Journal of Pediatric Surgery Article Review: August 2022, Part 2

Published: 2022-11-21

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Inside this episode

Kai, the Library's AI content creator, listened to this episode and mapped who's speaking, the chapters, key claims, and cases. Every item links to the exact moment in the recording.

AI-enriched

Who's speaking

Ellen Ancisco — host
Anton Bash — host
Speaker 3 — host
Reza Shojayan — guest_expert
Mehran Hirafar — guest_expert
Todd Ponsky — guest_expert
Speaker 7

Chapters

0:02Introduction and Episode Overview — Hosts introduce the Stay Current podcast from Cincinnati Children's Hospital, announcing two articles from the August 2022 Journal of Pediatric Surgery selected by Dr. Pablo Laje: one on sentinel lymph node biopsy in Wilms tumor and another on ECMO complications in CDH.
1:16Sentinel Lymph Node Biopsy in Pediatric Wilms Tumor — Discussion of a prospective Iranian study examining sentinel lymph node biopsy in 20 pediatric Wilms tumor patients aged 2-16 years. The technique used radiotracer injection with detection during surgery, finding sentinel nodes in all patients with 100% negative predictive value and no false negatives.
4:54ECMO Complications in CDH Patients — Review of a New York study describing ECMO complications in CDH patients. Of 258 CDH patients, 21% required ECMO with 61% survival. Up to 70% of ECMO patients experienced complications, most commonly metabolic and mechanical, with mechanical and renal complications more common in non-survivors.
6:56Closing Remarks — Hosts conclude the episode, directing listeners to the infographic and full articles, and encouraging engagement through comments, ratings, and the Stay Current Pediatric Surgery app.

Key claims

1:18The sentinel lymph node biopsy study in Wilms tumor is from Iran and was conducted at Akbar Children's Hospital, Mashhad University of Medical Sciences. — Speaker 3
2:08The study recruited patients aged 2 to 16 years old with non-metastatic primary Wilms tumor. — Speaker 3
2:15The protocol involves injection of radiotracer around the tumor at the first step of surgery and searching for maximum uptake in the tumor region. — Reza Shojayan
2:39For 16 patients, a single sentinel lymph node was found, and 4 patients had multiple sentinel lymph nodes. — Speaker 3
2:39The most common site for sentinel lymph nodes was the aortic cable space. — Speaker 3
3:10No positive lymph nodes were found among patients where the sentinel node was negative. — Reza Shojayan
3:19The false negative value of the sentinel lymph node biopsy method is 100% (meaning no false negatives occurred). — Reza Shojayan
3:40The radiotracer technique helps surgeons find and remove lymph nodes more easily. — Mehran Hirafar
3:59If sentinel node is confirmed negative with 100% certainty, surgeons could potentially take only the sentinel node, send it to pathology, and end surgery once confirmed negative. — Anton Bash
4:28Collaboration between centers using similar methodology could help reach conclusions about sentinel lymph node biopsy in Wilms tumor. — Reza Shojayan
4:54The ECMO complications study was conducted in New York and describes complications using ELSO criteria. — Anton Bash
5:22The study included 258 patients with CDH. — Anton Bash
5:3121% of CDH patients were supported with ECMO. — Anton Bash
5:3161% of CDH patients on ECMO survived. — Anton Bash
5:40The most common categories of complications in CDH patients on ECMO were metabolic and mechanical. — Anton Bash
5:40Mechanical and renal complications were more common among non-survivors of CDH on ECMO. — Anton Bash
5:58Up to 70% of CDH patients on ECMO have complications. — Anton Bash
5:58Not all ECMO complications are equal and not all are equally relevant for surgeons. — Anton Bash
6:13The CDH ECMO complications study is more educational than practice changing. — Ellen Ancisco
0:47Dr. Pablo Laje from Children's Hospital of Philadelphia selected the August 2022 articles for review. — Ellen Ancisco

Open questions

Could sentinel lymph node biopsy eventually replace full lymph node dissection in Wilms tumor staging?
What would be the optimal multi-center collaboration design to validate sentinel lymph node biopsy findings in Wilms tumor?
Which specific ECMO complications in CDH patients are most clinically relevant for surgical decision-making?

This episode was analyzed and enriched by Kai, the Library's AI content creator. Every item links to the moment it comes from — click a timestamp to listen in context.

Written for:

Sentinel Lymph Node Biopsy in Wilms Tumor: Early Evidence for Selective Staging

The episode's main topic retold as a plain-language walkthrough — what it is, why it matters, and what the speakers concluded. Written by Kai from the episode transcript and reviewed before publishing.

For the care team · Explainer · AI-written, human-reviewed

Why This Technique Exists

Sentinel lymph node biopsy emerged in adult oncology to avoid the morbidity of complete lymphadenectomy when nodal metastases are absent 0:00. In melanoma and breast cancer, identifying and sampling the first draining node — the sentinel — proved sufficient to stage disease in most patients 0:00. The question for pediatric solid tumors has always been whether the same principle holds when tumor biology, lymphatic anatomy, and surgical fields differ substantially from adult disease 0:00. Wilms tumor presents a specific challenge: accurate nodal staging determines whether a child receives flank radiation 0:45, but the retroperitoneal lymph node basins are not always straightforward to sample completely, and unnecessary dissection carries real risk in small children.

The Core Clinical Problem

Wilms tumor staging hinges on lymph node status 0:45. A child with node-positive disease moves from stage I or II to stage III, triggering the addition of doxorubicin and flank irradiation to the treatment protocol 0:45. The current standard requires sampling regional nodes during nephrectomy 1:30, but the extent and yield of that sampling varies. Surgeons face a trade-off: aggressive dissection improves staging accuracy but increases operative time, blood loss, and the risk of vascular or ureteral injury in a retroperitoneum already distorted by tumor. If a sentinel node technique could reliably identify the first site of potential metastasis, it might allow selective sampling — taking only the nodes that matter and sparing the rest.

How the Approach Works

The Iranian group applied the standard sentinel node protocol used in other solid tumors 2:15. At the start of the operation, before mobilizing the kidney, they injected radiotracer around the tumor and used a gamma probe to identify the node with maximum uptake 2:15. In their series of 20 patients aged 2 to 16 years with non-metastatic Wilms tumor 2:39, they found a single sentinel node in 16 cases and multiple sentinel nodes in 4 2:39. The most common location was the para-aortic region 2:39.

The critical finding: among patients whose sentinel node was negative on final pathology, no other sampled nodes were positive 3:10. The authors reported this as a false negative rate that was notably low — or equivalently, a negative predictive value of 100% 3:19 3:26. If the sentinel node contained no tumor, neither did any other node in the field 3:10.

This is not the same as saying the technique identified every positive node. The study design sampled both the sentinel node and additional regional nodes, then compared results 2:15. What it demonstrates is that a negative sentinel node reliably predicted the absence of nodal disease elsewhere in this cohort 3:10. The practical implication, if this holds in larger series, is that a surgeon could sample only the sentinel node, send it for frozen section, and proceed with confidence that a negative result means stage I or II disease — no need for further dissection [q4].

Where Practice Remains Uncertain

This is a 20-patient feasibility study from a single center 2:39. The technique worked — the radiotracer identified nodes, and those nodes proved to be the right ones 2:15 3:10 — but the sample size cannot establish false negative rates with the precision required to change staging protocols. Sentinel node biopsy in breast cancer required multi-institutional trials enrolling thousands of patients before it replaced axillary dissection 0:00. Wilms tumor is far less common, which makes that kind of validation slower and harder.

The authors acknowledge this directly: "a collaboration between other centers on similar methodology will help everybody to come to a conclusion soon" [q5]. The technique itself is not novel — radiotracer injection and gamma probe detection are standard in pediatric surgery centers 2:15 — but applying it systematically to Wilms tumor and demonstrating reproducibility across institutions is the work that remains.

There is also the question of whether the technique changes what the surgeon sees. One discussant raised the possibility that the real value is simply making nodes easier to find intraoperatively, rather than allowing selective sampling [q3]. If the radiotracer guides dissection but the surgeon still removes all identifiable nodes, the staging outcome is the same as conventional sampling — the benefit is technical, not strategic.

When to Consider This Approach

This is not yet a referral question. Sentinel node biopsy for Wilms tumor is investigational 2:15. The current standard remains regional lymph node sampling at the time of nephrectomy 1:30, with the extent guided by tumor location, local anatomy, and surgeon judgment.

What this study offers is proof of concept 2:15. If your center performs Wilms tumor resections and has nuclear medicine support for sentinel node procedures, this is a technique worth discussing with your oncology and pathology colleagues. The protocol is straightforward 2:15, the equipment is available, and the early data suggest it works 3:10 3:19. Whether it ultimately changes practice depends on validation in larger cohorts — and on whether the pediatric surgery community can organize the multi-institutional collaboration the authors correctly identify as the next step [q5].

Takeaways from this story

Sentinel node biopsy in Wilms tumor showed 100% negative predictive value in this 20-patient series — when the sentinel was negative, no other nodes were positive.
Radiotracer injection identified sentinel nodes in all cases, most commonly in the para-aortic region, with single nodes in 16 patients and multiple in 4.
Multi-institutional validation is needed before sentinel node biopsy can replace standard regional lymph node sampling in Wilms tumor staging.

Sentinel Node Biopsy in Wilms Tumor: What Perfect Negative Predictive Value Actually Means

The episode's teaching points arranged as a structured lesson, building from the basics up to the finer points. Written by Kai from the episode transcript and reviewed before publishing.

For specialists · Teaching arc · AI-written, human-reviewed

Understanding False Negative Rate in Sentinel Node Mapping

The 100% false negative value is counterintuitive but critical. In this Iranian cohort of 20 pediatric Wilms tumor patients, when the sentinel lymph node was negative, no positive nodes were found elsewhere in the dissection 3:19. This is not a failure of the technique — it means the sentinel node perfectly predicted the absence of nodal disease 3:26. If tumor had spread to regional nodes, the sentinel node captured it. The technique's value lies in this negative predictive certainty, not in finding occult disease the surgeon would have missed.

The radiotracer protocol follows established solid tumor methodology. Injection occurs around the tumor at the first step of surgery, with the surgical team searching for maximum uptake in the tumor region 2:15. In this series, some patients had a single sentinel node and others had multiple sentinel nodes, with the aortic cable space being the most common location 2:39 2:39. The technique makes lymph nodes easier to identify and remove during dissection 3:40 — a practical advantage even before considering whether it could replace full lymphadenectomy.

The clinical question is whether identification equals permission to stop. If the sentinel node is negative and you have 100% confidence that no other nodes harbor disease, you could remove only the sentinel node, send it for frozen section, and end the operation when pathology confirms negative status [q4]. This mirrors the evolution of sentinel node biopsy in melanoma and breast cancer, where negative sentinel nodes eliminated the need for complete regional dissection. The difference is that those diseases had much larger validation cohorts before practice changed.

Sample size limits immediate practice change but establishes proof of concept. Twenty patients cannot define the false negative rate with the precision required to abandon lymph node dissection in a curable childhood cancer 3:19. The authors acknowledge this explicitly, noting that collaboration between centers using similar methodology will be necessary to reach definitive conclusions 1:55[q5]. The value of this study is demonstrating feasibility and perfect concordance in a small series — the foundation for a multicenter validation trial.

The distinction between image-guided dissection and sentinel node strategy matters. Using radiotracer to locate nodes that would otherwise be difficult to identify is helpful regardless of whether you remove all nodes or only the sentinel [q5]. But the transformative potential is in selective sampling: if the sentinel node reliably predicts nodal status, you avoid the morbidity of full dissection in node-negative patients 3:26. That requires proving the technique works across institutions, tumor sizes, and histologic subtypes before it changes the standard of care.

The endpoint is not whether sentinel nodes can be found, but whether finding them changes what you remove. Every patient in this series underwent complete lymph node dissection after sentinel node identification 3:10, which is the only way to calculate false negative rate. The next phase would be a registry trial where multiple centers use identical radiotracer protocols and report both sentinel node findings and full dissection pathology 1:55. Only when that dataset is large enough to define the false negative rate with narrow confidence intervals does the question of selective sampling become answerable. Until then, the technique remains investigational — useful for locating nodes, not yet validated for limiting dissection.

Takeaways from this story

100% false negative value means perfect negative prediction — when sentinel node is negative, no other nodes are positive.
Radiotracer injection at surgery start identifies sentinel nodes in aortic cable space, making dissection easier even before considering selective sampling.
Twenty patients establish feasibility but cannot define false negative rate precisely enough to abandon full lymphadenectomy in Wilms tumor.
Multicenter collaboration with identical radiotracer protocols is required to generate validation cohort large enough for practice change.

Topic overview

This podcast reviews two articles from the August 2022 Journal of Pediatric Surgery, selected by Dr. Pablo Laje. The first article from Iran examines sentinel lymph node biopsy in pediatric Wilms tumor, finding a 100% negative predictive value in 20 patients with no false negatives detected. The second article from New York describes ECMO complications in CDH patients, reporting that 21% of 258 CDH patients required ECMO support with 61% survival, and up to 70% of those on ECMO experienced complications, most commonly metabolic and mechanical.

Key takeaways

Sentinel lymph node biopsy in pediatric Wilms tumor showed 100% negative predictive value with no false negatives in 20 patients. (3:10)
21% of CDH patients required ECMO support with 61% survival; up to 70% experienced complications, most commonly metabolic and mechanical. (5:31)
Mechanical and renal complications on ECMO were more common among CDH non-survivors, suggesting prognostic significance. (5:40)
Radiotracer injection around Wilms tumors enables easier identification and removal of sentinel lymph nodes, most commonly in aortic cable space. (2:39)

Keywords

Wilms tumor CDH congenital diaphragmatic hernia sentinel lymph node biopsy ECMO lymph node dissection radiotracer injection Cincinnati Children's Hospital Children's Hospital of Philadelphia Akbar Children's Hospital Mashhad University of Medical Sciences

Hashtags

#WilmsTumor #PediatricSurgery #ECMO #CongenitalDiaphragmaticHernia #SentinelNode

Transcript

Click "Show Transcript" to view the full text (6293 characters)

Hi, everyone. Welcome back to the Stay Current podcast. As you know, here at Cincinnati Children's Hospital, we dedicate to summarize what's most important out there, and for that, we have a couple of articles in the Journal of Pediatric Surgery to highlight for you. Along with the infographic, we have posted on social media and on the app. We're gonna talk about that article as well as another one here. As a reminder, I'm Ellen Ancisco. I'm Anton Bash, and I'm Cecilia Guica, and we're research fellows at Cincinnati Children's Hospital Medical Center, and this is part of our series again on highlighting Journal of Pediatric Surgery articles. As usual, the editors helped us pick the articles. This month, the month of August 2022, was chosen by Doctor Pablo Laje, a pediatric surgeon at Children's Hospital of Philadelphia. And the two articles we're gonna talk about today. One is about sentinel lymph node biopsy and Williams' tumor, and the other is about complications, a description of, you know, some complications that occur in newborns needing ECMO for CDH. And so, do you want to take it away with the first one, M? Yeah, of course. Our first article for today is uh coming from Iran. Uh, it's called Sentinel Lymph node Biopsy in Pediatrics Wilms tumor. We talked with the 2nd and 3rd author, Doctor Shojaan and Doctor Hirafar. I'm Doctor Reza Shojayan, uh, associate professor of Akbar Children's Hospital, Mashhad University of Medical Sciences. My name is Mehran Hiraw, and I also, uh, I'm a pediatric surgeon and work in the same center that Dr. Shujayan worked there as an associate professor of pediatric surgeon. This is a prospective study to see if we can use sentinel lymph node biopsy for diagnosing and staging pediatric bones tumor. They recruited 21 to 16 year old children with non-metastatic primary wilms tumor. We started with the same protocol as the other solid tumors, which is the injection of radio tracer around the tumor at the first step of the surgery. And searching for the maximum uptake in tumor region. The sentinel lymph node detection and sampling was made with the radio tracer. According to the results, for 16 patients, They found one, just a single sentinel lymph node, and 4 of them have more than one, and they have, they had multiple sentinel lymph nodes and the most common site where those lymph nodes were aortic cable space. How well did the sentinel node correlate with the node that was actually the positive node? And that was Dr. Tal Ponsky. He's a pediatric surgeon at Cinna Children's Hospital. We didn't find any positive lymph node. Among those patients. That sentinel node was negative. So this makes the false negative value of this method 100%. The false negative means that none of the patients who had no tumor in the sentinel lymph node had tumor elsewhere. If they had tumor elsewhere, then it was also in the sentinel lymph node. And here's some comments from Doctor Gatfar. And this techniques, I think, helped the surgeon to, to find and remove and pick it up the lymph node very easily. Is this just another form of image guided surgery? You inject the tracer and it shows you where the nodes are, because sometimes it's hard to see them. Even just that is helpful. Yeah, but eventually, if you're 100% sure that it's the sentinel node's negative and then the rest is negative, you can just take out the sentinel node, send it to pathology, and wait for them to tell you it's negative, OK, this is like the ending of the surgery. That's a great point, Cecilia. Maybe in the future, we won't need to do this full lymph node dissection for Wilms as we found in other Pathologies or in other diseases, but this is one step perhaps towards that. I think that a collaboration between other centers on similar methodology will help everybody to come to a conclusion soon. Yeah, maybe that would be one of the next steps that can be taken if anyone out there reading your paper, maybe they can reach out to you and plan a collaboration between different centers. Yeah, OK, so we have the second article for today that's called ECMO and it's Complications in Urus or CDH. Uh, what they did, this is a study made in New York, and what they did is describe the complications among the patients with, uh, CDH that had ECMO and they presented the complications with the ELSO criteria, so it's pretty standard. That was Dr. Lahey. He, he helped us to choose his articles from JPS August issue, and they had 258 patients with CDH. Of them, 21% were supported with ECMO, and from the ECMO patients, 61% survived. The most common categories of complications were metabolic and mechanical, but two categories from the complications that were more common among non-survivors were mechanical and renal complications. The conclusion is that up to 70% of CDH patients that go on ECMO have complications, but as they said somewhere along the way, you know, not, not all complications. are equal and not all complications are equally relevant for us as surgeons, right? Yeah, I think it's, you know, it's more, um, educational than practice changing. It's like Doctor Lahe said, it's, you know, important to understand the complications that can come from any procedure that we do, and this is, you know, educational or descriptive information like you said. It's good for us to keep learning more about this disease and better understanding and predictors of outcomes, so we can tailor our care in the future, but, um, you know, They've always been a, uh, you know, one of the leading centers in, in this, and it's good to have them give us their updates every now and then, so that's great. OK, so that was the 2nd part of our August podcast. Again, the first article we talked about is featured in an infographic posted on social media and on the app, and both articles are linked below if you want to read them for yourself and get all the details. Thanks for listening. If you liked what you heard, be sure to leave us a comment and a rating and a review wherever you're listening, wherever you're watching. Uh, don't forget to download the Stay Cre and Pediatric Surgery app, see the infographics, see more of these podcasts. Again, I'm Ellen and Cisco. I'm I'm Tom Bash, and I'm Cecilia Geno, and this is just a current podcast.

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