Pediatric Inguinal Hernia in Brief: Presentation, Workup, Diagnosis, Perioperative Considerations

Inguinal hernia repair is the second most common surgery performed by pediatric surgeons. So today, we're going to break down the basics of pediatric inguinal hernia. Hi, my name is Mira Kodagalli, and I'm a pediatric surgeon at Cincinnati Children's Hospital. Today, we're going to be reviewing inguinal hernias. Let's kick things off with some basic anatomy. Indirect hernias are above the inguinal ligament, but lateral to the epigastric vessels. Direct hernias are above the inguinal ligament and medial to the epigastric vessels. And then femoral hernias, those are below the inguinal ligament. So do we see all of these types of inguinal hernias in the pediatric patient? The incidence of inguinal hernias overall ranges from about 1% to 5% in full-term newborns, and this increases to about 13% in premature infants who are less than 32 weeks of gestational age. Most of these hernias are largely indirect, over 90% in children. Direct hernias are pretty rare in children and are much more commonly found in adolescence. And femoral hernias are also very rare in children, and as in adults, are more common in females. Where do indirect hernias come from? So indirect inguinal hernias in children are a congenital anomaly, meaning that they've occurred in development and are present at the time of birth. These inguinal hernias occur as a result of the failure of the processus vaginalis to fuse. In utero during gestation, the processus vaginalis should fuse to become the tunica vaginalis. The right processus vaginalis usually obliterates after the left, so that explains the higher prevalence of right-sided hernias. What if it just narrows, but it doesn't totally close or obliterate? You can get a communicating hydrocele, where fluid can move from the peritoneal cavity through the inguinal canal and into the scrotum. But then if the proximal part closes and the distal part doesn't obliterate, then you get a non-communicating hydrocele where some fluid is trapped. What are some risk factors for inguinal hernia in children? The number one risk factor for inguinal hernias in children is prematurity. As we mentioned before, premature infants have a much higher rate and risk of inguinal hernias than those who are full term. Some of the other factors associated with an increased risk of inguinal hernias in kids include male sex, family history of inguinal hernias, a history of an undescended testicle or hydrocele, and a connective tissue disorder. Now, for patients who present more symptomatically, those are going to be patients with increased intraabdominal pressure. So think about patients who are chronically ventilated, patients who are chronically constipated, patients with cystic fibrosis, uh VP shunts. The list goes on and on. Now, let's change gears a little bit. Let's do a case. The differential diagnosis for a growing mass in a child includes an inguinal hernia, most likely indirect, although there's a rare chance it could be direct, hydroceles or lymphadenopathy. If that growing mass is associated with significant pain, your differential diagnosis should also include testicular torsion, epididymitis or orchitis, or torsion of the appendix testis. And then one more diagnosis to keep on your differential. Think about an undescended testicle or a retractile testicle. Make sure to do a good physical exam on all of your patients, but in the male ones, double check to see that both testes are in the scrotum. All right, so now let's talk about timing for the surgery. So timing for decisions about repairs of inguinal hernias really has to balance the risks of anesthesia with the risks of incarceration associated with the hernia. It is, in general, considered an elective operation that does not need to be urgently performed, but we do know that younger children have a higher rate of incarceration. It's actually kind of alarming. I mean, more than half of the incarcerations that we see are in patients that are less than six months old. And then two-thirds of incarcerations are in those patients that are less than a year. Then think about the premature patients. If the corrected gestational age is less than 60 weeks, they're at a pretty increased risk of post-operative apnea. So you got to admit those patients after you do the repair. Okay, so let's now talk about the presentation. Children with an incarcerated hernia may present most commonly with pain, particularly growing pain. They may also have abdominal distension or emesis if obstruction is present due to bowel being in the incarcerated hernia. Prolonged incarceration can result in strangulation, particularly of bowel contents, and so those patients who have a strangulated hernia may present with fever, tachycardia, leukocytosis, severe pain, or overlying erythema in the skin. But before you take the patient to surgery, you're going to want to try to reduce this hernia at bedside. How do you do that? One of the most important things I think in being able to reduce an incarcerated hernia is helping to keep the patient calm. Sometimes that means pain control and sedation because if the kid's crying and you're trying to reduce the hernia, you're going to have a bad time. You can place the patient supine and in the Trendelenburg position with their head down, and then generally we use two hands to try to reduce the hernia. So one hand to guide the contents through the inguinal ring, and the other hand applies gentle, steady pressure. This last point is really important. You have to keep applying pressure in a slow, gentle fashion and not just kind of come and go with your hands, because that gentle, slow pressure is what allows you to release the hernia. But the most valuable piece of this technique, patience. Because sometimes if there's incarcerated bowel, it's going to take time for the edema to get squeezed out. It may take several minutes at bedside to just squeeze that out so that it can reduce at all. So, take your time, make sure you have adequate pain control. So with all these different variations in presentation, how do you decide when to operate? The timing on when you repair an incarcerated inguinal hernia depends on whether or not you're able to reduce it. So if you can reduce it, then you want to go to the OR within the first 24 to 72 hours after the reduction. Now, the classic teaching that you got to wait for the bowel edema to come down before you go to the OR, that might be changing. Here's Dr. Todd Ponkse, another pediatric surgeon at Cincinnati Children's Hospital Medical Center. Now that with laparoscopy, you don't necessarily need to wait because it's really not that much more difficult in a laparoscopic case if there's swelling. In fact, sometimes the edema can help lift the peritoneum off. So, I would challenge that we may be changing the paradigm that if it's in the middle of the day and you have time availability and a patient has an incarcerated hernia, you could not even try to reduce it in the emergency room and just go straight to the operating room under laparoscopy, watch it get reduced under visualization, and then go ahead and do the laparoscopic repair, which is not that difficult even after an incarceration. All right, now let's talk about the approach for this repair. You can approach the repair of a pediatric inguinal hernia either laparoscopically or in an open fashion. The most important point is that you need to have high ligation of the processus vaginalis, whether you do it laparoscopically or open. You should consider evaluation of the contralateral side depending on the age of the child. Unlike in adults, we don't generally use mesh in the repair of the pediatric inguinal hernia. The outcomes between pediatric laparoscopic repairs and open repairs are thought to be similar, although there is some controversy on this topic. Okay, we don't have to get into controversies here, but are there any factors that would push you more towards an open repair? Particularly if you're considering that the child needs an orchidopexy in addition to their hernia repair, then most would approach that hernia in an open fashion. But keep in mind that you could also approach those laparoscopically and do the orchidopexy and the hernia repair. All right, when would you do a floor repair in addition to the high ligation? A floor repair should be considered in children who have long-standing or very large hernias, where you note that the floor might be blown out or unsupported. In those instances, you should consider a floor repair in order to buttress the repair. So many different options for approach, open, laparoscopic, different variables to consider if you're going to do multiple things at the time of surgery. But let's say we get past the surgery. What are some post-operative complications that you worry about? Complications are fairly rare after an inguinal hernia repair in children. The most common are superficial site infection, which occur in less than 1% of kids, and some risk of recurrence. The rates of recurrence do vary from 1 to 5% depending on which studies you look at. And then there's the rare stuff, think testicular atrophy or damage to the vas deferens. You could see a seroma, that's also rare, or a hydrocele. And then what are the post-operative instructions you're giving to this patient or the family? In general, we don't try to limit activities in children after a hernia repair. In general for children, we don't do this. Most children can return to normal activities within one to two days. All right, let's try another case. Let's say you have an incarcerated inguinal hernia and you cannot reduce it at bedside. What are we going to do? So the thing that's most concerning when you have an incarcerated hernia and you're not able to reduce it, particularly if you start to see overlying skin changes or things that might suggest strangulation, is that you would worry about bowel ischemia and necrosis. In the event that you happen to identify bowel that is necrotic, you can approach resecting that either through a groin incision or through a small midline incision. If you had to, you could even resect non-viable bowel through that groin incision, but keep in mind this isn't our only option. Otherwise, you can approach laparoscopically and run the bowel in order to evaluate for ischemia at that point, and then turn to fix the hernia either laparoscopically or open. Now sometimes you might get surprised too. A lot of times once the patient is put under anesthesia, an incarcerated hernia that you noted and were unable to reduce in the emergency department may actually spontaneously reduce with the patient's relaxation. All right, let's try a more difficult case. Let's say you have the inguinal hernia, but this time you can palpate an undescended testicle in the inguinal canal. What do you do? This is an important point related to your pre-operative workup of patients with an inguinal hernia. It's really important to do a thorough exam and make sure you understand whether or not those patients have undescended testes at the time of your pre-op evaluation. If a patient does have an undescended testicle that's palpable in the inguinal canal, then you should plan to do an orchidopexy at the time of your inguinal hernia repair. Let's keep throwing these scenarios out. How about you're in the middle of a repair and you notice that this kid doesn't have a vas deference? What do you got to work up that patient for? Um, children with an absent vas deference noted on hernia repair should be worked up for cystic fibrosis or for unilateral renal agenesis in the post-op period. All right, now let's say you have a male patient with ipsilateral testicular pain and tenderness after a hernia repair. What are you worried about? The thing that concerns you most if if patients are having significant testicular pain after a hernia repair is testicular ischemia. The best way to evaluate that is to get an ultrasound looking for Doppler flow. In general, these patients are monitored and observed with pain control and we only frankly remove a necrotic testicle and not necessarily one that is partially ischemic. All right, so let's summarize. Inguinal hernias are incredibly common. More so in that premature population. If you're worried about incarceration, that's going to be in those patients that are less than a year old. Once you decide to operate, you have a lot of options. You can go open, you can go laparoscopic, and a lot of variables in the patient and their presentation will push you one way or the other. And if you are going laparoscopic, just take a second and check out the contralateral side, especially in those premature patients. And that's all for pediatric inguinal hernias. If you like this content, go ahead and like and subscribe to our YouTube channel. Follow us in all of our social media channels, and make sure to download our stay current pediatric surgery app. It's in the Apple App Store, it's in the Google Play Store. But until next time, I'm Rod from Cincinnati Children's and remember, knowledge should be free.