Assoc. Prof. Dr. Çağatay Ak

Research and Publications

• Ak Ç, Adalı G, Sayar S, Ağaçkıran A, Kulalı F, Kahraman R, Öztürk O, Özdil K. (2022). Portal Vein Thrombosis Risk Factors in Liver Transplant Candidates. Hepatology Forum, 3(3), 88–92. DOI: 10.14744/hf.2022.2022.0005.
• Ak Ç, Sayar S, Tarıkçı Kılıç E, Kahraman R, Öztürk O, Özdil K. (2023). The Role of Self-Expandable Metallic Stents in the Treatment of Malignant Strictures in All Segments of the Gastrointestinal Tract. Indian Journal of Palliative Care, 29(1), 64–69. DOI: 10.25259/IJPC_106_2021.
• Ak Ç, Sayar S, Adalı G, Özdil K. (2022). Acute Severe Ulcerative Colitis After mRNA Coronavirus Disease 2019 Vaccination: Can mRNA Vaccines Unmask Inflammatory Bowel Diseases? ACG Case Reports Journal, 9(7). DOI: 10.14309/crj.0000000000000806.
• Ak Ç, Sayar S, Polat ZP, Tarıkçı Kılıç E, Özdil K. (2021). Clinical and Laboratory Factors Associated with Severe Disease Course in Turkish Patients with SARS-CoV-2 Infection. Iranian Red Crescent Medical Journal, 23(2). DOI: 10.32592/ircmj.2021.23.2.283.
• Ak Ç, Kahraman R, Sayar S, Tarıkçı Kılıç E, Adalı G, Özdil K. (2023). Prediction of Prognosis in Acute Pancreatitis with Inflammatory Markers and Patient Characteristics Compared to the Scoring System: Real-Life Data. The Medical Bulletin of Şişli Etfal Hospital, 57(2), 182–188. DOI: 10.14744/SEMB.2022.42966.
• Ak Ç, Sayar S, Kahraman R, Özdil K. (2022). Evaluating the Long-Term Outcomes of Medical and Surgical Treatments in Fibrostenotic Crohn’s Disease Patients Treated with Anti-TNF/Biologic Therapy. Experimed, 12(3), 160–167. DOI: 10.26650/experimed.1183920.
• Ak Ç, Sayar S, Adalı G, Özdil K. (2022). Acute Severe Ulcerative Colitis After mRNA Coronavirus Disease 2019 Vaccination: Can mRNA Vaccines Unmask Inflammatory Bowel Diseases? ACG Case Reports Journal, 9(7). DOI: 10.14309/crj.0000000000000806.
• Sayar S, Aykut H, Kaya Ö, Kürbüz K, Ak Ç, Gökçen P, Mutlu Bilgiç N, Adalı G, Kahraman R, Doğanay HL, Özdil K. (2021). Bone Mineral Density Screening and the Frequency of Osteopenia/Osteoporosis in Turkish Adult Patients with Celiac Disease. Turkish Journal of Gastroenterology, 32(7), 600–607. DOI: 10.5152/tjg.2021.20313.
• Sayar S, Ayrancı G, Kürbüz K, Ak Ç, Tarıkçı Kılıç E, Kahraman R, Atalay R, Öztürk O, Çalışkan Z, Adalı G, Doğanay HL, Özdil K. (2020). High Frequency of Gastric Cancer Precursor Lesions in Patients with Gastric Xanthelasma: A Prospective Case-Control Study. European Journal of Gastroenterology & Hepatology, 32(9), 1130–1134. DOI: 10.1097/MEG.0000000000001795.
• Ayan D, Ak Ç. (2023). Bioinformatic Analysis of Genetic Changes in CLOCK, BMAL1, CRY1, CRY2, PER1, PER2, PER3, and NPAS2 Proteins in HCC Patients. Hepatology Forum, 4(3), 108–117. DOI: 10.14744/hf.2023.2023.0009.
• Altunal LN, Özel AS, Ak Ç. (2023). Cytomegalovirus Reactivation in Ulcerative Colitis Patients: Early Indicators. Nigerian Journal of Clinical Practice, 26(6), 765–770. DOI: 10.4103/njcp.njcp_616_22.
• Özdil K, Ak Ç, Sayar S, Aykut H, Tarıkçı Kılıç E. (2022). Can Gastric Botulinum Toxin A Injection Be Used as a Minimally Invasive Procedure in the Short-Term Treatment of Obesity? Journal of Minimal Access Surgery, 18(2), 201–206. DOI: 10.4103/jmas.JMAS_105_2.

Conference Presentations

• Sayar S, Kürbüz K, Ak Ç, Mutlu Bilgiç N, Kahraman R, Demirdağ H, Atalay R, Çalışkan Z, Öztürk O, Doğanay HL, Özdil K. (2019). Hepatitis B Reactivation Rate in Patients Receiving Anti-TNF Therapy: Evaluation of Patients Who Did Not Receive Antiviral Prophylaxis. AASLD–TASL Connect Regional Meeting 2019, p. 38. DOI: 10.5152/tjg.2019.24.
• Ak Ç. (2023). Location and Histopathological Evaluation of Colon Polyps: Single-Center Results. 13th Istanbul Internal Medicine Clinics Meeting.
• Hepatitis B Reactivation Prophylaxis in Patients Receiving Immunosuppressive or Cytotoxic Drugs: Results of a Single-Center Experience.

Awards

• 2022: Best Oral Presentation Award, 39th National Gastroenterology Week Congress, Turkish Society of Gastroenterology.

Research Projects Led or Participated In

• A multicenter, randomized, double-blind, placebo-controlled phase 3 study evaluating the efficacy and safety of elafibranor in patients with nonalcoholic steatohepatitis (NASH) and fibrosis.
• A double-blind, randomized, placebo-controlled phase IIb study evaluating the efficacy and safety of norursodeoxycholic acid tablets in patients with nonalcoholic steatohepatitis (NASH).
• A phase 2, randomized, open-label, multicenter study investigating the efficacy, pharmacokinetics, safety, and tolerability of JNJ-73763989 plus pegylated interferon alfa-2a and nucleos(t)ide analogue therapy, with or without JNJ-56136379, in treatment-naïve patients with HBeAg-positive chronic hepatitis B virus infection (REEF-IT).

Articles Published in International Peer-Reviewed Journals

• Ak Ç, Aykut H, Pala E, Sayar S, Tarıkçı Kılıç E, Adalı G, Kahraman R, Öztürk O, Özdil K. (2022). Post-ERCP Complication Analysis of an Experienced Center. Surgical Laparoscopy, Endoscopy & Percutaneous Techniques, 32(6), 707–713. DOI: 10.1097/SLE.0000000000001113.
• Ak Ç, Sayar S, Tarıkçı Kılıç E, Kahraman R, Öztürk O, Zemheri IE, Özdil K. (2022). EUS-FNA and ROSE in Solid Lesions of the Pancreas: Do They Have the Same Diagnostic Efficacy Across Pancreatic Sites? Northern Clinics of Istanbul, 9(5), 464–469. DOI: 10.14744/nci.2022.79119.
• Ak Ç, Sayar S, Tarıkçı Kılıç E. (2022). A Schistosoma Colitis Case Misdiagnosed as Ulcerative Colitis in a Non-Endemic Area: A Case Report. Iranian Journal of Parasitology, 17(3), 431–435. DOI: 10.18502/ijpa.v17i3.10637.

Additional Conference Presentations

• Ak Ç. (2023). 13th International Congress on Medical and Health Sciences Research. Presentation title not provided.
• Erdem L, Akbal E, Tucer D, Üçbilek E, Şirin G, Alkım H, Ak Ç, Özercan M, Kıyak M, Şenkal İV, Canbakan B, Boynukara C, Candan S, Battaloğlu OK, Cankurtaran RE, Ünal HÜ, Aslan E, Dolapçıoğlu C, Uyanık A, Ahısalı Erim E, Soylu A, Doğanay L, Gürbüz AK, Özdil K, Alagözlü H, Erürker Öztürk T, Çoban M, Sezikli M, Koçak E, Saruç M, Tuncer M, Akyüz F, Tözün N. (2022). The Colorectal Cancer and Polyp Working Group Scoring System: A Reliable, Effective, and Noninvasive Method for Colorectal Cancer Screening in Individuals Under 50. 39th National Gastroenterology Week.
• Ak Ç. (2022). Complications and Their Management in HBV Treatment. 2nd Gastro-Endocrine Summit.
• Ak Ç, Özdil K. (2022). Outcomes of Patients Receiving Self-Expandable Metal Stents (SEMS) for Benign Upper Gastrointestinal Conditions to Maintain Enteral Nutrition. 5th Internal Medicine Congress.
• Ak Ç, Evrensel T. (2021). Prognostic Factors and the Prognostic Significance of PET/CT SUVmax Values in Patients with Non-Small Cell Lung Cancer. 8th International Congress on Medical and Health Sciences Research.
• Ak Ç, Sayar S, Özdil K. (2021). Analysis of Patients Undergoing EUS-Guided Fine-Needle Aspiration for Upper Gastrointestinal Subepithelial Lesions. University of Health Sciences, 5th Gastroenterology Days.
• Ak Ç, Pala E, Sayar S, Kahraman R, Öztürk O, Özdil K. (2021). A Case of PFIC3 Presenting with Recurrent Episodes of Cholangitis. University of Health Sciences, 5th Gastroenterology Days.
• Ak Ç, Aykut H, Pala E, Sayar S, Kahraman R, Özdil K. (2021). Median Arcuate Ligament Syndrome: A Cause of Persistent Abdominal Pain in a Patient with Crohn’s Disease. 10th IBD E-School.
• Ak Ç, Sayar S, Kahraman R, Öztürk O, Özdil K. (2021). Microscopic Colitis: An Alternative Cause of Chronic Diarrhea in a Patient with Celiac Disease. 10th IBD E-School.
• Ak Ç, Sayar S. (2021). Frequency of Osteopenia and Osteoporosis in Our Patients with Inflammatory Bowel Disease. 2nd Gazi Gastroenterology Days — IBD.
• Ak Ç, Aykut H, Pala E, Sayar S, Ünal B, Ağaoğlu NB, Tarıkçı Kılıç E, Kahraman R, Doğanay HL, Özdil K. (2020). A Case of Gardner Syndrome Presenting with Acute Pancreatitis. 37th National Gastroenterology Week. Conference abstract.
• Ak Ç, Sayar S, Aykut H, Mutlu Bilgiç N, Canbak T, Altundal K, Zemheri IE, Çalışkan Z, Kahraman R, Adalı G, Doğanay HL, Özdil K. (2020). A Case of Mucinous Cystic Neoplasm Presenting as an Intraductal Papillary Mucinous Neoplasm (IPMN). 37th National Gastroenterology Week.
• Tarıkçı Kılıç E, Kahraman R, Sayar S, Ak Ç, Özdil K. (2020). Comparison of Two Sedation Methods Used with Bispectral Index Monitoring During Endoscopic Retrograde Cholangiopancreatography. 37th National Gastroenterology Week.
• Kürbüz K, Ak Ç, Sayar S, Mutlu Bilgiç N, Kahraman R, Adalı G, Çalışkan Z, Öztürk O, Gökçen P, Doğanay HL, Özdil K. (2019). A Case of Klatskin Tumor in a Young Patient with Primary Biliary Cholangitis. 16th National Hepatogastroenterology Congress.
• Sayar S, Kürbüz K, Mutlu Bilgiç N, Ak Ç, Çalışkan Z, Kahraman R, Demirdağ H, Atalay R, Öztürk O, Doğanay HL, Özdil K. (2018). Gastric Metastases of Breast Carcinoma: Three Case Reports. 35th National Gastroenterology Week.