Person: ERMERAK, NEZİH ONUR
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ERMERAK
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NEZİH ONUR
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Publication Open Access Esophageal perforation during intragastric balloon therapy: management of a patient with late referral(2023-01-01) ERMERAK, NEZİH ONUR; UPRAK, TEVFİK KIVILCIM; LAÇİN, TUNÇ; YILDIZELİ, BEDRETTİN; YEGEN, ŞEVKET CUMHUR; ERMERAK N. O., Uprak K. T., Emran M., LAÇİN T., YILDIZELİ B., YEGEN Ş. C.Minimally invasive treatment modalities like intragastric balloon therapy (IBT) gained popularity in the treatment of obesity [1]. Some morbidities have been reported in the literature, but it is limited. Esophageal perforation is the most feared complication of the procedure. Although endoscopic stent placement can be chosen as a treatment option in stable patients, most of the patients are treated with surgical drainage and primary repair [2]. We report an unusual case of intragastric balloon placement complicated with esophageal perforation which was successfully treated with a surgical approach after late referral.Publication Open Access Clinical validation of an activity-based enzyme assay for early stage lung cancer(2023-06-02) ERMERAK, NEZİH ONUR; Dempsey P., Sandu Aparacio C., Gonzalezirias R., Hantula S., Kagawa M., Bossmann S. H., Covarrubias-Zambrano O., Nagji A. S., Veeramachaneni N. K., ERMERAK N. O., et al.Background: The USPSTF guidelines recommend annual LDCT scans for 15.5 million adults with a heavy smoking history. While LDCT can reduce deaths by 20%, screening compliance remains low. A blood test with clinically useful, cost effective performance could improve compliance and access when integrated with the standard of care. We describe here a lyophilized nanosensor system for detecting protease enzyme activity in sera with clinically useful diagnostic activity in early stage lung cancer. We evaluated the performance of the assay by examination of prospectively collected sera for detection of cancer in high risk patients. Methods: Sera were obtained in multiple independent studies to include pathologically confirmed, treatment naive lung cancer patients and LDCT confirmed negative individuals. Protease activity was measured on 18 different nanosensors built with protease targets mainly selective for members of the Matrix Metalloproteinase and Cathepsin families. Lyophilized plates were incubated with serum and enzyme activity was measured indirectly as a continuous variable by a fluorescent plate reader. A machine learning modeling tool (Emerge) was used to detect signal associated with a cancer “fingerprint” of protease activity. The analysis stratified allocation into training and testing sets of 250 samples each and reserved a third out of sample validation set (250 samples) for reporting. Results: 750 clinical samples included 30% lung cancers, 63% males, 91% smokers, and an average age of 63 years (SD=9). Cancer cases were distributed across stages I (41%), II (17%), III (20%) and IV (20%) with 5% unknown. Histological classification included 59% adenocarcinoma, 31% squamous cell and 11% other subtypes. Using an Emerge model with only nanosensor activity and gender as inputs, we evolved a balanced algorithm. The algorithm can be further modified to favor sensitivity or specificity depending on the application by applying model weighting factors. We report the performance observed in the 250 out of sample validation set at three points on this spectrum (Table). Among Stage I cancer samples, the balanced algorithm had an accuracy of 90% (26/29). Conclusions: Current LDCT tools show low compliance. We demonstrate clinical validity of a cost effective tool to detect lung cancer in support of LDCT screening. Based on a simple blood sample, the current test may predict early stage lung cancer with an accuracy of 90%. The performance suggests applications in LDCT compliance, post LDCT management, and eventually screening. A clinically validated version of this technology is being evaluated as a triage tool for LDCT screening.Publication Open Access The angiogenic gene profile of pulmonary endarterectomy specimens: Initial study(2023-01-01) ERMERAK, NEZİH ONUR; YILMAZ, BETÜL; BATIREL, SAİME; OLGUN YILDIZELİ, ŞEHNAZ; KOCAKAYA, DERYA; MUTLU, BÜLENT; YILDIZELİ, BEDRETTİN; ERMERAK N. O., YILMAZ B., BATIREL S., OLGUN YILDIZELİ Ş., KOCAKAYA D., MUTLU B., Tas S., YILDIZELİ B.© 2023 The Author(s)Objectives: The underlying mechanisms for the development of chronic thromboembolic pulmonary hypertension and prognostic biomarkers are not clear yet. Thus, our aim is to assess and identify new biomarkers for the expression of 84 key genes linked to angiogenesis. Methods: Patients who had levels more than 1000 dynes·sec·cm−5 were included in the test group, and the other patients were included in the control group. Twelve specimens were taken from the patients. RT2 Profiler PCR Array (Qiagen) was used to quantify the expression of the 84 key genes. Results: Eight patients (6 male, 2 female, median age 54.4 ± 13.1 years) who underwent pulmonary endarterectomy were included. Pulmonary vascular resistance improved significantly from 811 ± 390 dyn/s/cm−5 to 413.3 ± 144.9 dyn/s/cm−5 (P .005) after surgery. Median length of hospital stay was 11.62 ± 2.97 days. The test group had a distinct pattern of impaired angiogenic and antiangiogenic genes. The expression levels of TGFA, TGFB1, THBS2, THBS1, TGFBR1, SERPINE1, SERPINF1, TGFB2, TIMP2, VEGFC, IFNA1, TNF, CXCL10, NOS3, IGF1, and MMP14 were downregulated in the specimens from the patients who had higher pulmonary vascular resistance values, whereas some genes, including PDGFA, showed upregulation that was statistically nonsignificant in the same group. Conclusions: These results can lead to the development of new markers that could predict adverse outcomes of patients with CTEPH. Identification of new markers that are related to worse outcomes would enable screening patients for early diagnosis and treatment.Publication Open Access Production of 3D-printed ribs with a novel material (Nylon 680 Co-Polymer) for chest wall reconstruction on a pig model: Preliminary results of an experimental study(2023-09-01) ERMERAK, NEZİH ONUR; LAÇİN, TUNÇ; ERBARUT SEVEN, İPEK; ERMERAK N. O., YÜKSEL M., Yüksel B., LAÇİN T., ERBARUT SEVEN İ., LAÇİN B.Aim: Three-dimensional (3D) printing has gained popularity among all fields of science in recent years. New research studies about the utilization of 3D printing in the medical field, in terms of medical devices and implants, have been published recently. We tried to adapt this technology into thoracic surgery by implanting 3D produced ribs following chest wall resection with a novel material called Nylon 680 Co-Polymer. We, hereby, present the preliminary results of this experimental study. Materials and Methods: We ordered multi detector computerized tomography of the chest for 2 pigs. We measured the area that we planned to resect on chest wall and used the data for printing custom-made rib for the reconstruction of the resected area. Then, we produced ribs with a USA Food and Drug Administration approved material called Nylon 680 Co-polymer (Taulman 3D, Saint Peters, MO, USA) by using 3D printer (Afinia H480, Chanhassen, MO, USA). Pigs were operated under general anesthesia and the resected areas were reconstructed with custom-made 3D printed ribs. Results: One of the pigs passed away due to myocardial infarction while waking up from anesthesia. We followed up the other pig for 45 days. Then, we sacrificed the animal and resected the operated part for histopathological evaluation. Histopathologic evaluation revealed moderate chronic inflammation with few giant cells containing pigmented foreign bodies. Conclusion: Although we need more studies, it is an important step for adapting 3D-printing into thoracic surgery. Additionally, it is important to identify a potential new material (Nylon 680 Co-polymer) for the future studies. We can use this new material for 3D-printed implant and mesh production, which enables us to produce custom-made products with lower cost in shorter timePublication Open Access Modification of the Nuss procedure: The crossed bar technique for new subtypes of pectus excavatum(2023-05-01) ERMERAK, NEZİH ONUR; ERMERAK N. O., Yuksel M.BackgroundWe aim to describe four new subtypes of PE in detail and represent modification of the Nuss procedure called crossed bar technique for their optimum correction with good results.Methods101 patients who underwent crossed bar technique between August 2005 and February 2022 were included into the study.ResultsThe mean age of the patient series was 21.1 (range 15-38 years) years. Mean Haller index was 3.87. Mean operation duration was 86.84 min. 2 bars were used in 74 (73.3%) of the patients whereas 3 bars were preferred in 27 (26.7%) of them. Mean hospital stay was 4.1 (2-8) days, and all the patients were seen routinely on postoperative follow-up at 1st, 6th, and 18th months. Quality of life questionnaires revealed satisfaction.ConclusionsCross bar technique yields satisfactory results for these new subtypes and can be performed safely with good results in these selected group of patients.Publication Open Access ‘Short Bars Crossed’ to Remodel the Entire Chest Wall in Children and Adolescents with Pectus Excavatum(2024-01-01) ERMERAK, NEZİH ONUR; YÜKSEL, MUSTAFA; Weinhandl A. C., ERMERAK N. O., YÜKSEL M., Rebhandl W.Background: The cross-bar technique of minimally invasive pectus excavatum (PE) correction remains underreported, which is especially true of pediatric patients. We therefore reviewed the experience of a Turkish and an Austrian center. An additional novelty characterizing both pediatric cohorts was the use of short bars. Methods: In a retrospective study, pediatric PE corrections involving ‘short bars crossed’ were analyzed for complications and intra-/postoperative outcomes. Cases with two or three bars were included, given that a horizontal third bar was placed whenever considered useful for upper-chest elevation. All bars were fitted with a single stabilizer near the surgical entry point. In the Austrian center, intercostal nerve cryoablation was used for pain management. Descriptive statistics are presented. Results: Seventy-eight patients ≤18 years old were evaluable at the Turkish (n = 56) and Austrian (n = 22) centers. Total median values were 16.2 (IQR: 15.1–17.4) years for age and 4.60 (IQR: 3.50–6.11) for Haller index. Ten mild or moderate complications (12.8%) were observed, including just one revision requirement due to bar migration (1.28%). Intercostal nerve cryoablation (n = 13) was associated with longer surgical procedures at 150 (IQR: 137–171) versus 80 (IQR: 60–100) minutes but with shorter hospital stays, given an IQR of 3–4 days versus 4–5 days. Conclusion: ‘Short bars crossed’—with a single stabilizer in a ventral position close to the surgical entry point—ensure a wide distribution of forces, protect against bar migration, are safe and effective, and offer stability at an age characterized by growth and physical activity. Level of Evidence: IV.