Observational Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Surg. Jul 27, 2016; 8(7): 513-520
Published online Jul 27, 2016. doi: 10.4240/wjgs.v8.i7.513
Three-dimensional endoanal ultrasound for diagnosis of perianal fistulas: Reliable and objective technique
Marina Garcés-Albir, Stephanie Anne García-Botello, Alejandro Espi, Vicente Pla-Martí, Jose Martin-Arevalo, David Moro-Valdezate, Joaquin Ortega
Marina Garcés-Albir, Joaquín Ortega, Department of General and Digestive Surgery, Hospital Clínico Universitario, 46010 Valencia, Spain
Stephanie Anne García-Botello, Alejandro Espi, Vicente Pla-Martí, Jose Martin-Arevalo, David Moro-Valdezate, Colorectal Unit, Department of General and Digestive Surgery, Hospital Clínico Universitario, 46010 Valencia, Spain
Author contributions: Garcés-Albir M, García-Botello SA and Espi A contributed to study conception and design; Garcés-Albir M and García-Botello SA contributed to data acquisition, data analysis and interpretation, and writing of article; García-Botello SA is a native English speaker; and all the authors contributed to editing, reviewing and final approval of article.
Institutional review board statement: The study was reviewed and approved by the Hospital Clínico Universitario of Valencia Institutional Review Board.
Informed consent statement: All involved persons (subjects or legally authorized representative) gave their informed consent written prior to study inclusion.
Conflict-of-interest statement: None of the authors has conflict of interest of commercial, personal, political, intellectual, or religious.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at garalma@hotmail.com. Participants gave informed consent for data sharing was not obtained but the presented data are anonymized and no risk of identification.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Marina Garcés-Albir, MD, PhD, Department of General and Digestive Surgery, Hospital Clínico Universitario, Avd. Blasco Ibañez 17, 46010 Valencia, Spain. garalma@hotmail.com
Telephone: +34-96-3862600-51233 Fax: +34-96-3864805
Received: January 28, 2016
Peer-review started: January 29, 2016
First decision: March 9, 2016
Revised: April 3, 2016
Accepted: April 14, 2016
Article in press: April 18, 2016
Published online: July 27, 2016
Processing time: 164 Days and 23.2 Hours
Abstract

AIM: To evaluate accuracy of three-dimensional endoanal ultrasound (3D-EAUS) as compared to 2D-EAUS and physical examination (PE) in diagnosis of perianal fistulas and correlate with intraoperative findings.

METHODS: A prospective observational consecutive study was performed with patients included over a two years period. All patients were studied and operated on by the Colorectal Unit surgeons. The inclusion criteria were patients over 18, diagnosed with a criptoglandular perianal fistula. The PE, 2D-EAUS and 3D-EAUS was performed preoperatively by the same colorectal surgeon at the outpatient clinic prior to surgery and the fistula anatomy was defined and they were classified in intersphincteric, high or low transsphincteric, suprasphincteric and extrasphincteric. Special attention was paid to the presence of a secondary tract, the location of the internal opening (IO) and the site of external opening. The results of these different examinations were compared to the intraoperative findings. Data regarding location of the IO, primary tract, secondary tract, and the presence of abscesses or cavities was analysed.

RESULTS: Seventy patients with a mean age of 47 years (range 21-77), 51 male were included. Low transsphincteric fistulas were the most frequent type found (33, 47.1%) followed by high transsphincteric (24, 34.3%) and intersphincteric fistulas (13, 18.6%). There are no significant differences between the number of IO diagnosed by the different techniques employed and surgery (P > 0.05) and, there is a good concordance between intraoperative findings and the 2D-EAUS (k = 0.67) and 3D-EAUS (k = 0.75) for the diagnosis of the primary tract. The ROC curves for the diagnosis of transsphincteric fistulas show that both ultrasound techniques are adequate for the diagnosis of low transsphincteric fistulas, 3D-EAUS is superior for the diagnosis of high transsphincteric fistulas and PE is weak for the diagnosis of both types.

CONCLUSION: 3D-EAUS shows a higher accuracy than 2D-EAUS for assessing height of primary tract in transsphincteric fistulas. Both techniques show a good concordance with intraoperative finding for diagnosis of primary tracts.

Keywords: Tridimensional endoanal ultrasound; High transsphincteric fistula; Perianal fistula; Intersphinteric fistula; Dimensional endoanal ultrasound

Core tip: The authors think that this paper provides new information regarding the diagnosis of perianal fistulas with three-dimensional endoanal ultrasound when compared with the results obtained from two-dimensional endoanal ultrasound, physical examination, and examination under anesthesia. This allows us to validate the technique.