Diversities of H-type anorectal malformation: a systematic review on a rare variant of the Krickenbeck classification

Abstract

Congenital H-type fistula is a rare congenital rectourogenital connection with an external anal opening in a normal or ectopic position. A systematic review was done to study the anatomical types of congenital H-type fistula, embryology, clinical presentation, relative gender distribution, associated anomalies, investigative modalities, and recent advances in treatment of these lesions. A PubMed search included H-type anorectal malformation; H-type anorectal malformations; H-type anorectal; and H-type congenital anorectal that gave 9;43;76;26 abstracts, respectively. Relevant studies and cited articles were studied omitting duplicate search. The reported incidence is 0.1-16 % of all anorectal malformation. The H-type anorectal malformation is 2.5-6 times more common in females and usually associated with a normal anus. In males, the anomaly is usually a variant with an ectopic anus or a perineal fistula. Anatomical types include anovestibular; rectovestibular; rectovaginal fistula in females and rectourethral (bulbar, prostatic, bladder neck) and rectovesical fistula in males. Variants identified include H-type fistula with perineal fistula, perineal groove, H-type sinus, H-type canal, and acquired H-type fistula. This review compiles the available literature over last six decades. Various surgical corrective procedures have been described. The high recurrence decreases with a learning curve and experience.

Transperineal Ultrasound as an Adjunctive Modality in the Evaluation of ‘H or N’ Type of Recto-urethral Fistula: Technical Note

“…H-type configuration is an extremely rare variant in the spectrum of anorectal malformations described under the recent Krickenbeck classification. 3 It differs from other ARMs in the fact that usually the anal opening is in normal location 3,4 . Majority of these patients have relatively continent sphincters, and abnormal passage of urine through the anal canal is often the only clinical clue.…”

“…In boys, they are associated with increased rates of major congenital anomalies. 2,3 In the presence of colostomy, an augmented pressure colostogram with or without retrograde or micturating cystourethrogram is the investigation of choice. 2 In children, transperineal ultrasound (TPUS) has been used in the evaluation of anorectal malformations, Müllerian anomalies, and disorders of sex differentiation (DSDs).…”

“…In boys, they are associated with increased rates of major congenital anomalies. 2 3 In the presence of colostomy, an augmented pressure colostogram with or without retrograde or micturating cystourethrogram is the investigation of choice. 2 …”

H-type Rectourethral Fistula with Anal Stenosis in a Male Patient: A Case Report with Literature Review

“…The associated renal or intestinal anomalies (TEF) and even VACTERL spectrum have been reported in male patients with an H-type ARM because of similar septation abnormalities [4]. et al have summarized these associated anomalies in the acronym VACTERG: vertebral, anorectal, cardiac, tracheoesophageal, renal, and genitourinary [14]. Lang EK has reported a rare association with H-type tracheoesophageal fistula in only two cases [15].…”

“…Lang EK has reported a rare association with H-type tracheoesophageal fistula in only two cases [15]. The diagnosis of H-type ARM in males is challenging with the presence of a normal anal opening; however, the abnormal (ectopic) anus should raise the suspicion of this anomaly, especially when associated with recurrent UTIs [14]. In females, the passage of stool out of the vagina is the usual presenting feature.…”