Hirschsprung’s Disease

Hi, I'm Jason Frischer. And I'm Aaron Garrison. We're both pediatric surgeons at Cincinnati Children's. Today we're going to review Hirschsprung's disease. Hirschsprung's disease is a congenital developmental anomaly of intestinal ganglion cell migration that results in a functional bowel obstruction. I'm here today with Dr. Jason Frischer and Dr. Aaron Garrison, both pediatric colorectal surgeons at Cincinnati Children's to discuss Hirschsprung's disease. How does Hirschsprung's 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. However, some infants with Hirschsprung's disease do pass meconium. 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 this condition? Are there any predisposing conditions or familial associations? So Hirschsprung's disease is actually relatively common in a busy children's hospital. It's got an incidence of about 1 in 5,000 children. So it is something that does come up quite frequently. 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. So typically if we have patients with strong family history, we will have them referred to genetics for evaluation and screening for other potential malignancies. 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 disease. There are a few other syndromes that are associated with Hirschsprung disease including Wardenburg syndrome, congenital central hypoventilation, which is known as Ondine's curse and some others. What diagnostic workup should be performed? The three studies that should be considered for evaluating for Hirschsprung's disease include contrast enema, rectal biopsy and possibly anorectalmetry. Let's talk about those individually. A contrast enema can be performed in a child with suspected Hirschsprung's disease. We typically use a water soluble contrast enema and that help us, helps us differentiate between other causes of neonatal intestinal obstruction such as meconium ileus or intestinal atresia. The classic finding is a transition zone in the rectosigmoid, but that transition zone really can be located anywhere within the bowel. Other findings suggestive of Hirschsprung's disease include a rectosigmoid ratio of less than 1.0. That what that really means is that the Hirschsprung's disease, the aganglionic bowel is contracted and is narrow lumen compared to the dilated ganglionic bowel more proximal. 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. Approximately 10% of newborns with Hirschsprung's disease may lack the typical findings on a contrast enema. So if there is a clinical suspicion of the disease, a rectal biopsy must be considered. The second part of a diagnostic workup for Hirschsprung's disease and most important is the rectal biopsy. It is the true definitive diagnosis. In a child with suspected Hirschsprung's disease, one can perform a rectal biopsy to confirm the diagnosis. Typical features on the biopsy include absence of ganglion cells, presence of hypertrophic nerves, abnormal pattern of cholinesterase staining and an absence of calretinin 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. A rectal biopsy can be obtained through suction technique or open full thickness technique. The suction technique is typically used for patients less than six months of age and one should consider using a full thickness technique for patients older than six months or when a suction biopsy is inadequate. And would we get an anorectalmetry on all of these patients? Anorectalmetry is a newer modality that is sometimes used. One must understand the findings for a patient in Hirschsprung's disease that when doing anorectalmetry, there is a lack of the rectal anal inhibitory reflex or rare, R A I R. This reflex may be absent in other conditions as well and some children have a false positive test. So any patient with an absent rare must undergo a rectal biopsy for confirmation of the diagnosis. I like to think and use anorectalmetry to rule out Hirschsprung's disease in some patients. But when it's undiagnostic or even positive, I still perform a biopsy to provide a definitive diagnosis. What should we do once a diagnosis is made? So 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 um and care by the doctors and nurses. The other short-term thing that we teach families to do is rectal irrigations and this is best taught before you actually do the operation. So getting the family familiar with them because as we'll talk about latertis is the the biggest thing that we get concerned about is it's it's the life-threatening part of Hirschsprung's disease. Nicu babies who are diagnosed with Hirschsprung's disease will typically manage with irrigations, antibiotics if they show evidence oftis and PO or NG tubes if they're distended. many times though they 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. 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 proximately to give the colon time to decompress. Everyone we managed a little bit differently, but those are a little bit more challenging group to kind of decide which operation you're going to do and when. What are the goals of surgical management? There are three goals to the surgical management of Hirschsprung's disease. First, identify the extent of the aganglionic segment. Second, resect that segment, and third, restore the bowel to its continuity. What are the principles of surgical management of Hirschsprung's disease? So there are a couple things to keep in mind before you do one of these operations and that's you can use the contrast enema as a roadmap and most times they are accurate to where the the level is, but not always. So there are a few different techniques to obtain your biopsies. We usually do them laparoscopically or we'll pull the colon out through the umbilicus to take a full thickness biopsy. The goal is to get past the aganglionic segment into the normally innervated bowel that does not have hypertrophic nerves and ultimately to pull that segment of bowel down through and perform your anastomosis above the dentate line. What are the common surgical options for Hirschsprung's disease? There are three main surgical options that one would consider when performing surgery for Hirschsprung's disease. There's the Swenson, the Suave and the Duhamel. It's important to understand what each procedure entails as well as the pros and cons of each. Our preferred technique is the Swenson procedure. Essentially that's where you pull down the aganglionic bowel, you perform your full thickness anastomosis about 1 to 2 centimeters above the dentate line. We like that because it leaves really the most minimal amount of aganglionic bowel that you can. Uh and I think it's possible to do the operation without a lot of stretch or injury to pelvic nerves and blood vessels. Some of the time you can do this completely transanally. I prefer doing a combination of laparoscopic and transanal to really minimize the amount of stretch and transanal dissection that that you're doing. But it is very important to be cautious about injuring the urethra as it's quite close especially in boys. The Suave procedure is another technique very popular and is actually the performing of a mucosectomy from a transanal approach slightly above the dentate line and pulling through the normal bowel. Again, this can be performed in combination with a abdominal approach either open or laparoscopic to do a majority of the dissection, but the actual anastomosis and very distal dissection is a mucosectomy for a determined length which can be anywhere from one to many centimeters long. I think over the course of time, the length of that mucosectomy has gotten shorter and shorter. The actual anastomosis is performed within a cuff of aganglionic rectum. And so in essence, the Suave procedure is performing a mucosectomy leaving a cuff of aganglionic bowel and you're pulling through ganglionic bowel through that aganglionated cuff down to perform your anastomosis slightly above the dentate line. The pros of this approach is theoretically less injury to pelvic structures, the nerves in that region and other structures such as the urethra and vagina which are in close proximity. The cons of this procedure is that there are times when that aganglionic cuff becomes stiff enough to cause an obstruction or an outlet obstruction of your pulled through ganglionic colon. And what about the Duhamel procedure? So the Duhamel procedure is where you would intentionally leave a portion of the aganglionic rectum behind and bring the normally ganglionic bowel posterior to that rectum. You then make an anastomosis by using a stapler and that makes a common channel between the two structures. The pro side of this is that you're not dissecting as much in the pelvis, so there may be less injury to pelvic structures. However, the downside that we see is that some of the children can have trouble evacuating that pouch. So there may be higher risks of having constipation and um stool withholding with a Duhamel. Furthermore, where you do your anastomosis, it can often leave a spur if the anastomosis is not large enough. So sometimes we have to go in and uh revise that spur or make the anastomosis larger. There are three different surgical techniques that we just reviewed. All of them are equally effective and one should perform the technique they're most comfortable with. To review, we have the Swenson 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 ganglionic bowel through that cuff of rectum and perform your anastomosis. And then there's the Duhamel procedure, which is performing a pouch with an anastomosis of aganglionic and ganglionic bowel. What are some common complications for these operations? 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 that 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. So anastomotic leaks obviously are usually going to show up in the first week after surgery, fever, abdominal distension, uh maybe free air and that often requires another operation or a more proximal diversion depending on the extent of the leak. But probably the the main thing everyone needs to be aware of is Hirschsprung's associatedtis and this is truly a life-threatening problem that everybody needs to be educated on. How do you diagnose and treat Hirschsprung's associatedtis? Hirschsprung's associatedtis is poorly understood and likely is an inflammatory condition secondary to bacterial overgrowth. A child who presents withtis shows up to an emergency room with abdominal distension, vomiting, fever, change in bowel habits that could be either diarrhea or not passing stool at all and this must be recognized as potentialtis and treated urgently. When we treat these patients withtis, it is important to provide fluid resuscitation, digital rectal exam and colonic irrigations. Depending on the severity of thetis, we sometimes add broad spectrum antibiotics and we usually start these patients on metronidazol. Atis can present similarly as gastroenteritis, but because of the severity that is potential in a patient withtis, we treat them as if they havetis and again, the key tenants to treatingtis are fluid resuscitation, digital rectal exam and colonic irrigations. Adding antibiotic coverage whether it be through metronidazol or broad spectrum antibiotics is dependent on the severity of the presentation. What is the long-term prognosis for these patients? When families ask me what is their prognosis? I think it's hard to tell from the beginning because Hirschsprung's disease is such a spectrum of disease and presentations and kids who have more syndromic types really are a different category. I would say the most common rectosigmoid type patients though, really should do well and and should be continent by the time they enter kindergarten. I do mention that about 80% of kids with Hirschsprung's disease are constipated and will need some kind of management. I think we do manage their constipation pretty aggressively here. Managing that early and aggressively, I think we prevent some of the complications and things that can show up later such as when the bowel gets distended and defunctionalized. 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 uh socially continent. For a patient who isn't doing well after a pull through, what are your management options? Great question. I think you have to have a systematic and organized plan when taking care of patients who aren't doing well after surgery for Hirschsprung's disease. And the first and foremost is to take obviously a good history and a good physical exam. If you find that there's a stricture at your anastomosis from a prior pull through for Hirschsprung's disease, then that needs to be addressed either through dilations or revising the pull through procedure. If you don't see a stricture on your physical exam, then typically I get a contrast enema and perform a rectal exam under anesthesia and repeat biopsy to further investigate these patients. Then you have to define whether it's anatomic problem or a functional problem. So anatomic problems can be a twist in your pull through, an obstructing cuff, a non-functioning Duhamel pouch or you could see from your biopsy, you have a transition zone or continued aganglionic segment causing a functional obstruction and therefore causing problems in the patient who already had a pull through. For patients with an anatomic problem, you have to revise the pull through typically. For patients who do not have an anatomic problem, a patient can undergo bowel management if necessary or botox injection to relieve sphincter tone if necessary, and sometimes even further management or work up including motility studies may be required to further delineate if there's a segment of colon that's just not functioning properly. These are very complicated patients and a systematic approach with a physical exam and then a contrast study and an exam under anesthesia helps you start to delineate these patients and then further treatment either with bowel management or motility studies may be required to really work up these few patients that really struggle after pull through for Hirschsprung's disease. To see our guideline on Hirschsprung's associatedtis, either see the link in our outline or in the State current app, see the suspected Hirschsprung's associatedtis guidelines. Garrison, what are your clinical pearls for trainees out there? Things that they should know right off the top of their head when it comes to Hirschsprung's disease. I think there's a couple things or potential traps that you can fall into. So if you're in surgery doing an operation for Hirschsprung's disease and you keep leveling and you're getting past the splenic flexure, I think that's a point that I've been taught to stop and await your permanent sections and then do a diversion with an ileostomy. The reason being you don't want to start pulling through bowel that you don't need to remove and you also don't want to start doing pelvic dissections when uh you're potentially dealing with a total colonic Hirschsprung situation. I think uh one of the other ones is just, you know, continuing to be aware that you could have a patient with total colonic Hirschsprung even if uh the contrast enema doesn't quite reflect that and being prepared to doing ileostomy and not rushing to do something in the in the neonatal period kind of take a more long-term approach to it. I think we've all seen patients who kind of struggle with episodes oftis early in life and they ultimately just do tend to kind of outgrow it. So don't necessarily feel like there's something wrong that you did something wrong as long as you've kind of taken the steps that Dr. Frischer outlined above and made sure that there's nothing anatomically causing these episodes, then making sure the family knows how to treattis, uh making sure there's no stricture and being aggressive about medications, sometimes starting laxatives um pretty early on can help quite a bit. Um I didn't know Frischer, what pearls would you would you give? There are so many pearls, but a few that I think of are exposure. I think when doing this the transanal dissection, having good exposure, we like to use the loan star retractors. Some people use just sutures to expose the anal canal, but I think good visualization of the anal canal is important, which brings me to my next point, which is understanding the anatomy of the anal canal and really being able to identify the dentate line. So I think it is imperative that you identify the dentate line because your dissection transanally, whether that be through a Swenson, Suave or Duhamel technique, you need to make sure that you're starting your dissection above or proximal to the dentate line in order to get a good result. When we perform our pull throughs, we usually like to straighten out the colon and sort of remove that sigmoid or S curve in the sigmoid to allow for sort of a straight line evacuation path for the stool and also allows for easier irrigations when needed uh for patients with potentialtis. Which leads me to the last point, which I think is one of the most important points, which is prior to performing a pull through procedure, I ensure that our families are instructed and can perform irrigations so that if their child happens to havetis or develop signs and symptoms oftis, the number one treatment is irrigations and I would have my families perform irrigations before they even bring the patient to the emergency room. And so all patients before they get their pull through and when they're ready to go home are able to perform irrigations before the pull through and it go home with the proper equipment and supplies to do the irrigations. This is Roger Ardo from Cincinnati Children's Hospital, the contributing editor for this audio chapter. What else do you want to hear? Let us know in the State current app, Twitter, Facebook or Instagram pages. And remember, knowledge should be free.