Pyloric Stenosis with Dr. Alex Bondoc

Hi everyone, I'm Kim Pribbin and I'm Em. Goddy. We are research fellows at Cincinnati Children's Hospital. Today we will learn more about the diagnosis and management of pyloric stenosis with Doctor Alex Bondock, a pediatric surgeon from Cincinnati Children's. Pyloric stenosis is a condition in infants where the pyloric muscle becomes thickened or hypertrophied, thus creating a much narrower passage between the stomach and the small intestine. This muscle thickening can block food from passing from the stomach into the small intestine and prohibits digestion. The classic symptom is projectile vomiting after feeding, followed by signs of hunger, which can lead to severe dehydration and weight loss. In today's podcast, we're going to review in detail to understand better how to diagnose and manage these patients, both medically and surgically. Let's start with the case. Our patient is a 7 weeks old male with no past medical history, whose parents reported 5 weeks of vomiting. He was initially breastfed, but due to persistent vomiting, the parent tried 3 different formulas without any improvement in the patient's symptoms. His vomiting would only occur after feedings and was described as large volume, projectile and not bloody or bilious in nature. Initial lab work would show a chloride level of 88 millimoes per liter and a bicarbonate level of 35 millimoles per liter. So what are the potential medical and anatomical conditions we would want to consider in a child this age, what would be potentially the most common, most likely diagnosis of a baby that spits up? Reflux, G E R, reflux, right? Reflux is really common in the first year of life. A few other things you may consider initially is a cow milk allergy, gastroenteritis, or maybe even a viral infection. Those are by far the most common things that you would see in an infant this age. You would then want to investigate less common anatomical causes like pyloric stenosis, proximal obstructions, or gut duplication, pylorospasm, duodenal webs, or pyloric atresia. One of the most important Differential diagnosis assessments for this patient is to determine if the vomiting is bilious or non-bilious. In our patient, the vomiting was non-bilious. Don't forget the bilious vomiting should be considered as an emergency in an infant. So what would your initial diagnosis of this patient be? We'll say, let's focus on pyloric stenosis now. What are the risk factors for pyloric stenosis? There are several risk factors to consider when diagnosing an infant, for example, being a First born child or a male dramatically increases the infant's chances of developing pyloric stenosis. Other factors like family history, maternal diabetes, being bottle-fed, prematurity, and even birth via C-section or exposure to certain antibiotics such as erythromycin can also play a role. It is also important to remember that pyloric stenosis usually affects babies between 2 and 8 weeks of age, but can occur anytime from birth to 6 months. So it's a relatively rare diagnosis, about 4 to 5 in 1000 live births, and the preponderance is heavily male. And then there have been lots of papers about other risk factors or epidemiologic findings related to pyloric stenosis, one of which is socioeconomic status. The Journal of Pediatric Surgery published a study in 2017 that took a retrospective approach, examined the data from 2007. 2012, this study reviewed 584 patients with pyloric stenosis and found that the African American infants presented with higher bicarbonate levels and lower chloride levels. Yeah, that same study also suggested that babies that come from uninsured families also had lower chloride and higher bicarb levels upon presentation, and they often had longer times between the diagnosis and the operating room, though this delay may be due to the need to correct electrolytes. And is it a cause and effect relationship? Perhaps not, but we're talking adversity. This is a patient population you have to be aware of. Perhaps they're not seeking care as soon or they've been placed in the waiting room. They're not being seen as fast. Hard to say. When looking at other risk factors, a large scale study out of Denmark and Holland found that pyloric stenosis is 87% heritable. This makes knowing the family's history crucial for diagnosis. It is particularly interesting that researchers were able to identify a molecular diagnostic marker. They can now trace specific genetic changes that may indicate the risk for pyloric stenosis. After reviewing a patient's history, the next step is a physical exam and ordering labs and imaging. A key physical exam finding is what is often called a palpable olive in the upper right quadrant, which is actually the palpable stenosis muscle. And now, Doctor Bondo will tell us what are some tips on how to find the stenosed area. As you're rolling the hypertrophied muscle over the retroperitoneum or even over the spine, so they tell you to warm up your hands, have mom or dad holding them tight so that they're not upset, and then maybe sometimes you can elicit it, especially if it's particularly large. All right, so once you're done with the physical assessment, the next step is reviewing the lab results. You really want to pay close attention to those electrolyte panels because signs of dehydration in those panels are very common and are part of the diagnostic criteria. Typically. you'll see issues like hyperbilirubinemia, hypochloremia, and elevated bicarb levels. Addressing these levels as soon as possible is really important as it can become life-threatening very quickly. The cause of these abnormal labs are related to the chronic vomiting and poor nutritional intake. The loss of chloride and hydrogen ions can lead to hypochloremic metabolic alkalosis. Bicarbonate also becomes elevated and the excess is excreted. In the urine, which obligates sodium loss to maintain electron neutrality because water loss follows sodium excretion, the patient becomes even more hemodynamically unstable. There is an association with Gilbert's syndrome and pyloric stenosis as well. We've had some patients incidentally diagnosed with that disorder when they came in for pyloric stenosis, when they had their labs checked. Next, we would want to review the imaging on the patient. The common practice is to Order a standard non-invasive, non-ionizing ultrasound to help the diagnosis. When reviewing the ultrasound, the team would want to measure the pyloric channel and the muscle thickness. Any muscle thickness greater than 4 millimeters and a pyloric channel length greater than 15 millimeters would suggest the patient has pyloric stenosis. Once we have a diagnosis, the next big step is fluid and electrolyte resuscitation, especially since these patients can have severe metabolic alkalosis. In a 2008 and subsequent 2016 follow-up study published in the Journal of Pediatric Surgery, they were able to really identify the specific fluid resuscitation care pathways needed to stabilize these patients. The treatment plan also reduced the number of blood draws and did not delay the time to surgery, which is pretty impressive. In this study, the researchers suggest administering a bolus of isotonic saline followed by maintenance IV fluids. This can be a dexterous 5% and Half normal saline, but they wanted you to add 20 milliequivalents per liter of potassium chloride. It is also important to avoid nasogastric compression because you really want to avoid exacerbation of the metabolic alkalosis. So after fluid resuscitation, let's say that the baby isn't stable enough to go to the operating room. How can you medically manage pyloric stenosis? You could aggressively observe the patient. But atropin is a traditional medical management, and it's essentially fallen out of favor because how good pediatric anesthetists are and there isn't necessarily a high concordance rate between congenital anomalies that would make a patient, a baby, a high anesthetic risk. When considering all of this and the fact that it is a 45 minute curative operation that can be done safely and quickly, you are likely choosing that option. In this case, our patient was stabilized and was able to go to the OR. Now, let's talk a little bit about the surgical management of pyloric stenosis. First question would be, do you order pre-op antibiotics? According to a 2023 study from Journal of Pediatric Surgery, antibiotic prophylaxis may be unnecessary for a pyroyotomy and may carry unnecessary long-term side effects. Next, you'll want to decide if your pyloromyotomy will be done laparos. Escopically or as an open procedure. But before we review the surgical setup and technique, Dr. Boondo has an interesting piece of history about the pyloomyotomy procedure. The first pyloomyotomy was done actually the year before by someone else, but Ramstead was the one who popularized it and the spreader bears his name. He used a coffee spoon and he actually intended to do a pyloroplasty, but ended up doing. Myotomy only because the baby got unstable or, you know, they couldn't do it appropriately, so we only did the myotomy. So that's how we figured out the myotomy would be curative. That's a pretty interesting use of a coffee spoon. Now, let's talk more about the pre-op and the surgical procedure. Once we choose our approach and get the baby into the OR, the next step is to ensure that there is gastric suction in prior to induction. We didn't put an NG in, so we're paying the price for that. But what we typically will do, or what some of the old school anesthetists, and I would assume that they've taught the fellows and their junior partners is you will suction the baby while awake in 3 different positions, head down, turn to the right, turn to the left to make sure you've sucked out that big atonic bag. Why is this step so important? Because again, you relax the baby. You have no NG. The baby vomits and aspirates. So it's very specific to paroxysmosis because of what's happened metabolically, physiologically with the stomach. In this patient, Doctor Bondak chose to proceed with a laparoscopic procedure. Let's walk through some important surgical techniques and tips. Positioning wise, you would want to actually turn the baby perpendicular to the long axis of the bed and plan to operate from the baby's feet. The surgeon would start by making 3 incisions, one in the umbilicus, one in the right upper quadrant, and the other in the upper left quadrant. You have the scope at the belly at the umbilicus, and then 2 stab incisions, right? So what size instruments are we using? 3 millimeter instruments. So again, just think about all these things that if someone opens the 5 millimeter instruments, that means you've got to make a big incision. It is important that the full extent of the bovie tip is in the patient and the surgeon is able to turn the bovie while moving it. You will want to identify the theoretical anatomic demarcation of the pylorus and duodenum by identifying the pyloric sphincter and the duodono jujunal junction. You will also generally see one well-defined vein with the rest around it looking like regular gastroepifloic vessels. If you see where it goes, you can usually see the bulging of the muscle. So how do you know how long to make your myotomy? This is why you should know how long the channel is, because if it's 1518 millimeters. The 3 millimeter Maryland grass for when you open it completely is 13 millimeters. If you only make a 13 millimeter myotomy on a 15 or an 18 millimeter channel. You're going to have an incomplete myotomy. Now that the stenosis has been found intraoperatively, what techniques are used to address it? One of the most common, that's the way I was taught to do it, is you take both ends of the grasp or the of the slit, you score the pylorus, the serosal surface of the pylorus, find one way in with the bovie blade, twist it so you crack the muscle, and then you can get this spreader, and it's got that serrated, gentle jaw on both sides, because then it grips the muscle and spreads it. Part and then you grab both ends of the separated muscle and it's supposed to move independently of each other. One thing to note is if the myotomy is incomplete, you might feel resistance as you grip the muscle, or they may still move as if they're connected. It also might be a little bloody because it's all done bluntly, and oftentimes you'll actually see the mucosa bulging through the hole. The other thing sometimes we can do is when there's blood or serous fluid, I'll have the Anesthetist put air down a suction catheter and theoretically looking for bubbles of air if you've violated the mucosa. I also lay a piece of momentum on top of there. All right, what about an open polyomyotomy? What technique does Dr. Bonddo prefer? So the way I was taught was to do it through a perambilical incision and then you tunnel up, because remember, again, another nice thing about working on babies is you can make a small incision, but you can stretch their skin and move it around so that you Get all the way up to the right upper quadrant through a perambilical incision. It is also common practice to use a transverse incision. All right, so what complications and risks would you tell the family about when you get consent for either of these procedures? When talking with the families, it is important to share that while the outcomes are generally really good, some of the risks of the procedure would be an incomplete myotomy, mucosal perforation, aspiration, and maybe wound infection. Other weird things about this. Operation are incisional hernias actually because you've made a stab and typically they don't close the fascia on those stab incisions in the left and right upper quadrant. I've seen two omental hernias, so I always try to close it with at least one little micro stitch. And what about the complication rates? The rates of complication after pyeloromyotomy, they're either equivalent or better actually with open because I think to me lap pyloromyotomy is an experience and a feel operation. Because like we said, there's no magical way to know exactly how complete your myotomy is, because I definitely lose my nerve going towards the duodenum, and sometimes people will stop short. But overall, the risks are rare. So what are some post-op care instructions we can tell the families and the nurses after surgery? I tell them that it is very common for babies to vomit afterwards, and it doesn't necessarily mean that the operation didn't work. Why does this happen? My theory is that the stomach is still atonic, right? It's not going to remodel itself immediately. Sometimes if you're challenging the baby, they still will vomit, and that's OK. Now, once you get into days and complete intolerance of feeds, then you have to worry about something like an incomplete myotomy. Uh yes, that makes perfect sense because the stomach is getting back on track. We would want the patient to take nothing by mouth initially and then introduce feeds very slowly. And some researchers have demonstrated that following a more flexible protocol, such as reducing formula or volume if a baby vomits 6 times, but continuing to feed smaller amounts, and then increasing as tolerated, allows for greater flexibility and decreases the length of hospital stay. I think it's really important to educate not only the family, but also the pediatric care team on the hospital floors that some vomiting is expected and is actually acceptable. Just follow the protocol and keep trying smaller amounts of feeds and monitor closely. It is also important to monitor the patient for apnea and signs of pain. Overall, this procedure is a very well tolerated operation. Finally, looking at the studies on adults who had a pyloric myotomy as kids, it's pretty clear that they don't tend to have major issues like nausea, vomiting, reflux, or other gastrointestinal problems later in life. This suggests that long-term follow-ups are usually not necessary, which is really reassuring for both patients and the doctors. In this episode, we discussed how to diagnose and manage the care of children with pyloric stenosis. Here are a few things to consider. During the initial patient presentation, it is really important to get a good family history. Review of electrolyte panels and ultrasound results. When determining the next steps in the patient's care, try to get the patient's fluids and electrolytes balanced. It's really important for avoiding morbidity or mortality by stabilizing them for surgery. Surgery can be done either laparos. Escopically or as an open procedure with similar outcomes. And lastly, make sure that the care teams and families understand post-op care. Remember, the patients may vomit and it might be expected. Adjusting the amount and frequency of feedings will help speed up the recovery. Thank you for listening to this episode. Globalcast MD along with Cincinnati Children's Hospital, sharing knowledge to improve child health around the globe.