Dr. Ayan graduated from Medical School in 1991 and completed his urology education in 1997. At the beginning of his carrier, he was a post doctorate research fellow at the Department of Urology of Harvard Medical School, Children’s Hospital in Boston (1999-2000). He studied the effect of partial ureteral obstruction to the kidney in early developmental stage in an experimental animal fetus model. This study provided a significant contribution to a complicated issue of pediatric urology and was cited many times by its successors.
He became associate professor of urology in 2004 and was appointed as a professor of urology in 2009. He was accepted as a clinical fellow in Minimal Invasive Urologic Oncology at the Department of Surgery, Section of Urology at the University of Chicago (2014-2015). He worked in an intense oncology program mainly concentrated on robotic surgery of prostate and kidney cancer. Because of this background, he is mainly interested in urologic oncology and pediatric urology. The primary portion of his daily practice consist of kidney cancer, prostate cancer, bladder cancer, neonatal hydronephrosis, ureteropelvic junction obstruction, urine reflux to kidney, hypospadias and undescended testis.
Because of its prevalence in Turkey, Prof. Ayan has a huge experience with urinary stone disease and he is doing large number of endoscopic and percutaneous surgeries for kidney, ureter and bladder stones.
Prof. Ayan holds United States Medical License and European Board of Urology Certificate. He is a member of AUA, EAU and Turkish Urologic Surgery and Urologic Oncology Societies.
List of International Scientific Publications;
1. Ayan S, Yildirim S, Ucar C, Sarioglu Y, Gültekin EY, Butuner C. Corporal reactivity to adenosine and prostaglandin E1 in alloxan-induced diabetic rabbit corpus cavernosum and the effect of insulin therapy. BJU Int, 83: 108-12, 1999.
2. Yildirim S, Ayan S, Sarioglu Y, Gültekin EY, Butuner C. The effects of long-term oral administration of L-arginine on the erectile response of rabbits with alloxan-induced diabetes. BJU Int, 83: 679-85, 1999.
3. Ayan S, Kaloglu C, Gökce G, Kılıcarslan H, Gültekin EY. Effect of insulin therapy to diabetic cystopathy: urodynamic and histological findings in a rabbit model. Sc J Urol Nephrol, 33: 392-5, 1999.
4. Yildirim S, Ayan S, Sarioglu Y, Gültekin Y, Uma S. Does diabetes mellitus affect the progress of tolerance to isosorbide dinitrate (ISDN) in corporal tissue? Nitric Oxide: Biology and Chemistry, 4: 29- 34, 2000.
5. Ayan S, Sarioglu Y, Yildirim S, Gokce G, Bagcıvan I. Relaxation induced by omeprazole does not change in diabetic rabbit corpus cavernosum. BJU Int, 87(3):265-8, 2001.
6. Ayan S, Gokce G, Kılıcarslan H, Kaya K, Gultekin EY. An unusual cause of urinary incon tinence: urethral coitus. Sc J Urol Nephrol, 35:254, 2001.
7. Yildirim S, Simsek R, Ayan S, Gokce G, Sarıoğlu Y, Safak C. Relaxant effect of some benzothiazolinone dervatives on isolated rabbit corpus cavernosum. Urol Res, 29:182-5, 2001.
8. Ayan S, Roth JA, Freeman MR, Bride SH, Peters C. Partial ureteral obstruction dysregulates the RAS in the fetal sheep. Urology, 58: 301-6, 2001.
9. Kılıcarslan H, Ayan S, Gokce G, Kaya K, Gultekin EY. Cranial blind ending branch of a bifid ureter. Int Urol Nephrol, 32: 635-6, 2001.
10. Gokce G, Kılıcarslan H, Ayan S, Yıldız E, Kaya K, Gultekin EY. Adenomatoid tumors of testis and epididym: a report of two cases. Int Urol Nephrol, 32:677-80, 2001.
11. Ayan S, Gokce G, Kılıcarslan H, Ozdemir O, Yildiz E, Gultekin EY. K-RAS mutation in transitional cell carcinoma of urinary bladder. Int Urol Nephrol, 33:363-67, 2001.
12. Bulut HE, Onarlıoglu B, Kaloglu C, Özdemir Ö, Ayan S. Effects of experimental diabetes and insulin treatment on rabbit renal morphology: a quantitative and qualitative study. Turk J Med Sci, 31: 209-16, 2001.
13. Kılıcarslan H, Gokce G, Ayan S, Gultekin EY, Arıkan Y, Hocaoglu S. Fournier’s gangrene: a report of 20 cases. T Klin J Med Res 19:55-58, 2001.
14. Gokce G, Kılıcarslan H, Ayan S, Tas F, Akar R, Kaya K, Gultekin EY. Genitourinary tuberculosis: A review of 174 cases. Scand J Infect Dis, 34: 338-40, 2002.
15. Kilicarslan H, Yildirim S, Bagcivan I, Ayan S, Sarac B, Sarioglu Y. Effect of chronic renal failure (CRF) on purinergic responses of corpus cavernosal smooth muscle in rabbits. BJU Int 90(6):596-600, 2002.
16. Bagcivan I, Gokce G, Ayan S, Yildirim S, Sarac B, Kilicarslan H, Sarioglu Y. Hydrogen-potassium ATPase inhibitors induce relaxation on rabbit prostatic strips in vitro.Int J Urol.;9(11):641-4; discussion 645, 2002.
17. Bagcivan I, Kilicarslan H, Sarac B, Gokce G, Yildirim S, Ayan S, Sarioglu Y. The evaluation of the effects of renal failure on erectile dysfunction in a chronic renal failure (CRF) rabbit model. BJU Int.;91(7):697-701, 2003
18. Kilicarslan H, Guvenal T, Ayan S, Gokce G, Cetin A, Gultekin Y. Comparison of outcomes of three different surgical techniques performed for stress urinary incontinence. Int J Urol.;10(3):126- 30, 2003.
19. Kaya S, Poyraz O, Gökçe G, Kılıçarslan H, Kaya K and Ayan S. Role of Genital Mycoplasmata and Other Bacteria in Urolithiasis. Scand J Infect Dis, 35:315-317,2003.
20. Kilicarslan H, Gokce G, Ayan S, Atalar M, Kaya S, Kaya K, Gultekin Y. A case of hydatid disease: urinary retention due to isolated retrovesical hydatid cyst in a boy. Scand J Infect Dis, 35 :408-410, 2003.
21. Gokce G, Kaya K, Kılıcarslan H, Tas F, Ayan S, Yıldız E, Gultekin E Y. Epidermoid cyst in the renal pelvis. Int Urol Nephrol;35(1):9-10, 2003.
22. Kilicarslan H, Gokce G, Ayan S, Guvenal T, Kaya K, Gultekin EY. Predictors of outcome after in situ anterior vaginal wall sling surgery. Int Urogynecol J Pelvic Floor Dysfunct ;14(5):339-41, 2003.
23. Kilicarslan H, Gokce G, Kaya K, Ayan S, Gultekin YE. Surgical treatment of penil fractures. Ulus Travma Derg.;9(1):54-6, 2003.
24. Yildiz E, Gokce G, Kilicarslan H, Ayan S, Goze F, Gultekin EY. Prognostic value of the expression of Ki-67, CD44 and vascular endothelial growth factor, and microvessel invasion, in renal cell carcinoma. BJU Int. 2004 ;93(7):1087-93.
25. Gokce G, Topsakal K, Ayan S, Kilicarslan H, Gokce SF, Gultekin EY. Case report: Nonobstructive giant urethral stone with two safety pins. Int Urol Nephrol. 2004;36(1):65-6.
26. Kaya K, Ayan S, Gokce G, Kılıcarslan H, Yildiz E, Gultekin EY. Urinary nuclear matrix protein 22 for diagnosis of renal cell carcinoma. Scand J Urol Nephrol. 38 :1-5,2004.
27. Ayan S, Kaya K, Topsakal K, Kılıçarslan H, Gokce G, Gültekin Y. Efficacy of tolterodine as a firstline treatment for non-neurogenic voiding dysfunction in children. BJU Int. 96(3):411-4, 2005.
28. Kaya K, Gokce G , Kaya S, Kilicarslan H, Ayan S, Gultekin EY. Isolated renal and retropertoneal hydatid cysts: a report of 23 cases. Trop Doct. 2006 Oct;36(4):243-6.
29. Candan F, Ayan S, Tas F, Gokce G, Elagoz S. Spontaneous renal laceration as the presenting feature of polyarteritis nodosa in a patient with familial Mediterranean fever after hepatitis A infection. Rheumatol Int, 25(6):475-7, 2005.
30. Silig Y, Pinarbasi H, Gunes S, Ayan S, Bagci H, Cetinkaya O. Polymorphisms of CYP1A1, GSTM1, GSTT1, and prostate cancer risk in Turkish population. Cancer Invest, 24(1):41-5, 2006.
31. Tanzer F, Ozgur A, Bardakci F, Cankorkmaz L, Ayan S. Analysis of a 1-year-old cystinuric patient with recurrent renal stones. Int J Urol. 13(10):1347-9, 2006.
32. Kilicarslan H, Ayan S, Vuruskan H, Gokce G, Gultekin EY.Treatment of detrusor sphincter dyssynergia with baclofen and doxazosin. Int Urol Nephrol. 2006;38(3-4):537-41.
33. Ayan S, Topsakal K, Gokce G, Gultekin EY.Efficacy of combined anticholinergic treatment and behavioral modification as a first line treatment for nonneurogenic and nonanatomical voiding dysfunction in children: a randomized controlled trial. J Urol. 2007 Jun;177(6):2325-8; discussion 2328-9.
34. Ozdemir O, Gul E, Kilicarslan H, Gokce G, Beyaztas FY, Ayan S, Sezgin I.SRY and AZF gene variation in male infertility: a cytogenetic and molecular approach. Int Urol Nephrol. 2007;39(4):1183-9.
35. Yildiz E, Ayan S, Goze F, Gokce G, Gultekin EY. Relation of microvessel density with microvascular invasion, metastasis and prognosis in renal cell carcinoma. BJU Int. 2008 Mar;101(6):758-64.
36. Kenan Kaygusuz, Gokhan Gokce, Iclal Ozdemir Kol, Semih Ayan and Sinan Gursoy. Efficacy of Preventive Analgesia with Tramadol or Lornoxicam for Percutaneous Nephrolithotomy: A Prospective, Randomized, Double-Blind, Placebo-Controlled Study. Current Therapeutic Research 68(4), 205-216, 2007.
37. Kaygusuz K, Gokce G, Gursoy S, Ayan S, Mimaroglu C, Gultekin Y.A comparison of sedation with dexmedetomidine or propofol during shockwave lithotripsy: a randomized controlled trial. Anesth Analg. 2008 Jan;106(1):114-9.
38. Gokce G, Karboga H, Yildiz E, Ayan S, Gultekin Y. Effect of angiotensin-converting enzyme inhibition and angiotensin II type 1 receptor blockade on apoptotic changes in contralateral testis following unilateral testicular torsion. Int Urol Nephrol. 2008;40(4):989-95.
39. Ozdemir, O (Ozdemir, Oztuerk); Yildiz, E (Yildiz, Esin); Ayan, S (Ayan, Semih); Gul, E (Gul, Eylem)1; Gokce, G (Gokce, Goekhan); Yildiz, F (Yildiz, Fazilet)1; Koksal, B (Koksal, Binnur)1; Goze, F (Goze, Fahrettin); Gultekin, EY (Gultekin, E. Yener). Epigenetic alterations and oncogenes mutations in urinary bladder carcinomas.CHROMOSOME RESEARCH. 2009, Volume: 17 Supplement: 1 Pages: 171-171
40. Eskicorapci SY, Türkeri L, Karabulut E, Cal C, Akpinar H, Baltaci S, Baykal K; Turkish Validation Study Group of Kattan Preoperative Nomogram, Kattan MW, Ozen H. Collaborators: Yildirim A, Yazici S, Divrik RT, Ozkardeş H, Koşan M, Kurtuluş FO, Büyükalpelli R, Mungan A, Lekili M, Sahin H, Günlüsoy B, Ayan S, Bozlu M. Validation of two preoperative Kattan nomograms predicting recurrence after radical prostatectomy for localized prostate cancer in Turkey: a multicenter study of the Urooncology Society. Urology. 2009 Dec;74(6):1289-95.
41. Ozdemir O, Yildiz S, Ayan S, Gül E, Gokce G, Yildiz F, Koksal B. Promoter hypermethylation of tissue specific tumor supressor genes and point mutation in K-ras, c-myc proto-oncogenes in urinary (transitional cell) bladder carcinoma. Health. 2010; 2(8):850-856.
42. Türkeri L, Tanıdır Y, Çal Ç, Özen H, Şahin H; Collaborators :Kaya C, Karaman İ, Şengör F, Alkibay T, Sözen S, Büyükalpelli R, Can C, Kuyumcuoğlu U, Albayrak S, Abay E, Soyupak B, Tansuğ Z, Fazlıoğlu A, Gültekin Y, Ayan S, Gümüş E, Lekili M, Dillioğlugil Ö, Özer G, Uygur C, Akpınar H. Comparison of the efficacy of single or double intravesical epirubicin instillation in the early postoperative period to prevent recurrences in non-muscle-invasive urothelial carcinoma of the bladder: prospective, randomized multicenter study. Urol Int. 2010;85(3):261-5.
43. Kuzgunbay B, Yaycioglu O, Soyupak B, Atay Kayis A, Ayan S, Yavascaoglu I, Cal C, Beduk Y; Turkish Study Group of Public Awareness in Testicular Cancer Public awareness of testicular cancer and self-examination in Turkey: A multicenter study of Turkish Urooncology Society.Urol Oncol. 2011 Mar 22. Epub ahead of print]
44. Biçer H, Korgali E, Gökçe G, Ayan S, Yıldırım S, Gültekin EY. Contractile responses of urinary bladder in an experimental model of chronic renal failure. Bosn J Basic Med Sci. 2012 Nov;12(4):219- 23.
45. Yaycioglu O, Eskicorapci S, Karabulut E, Soyupak B, Gogus C, Divrik T, Turkeri L, Yazici S, Ozen H; Society of Urooncology Study Group for Kidney Cancer Prognosis. A preoperative prognostic model predicting recurrence-free survival for patients with kidney cancer. Jpn J Clin Oncol. 2013 Jan;43(1):63-8.
46. Erden Y, Korgalı E, Dundar G, Ayan S, Gokce G, Yildirim S, Gultekin EY. In-vitro effects of PDE5 inhibitor and statin treatment on the contractile responses of experimental MetS rabbit's cavernous smooth muscle. Arch Ital Urol Androl. 2014 Mar 28;86(1):33-8.