C (8:30)
Did I do that? The truth is, that's not what the data show. So even when you stratify for trainee level, now I'm telling you in general, yes, obviously on a case by case issue, you know, wrong technique, a lack of experience that totally contribute to to uterine hysterectomy extension. Especially if you flex your wrist when you're trying to get that head out. I hate that I always tell them keep your wrist still. So yes, I get there are individual cases because this happened to me. But in general, the body of the data, and we'll get into this in a minute, does actually not show that that it doesn't really matter based on level of training. If you stratify based on the other issues, like why you're doing this section to begin with, especially if it's a very thin lower uterine segment, like with a deeply impacted fetal head stuck in a protracted second stage of labor. That is the big risk factor for hysterotomy extension, not just throwing the intern or the resident or the fellow under the bus. Okay. So yes, let's get back to this publication. Interesting timeline, right? 2018, 2020, 2024, and this one in 2026. Yes, this is a narrative review, basically. Think of it as a peer reviewed mini research paper. And it's good. I mean, there's some really good information in this. If somebody ever asks you about the incidence of a hysterotomy extension, again, unintentional. We're not talking about the bandage scissor, you know, cut. Because of an issue. This is a. Oh man, I lacked the hysterotomy and I have a little, you know, inferior extension. The rate is, the answer is yes. Okay? And it's yes because it's all over the place and it varies mainly by the indication for the C section. I mean, some have said it's under 1%. Like 0.7 others have said, oh, no, man. If it's a deeply impacted fetal head, you gotta put your hand way down there. You gotta dislodge whether it's push or pull, whatever. That can be as high as 14%. So what is the incidence of unintended hysterotomy extension? Yes, it's there and it's broad. A lot of different numbers because you can't just group it all as one occurrence because it really does vary based on the indication of C section. Now, we're gonna talk about risk factors before we get to our main question of does this affect tolac? Would you let a patient who's had an unintentional hysterectomy extension, mainly inferior. Would you let them tolac? We're gonna get into it now. It's very unusual to have a superior lack. Those are usually with banded scissors, and those are intentional. Most of these lacks are lateral wall ligament, which are a problem because those bleed. So you gotta be very cautious of those. Or they're down inferior, close to the vaginal fornix, which, again, those bleed. And those are the ones that give you concealed bleeding down by the inner thighs because blood's going down and you can't see down there. All right, you gotta make sure you get to the edge. Get to the apex and don't take wide bites down there because ureter is down there. Okay? So be very, very careful. Just grab what you need. Evert the edges and get the edges and close them together. I do them as interrupted when it's down by the vagina. I don't like to do a runny. I think it traps too much tissue. But you got to do what you got to do. Okay? Now, figure of eight also works very nicely. So we're going to talk about risk factors. But here's a good clinical pearl. Again, we're about to enter summer. This is good for those getting ready to do their oral boards in the fall. The number one, the big risk factor for a unintended hysterotomy extension is not level of training of the surgeon. It's not prior history. That's not a thing. It is second stage of labor across a variety of studies, whether they've been prospective retrospective meta analyses. That's the answer, guys. Doing a C section in a patient who is stuck, that kid ain't coming out. Usually because of failure to descend or asynclotism. That second stage C section is the single most important and most powerful independent predictor of unintended hysterotomy extension. So what I tell our residents or our intern, hey, this kid is not coming out. She's been pushing for two hours. It is deeply wedged. We're going to try to break that vacuum seal without using a vaginal hand. We don't do a fetal pillow. We're going to try to use our hands to do this. In the worst case issue, if it's just not coming, then I'll just grab the feet and do a reverse breach. But do not flex your wrist because that second stage lower uterine segment is so paper thin that any wrong angle can increase the risk of an unintended hysterotomy extension. So that is the issue. Guys, there was an Israeli paper that looked at this. This was a single center retrospective evaluation, and they said, listen to this number, guys, Again, single center. The odds ratio for an extension with a second stage C section was 54. That's 5, 4 as an odds ratio, 54 times more likely. Now, it doesn't mean it's going to happen. It just means that if you have a baseline astronomy rate that's pretty low for an extension, it's 54 times that. Okay, now that's a big, big number. And of course, as we've already mentioned, the big confounding factor there is not just second stage. It is a deeply impacted fetal head at the second stage. Now, if you're at your oral boards and your, you know, your oral board examiner says, well, is it second stage duration or what exactly is it in the second stage? Here's where you go, yes, sir. Yes, ma'. Am. Second stage is the single most important and powerful risk factor for an unintended hysterotomy extension. But it's actually not just the length of the second stage. It's probably that wedging that head down into the pelvis and that continued pressure of the fundus that thins that lower uterine segment. Okay, so this has been looked at. So it is a deep impacted fetal head where that lower uterine segment is just so worn out that is the biggest risk in the second stage of a hysterotomy extension. So, second stage for sure. But as a sub caveat of that, on sub analysis, it's not just the length of the second stage. It's actively pushing. In other words, it's thinning out that lower uterine segment as a, you know, fund is kind of hypertrophies to work it out, and it's just not falling. That's the biggest risk. So second stage of labor. Absolutely. But it's not duration, it's active pushing. And the reason that we can say that is there have been studies that look at just, you know, passive descent, not pushing. Although, again, that's not what we're supposed to do. Right. We're supposed to do active pushing at 10 centimeters. But those that did not do that, and they're like, man, you just ran out of time period. I mean, we're just done because you chose not to push. And we're at three hours or four hours max, based on whatever her GS and Ps are, with or without an epidural, like, we're just done. We're gonna get out. There's been no descent. That actually does not raise the risk as much as if there was active pushing. So it's the mechanics of active pushing, the extra thinning of, of the lower uterine segment and then wedging that head down that matter. All right, so second stage of labor. Absolutely. But pushing in the second stage, in addition to the length of time as a composite, both of those are big risks. Now, as we mentioned, this whole issue of blame the intern. I would love to do it, I really would, and you can do whatever you want to do, but no, it just, you know, thankfully really doesn't seem to be the case. So according to this review, quote, there has been no observable difference when comparing surgeries led by junior residents as opposed to senior residents or even attending level surgeons. End quote. My attending ego would like to say otherwise, but the data is what it is now, of course, now you can show me. I know you're going to pull out some study that says, ah, lower level trainees much more likely to do it. I get that, man. Yes, they are out there. That absolutely true. But not the weight of the evidence says level of trainee. Once you stratify as a confounding factor for indication, probably not a thing. Okay, but there was one study, it was an academic study out of France that said that the odds of an unintended hysterotomy extension were actually higher when a fellow did it. Now remember, this is advanced training. It's not the U.S. but still, it's advanced training. But it was higher when a fellow did it compared with an attending as an assistant professor or associate professor, somebody who's, you know, done with their residency and or fellowship. So that one did show a change in hysterotomy rates or odds ratios based on level of training, as it will always be one. But the whole body of the evidence probably doesn't really say that. There's a clear association between that once you stratify for why the section was done. Okay, again, I want to talk about a couple of things here for the morbidity as we start easing into the issue of the biggest morbidity, which is uterine rupture at subsequent tolac. The first, we all get it. The most common morbid outcome of some kind of hysterotomy extension is what? Kids, kids, come on. It's bleeding. Duh. I mean, we're gonna get into the broad ligament, we're gonna get down into the perivaginal vessels for sure. And by the way, this is something else that this new publication does. It tries to propose, and I like it. It's fine. You know, a kind of a grading system of extensions or, you know, grade one, two and three based on, you know, the depth based on size of penetration and where it is lateral, you know, inferior lateral extension or straight down inferior. And that's fine. I don't have a problem with that. I just think it's much better and much clearer to just say where it is. There was a 2 centimeter lateral extension on the right or on the left that did or did not include, you know, the branches of the uterine broad ligament was intact. I mean, I say exactly, and I tell the residents, I want you to say this so the next person who's reading this knows exactly what happened. If it's inferior, there was a 2 to 3 centimeter directly inferior. And I give them a clock, you know, direction, directionality. It's at 7 o', clock. It did not extend, you know, beyond the internal cervical ring, which I palpated. So it's a very clear description of this map. And so you can do a grade. The problem is right now, there's no universal grading of these extensions. So everyone's going to have a different scale. I just think if you do a good description, I think it's fine. But there's no question, the bigger the extension and the more lateral it is, of course, into the blood vessels or the further down it is into the vagina because the vagina bleeds. Surprise. Those increase the risk for bleeding. Preterm birth. Yes, we've mentioned it. That's a big clinical pearl that even here it is, guys. In the absence of any kind of extension, women who undergo a second stage C section do have a. A higher risk of spontaneous preterm birth than those who had a C section for failure to progress in the first stage. Okay, so it's Not a C section overall. And be very clear, it's not having a C section that increases your risk of preterm birth. It seems to be a C section in the second stage. Probably for the same factors that we've already discussed. They need a lowering segment, maybe some scar tissue down there, maybe something with cervical signaling, whatever. So it's not just having a C section. It's a C section in the second stage that does increase the risk. Bumps it a little bit, doesn't mean it's going to happen, but it just. It's a bump in the odds ratio for subsequent preterm birth. However, don't forget that this is not applicable to vaginal birth. Okay. So even if a patient has a prolonged second stage, there's been no increased rate of preterm birth after vaginal delivery, even with a prolonged second stage. So second stage, that's long, but vaginal, that's a separate issue. This is second stage that's prolonged and then gets a section. Yes. That has a slight bump in preterm birth risk. So patients need to know that. Okay. That's why it's important, as I tell the residents to document what happened, why that indication for C section is super important. This is a second stage C section after pushing for three hours with a deeply impacted fetal head at this station, be as descriptive as possible. So two or three years down the road, when somebody's reading that, they're like, oh, okay, I dig it. All right, I'm gonna watch for now preterm labor because it was a C section in the second stage. All right, we're gonna do this very quickly, guys, because again, I'm trying to do this new commitment to tell you what you need to know and then walk away. Walk away. So, tolac, is there a risk for an extension that's unintended? Not again, not bandage scissors going up. But is there a risk of TOLAC rupture? And would you let this patient tolac. I think I put a little insta reel with one of our graduating seniors where we asked her, I asked her this question. Would you let a patient tolac who's had an extension and she hit it right on the head, she was like, well, wait a minute, isn't that all non contractile? Anyway, so, I mean, really, who cares? Well, yeah, that's true. Cause remember that low transverse hysterotomies are actually high cervical. Cause the lower uterine segment is anatomically a creation of the third stage laboring uterus. And so it's all Non contractile. The good news is there really is no conglomerate, no entire body of evidence as of right now, as of May of 2026, that just because there is an extension that that patient should not tolac, nor is there firm data that that increases the risk of TOLAC rupture. That's good news. Yeah. There's been plenty of studies that have looked at this, both national and international. There's been single center, multi center. And as of right now, there is no definitive proof. Guys, I'm gonna read you the excerpt here from this new publication, but there's no definitive clear evidence that that is a warning sign. That is good news. That's why it's not a contraindication. That's why we don't look at the op. Note to go, was there an extension? And the reason we don't get all worked up about it is because in general, I'll be very clear here, guys. In general, the data is just not there. That's going to increase the risk of some kind of harm with subsequent tolac. So unless once again, this is deliberate and you actually go into the contractile portion going upwards, in which case now it's a vertical extension. That's a different issue. That's like a classical, any kind of classical in the contractile portion, that's different, guys. But for a traditional lateral, medial, medial lateral extension or straight down inferior extension of the hysterectomy into the non contractile portion, that's not a contraindication for subsequent tolac. Overall, these studies do not permit firm conclusions about whether or to what extent prior unintended hysterotomy extension increases the risk of uterine rupture in subsequent pregnancies. So there it is. We just don't have the data. It doesn't seem to be a big deal. It doesn't seem to be an issue. And as of right now, that is not a traditional contraindication. By acog, smfm, the Royal College, SOGC or Nice. It's good to know what happened. But that's not gonna preclude her from undergoing a trial of labor at C Section. Podcast Family. We have reviewed a brand new publication that just came out at the end of April, start of May of 2026 in the green Journal. The title is Unintentional Extensions of the Cesarean Hysterotomy Incision. A Review and Proposed Classification System. Officially out on April 30, 2026. I think I may have said it came out on May 3rd. Sorry, three days off it was April 30th, 2026, and we're doing this in the first week of May of 2026. May get released, I don't know, a little bit after the first week, but definitely will be out in our podcast live in our channel in the first part of May of 2026. Once again, narrative review from the Green Journal ahead of print, because it's not out officially yet. About unintended Astronomy Extension Podcast family, as always, we're thankful for you. We're glad you're part of our podcast community. Michael, we did it. Let's be done here. Now that we've done all that, Mike, let's take it home.
