BOB in Ped Surg 2023 - CAPS Winner - Christina Theodorou, MD

All right, we're going to go on now to what's next? Is my turn now? Yeah, it's. Okay. All right. So we are doing the next society, um, is now did you want to show that, you show that slide later, right? Um, so we have the the next society is the caps meeting. Um, and caps actually, uh, won last year, so they're they're the the the uh, what do you call it? They're the the reigning champions, so they have to we have to see if they can be dethroned. Um, and by the way, they had their annual caps meeting in Ontario, September 28th to the 30th and you can scan the QR code there to learn more about it. So these are the three participants of the finalists of the best papers from last year's Canadian Association of pediatric surgery meeting. First, we have Dr. uh Joshua Ramgist, who is a fellow of general surgery at uh a hospital for sick children in Toronto. Um, he is uh developed a five point and cancer recovery protocol for pectus excavatum. It's a retrospective study that aimed to compare the outcomes in patients that underwent a minimally invasive uh pectus excavatum repair uh before and after implementation of ERAS. Uh, the next one is uh Dr. Christina Theodoro, uh who is a resident at UC Davis Medical Center, and hers is evaluation of a novel biodegradable polyurethane patch for repair of diaphragmatic hernia in a rat model. Uh, and this was a pilot study, a pre-clinical study that evaluates the novel polyurethane patch for repair of CDH in comparison with other known patches. And finally Wendy Song, who is a medical student at University of British Columbia presenting a comparison of operative and anesthetic techniques for her repair in infants. This is a retrospective cohort study between 2016 and 2020 where surgeons did open or laparoscopic procedures and general or caudal anesthesia for inguinal hernia repair and evaluated the surgical outcomes and resource utilizations of all those different combinations. So again, we have the um Eras, we study for pectus, we have the biodegradable polyurethane patch and we have the different anesthetic options and the outcomes for uh her repair. So let's go to the polls. Spend a medical minute with Calida Health. Childhood obesity is very prevalent in the United States, unfortunately, about 18% of the childhood uh population struggle with obesity. One of the most important aspects of our program is that it's multi-disciplinary. So in addition to having medical docs see you, you're seen by registered dietitians, we have several psychologists. So each patient when they come in as a new appointment, can be seen by the whole team. They go to a room and then one after another the team members go in and see the patient. At Children's Healthy Way of Buffalo, we give an individualized treatment plan for the family. It's not just meant for the child, but the family as a whole. Our psychologists are very important to help us with the family piece of this and it's a family problem, a family issue. Most parents are desperate. They're frightened to death. This medical minute was brought to you by Calida Health. We see more than patients. All right, we're going to call it. We think we have the poll results here is uh evaluation of a novel biodegradable polyurethane patch for repair of diaphragmatic hernia in a rat model, a pilot study by Dr. Christina Theodoro from UC Davis. So, um, let's go ahead and roll that video. Thank you for the opportunity to present our pilot study on the repair of diaphragmatic hernia in a rat model, using a novel biodegradable polyurethane patch. We have no conflicts of interest to declare. The optimal management of congenital diaphragmatic hernia is an area of active research. In cases of large defects, diaphragmatic replacements are used, most commonly synthetic patches such as PTFE or gortex. However, these replacements are associated with significant morbidity, including hernia recurrence, bowel obstructions, and chest wall deformities as the child grows. The ideal diaphragm replacement would integrate with native tissue, mechanically match the function of the diaphragm, and allow for growth with the child. Our lab has collaborated with a bioengineering team in Texas who are actively investigating the use of polyurethanes or PU, which are elastomeric polymers. In particular, biodegradable forms of PU have been used in tissue repair recently, such as vascular and muscular tissue replacement and have high mechanical strength. We tested the PU patch in a rat model, comparing it to diaphragm repair with gortex. We hypothesized that this novel PU based patch would be durable and would not result in recurrent herniation. Additionally, the elastic nature of the patch would allow for more diaphragmatic excursion than gortex. We created a surgical model of diaphragmatic defects in rats, creating 4 mm defects followed by immediate patch repair. Each cohort had six animals, as well as a sham cohort of six rats who underwent laparatomy without diaphragm defect creation or repair. After repair, animals were survived for four weeks with fluoroscopic evaluation of diaphragmatic excursion with respiration at one and four weeks post stop. At four weeks they were euthanized and dissected to evaluate for hernia recurrence and adhesions to the patch. H&E staining was also performed. No recurrences were seen in either cohort. At one week, there was no difference in diaphragmatic excursion between sham, gortex and PU animals. At four weeks, gortex had limited diaphragm rise compared to sham, but no difference was found between PU and sham. There were no differences between PU and gortex at any time point. Moving on to the histology, an inflammatory capsule was formed surrounding both patches, and there was no significant difference in the size of that inflammatory capsule between the cohorts. In conclusion, the novel PU patch was similar to gortex in its short-term durability with no recurrences at four weeks. The PU patch allowed for diaphragmatic excursion that better matched the sham cohort. Both patches formed surrounding inflammatory capsules. However, further work is needed to evaluate long-term functional outcomes and to further optimize the properties of the PU patch. There are several limitations to this small pilot study. We had small numbers of animals in each cohort, thus likely underpowering us to detect significant differences. Additionally, the 4 mm defect size is small and we are performing additional studies using larger defects. Longer term follow-up will be important as most recurrences occur at least a few months out from surgery, most commonly within the first two years. As the biodegradation rate of the PU patch can be altered, by performing serial studies over a variety of time points, we hope to match the degradation rate to the rate of tissue and growth with the goal of complete replacement over time with native diaphragm tissue. Thank you. Great study and I don't know, um, if we are able to get the author in or not, but um, uh Tony, Alan, Cecily, any comments? Well, I would have loved to have asked the author what the uh rate of biodegradation is. It cannot be too fast of course, because then you'll have another hernia. So and I think what is the intrinsic strength at different time periods will be really important to understanding its use for a for a patch of the diaphragm. Right. Do you think, do you think um, what is your thought on absorbable versus non-absorbable patches in general? I think there's some evidence that the non that the absorbable patches are not as good and the recurrence rate is higher for uh diaphragmatic hernias. I personally use uh a gortex patch and that stays there forever and gets embedded into the tissues because of the high incidence of biodegradable patches and the high incidence of uh recurrent hernias. So I'm it's an interesting concept. There are other biodegradable uh resources that you can use, but I I'm a little concerned about the recurrence rate. Yeah. I I agree and I think this is true in a lot of things as we used to think that everything we were keep swinging back and forth. We used to think everything had to be uh non-absorbable, then we say, oh, we like absorbable, you may not need non-absorbable and now we're starting to find we may use it too much in different situations. Um, so I I think it's it's encouraging to see the uh, the better excursion, uh, that it may be less restrictive, uh, but you're right, it has to at least last durable amount of time and unfortunately we won't know, uh, how long it last, to be honest. And another question Todd I would have asked is, uh, you know, this is a short study. Perhaps it'd been better longer to see what actually the ingrowth is and what the actual diaphragm looks like once the uh the polyurethane has reabsorbed. Would that satisfy you, Tony? That if you could see, let's say you can't follow them for 10 years, but you could see the ingrowth was substantial. Would that satisfy you as data to or do you need to see the actual clinical recurrence? I think you could you could probably do some testing, maybe at six months a year and sort of see what the tensile strength, the breaking strength of the diaphragmatic tissue, whatever it is, that left behind. I think that's very important. Yeah. Just a short-term study showing that it works is I don't think uh adequate evidence to translate it to patient care. Great point. Yeah, like she says like in the presentation that she's now trying like larger defects, maybe she's also trying like amount like longer follow ups and things. To see if this work because it up to now it seems like it's pretty much as um useful as gortex, but yeah, we have to see.