Abstract
Background
In complex fistula-in-ano, preoperative imaging can help identify secondary tracts and abscesses that can be missed, leading to recurrence. We evaluated hydrogen peroxide-enhanced endoanal ultrasound (PEEUS) in the characterization of fistula compared with standard clinical and operative assessment.
Methods
Patients with complex fistula-in-ano treated between February 2008 and May 2009 at our institution were prospectively evaluated by PEEUS with recording of the preoperative clinical examination and intraoperative details of the fistula. Of the 135 patients with fistula-in-ano, 68 met the inclusion criteria for complex fistula-in-ano. Correlation of clinical findings and PEEUS to the gold standard intraoperative findings was assessed in characterizing the fistula. The percent agreement between the clinical and PEEUS findings against the gold standard was derived, and the kappa statistic for agreement was determined.
Results
The mean age of the cohort was 42.54 ± 10.86 years. The fistula tracts were curvilinear, high, and transsphincteric in 16 (23.53 %), 8 (11.76 %), and 42 (61.76 %) patients, respectively. Secondary tracts and associated abscess cavities were seen in 28 (33.82 %) and 35 (51.47 %) patients, respectively. PEEUS correlated better than clinical examination with regard to site (92.65 vs 79.41 %; p < 0.001) and course (91.18 vs 77.94 %; p < 0.001) of secondary tract and associated abscesses (89.71 vs 80.88 %; p = 0.02). There was a trend of better correlation of PEEUS compared to clinical examination in classifying the primary tract as per Park’s system (88.24 vs 79.41 %; p = 0.06), but it did not reach statistical significance. PEEUS and clinical examination were comparable in correlation of the level of the primary tract (kappa: 0.86 vs 0.78; p = 0.22) and the site of internal opening (kappa: 0.97 vs 0.89; p = 0.22). The operative decision was changed in 13 (19.12 %) subjects based on PEEUS findings.
Conclusions
PEEUS is a feasible and efficient tool in the routine preoperative assessment of complex fistula-in-ano.
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References
Toyonaga T, Tanaka Y, Song J et al (2008) Comparison of accuracy of physical examination and endoanal ultrasonography for preoperative assessment in patients with acute and chronic anal fistula. Tech Coloproctol 12:217–223
No authors listed (1996) Practice parameters for treatment of fistula-in-ano: supporting documentation. The Standards Practice Task Force. The American Society of Colon and Rectal Surgeons. Dis Colon Rectum 39:1363–1372
West RL, Zimmerman DD, Dwarkasing S et al (2003) Prospective comparison of hydrogen peroxide-enhanced three-dimensional endoanal ultrasonography and endoanal magnetic resonance imaging of perianal fistulas. Dis Colon Rectum 46:1407–1415
Lunniss PJ, Armstrong P, Barker PG, Reznek RH, Phillips RK (1992) Magnetic resonance imaging of anal fistulae. Lancet 340:394–396
Buchanan GN, Halligan S, Bartram CI, Willuiams AB, Tarroni D, Cohen CR (2004) Clinical examination, endosonography and mr imaging in preoperative assessment of fistula in ano: comparison with outcome-based reference standard. Radiology 233:674–681
Buchanan GN, Bartram CI, Williams AB, Halligan S, Cohen CR (2005) Value of hydrogen peroxide enhancement of three-dimensional endoanal ultrasound in fistula-in-ano. Dis Colon Rectum 48:141–147
Cheong DM, Nogueras JJ, Wexner SD, Jagelman DG (1993) Anal endosonography for recurrent anal fistulas: image enhancement with hydrogen peroxide. Dis Colon Rectum 36:1158–1160
Sudol-Szopinska I, Jakubowski W, Szczepkowski M (2002) Contrast-enhanced endosonography for the diagnosis of anal and anovaginal fistulas. J Clin Ultrasound 30:145–150
Sudol-Szopinska I, Jakubowski W, Szczepkowski M (2003) Usefulness of hydrogen peroxide enhancement in diagnosis of anal and ano-vaginal fistulas. Eur Radiol 13:1080–1084
Parks AG, Gardon PH, Hardcastle JD (1976) A classification of fistula-in-ano. Br J Surg 63:1–12
Choen S, Burnett S, Bartram CI, Nicholls RJ (1991) Comparison between anal endosonography and digital examination in the evaluation of anal fistulae. Br J Surg 78:445–447
Poen AC, Felt-Bersma RJ, Eijsbouts QA, Cuesta MA, Meuwissen SG (1998) Hydrogen peroxide-enhanced transanal ultrasound in the assessment of fistula-in-ano. Dis Colon Rectum 41:1147–1152
Ratto C, Gentile E, Merico M et al (2000) How can the assessment of fistula-in-ano be improved? Dis Colon Rectum 43:1375–1382
Navarro-Luna A, García-Domingo MI, Rius-Macias J, Marco-Molina C (2004) Ultrasound study of anal fistulas with hydrogen peroxide enhancement. Dis Colon Rectum 47:108–114
Ratto C, Grillo E, Parello A, Costamagna G, Doglietto GB (2005) Endoanal ultrasound-guided surgery for anal fistula. Endoscopy 37:722–728
Moscowitz I, Baig MK, Nogueras JJ et al (2003) Accuracy of hydrogen peroxide enhanced endoanal ultrasonography in assessment of the internal opening of anal fistula complex. Tech Coloproctol 7:133–137
Buchanan GN, Bartram CI (2003) Imaging anal fistula. Radiol Clin N Am 41:443–457
Pascual Migueláñez I, García-Olmo D, Martínez-Puente MC, Pascual Montero JA (2005) Is routine endoanal ultrasound useful in anal fistulas? Rev Esp Enferm Dig 97:323–327
Cho DY (1999) Endosonographic criteria for an internal opening of fistula-in-ano. Dis Colon Rectum 42:515–518
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Nagendranath, C., Saravanan, M.N., Sridhar, C. et al. Peroxide-enhanced endoanal ultrasound in preoperative assessment of complex fistula-in-ano. Tech Coloproctol 18, 433–438 (2014). https://doi.org/10.1007/s10151-013-1067-y
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DOI: https://doi.org/10.1007/s10151-013-1067-y