Varayu Prachayakul, MD

Assistant Professor
Division of Gastroenterology
Department of Internal Medicine
Faculty of Medicine, Siriraj Hospital, Mahidol University
Bangkok 10700, Thailand



After complete the Clinical fellowship training in advanced therapeutic endoscopy (ERCP) and Endosonography at Interdisciplinary endoscopic unit, University of Hamburg-Eppendorf, Hamburg Germany in 2008, Dr. Prachayakul, been working on advanced therapeutic endoscopy at Siriraj GI Endoscopy center, Siriraj hospital, Mahidol university. He had published some case reports, case series and articles regarding; gastrointestinal bleeding, colon cancer screening, endoscopic ultrasound (EUS) in both diagnosis and therapeutic procedures, endoscopic retrograde cholangiopan creatography (ERCP) which also included cholangioscopy / pancreatoscopy and single balloon assisted enteroscopy. Dr. Prachayakul, currently work on all the treatments and procedures mentioned above. His personal interest are the development of new techniques and accessories to aid the treatments in advanced therapeutic procedures; such as a self-made Teflon catheters for graded dilatation used in EUS guided biliary drainage.

Research Interest

His research interests include: Gastrointestinal bleeding, gastrointestinal malignancy (such as cholangiocarcinoma and pancreatic cancer), ERCP and EUS techniques and instruments, enteroscopy, colon cancer and colon cancer screening.

Scientific Activities


• Award for the outstanding medical student, 1993
• Medical degree with second class honor, 1993


1. Prachayakul V, Jarasjareunwittaya P, Pongprasopchai S, et al. Comparison of clinical, biochemical, virological and histopathological characteristics between chronic hepatitis C infected patients with respect to genotype 1 and 3. Thai J Gastroenterol. 2005; 6: 72-80.
2. Akaraviputh T, Sriprayoon T, Prachayakul V, Sakiyalak P. Endoscopic diagnosis of secondary aortoesophageal fistula. Endoscopy. 2008; 40(Suppl 2): E90.
3. Pongprasobchai S, Jianjaroonwong V, Charatcharoenwitthaya P, et al. Erythrocyte sedimentation rate and C-reactive protein for the prediction of severity of acute pancreatitis. Pancreas. 2010; 39(8): 1226-1230.doi: : 10.1097/MPA.0b013e3181deb33e
4. Prachayakul V, Aswakul P, Kachinthorn U. Spraying N-butyl-2-cyanoacrylate (Histoacryl) as a rescue therapy for gastrointestinal malignant tumor bleeding after failed conventional therapy. Endoscopy. 2011; 43(Suppl 2): E227-E228. doi: 10.1055/s-0030-1256350
5. Prachayakul V, Aswakul P, Kachinthorn U. Tapered-tip Teflon catheter: another device for sequential dilation in endoscopic ultrasound-guided hepaticogastrostomy. Endoscopy. 2011; 43(Suppl 2): E213-E214. doi: 10.1055/s-0030-1256395
6. Prachayakul V, Aswakul P, Kachintorn U. Bleeding hepaticojejunostomy anastomotic varices successfully treated with Histoacryl injection, using single-balloon enteroscopy. Endoscopy. 2011; 43(Suppl 2): E153. doi: 10.1055/s-0030-1256233
7. Prachayakul V, Aswakul P, Kachintorn U. EUS-guided choledochoduodenostomy for biliary drainage using tapered-tip plastic stent with multiple fangs. Endoscopy. 2011; 43(Suppl 2): E109-E110. doi: 10.1055/s-0030-1256140.
8. Prachayakul V, Aswakul P, Kachintorn U. Atypical clinical presentation of typical endoscopic finding of Bouverets syndrome. Endoscopy. 2011; 43(Suppl 2): E55-E56. doi: 10.1055/s-0030-1256059
9. Prachayakul V, Aswakul P, Kachintorn U. Common bile duct stone removal with overtube-assisted direct peroral cholangioscopy, without balloon inflation, using an ultra-slim gastroscope following electrohydraulic lithotripsy. Endoscopy. 2011; 43(Suppl 2): E273-E274. doi: 10.1055/s-0030-1256351
10. Prachayakul V, Aswakul P, Kachintorn U. Overtube-assiste direct peroral pancreatoscopy using an ultraslim gastroscope in a patient suspected of having and intraductal papillary mucinous neoplasm. Endoscopy. 2011; 43(Suppl 2): E279-E280. doi: 10.1055/s-0030-1256351
11. Prachayakul V, Aswakul P, Kachintorn U. Complete obstructive esophageal cancer with esophagopleural fistula successfully treated by combined antegrade and retrograde rendezvous technique. Endoscopy. 2011; 43(Suppl 2): E354-E355. doi: 10.1055/s-0030-1256858
12. Prachayakul V, Aswakul P, Limsrivilai J, et al. Benefit of “transparent soft-short-hood on the scope” for colonoscopy among experienced gastroenterologists and gastroenterologist trainee: a randomized, controlled trial. Surg Endosc. 2012; 26(4): 1041-1046. doi: 10.1007/s00464-011-1992-7
13. Prachayakul V, Aswakul P, Kachintorn U. Incidental removal of distal common bile duct adenoma after plastic stent placement. Endoscopy. 2012; 44(Suppl 2): E11-E12. doi: 10.1055/s-0031-1291497
14. Prachayakul V, Aswakul P, Kachintorn U. Duodenal perforation due to plastic stent migration successfully treated by endoscopy. Gastrointest Endosc. 2012; 75(6): 1265-1266. doi: 10.1016/j.gie.2012.01.036
15. Prachayakul V, Aswakul P, Kachintorn U. EUS guided fine needle aspiration cytology of liver nodules suspicious for malignancy: yields, complications and impact on management. J Med Assoc Thai. 2012; 95(Suppl 2): S56-S60.
16. Prachayakul V, Aswakul P, Pongprasobchai S, et al. Clinical characteristics, endosonographic findings and etiologies of gastroduodenal subepithelial lesions: a Thai referral single center study. J Med Assoc Thai. 2012; 95(Suppl 2): S61-S67.
17. Prachayakul V, Sriprayoon T, Asawakul P, Pongprasobchai S, Pausawasdi N, Kachintorn U. Repeated endoscopic ultrasound guided fine needle aspiration (EUS-FNA) improved diagnostic yield of inconclusive initial cytology for suspected pancreatic cancer and unknown intra-abdominal lymphadenopathy. J Med Assoc Thai. 2012; 95(Suppl 2): S68-S74.
18. Prachayakul V, Aswakul P, Apisarnthanarak P, Pongprasobchai S. Diffuse type autoimmune pancreatitis: the first case report in Thailand. J Med Assoc Thai. 2012; 95(Suppl 2): S261-4.
19. Aswakul P, Prachayakul V, Lohsiriwa V, Bunyaarunnate T, Kachintorn U. Screening colonoscopy from a large single center of Thailand-something needs to be changed? Asian Pac J Cancer Prev. 2012; 13(4): 1361-1364.
20. Prachayakul V, Aswakul P, Leelakusolvong S. Endoscopic ultrasound-guided transgastric biliary metal stent placement after dukatuib with tapered-tip Tefkib catgeters abd marking with a clip. Endoscopy. 2012; 44(Suppl 2): E329-E330. doi: 10.1055/s-0032-1309857
21. Prachayakul V, Aswakul P. Successful endoscopic treatment of iatrogenic biloma as a complication of endosonography giuded hepaticogastrostomy: The first case report. J Interv Gastroenterol. 2012; 2: 202-204.
22. Phisalprapa P, Prachayakul V. Ascariasis as an unexpected cause of acute pancreatitis with cholangitis: a rare case report from urban area. JOP. 2013; 14(1): 88-91. doi: 10.6092/1590-8577/1257.
23. Prachayakul V, Aswakul P, Deesomsak M, Pongpaibul A. Gastric pancreatic heterotopia: an unusual cause of upper gastrointestinal bleeding. Endoscopy. 2013; 45(Suppl 2): E7-E8. doi: 10.1055/s-0032-1326120
24. Prachayakul V, Aswakul P, Leelakusolvong S. Massive gastric antral vascular ectasia successfully treated by endoscopic band ligation as the initial therapy. World J Gastrointest Endosc. 2013; 5(3): 135-137. doi: 10.4253/wjge.v5.i3.135
25. Prachayakul V, Chaisayan S, Aswakul P, Deesomsak M. Clinical characteristics and treatment outcomes of patients with unresectable cholangiocatrcinoma in Thailand: are there differences dependent on stent type? Asian Pac J Cancer Prev. 2013; 14(1): 529-532.
26. Sirimontaporn N, Aswakul P, Junyangdikul P, Prachayakul V. Early neoplasia of the common bile duct diagnosed and completely removed using multiple endoscopic modalities. Endoscopy. 2013; 45(Suppl 2): E102-E103. doi: 10.1055/s-0032-1326278.
27. Prachayakul V, Aswakul P, Deesomsak M, pongpaibul A. Multifocal plasmacytoma presenting with upper gastrointestinal bleeding, chronic diarrhea, and multiple sites of small-bowel intussusception. Endoscopy. 2013; 45(Suppl 2): E84-E85. doi: 10.1055/s-0032-1326262
28. Pongprasobchai S, Lertwattanarak R, Pausawasdi N, Prachayakul V. Diagnosis and localization of insulinoma in Thai patients: performance of endoscopic ultrasonography compared to computed tomography and magnetic resonance imaging. J Med Assoc Thai. 2013; 96(Suppl 2): S187-S193.
29. Aswakul P, Prachayakul V. Tropical sprue: two cases report and review of literature. Has anything changed in the past 40 years? J Med Assoc Thai. 2013; 96(Suppl 2): S266-S269.
30. Prachayakul V, Aswakul P. Successful endoscopic treatment of iatrogenic biloma as a complication of endosonography guided hepaticogastrostomy: The first case report. J Interv Gastroenterol. 2012; 2(4): 202-204.
31. Prachayakul V, Aswakul P, Chantarojanasiri T, Leelakusolvong S. Factors influencing clinical outcomes of Histoacryl(R) glue injection-treated gastric variceal hemorrhage. World J Gastroenterol. 2013; 19(15): 2379-2387.doi: 10.3748/wjg.v19.i15.2379.
32. Prachayakul V, Aswakul P. Failure of sequential biliary stenting for unsuccessful common bile duct stone removal. World J Gastrointest Endosc. 2013; 5(6): 288-292. doi: 10.4253/wjge.v5.i6.288.
33. Prachayakul V, Deesomsak M, Aswakul P, Leelakusolvong S. The utility of single-balloon enteroscopy for the diagnosis and management of small bowel disorders according to their clinical manifestations: a retrospective review. BMC Gastroenterol. 2013; 13(1): 1-7. doi: 10.1186/1471-230X-13-103
34. Aswakul P, Janyangdikul P, Prachayakul V. Thickened esophagus as an unusual manifestation of eosinophilic esophagitis. Dis Esophagus. 2013. doi: 10.1111/dote.12044
35. Prachayakul V, Aswakul P. A novel technique for endoscopic ultrasound-guided biliary drainage. World J Gastroenterol. 2013; 19(29): 4758-4763. doi: 10.3748/wjg.v19.i29.4758.
36. Prachayakul V, Thamtorawat S, Siripipattanamongkol C, Thanathanee P. Bleeding left hepatic artery pseudoaneurysm: a complication of endoscopic ultrasound-guided hepaticogastrostomy. Endoscopy. 2013; 45 (Suppl 2): E223-E224. doi: 10.1055/s-0033-1344064
37. Prachayakul V, Aswakul P, Deesomsak M, Pongpaibul A. Gastric somatostatinoma: an extremely rare cause of upper gastrointestinal bleeding. Clin Endosc. 2013; 46(5): 582-585. doi: 10.5946/ce.2013.46.5.582
38. Prachayakul V, Aswakul P. Tapered-tip catheter dilatation: a safe technique for EUS-guided transesophageal drainage of peripancreatic fluid collections. J Interv Gastroenterol. 2013; 3(1): 31-33.
39. Prachayakul V, Aswakul P, Kachintorn U. Electrohydraulic lithotripsy as an highly effective method for complete large common bile duct stone clearance. J Interv Gastroenterol. 2013; 3(2): 59-63.
40. Prachayakul V, Phisalprapa P, Aswakul P. Infected Walled-Off Pancreatic Necrosis following EUS-Guided Drainage Successfully Treated Using Multiple Stents in Different Sites Technique. Case Rep Gastroenterol. 2013; 7(3): 404-408. doi: 10.1159/000355347
41. Deesomsak M, Aswakul P, Junyangdikul P, Prachayakul V. Rare adult gastric duplication cyst mimicking a gastrointestinal stromal tumor. World J Gastroenterol. 2013; 19(45): 8445-8448. doi: 10.3748/wjg.v19.i45.8445
42. Prachayakul V. Current Status of Endoscopic Treatment of Advanced Hilar Cholangiocarcinoma. J Gastroint Dig Syst. 2014; 4: 168. doi: 10.4172/2161-069X.1000168
43. Deesomsak M, Sawanyawisuth K, Prachayakul V. An unusual cause of chronic diarrhoea. Trop Biomed. 2014; 31(1): 187-189.
44. Prachayakul V, Aswakul P, Bhunthumkomol P, Deesomsak M. Diagnostic yield of endoscopic ultrasonography in patients with intermediate or high likelihood of choledocholithiasis: a retrospective study from one university-based endoscopy center. BMC Gastroenterol. 2014; 14: 165. doi: 10.1186/1471-230X-14-165