Colorectal Quiz Episode 14: ARM Newborn Part 3

Published: 2021-06-21

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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

Amanda Jensen — host
Rod Gerardo — host
Doctor Levitt — guest
Doctor Fisher — guest

Chapters

0:00Introduction and Series Context — Hosts introduce the final episode of a three-part series on ARM newborn examination, directing listeners to previous episodes and the Stay Current app for associated images.
1:12Cross-Table Lateral Imaging Interpretation — Discussion of cross-table lateral (crossfire) radiographs showing rectal gas columns at different distances from the anticipated anal opening, with decision-making regarding primary repair versus colostomy based on these measurements.
4:10VACTERL Association and Prognostic Factors — Review of systematic evaluation for associated anomalies using the VACTERL acronym and discussion of how malformation type, sacral ratio, and spine status predict continence potential.
5:43Surgical Approach Selection — Discussion of primary anoplasty technique variations based on fistula location within the sphincteric complex, emphasizing posterior-only mobilization to avoid urethral injury when the fistula is anteriorly located.
7:59Joke and Episode Summary — Colorectal joke about a fish with prolapsed cloaca, followed by episode recap covering physical exam findings and decision-making for colostomy versus primary repair.

Key claims

1:16Cross-table lateral film (also called crossfire film) is obtained by placing baby prone in NICU — Doctor Levitt
1:23Cross-table lateral is the modern version of the old-fashioned invertogram — Doctor Levitt
1:49Cross-table lateral films should be obtained around 24 hours after birth when no fistula is evident on exam — Doctor Fisher
2:06When air column stops at about the 4th sacral vertebral body with large distance to sphincter marker, colostomy with distal colostogram is indicated — Doctor Fisher
2:49When air column is very close to anticipated anal opening location, primary anoplasty can be considered — Doctor Fisher
3:30Image showing air column far from sphincter is almost definitely a rectal urethral fistula worthy of colostomy — Doctor Levitt
3:39Image showing air column close to sphincter is probably a perineal fistula or no fistula, potentially suitable for primary repair, but must be careful of low bulbar fistula — Doctor Levitt
4:24VACTERL acronym stands for: Vertebral, Anorectal, Cardiac, Tracheoesophageal fistula, Renal, and Limb — Amanda Jensen
4:46For every ARM patient, must know: type of malformation, quality of sacrum, and quality of spine — Doctor Levitt
4:46High malformation, poor sacrum, poor spine predicts poor continence potential — Doctor Levitt
4:46Low malformation, normal sacrum, normal spine predicts good potential for bowel control — Doctor Levitt
5:12PCPLC consortium is collecting data across 15 centers to predict continence outcomes based on malformation type, sacral ratio, and spine status — Doctor Levitt
6:13Decision for primary anoplasty versus colostomy depends on surgeon comfort level and institutional post-operative care capabilities — Doctor Fisher
6:35When fistula opening is in the northernmost part of sphincteric ellipse in males, posterior rectal wall only mobilization should be performed — Doctor Levitt
6:57Avoiding anterior wall mobilization removes the major complication risk of urethral injury — Doctor Levitt
7:09Posterior-only mobilization technique applies only when fistula dot is within the sphincteric ellipse — Rod Gerardo
7:16The common wall between rectum and urethra is closer and longer than many people anticipate — Doctor Fisher
7:29For fistula in sphincter but in most anterior portion, anterior rectal wall does not need to be touched during dissection — Doctor Levitt
7:41When no obvious fistula is present at 24 hours and cross-table lateral does not show distal air column, colostomy is needed — Doctor Fisher

Open questions

What is the precise predicted continence percentage for specific combinations of malformation type, sacral ratio, and spine status (data collection ongoing through PCPLC consortium)

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:

Cross-Table Lateral Radiography and Surgical Decision-Making in Newborn Anorectal Malformations

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 trainees · Teaching arc · AI-written, human-reviewed

Radiographic Technique and Timing

The cross-table lateral film replaces the invertogram. The baby is placed prone in the NICU and a lateral X-ray is shot to visualize the rectal air column 1:16. This is the modern version of what was once done by inverting the infant 1:23. The film should be obtained around 24 hours after birth when no fistula is evident on physical examination 1:49. The 24-hour timing allows sufficient air to reach the distal rectum, making the distance measurement meaningful.

Reading the Film for Surgical Planning

Distance from air column to sphincter marker determines the approach. When the air column stops at approximately the 4th sacral vertebral body with a large distance to the sphincter marker, the malformation is high — almost certainly a rectourethral fistula requiring colostomy with subsequent distal colostogram 2:06 3:30. When the air column is very close to the anticipated anal opening location, you are likely dealing with a perineal fistula or no fistula, and primary anoplasty becomes a reasonable consideration 2:49 3:39. The caveat: even with a seemingly low lesion, you must remain alert for a low bulbar fistula 3:39.

Prognostic Assessment Beyond the Malformation

Three factors predict continence potential: malformation type, sacral quality, and spine quality. For every ARM patient, these three elements must be documented 4:46. High malformation combined with poor sacrum and poor spine predicts poor continence potential 4:46. Low malformation with normal sacrum and normal spine predicts good potential for bowel control 4:46. The VACTERL screening (Vertebral, Anorectal, Cardiac, Tracheoesophageal fistula, Renal, Limb) provides the systematic framework for identifying associated anomalies 4:24. The PCPLC consortium is now collecting data across 15 centers to build predictive models based on malformation type, sacral ratio, and spine status 5:12 — work that will eventually allow quantitative prognostication for family counseling.

Surgical Technique for Low Fistulas Within the Sphincter

Posterior-only mobilization eliminates the major complication risk. When the fistula opening is located in the northernmost (anterior) part of the sphincteric ellipse in males, perform posterior rectal wall mobilization only 6:35. By avoiding anterior wall mobilization entirely, you remove the major complication risk of urethral injury 6:57. This technique applies specifically when the fistula dot is within the sphincteric ellipse 7:09 — if the fistula is in the sphincter but in the most anterior portion, the anterior rectal wall does not need to be touched during dissection 7:29. The anatomy that makes this approach necessary: the common wall between rectum and urethra is closer and extends longer than many surgeons anticipate 7:16.

The Judgment Call

Surgeon comfort and institutional capabilities matter. The decision between primary anoplasty and colostomy depends on the surgeon's comfort level and the institution's post-operative care capabilities 6:13. When no obvious fistula is present at 24 hours and the cross-table lateral does not show a distal air column, colostomy is needed 7:41. The radiograph provides data, but the surgeon must integrate that data with their own experience and their institution's resources. A colostomy is always a safe answer when operating on a newborn in this situation makes you uncomfortable.

Takeaways from this story

Cross-table lateral at 24 hours guides colostomy vs primary repair: air at S4 with large distance to marker means colostomy.
Document malformation type, sacral quality, and spine quality for every ARM patient—these three factors predict continence.
When fistula is in anterior sphincter, mobilize posterior rectal wall only to eliminate urethral injury risk.
The rectourethral common wall is closer and longer than anticipated—critical anatomy for avoiding urethral injury.

Cross-Table Lateral Radiography in Newborn Anorectal Malformation: When to Repair, When to Divert

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 Imaging Exists

Anorectal malformations present at birth with a spectrum of anatomic variants, and the initial decision—primary anoplasty versus colostomy—hinges on knowing where the rectal pouch terminates relative to the perineal sphincter complex. When physical examination at 24 hours fails to reveal a fistula, cross-table lateral radiography provides the anatomic roadmap 1:49. This imaging replaced the invertogram, which required suspending infants upside down; the modern technique simply positions the baby prone in the NICU for a lateral X-ray 1:16 1:23.

The Core Clinical Problem

The rectal pouch's distance from the anticipated anal opening determines surgical feasibility and risk. A high pouch—terminating at the level of the fourth sacral vertebra with a large gap to the sphincter marker—almost certainly represents a rectourethral fistula and warrants colostomy with delayed definitive repair 2:06 3:30. A distal air column very close to the perineal marker suggests a perineal fistula or no fistula, making primary anoplasty technically feasible, though a low bulbar urethral fistula remains a diagnostic trap 2:49 3:39.

The stakes are concrete: operating on a high malformation as if it were low risks urethral injury during dissection; diverting a low malformation that could be repaired primarily subjects the infant to an unnecessary colostomy and second operation.

How the Approach Works

Cross-table lateral films are obtained around 24 hours after birth when no fistula is evident on examination 1:49. The radiograph shows the rectal gas column's termination point. Interpretation is straightforward: measure the distance between distal rectal air and the radiopaque marker placed at the anticipated anal site. When that distance is large—air stopping around the fourth sacral vertebra—colostomy with subsequent distal colostogram is indicated 2:06. When the air column reaches the perineal marker, primary repair becomes an option 2:49.

But feasibility is not the same as mandate. The decision for primary anoplasty versus colostomy depends on surgeon comfort and institutional postoperative care capabilities 6:13. A colostomy is always defensible when uncertainty exists. When no distal air column appears at 24 hours and no fistula is evident, colostomy is required 7:41.

Surgical Technique Variation by Fistula Location

When primary anoplasty is chosen, fistula position within the sphincteric complex dictates dissection strategy. For males with a fistula opening in the anterior—northernmost—portion of the sphincteric ellipse, posterior rectal wall mobilization alone is performed 6:35. Avoiding anterior wall dissection eliminates the major complication risk: urethral injury 6:57. This posterior-only technique applies specifically when the fistula is within the sphincteric ellipse 7:09. The common wall between rectum and urethra is closer and longer than many surgeons anticipate, making anterior dissection hazardous in these cases 7:16 7:29.

Prognostic Context

Beyond the immediate surgical decision, three factors predict long-term continence potential: malformation type, sacral quality, and spine quality 4:46. High malformation with poor sacrum and spine predicts poor continence; low malformation with normal sacrum and spine predicts good bowel control 4:46 4:46. The VACTERL association—Vertebral, Anorectal, Cardiac, Tracheoesophageal fistula, Renal, and Limb anomalies—requires systematic screening in every case 4:24. The PCPLC consortium is collecting data across 15 centers to generate predictive models based on malformation type, sacral ratio, and spine status, aiming to provide families with quantitative continence predictions 5:12.

When to Involve Colorectal Surgery

Any newborn with imperforate anus requires immediate colorectal surgical consultation. The cross-table lateral at 24 hours is a decision point, not a screening tool—by the time it is obtained, the surgical team should already be involved. Referring clinicians should recognize that absence of a visible fistula at 24 hours is an indication for imaging and surgical planning 1:49. The physical examination findings in the first day of life—presence or absence of meconium at the perineum, fistula location if visible—guide the urgency and type of imaging, but the surgical team owns the interpretation and operative decision.

Takeaways from this story

Cross-table lateral at 24 hours guides repair vs. colostomy: large gap to sphincter marker indicates diversion; close proximity allows primary repair.
Posterior-only rectal mobilization when fistula is anterior in sphincter eliminates urethral injury risk during primary anoplasty.
Malformation type, sacral quality, and spine status predict continence potential—high lesion with poor sacrum/spine forecasts poor outcomes.
The rectourethral common wall is closer and longer than expected; anterior dissection in males with anterior fistulas risks urethral injury.

Cross-Table Lateral Radiography to Guide ARM Surgical Decision-Making

The essential version of this episode — what it covers, the points that matter most, and what it changes for you. Written by Kai from the episode transcript and reviewed before publishing.

For specialists · Core brief · AI-written, human-reviewed

Radiographic Technique and Timing

The cross-table lateral film (crossfire film) is obtained by placing the baby prone in the NICU 1:16. This modern technique replaces the invertogram 1:23. When no fistula is evident on exam, obtain the film around 24 hours after birth 1:49.

Decision Thresholds for Primary Repair vs Colostomy

When the air column stops at approximately the 4th sacral vertebral body with large distance to the sphincter marker, proceed with colostomy and distal colostogram 2:06. When the air column is very close to the anticipated anal opening location, consider primary anoplasty 2:49.

Doctor Levitt interprets an air column far from the sphincter as indicating almost certainly a rectal urethral fistula requiring colostomy 3:30. An air column close to the sphincter suggests probably a perineal fistula or no fistula and potentially suitable for primary repair, though low bulbar fistula remains in the differential 3:39.

Doctor Fisher emphasizes that the decision depends on surgeon comfort level and institutional post-operative care capabilities 6:13.

Posterior-Only Mobilization Technique

When the fistula opening is in the northernmost part of the sphincteric ellipse in males, perform posterior rectal wall mobilization only 6:35. Avoiding anterior wall mobilization removes the major complication risk of urethral injury 6:57. This technique applies specifically when the fistula dot is within the sphincteric ellipse 7:09. Doctor Fisher notes that the common wall between rectum and urethra is closer and longer than many anticipate 7:16, making this approach particularly relevant.

Prognostic Assessment

For every ARM patient, determine three factors: malformation type, sacral quality, and spine quality 4:46. High malformation with poor sacrum and spine predicts poor continence potential 4:46. Low malformation with normal sacrum and spine predicts good bowel control potential 4:46. The PCPLC consortium is collecting data across 15 centers to generate predictive models based on malformation type, sacral ratio, and spine status 5:12.

Management Without Evident Fistula

When no obvious fistula is present at 24 hours and the cross-table lateral does not show distal air column, colostomy is indicated 7:41.

Takeaways from this story

Air column at 4th sacral vertebra with large sphincter distance indicates colostomy; close proximity suggests primary anoplasty feasibility
Posterior-only rectal mobilization when fistula is in anterior sphincteric ellipse eliminates urethral injury risk
Malformation type, sacral quality, and spine quality together predict continence potential in ARM patients
The rectourethral common wall extends closer and longer than commonly anticipated during dissection

Topic overview

This episode concludes a three-part series on newborn examination for anorectal malformations (ARM), focusing on imaging interpretation and surgical decision-making when perineal exam does not reveal fistula location. The discussants review cross-table lateral radiographs to determine the distance between rectal gas and the anticipated anal opening, using this measurement to guide decisions between primary anoplasty and colostomy creation. They emphasize the importance of systematic evaluation for VACTERL-associated anomalies and discuss how malformation type, sacral quality, and spine status predict continence outcomes.

Key takeaways

Cross-table lateral films at 24 hours help distinguish high vs low ARM: air column near sacral marker suggests primary repair feasibility
High fistula (air stops at S4) warrants colostomy; low fistula (air near anticipated anus) may allow primary anoplasty in experienced hands
VACTERL screening is mandatory: vertebral, anorectal, cardiac, tracheoesophageal, renal, limb anomalies affect surgical planning
Continence prediction requires three factors: malformation type, sacral ratio, and spine quality—data from multi-center consortia will improve counseling
Primary anoplasty decision depends on surgeon comfort and institutional postoperative care capacity, not just imaging findings

Keywords

anorectal malformation rectal urethral fistula perineal fistula low bulbar fistula cloaca VACTERL association cross-table lateral radiograph crossfire film invertogram colostomy distal colostogram primary anoplasty posterior sagittal anorectoplasty posterior rectal wall mobilization Cincinnati Children's

Hashtags

#AnorectalMalformations #PediatricSurgery #ColorectalSurgery #NewbornCare

Transcript

Click "Show Transcript" to view the full text (8966 characters)

Hey there listeners, it's Amanda Jensen and Rod Gerardo from Cincinnati Children's. Have you downloaded the new version of the Stay Current pediatric surgery app? It's in the Apple App Store, it's in the Google Play Store. The reason we bring it up is because this podcast has a bunch of associated images, and all of the images are in the app that you can bring up in real time while Doctor Fisher and Doctor Levitt are talking about them. So download the app today, but in the meantime, enjoy the colorectal quiz. Spoiler alert, this episode is the last of our 3-part series on the newborn exam for anorectal malformations. So if you haven't heard the 1st 2 episodes, stop this episode right now. Hit pause, get out of this episode, go listen to the last 2 episodes of the Colorectal quiz. If you've been keeping up every week, Amanda, give us a quick summary. We discussed the variations in physical exam findings in both the female patient and the male patient. Then we left it with a cliffhanger. We had a patient where the perineal exam did not reveal where the fistula was. So, what did they do? They got some imaging. What kind of imaging, you ask? Well, here's Doctor Levitt from Children's National Hospital. This photo, uh, there are actually two photos, one side by side. Um, are what, um, we would call a crossfire film, also known as a cross table lateral film. Well, the old fashioned version of this was an invertegram. Uh, this baby just needs to be placed prone in the NICU and a crossfire X-ray is, is shot. Um, and the there's an image on the left, and there's an image on the right, and both of them show a nice air column. So, what say you? What say me? Well, I think that's Doctor Fisher from Cincinnati Children's. The importance of this is you could get this film early, and then also get this around 24 hours later. These are different patients. It's 24 hours, and there's no evidence of a fistula on exam. How do you decide between primary repair and colostomy? So, always the safe answer is if you're uncomfortable operating on the newborn, In this situation, a colostomy is certainly in the books, but if you look at the film on the left, the air column stops at about the 4th sacral vertebral body, give or take a little bit. And so, what, and you could see where the marker is or the BB is, uh, where the, where the sphincter complex appears to be located. There's a large distance between those. And so for me Me, this is a patient that I would be diverting, considering diversion, and doing a distal uh cholostogram to really delineate that, that anatomy. All right. How about the image on the right? So, the air column is very close to where the anticipated anal opening should be located. And this is a case where you could take your barley bush, potentially, and make a nick, uh, a scratch, and, and do your anoplasty. I really like that joke because it's a callback to part one. From like 2 weeks ago. So if you haven't heard it, you gotta go back and you gotta listen to that episode. Or if you're practicing in the 21st century, you might wanna take them to the operating theater and maybe do a formal posterior sagitin or rectoplasty. I don't think barley comes in the form of a bush. All right, guys, come on, let's refocus. I agree. I think the one on the left is almost definitely a rectal urethral fistula, um, worthy of a colostomy. That's what I would do based on this image. Um, and the one on the right is probably almost a perineal fistula or a no fistula, and I would be, um, inclined to potentially do that one primary, but you gotta be careful cause you might be dealing with a low ball bar fistula. Why am I getting deja vu all of a sudden? That was our first podcast, I believe. Well, I mean, it's, it all comes full circle at some point, doesn't it? It sure does. Um, if you don't have a good memory, then it's all brand new. OK, let's get back to the subject here. This is probably a good time to reiterate that you should have a systematic way. To rule out any other associated anomalies. And it's very well represented by the acronym Val. Amanda, really quick, what's Vactoral? V is for vertebral, A for anorectal, C for cardiac, T and E for trachoesophageal fistula, R for renal, and L for limb. Piggybacking off of that multiple times on this podcast, we've talked about what you need to know for every patient who has an anorectal malformation. We should always know the type of malformation we're dealing with, the quality of the sacrum, and the quality of the spine, high malformation, poor sacrum, poor spine, not good continence potential, low malformation, normal sacrum, normal spine, good potential for bowel control, and obviously a lot of gradations in between. And I hope one day we have real good predictions based on this data. And that's one of the values, a little shout out to the consortium, the PCPLC that is calculating all of this stuff across now 15 centers, and then one day, we're gonna actually be able to tell you, if your malformation is X and your sacral ratio is Y, and your spine status is Z, your predicted continence is 82%. Imagine the power of that uh data one day. Definitely will be helpful for counseling families, no question about it. Can't wait for that data to come out and be able to use it for families. Let's move on in the podcast. Let's talk about surgical approaches to do that. Open up the next image under your media player. We see that similar image to the perineal fistula. This time, the beads of mucus are there, they're not black, they're white. And the air column is super close. Would you go for a primary oplasty in these two cases or a colostomy? I think, I, I think that's up to the individual surgeon. I think there's certainly a role for doing a primary anoplasty in these patients. It's a matter of level of comfort, a matter of level of how the post-operative care in your institution might be for these patients. So, certainly, it's A possibility and something I would consider. You see the picture on the left with the little bead of white, the white dot. I see that white dot is in the sphincter, but in the northernmost part of the sphincteric ellipse. And this is the kind of case in a male that I would do a posterior rectal wall only mobilization. And I would avoid any anterior wall mobilization at all. Therefore, removing the one major complication that you're always worried about, and that is a urethral injury. But to be clear, that's only in situations like this where the dot of the fistula is in the sphincteric ellipse. I think people don't realize that common wall or, or that wall between the rectum and the urethra is a lot closer and a lot longer. Of a common wall, then I think some people anticipate. A hole that's in the sphincter, but just the most anterior portion of it, you do not need to dissect. You don't even have to touch the anterior rectal wall. All right, let's look at the last image. But there's no obvious fistula happening and it's 24 hours. I think you would agree this is a patient that needs a colostomy. Yup, this again, we would get our cross table or crossfire lateral, but assuming we don't see an air column very distal, an obvious colostomy is needed here. And now, the colorectal joke of the day. So, can I tell you a story, Mark? I have many, many memories working with you and learning from you. One of them is you had a photo in your office, and I don't know if you still do, of a fish you caught. It it's true, the fish has one opening. Yes, by definition, all fish, all fish, but you have a one with a prolapsed opening, therefore accentuating, accentuating the situation, and therefore, you know, symbolizing a cloaca. So what did that fish say when it swam into a wall? Um, could it be? Damn, damn, you got it. How do you know? You're too smart. It's funny, you know, most people don't believe me when I show that picture, but I actually caught that fish. I actually caught the fish with the prolapsed cloaca, um, and then I, um, quickly did a, um, little anoplasty and returned the fish to the water. Yeah, it's wonderful. Yeah, it was, uh, you know, it was impressive use spinal anesthesia for that. All right, if you're waiting for the case report on that operation, don't hold your breath. But that's a wrap on the anorectal malformation newborn perineal exam. I hope you enjoyed all three parts of this short series in the colorectal quiz. Amanda, give us a summary. So, just to go over part one and part two, we discussed the physical exams of both the female and male newborn with an anorectal malformation. And in this episode, we discussed uh what to look at on that uh cross-lateral film and decision making around a colostomy versus a primary repair. Thank you so much, Amanda, and I hope you guys enjoyed the episode. Make sure you download the State Current Pediatric Surgery app. I'm Rod and I'm Amanda Jensen from Cincinnati Children's. Remember, knowledge should be free.

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