruction with highest flap outcome scores and minimum cost. Free-tissue transfer is the procedure of choice especially for functional reconstruction of head and neck region. Occasionally, there exist cases in whom a pedicled flap could offer a safer option. The PLDMC flap transferred via the transaxillary-subclavian route may be preferred than, with advantages including increased arc of rotation, safer pedicle location, shorter duration of the procedure, and reduced complication rates and costs.
    The Journal of craniofacial surgery 05/2010; 21(3):771-5. · 0.81 Impact Factor
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    ABSTRACT: Split-thickness skin grafting (STSG) is a frequently used reconstructive technique but is associated with a large variation regarding the management of the donor site. The aim of this study is to compare five different dressings for management of the STSG donor site in a prospective trial. 100 consecutive patients, in whom reconstruction with STSG was performed, were included into the study. The grafts are harvested in a standard manner and the donor sites were dressed with one of the following materials: Aquacel® Ag, Bactigras® with Melolin®, Comfeel® Plus Transparent, Opsite® Flexigrid and Adaptic®. The materials are compared regarding to the time required for complete epithelialization, pain sensed by the patients, incidence of infection, scar formation, ease of application and the cost. The earliest complete epithelialization was observed for Aquacel® Ag and the latest for Bactigras® with Melolin®·Comfeel® Plus Transparent was the most painless dressing and Bactigras® with Melolin® was the most painful. The incidence of infection was highest for Bactigras® with Melolin®·Opsite® Flexigrid was the most economical dressing and Aquacel® Ag was the most expensive one. The aim is to provide the earliest complete epithelialization with minimal patient discomfort and lower cost in management of the STSG donor sites. None of the tested materials were ideal regarding these criteria, but Comfeel® Plus Transparent, as the least painful and one of the most economical materials, may be offered as the dressing of choice among the tested materials.
    Burns: journal of the International Society for Burn Injuries 04/2010; 36(7):999-1005. · 1.95 Impact Factor
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    ABSTRACT: The objective of this study was to compare the free muscle-musculocutaneous flaps and free perforator skin flaps used for soft tissue reconstruction of the lower extremities. Fifty-three patients whose skin and soft tissue of the lower extremities had been reconstructed were divided into two groups: a perforator flap group, reconstructed using anterolateral thigh (ALT) free flap (23 cases), and a muscle-musculocutaneous flap group, in whom latissimus dorsi and rectus abdominus muscle-musculocutaneous free flaps were used (30 cases). Postoperative complications, long-term results, and donor site morbidities were studied in the two groups. Complete flap survival was 78.3% with four total and one partial flap loss in the ALT group and 90.0% with one total and two partial failure in the muscle-musculocutaneous flap group. Muscle-musculocutaneous flaps were the flaps of choice in Gustillo grade IIIB-C injuries and for reconstruction of more proximal localizations. ALT was preferred in relatively younger patients and was typically used for coverage of the distally localized defects. Flap complication rate was significantly higher in the ALT group, but the overall complication rate was similar between the groups. ALT perforator flap is a precious option for lower extremity soft tissue reconstruction with minimal donor site morbidity. Nevertheless, the beginners should be attentive to an increased rate of flap complications with the ALT flap and free axial muscle-musculocutaneous flaps would still be the tissue of choice for coverage of leg defects for a surgeon before gaining enough experience with perforator flap dissection.
    Microsurgery 09/2009; 30(1):24-31. · 1.62 Impact Factor
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    ABSTRACT: Described in this study is a surgical concept that supports the "consider and use a pedicled perforator flap whenever possible and indicated" approach to reconstruct a particular skin defect. The operation is entirely free-style; the only principle is to obtain a pedicled perforator flap to reconstruct the defect. The perforators are marked with a hand-held Doppler probe and multiple flaps are designed. The appropriate flap is elevated after identifying the perforator(s). Dissection of the perforator(s) or complete incision of the flap margins are not mandatory if the flap is mobilized adequately to cover the defect. Defects measuring 3 x 3 cm up to 20 x 20 cm at diverse locations were successfully reconstructed in 20 of 21 patients with 26 flaps. Pedicled perforator flaps offer us reliable and satisfactory results of reconstruction at different anatomic territories of the body. It sounds more practical and creative to use a free-style manner during pedicled perforator flap surgery, instead of being obliged to predefined templates for this type of procedure.
    Annals of plastic surgery 07/2009; 63(2):179-83. · 1.29 Impact Factor
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    ABSTRACT: Three-dimensional multislice spiral computed tomographic angiography (3D-MSCTA) is a minimally invasive method of vascular mapping. The aim of this study was to evaluate the clinical usefulness of this imaging technique in delineating the recipient vessels for safer free tissue transfer to complicated regions. 3D-MSCTA was performed preoperatively in 26 patients scheduled for free tissue transfer, in whom the availability of the recipient vessels were considered to be uncertain, and 23 of these were operated on. Radiographic and operative findings regarding the availability of the recipient vessels for anastomosis were correlated in 21 of these 23 patients. 3D-MSCTA yielded two false-positive results; anastomosis was not possible because of widespread atherosclerotic plaques and poor flow observed in the recipient arteries despite the good caliber observed in 3D-MSCTA images. 3D-MSCTA provides a noninvasive means of preoperatively assessing recipient site vessels for anatomic variations and suitability before free tissue transfer and enables the surgeon to establish an appropriate treatment plan. But it is not 100% reliable yet and the possibility of false-positive results should be kept in mind, especially inthe patients with peripheral vascular disease. 3D-MSCTA has the potential to replace digital subtraction angiography for planning of microvascular reconstructions and newer devices with higher resolutions will probably increase the reliability of this technique. (c) 2009 Wiley-Liss, Inc. Microsurgery, 2009.
    Microsurgery 05/2009; 29(7):536-40. · 1.62 Impact Factor
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    ABSTRACT: Delayed sural flap based on the vascular axis of the sural nerve has been advocated for coverage of diabetic foot ulcers. In this study we compared the survival of neurovenous and standard inferior epigastric island flaps in diabetic and non-diabetic rats. VEGF concentrations and electrolyte balance of the flaps were also investigated during elevation and on the fifth day to explore the possible mechanisms that influence ischaemia of the flap during the hyperglycaemic state. There were no statistical differences in area surviving between diabetic and control rats for either flap. The VEGF concentrations were also similar in the two flaps in the two groups during elevation. On the fifth day, VEGF concentrations had decreased significantly in all of the flaps. Electrolyte balance paralleled VEGF concentrations. We conclude that flaps based on the vascular axis of a superficial nerve deserve further experimental and clinical attention as potential options for reconstruction of ulcers on diabetic feet.
    Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery 02/2007; 41(1):22-5. · 0.94 Impact Factor
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    ABSTRACT: Perforator flaps increasingly find acceptance and use in the field of reconstructive surgery due to their decreased donor-site morbidity and increased like-tissue coverage. Nevertheless, they are more prone to vascular compromise, especially when the meticulous technique they require is not employed. Pedicle twisting is a condition occasionally encountered in flap procedures, sometimes inadvertently, sometimes inevitably. In this study, circulatory comprise induced by twisting of the pedicle on a true perforator flap in a rat model is investigated.Thirty-eight Wistar-Albino rats were randomized into 4 groups, and cranial epigastric artery true perforator flaps were elevated on a single perforator. The flaps were returned as they were in the control group (n = 9), and with 90 degrees , 180 degrees , and 270 degrees of torsion in groups 2 (n = 9), 3 (n = 10), and 4 (n = 10), respectively. The flaps were evaluated by their flap survival area, weight, and histopathological appearance by the end of the first week. The mean flap survival ratios for groups 1, 2, 3, and 4 were 97.78 +/- 4.41%, 72.22 +/- 44.10%, 73.50 +/- 30.46%, and 30 +/- 30.18% (mean +/- SD), respectively. The degree of degenerative changes in group 4 was found to be statistically significant (P < 0.016).Our histopathological examinations indicate that vascular compromise was moderate in group 3 and severe in group 4. Our findings suggest that under normal conditions, the pedicle of a true perforator flap must not be twisted more than 180 degrees .
    Annals of Plastic Surgery 02/2006; 56(2):186-9. · 1.38 Impact Factor
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    ABSTRACT: This article describes a pedicle-lengthening procedure (the Y-V-I principle) that reverts a Y-shaped vascular structure into an I-shaped vascular structure, and its application to the latissimus dorsi muscle. If the Y-shaped vascular structure is divided proximal to the branching point and ligated, it becomes a V-shaped vascular structure. To obtain a linear I-shaped vascular structure, the V is opened, and the length of the vascular pedicle will become equal to the combined length of both limbs of the V. This report indicates that the latissimus dorsi flap may be transferred based on the circumflex scapular artery or the serratus branch.
    Journal of Reconstructive Microsurgery 05/2005; 21(3):173-8. · 1.00 Impact Factor
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    ABSTRACT: The objective of this study was to examine the effects of the standard surgical delay in the flaps based on the cutaneous branches of the vascular axis around a superficial sensory nerve. The delay procedure was experimentally tested in rats and subsequently used in patients. In the experimental study, the survival of a delayed inferior epigastric neurovenous flap was compared with that of a nondelayed inferior epigastric neurovenous flap. One type of clinically applicable delay pattern (standard bipedicled technique) was employed. A 3 x 3 cm flap was raised in 20 female Wistar rats assigned randomly to 2 groups. Each group consisted of 20 flaps. The standard bipedicled delay pattern increased the percentage survival of the delayed inferior epigastric neurovenous flap. The survival percentage of the delayed flaps was 59.8 +/- 185.0 (P < 0.5). The histologic findings of the skin revealed that our delay procedure enhanced the perfusion of the flap by dilating the arterial network. Stimulated by our experimental findings, we used the island bipedicled surgical flap delay or combined strategic-standard delay in the distally pedicled sural flap successfully on 9 cases.
    Annals of Plastic Surgery 12/2004; 53(5):481-7. · 1.38 Impact Factor
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    ABSTRACT: The authors report the application of subcision surgery to ear deformities for crosscutting and weakening of the deformed cartilage. The subcision techniques for correction of a deformed cartilage are divided into two groups. With the first method, termed "horizontal subcision," a 18-gauge needle is inserted horizontally through a puncture in the skin surface, and multiple passes are made. With the second method, termed "vertical subcision," a sweeping motion of the needle is used for crosscutting of the deformed cartilage. An experimental study was conducted using 10 rabbits (20 ears) to test the authors clinical observations. On the basis of histologic analysis, the authors hypothesized that with the horizontal subcision technique, the sharp edge of the needle damages the perichondrium and weakens the cartilage by creating multiple irregular microincisions. With regard to the vertical incision technique, gross examination showed partial or complete cuts of the cartilage. Subcision surgery was successfully used in eight cases.
    Aesthetic Plastic Surgery 07/2004; 28(4):239-44. · 1.26 Impact Factor
  • Ahmet Demir, Lutfi Eroğlu
    Plastic &amp Reconstructive Surgery 07/2003; 111(7):2475. · 3.54 Impact Factor
  • Plastic &amp Reconstructive Surgery 06/2003; 111(6):2116-7. · 3.54 Impact Factor
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    ABSTRACT: Reconstruction options for columellar defects together with membranous septum, nasal base, and upper lip are restricted. We present a case successfully treated with bilateral cheek advancement flaps with upper medial, perialar skin flaps to reconstruct the upper lip, columella, nasal base and membranous septum in a single session. This method provides adequate tissue with minimal cosmetic deformity in a single stage for repairing such compound defects.
    British Journal of Plastic Surgery 05/2003; 56(3):291-2. · 1.29 Impact Factor
  • Plastic &amp Reconstructive Surgery 03/2003; 111(2):942-3. · 3.54 Impact Factor
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    ABSTRACT: For practice in microsurgery, animal models and microsurgical instruments are required. The use of some synthetic and non-animal materials such as human placenta and other tissues have also been suggested for practicing. The other material that is needed is microsuture. These materials are expensive and often not easily obtained. To meet this requirement, the authors present human hair as a microsuture material for microsurgical practice.
    Journal of Reconstructive Microsurgery 02/2003; 19(1):37-40. · 1.00 Impact Factor
  • Plastic &amp Reconstructive Surgery 12/2002; 110(6):1601-3. · 3.54 Impact Factor

Publication Stats

118 Citations
71.70 Total Impact Points

Institutions

  • 2009–2012
    • ONEP Aesthetic-Plastic Surgery Science Institute
      İstanbul, Istanbul, Turkey
  • 2006–2007
    • Ondokuz Mayıs Üniversitesi
      • Faculty of Medicine
      Djanik, Samsun, Turkey