The aim of this study was to investigate the biomechanical differences between human dura mater and dura mater substitutes to optimize biomimetic materials. Four groups were investigated. Group I used cranial dura mater (n=10), group II used Gore-Tex® Expanded Cardiovascular Patch (W.L. Gore & Associates Inc., Flagstaff, AZ, USA) (n=6), group III used Durepair® (Medtronic Inc., Goleta, CA, USA) (n=6), and group IV used Tutopatch® (Tutogen Medical GmbH, Neunkirchen am Brand, Germany) (n=6). We used an axial compression machine to measure maximum tensile strength. The mean tensile strengths were 7.01±0.77 MPa for group I, 22.03±0.60 MPa for group II, 19.59±0.65 MPa for group III, and 3.51±0.63 MPa for group IV. The materials in groups II and III were stronger than those in group I. However, the materials in group IV were weaker than those in group I. An important dura mater graft property is biomechanical similarity to cranial human dura mater. This biomechanical study contributed to the future development of artificial dura mater substitutes with biomechanical properties similar to those of human dura mater.

The primary aim of this investigation was to explore the nature of dura mater biomechanics following the introduction of puncture defect(s). Twenty-eight dura mater specimens were collected during autopsy from the department of forensic medicine of the authors' institution. Specimens were divided randomly into one of four groups : group I (cranial dura mater; n=7), group II (cranial dura mater with one puncture defect; n=7); group III (cranial dura mater with two puncture defects; n=7), and group IV (cranial dura mater with three puncture defects; n=7). The mean±standard deviation tensile strengths of the dura mater were 8.35±3.16, 8.22±3.32, 7.13±1.77, and 6.94±1.93 MPa for groups I, II, III, and IV, respectively. There was no statistical difference between all groups. A single, two or more punctures of the dura mater using a 20-gauge Quincke needle did not affect cranial dura tensile strength. This biomechanical study may contribute to the future development of artificial dura mater substitutes and medical needles that have a lower negative impact on the biomechanical properties of dura mater.

Introduction: Dural closure preference has been a topic of debate in contemporary neurosurgery. This study aims to compare different closure techniques using an in vitro model. Methods: Human cadaveric dura mater was attached to a cylindrical metal glass filled with blue dyed saline. A 1 cm dural incision was made. Dural closure was performed using three different techniques. Each group had six samples: Group I – interrupted simple 4-0 polyglactin suture (S) only, Group II – S plus on lay collagen graft, Group III – S plus fibrin sealant. In Group NS, a 1 cm × 1 cm dural window was made. An onlay collagen graft was used with no suturing for this group to serve as an overtly weak reconstruction reference. Primary and secondary leak pressures were recorded (PLP and SLP, respectively). Results: All groups (I–III) had significantly higher PLP and SLP than Group NS. PLP was significantly higher in Group III as compared to groups I and II. Groups I and II had similar PLP values. SLP was similar in all three groups. Conclusion: In this study, the use of fibrin sealant has proven to be the best option in preventing dural leak. However, no technique was superior in the case of SLP.

Background/aim: Application fields of bone tissue engineering studies continue to expand. New biocompatible materials aimed to improve bone repairment and regeneration of implants are being discovered everyday by scientists, engineers, and surgeons. Our objective in this study is to combine polylactic acid which is a polymer with hydroxyapatite in the repairment of bone defects considering the increased need by medical application fields. Materials and methods: After 750 g of PLA with a diameter of 2.85 mm was granulated into minimum particles, these particles were homogenously mixed with hydroxyapatite prepared in laboratory environment. Using this mixture, HA-PLA filament with a diameter of 2.85 mm was prepared in the extrusion device in Kutahya Medical Sciences University Innovative Technology Laboratory. The temperature was 250 degrees C and the gearmotor speed was 9 rpm during extrusion. X-ray diffraction (XRD) analysis was made for crystal phase analyses of the produced hydroxyapatite powder, to determine the produced main phase and examine whether a minor phase occurred. Vickers microhardness test was applied on both samples to measure the endurance levels of the samples prepared with HA-PLA filament. A loading force of 10 kg was applied on the samples for 10 s. Results: Hydroxyapatite peaks in XRD spectrum of the sample presented in figures are concordant with Joint Committee on Powder Diffraction Standards, JCPDS - File Card No. 01-075-9526 and no significant minor phase was observed. For both samples, hardness value was observed to increase between 3 and 5 mm. Conclusion: Surfacing hydroxyapatite on metallic materials is possible. By similar logic, to increase durability with low cost, characteristics of biomaterials can be improved with combinations such as hydroxyapatite PLA. Thus, we found that while these materials have usage limitations due to present disadvantages when used alone, it is possible to increase their efficiency and availability through different combinations.

The aim of this study was to evaluate the olfactory function of patients who had undergone endoscopic transsphenoidal pituitary surgery. In this prospective study, the “Sniffin’ Sticks” test was performed between June 2016 and April 2017 at Izmir Katip Celebi University Ataturk Training and Research Hospital. Thirty patients who were scheduled to undergo endoscopic transsphenoidal pituitary surgery were evaluated preoperatively and 8 weeks postoperatively using the Sniffin’ Sticks test battery for olfactory function, odor threshold, smell discrimination, and odor identification. The patients were evaluated preoperatively by an otolaryngologist. The patients’ demographic data and olfactory functions were analyzed with a t test and Wilcoxon-labeled sequential test. The study group comprised 14 women (46.7%) and 16 men (53.3%) patients. The mean age of the patients was 37.50 ± 9.43 years (range: 16–53 years). We found a significant difference in the preoperative and postoperative values of the odor recognition test (P = 0.017); however, there was no significant difference between the preoperative and postoperative odor threshold values (P = 0.172) and odor discrimination values (P = 0.624). The threshold discrimination identification test scores were not significant (P = 0.110). The olfactory function of patients who were normosmic preoperatively was not affected postoperatively. This study shows that the endoscopic transsphenoidal technique for pituitary surgery without nasal flap has no negative effect on the olfactory function.