guo hou loo, farhana raduan, zunaidah abu samah and nik ritza kosai .  (2026).  prevalence and longitudinal development of sarcopenic obesity in an asian obese population: a large bioelectrical impedance analysis study.  - frontiers in nutrition.  1 - 8. 

su teng lau, guo hou loo, shue hong kong, norlaila mustafa, nik ritza kosai.  (2026).  metabolic bariatric surgery versus medical therapy for type 2 diabetes: a 5-year real-world cost and remission analysis.  - obesity surgery.  3777 - 3784. 

wei lun tan, guo hou loo, guhan muthkumaran, nik ritza kosai.  (2026).  long-term weight loss and metabolic outcomes after bariatric surgery in a large asian cohort: a real-world cohort study.  - obesity surgery.  3736 - 3744. 

guo hou loo, meng xian chan, zhun shen tan and nik ritza kosai.  (2026).  giant paraumbilical hernia causing gastric outlet obstruction in a young man with class iii obesity: a case report and literature review.  - frontiers in surgery.  1 - 11. 

jo ann andoy galvan, guo hou loo, nik ritza kosai, chai hong yeong, karuthan chinna, rusli nordin, kenneth kwing-chin lee, norlaila mustafa.  (2026).  long-term clinical outcomes and cost-effectiveness of bariatric surgery for type 2 diabetes in malaysia: a 10-year retrospective cohort study.  - journal of multidisciplinary healthcare.  1 - 12. 

guo hou loo, nik aisyah kosai, val michael villareal, guhan muthukumaran and nik ritza nik mahmood .  (2026).  case report: three contrasting presentations of acute oesophageal necrosis and the determinants of outcome.  - frontiers in medicine.  1 - 11. 

natasia nicole deser, hans alexander mahendran, guo hou loo and nik ritza kosai.  (2026).  prehabilitative parenteral nutrition and surgery-related muscle loss in patients undergoing major upper gastrointestinal surgery: a single-centre observational cohort study.  - frontiers in nutrition.  1 - 10. 

theeran kaur gill, guo hou loo, guhan muthkumaran, nik ritza kosai.  (2025).  posterior membranous tracheal injury during mckeown oesophagectomy. a case report with literature review..  - frontiers in oncology.  1 - 6. 

mardiana mardan, wei keat ooi, arif hameed sultan, guo hou loo, nik ritza kosai.  (2025).  delayed strangulated hiatal hernia post-gastrectomy masquerading as diaphragmatic hernia: a diagnostic pitfall.  - cureus .  1 - 9. 

solomon raj vasudayan, guo hou loo, mogaraj sellapan, geok chin tan, nik ritza kosai.  (2025).  small bowel volvulus secondary to meckel’s diverticulum with meso-diverticular band: a case report and literature review.  - cureus.  1 - 5. 

muhamad zulhilmi akmal zainuddin, jemaima che hamzah, nik ritza kosai nik mahmood, cheng teck chee, mae-lynn catherine bastion.  (2025).  nutritional optic neuropathy: bariatric surgery gone wrong.  - cureus.  1 - 12. 

wan izzah wan jaffar, guo hou loo, fazarina mohammed, deborah chia hsin chew, guhan muthkumaran and nik ritza kosai.  (2025).  case report: rare case of signet ring gastric adenocarcinoma with rectal metastasis.  - frontiers in oncology.  1 - 6. 

firdaus che ani, guo hou loo, richelle huey bing chua, kok-yong chin, nik ritza kosai.  (2025).  integrating cruroplasty with laparoscopic sleeve gastrectomy: a strategy to mitigate gerd symptoms in obese patients. a randomized control trial.  - langenbeck's archives of surgery.  1 - 7. 

richelle huey bing chua, guo hou loo, nani hl, guhan muthkumaran, nik ritza kosai.  (2025).  bariatric surgery as an adjunctive treatment for failed back surgery syndrome: a case report highlighting a multidisciplinary approach.  - cureus.  1 - 6. 

solomon raj vasudayan, guo hou loo, guhan muthkumaran, nik ritza kosai .  (2025).  gastric perforation secondary to a hyperinflated intragastric balloon: a case report and management approach.  - cureus.  1 - 7. 

mang ning ong, guo hou loo, guhan muthkumaran, suria hayati md pauzi, nik ritza kosai.  (2024).  incarcerated incisional hernia: an unusual presentation of metastatic endometrial carcinoma.  - cureus.  1 - 9. 

amrit manik nasta, ramen goel, rishi singhal, luc lemmens, sarfaraz baig, yosuke seki, arun prasad, sonja chiappetta, mohammad kermansaravi, marc vertruyen, beniamino pascotto, juan santiago azagra, waleed al-khyatt, gennaro martines, diva y villao, leandro revello, marco rioseco, francesco martini, arnaud liagre, gildas juglard, giovanni dapri, monika a proczko-stepaniak, adel k abou-mrad, hosam m elghadban, christine stier, jasper l van herck, safwan abdulrahman taha, ozan sen, bruno dillemans, stijn van hoef, mathieu vandeputte, sofie viskens, paolo gentileschi, raj palaniappan, nasser sakran, thomas h shin, ali aminian, matteo uccelli, stefano olmi, giovanni c cesana, marco anselmino, nicolas p a debergh, daniel gärtner, wah yang, digvijay s bedi, kamal mahawar, haidar abdalah, hytham hamid, rajesh gianchandani-moorjani, vincenzo bottino, alfonso bosco, errichetta napolitano, ravikrishna mamidanna, brij madhok, débora acín-gándara, manuel medina-garcía, sajith kumar, rajneesh bankenahally, yasmin sarfaraz, heather fry, tom wiggins, krishnamohan yarlagadda, anna popp, tadeja pintar, francesk mulita, georgios-ioannis verras, michail vailas, george skroubis, manish khaitan, giovanni lezoche, urs pfefferkorn, shahab shahabi, amir davarpanah, cunchuan wang, zhiyong dong, amador garcia ruiz de gordejuela, ramón vilallonga, Óscar gonzález, piotr major, piotr zarzycki, justyna rymarowicz, yannick nijs, jaydeep palep, randeep wadhawan, deepa kizhakke veetil, carlos esquivel, manuel garcía, fernando martinez lascano, maría muriel, josé foscarini, fajer nassour, kazunori kasama, agustin duro, sang hyun kim, aatif inam, sharad sharma, radwan kassir, manuel aceves avalos, saeed alsareii, miljana vladimirov, michela campanelli, domenico benavoli, emanuela bianciardi, juan carlos sebastián-tomás, ramón trullenque-juan, josé Ángel díez-ares, octávio viveiros, rui ribeiro, muzaffer al, ahmet gökhan, nikhilesh krishna, bassel haj, ramy gfely, jabra arraf, abdallah omari, ali awad, pranoy gupt, jacques himpens, jonathan super, vasileios charalampakis, markos daskalakis, mohamed sahloul, spyridon kapoulas, arab rawashdeh, kareem sillah, govindan raghuraman, ana garcia navarro, nr kosai, mohd firdaus che ani.  (2024).  30-day morbidity and mortality of revisional bariatric surgery – an international multi-centre collaborative (broad) study.  - obesity research & clinical practice.  195 - 200. 

farah marzuki, loo guo hou, nik farhan nik fuad, nik ritza kosai.  (2024).  haemorrhagic shock after iatrogenic deep circumflex iliac artery injury during paracentesis: a rare lethal complication.  - cureus.  1-5. 

loo guo hou, guhan muthkumaran, nik ritza kosai.  (2024).  unusual presentation of incarcerated true parahiatal hernia: management of a rare clinical entity.  - cureus.  1-6. 

wei soon pang, guo hou loo, guo jeng tan, mardiana mardan, reynu rajan, & nik ritza kosai.  (2024).  comparative evaluation of early diabetic outcomes in southeast asian patients with type 2 diabetes mellitus undergoing roux-en-y gastric bypass (rygb) verssus sleeve gastrectomy (lsg).  - scientific reports.  1-7. 

jun sen chuah, jih huei tan, mohamad adam bujang, koon khee chan, nik ritza kosai.  (2024).  transcutaneous electric nerve stimulation of acupuncture points improves tolerance in adults undergoing diagnostic upper gastrointestinal endoscopy - a single center, double-blinded, randomized controlled trial.  - surgical endoscopy.  3279 - 3287. 

nik ritza kosai, aishath azna ali, ryan ghita, guhan muthkumaran, ismail ali, guo hou loo, firdaus hayati.  (2024).  one-year outcomes in a supervised program of swallowable intragastric balloon—analysis of 486 patients in a high-volume bariatric centre in malaysia.  - obesity surgery.  3366 - 3371. 

asif sukri, alfizah hanafiah, nik ritza kossai, mohamad aznan shuhaili, mustafa mohammed taher, raja affendi raja ali.  (2024).  perbandingan pengekspresan antigen kluster pembezaan dalam subjenis tumor dan darah periferi pesakit kanser gaster .  - sains malaysiana.  3253 - 3262. 

rajdave singh sadu singh, guo hou loo, guhan muthkumaran, aishath azna ali, nik ritza kosai.  (2024).  reversal of roux-en-y gastric bypass to normal anatomy in a severely malnourished patient after metabolic bariatric surgery.  - cureus.  1 - 5. 

loo guo hoo, nadia nafsha baharudin, mohamed arif hameed sultan, reynu rajan, nik ritza kosai, lizawati rasul hamidi.  (2023).  adult idiopathic hypertrophic pyloric stenosis presenting with gastroduodenal intussusception: a rare case report.  - turkish journal of surgery.  377-382. 

alfizah hanafiah, asif sukri, nik ritza kosai, mohamad aznan shuhaili, mustafa mohammed taher & raja affendi raja ali.  (2023).  immunophenotyping of gastritis, gastric ulcer and gastric cancer using a cluster of differentiation (cd) antibody microarray.  - sains malaysiana.  187-197. 

mohamed arif hameed sultan, muhamad hud muhamad zin, firdaus hayati, zulkifli md zainuddin, nik ritza kosai, reynu rajan, zainal adwin zainal abidin, dayang corieza febriany.  (2023).  improvement in erectile dysfunction among male obese patient, following bariatric surgery in hospital canselor tuanku muhriz (hukm).  - obesity surgery.  1506-1518. 

mohamed arif hameed sultan, nik ritza kosai, reynu rajan, mustafa taher, aznan shuhaili, dayang corieza febriany.  (2023).  malignant melanoma of oesophagus: a rare entity.  - gazi medical journal.  82-85. 

david eng yeow gan, nik ritza kosai nik mahmood, jitt aun chuah, firdaus hayati.  (2023).  performance and diagnostic accuracy of scoring systems in adult patients with suspected appendicitis.  - lagenbeck's archives of surgery.  1-9. 

global surgery, globalsurg collaborative, mustafa mohammed taher, nik ritza kosai, dayang nita abdul aziz, reynu rajan.  (2023).  use of telemedicine for postdischarge assessment of the surgical wound: international cohort study, and systematic review with meta-analysis.  - annals of surgery.  1331-1347. 

nur izreena ismail, khairul najmi muhammad nawawi, deborah chew chia hsin, kok wei hao, nik ritza kosai nik mahmood, gary lee chong chearn, zhiqin wong, azmi mohd tamil, hazel joseph, raja affendi raja ali.  (2023).  probiotic containing lactobacillus reuteri dsm 17648 as an adjunct treatment for helicobacter pylori infection: a randomized, double- blind, placebo- controlled trial.  - helicobacter.  1-11. 

lee qz, nik ritza k, mohd firdaus ca, muhammad m.  (2023).  the impact of laparoscopic intraperitoneal instillation of ropivacaine in enhancing respiratory recovery and reducing acute postoperative pain in laparoscopic sleeve gastrectomy: a double-blinded randomised control; relieve trial.  - obesity surgery.  3141-3146. 

mohd haidir roslan, mohd asyiq raffali, shawal faizal mohamad, nik ritza kosai nik mahmood, hamat hamdi che hassan.  (2023).  cardiac and metabolic effects of bariatric surgery among obese patients in a malaysian tertiary hospital: a 6-month prospective cohort study.  - journal of the asean federation of endocrine societies.  1-7. 

wah-kheong chan, soek-siam tan, siew-pheng chan, yeong-yeh lee, hoi-poh tee, sanjiv m., khean-lee goh, anis safura ramli, feisul m., nik ritza k. dan raja affendi ra.  (2022).  malaysian society of gastroenterology and hepatology consensus statement on metabolic dysfunction-associated fatty liver disease.  - gastroenterology and hepatology.  795-811. 

nik ritza kosai, raja affendi raja ali.  (2022).  global multi-stakeholder endorsement of the mafld definition.  - the lancet gastroenterology and hepatology.  388-390. 

masayuki o, soo min a, yosuke s, wah y, simon kin hw, suthep u, jefrey m. h, manish k, nik ritza k, weu w, june l, reno r, thejana w, edward o.  (2022).  ten years of change in bariatric/metabolic surgery in the asia-pacific region with covid-19 pandemic: ifso-apc national reports 2021.  - obesity surgery.  2994-3004. 

asif sukri, alfizah hanafiah, nik ritza kosai, mustafa mohammed taher, ramelah mohamed.  (2022).  new insight on the role of helicobacter pylori caga in the expression of cell surface antigens with important biological functions in gastric carcinogenesis.  - helicobacter.  1-8. 

raymond zml, hans am, malaysian upper gastrointestinal surgical society (mugis), ng cb, low ky, sekkapan t, ngo cw, nik ritza kosai, reynu r, mohamad as, ahmad sudiman ms, ramesh g, azrina ab, mahadevan dt, vijaya sa, wan najmi wd, lim sy, kelvin v, moha.  (2022).  esophageal squamous cell carcinoma and adenocarcinoma in malaysia - pooled data from upper gastrointestinal centers in a multiethnic asian population.  - cancer epidemiology.  1-8. 

asif sukri, alfizah hanafiah, and nik ritza kosai.  (2022).  the roles of immune cells in gastric cancer: anti-cancer or pro-cancer?.  - cancers.  1-14. 

nur izreena ismail, raja affendi raja ali, zhiqin wong, khairul najmi muhammad nawawi, wei hao kok, nik ritza kosai nik mahmood, chia hsin chew, chong chearn lee, azmi mohd tamil, hazel joseph.  (2022).  the effect of lactobacillus reuteri probiotic as an adjunct treatment for helicobacter pylori infection in adults.  - gut.  1. 

syarifah nafisah al-yahya, muhammad haffiz haslam mohamed akram, kasturi vijaya kumar, siti nor asyrah mat amin, noor alifah abdul malik, nor ain mohd zawawi, nik ritza kosai nik mahmood,norlaila mustafa, mawaddah azman, and marina mat baki.  (2022).  maximum phonation time normative values among malaysians and its relation to body mass index.  - journal of voice.  457-463. 

abdul gafoor am, reynu r, kirubakaran m, vimal kv, nik ritza kosai nm, tikfu g, haron a.  (2021).  patient and procedure selection for bariatric and metabolic surgery in malaysia- the malaysian consensus.  - medical journal of malaysia.  229-232. 

zahra rashidbenam, mohd hafidzul jasman, guan hee tan, eng hong goh, xeng inn fam, christopher chee kong ho, zulkifli md zainuddin, reynu rajan, rizal abdul rani, fatimah mohd nor, mohamad aznan shuhaili, nik ritza kosai, farrah hani imran, min hwei ng.  (2021).  fabrication of adipose-derived stem cell-based self-assembled scaffold under hypoxia and mechanical stimulation for urethral tissue engineering.  - international journal of molecular sciences.  1-32. 

kavitha subramanian, low wy, lau pc, chin kf, chinna k, nik ritza kosai, mustafa taher, reynu r.  (2021).  changes in eating behaviours following bariatric surgery: a prospective study.  - journal of experimental biology and agricultural sciences.  101-109. 

ahmad adib bin mohd nasir, andrea yu-lin ban, syed zulkifli syed zakaria, nik ritza kosai nik mahmood and mohamed faisal abdul hamid.  (2021).  a single tertiary centre outlook on the short-term outcome of bariatric surgery in improving pulmonary parameters and sleep apnoea.  - proceedings of singapore healthcare.  91-98. 

mawaddah azman, ng sze yin, abdullah sani mohamed, marina mat baki, mustafa mohammed taher, nik ritza kosai.  (2021).  surgical versus conventional weight loss therapy for obstructive sleep apnea, a randomized controlled trial: quantitative and qualitative outcome.  - medical journal of malaysia.  23. 

dalilah diyana alfian sulai, theevashini k, nik ritza kosai nik mahmood.  (2021).  diagnostic challenge in silent metastatic invasive breast carcinoma: dysphagia as the only symptom.  - bmj case report.  1-3. 

muhamad hud muhamad zin, theevashini krishnasamy, nik ritza kosai.  (2021).  retro umbilical abscess mimicking infected urachal cyst: a rare presentation from migratory fish bone ingestion.  - gazi medical journal.  466-468. 

reynu rajan, mohammed sam-aan, nik ritza kosai, mohamad aznan shuhaili, tee sze chee, ajay venkateswaran, kamal mahawar.  (2020).  early outcome of bariatric surgery for the treatment of type 2 diabetes mellitus in super-obese malaysian population.  - journal of minimal access surgery.  47-53. 

asif sukri, alfizah hanafiah, noraziah mohamad zin, nik ritza kosai.  (2020).  epidemiology and role of helicobacter pylori virulence factors in gastric cancer carcinogenesis.  - apmis.  150-161. 

jimmy bys, jiafu j, sang uk, masanori t, guoxin li, hh kim, simon l, asim s, kyo ys, woo jh, nik ritza kosai, koji k, kazunari m, hiroshi y, takahiro k, peng cl, young wk, jaideeraj r, bee ct, hk yang, expel study group.  (2020).  extensive peritoneal lavage after curative gastrectomy for gastric cancer study (expel): an international multicenter randomized controlled trial.  - journal of clinical oncology.  279. 

loo guo hou, reynu rajan, azmi mohd tamil, nik ritza kosai.  (2020).  prevalence of obstructive sleep apnea in asian bariatric population: an underdiagnosed dilemma.  - surgery for obesity and related disease.  778-783. 

pei pei lee,theevashini krishnasamy, mustafa taher, nik ritza kosai nik mahmood.  (2020).  partially eroded gastric band after 13 years - endoscopic removal with emergency lithotripter device.  - surgical chronicles.  44-46. 

loo guo hoo, reynu rajan, mahadevan deva tata, nik ritza kosai.  (2020).  changes in the disease-specific quality of life following dor fundoplication. a multicentre cross-sectional study.  - annals of medicine and surgery.  252-255. 

sivesh kk., sheraz rm., pritam s., ewan ag., on behalf of oeasophagogastric anastomosis audit group.  (2020).  the influence of the sars-cov-2 pandemic on esophagogastric cancer services: an international survey of esophagogastric surgeons.  - diseases of the esophagus.  1-12. 

surita binti said, guo hou loo, nik ritza kosai, reynu rajan, rozita mohd, asrul abdul wahab, shamsul azhar shah.  (2020).  reduction in urinary chemokine (c-c motif) ligand 2 (ccl-2) after surgery-induced weight loss.  - scientific reports.  1-6. 

globalsurg collaborative; dayang nita abdul aziz, reynu rajan, mohammed taher, nik ritza kosai.  (2019).  pooled analysis of who surgical safety checklist use and mortality after emergency laparotomy.  - british journal of surgery.  103-112. 

sivaneswaran lechmiannandan, mayurran panirselvam, prema muninathan, narwani hussin, reynu rajan, hatta sidi, nik ritza kosai & c. rajkumar vinayak.  (2019).  resolution of female sexual dysfunction (fsd) among the obese multiethnic malaysian women now a reality with bariatric surgery: a prospective pilot study in malaysia.  - obesity surgery.  1571-1575. 

asif sukri, alfizah hanafiah, nik ritza kosai, mustafa mohamed taher, isa mohamed rose & ramelah mohamed.  (2019).  optimization of cryopreserved single cell suspension of gastric epithelial cells for successful dotscantm antibody microarray.  - sains malaysiana.  1105-1110. 

lai jun hai, loo guo hou, mohamad aznan shuhaili, nik ritza kosai.  (2019).  a novel alternative to suture passer for closure of fascial defect in laparoscopic ventral hernia repair: a case report.  - international journal of surgery case reports.  276-280. 

diana mellisa dualim, loo guo hou, reynu rajan. nik ritza kosai nik mahmood.  (2019).  jejunal gist: hunting down an unusual cause of gastrointestinal bleed using double balloon enteroscopy. a case report.  - international journal of surgery case report.  303-306. 

loo gou hou, reynu rajan, nik ritza kosai nik mahmood.  (2019).  staple-line post primary sleeve gastrectomy. a two patient case series and literature review.  - annals of medicine and surgery.  72-76. 

nadiah rosly, loo guo hou, mohamad aznan shuhaili, reynu rajan, nik ritza kosai.  (2019).  oesophageal perforation following transoesophageal echocardiography: a case report on successful conservative management.  - international journal of surgery case reports.  161-164. 

loo guo hou, anusha prabakaran, reynu rajan, fatimah binti mohd nor, nik ritza kosai.  (2019).  concurrent bariatric surgery and surgical resection of massive localized lymphedema of the thigh. a case report..  - annals of medicine and surgery.  53-56. 

zahra rashidbenam, mohd hafidzul jasman, pezhman hafez, guan hee tan, eng hong goh, xeng inn fam, christopher chee kong ho, zulkifli md zainuddin, reynu rajan, fatimah mohd nor,mohamad aznan shuhaili, nik ritza kosai, farrah hani imran, min hwei ng.  (2019).  overview of urethral reconstruction by tissue engineering: current strategies, clinical status and future direction.  - tissue engineering and regenerative medicine.  365-384. 

fatin hanani mazri, suzana shahar, nik ritza kosai, mohd azahadi omar, nilsiswati ramilis & reynu rajan.  (2019).  a retrospective study of weight-loss predictors following bariatric surgery in malaysian patients with obesity.  - malaysian journal of nutrition.  423-433. 

juhanis fj, reynu r, mustafa mt, mohd aznan s, iman g, nik ritza k.  (2019).  internal hernia after roux en y gastric bypass: a paradigm shift of practice.  - surgical chronicles.  140-143. 

amir am, iman g, mustafa mt, nik ritza k.  (2019).  ebv-positive gastric carcinoma with lymphoid stroma: a novel variant gastric neoplasm predicting good patient's prognosis.  - surgical chronicles.  82-84. 

mustafa mohammed taher, nik ritza kosai, dayang nita abdul aziz, reynu rajan.  (2018).  surgical site infection after gastrointestinal surgery in high-income, middle-income and low-income countries: a prospective, international, multicentre cohort study.  - lancet infectious disease.  . 

reynu rajan, nik ritza kosai.  (2018).  history and progress of bariatric surgery in malaysia.  - obesity surgery.  . 

chik ian, razman jarmin, affirul ariffin, hairol othman, zamri zuhdi, azlanudin azman, nik ritza kosai nik.  (2018).  a less invasive method of reducing the incidence of post-endoscopic retrograde cholangiopancreatography pancreatitis: intravenous diclofenac sodium versus placebo.  - asian journal of pharmaceutical and clinical research.  140-144. 

gendeh hs, taher mm, kosai nr, bs gendeh, muhammad ramzisham ar, das s.  (2018).  early buried bumper syndrome: bump it before you get buried.  - surgical chronicles.  . 

kavitha subramaniam, wah-yun low, peng-choong lau, kin-fah chin, karuthan chinna, nik ritza kosai, mustafa mohammed taher, and reynu rajan.  (2018).  eating behaviour predicts weight loss six months after bariatric surgery: a longitudinal study.  - nutrients.  1-13. 

globalsurg collaborative, dayang nita abdul aziz, mustafa mohamed, reynu rajan, nik ritza kosai..  (2018).  management and outcomes following surgery for gastrointestinal typhoid: an international, prospective, multicentre cohort study.  - world journal of surgery.  . 

hui ying khoo, kelvin voon, keat how teoh, shyang yee lim, premnath nagalingam, mohamad aznan shuhaili, reynu rajan, mustafa mohammed taher, nik ritza kosai.  (2018).  esophageal cancer in malaysia: the need for early detection.  - disease of the esophagus.  . 

globalsurg collaborative, nik ritza kosai, mustafa taher, reynu rajan.  (2018).  laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.  - surgical endoscopy.  . 

muhammad adi syazni, hardip singh gendeh, nik ritza kosai, mohd ramzisham abdul rahman, balwant singh gendeh, normala basiron, farrah hani imran.  (2017).  follicular thyroid cancer with sternal metastasis-challenges and outcomes.  - medical journal of malaysia.  80-82. 

nik kosai , anitha haniffa, razman jarmin, srijit das, reynu rajan, hanafiah harunarashid.  (2017).  paget-schroetter syndrome in 52-year-old male:an interesting case report.  - journal of krishna institute of medical sciences university.  104-106. 

ng chong beng, nik ritza kosai, lim shyang yee, srijit das, subasri a, reynu rajan.  (2017).  perianal ulcer and diabetes insipidus : a rare presentation of langerhans cell histiocytosis in an adult male.  - online journal of health and allied science.  1-3. 

zar chi thent, chiranjib chakraborty, pasuk mahakkanukrauh, nik ritza kosai nik mahmood, reynu rajan and srijit das.  (2017).  the molecular concept of atheromatous plaques.  - current drug targets.  1250-1258. 

ngo choon woon, nik ritza kosai, razman jarmin, mohd aznan shuhaili, mustafa mohd taher , reynu rajan.  (2017).  double trouble: cocurrent sigmoid volvulus and gastric volvulus in alzheimer`s disease.  - online journal of health and allied sciences.  . 

asif sukri, alfizah hanafiah, nik ritza kosai, mustafa mohamed taher and isa mohamed rose.  (2017).  distribution of gastric adenocarcinoma subtypes in different ethnicities in kuala lumpur, malaysia.  - malaysian journal of pathology.  235-242. 

w. liew, y. y. wai, n. r. kosai, h. s. gendeh.  (2017).  tackers versus glue mesh fixation: an objective assessment of postoperative acute and chronic pain using inflammatory markers.  - hernia.  549-554. 

j h lai, ms aznan, r reynu, mm taher, h firdaus, nr kosai.  (2017).  non-umbilical metastasis of a pancreatic adenocarcinoma: case report and review of literature.  - surgical chronicles.  . 

mohammed hamad, reynu rajan, nik kosai, paul suttol, srijit das, hanafiah harunarashid.  (2016).  retained fractured fragment of a central venous catheter: a minimally invasive approach to safe retrieval.  - ethiopian journal of health sciences.  85-88. 

asif sukri, alfizah hanafiah, nik ritza kosai, mustafa mohamed taher and isa mohamed rose.  (2016).  surface antigen profiling of helicobacter pylori-infected and -uninfected gastric cancer cells using antibody microarray.  - helicobacter.  417-427. 

a. bhangu, ......, nr kosai, m taher, r rajan.....globalsurg collaborative.  (2016).  mortality of emergency abdominal surgery in high-, middle- and low-income countries.  - british journal of surgery.  971-988. 

m mohd sukri, a hanafiah, n nik mahmood, mmohamed taher, i mohamed rose, r mohamed.  (2016).  distribution of cd antigens in gastric adenocarcinoma cell line infected with different caga genotypes of helicobacter pylori strains.  - helicobacter.  115-116. 

n.r kosai , r reynu ,h.s gendeh, srijit das, m. lakdawala.  (2016).  concurrent mesh repair of a morgagni and umbilical hernia during a laparoscopic sleeve gastrectomy in a morbidly obese individual.  - journal of krishna institute of medical sciences university (jkimsu).  87-92. 

mohammed m hajhammad , reynu rajan, nik ritza kosai, badrulhisham bahadzor.  (2016).  transmesenteric small bowel herniation causing intestinal obstruction following laparoscopic transperitoneal nephrectomy.  - formosan journal of surgery.  161-164. 

nik ritza kosai, hardip singh gendeh, jing liang ho, yi rong chiew, mustafa mohamed taher, paul anthony sutton.  (2016).  laparoscopic totally transhiatal diverticulectomy of giant epiphrenic oesophageal diverticulum.  - eastern journal of medicine.  141-144. 

hardip singh gendeh, bmbs, avinesh singh bhar, mbbs, manvin kaur gendeh, mbchb, hayati yaakup, mmed, balwant singh gendeh, famm, nik ritza kosai, frcs, ramzisham abdul rahman, ms.  (2016).  caring for the dying in a developing country, how prepared are we?.  - medical journal of malaysia.  259-263. 

jagwani a.v., reynu r., bin affirul a.c., mustafa m.t., kosai n.r..  (2016).  resolution of acanthosis nigricans following curative gastric carcinoma resection.  - clinica terapeutica.  99-100. 

dharmaraj b., kosai n.r., gendeh h., ramzisham a.r., das s..  (2016).  a prospective cohort study on quality of life after endoscopic thoracic sympathectomy for primary hyperhidrosis.  - clinica terapeutica.  67-71. 

reynu r, zainal za, kosai nr.  (2016).  pre-operative methods to reduce liver volume:a randomised controlled trial comparing the use of omega-3polyunsaturated fatty acid supplements vs vlcd restriction in patients awaiting bariatric surgery.  - obesity surgery.  122-123. 

reynu r, hisham ahk, kosai nr.  (2016).  concurrent minimally invasive repair of ventral hernia during laparoscopic sleeve gastrectomy : a prospective study.  - obesity surgery (ifso).  251. 

reynu r, hilal z, kosai nr.  (2016).  early effect of bariatric surgery on serum renin-aldosterone, blood pressure and weight: a prospective study in obese malaysian population.  - obesity surgery (ifso).  282-283. 

shabbir a, bc tai, lakdawala m, huang ck, praveen raj p, sby jimmy, eng a, lomanto d, cheng ak, rao j, rajan r, delko t, kosai n, k kasama, kow l, wei-jei lee.  (2016).  influence of asian ethnicity on weight loss 3 years following laparoscopic sleeve gastrectomy.  - obesity surgery (ifso).  349. 

mohd firdaus ca, reynu r, kosai nr.  (2016).  the effect of crura reinforcement on gastro-oesophageal reflux disease score following laparoscopic sleeve gastrectomy; a randomised controlled trial.  - obesity surgery (ifso).  550-551. 

elsa jr, reynu r, kosai nr.  (2016).  the effect of laparoscopic bariatric surgery on serum fibrinogen level : a prospective study in obese malaysian population.  - obesity surgery (ifso).  552-553. 

hardip singh gendeh, noor dina hashim, mohd razif mohammad yunus, balwant singh gendeh, nik ritza kosai.  (2016).  the sequelae of barium aspiration.  - anz journal of surgery.  . 

nr kosai, r reynu, at hizami, g tikfu.  (2015).  comparative study between laparoscopic sleeve gastrectomy and laparoscopic banded gastric plication in malaysia.  - obesity surgery (ifso).  324. 

r reynu, nr kosai, a haniffa.  (2015).  predicting diabetes remission following laparoscopic bariatric surgery in morbid obesity: a malaysian experience.  - obesity surgery (ifso).  323-324. 

r reynu, nr kosai, mt mustafa, lakdawala ma.  (2015).  concurrent laparoscopic mesh repair of a morgagni hernia, umbilical hernia and sleeve gastrectomy in a morbidly obese individual.  - obesity surgery (ifso).  322-323. 

nr kosai, r rajan, ej roslani, pa sutton, m mustafa, s das.  (2015).  laparoendoscopic transgastric enucleation of an awkwardly sited peri-cardial gastrointestinal stromal tumour (gist): a multi- modal approach.  - clinica terapeutica.  248-252. 

nik kosai, reynu rajan, srijit das.  (2015).  platelet changes in healthy male smokers.  - saudi medical journal.  1501. 

reynu r, zairul ma, kosai nr, levin kb, das s.  (2015).  a rare presentation of caviar appendix in an amyand`s hernia.  - brunei international medical journal.  209-213. 

nik kosai, reynu rajan, srijit das.  (2015).  knowledge and attitude of nursing personnel towards depression in general hospitals: the korean perspective.  - journal of korean medical science.  209-1210. 

kosai n, gendeh h, norfaezan a, razman j, sutton p, das s.  (2015).  prolapsing gastric polyp causing intermittent gastric outlet obstruction.  - international surgery.  1148-1152. 

lks christopher, nr kosai, r reynu, kb levin, mm taher, pa sutton, n sukor, s das.  (2015).  effect of exercise on pulmonary function test in obese malaysian patients.  - la clinica terapeutica.  105-109. 

nr kosai, h amin-tai, hs gendeh, s salleh, r reynu, mm taher, pa sutton, s das.  (2015).  pregnant and serve acute abdominal pain: a surgical diagnostic dilemma.  - la clinica terapeutica.  110-113. 

christodoulidou m, kosai nr, rajan r, hassan s, das s, sutton pa, varghese j.  (2015).  does mesh augmentation of the hiatal repair with gore bio-a® improve symptomatic outcomes in laparoscopic fundoplication?.  - international medical journal of malaysia.  43-48. 

kosai nr, levin kb, reynu r, taher mm, ali rar, palaniappan s.  (2015).  snapshot quiz 15/1 (small bowel adenocarcinoma in crohn`s disease).  - british journal of surgery.  4-15. 

divya vanoh, suzana shahar, nik ritza kosai nik mahmood.  (2015).  association between nutrient adequacy and psychosocial factors with overall rate of weight loss after bariatric surgery.  - asia pacific journal of clinical nutrition.  610-619. 

mm taher, nr kosai, gendeh hs.  (2014).  creative treatment of early buried bumper syndrome.  - annals of the royal college of surgeons.  621-622. 

r jarmin, z zuhdi, a azman, y yusoff, ac ariffin, nrn kosai, h othman, r rahim.  (2014).  early experience of the lateral approach for laparoscopic splenic preserving distal pancreatectomy.  - hpb ( journal of internation hepato-pancreatico-biliary association).  642. 

razman jarmin, zamri zuhdi, hairol othman, yussra yusoff, affirul chairil ariffin, razrim rahim, azlanuddin azman, nik ritza nik kosai.  (2014).  the management of acute cholecystitis in pregnancy.  - hpb journal.  340. 

r.f. jailani, n.r. kosai, n.y. yaacob, r. jarmin, p. sutton, h. harunarrashid, j. murie, s. das.  (2014).  transarterial angioembolization versus surgery after failed endoscopic therapy for non-variceal upper gastrointestinal bleeding.  - la clinica terapeutica.  243-247. 

yin-ping wong, fazarina mohammed, nik ritza kosai, mustafa mohammed taher, nurismah md isa.  (2014).  a case of thyroid transcription factor-1 (ttf-1) positive primaryn euroendocrine carcinoma of oesophagus: a potential diagnostic caveat.  - malaysian journal of pathology.  86. 

nik ritza kosai, h. s. gendeh, m. noorharisman, paul anthony sutton, srijit das.  (2014).  a case of closed loop small bowel obstruction within a strangulated incisional hernia in association with an acute gastric volvulus.  - acta medica.  83-86. 

h anitha, y f lam, p a sutton, n r kosai, srijit das.  (2014).  refeeding syndrome: the danger of feeding a starving man.  - clinica terapeutica.  165(4):. 

m abdikarim, s shahari, m a idris, h hanafiah, n r kosai, s das.  (2014).  misdiagnosed infected aneurysm presenting as pyrexia of unknown origin (puo).  - clinica terapeutica.  165(4):143-145. 

thu, y; barakatun nisak, m; chin, y; gee, t; rohana, a; nik, r.  (2014).  comparison study between bariatric surgery and conventional treatment on nutritional status and quality of life among morbidly obese malaysian patients.  - obesity reviews.  15(S2):135. 

m.y. mohd rizal, n.r. kosai, p.a. sutton, z. rozman, j. razman, h. harunarashid, s. das.  (2013).  arterial embolization of a bleeding gastric dieulafoy lesion : a case report.  - clinica terapeutica.  25-27. 

yussra y, sutton pa, kosai nr, razman j, mishra rk, harunarashid h, das s.  (2013).  single incision laparoscopic surgery (sils) inguinal hernia repair - recent clinical experiences of this novel technique.  - clinica terapeutica.  425-428. 

s. farag, p sutton, k. s. leow, n. r. kosai, j razman, h. hanafiah, s. das.  (2013).  persistent mullerian duct syndrome: an interesting case report.  - la clinica terapeutica.  164(4):323-326. 

j evans, n kosai, m onwudike, h harunarashid, s das, s shahari.  (2012).  the clinical and cost effectiveness of three day limb compression with coban following surgery on varicose veins.  - international medical journal.  19(4):337-338. 

razman jarmin, azlanuddin azman, razrim rahim, nik ritza kosai and srijit das.  (2012).  a rare case of intussusception associated with metastasize small cell carcinoma of lung.  - acta medica iranica.  50(11):782-784.