The first reports of Hirschsprung disease date back to the 17th century, but treatment, workup, management, including operative surgical approach has changed dramatically since the 1940s. So whether you're team Swenson or Suave, today we're going to break down Hirschsprung disease with a couple experts. Hi, I'm Jason Frischer. He's the director of the colorectal center at Cincinnati Children's Hospital Medical Center. Today we're going to review Hirschsprung disease. Hirschsprung disease is a congenital anomaly of the GI tract that results in a functional bowel obstruction. And that's Dr. Aaron Garrison, a pediatric colorectal surgeon at Cincinnati Children's Hospital Medical Center. The ganglion cells don't make it all the way down distally. The colon ends up not being able to contract. So how does Hirschsprung disease typically present? More than 95% of neonates pass meconium within the first 48 hours of life. And failure to pass meconium is typical of Hirschsprung's disease. If an infant who has not passed meconium in the first 48 hours of life presents to your clinic, the possibility of Hirschsprung's disease should be entertained. How common is Hirschsprung disease? So Hirschsprung disease is actually relatively common in a busy children's hospital. It's got an incidence of about 1 in 5,000 children. Are there any familial associations or risk factors? Unfortunately, about 10% of children will have a positive family history and means there is some predisposing genetic conditions such as the RET gene that can go along with that. As many of you know, Hirschsprung's disease is associated with trisomy 21 and up to 10% of children with Hirschsprung's disease will have trisomy 21, but only 1 to 2% of patients with trisomy 21 have Hirschsprung's disease. There are a few other syndromes that are associated with Hirschsprung's disease, including Wordenberg syndrome, congenital central hyperventilation, which is known as Andine's curse, and some others. How do you work up Hirschsprung's disease? The three studies that should be considered for evaluating for Hirschsprung's disease include contrast enema, rectal biopsy, and possibly anorectal manometry. We typically use a water-soluble contrast enema. Alright, so what are you looking for on that enema? The classic finding is a transition zone in the rectosigmoid, but that transition zone really can be located anywhere within the bowel. Hold on a second. What does he mean when he says transition zone? Well remember when Dr. Garrison explained that the nerve cells don't migrate down to the distal part of the rectum? Well, when that happens, it's contracted. And when there's normal nerve cells, it's not contracted. So the transition zone is from contracted rectum and all of a sudden it opens up into dilated rectum. That's the transition zone. Other findings suggestive of Hirschsprung's disease include a rectosigmoid ratio of less than 1.0. A rectosigmoid ratio less than 1? Yes. Just like when you're holding a water balloon and the most distal part is the most dilated, the rectum is usually more dilated than the proximal colon. And in Hirschsprung's disease, the inverse is true, and the rectosigmoid ratio is actually less than 1. Also the inability to evacuate the contrast. And in the case of total colonic Hirschsprung's disease, a foreshortened or question mark colon can be seen on the contrast enema. The second part of a diagnostic workup for Hirschsprung's disease, and most important, is the rectal biopsy. It is the true definitive diagnosis. So what are the buzzwords on the pathology report that would make us think this is Hirschsprung disease? Typical features on the biopsy include absence of ganglion cells, presence of hypertrophic nerves, abnormal pattern of colon esterase staining, and an absence of calretinine staining. To be considered an adequate biopsy, it must be taken from the rectum at least 1 cm above the dentate line, and must include both mucosa and submucosal layers. What are the different ways to get a biopsy? A rectal biopsy can be obtained through suction technique or open full thickness technique. The suction technique is typically used for patients less than 6 months of age, and one should consider using a full thickness technique for patients older than 6 months or when a suction biopsy is inadequate. So Hirschsprung disease typically presents in a neonate, and as stated, the diagnostic tool of choice is a suction rectal biopsy. This is actually very common and done at the bedside. A small device is inserted into the rectum and deployed, which takes a partial thickness piece of rectum, and this is sent down to the lab. This is painless. Typically this will diagnose Hirschsprung disease, but if this test is non-diagnostic, the patient can go to the operating room for a full thickness rectal biopsy done transanally. Now in very rare cases, typically the older patients, there is an option for anal rectal manometry. When doing anal rectal manometry, there is a lack of the recto anal inhibitory reflex, or RAIR, R-A-I-R. This reflex may be absent in other conditions as well, and some children have a false positive test. Okay, so you do the anal rectal manometry, and then they don't have a RAIR, or you, I guess, have an absent RAIR. What do you do next? So any patient with an absent RAIR must undergo a rectal biopsy for confirmation of the diagnosis. Okay, so you got the contrast enema. It made you think we should move forward with either a suction rectal biopsy or a full thickness biopsy of the colon. And then the pathology report comes back and says, hey, this is aganglionosis. This is Hirschsprung disease. So we have the diagnosis. What do you do next? Well, the first thing I usually do is talk to the family and give them education about the disease, because most of them have never heard of it, and they're not sure what to expect. I usually tell them that their child will need this condition managed for life, but that our expectation is that he or she will also live a normal life with some close management and care by the doctors and nurses. So we set the expectations for the long term, but what are some short term things that we talk to the families about? The NPO babies who are diagnosed with Hirschsprung disease will typically manage with irrigations, antibiotics if they show evidence of enterocolitis, and NPO or NG tubes if they're distended. Many times though they're not distended and you can kind of keep them decompressed by doing irrigations, allowing them to have breast milk until you get to the point where they're ready for surgery. Okay, so let's forget about the neonate. What about a children who's a little bit older with Hirschsprung disease? Older children are a little bit more difficult in that they've had this problem since birth, and a lot of times the colon has become dilated. And so they're not amenable to just doing a primary pull through in many cases. So children like that will start on an enema program. Some may need diversion more proximally to give the colon time to decompress. Alright, before we move on to surgical technique, let's just take a step back. What are the goals of surgical management? There are three goals to the surgical management of Hirschsprung disease. First, identify the extent of the aganglionic segment. Second, resect that segment. And third, restore the bowel to its continuity. Alright, so we looked at our preoperative imaging. We're coming up with a plan for surgery. But keep in mind, we have some options for a surgical approach. The three procedures for Hirschsprung disease all involve a transanal approach of removing the aganglionic colon and pulling down healthy colon and sewing it to the anus. Where they differentiate from each other is how much rectal dissection is performed and how the anastomosis is performed. We have the Swensen technique, which is a full thickness dissection and anastomosis. There's the Suave procedure, which is a mucosectomy. You leave a cuff of aganglionic bowel and bring the ganglionated bowel through that cuff of rectum and perform your anastomosis. And then there's the Duamel procedure, which is performing a pouch with an anastomosis of aganglionic and ganglionated bowel. Alright, what are the postoperative complications to keep an eye out for? So, I like to divide these up into the early and the late complications. So, early on you can see really bad diaper rash and excoriation. It can often need to be treated like a burn. Obviously, anytime you're anastomosing bowel, you have to be worried about a leak, which fortunately is rare in these patients. But probably the main thing everyone needs to be aware of is Hirschsprung's associated enterocolitis. Okay, let's change gears. How about Hirschsprung's associated enterocolitis? Hirschsprung's associated enterocolitis is poorly understood and likely is an inflammatory condition secondary to bacterial overgrowth. A child who presents with enterocolitis shows up to an emergency room with abdominal distention, vomiting, fever, change in bowel habits. This must be recognized as potential enterocolitis and treated urgently. When we treat these patients with enterocolitis, it is important to provide fluid resuscitation, digital rectal exam, and colonic irrigations. Depending on the severity of the enterocolitis, we sometimes add broad-spectrum antibiotics and we usually start these patients on metronidazole. If you want to see our guidelines for Hirschsprung's associated enterocolitis, download the Stay Current Pediatric Surgery app. It's in the Apple App Store. It's in the Google Play Store. We got guidelines like this and many others for you. What's the long-term prognosis for these patients? I do mention that about 80% of kids with Hirschsprung's disease are constipated and will need some kind of management. So assuming that the operation's been done well and that there's not any transition zone or strictures, we expect that most of the patients are going to do very well and be in kindergarten socially confident. Well, there you have it. Our videocast on Hirschsprung's disease. If you like this one and you want more like it, subscribe to our YouTube page and download the Stay Current Pediatric Surgery app. But until next time, I'm Rod Girardo from Cincinnati Children's and remember, knowledge should be free.