All anorectal malformations can be approached posterior sagittally using a posterior anorectoplasty (PSARP). Approximately 40% of patients with cloaca may additionally need a laparotomy to complete the repair. Only 10% of male patients may require entering of the abdomen (via laparoscopy or laparotomy) to mobilize a very high rectum.
The basis of the posterior sagittal approach is the creation of an incision in the midline between both buttocks, the length of the incision varies depending on the type and height of the malformation. The patient is placed in prone position with the pelvis elevated. The sphincter mechanism is divided in the midline. Excellent exposure is obtained, and nerves and muscles are not damaged. The anatomic characteristics of the malformations are recognized, the rectum is separated from the genitourinary tract, the limits of the sphincter mechanism are electrically determined, and the rectum is mobilized sufficiently to reach the perineum and the sphincter mechanism is reconstructed around it. Via a posterior sagittal approach, all these maneuvers are performed under direct vision, which helps to preserve important anatomic structures.
A posterior sagittal approach should not be attempted without a technically adequate distal colostogram, the best study to determine the exact position of the rectum and the fistula. Exploring a patient posterior sagittally without this basic information risks damaging nerves and other important structures. (In perineal and vestibular fistula cases the rectal position is known, so no contrast study is needed). If the rectum is high, at the bladderneck, and the surgeon does not know this, other midline structures (bladderneck, vas deferens, seminal vesicles, prostate, ectopic ureters) can be injured.
Males with Anorectal Malformations
Minimal PSARP for Rectoperineal Fistula
In these malformations, the repair serves a dual purpose: first, to move the rectal opening back to be placed within the limits of the sphincter mechanism and, second, to create an adequately sized anus. The fistula is consistently located 1 to 2 cm anterior to the center of the sphincter; thus, the degree of rectal dissection necessary is rather minimal. The most common and feared operative complication is urethral damage. To prevent this, a Foley catheter must be inserted and meticulous technique must be used during the dissection of the anterior rectal wall, as the rectum is intimately attached to the urethra. The patient is placed in the prone position; a 2-cm incision is made dividing the posterior superficial portion of the sphincter. Multiple 6-0 silk sutures are placed at the mucocutaneous junction of the fistula in order to exert uniform traction, which facilitates the dissection. Sometimes the fistula is so small that it requires a lacrimal probe to be demonstrated.
With the lacrimal probe in place, the fistula can be unroofed until a reasonable caliber rectal opening is found, and the multiple silk stitches are placed there. While applying traction to these stitches, a circumferential dissection is performed, trying to stay as close to the rectal wall but still preserving its full thickness. The dissection is performed along the lateral walls first, then continues to the anterior aspect until enough length is gained to move the rectum back to be placed within the limits of the sphincter without tension. A characteristic areolar tissue is reached once the anterior rectal wall is adequately separated from the urethra. The perineal body anterior to the center of the sphincter is reconstructed with long-term absorbable sutures up to the anterior limit. This is the space where the fistula had been. The rectum is anchored on its posterior aspect to the posterior edge of the muscle complex and an anoplasty is performed with 16 circumferential stitches. Even when the operation is rather minor, it requires meticulous technique. The operation is performed on an elective basis, but we prefer to do it before the baby is discharged home after birth. If a delayed repair is planned, it should be done within the first several months.
Two weeks after surgery, anal dilatations are started. These dilatations should be done at home following a strict protocol done twice per day. The size of the dilator must be increased every week by 1 mm of the diameter, until the size that is considered normal for the patient's age is reached. Figure 53-18 shows the size of the dilators to be used according to age. Once the correct size is reached, parents must continue doing dilatations twice per day until they feel that the dilator goes in very easily. At that point the frequency of these dilatations can be tapered according to a specific protocol (Fig. 53-19).
Size dilators according to age. (Reprinted from Levitt MA, Peña A. Imperforate anus and cloacal malformations. In: Ashcraft's Pediatric Surgery. 5th ed. 2010, with permission from Elsevier.)
Normal bowel control is expected for these patients. Constipation is very common and usually starts after breast feeding has been discontinued. This problem of constipation must be treated aggressively whereby the parents make sure that the baby empties his rectum every day.
PSARP for Rectourethral Fistula
A foley catheter is inserted through the urethra and the patient is then placed in a prone position with the pelvis elevated. After the skin is prepped, a midsagittal incision is made, from the lower portion of the sacrum to the area of the anal dimple. The skin is divided, as are the subcutaneous tissue, the parasagittal fibers, and the muscle complex (Fig. 53-20). The parasagittal fibers are split in the midline. The muscle complex runs perpendicular to the parasagittal fibers and extends from the skin up to the levator mechanism. The muscle complex joins the levator mechanism forming a nearly 90° angle. Together these muscles form the funnel-like muscle structure that surrounds the rectum. Deeper to the parasagittal fibers, one finds fat tissue that represents the ischiorectal fossa. Deep to this, one can identify the levator mechanism. The levator muscle is then divided in the midline. The distal colostogram predicts where the rectum will be during this approach (Fig. 53-21). If the patient has a rectobladderneck fistula, the distal rectum is high, at the peritoneal reflection and not visible from this approach. If the patient has a rectoprostatic fistula, the surgeon expects to find the rectum very high (1 cm below the coccyx), and if the distal colostogram shows that the patient has a rectourethral bulbar fistula, the surgeon will find the rectum very low in the incision (Fig. 53-22). Not having this vital information, the surgeon may explore deeper, looking for the rectum. If the patient has a rectobladderneck fistula, the surgeon will not find it, but may instead find the posterior urethra, bladderneck, seminal vesicles, vas deferens, an ectopic ureter, and/or the prostate. The surgeon will also risk damaging important nerves, which can lead to a neurogenic bladder.
Posterior sagittal incision. Division of parasagittal fibers and muscle complex. (Reprinted with permission from Peña A. Atlas of Surgical Management of Anorectal Malformations. New York: Springer-Verlag; 1990.)
Distal colostograms: A. Rectobulbar fistula. B. Rectoprostatic fistula. (Reprinted from Peña A. Imperforate anus. Surgery 1994;115(2), with permission from Elsevier.) C. Rectobladderneck fistula.
Exposure of the rectum. (Reprinted with permission from Peña A. Atlas of Surgical Management of Anorectal Malformations. New York: Springer-Verlag; 1990.)
Two silk sutures are placed in the posterior rectal wall, and the bowel is opened between both sutures. As the incision in the posterior rectal wall is extended distally and more silk sutures are placed anteriorly taking the bowel edge. The fistula is found at the most distal part. Once the fistula is visualized, a last 5-0 silk suture is placed at the edge of the rectal incision, taking part of the fistula orifice. Immediately above the fistula the anterior rectal wall is intimately attached to the posterior wall of the urethra. The separation of the rectum from the urinary tract represents the most delicate part of this procedure. For this, multiple 6-0 silk sutures are placed taking the rectal mucosa immediately above the fistula in a hemicircumferential fashion. These multiple sutures are used to exert uniform traction and to facilitate the separation of the rectum from the urinary tract. The initial part of the dissection is a submucosal one, and about 5 to 10 mm after that, it should become full thickness, separating the rectum completely from the urethra (Fig. 53-23). If this anterior rectal wall dissection is too deep, injury to other structures can easily occur. The rectum is surrounded posteriorly and laterally by a whitish fascia that must be divided before any attempt is made to mobilize the rectum. The circumferential dissection of the rectum after separation from the urinary tract should be performed, staying as close as possible to the rectal wall, but without injuring the wall itself. To do that, it is necessary to recognize that whitish fascia which has vessels that must be cauterized and divided. The rectum has an excellent intramural blood supply, and it is surprising how much length can be gained by dividing these vessels, while still preserving a good blood supply. Injuring the rectal wall, however, provokes damage to those important intramural vessels and may jeopardize the distal rectum. The stitches that were placed in the rectal edge during the opening of its posterior wall, as well as those silk stitches placed in the anterior rectal wall, are incorporated into a single mosquito clamp and are used to exert uniform traction to perform a circumferential dissection of the rectum to gain enough length to bring the rectum down to the perineum (Figs. 53-23 and 53-24). The dissection must continue until the rectum reaches the perineum without tension.
Separation of the rectum from the urinary tract. (Reprinted with permission from Peña A. Atlas of Surgical Management of Anorectal Malformations. New York: Springer-Verlag; 1990.)
Gaining rectal length and tapering the rectum when necessary. (Reprinted with permission from Peña A. Atlas of Surgical Management of Anorectal Malformations. New York: Springer-Verlag; 1990.)
At this point, the need for tapering of the rectum is evaluated (Fig. 53-24). The decision is based on the size of the rectum, as compared to the available space within the limits of the sphincter mechanism. If the rectum is too bulky and does not allow adequate sphincter reconstruction, tailoring of its posterior wall is indicated. In such cases, about 50% of the posterior portion of the rectum is resected and the posterior wall is reconstructed with interrupted long-term absorbable sutures. The amount and length of tapering must be individualized depending on the anatomy of the specific patient. This maneuver is rarely needed. It was more common when patients were operated on at later ages, with a diverted, blind rectum left untouched for a long period of time, which tended to dilate.
The anterior rectal wall is frequently thinned out as a consequence of the separation between rectum and urethra. It is advisable to reinforce this wall, bringing together the smooth muscle layer with interrupted 6-0 absorbable sutures. The urethral fistula is sutured with absorbable suture material. That silk suture placed at the fistula site helps to find and repair this area. The perineal body is reconstructed, bringing together the anterior limits of the sphincter previously determined by electric stimulation (Fig. 53-24). Finally, the rectum must be located in front of the levator and within the limits of the muscle complex (Fig. 53-25). The posterior edge of the levator muscle is sutured together. Then the posterior edge of the muscle complex is sutured together in the midline, taking a portion of the posterior rectal wall in order to anchor it (Fig. 53-26). The rest of the wound is closed and the anoplasty is created with 16 interrupted long-term absorbable sutures in a circumferential manner (Fig. 53-27). Since there is a colostomy, feeds are advanced rapidly and the patient can be discharged in 2 days. The Foley catheter is left in place for 7 days and is removed in an outpatient setting.
Placing the rectum with the limits of the sphincter. (Reprinted with permission from Peña A. Atlas of Surgical Management of Anorectal Malformations. New York: Springer-Verlag; 1990.)
Levator and muscle complex sutures. (Reprinted with permission from Peña A. Atlas of Surgical Management of Anorectal Malformations. New York: Springer-Verlag; 1990.)
Closure of incision and anoplasty. (Reprinted with permission from Peña A. Atlas of Surgical Management of Anorectal Malformations. New York: Springer-Verlag; 1990.)
PSARP and Laparoscopy or Laparotomy for Rectobladderneck Fistula
In this type of malformation, the rectum is found so high that it is not reachable through the posterior incision; thus, the patient needs a laparoscopic approach or laparotomy to mobilize the rectum. A total-body preparation that includes the entire lower part of the patient's body, including anterior, posterior, and lateral portions of the abdomen, as well as the pelvis and lower extremities in the sterile field, is done (Fig. 53-28). If the colostomy was placed in the proximal sigmoid and the distal rectum does not appear bulbous (and thus will not need tapering), we begin with laparoscopy. The distal rectum is dissected and the fistula ligated. In these very high defects, the rectobladderneck fistula is usually located 1 to 2 cm below the peritoneal reflection, and therefore, the pelvic dissection necessary to mobilize it is minimal. The ureters and vas deferens run very close to the rectum near the trigone of the bladder, and therefore the dissection of the rectosigmoid must be performed very close to the bowel wall. The rectum opens into the bladderneck in a T fashion. This means that there is no common wall above the fistula as seen in lower malformations. Once again the fistula is ligated; gaining adequate length of such a high rectum is very challenging and sometimes not possible laparoscopically. The legs are lifted up and a small perineal incision is made and the rectum is pulled down (Figs. 53-29 and 53-30). The rectum is tacked to the posterior edge of the muscle complex and the anoplasty is performed as previously described.
Total body preparation. (Reprinted with permission from Peña A. Atlas of Surgical Management of Anorectal Malformations. New York: Springer-Verlag; 1990.)
Rectal pull-through (Reprinted with permission from Peña A. Atlas of Surgical Management of Anorectal Malformations. New York: Springer-Verlag; 1990.)
Rectal pull-through. (Reprinted with permission from Peña A. Atlas of Surgical Management of Anorectal Malformations. New York: Springer-Verlag; 1990.)
Imperforate Anus Without Fistula
The technique used to repair an imperforate anus without fistula is very similar to the one described for rectourethral fistula cases. Even when there is no communication between the rectum and urethra, they still share a common wall. Therefore, a plane between both structures has to be established very carefully as previously described.
Patients who have rectal atresia can also be repaired through this approach. The distal rectum is exposed sagittally posteriorly. The anal canal is opened posteriorly making a circle into a hemicircle. The upper rectum is anastomosed to the anal skin preserving the anterior dentate line and the sphincter mechanism is reconstructed meticulously around the new anorectum.
The technique used for the repair of this defect is the same as the one described for the male counterpart. It is somewhat easier because the rectum is not intimately attached to the urethra. Care must be taken to separate the rectum from the posterior wall of the vagina.
Patients with this malformation have an excellent functional prognosis; thus, every effort should be made to avoid complications that may jeopardize the clinical result.
The patient is placed in the prone position with the pelvis elevated and multiple stitches are placed at the circumference of the fistula orifice (Fig. 53-31). In the case of a deep fistula the posterior sagittal incision is opened first so the fistula site is better visualized. These stitches allow for uniform traction in a caudad direction, which facilitates the separation of the rectum from the vagina. A short midsagittal incision is created, the sphincter mechanism divided, and the posterior rectal wall identified. The posterior and lateral walls of the rectum are identified first, which helps define the anterior wall dissection. The most delicate part of the operation is the separation of the rectum from the vagina. The two structures share a common wall without a plane of separation and, therefore, a significant degree of delicate and meticulous technique is required to achieve that separation without damaging either structure. The dissection between the rectum and the vagina must continue cephalad until both walls (vagina and rectum) are of full thickness and a characteristic areolar plane between them is seen (Fig. 53-32). Once the rectum has been mobilized sufficiently to reach the perineum without tension, the perineal body is repaired, bringing together the anterior limits of the sphincter mechanism previously determined electrically (Fig. 53-33). The levator mechanism is usually not exposed. The posterior edges of the muscle complex are then sutured together in the midline, taking part of the rectal wall as previously described. The wound is closed and the anoplasty is performed with 16 circumferential long-term absorbable sutures.
Sutures placed at the fistula site. (Reprinted with permission from Peña A. Atlas of Surgical Management of Anorectal Malformations. New York: Springer-Verlag; 1990.)
Separation of rectum from vagina. (Reprinted with permission from Peña A. Atlas of Surgical Management of Anorectal Malformations. New York: Springer-Verlag; 1990.)
Cloaca repair. Incision. (Reprinted with permission from Peña A. Atlas of Surgical Management of Anorectal Malformations. New York: Springer-Verlag; 1990.)
Because of this spectrum of defects, one can expect to find patients who are relatively straightforward to repair with excellent functional prognosis and others who represent an extraordinary technical challenge and may take many hours of delicate, meticulous technique, and sometimes the functional results may not be very good. This last group of malformations should be repaired by surgeons who have special expertise and experience in dealing with these complex malformations (Table 53-2). A separate endoscopy to define the anatomy outside the newborn period before embarking on the reconstruction is very helpful. A contrast cloacagram, which can be done in 3-D, is also very useful.
Table 53-2Two Types of Cloacas; our Primary Cloaca Experience, Excluding Redos |Favorite Table|Download (.pdf) Table 53-2 Two Types of Cloacas; our Primary Cloaca Experience, Excluding Redos
| ||Group A ||Group B |
|Common channel ||Short, <3 cm ||Long, >3 cm |
|Type of operation ||Only posterior sagittal ||Posterior sagittal and laparotomy |
|Length of procedure ||3 hours ||6–12 hours |
|Postoperative hospitalization ||48 hours ||Several days |
|Incidence in our series ||193 ||133 |
|Voluntary bowel movements ||66% (n = 93) ||34% (n = 59) |
|Voluntary urinary control ||73%b (n = 96) ||26% (n = 70) |
|Intraoperative decision making ||Relatively reproducible operation ||Complex and technically demandinga |
The operation starts with a long midsagittal incision extending from the middle portion of the sacrum through the anal dimple and continues down to reach the single perineal opening (Fig. 53-33). The entire sphincter mechanism is divided in the midline until a structure is found, which most of the time is the rectum. Sometimes, however, the anatomic arrangement is sufficiently complex, and the vagina is found posterior to the rectum. The anatomy should have been anticipated by a preoperative cloacagram. The posterior rectal wall is opened, and as the incision continues caudally, 5-0 silk sutures are placed, taking the edges of the open rectum to facilitate the exposure. The entire malformation is exposed. At this point, the length of the common channel is clearly seen. A Foley catheter is introduced into the urethra. The rectum is then separated from the vagina. For this, multiple 5-0 sutures are placed in the anterior rectal wall and the rectum is separated from the vagina, while the surgeon follows the same principles as described for the repair of rectovestibular fistula.
The total urogenital mobilization is then utilized. This consists in the mobilization of both vagina and urethra together as a unit without separating them (Fig. 53-34). For this, multiple silk sutures are placed taking the edge of the vagina and the common channel, in order to apply uniform traction on the urogenital sinus. The urogenital sinus is transected approximately 5 mm from the clitoris and a plane of dissection is created between the pubis and the anterior wall of the urogenital sinus. While applying superiorly directed traction to the multiple sutures, the suspensory ligaments of the urethra and bladderneck (which are avascular) are divided, which provides an immediate significant mobilization of the urogenital sinus (usually 2-3 cm). All cloacae with a common channel length of 2 to 3 cm can be repaired using this maneuver and without opening the abdomen. The advantages of this mobilization include preservation of an excellent blood supply to the vagina and urethra, an excellent cosmetic appearance, avoidance of urethrovaginal fistula, as well as vaginal strictures.
Total urogenital mobilization. A. The rectum has been mobilized posteriorly. B. After mobilizing the urogenital sinus, the vagina, and urethra are separated. (Reprinted from Peña A. Total urogenital mobilization. J Pediatr Surg 1997;32(2), with permission from Elsevier.)
For those patients who have longer common channels, the total urogenital mobilization through this approach may not be enough to reconstruct the malformation satisfactorily. The mobilized urogenital complex can be delivered up into the abdomen after a laparotomy. Sometimes dissection of its attachments this way allows for it to now reach the perineum. If this is not enough, then through the abdomen, separation of the vagina and urinary tract is performed, which is a tedious and meticulous part of the procedure. To do this, the bladder is first opened and the ureters catheterized, so that the surgeon can palpate them during the dissection of the common wall between vagina(s) and the bladderneck. After the vagina has been completely separated, the surgeon may find (a) that the vagina(s) reaches the perineum, which is rather unusual; or (b) that the patient has 2 hemivaginas located too high to reach the perineum. The transverse length of both hemivaginas together is longer than the vertical one. In that case, the surgeon can perform a maneuver called a vaginal switch. One of the hemiuteri, as well as the ipsilateral fallopian tube, is resected, preserving the ovary and its blood supply. The blood supply of the hemivagina of that side is sacrificed. The blood supply of the contralateral hemivagina is preserved and provides perfusion for both hemivaginas. The vaginal septum is resected and both hemivaginas are tubularized, creating a long single vagina. What used to be the dome of the hemivagina where the hemiuterus was resected is switched down to the perineum. This is an excellent maneuver but can be performed only when these anatomic characteristics are present (Fig. 53-35).
Vaginal switch. A. The right Fallopian tube is removed, preserving the ovary. The right hemi-vagina is mobilized. B. The right hemivagina is “switched down” to reach the perineum. (Reprinted from Peña A, et al. Surgical management of cloacal malformations. J Pediatr Surg 2004;39(3), with permission from Elsevier.)
Sometimes one finds a very high vagina(s) that is also very small; in those cases, one has to use a piece of bowel to augment or replace the vagina. One can use the colon or the small bowel. Given a choice, the colon sigmoid or the left colon has better characteristics to replace the vagina. The separated urethra is now tubularized and pulled through to the perineum.
A final variant is a long common channel (5 cm or more) and high vagina. In such a case one can leave the common channel untouched to become the neourethra, and separate the vagina(s) from the back of it through the abdomen. The vagina or vaginal replacement is then pulled through to the perineum.
The Foley catheter, after the repair of a cloaca, usually stays for approximately 14 to 21 days, and sometimes even longer in a reconstructed urethra. Vesicostomy may be needed particularly in long common channel cases, and the use of the urethra for intermittent catheterization is delayed until the child is older. Two weeks after the operation, the program of anal dilatations is started. The vagina is not subjected to dilatations.
The colostomy can be closed after the protocol of anal dilatations has been completed. At this setting the cloacal repair is endoscoped, and the assessment for the need and ease of intermittent catheterization is made.
Voluntary bowel movements are defined as the act of feeling the urge to use the toilet to have a bowel movement, the capacity to verbalize it, and hold the bowel movement until the patient reaches the bathroom. Soiling is defined as the involuntary leaking of small amounts of stool, which provokes smearing of the underwear. Constipation is defined as the incapacity to empty the rectum spontaneously (every day), which is sometimes manageable with changes in diet, and more often with laxatives. Fecal control is evaluated after the patient is 3 years of age.
Clinical results are different in each type of malformation described. A recent analysis of the authors' series showed that voluntary bowel movements were found in the following percentages: rectal atresia and perineal fistula (100%), vestibular fistula (93.8%), rectobulbar urethral fistula (87.5%), imperforate anus without fistula (85%), cloaca (83.3%), rectourethral prostatic fistula (76.5%), and rectobladderneck fistula (28.6%) (Table 53-3). Table 53-4 shows the percentage of patients who suffer from soiling for each defect. Soiling in patients who have voluntary bowel movements usually represents a manifestation of fecal impaction, and when the constipation is treated properly, the soiling will disappear. Patients who have voluntary bowel movements and never soil are considered “totally continent” (Table 53-5). This includes 100% of perineal fistula cases and 83.3% atresia or stenosis cases, 71.1% of vestibular fistulas, 70.6% of imperforate anus with no fistula, 32.1% of rectourethral bulbar fistulas, 27.3% of cloacae, 28.2% of rectoprostatic fistulas, and no patient in our series with rectobladderneck fistula.
Table 53-3Voluntary Bowel Movement and Type of Defect |Favorite Table|Download (.pdf) Table 53-3 Voluntary Bowel Movement and Type of Defect
| || ||Voluntary Bowel Movement |
|Defect ||No. of Cases ||No. ||% |
|Atresia or stenosis ||8 ||8 ||100 |
|Rectoperineal fistula ||52 ||50 ||96 |
|Rectovestibular fistula ||113 ||104 ||92 |
|Imperforate anus without fistula ||38 ||31 ||82 |
|Rectobulbar fistula ||97 ||77 ||79 |
|Cloaca, common channel <3 cm ||92 ||61 ||66 |
|Rectovaginal fistula ||5 ||3 ||60 |
|Rectoprostatic fistula ||94 ||61 ||34 |
|Cloaca, common channel >3 cm ||59 ||20 ||34 |
|Rectobladderneck fistula ||44 ||10 ||23 |
|Totals ||602 ||425 ||71 |
Table 53-4Soiling and Type of Defect |Favorite Table|Download (.pdf) Table 53-4 Soiling and Type of Defect
| || ||Soiling |
|Defect ||No. of Cases ||No. ||% |
|Rectoperineal fistula ||50 ||5 ||10 |
|Rectal atresia or stenosis ||7 ||1 ||14 |
|Recotvestibular fistula ||105 ||35 ||33 |
|Imperforate anus without fistula ||37 ||18 ||49 |
|Rectobulbar fistula ||91 ||46 ||51 |
|Cloaca, common channel <3 cm ||86 ||53 ||62 |
|Rectoprostatic fistula ||95 ||72 ||76 |
|Rectovaginal fistula ||5 ||4 ||80 |
|Cloaca, common channel >3 cm ||44 ||39 ||89 |
|Rectobladderneck fistula ||44 ||39 ||89 |
|Totals ||566 ||312 ||55 |
Table 53-5Totally Continent Patients and Type of Defect |Favorite Table|Download (.pdf) Table 53-5 Totally Continent Patients and Type of Defect
| || ||Totally Continent |
|Defect ||No. of Cases ||No. ||% |
|Rectoperineal fistula ||45 ||40 ||89 |
|Rectal atresia or stenosis ||7 ||6 ||86 |
|Rectovestibular fistula ||105 ||70 ||67 |
|Imperforate anus without fistula ||35 ||18 ||51 |
|Rectobulbar fistula ||87 ||39 ||45 |
|Cloaca, common channel <3 cm ||86 ||31 ||36 |
|Rectoprostatic fistula ||90 ||18 ||20 |
|Rectovaginal fistula ||5 ||1 ||20 |
|Cloaca, common channel >3 cm ||43 ||4 ||9 |
|Rectobladderneck fistula ||42 ||3 ||7 |
|Totals ||547 ||230 ||42 |
Constipation is a common sequelae seen after the repair of an anorectal malformation. Table 53-6 shows the percentage of patients who suffer from this. Interestingly, patients with lower defects and, therefore, with better prognosis for bowel control, have a higher incidence of constipation and vice versa. Constipation seems to correlate directly with the degree of rectosigmoid dilatation at the time of colostomy closure. Therefore, every effort should be made to try to keep the rectosigmoid empty and decompressed from day one in these patients. This is accomplished by proactive monitoring and laxative therapy starting right after the colostomy is closed, or soon after the repair if no colostomy is present.
Table 53-6Constipation and Type of Defect |Favorite Table|Download (.pdf) Table 53-6 Constipation and Type of Defect
| || ||Constipation |
|Defect ||No. of Cases ||No. ||% |
|Rectobladderneck fistula ||46 ||7 ||15 |
|Rectovaginal fistula ||5 ||1 ||20 |
|Cloaca, common channel >3 cm ||49 ||16 ||33 |
|Cloaca, common channel <3 cm ||91 ||36 ||40 |
|Rectoprostatic fistula ||96 ||44 ||46 |
|Imperforate anus without fistula ||39 ||20 ||51 |
|Rectovestibular fistula ||108 ||61 ||56 |
|Rectal atresia or stenosis ||7 ||4 ||57 |
|Rectoperineal fistula ||63 ||36 ||57 |
|Rectobulbar fistula ||96 ||59 ||61 |
|Totals ||600 ||284 ||47 |
Urinary control can be expected in the overwhelming majority of male patients after repair of the imperforate anus provided a good surgical technique was performed and there is no associated sacral or spinal anomaly. In cloacas where the common channel is shorter than 3 cm, approximately 20% of patients require intermittent catheterization to empty the bladder. The remaining 80% have voluntary urinary control. When the common channel is longer than 3 cm, approximately 80% of the patients require intermittent catheterization to empty the bladder. Fortunately, after the repair of a cloaca, patients almost always have a good bladder neck and they are capable of holding urine. The main functional disorder they suffer from is an incapacity to efficiently empty the bladder. Thus, when the bladder becomes completely full, the patients start having overflow urinary incontinence. Intermittent catheterization keeps these patients completely dry, and protects their kidneys from high bladder pressures.
Functional Sequelae and Their Management
The great majority of patients born with an imperforate anus who undergo a type of repair that includes the preservation of the original rectum (the vast majority these days) will suffer constipation. It seems to be the clinical manifestation of a hypomotility disorder of the rectosigmoid. Patients who at birth underwent transverse colostomies have a greater chance of having dilatation of the rectosigmoid and subsequently suffer from more constipation than patients with more distal colostomies. Patients with loop colostomies, particularly those who allow the passing of stool from the proximal to the distal bowel, will suffer from fecal impaction in the distal rectum, worse megarectosigmoid, and therefore, worse constipation. After the colostomy is closed, proper treatment of the constipation is imperative. Constipation is a self-perpetuating and self-aggravating condition; it produces megarectosigmoid, which, in turn, produces more constipation, creating a vicious cycle, ultimately leading to soiling (overflow pseudoincontinence). It is the surgeon's obligation to make the parents aware of these potential sequelae. The patients should receive a laxative type of diet and/or enough bowel-stimulating laxatives to produce emptying of the rectum every day. Even when the constipation is not curable, it is manageable.
Some patients with severe constipation come late, having never received treatment for constipation early in their lives, and they have a very severe megasigmoid and overflow pseudoincontinence. The laxative requirements in some of these patients is so high that it becomes impossible to administer the medication without producing vomiting. For this group of patients, and provided they have bowel control, an operation is indicated to resect the most dilated part of the colon (sigmoid resection) and create an anastomosis between the normal-size descending colon and the rectum (Fig. 53-36). By doing this, the amount of laxatives that these patients require may decrease, and sometimes, the need for them is eliminated. If a patient suffers from nonmanageable severe constipation and, in addition, belongs to the poor prognosis type of defect (fecal incontinence), then the treatment should consist of the administration of an enema every day; the sigmoid resection is contraindicated, unless the daily enema required to empty the colon is enormous. Usually the right daily enema keeps them clean. Sometimes a Malone appendicostomy and sigmoid resection (when the sigmoid is very dilated) can be done with antegrade enemas given thereafter.
Sigmoid resection. (Reprinted from Peña A. El-Behery M. Megasigmoid—a source of pseudoincontinence in children with repaired anorectal malformations. J Pediatr Surg 1993;28(2), with permission from Elsevier.)
Because of the high incidence of constipation in patients after an imperforate anus repair, some surgeons have thought to take rectal biopsies to rule out the presence of concurrent Hirschsprung disease. In our series, Hirschsprung is no more common in patients with anorectal malformation than in the general population. Constipation alone, even severe, without distention, enterocolitis, and failure to thrive is not Hirschsprung. Sadly some of these patients are subjected to a Hirschsprung-like pull-through. An abdomino-perineal pullthrough after an imperforate anus repair does fix the constipation, but they become totally incontinent, even when born with a benign defect because the induced hypermotility is too much for their suboptimal sphincters and anal canal to handle. Therefore, one must be careful to not overdiagnose this disease. A rectal biopsy occasionally may show absent ganglion cells after an imperforate anus repair but the biopsy was likely taken too low, in the transitional epithelium. Without confirmatory hypertrophic nerves, such a biopsy needs to be considered inadequate.
It is very important to establish an accurate diagnosis of the specific type of anorectal defect and the quality of the sacrum and spine early in life in order to try to predict the final functional prognosis in terms of bowel control. The parent's expectations can then be adjusted to the reality.
When patients are born with a good prognosis type of defect (rectal atresia, rectoperineal fistula, rectovestibular fistula, rectourethralbulbar fistula with a normal sacrum, imperforate anus without fistula with a normal sacrum), the patient can be expected to develop voluntary bowel movements by the age of 3 years. Soiling is usually avoided by adequately treating constipation. A small percentage of these patients, however, do not develop bowel control, and at around 3 years of age, they should have a bowel-management program to keep them artificially clean with a daily enema.
On the other hand, in patients who were born with a bad prognosis type of defect (rectobladderneck fistula, rectoprostatic fistula with an abnormal sacrum, cloaca with a common channel greater than 3 cm, and an abnormal sacrum), it is anticipated that they will not develop bowel control, and the family can be saved a lot of frustration, time, and expense trying to toilet train the child by directly starting a bowel-management program when the family decides that the child should go into normal underwear (usually at around 3-4 years of age).
With an accurate diagnosis and with knowledge of the status of the sacrum and the spine, it is possible to predict the final result. For those patients who have some chance of having bowel control, there are other prognostic signs that are valuable. For instance, the bowel-movement pattern in an infant frequently indicates the potential for bowel control. When a patient passes stool constantly without any evidence of feeling or pushing, it usually means that the patient is fecally incontinent, whereas a patient who has 1 to 3 bowel movements per day, even when involuntary, but remains completely clean between bowel movements and during the episodes of defecation shows some signs of feelings such as “pushing,” is frequently trainable. If a patient has a good bowel movement pattern such as this, the patient deserves a trial of toilet training, whereas a patient with a poor bowel-movement pattern benefits from the bowel-management program with a daily enema.
All patients born with an imperforate anus should at the age of potty training be completely clean of stool in the underwear either because they have bowel control (which happens in about 75% of all patients) or because they are subjected to a bowel-management program, a mechanical emptying of the colon.
Bowel management consists in teaching the parents how to clean the colon every day with the use of enemas. By keeping the patient's colon quiet for 24 hours, between enemas, they do not pass stool and thus avoid soiling. To achieve success with the bowel-management program, it is important to first learn which type of colonic motility the patient has; this can be inferred from a contrast enema study done with a hydrosoluble material.
Most patients who underwent a surgical repair that included the preservation of their original rectum will suffer from different degrees of megasigmoid. That means that they also suffer from constipation. Those patients will require large enemas, frequently a mixture of saline solution with added glycerin and/or soap, to be able to clean a large floppy colon. To keep the colon quiet in that group of patients is not a problem; one takes advantage of the fact that they are naturally constipated and, therefore, the patient stays clean 24 hours per day, between enemas.
A small group of patients undergo resection of their original rectum and/or sigmoid. These patients suffer from hypermotility of the colon and have a tendency to have diarrhea. In these patients, it is relatively easy to clean their colon (usually a saline only enema) because it is not dilated. The main problem, however, is trying to keep the colon quiet between enemas, and for that we use a constipating diet and/or medications, such as loperamide and pectin, and fiber additives to slow down the colonic motility.
The bowel-management program is implemented by trial and error. Every patient needs a different type of enema. It usually takes approximately 1 week to implement a working system. To assess whether the enema successfully cleans the colon, we use a daily x-ray film of the abdomen.
As previously mentioned, urinary incontinence occurs as an overflow phenomenon in 80% of patients who were born with a cloaca with a common channel longer than 3 cm and in 20% of patients with a shorter common channel. Because the bladderneck is usually competent, intermittent catheterization usually keeps these patients dry.
Urinary incontinence in male patients after an imperforate anus repair may occur because of a poor surgical technique and some sort of nerve damage, or occurs in a patient with an associated sacral or spinal problem.