Classification

ARM represent a wide spectrum of defects and conditions. A clear understanding of normal anorectal anatomy and the different types of ARM is necessary for both the planning of surgery and the procedure itself. An appreciation of the classification systems is useful in practice to the surgeon. This is, however, much easier said than done. The classification systems are notoriously difficult and unwieldy. There are multiple classifications in use in different centres throughout the world, making comparisons difficult. A brief examination of the literature demonstrates the multitude of classification systems available and in daily use. In order to explain the classifications that have been proposed over the years and that still exist we will discuss the history and development of the classification systems

Amussat, the father of the proctoplasty in 1835, was the first to attempt a classification system of ARM [63]. He described five groups: (1) a narrowed anus, (2) a closed anal membrane, (3) rectum interrupted by a septum at some distance from the opening, (4) imperforate anus and (5) the presence of a rectal fistula. Numerous other authors such as Stieda in 1903, Jones in 1904, Breener in 1915 and Frazer in 1926 created clinical classification systems [58]. However, it was the classification system of Ladd and Gross (1934) that prevailed and became the standard (Table 8.5) [64].

In 1963 a Melbourne team lead by Stephens classified the lesions into two categories, either high or low (Table 8.6). This classification recognises the importance of the puborectalis muscle and its effects in continence. Lesions above the pubococcygeal (PC) line were described as high and below as low. The PC line is drawn on a lateral pelvic radiograph "invertogram" between the midpoint of the pubis and the inferior aspect of the sacrum [65]. It represents the level of the levator ani attachment to the pelvic wall.

The Melbourne classification allowed Stephens to pioneer the sacrococcygeal approach in order to preserve the puborectalis. Although this classification was deficient in clinical information and overly

Table 8.5 Ladd and Gross classification 1934 [64]

Type

Anomaly

I

Anal and anorectal stenosis

II

Imperforate anus

III

Imperforate anus with blind

ending pouch with fistula

IV

Rectal Atresia

Table 8.6 Stephens and Smith 1963 classification based on em-bryological concepts

B: Secondary defects after Partition

Rectal atresia

Rectal atresia

Rectal deformities

A: Defects of the perineum

1. Anterior perineal anus

1. Anterior perineal anus Perineal Vulvar

2. Anovestibular fistula

3. Perineal groove

4. Perineal canal

B: Defects of the genital fold

1. Covered anus complete

1. Covered anus complete

2. Anocutaneous fistula

2. Anocutaneous fistula

3. Anobulbar fistula

3. Anovulvar fistula

C: Defects of the proctodeal pit

1. Anorectal agenesis

1. Anorectal agenesis

2. Imperforate anal membrane

2. Imperforate anal membrane

3. Anal stenosis

(i) Covered anal stenosis

(ii) Anal membrane stenosis

(iii) Anorectal stenosis

3. Anal stenosis

(i) Covered anal stenosis

(ii) Anal membrane stenosis

(iii) Anorectal stenosis

Unclassified

1. Vesicointestinal fissure

2. Duplication of the rectum and anus

3. Combination of usual deformities

Male

Female

Anorectal deformities

A: Defect of the partition of the internal cloaca

1. Anorectal agenesis (no fistula)

1. Anorectal agenesis (no fistula)

2. Rectovesical fistula

2. Rectovesical fistula

3. Rectourethral fistula

3. Rectourethral fistula

4. Rectovaginal fistula

5. Rectovestibular fistula

Table 8.6 Stephens and Smith 1963 classification based on em-bryological concepts

Table 8.7 Anorectal anomalies based on a simplified Santulli classification [66]

Table 8.8 A simplified version of the 'International' classification

A. Without fistula

B. With fistula Rectovaginal fistula low Rectovestibular fistula

1. Anal agenesis

A. Without fistula

B. With fistula Rectobulbar fistula

2. Anorectal stenosis

2. Anorectal stenosis

Low

1. At normal anal site Covered anus - complete Covered anal stenosis

1. At normal anal site Covered anus - complete Covered anal stenosis

2. At perineal site Anocutaneous fistula Anterior perineal anus

2. At perineal site Anocutaneous fistula Anterior perineal anus

3. At vulvar site Vulvar anus Anovulvar fistula Anovestibular fistula

Miscellaneous

Anal membrane stenosis

Anal membrane stenosis

Imperforated anal membrane

Imperforated anal membrane

Perineal groove

Perineal groove

Perineal canal

Perineal canal

Type of anomaly

Female

Male

Low, infralevator

I. Anal stenosis

I. Anal stenosis

II. Anal membrane

II. Anal membrane

III. Anal agenesis

III. Anal agenesis

A. Without fistula

A. Without fistula

B. With fistula

B. With fistula

High, supralevator

I. Rectal agenesis

I. Rectal agenesis

A. Without fistula

A. Without fistula

B. With fistula

B. With fistula

II. Rectal atresia

II. Rectal atresia

Table 8.7 Anorectal anomalies based on a simplified Santulli classification [66]

Type of anomaly

Female

Male

High

1. Anorectal agenesis

1. Anorectal agenesis

A: Rectal atresia

A: Rectal atresia

Rectocloacal fistula Rectovaginal/high

Rectovesical fistula Rectourethral fistula

2. Rectal atresia

2. Rectal atresia

Table 8.8 A simplified version of the 'International' classification

Rectobulbar FistulaAnovestibular Rectovestibular FistulaAnorectal Malformation ClassificationAnorectal Malformation ClassificationAnorectal Malformation ClassificationAnorectal Malformation MaleFistula Rectovaginal Female GenitalFemale Genital Deformities

MISCELLANEOUS DEFORMITIES

MALE

Anus at normal site, but proctodeal membrane intact. Puborectalis normal; no internal sphincter below the anal valves; deep external sphincter intact, but rudimentary superficial sphincter.

Diagnosis:

(i) Superficially normal anus, but membrane may bulge with meconium, or be found on digital examination, (ii) No genital fold defects, (iii) Gas well below I point on invertography.

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Responses

  • juhana
    How is PC line &I Line can be drawn in in invertogram of ARM emedicine?
    3 years ago
  • Paul
    How we will draw the PC line and I line In invertogram of ARM emedicine?
    3 years ago

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