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19.1 Males
Figure 19.1 shows the decision-making algorithm for the initial management of male patients with anorec- tal malformations. When one is called to see a new- born male with an anorectal malformation, a thor- ough 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 intra- luminal pressure is required for the meconium to be forced through a fistula orifice, which is the most reli- able sign of the location of the fistula. If meconium is seen on the perineum, it is evidence of a perineal fis- tula. If there is meconium in the urine, a rectourinary fistula is present.
Radiologic evaluations do not show the real anat- omy 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 sur- round it. Therefore, radiologic evaluations done too early (before 24 h) will most likely reveal the false im- pression of a “very high rectum.”
During the first 24 h, the baby should receive intra- venous fluids and antibiotics. The presence of associ- ated defects should be investigated. These include car- diac 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
Contents
19.1 Males . . . 289 19.2 Females . . . 290 19.3 Colostomy . . . 292
References . . . 292
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-
19 Management in the Newborn Period
Marc A. Levitt and Alberto Peña
Fig. 19.1 Decision-making algorithm for male newborns with anorectal malformations (ARM). U/S Ultrasound, PSARP pos- terior sagittal anorectoplasty, R/O rule out (Reprinted from Pediatric Surgery, 4th ed., Ashcraft, Whitfield & Murphy eds.
Peña A, Levitt MA. Imperforate Anus and Cloacal Malforma- tions, p 501, Elsevier Saunders, Philadelphia (2005), with per- mission from Elsevier.)
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 sa- crum, or a flat bottom, a colostomy is the safest ap- proach, 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, eas- ier anal dilatation, and avoidance of psychological se- quelae 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 pro- tective colostomy always exists [4, 5]. Such a repair without colostomy is performed without adequate anatomic information about the specific type of de- fect. 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) oc- curred [6].
19.2 Females
Figure 19.4 shows a decision-making algorithm for the initial management of female patients. As in males, the perineal inspection is the most important step in the diagnosis and decision-making. The first 24 h should also be used to rule out important associ- ated defects, as described previously.
The perineal inspection may disclose a single perineal orifice, which establishes the diagnosis of a cloaca. The clinician should know that such patients have a high likelihood (90%) of having an associated urologic defect. The patient needs a urologic evalua- tion and the presence of hydrocolpos should be ruled out by ultrasound.
Babies with a cloaca should undergo a diverting colostomy. It is important to perform the colostomy proximally enough to allow for the future repair of the malformation without interference from the co- lostomy. The surgeon must leave enough redundant distal rectosigmoid to allow a pull-through and, if needed, a vaginal reconstruction.
During the opening of the colostomy, it is manda- tory to drain a hydrocolpos if present [7]. If the hy- drocolpos is not large enough to reach the abdominal wall above the bladder, it can be drained with a rubber tube. Because a significant number of these patients have two hemivaginas, the surgeon must be certain that the tube inserted into the hydrocolpos is drain-
Fig. 19.2 Newborn anoplasty Fig. 19.3 Radiograph of cross-table lateral x-ray
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19 Management in the Newborn Period
ing both hemivaginas. Occasionally, the surgeon has to open a window in the vaginal septum in order to drain both with a single tube. The hydrocolpos can be so large that it may produce respiratory distress; vagi- nas that large may be drained by suturing the vaginal wall to the abdominal wall as a stoma.
Drainage of the hydrocolpos will relieve the ure- teral obstruction, as the dilated vagina compresses the trigone. In rare cases, the bladder remains dis- tended, and this may be evidence of particularly long, or narrow common channel. In such circumstances, the baby may require a vesicostomy or a suprapubic cystotomy. During the same anesthetic, it is helpful to perform an endoscopy to try to determine the anat- omy, particularly the length of the common channel, which will help planning of the definitive operation.
The perineal inspection may show the presence of a perineal fistula, for which a primary anoplasty with- out a colostomy may be performed. Occasionally, the surgeon may have to care for a baby with severe asso- ciated defects or one who is very premature. If that is the case, dilatation of the fistula facilitates emptying of the colon, and a definitive operation can be planned for a future time.
The presence of a rectovestibular fistula is the most common finding in female patients. This malforma- tion can be repaired during the neonatal period with- out a protective colostomy. A newborn pull-through in such patients is ideal, but unfortunately also rep-
resents the most common source of complications in these patients. To decide to repair this malformation primarily or to open a colostomy is a personal deci- sion that should be based on the experience of the surgeon. Colostomy is still the most effective way to protect the pull-through.
Occasionally (less than 10% of the cases) there is no visible fistula and there is no meconium coming out from either the perineum or the urinary tract, even after 24 h of observation. For this small group of patients, a cross-table, lateral film is valuable. If the x- ray shows the gas in the rectum located very near the skin, it is likely that the patient has a perineal fistula.
If the patient has a blind rectum located about 1 or 2 cm above the skin, the patient probably suffers from an imperforate anus with no fistula. One can con- sider, in this case, performing a primary operation without a colostomy, depending on the surgeon’s ex- perience (many of these patients with no fistula also have Down syndrome) [8].
Patients with a rectovestibular fistula who are very sick or premature can have dilatations of the fistula to allow decompression of the colon, with a repair to be performed later in life. That repair can be done with a protective colostomy or in a primary fashion, de- pending again on the surgeon’s experience.
When patients with rectovestibular fistulas are repaired primarily in the newborn period, we rec- ommend keeping them hospitalized for 5 days with
Fig. 19.4 Decision-making al- gorithm for female newborns with ARM. Urol. Urological (Re- printed from Pediatric Surgery, 4th ed., Ashcraft, Whitfield &
Murphy eds. Peña A, Levitt MA.
Imperforate Anus and Cloacal Malformations, p 502, Elsevier Saunders, Philadelphia (2005), with permission from Elsevier.)
nothing by mouth, and on parenteral nutrition. On the other hand, when the patients are subjected to a primary repair of a perineal fistula or rectovestibular fistula later in life, strict preoperative bowel irrigation is vital in order to be sure that the intestine is com- pletely clean. We insert a central venous line and keep the patient hospitalized for 7–10 days with nothing by mouth, receiving parenteral nutrition. With this regi- men, there have been no cases of perineal infection.
19.3 Colostomy
A divided descending colostomy is ideal for the man- agement of anorectal malformations (Fig. 19.5). The completely diverting colostomy provides bowel de- compression as well as protection for the final repair of the malformation. In addition, this type of colos- tomy facilitates the distal colostogram, which repre- sents the most accurate diagnostic study for deter- mining the anatomy of these defects [9].
A descending colostomy has advantages over a right or transverse colostomy [10, 11]. There is a relatively short segment of defunctionalized distal colon. Atro- phy of the bowel distal to a more proximal colostomy
and development of a microcolon with megarectosig- moid may result when a higher colostomy is utilized.
Mechanical cleansing of the distal colon prior to the definitive repair is much less difficult when the colos- tomy is located in the descending colon. In the case of a large rectourethral fistula the patient may pass urine into the colon, whereas a more distal colostomy al- lows urine to escape through the distal stoma without significant absorption. If urine remains in the colon and is absorbed, metabolic acidosis may develop.
Loop colostomies permit the passage of stool from the proximal stoma into the distal bowel, which produces urinary tract infection, distal rectal pouch dilatation, and fecal impaction. Prolonged distention of the rectal pouch may produce irreversible bowel damage, leading to a significant bowel hypomotility disorder and severe constipation later in life. Loop co- lostomies are also prone to prolapse [11].
A colostomy created too distal in the area of rec- tosigmoid may interfere with the mobilization of the rectum during the pull-through and is a common er- ror.
References
1. Peña A, Hong AR (1999) Anorectal malformations – the state of the art. Colon Rectal Surg 2:1–19
2. Shaul DB, Harrison EA (1997) Classification of anorectal malformations – initial approach, diagnostic tests and co- lostomy. Semin Pediatr Surg 6:187–195
3. Freeman NV, Burge DM, Soar JS, et al (1980) Anal evoked potentials. Z Rinderchir 31:22–30
4. Goon HK (1990) Repair of anorectal anomalies in the neonatal period. Pediatr Surg Int 5:246–249
5. Moore TC (1990) Advantages of performing the sagittal anoplasty operation for imperforate anus at birth. J Pedi- atr Surg 25:276–277
6. Hong AR, Rosen N, Acuña MF, Peña A, Chaves L, Rodri- guez G (2002) Urological injuries associated with the re- pair of anorectal malformations in male patients. J Pediatr Surg 37:339–344
7. Levitt MA, Peña A (2005) Pitfalls in the management of newborn cloacas. Pediatr Surg Int 21:264–269
8. Torres P, Levitt MA, Tovilla JM, Rodriguez G, Peña A (1998) Anorectal malformations and Down’s syndrome. J Pediatr Surg 33:1–5
9. Gross GW, Wolfson PJ, Peña A (1991) Augmented-pres- sure colostogram in imperforate anus with fistula. Pediatr Radiol 21:560–563
10. Wilkins S, Peña A (1988) The role of colostomy in the management of anorectal malformations. Pediatr Surg Int 3:105–109
Fig. 19.5 Ideal colostomy (Reprinted from Atlas of Surgical Management of Anorectal Malformations, Peña A. Colostomy, p 19, Springer-Verlag, Inc. (1989), with permission of Springer Science and Business Media.)
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11. Peña A, Krieger M, Levitt MA (2005) Colostomy in ano- rectal malformations: a procedure with serious but pre- ventable complications. J Pediatr Surg 41:748–756 12. Peña A, Levitt MA (2005) Imperforate anus and cloacal
malformations. In: Ashcraft KW, Holcomb W, Murphy JP (eds) Pediatric Surgery 4th edn. Elsevier Saunders, Phila- delphia, pp 501–502
13. Peña A (1989) Colostomy. In: Peña A (ed) Atlas of surgical management of anorectal malformations, Springer-Ver- lag, New York, pp 26–44
