Abstract
Background
To correlate the operative findings of patients with fistula-in-ano with preoperative MRI and quantify the information added with MRI.
Methods
All consecutive fistula-in-ano patients operated between July 2013 and May 2015 were prospectively enrolled. Preoperative MRI was done in every patient. The details of tracts, internal opening and “complex parameters” (additional tract or additional internal opening, horseshoe tract, associated abscess and supralevator extension) found at surgery were compared to the findings determined by MRI.
Results
A total of 229 patients (424 tracts) with mean age—49.0 ± 11.3 years were included. M/F 198/31. James hospital classification: Type I 58, II 20, III 49, IV 86 and V 16. The sensitivity and specificity of MRI in diagnosing fistula tracts were 98.8 and 99.7%, respectively, and in identifying internal opening were 97.7 and 98.6%, respectively. MRI added significant information in 46.7% (107/229) patients which was presence of additional tracts in 71 (66.3%), horseshoe tract in 63 (58.8%), supralevator extension in 16 (14.9%), unsuspected abscess in 11 (10.3%) and multiple internal openings in one patient (1%). The proportion of simple/complex fistula (based on history and clinical examination alone) was 32.8/67.2% which changed to 21.4/78.6% after the MRI scan. MRI added significant information about unsuspecting complex parameters which were missed on history and clinical examination in more than one-third (26/75: 34.6%) of simple fistulae and more than half (81/154: 52.5%) of already known complex fistulae.
Conclusions
MRI is highly accurate in diagnosing fistula-in-ano and added significant information about unsuspected complex parameters in over one-third (34.6%) of simple and in half (52.5%) of complex fistula-in-ano.
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References
Kuijpers HC, Schulpen T (1985) Fistulography for fistula-in-ano. Is it useful? Dis Colon Rectum 28:103–104
Halligan S (1998) Imaging fistula-in-ano. Clin Radiol 53:85–95
Hussain SM, Stoker J, Schouten WR et al (1996) Fistula in ano: endoanal sonography versus endoanal MR imaging in classification. Radiology 200:475–481
Maier AG, Funovics MA, Kreuzer SH et al (2001) Evaluation of perianal sepsis: comparison of anal endosonography and magnetic resonance imaging. J Magn Reson Imaging 14:254–260
Buchanan GN, Halligan S, Bartram CI et al (2004) Clinical examination, endosonography, and MR imaging in preoperative assessment of fistula in ano: comparison with outcome-based reference standard. Radiology 233:674–681
Siddiqui MR, Ashrafian H, Tozer P et al (2012) A diagnostic accuracy meta-analysis of endoanal ultrasound and MRI for perianal fistula assessment. Dis Colon Rectum 55:576–585
Halligan SJ Stoker (2006) Imaging of fistula in ano. Radiology 239:18–33
de Miguel Criado J, del Salto LG, Rivas PF et al (2012) MR imaging evaluation of perianal fistulas: spectrum of imaging features. Radiographics 32:175–194
Buchanan GN, Halligan S, Williams AB et al (2003) Magnetic resonance imaging for primary fistula in ano. Br J Surg 90:877–881
Beets-Tan RG, Beets GL, van der Hoop AG et al (2001) Preoperative MR imaging of anal fistulas: does it really help the surgeon? Radiology 218:75–84
Buchanan G, Halligan S, Williams A et al (2002) Effect of MRI on clinical outcome of recurrent fistula-in-ano. Lancet 360:1661–1662
Morris J, Spencer JA, Ambrose NS (2000) MR imaging classification of perianal fistulas and its implications for patient management. Radiographics 20:623–635 discussion 635–637
Parks AG, Gordon PH, Hardcastle JD (1976) A classification of fistula-in-ano. Br J Surg 63:1–12
Whiteford MH, Kilkenny J 3rd, Hyman N et al (2005) Practice parameters for the treatment of perianal abscess and fistula-in-ano (revised). Dis Colon Rectum 48:1337–1342
Beckingham IJ, Spencer JA, Ward J et al (1996) Prospective evaluation of dynamic contrast enhanced magnetic resonance imaging in the evaluation of fistula in ano. Br J Surg 83:1396–1398
Mullen R, Deveraj S, Suttie SA et al (2011) MR imaging of fistula in ano: indications and contribution to surgical assessment. Acta Chir Belg 111:393–397
Schwartz DA, Wiersema MJ, Dudiak KM et al (2001) A comparison of endoscopic ultrasound, magnetic resonance imaging, and exam under anesthesia for evaluation of Crohn’s perianal fistulas. Gastroenterology 121:1064–1072
Orsoni P, Barthet M, Portier F et al (1999) Prospective comparison of endosonography, magnetic resonance imaging and surgical findings in anorectal fistula and abscess complicating Crohn’s disease. Br J Surg 86:360–364
(1996) Practice parameters for treatment of fistula-in-ano. The standards practice task force. The American Society of Colon and Rectal Surgeons. Dis Colon Rectum 39:1361–1362
Chapple KS, Spencer JA, Windsor AC et al (2000) Prognostic value of magnetic resonance imaging in the management of fistula-in-ano. Dis Colon Rectum 43:511–516
Lunniss PJ, Barker PG, Sultan AH et al (1994) Magnetic resonance imaging of fistula-in-ano. Dis Colon Rectum 37:708–718
Spencer JA, Chapple K, Wilson D et al (1998) Outcome after surgery for perianal fistula: predictive value of MR imaging. AJR Am J Roentgenol 171:403–406
Seow-Choen F, Nicholls RJ (1992) Anal fistula. Br J Surg 79:197–205
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Garg, P., Singh, P. & Kaur, B. Magnetic Resonance Imaging (MRI): Operative Findings Correlation in 229 Fistula-in-Ano Patients. World J Surg 41, 1618–1624 (2017). https://doi.org/10.1007/s00268-017-3886-x
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DOI: https://doi.org/10.1007/s00268-017-3886-x