Anorectal Malformation

Figure 19.1 shows the decision-making algorithm for the initial management of male patients with anorectal malformations. When one is called to see a newborn male with an anorectal malformation, a thorough perineal inspection must be performed. This usually gives the most important clues about the type of malformation that the patient has. It is important not to make a decision about colostomy or primary operation before 24 h of life because significant intraluminal pressure is required for the meconium to be forced through a fistula orifice, which is the most reliable sign of the location of the fistula. If meconium is seen on the perineum, it is evidence of a perineal fistula. If there is meconium in the urine, a rectourinary fistula is present.

Radiologic evaluations do not show the real anatomy before 24 h because the rectum is collapsed and does not yet have enough intraluminal pressure to overcome the muscle tone of the sphincters that surround it. Therefore, radiologic evaluations done too early (before 24 h) will most likely reveal the false impression of a "very high rectum."

During the first 24 h, the baby should receive intravenous fluids and antibiotics. The presence of associated defects should be investigated. These include cardiac conditions, esophageal atresia, duodenal atresia, and urologic and spinal defects. An echocardiogram of the heart can be taken. A nasogastric tube is passed to detect the presence of esophageal atresia. An x-ray film of the lumbar spine and the sacrum are helpful

20-24 hrs

Spine Kidney U/S Urinalysis R/O esophageal atresia

Sacrum Spinal U/S Cardiac echo

Re-evaluation and crosstable lateral film

Perineal fistula


Rectal gas below coccyx No associated defects

Consider PSARP with or without colostomy

Rectal gas above coccyx Associated defects Abnormal sacrum Flat Bottom


Fig. 19.1 Decision-making algorithm for male newborns with anorectal malformations (ARM). U/S Ultrasound, PSARP posterior sagittal anorectoplasty, R/O rule out (Reprinted from Pediatric Surgery, 4th ed., Ashcraft, Whitfield & Murphy eds. Peña A, Levitt MA. Imperforate Anus and Cloacal Malformations, p 501, Elsevier Saunders, Philadelphia (2005), with permission from Elsevier.)

to determine the presence of associated spinal and sacral anomalies. A spinal ultrasound in the newborn period is a good screen for tethered cord and other spinal anomalies. An ultrasound of the abdomen will rule out the presence of hydronephrosis [1]. If the baby has signs of a perineal fistula, an anoplasty can be performed during the first 48 h of life without a protective colostomy (Fig. 19.2). If the baby's clinical condition warrants waiting to do surgery, such as for a premature baby or one with an associated cardiac defect, dilatations of the fistula with a delayed repair is acceptable. Such a baby must be watched closely to be sure that the colon is adequately emptying through the fistula. After 24 h, if no meconium is seen on the perineum, a cross-table, lateral x-ray film with the baby in a prone position often shows the location of the distal rectum. If the gas in the rectum is located below the coccyx and the baby is in a good condition with no significant associated defects, depending on the surgeon's experience, a posterior sagittal opera

Cloacal Malformation Status Colostomy
Fig. 19.2 Newborn anoplasty

tion without a protective colostomy can be considered (Fig. 19.3). If the rectal gas is seen located above the coccyx and the patient has meconium in the urine, or has significant associated defects, an abnormal sacrum, or a flat bottom, a colostomy is the safest approach, with postponement of the main repair for a subsequent operation [2]. The definitive operation can be performed as early as 4-8 weeks later provided the baby is gaining weight normally. Performing the definitive repair early has important advantages for the patient, including less time with an abdominal stoma, less size discrepancy between the proximal and distal bowel at the time of colostomy closure, easier anal dilatation, and avoidance of psychological sequelae from painful perineal maneuvers. In addition, placing the rectum in the right location early in life, and using it, may represent an advantage in terms of the potential for acquired local sensation [3].

A temptation to repair these defects without a protective colostomy always exists [4, 5]. Such a repair without colostomy is performed without adequate anatomic information about the specific type of defect. Catastrophic complications have been seen in patients in whom the surgeon did not have a distal colostogram, approached the patients posterior sagit-tally looking for the rectum, and during the search for the rectum, injured to important structures (urethra, bladder, ureters, vas deferens, or seminal vesicles) occurred [6].

Anorectal Malformation Ray
Fig. 19.3 Radiograph of cross-table lateral x-ray

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