24 Complications after the Treatment of Anorectal Malformations and Redo Operations

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24.1 Introduction

In spite of the technical advances in the surgical repair of anorectal malformations (ARM) that have occurred over the last 20 years, complications that require a secondary procedure are still common.

Surprisingly, this need is not isolated to the group of patients with very complex malformations. Instead, it spans the entire spectrum of malformations seen, and in fact is quite common for the relatively benign malformations.

Reoperative surgery may be considered for several reasons (see Chap. 25). Fecal incontinence may be present after the first operation, and a surgeon may wish to attempt to improve on the results. Other patients may have suffered significant, sometimes cata- strophic complications because of technical errors and require revisional surgery to alleviate pain, dis-

comfort, and other sequelae. Finally, mismanagement of constipation can lead to significant sequelae.

It is clear that a patient’s best chance for a good functional result is when the proper operation is performed during the first definitive procedure and complications are avoided [1]. This is especially true in those patients born with a defect that has a good prognosis. It is unfortunate when such patients end up with fecal or urinary incontinence as a result of avoidable complications of the surgical repair.

Complications in patients who have undergone surgical repair of an ARM can be grouped into three categories: (A) those with fecal incontinence requiring a reoperation, (B) those who have suffered a perioperative complication, and (C) those suffering from sequelae resulting from constipation (Table 24.1) [2].

24 Complications after the Treatment of Anorectal Malformations and Redo Operations

Marc A. Levitt and Alberto Peña

Contents

24.1 Introduction . . . 319

24.1.1 Group A, Patients with Fecal Incontinence Requiring Reoperation . . . 320

24.1.2 Group B, Perioperative Complications . . . 320 24.1.2.1 Wound Infection . . . 320

24.1.2.2 Femoral Nerve Palsy . . . 321 24.1.2.3 Rectal Problems . . . 321

24.1.2.4 Rectourinary and Rectovaginal Fistulae . . . 321 24.1.2.5 Persistent Urogenital Sinus . . . 322

24.1.2.6 Acquired Vaginal Atresia . . . 322 24.1.2.7 Acquired Urethral Atresia . . . 322 24.1.2.8 Posterior Urethral Diverticulum . . . 323 24.1.2.9 Other Urologic Injuries . . . 323 24.1.2.10 Neurogenic Bladder . . . 323

24.1.2.11 Complications Specific to the Laparoscopic Approach to ARM . . . 324

24.1.2.12 Rectal Prolapse . . . 324

24.1.3 Group C, Sequelae of Constipation . . . 324 24.2 Conclusion . . . 325

References . . . 325 Table 24.1 Complications associated with anorectal malfor- mations

Group A Patients with fecal incontinence requiring reoperation

Group B Perioperative complications

• Wound infection

• Femoral nerve palsy

• Rectal problems: dehiscence, retraction, infection and/or acquired atresia

• Rectourinary fistula

• Rectovaginal fistula

• Persistent urogenital sinus

• Acquired vaginal atresia

• Acquired urethral atresia

• Posterior urethral diverticulum

• Urologic injuries

• Neurogenic bladder

• Complications involving the laparoscopic approach

• Rectal prolapse

Group C Complications from mismanagement of constipation

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24.1.1 Group A, Patients with Fecal

Incontinence Requiring Reoperation Reoperation to improve a patient’s functional prognosis is indicated in several circumstances. During the first 5 years of our experience, reoperative surgery was performed on every patient we evaluated who underwent a repair at another institution and suffered from fecal incontinence. During those years, we hoped that the new posterior sagittal approach would give these patients an opportunity to recover bowel control. When the results were evaluated [3,4], only 30% of those patients experienced a significant improvement. Therefore, the indications for surgery were modified.

At the present time, reoperation for fecal incontinence is recommended only for patients with very special criteria. Those born with a malformation associated with a goog prognosis, with a rectum that is completely mislocated, with an intact rectosigmoid, a normal sacrum, and an intact sphincter mechansim are candidates. The rectal location can be evaluated by magnetic resonance imaging if its mislocation is not obvious by inspection.

For these reoperations, the rectum is approached posteriorly. Multiple silk stitches are placed at the mu- cocutaneous margin in order to apply uniform traction to facilitate the dissection and mobilization of the rectum. A full rectal dissection and mobilization is performed, staying as close as possible to the bowel wall but avoiding injury. The limits of the sphincters, including the parasagittal fibers, muscle complex, and levator muscle, are determined by electrical stimula- tion and the rectum is repositioned within it.

In many cases, the patient is found to have had the colon, and not the rectum pulled down, which is identified by the presence of mesentery attached to the bowel. In such cases, the mesenteric fat must be trimmed from the last few centimeters of the rectum to allow for direct contact between the sphincter mechanism and the colonic wall. An anoplasty performed within the limits of the sphincter mechanism completes the reconstruction.

The number of patients that require a reoperation for fecal incontinence has decreased significantly over the years. This is probably due to the increased use of the posterior sagittal approach, which provides supe- rior exposure and prevents the complete mislocation of the rectum that was seen with other techniques.

Years ago many patients underwent abdominal perineal pull-through procedures with endorectal dissections of the rectosigmoid [5]. This procedure

essentially resulted in loss of the rectosigmoid. These patients do not suffer from constipation. Instead they suffer from increased colonic motility and a tendency to diarrhea. It took several years to recognize this specific group of patients, and today revisional surgery is not offered to them, because it is clear that they never regain bowel control. Fortunately, endorectal pull- throughs are no longer performed for ARM and it is rather unusual to see these patients.

In addition to the aforementioned group, those patients born with poor prognosis defects and fecal incontinence are also considered inappropriate candidates for reoperation. These patients typically have an abnormal sacrum, flat perineum, and poor sphincters. There is usually evidence that they were born with a high rectoprostatic or rectobladderfistula, or a cloaca with a common channel longer than 3 cm.

Their sacral ratio is almost always less than 0.4. We do not reoperate on these patients, even if they have a completely mislocated rectum because they do not improve after reoperation. Instead they are offered a bowel management program [6] in order to prevent soiling and to keep them completely clean (see Chaps. 29 and 30).

When revisional surgery for fecal incontinence is offered, the likelihood of the patient regaining bowel control is reviewed with the family. Even with those patients who are expected to improve, the bowel management program is implemented prior to surgery. If it turns out that the patient does not improve enough after reoperation to avoid enemas, the already tested bowel management is reinstituted.

24.1.2 Group B, Perioperative Complications Group B includes those who sustained a perioperative complication during or shortly after the first operation [2]. The specific types of complication are described below.

24.1.2.1 Wound Infection

Wound infection of the posterior sagittal incision is very uncommon in the immediate postoperative period, but is more prevalent in the presence of a loop colostomy, which might not be completely diverting, or in cases operated without a colostomy. Fortunately, the infections usually affect only the skin and subcu- taneous tissue and heal secondarily, without functional sequelae.

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24.1.2.2 Femoral Nerve Palsy

Transient femoral nerve palsy can be observed, particularly in adolescent patients, and is a consequence of excessive pressure in the groin during the PSARP operation. This problem can be avoided by adequate cushioning of the patient’s groin area.

24.1.2.3 Rectal Problems

Patients can experience dehiscence, retraction, infection and/or acquired atresia of the rectum related to technical problems arising during the pull-through procedure. These are usually the result of excessive tension or inadequate blood supply. In addition, anal strictures may result when families do not follow the prescribed protocol of dilatations.

Reoperation for these patients proceeds posterior sagittally. In cases of retraction, dehiscence, and acquired atresia, the rectum is usually located some- where high in the pelvis and is surrounded by a significant amount of fibrosis. Multiple 6-0 silk sutures are placed in the rectal wall in order to exert uniform traction and facilitate a circumferential dissection of the rectum, again trying to stay as close as possible to the rectal wall without injuring it. Bands and extrinsic vessels surrounding the rectum are divided and cau- terized circumferentially until enough rectal length is gained so as to place the rectum within the limits of the sphincter mechanism.

Short ring-like rectal strictures can be treated with a Heineke-Mikulicz type of plasty. Strictures that are longer than 1 cm must be resected, with the rectum mobilized until the fibrotic portion can be removed, and a fresh nonscarred portion of rectum pulled down, creating a new anus.

Based on our anatomic findings during these reoperations, we speculate that retraction, dehiscence, and acquired rectal atresia were most likely due to a poor technique used to mobilize the rectum. During a primary procedure, the rectum, when seen posterior sagittally, is covered by a very characteristic white fascia that contains vessels to the rectum. The surgeon must dissect this fascia off the rectum, remaining as close as possible to the rectal wall. Uniform traction provided by multiple silk sutures is imperative to facilitate the dissection. Bands and the extrinsic rectal blood supply must be divided to gain rectal length.

The intramural blood supply of the rectum is excel- lent; and the rectum can be dissected to gain significant length provided the rectal wall is not injured. The

most likely cause for difficulty in dissection of the rectum is working outside the fascia. Alternatively, dissection too close to the rectum can injure the rectal wall, interfere with the intramural blood supply, and provoke ischemia. The result of all this is an incom- plete mobilization, rectal ischemia, and a rectal-to- skin anastomosis under tension, which may explain most of these complications.

We speculate that rectal strictures are also most likely due to ischemia of the distal part of the rectum. When the rectum is correctly mobilized and the blood supply kept intact, it is extremely unlikely to see an anal stricture. A few patients of ours who were operated on primarily failed to follow our protocol of dilatations and returned months after their operation with strictures. These patients had a thin fibrotic ring in the area of the anoplasty, which was easy to treat either with an anoplasty or dilatations. A long narrow stricture is most likely due to rectal ischemia.

Some surgeons do not have their patients follow a protocol of anal dilatations. In order to avoid painful maneuvers to the patient, they follow a specific plan consisting of taking the patient to the operating room every week and under anesthesia performing forceful dilatations. Those dilatations can actually provoke lacerations in the anal verge, which then heal with scarring, only to be reopened during the next forceful dilatation, leading ultimately to an intractable ring of fibrosis.

24.1.2.4 Rectourinary and Rectovaginal Fistulae Patients may have various types of rectogenitourinary tract fistula complications. Fistulae can be persistent when the original rectourethral fistula remains untouched during the main repair, even when the rectum was repaired. Recurrent fistulae may occur if the surgeon repaired the fistula but it reopened. Acquired rectourethral fistulae are those that are inadvertently created during the repair of a malformation [7].

Acquired rectovaginal fistulae can occur during a failed attempt at repair of a rectovestibular fistula. In the past urethra-vaginal fistula was the most common and feared complication in cases of persistent cloaca prior to the introduction of the total urogenital mobilization maneuver [8]. In certain circumstances, the vagina can be rotated to try to prevent this complication [9], but even with that maneuver, these fistulae can occur.

Persistent rectourethral fistulae can occur in patients who were born with a rectourethral bulbar fis-

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tula and underwent a repair that did not address the fistula. We speculate that surgeons following the old diagnostic approach performed an invertogram and found the bubble of rectal air close to the skin. This may have led to an approach through the perineum, with identification of the rectum and subsequent pull-through and anoplasty. Since the surgeon was completely unaware of the low rectourethral bulbar fistula, it was not repaired.

Recurrent rectourethral fistulae may result if the fistula is closed, but the rectum is not mobilized adequately, leaving the anterior wall under tension. A dehiscence of the anterior rectal wall may explain the recurrence of the fistula. Also, leaving sutures in the rectum adjacent to the sutures in the urethra may lead to the formation of a recurrent fistula. Consequently, an injured rectum that requires a repair to the anterior wall may lead to the development of a recurrent fistula. The same explanation may apply to rectovaginal fistulae.

Acquired rectourethral fistulae can occur in male patients who were born with rectoperineal fistulae if they undergo their first operation without a Foley catheter in the urethra. During the mobilization of the anterior wall of the rectum, an unrecognized urethral injury can occur and, if not mobilized to leave normal rectal wall in front of the urethral injury, an acquired rectourethral fistula will form.

Fistulous complications can be approached posterior sagittally. The posterior rectal wall should be opened and the fistulae identified and closed. The rectum then needs to be separated from the urinary tract or the vagina, and mobilized as so as to be sure that a completely normal anterior rectal wall is left in front of the urethral or vaginal suture line.

24.1.2.5 Persistent Urogenital Sinus

This problem occurs in patients born with a cloaca who underwent an operation in which the rectal component of the malformation was repaired, but the urogenital sinus was ignored (Fig. 24.1). Their reoperation can also be approached posterior sagittally. The rectum must be completely dissected and reflected out of the way. This allows exposure of the urogenital sinus, which can be repaired using the same technique that is employed during the treatment of a cloaca [8,9].

All of the patients in one of our reports came to us with an original diagnosis of “rectovaginal fistula”

[10]. The word cloaca was never mentioned in the operative report. Only the rectal component of the mal-

formation was repaired and the urogenital sinus was left unattended. In our experience, a true congenital rectovaginal fistula is an extremely unusual defect [1], yet in the literature from previous years, we have found frequent mention of this malformation and very little reference to cloacas [11–17]. In the recent literature, there is an increase in the diagnosis of cloacas and less mention of rectovaginal fistulae, which, we think, reflects the improved understanding of the true anatomy of these lesions [18–21].

24.1.2.6 Acquired Vaginal Atresia

Complete fibrosis of the vagina can occur as a result of excessive dissection in an attempt to mobilize a high vagina, during a failed attempt to repair a cloaca. This comlication requires a reoperation and sometimes a vaginal replacement. It usually occurs when the vagina is separated from the urethra during the repair of cloacas. Such maneuvers are rarely used since the advent of total urogenital mobilization [8]. The sepa- ration of the vagina from the urinary tract is not an easy maneuver; the vagina may become devascular- ized and as a consequence, patients develop ischemic vaginal atresia. Those patients with acquired vaginal atresia are treated using the same surgical approach as for persistent urogenital sinus.

24.1.2.7 Acquired Urethral Atresia

Acquired urethral atresia in cloaca patients can occur as a result of devascularization of the pulled-through

Fig. 24.1 Pull-through only of the rectum in a patient with a cloacal malformation, leaving the urogenital sinus untouched ([27], with permission)

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or reconstructed neourethra. In male patients, it has occurred when the urethra was accidentally tran- sected during an attempt to repair an anorectal malformation. This complication mostly occured when the surgeon approached a patient posterior sagitally without a pre-operative high pressure distal colostogram. To repair this problem the rectum must be mobilized in order to expose the urethral area. Both urethral ends need to be identified, dissected, and mobilized enough to perform a tension-free end-to- end anastomosis.

24.1.2.8 Posterior Urethral Diverticulum

This complication can occur when a retained portion of the rectum is left attached to the posterior urethra (Fig. 24.2). The same reoperative approach to fix it can be utilized, with a posterior sagittal incision, mobilization of the rectum to expose the posterior aspect of the urinary tract, identification of the diverticulum, and dissection of it down to the urethra. The diverticulum can be separated from the urethra in the same manner as in a primary repair of ARM, with the urethra closed and the diverticulum resected.

This complication occurs in patients born with a rectourethral bulbar fistula that was repaired transab- dominally. It is easy to understand that the surgeon was unable to reach the fistula site through the ab- domen. Consequently, the rectum was amputated, leaving a piece of rectum attached to the urethra. This potential complication is possible with a laparoscopic approach, particularly if the rectum reaches well below the peritoneal reflection.

These patients, are initially asymptomatic, but after years develop symptoms such as passage of mucus through the urethra, dribbling, orchioepididimitis, urinary tract infections, and urinary pseudoincontinence. In addition, we saw one such patient who, after 30 years, developed an adenocarcinoma in the piece of rectum left attached to the urethra.

24.1.2.9 Other Urologic Injuries

Significant urologic injuries such as transection of the bladder neck, transection of the urethra, and injury to the vas deferens, seminal vesicles, prostate, and ectopic ureters have occurred, usually when the posterior sagittal approach was performed without a good previous distal colostogram, and thus the precise anatomy was not known prior to the posterior sagittal dissection [7].

24.1.2.10 Neurogenic Bladder

Neurogenic bladder in male patients with ARM is extremely unusual. In our series, we have only seen it in patients with a very abnormal sacrum or associated spinal anomalies. If it does occur, it mostly likely represents a denervation of the bladder and bladder neck during the repair. It is very important to note that patients with cloacal malformations are different with regard to this subject. Patients with cloaca often have a deficient emptying mechanism of the bladder.

They do not have the typical “Christmas tree” type of image of a neurogenic bladder seen in patients with a spina bifida. They have rather a flaccid, smooth, large bladder that does not empty completely. Fortunately, most patients with cloacas have a very good bladder neck. The combination of a good bladder neck with a floppy, flaccid bladder, make these patients ideal candidates for intermittent catheterization, which keeps them completely dry.

Two exceptions to this rule exist. One is represented by patients who have a very long common channel, in which the hemivaginas as well as the rectum are attached to the bladder neck and after these are separated the patients are left with no bladder neck or a very damaged bladder neck. The second group is represented by a small number of cloaca patients who are born with separated pubic bones, who could be described as having a covered exstrophy [22]. These patients have no bladder neck congenitally and they eventually require a continent diversion type of operation.

Fig. 24.2 Posterior urethral diverticulum, representing the un- dissected former distal rectum ([27], with permission)

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24.1.2.11 Complications Specific to the Laparoscopic Approach to ARM

Long-term results and complications have not yet been described for the laparoscopic approach to imperforate anus, which is a relatively new approach that was developed to avoid a laparotomy and to minimize the posterior sagittal incision [23]. We have managed several complications with this approach, and can an- ticipate others.

Avoidance of the exposure required to perform the posterior sagittal approach can lead to inadvertent injuries, such as injury to the bladder neck, urethra, or an ectopic ureter. Precise understanding of the anatomic relationships between the pelvis and the laparoscopic view is vital to avoid these problems. Like the transabdominal approach, there is potential for leaving behind the distal rectal cuff, leading to a posterior urethral diverticulum, particularly for malformations below the peritoneal reflection, such as rectobulbar fistula. Finally, to avoid rectal prolapse, a pelvic hitch is employed; if this step is omitted or done incorrectly, the incidence of prolapse will probably be significant.

With the avoidance of the posterior sagittal incision, the described laparoscopic operation omits several key steps of the PSARP that are very important to avoid prolapse [24], particularly tacking of the posterior rectal wall to the muscle complex.

24.1.2.12 Rectal Prolapse

Rectal mucosal prolapse occurs following PSARP, with an incidence of 3% [24]. It is more common in patients with higher malformations and with poor sacral and pelvic musculature. Significant prolapse may lead to ulceration, bleeding, and mucus produc- tion, and can interfere with anal canal sensation and thus impact upon a patient’s functional prognosis.

Correction of the prolapse can be performed transa- nally, with mobilization of the redundant full-thick- ness rectum, and redo-anoplasty. This is ideally done prior to colostomy closure. Sometimes, however, prolapse only develops after colostomy closure and in the presence of constipation [24]. The repair of the prolapse in patients without a colostomy requires a strict preoperative bowel preparation, insertion of a central line, nothing by mouth for 7 days, and administration of parenteral nutrition.

24.1.3 Group C, Sequelae of Constipation Group C includes those patients referred to our institution because of fecal incontinence who actually had untreated severe constipation, chronic impaction, and therefore suffered from overflow pseudoincontinence.

All of these patients have several factors in common.

All were born with a malformation with good functional prognosis and underwent a technically correct, successful operation. Postoperatively, they all had severe constipation which was not adequately treated and developed megasigmoid and chronic fecal impaction. Adequate treatment of their constipation, with or without a sigmoid resection [25], rendered them fecally continent (see Chaps. 29, 30 and 32].

Constipation is the most common functional dis- order observed in patients who undergo posterior sagittal anorectoplasty [1]. Interestingly the incidence of constipation is inversely related to the frequency of voluntary bowel movements. This means that patients with the best prognosis for bowel control have the highest incidence of constipation. Patients with very poor prognosis, such as bladder neck fistula, have a rather low incidence of constipation.

It seems from analysis of our series that constipation is related to the degree of preoperative rectal ectasia. Colostomies that do not allow cleaning and irrigation of the distal colon lead to megarectum.

Transverse colostomies lead to a micro left colon with dilatation of the rectosigmoid. Loop colostomies allow for passage of stool and distal fecal impaction. It is clear that keeping the distal rectosigmoid empty and not distended from the time the colostomy is es- tablished and proceeding with pull-through and subsequent colostomy closure as early as possible within several months results in better ultimate bowel func- tion [26].

All patients in this pseudoincontinent group underwent a laxative test to determine whether they were fecally continent. First, large-volume enemas were administered until the patient’s colon was clean (disimpacted). Daily laxatives were then administered, increasing the amount each day until the amount necessary to produce colonic evacuation was determined. A plain abdominal x-ray was obtained every day to assess the colonic emptying (see Chaps. 29, 30 and 32). If the patient demonstrated the capacity to feel the stool in the rectum, reach the bathroom, have voluntary bowel movements, and remain clean every day, the patient was considered continent. The patient was then offered the option of continuing the treatment with large quantities of laxative for an indefinite period of time or a sigmoid resection [25] in order to

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make the constipation more manageable and thereby decreasing the laxative requirement.

It is extremely important to recognize this group of patients. Some may be wrongly diagnosed as suffering from true fecal incontinence and some have even undergone reoperations such as gracilis muscle or arti- ficial sphincters, which can actually make the patient worse. This problem should be suspected when one sees a patient who was born with a benign malformation, who underwent a technically correct operation, but who was not treated correctly for constipation.

24.2 Conclusion

Unfortunately, despite great advances in pediatric surgical care, there remain a significant number of patients who undergo attempted anorectal repairs with significant complications, many of which are preventable. One must have a thorough understanding of these malformations, utilize a meticulous technique, and employ rigorous, careful postoperative management if repairs are to be successful. These basic fun- damentals need to be emphasized in the training of young pediatric surgeons, so as to improve the out- look for children born with ARM.

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