Anal Fistula: Levovist®-Enhanced Endoanal Ultrasound

Abstract

Levovist-enhanced ultrasound is better at assessing anal fistula than physical examination and conventional ultrasound. However, a future trial comparing Levovist, hydrogen peroxide, and magnetic resonance imaging is needed to establish which is the most cost-effective preoperative imaging technique to use.

Complex perirectal sepsis: clinical classification and imaging

“…The accuracy of primary fistula diagnosis with unenhanced ultrasonography varies from 64% to 94%, with delineation of the internal opening in 28%-93% of cases and of horseshoe- 86 ing in 23%-81% of patients [18,[35][36][37][38][39][40][41][42][43]. Similar comparisons are made for enhanced EAUS, with reported rates for definition of the primary track and fistula anatomy ranging from 60% to 95%, delineation of the internal opening in 48%-94% of cases and horseshoeing in 75%-92% of patients [6,17,39,40,[44][45][46][47][48][49][50][51][52]. Comparative studies between enhanced and unenhanced ultrasonography suggested a significant advantage for the routine use of hydrogen peroxide in all these areas of fistula assessment [39-41, 48-50, 52] as well as in the distinction between linear and curvilinear tracks, a finding which has been suggested as being of some importance in sphincter preservation for recurrent complicated fistulae [53].…”

“…Zbar, N.C. Armitage: Complex perirectal sepsis ticularly successful in the delineation of multiple fistula tracks as occurs in one-third of patients with perianal Crohn's disease as well as in the demonstration of anovaginal fistulae in these patients [40,46]. Recent administration of Levovist, a galactose (C6H12O6) and palmitic acid (C16H32O2) microparticle ultrasonic enhancer, has shown little specific advantage over hydrogen peroxide, with relatively low yields for definition of the internal opening, although the optimal dosage of Levovist is at present unclear [51]. Specialized ultrasonic classification systems still require validation and some proof of cost-effectiveness as principal management tools, although it is likely that these technologies assist in the performance of sphincter-saving techniques in high fistulae, in primary seton deployment and in the differentiation of pilonidal and perineal sepsis from perianal infections [55].…”

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“…The following clinical applications of EV-CEUS have been described in case studies: percutaneous nephrostomy [80], biliary tract imaging via percutaneous transhepatic cholangiography and drainage (PTCD) [81], abscess drainage [82], swallow CEUS for imaging Zenker's diverticulum, voiding vesicoureteral reflux sonography [83,84], salivary gland duct imaging [85], contrast-enhanced hysterosalpingo-sonography (CE-HyCoSy [86], biliary tract imaging via endoscopic retrograde cholangiography (ERCP) [87] and fistula imaging [88].…”

Ultrasonographic assessment of patients referred with chronic anal pain to a tertiary referral centre

“…The accuracy of diagnosis of the presence and location of perirectal infection using endoanal sonography has been well described, alone [15], with hydrogen peroxide [16] or using specific ultrasonic contrast enhancement [17]. Recently, our group has shown that enhanced transperineal sonography may be accurate in delineating the presence of deep-seated anorectal abscesses [18,19], providing complementary information to that obtained with conventional anal endosonography.…”