Unsedated Transnasal Endoscopy for Preoperative Examination of Bariatric Patients: a Prospective Study

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Esophagogastroduodenoscopy is a preoperative examination commonly required for candidates to bariatric surgery (BS). Overweight individuals have a greater risk of cardiorespiratory complications during endoscopy under sedation. This study aimed to investigate the feasibility, tolerance, and cardiovascular stress of transnasal endoscopy (TNE) without sedation in obese patients eligible for BS.


This prospective study enrolled obese adult patients with indication for BS that consented to undergo unsedated preoperative TNE. All examinations were carried out in an outpatient center. The outcomes assessed were endoscopic findings, procedural success, patients’ tolerance according to a visual analogic scale, cardiovascular stress estimated by double product (i.e., systolic blood pressure × heart rate) and adverse events. Statistical analyses were used to compare each patient’s double product among different examination periods.


Ninety-four patients (77.6% female) completed the study, with an average body mass index (BMI) of 53 kg/m2 (range, 35–73.4 kg/m2). There were 63 super-obese individuals (67%), with BMI > 50 kg/m2. In 93 patients (98.9%), unsedated TNE was successfully completed up to the second part of the duodenum. TNE failed in one patient. Tolerance was rated as excellent or good in 95.7%. Minimal cardiovascular stress was noted in obese individuals, whereas the double product remained stable throughout the procedure in super-obese patients. Three patients (3.2%) had self-limited epistaxis.


Unsedated TNE for preoperative endoscopic evaluation of obese patients is feasible, safe, and well tolerated and should be preferentially considered when examining super-obese patients.

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The authors would like to thank Enago ( for the English language review.

The authors would like to thank the Federal University of Minas Gerais and Clinical Hospital for recruiting patients.

Author information

Amaury T. Xavier, MS: Drafting of the manuscript

Arthur V. Alvares: Drafting of the manuscript

Prasad G. Iyer, M.D: Drafting and critical revision of the manuscript

Vitor N. Arantes, M.D: Drafting and critical revision of the manuscript

Correspondence to Amaury Teixeira Xavier.

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All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

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Informed consent was obtained from all individual participants included in the study.

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Xavier, A.T., Alvares, A.V., Iyer, P.G. et al. Unsedated Transnasal Endoscopy for Preoperative Examination of Bariatric Patients: a Prospective Study. OBES SURG 30, 238–243 (2020).

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  • Transnasal endoscopy
  • Obesity
  • Endoscopy without sedation