Cloacal Exstrophy

Pediatric Surgery
Discussion between Dr. Alberto Pena and Dr. Todd Ponsky about cloaca exstrophy

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Podcast Discussion:

What is cloacal exstrophy?

  • A group of congenital diseases involving the lower gastrointestinal tract, urogenital tract, spine, and even the lower extremities. Patients may often be born with omphalocele
  • There may be bladder exstrophy. Female patients may have two hemi-vaginas and hemi-uteruses, and male patients may have two hemi-phalluses. Gonads are usually normal. There may be kidney problems, but they tend to be normal.
  • Exposed GI mucosa tends to involve the cecum. There may also be ileo-cecal intussusception.
  • Intra-abdominal findings include a shortened or absent colon. There may be duplication of the cecum or appendix. Most commonly found is a small pouch of colon with abnormal blood supply.
  • Spinal abnormalities can include tethered cord or myelomeningocele, which can affect the motion of the lower extremities.
  • Patients may be born without omphalocele, but can still have all of the above abnormalities, albeit intraabdominally.
Gender Assignment

  • Gender assignment remains controversial; however, it remains extremely difficult to create a function phallus in a patient born with hemi-phalluses.
  • Historically, male patients born with hemi-phalluses underwent bilateral orchiectomy, removal of the hemi-phalluses, and creation of a neo-vagina (typically from small bowel). They were also administered exogenous female hormones. These patients were reared as females. However, they tended to develop male attitudes and behaviors and many of these patients became resentful of their gender re-assignment as adults.
  • Now, patients who are born with XY chromosomes are raised as males. Creation of a better phallus for patients with hemi-phallus is an active area of research.

Management of cloacal extrophy

  • Multidisciplinary approach is paramount.
  • No significant improvements in the ultimate functional status of patients (serious limitations in bowel and urinary control, as well as sexual function and spinal abnormalities).

Role of the pediatric general surgeon in cloacal exstrophy

  •  The three major elements of repair are:
    • Closure of the omphalocele (although this is not always possible)
    • Differentiation, and subsequent separation, of urothelium from intestinal mucosa. This allows the urologist to approximate the edges of urothelium in an attempt to close the bladder.
    • End colostomy creation
Failure to create a real End Colostomy and Rescue Operation

  • The pediatric general surgeon must be prepared to encounter very bizarre anatomy. However, he must nonetheless differentiate proximal from distal colon, with subsequent creation of an end colostomy. A common, yet very serious, error is creation of an end ileostomy. This leaves the colon in discontinuity and attached to the urinary tract. Consequences of this include large ileostomy losses and absorption of urine via the colon (which can cause acidosis and subsequent retardation of growth and development). The defunctionalized colon will also not grow.
  • For patients who have undergone end ileostomy and have been referred to the Cincinnati Children’s Hospital, a "rescue” operation has been created in order to reclaim the previously unused colonic gastrointestinal mucosa.
  • Rescue entails ileostomy takedown with re-anastomosis, location of colonic tissue with separation of colonic from urogenital tissue, and creation of end colostomy.

Pubic Separation and Pelvic Osteotomies

  • The separation of the pubic bones in bladder exstrophy is not as severe as in cloacal exstrophy. It is very difficult to properly correct the pubic bone separation.
  • It is not always necessary to perform Pelvic osteotomies during the initial operation.
  • Due to orthopedic problems, patients with cloacal exstrophy will be patients for life. These patients tend to have persistent separation of the pubic bones. This alters the gait, which may be a significant source of concern for some patients. Other patients may have severe spinal problems, including tethered cord.
Colonic Dysmotility and Bowel Management

  • The end colostomy may have poor motility, for unknown reasons. Under these circumstances, the children may develop bacterial overgrowth, similar to Hirschsprung’s enterocolitis. These patients require irrigation via the stoma.
  • Around 3 years of age, when these patients are getting ready for school, decisions must be made regarding stoma takedown and urinary continence. These patients have small bladders and will require bladder augmentation. This is typically performed using gastrointestinal tract.
  • To determine if the patient will be a good candidate for pull-through, a bowel management through stoma program should be used. This involves administration of enemas through the end colostomy.
  • If the patient has no colon whatsoever, they will have a stoma for life. The ileum should not be attempted to be pulled down to the perineum, as there will be lifelong incontinence. Only patients who can form solid stool are eligible for pull-through and only patients with adequate colon can form solid stools. During all pediatric surgical operations, all attempts should be made to include and preserve the maximum amount of colon.
  • The pediatric surgeon’s job is complete if the patient is to have a lifelong stoma.

Surgical planning and technique

  • Urologic and general surgery operations are typically performed together. The general surgery portion is first. The end colostomy is taken down and the colon pulled down to the pelvis. This may be performed with an appendicostomy (Malone procedure) in order to administer antegrade enemas. Typically, small bowel, and/or stomach is used for bladder augmentation. The colon is typically not used in order to aid in preservation of solid stools.
  • The patient is placed supine, usually in the frog leg position. There is no need for prone positioning. A midline abdominal incision is performed in order to preserve the flanks and lower quadrants for potential future stoma creation. Dense adhesions are to be anticipated. The stoma is taken down circumferentially from the abdominal wall. The space posterior to the bladder is created. Next, the colon is mobilized in order for the distal colon to be brought into the vessel. Some ligation of blood vessels is usually required, and again it should be noted that there is significant variation in vascular supply to the colon in patients with cloacal exstrophy.

Vaginal and Urologic Issues in Cloacal Exstrophy

  • In patients born with two hemi-vaginas, there is a wide spectrum of disease. In less severe cases, the intervaginal septum may be simply removed. Other patients may have two distinct vaginas and removal of one of the vaginas is elected. Typically, the vagina with the more normal-appearing cervix is preserved. This operation is performed at the time of colonic pull-through. These patients may become pregnant, but they have very high risk pregnancies. There is a high rate of miscarriage and premature labor and Caesarean section is recommended. Pregnancy is typically not advised.
  • A Mitroffanoff procedure may be required for intermittent bladder drainage.
  • Even as adults, these patients should follow up with pediatric surgeons.

The Pull-Thru Network

  • The Pull-Thru Network is a national organization of parents and children to support those born with anorectal malformations. Per their website, "Information, education, support and advocacy for families, children, teens and adults who are living with the challenges of congenital anorectal, colorectal or urogenital disorders.”

Summary

  • Initial operation (neonatal period)
    • Close (or attempt to close) omphalocele
    • Separate bowel from urinary tract
    • Create end colostomy
    • Close (or attempt to close) bladder
    • Osteotomy and attempted approximation of pubis bones
  • Subsequent operation (3 years of age)
    • Colostomy closure
    • Colon pull-through
    • Bladder augmentation
    • Vaginal reconstruction
    • Possible Malone and Mitrofanoff procedures

Prenatal diagnosis

  • Imaging technology is improving, aiding in prenatal detection. More complex anorectal disease are actually easier to diagnose prenatally, as they tend to have less subtle findings and more associated defects.

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