Welcome to the Augs Urogynecology webinar series. I'm Dr. Katherine Husk, Augs Education Committee member and the moderator for today's webinar. Today's webinar is titled Anal Sphincter Injury, Diagnosis and Implications for Future Pregnancies. Our speaker today is Dr. Leeshan Kiros. Dr. Kiros is a professor at the University of Oklahoma Health Sciences and is board certified in obstetrics and gynecology and urogynecology and pelvic reconstructive surgery. She completed a fellowship in urogynecology at Johns Hopkins. Dr. Kiros has national and international recognition and is best known for her work in the field of 3D ultrasound of the pelvic floor. She is one of the leading scholars in the nation on this topic. She teaches numerous lectures and workshops at national and international conferences and has published over 75 peer-reviewed manuscripts in addition to review articles and book chapters. Dr. Kiros holds positions of national and international prominence in the field of urogynecology. She serves as chair of the Radiologic Evaluation Committee for IUGA. She has previously served as assistant editor of the Urogynecology Journal and has served on the Augs and ACOG board of directors. Currently, she is a board member of the URPS subspecialty section of ABOG. She is an expert in robotic, laparoscopic and vaginal surgery and has a strong commitment to the medical education of students, residents and fellows. Dr. Kiros is currently the division director of urogynecology at OUHSC and serves as the OBGYN service chief for the Department of Obstetrics and Gynecology. Before we begin, I'd like to review some housekeeping items. The presentation has been prerecorded and any questions will be answered by Dr. Kiros via written responses on the Augs e-learning portal. Augs designates this live activity for a maximum of one AMA PRA category one credits. To claim your CME credit, you must log into the Augs e-learning portal and complete the evaluation following the completion of the webinar. The webinar is being recorded and live streamed. A recording of the webinar will be made available in the Augs e-learning portal. Please use the Q&A feature of the Zoom webinar to ask the speaker any questions and please use the chat feature if you have any technical issues. Augs staff will be monitoring the chat and can assist. Hello and thank you for the opportunity to speak with you all today. My name is Dr. Alicia Kiros from the University of Oklahoma. And today I'll be speaking on anal sphincter lacerations, injuries, diagnosis and implications for future pregnancies. I'd like to thank the Augs education committee for the invitation. These are my disclosures. So today we're gonna be discussing anal sphincter lacerations, including anatomy risks and clinical implications. We're gonna discuss the diagnosis of these injuries including ultrasound evaluation as well as an evidence-based counseling approach for future pregnancies. So in 2012, ACOG convened to form that revitalized obstetrics data definitions conference. And this enabled us to develop a clinical data definition to communicate nationwide. This is currently available to you all and it allows for us all to speak the same language. For our international colleagues, we also have this same shared terminology. This is the IUCAA ICS joint report terminology for female interrectal dysfunction. And fecal incontinence is defined as the complaint of involuntary loss of feces. Anal incontinence is the complaint of involuntary loss of feces and or flatus. So let's discuss some anatomical relationships. We'll start with the anal canal, which is about a two and a half to four centimeter long anal canal where the rectal ampulla is narrowed by the anal rectal ring. This is an actual muscular ring that is formed by the fusion of the puborectalis with the more inferior internal and external anal sphincters. So we'll discuss the role of the puborectalis, internal anal sphincter and external anal sphincter with more details. As a quick reminder, the inferior anal canal can be divided into the proximal and distal portions. And it's divided by an irregular line formed by the anal valves called the dentate line. So these areas differ in origins of arterial supply, nerve innervation and venous lymphatic drainage. So I'm going to briefly discuss the anatomy of the anal sphincter complex and how it relates to fecal incontinence. We'll start with the puborectalis muscle, which is the muscle that acts as a sling running behind the pubic symphysis around the anus and back. Contraction of this muscle decreases the anal rectal angle and prevents stool from passing from the rectum into the anus. I put this picture on the side for you all to see because it's a useful picture for you to visualize this relationship badgerly. We're also going to examine this relationship when we look at some axial images. The muscle can quickly contract in response to an increase in intra-abdominal pressure. And more importantly, it also relaxes during defecation, which allows for the anal rectal angle to straighten up. So the internal anal sphincter is the terminal thickened portion of the smooth thickened portion of the GI tract. So it is under autonomic control and really contributes 70 to 85 of the resting anal tone. It's responsible for continence of liquid stool and gas. And dysfunction of this muscle can contribute significantly to passive fecal incontinence. It is under the intervention of the superior rectal and hypogastric plexus. The external anal sphincter ends just distantly to the internal anal sphincter. And the external anal sphincter is really a striated muscle that provides most of the squeeze pressure that is important for maintaining anal continence. It is innervated by the pedendal nerve and damage to this sphincter is definitely associated with fecal incontinence. I would like to recommend for you an article that was recently published in the Gray Journal in 2024 by Dr. Delancey. And in this specific article, they discuss obstetric injury and levator ani injury. What I want to highlight from this specific study is the relationship that we just mentioned between the external anal sphincter and internal anal sphincter and the puborectalis all contributing to the anal rectal angle. I also want to point out that for purposes of imaging, you need to understand that all of the anal sphincter complex muscles that we need to visualize occur distal to the puborectalis muscle. So I get asked sometimes, how deep do we need to put the probe into the rectum? That's going to vary from patient to patient. Visualization of the puborectalis muscle should be one of your main landmarks and imaging all the muscle and distal to that muscle that will give you all the information that you need regarding the anal sphincter complex. So not to get too cheeky, but really childbirth is a way of life. We're gonna continue to do this. We have been doing it for thousands of years. Perineal trauma itself is common occurring in nine out of 10 women. Second degree perineal tears are twice as likely in permiparous births with an incidence of about 40%. The incidence of obstetric anal sphincter injury is about three to 4% in the United States. This incidence is gonna vary pending the area of the world in the literature that you're reading. The risk in the US and in all areas is higher in permiparous women compared to multiparous women. Obstetric anal sphincter injury is really a significant risk factor for the development of anal incontinence. And approximately 10% of women tend to develop symptoms within a year following birth. In fact, we are probably sub-estimating this impact. We learned from a cohort of approximately 1,000 women who were recruited in a prospective cohort study looking at pelvic floor outcomes five to 10 years after childbirth that 20% of women who had sustained an oasis complained of anal incontinence. So we may be sub-estimating, this is an underestimation likely of the number of patients affected by anal incontinence following oasis. Now, all grades matter as I tell my kids, right? So a study looking at 531 consecutive women who sustained oasis and then underwent repair noted that approximately 75% of these were permiparous women. These women were then followed and they had measurements of defecatory symptoms and bowel-related quality of life measurements. From the 531, approximately 42 and 41% had grades 3A and 3B. 216, pardon me, 42 and 50 of them had grade 3C and grade four. Compared to those with 3A and 3B, those with 3C or four tears were more likely to have more substantial anal incontinence and bowel dysfunction. The main outcome was to look at the tears compared, the major tears compared to the minor tears and what we learned from this study also was that involvement of the internal anal sphincter is a poor prognostic factor for outcome despite of the primary repair. So this also highlights the importance of recognition of this important anatomical muscle. So key aspects of the problem are that we know that repairing and caring for the perineal lacerations are part of our training as OBGYNs. It's part of our clinical expertise but with a decrease in the number of episiotomies being done and operative deliveries and a decreasing number of obstetric anal sphincter injuries to repair, then we also have obstetric providers needing to then supplement their OASIS repair training possibly by the use of simulation. So there are validated models developed to practice and teach OASIS repair skills such as the beef tongue. Before we go there, I'd like to spend a couple of slides looking at what we know about risk factors and recognition of them. So overall risk factors for OASIS include vaginal delivery, obstetric factors, obstetric and operative vaginal delivery, episiotomy, fetal microsomia, prolonged second stage and fetal occiput posterior position. I'll be enough, we'll review some obstetric factors including operative vaginal delivery, episiotomy, operative vaginal delivery, episiotomy and a history of perineal trauma. In looking at all factors, the risks for OASIS are broad and in this review of a meta-analysis including 43 studies in the literature including 22,000 women who have sustained an OASIS, the risk factors identified included epidural anesthesia, operative vaginal delivery and episiotomy. I'm highlighting those because those are the modifiable risk factors that we need to understand and remember and know about. More on operative vaginal delivery. So the risk of OASIS is in subsequent fecal incontinence increased with operative vaginal delivery both in vacuum-assisted and forceps. We have a large retrospective cohort study including singleton term patients within the Kaiser Permanente Northern California area and in this population, OASIS occurred in 24% of vacuum-assisted deliveries and compared to 4% of spontaneous deliveries. In addition, in a study of over 100,000 spontaneous vaginal deliveries, what we saw was that this included two tertiary care centers OASIS occurred in 8% of forceps-assisted deliveries, 3% of vacuum-assisted deliveries and approximately 1% of spontaneous vaginal deliveries. So again, the literature suggests forceps a greater risk than vacuum. Let's discuss episiotomy a little more. So the more common type of episiotomy performed in the U.S. has been the midline episiotomy which really starts about three millimeters on the midline of the posterior foreshad and extends downward zero degrees. In Europe, a medial lateral episiotomy is more frequently performed. This starts within three millimeters of the midline in the posterior foreshad and is directed laterally at an angle of at least about 60 degrees towards the ischial tuberosity. Episiotomy rates have decreased steadily since 2006. I just got my voice back, guys. It no longer is a common practice. So approximately in 2012, we saw approximately 12% of vaginal births including an episiotomy. Most of the literature implicates midline episiotomy. However, from what we know, a meta-analysis of over 700,000 pregnant women actually looked at and found that medial lateral episiotomy neither increased nor protected against perineal lacerations. So this study also looked at a six-fold decrease odd of developing OASIS when a medial lateral episiotomy was performed at the time of an operative vaginal delivery. Rarely, these can still extend into the anal sphincter. However, at this point, the teaching goal of this slide is if necessary, we recommend a medial lateral episiotomy in order to increase the risk of OASIS. So what do you know about a history of perineal trauma? So we know perineal trauma is more common in the first delivery. We just talked about that. And the risk is also increased in subsequent deliveries. Martin et al. looked at a retrospective study of 1,800 women and found that after adjusting for confounders, what they saw in a second birth increased threefold in women with a history of perineal trauma. So there's risk increased further with the severity of perineal trauma sustained in the first birth. So the average rate of OASIS was 6% with a range of anywhere from two to 13%. So the key aspect of this is gonna be in prevention. It is important to prevent this damage in the most women that we can in order to actually make a difference in decreasing the risk of anal incontinence. So what is next? We have a lot of different predictive factors out there contributing to relative risks and so on and so forth. But we would in the longterm love to put together a prediction model in order to be able to guide clinical thinking. This is currently still in the infancy stages. We don't have enough data on this topic and this is beyond the scope of the talk that I'm giving today. Some of the models that have been reported in have a low specificity, which can lead to a high false positive rate with potentially unnecessary interventions. So at this point, we need more research to create something that can be clinical useful in the prediction model in order to counsel women appropriately in the antenatal period. So it's important to be ready. And it's at this point, you all need to make sure you understand that repairing and caring for perineal laceration is definitely part of your job, and you may be called to help out at any one point, especially as a urogynecologist. You need to set yourself up for success in this kind of a setting. So whenever there is an implication or a difficult delivery or a large laceration, at this point we need to be emphasizing adequate exposure, adequate lights, adequate anesthesia, assistance with the need for help if we need it, along with a thorough examination of every vaginal delivery at the end of, especially at the end of a repair. So I mentioned that experience is an important point, and I want to just bring this up because I came across a study looking at a single-center quality improvement study looking at investigating post-repair complications, and really the three major causes that were identified were linked to inexperienced surgeons, inappropriate suture source, and inappropriate repair type. So in this same study, a targeted educational program was then implemented to fix all of this, and we were able to decrease the incidence of repair failures from 29 to about 12 percent, so about 50 percent reduction. I want to bring this up because this is a great opportunity for you to stay on top of what's new out there. This is hot and off the press. I would like to bring to your attention this newly published expert review by Dr. Schmidt and Dr. Fenner in Michigan, looking at the repair of oasis and fourth-degree lacerations from first to fourth-degree lacerations. This is a fantastic read. It includes a review of anatomy along with recommended suture choices and a checklist for repairs, including a description of the environment, preoperative preparation and instruments, all of your surgical materials, and the suggested postoperative care. I want you all to print this out as part of a checklist and make sure you bring it and provide it to your labor and delivery unit. It is important to bring awareness and to prepare to bring and to have these instruments in this setting and to optimize our chance of a successful repair the first time around. The reason being is that risk of wound complications is high. So this was—I want to highlight a prospective study of women who sustained obstetric lacerations during—after full-term delivery, and these women were seen at a urogynecology clinic within one week of delivery at 2, 6, and 12 weeks postpartum. This was—the visual analog scale for pain was administered at each visit. What we saw was that there were 615 women who sustained obstetric anal sphincter laceration, and the overall risk of wound complication was approximately 20%. So that is very high. Okay? Now, most of these were treated with 7 days of antibiotics, but it's important for you to know that 20% of the OASIS lacerations in this specific study were then involved in a subsequent wound infection. So when is the timeline to perform a surgical intervention after you've had a disruption? So this is a case series looking at early intervention in women reporting to a perineal clinic. This is more work done by Dr. Cristina Lewicki-Gaup, who has done a fantastic job in making sure that we have evidence-based literature on this topic. So this is a case series of women presenting to this subspecialty peripartum clinic. So these women underwent a secondary surgical repair. So the majority of women, 16 approximately, underwent a spontaneous vaginal delivery, and 13 suffered a third-degree repair. The median time for diagnosis to wound breakdown was approximately 19 days. At three months postoperatively, no women had a wound breakdown or recurrent fistulas. So the other point that I want to bring up is that antibiotics really do help decrease the risk of wound infections. So if there is a fourth-degree laceration going on, or a third-degree or fourth-degree laceration, you need to remember to give antibiotics. So antibiotics should be given before any OASIS repair. We have level one data for this. So this was a randomized controlled trial involving 147 women. All of these women were given a second-generation cephalosporin compared to placebo. Providers and patients were blinded, and the main outcome was wound complication at two weeks postpartum. The total wound complication rate was in less than the two components was because of the women who had sub-outcomes. So the preoperative antibiotics, as mentioned, should be administered. Overall wound complications were low, and at this point what we saw was that there was a reduction in the overall wound complications secondary to antibiotics. So we saw a difference between 24% to 8%. For postoperative care, patients should have close, frequent follow-up, including a thorough examination. Documentation is key. So it's important to inform the patient of the findings of your exam, okay? The Foley really should be left in place after this kind of repair because there's an increased risk of urinary retention. Pain control is important, and stool softeners and perineal care are also of utmost importance. Close follow-up is recommended in two weeks after this repair, and close monitoring following the healing of that incision. It's important for you to remember that women at high risk of pelvic floor disorders and complications for perineal trauma will then develop symptoms that fall outside of what you would typically expect. Postpartum presentation of OASIS. So have a low index of suspicion. So in women who are reporting with defecatory problems and had a recent repair, or patients who had a disruptive perineum, or patients who had an intact perineum who had a recent delivery, or showing any signs and symptoms of anal incontinence, these women should be evaluated, right? Your evaluation should include a detailed history as well as an examination. A digital rectal examination is going to be crucial. And whenever you are unsure about the integrity of what you're feeling, that is when it's important to then bring in imaging as part of your armamentarium of techniques that you have. Anal manometry and defecography are not really part of the standard workup, but may be used for more complex defecatory dysfunction symptoms. I want to point out the positioning of the patient for endoanal ultrasound. So the patient is placed in the dorsal ethiotomy position. There's no special preparation that needs to happen. It can be done also in the left lateral position, and after which you have the placement of the 3D endoanal probe placed in the anal canal. What I'm highlighting in this video coming up is an example of the visualization of the puborectalis, which is the main one of the muscles that I highlighted earlier as being a landmark for you to locate yourselves. So we visualize, we go in as proximal as the puborectalis, as this is pointing out here. And anything distal to the puborectalis is going to be basically where you are going to need to focus on the external anal sphincter and internal anal sphincter complex, okay? So different areas to evaluate, up higher and proximally, this is something that has been previously published by Dr. Salton et al. in the UK. At approximately level one, which is the highest and proximal one, you're going to see this puborectalis muscle. At approximately level two, you're going to see a combination of both. And the external anal sphincter, since it is a skeletal muscle, it is going to form a hyperechoic ring around the anal canal over here. The internal anal sphincter, since it is a smooth muscle, it is going to appear as a hypoechoic ring surrounding the anal canal. This is a picture that I showed you earlier, and I showed you the movement between the proximal and distal portions of the anal canal on 3D ultrasound. And I also want to point out that in this specific picture, we have the transducer in the rectum, and we have an intact anal sphincter, okay? Let's visualize that again. So we have a hypoechoic ring around the anal sphincter, and this appears to be an intact internal anal sphincter, after which we see an external anal sphincter defect. Just for you to train your eyes, I'm going to backtrack on that again. So first, you see the intact internal anal sphincter, smooth muscle, the external anal sphincter, hypoechoic, skeletal muscle, and there's a defect. It's important for you to go back and forth on these images. Sometimes you may have attenuation or thinning of the external anal sphincter in the anterior portion, or you may have the effect of the actual transducer squeezing that muscle, making it a little bit thinner. So it's important for you to maintain your probe in a neutral position. And I would recommend reviewing, and hence the reason for 3D ultrasound, recommend reviewing it at the different levels in order for you to confirm the presence of a defect. So let's talk about counseling. And in counseling women as to the risk of recurrence of OASIS, we know we have predictors such as operative deliveries, previous fourth-degree tears, and we also know that the impact of recurrent OASIS on fecal incontinence is significant, and up to 26% with a prior fourth-degree laceration. So with a prior major laceration, we need to make sure that our patients understand that they have an increased risk of a repeat major laceration, and likely will continue to have these anal sphincter problems. We also have recent large meta-analysis, including 103 studies involving 16,000 patients. Of all the women delivered vaginally in this group, OASIS was diagnosed on ultrasound in 26% and 20% approximately experienced anal incontinence, so a slight over-diagnosis based on imaging alone. So following approximately 2 out of 5 women who underwent a primary repair of OASIS will become symptomatic, and 1 out of 10 will develop fecal incontinence during the first year postpartum. In the next two slides, I want to give full credit to Dr. Cristina Lewicki-Gaup. She's done a magnificent job in putting out this literature. I want to also thank her for the information, because I'm using some of her information on these slides. She gave a fantastic presentation on fecal incontinence and obstetric laceration, and I took notes. One of the main things I want to point out from this slide that she pointed out was that in counseling, whenever you have women with FI symptoms, so if they have no fecal incontinence, the next vaginal delivery will likely concur a low risk of fecal incontinence. If they have transient fecal incontinence, that is something that initially was there but then eventually got better, so there is a risk of temporary FI with the next vaginal delivery, but there's also a risk of persistent FI with the next vaginal delivery. That needs to be clearly communicated with the patient. If a patient had a major third or fourth TIGV laceration and the presence of fecal incontinence, likely a next vaginal delivery will contribute to further functional deterioration. So we talk about anal sphincter defects, and we mostly talk about anal incontinence, but really one of the other things that really takes a big hit, along with all other quality of life measures, is the ongoing sexual dysfunction for these young patients. So this is an ongoing problem, and at this point, we know that about 90% of women, after about three months post-delivery, tend to return to sexual activity, but patients who have sustained an oasis actually delay that further, okay? About 94% have delayed it by about a year, however, 64% continue to report sexual dysfunction in the first year. Another aspect I want to add to this is a study done by O'Shea et al. looking at and reporting that even three years after sustaining oasis, up to half of women and male partners meet the criteria for sexual dysfunction. So really, this is a prolonged and really terrible amount of suffering that our patients undergo after these conditions. So in conclusion, the prevention of perineal trauma and the sequela include perineal pain, dyspareunia, pelvic organ prolapse, and these are important outcomes for women. Periodic trauma is not uncommon. It is common when you look around you. We need to disseminate the literature we have on this topic. We need to have a better appreciation of the modifiable risk factors that we understand from the literature, and we need to make sure that we are informing clinicians and our patients as to the risk of subsequent deliveries. Quality diagnosis is key. Surgical skill sets are essential, and this is where simulation and asking for help from a skilled set of hands is important. I want to put a shout out for the need for more perineal clinics. These are important centers for providers to refer patients to, and in all honesty, patients who have undergone a perineal laceration who have a perineal clinic nearby should be offered the opportunity to visit and follow up in these clinics. It's important to make sure that we start looking for these symptoms early on and that we try to minimize the level of suffering that these patients incur. Also, going along with earlier diagnosis is earlier intervention, including behavioral modifications that could be already improving their quality of life. You all know about them. I didn't include a slide about them. Behavioral modifications such as pelvic floor strengthening, you already know that fiber is essential for that as well. So, understanding their stool consistency, their symptoms, understanding their bowel habits specifically is important, and it needs to be done in a setting of clinicians that understand this condition. So preventative and a recovery approach in this population is where it's at. I mean, it's where we need to focus on at this point. I want to make sure that after this talk, you print off the checklist that I highlighted earlier on. I list a few different articles at the end of the references. I didn't include absolutely all of them, but definitely the key ones. I want you to make sure to read a couple of the review articles that I highlighted earlier in my talk. That will bring you up to speed as to where we stand and will keep you up to date. Please also help disseminate this information to your academic generalist colleagues. They are seeing the majority of these patients firsthand, and we need to make sure that our primary care and family care providers, family physicians specifically, family med, that they also are aware of the earlier signs and early recognition of this problem. Thank you, and I look forward to hearing about your questions as they will be emailed to me.

Urogynecology

Anal sphincter injuries

Childbirth

3D pelvic floor ultrasound

Obstetric anal sphincter injuries

Episiotomy

Diagnosis and repair

Pelvic health