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Most individuals associate anal pain with hemorrhoids. However, there are many conditions that can cause anal pain and bleeding, and physical examination helps to differentiate between these diagnoses: anal fissures, hemorrhoids, or infections. An anal fissure is a superficial tear in the anoderm. Fissures are diagnosed clinically by history and physical exam with careful spreading of the anus and direct visualization of a break in the mucosa and exposed sphincter fibers. Increased tone of the internal anal sphincter can inhibit fissure healing by decreasing blood flow to the mucosa. Conservative management includes stool softeners and warm sitz baths to avoid traumatizing the fissure with hard stools and relaxing the sphincters with warm water. Topical nitrates or calcium channel blockers applied at the anal verge dilate and relax the internal sphincter muscle to promote healing. Alternatively, injection of Onobotulinumtoxin A into the fissure and intersphincteric groove paralyzes sphincter muscle, decreasing muscle spasm and supporting healing of the fissure. For individuals who fail these conservative therapies, lateral internal sphincterotomy is considered. This procedure involves dividing the internal sphincter muscles but carries a small risk of fecal incontinence. We present the case of young adult male with a history of a chronic anal fissure, who failed medical management. Posterior anal fissure was appreciated on exam and treated with Onobotulinumtoxin A injection for relaxation of anal sphincter.
An anal fissure is a shallow superficial tear in the anoderm distal to the dentate line.1, 3 Fissures form secondary to trauma of the anal canal related to constipation, diarrhea, or injury.3 Fissures cause anal pain, spasms, and bleeding and are predominately (approximately 75%) located in the posterior midline.1 Fissures may be acute or chronic, defined as lasting greater than 6 weeks.1 The incidence of fissures is most common in young or middle-aged patients and equally likely between men and women.1 In the United States, over 250,000 new cases are diagnosed each year.3
Male in his 20s with a history of chronic posterior anal fissure with anal pain and bleeding. This patient was previously managed with conservative medical management, including topical calcium channel blocker and pelvic floor physical therapy for the prior two years. His bowel symptoms waxed and waned, initially improving with lifestyle modification, relaxation techniques, and topical creams. He presented with an acute exacerbation of anal fissure with increased pain and bleeding.
Anal fissures are visible separations of continuity of the anoderm evident on rectal exam. Chronic fissures may also exhibit hypertrophied anal papilla, an associated skin tag or exposure of the internal anal sphincter at the base of fissure.4 Increased sphincter tone may limit exam in the outpatient setting.1
The course of an anal fissure can create a positive feedback loop, exacerbating symptoms and leading to the chronicity of the lesion.2 For example, pain will increase anal sphincter tone which in term limits blood flow to the anal fissure. This limited blood flow thereby limits healing of the lesion and exacerbates pain and chronicity of the fissure.
Acute anal fissures can likely be managed with conservative, non-operative therapy.1,4 This course includes utilization of stool softeners, adequate hydration, and dietary fiber.3 These measures are curative for half of patients with acute anal fissures. Additional therapies for chronic fissures include sitz bathes, topic nitrates, or calcium channel blockers, which resolve half of chronic fissures.1,2,3 Levator relaxation techniques and pelvic floor physical therapy are also recommended when there is high pelvic floor tone.4 The goals of these therapies are to target the underlying pathology leading to fissure formation such as constipation, straining, or diarrhea and allow for healing via sphincter relaxation, which increases blood flow to the fissure.
Onobotulinumtoxin A injection is an option for patients who have failed conservative therapies.3 The toxin is reconstituted in a small volume of sterile saline. We use 1 cc of normal saline to reconstitute 100 units. Onobotulinumtoxin A is injected into the fissure and internal sphincter.4 This procedure can be performed in the office or in the operating room with sedation for patients experiencing severe anal pain. The concentration, dosage of injection, and specific location of injections are surgeon dependent. There is a paucity of high quality studies that describe technique and support effectiveness. The pathophysiology is that Onobotulinumtoxin A causes temporary paralysis of the internal anal sphincter, reduces in anal sphincter tone, and promotes healing by increasing blood flow to fissure.1 Complications of this procedure are low, but the following has been reported: fecal urgency and incontinence, hematoma, proctitis, and injection site infection.
Finally, operative management of refractory chronic anal fissures include lateral internal sphincterotomy (LIS), the radial exposure and division of the internal sphincter muscle, and anal dilation.2,4 While LIS has a greater than 90% success of resolving anal fissures, it has an increased incidence of incontinence relative to the procedures outlined above.1,2,3
Anal fissures found in atypical locations, such as the lateral, are worthy of special considerations including Crohn's disease.3,5 Patients with Crohn's disease should have optimized medical management of inflammation prior to considering procedural intervention of anorectal lesions.1,3 Patients who have anal sex may develop anal fissures secondary to sexually transmitted infections including chlamydia, gonorrhea, or syphilis.6 Patients with HIV are at increased risk for AIDS-related ulcers or ulcerating herpes simplex virus, which may be indistinguishable from an anal fissure.1,3 Non-healing lesions may also suggest a neoplastic process, which must be ruled out.
The patient was a young adult male with a history of chronic anal fissure with increased symptoms of pain and bleeding despite a prolonged course of conservative medical management. Patient received botulism toxin injection to reduce anal sphincter tone and promote healing of fissure. The Onobotulinumtoxin A was reconstituted by injecting 1 cc of injectable saline into the vial of 100 units. The 100 units was injected on either side of the fissure and in the intersphincteric groove on both the right and left sides for sphincter relaxation.
Patient positioning in either lithotomy or prone position provides excellent exposure to anorectal pathology, and in this video, we opted for lithotomy positioning with Yellofin stirrups. A pudendal block was performed for postoperative pain control by identifying the ischial tuberosities on the right and left side and injecting 0.25% bupivacaine medially to infiltrate the neurologic bundle. Typically, fissures are not sutured closed, but if the mucosal edges are retracted and scarred, then creating mucosal flaps and loosely approximating the edge can facilitate healing.
- Onobotulinumtoxin A reconstituted in sterile saline. Dilution of 100 units in 1 cc of saline was used in this case.
- Anoscopes in different sizes to facilitate visualization into the anal canal.
Nothing to disclose.
The patient referred to in this video article has given their informed consent to be filmed and is aware that information and images will be published online.
- Beaty JS, Shashidharan M. Anal fissure. Clin Colon Rectal Surg. 2016 Mar;29(1):30-7. doi:10.1055/s-0035-1570390.
- Ebinger SM, Hardt J, Warschkow R, et al. Operative and medical treatment of chronic anal fissures - a review and network meta-analysis of randomized controlled trials. J Gastroenterol. 2017 Jun;52(6):663-676. doi:10.1007/s00535-017-1335-0.
- Jahnny B, Ashurst JV. Anal fissures. [Updated 2021 Nov 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526063/.
- van Reijn-Baggen DA, Elzevier HW, Putter H, Pelger RCM, Han-Geurts IJM. Pelvic floor physical therapy in patients with chronic anal fissure: a randomized controlled trial. Tech Coloproctol. 2022 Jul;26(7):571-582. doi:10.1007/s10151-022-02618-9.
- Stewart DB, Gaertner W, Glasgow S, Migaly J, Feingold D, Steele SR. Clinical practice guideline for the management of anal fissures. Dis Colon Rectum. 2017 Jan;60(1):7-14. doi:10.1097/DCR.0000000000000735.
- Assi R, Hashim PW, Reddy VB, Einarsdottir H, Longo WE. Sexually transmitted infections of the anus and rectum. World J Gastroenterol. 2014 Nov 7;20(41):15262-8. doi:10.3748/wjg.v20.i41.15262.
Cite this article
Shearer J, Gurland B. Anal examination under anesthesia and Botox injection for chronic anal fissures. J Med Insight. 2023;2023(371). doi:10.24296/jomi/371.
Table of Contents
- Mucosal Approximation
Hi, I'm Dr. Brooke Gurland. I am a colorectal surgeon and I work at the Stanford Pelvic Health Center. I do a lot of anorectal work, and with anorectal, you frequently see anal pain, chronic anal fissures, hemorrhoids, and whatnot. And almost everybody comes in saying that they have a hemorrhoid, but actually there's many other diagnoses that it could be. In this specific case, I am taking care of a young gentleman in his twenties who has had chronic anal fissures and he's had several different treatments in the past. For chronic anal fissures, we usually talk about making sure that the bowels are soft, doing things like sitz baths, so that relax the muscle and help the fissure to heal as well as either a calcium channel blocker to apply to the anal area or a nitroglycerin; both of those help relax smooth muscle and allow a fissure to heal. Now he has done all of those things and yet he continues to have fissures. And at some point he did them, and it improved a little bit, and actually his fissure's been going on for several years. So he's done that. He actually has even done some pelvic floor physical therapy and that is to learn coordination as well as relaxation. So he is really quite adept at this point in knowing what his bowel movements are like and doing a lot of behavioral modification. So when he came back in to see me after some time with persistent pain, he actually knew exactly what he had, which was the fissures, and had already initiated the creams, which he had done for a certain time period. And then when I took a look in the office, I could see that he had anal fissures. And I like the term chronic anal fissures in that it has been going on for some time. As well as I could see the white fibers of the sphincter muscle - it's showing me that there's some chronicity. So my plan for him - he has two actual or, you know, three options, in that he could stay as he is. Another option would be to inject Botox, and that's injected into the actual fissures into the internal sphincter to help with relaxation and healing. And then the kind of gold standard, or the go-to at the end would be something called internal sphincterotomy. And I certainly could have offered him that, and that's where I divide a little of the internal sphincter muscle. But we opted for Botox. And so - and again, he wanted to avoid any kind of a sphincter cutting, and I'm quite agreeable. So I usually give 100 units of Botox - that could be quite high. Some people who frequently do this may give less dose, but I have to open the vial anyway and I haven't found in this group that I'm causing any incontinence. I may give a lower dose if I think they have lower sphincter pressures or I'm concerned. But in most of my patients who I'm offering, they really can tolerate the 100 units. And you'll see when I do the procedure exactly what that looks like. Also because I could see that the mucosa was sort of scarred down and they were far apart, the edges, I sometimes, and not always, like to lift up the mucosal edges and just approximate them a little bit. I'm not trying to close anything. I can't close the fissure or force it to heal, so to speak. But I was just trying to approximate the edges to facilitate healing and by kind of roughing up surfaces bring in new cellular growth and all of those good wound-healing things to promote healing. So when I go to do the key steps in the procedure, it's really about drawing up the Botox, and I'll show you how I specifically do it. And there's really many ways to do it. So drawing up the Botox, positioning the patient so that you have a good visualization of the area. I could do this in lithotomy or prone. I did his in lithotomy, and the anesthesiologist loves me because of that because he can protect his airway. And sometimes I will give a block. In this case, we did. We did a pudendal block upfront just for some numbing. And after that we go ahead and do the injection into the sphincters. In this specific video, I did a little bit of anatomy. It shows you some things in case there's any students or anybody who aren't as familiar with the anal canal. And then you can clearly visualize the fissure. Interesting, he had both an anterior and a posterior fissure. Most commonly your fissures will be in the posterior location, but in some anterior. And lateral fissures are less common but can see in certain disease states, whatnot. All right, let's take a look.
Okay, so this is 100 of Botox. All right? And this is what it looks like. Okay, and it looks like it's empty. And so there's a little bit of the Botox right on the bottom there. That's what that is. And essentially I'm going to dilute it with some normal saline or mix those two together. And I choose the volume. I'm gonna use the full 100. Nobody really knows what the right answer is, how much Botox to give, but he's had chronic anal fissures, and I'm gonna give the full 100. All right, so I'm going to do this. I'm just gonna draw this up into my 1-cc syringe that I will be giving. And at the same time, he's being prepped and draped, and I'm just giving that, and what that does, it's just gonna... This really concentrated Botox is now being reconstituted. And I don't worry as much about the volume because I plan on just giving the 100 units. Okay. When the volume's small, sometimes it's hard for it to come out. I have to be underneath the - there we go. All right, so I'm just drawing up the full 100, and I'm gonna use that. Okay? Good. Then we can go ahead to the next step.
Okay, so just some basic anatomy. He is in the lithotomy position. So genitals are up here, and his legs are up. And right here you can see, I'm gonna call this like a little anal skin tag, right? It's hard to say what's an external hemorrhoid versus skin tag. This has kind of like a floppy sort of appearance. And here you see some prominent internal hemorrhoids. And then you look in two positions. I'm now looking here in this anterior location he's got a little bit of a fissure and he also has one in this posterior location. So he has two areas of fissures, and my plan is to give him some Botox that I will give in the fissures and also in all four quadrants actually. And in the intersphincteric groove. So next I'm gonna do a digital exam. So I'm gonna take a little bit of lube. Thank you very much. All right. And he's already been anesthetized. We gave him a pudendal block by injecting on either location. And he is under a heavy sedation. Gonna feel here, doing a digital exam. Let me take an anoscope, please. I'm gonna take a look on the inside. I'm gonna take a smaller one to start with and then maybe you can hand me the one that's a little bit bigger. Okay? Yes. And then we can adjust some light. Do this and maybe I should make smaller moves. Can you take that for me? Thank you. And can you give us some light in here? And then I'll take a Raytec. And I want you to just position your hand down, or maybe you hold the anoscope up like this. And here, this is the internal sphincter muscle that is exposed, and you can see kind of has a white appearance, and this has minimized, like it's not really healing. It's not gonna come together anymore. This has been going on for a long time. And me just kind of manipulating and roughing up the tissue a little bit can help. And then I'm gonna look over here. Actually I'm gonna change my position this way so you can get a view here. And then just from an anatomy perspective, you can see here's like a hypertrophied little bit of a papilla here. And dentate line is somewhere over here. And then when I'm feeling for the intersphincteric groove, that is the groove between the external sphincter and internal sphincter. And you get a sense, here's the internal sphincter, and my finger is in the groove. And this is just to give you a sense of anatomy. Okay, and then hold this down for a second, and let's look here, get a really good exam on him. This also is an area where he hasn't healed, and he's got this little area here like it kind of opens and closes, it looks like to me. Let's see. No, that looks okay. Like, there's almost like a little dot here in this location. Okay.
Let's start. We'll take the Botox next. I'm gonna start with the Botox on either side. So hold this up for me, please. I'll take the Botox. So this is the 100 units, and I'm gonna give it on either side. .Okay, I'm gonna give a little bit here. And a little bit here. All right. I'm gonna give now to this other fissure. Let's give here and here. Okay, and then I'm gonna give in both of these quadrants here - I'm giving into the intersphincteric groove. So my finger is in the groove, I'm pushing the internal sphincter up, and I'm injecting a little bit on this side. And then I'm gonna do the same thing on that side. Actually, what you wanna do is you wanna kind of come over to my side here. I don't want you to hurt your hand. Okay, we'll do this. Okay, nice.
All right, so the Botox is given, and in many cases that would be enough, but because this is so chronic, I wanna just clean the edges up and bring the tissue a little bit together. Even though you would never really close a fissure. Can I have the Bovie, please? You would never really close, but this has been going on for so long, but just kind of approximating might help just a teeny tiny bit. Just to get some clean tissue on either side. And then I would say the same thing over here in this anterior location. Again, very chronic. I just want to see if I can't stimulate some growth. All right. Okay, great. Now I'll take that Bovie for a second. And I'm just gonna... Okay, can I have a DeBakey? And actually, the lighted anus scopes are a little bit better for this and they're a little bit bigger. Can I have those, please? Okay. I've got to see these lighted ones. Okay. Hook up the light. And I just wanna stimulate a little bit of... Tissue growth. And I'm just gonna approximate. I wanna see that the edges come together. So again, I don't really normally close a little fissure here but this has been going on for so long, just gonna take a single Chromic and just approximate it to promote healing more than anything else. And I lifted it off the edges and stimulate some tissue growth. I'm gonna take a either a 2-0 or a 3-0 Chromic, if that's okay. Something... Yep. So sort of got rid of that little bit of that white appearance. I just wanna stimulate tissue growth. I'm not coning anything else, I'm not dealing with this tag. I never do that as part of an initial fissure healing, like even if he complained and said that that really bothered him, I wouldn't, it would just cause more pain. All right, and what I'm doing with the sutures, I'm just trying to promote bringing the tissue a little bit together 'cause it's physically apart. And then... Lifting the mucosa off. Yep. Okay. All right. I'll do that. Okay, and I'm just... And I'm not closing the whole thing in any way, shape or form, just approximating this mucosa. Okay, and then we'll do the same thing. We'll take a look on the other side. It's just to bring them a little bit closer together. Okay. Okay. and now we'll switch around. I'm gonna give this back to you. Great. And we'll go down to here. Okay, and we'll take a look at this. This one's a little bit smaller. Can I have a probe, please? Just wanna make sure, like one of those lacrimal duct probes. Can I have a smaller one? I just wanna see. That doesn't - there's no little fistula or anything. See how he's got this like, little kind of mucosal bridge here? Now it could be... Let's see. Like maybe it was a larger one, and this is the only thing that's left. So I'm not gonna do much with this one. This is small. It doesn't look as chronic as the other, but I am stimulating growth with that. Okay. And then what I would do next is just some irrigation. You can take this and unhook that.
We'll get rid of the light please. And we'll do a little bit of irrigation. And then we gave him - how much local did he get? Twenty? Okay. So let's give him a little bit more local. And why don't you go ahead and you can give him a block again in the two areas so he can tolerate - we're giving a quarter percent Marcaine, and he can tolerate a little bit more. Clean this up a little bit. Yes. Take this suction. Now this all looks okay. And we'll give him a little bit more local. Oh, there we go. Yep. Okay, great. Okay. And then a little bit more local. And you can kind of demonstrate what the technique - you already gave some upfront, but we could show everybody how you find that. Go ahead with your technique. Yep. Go medial. Nice. Aspirate. All right. And then give a little bit and direct it towards the other areas. Okay. And then we'll give another 10 on the other side, post-op. Okay. Okay, perfect. And it's a wrap. We're just gonna clean him off and we're done. Thank you.
That procedure possibly went a little bit slower than I normally do, and that's because we were videoing and doing a little bit of education around the anal area. I did, not just a Botox, but also lifted up a little bit of those mucosal edges and approximated them. I did that only in the posterior location, not in the anterior. So it's not really always part of my normal routine. Now as far as post-op goes, he is encouraged to go back and do the sitz baths. I tell him to keep his bowel soft. I talk about using ibuprofen and Tylenol for pain control. I do give a very short course of narcotic, just so they have it on hand, but I sort of, I encourage them to avoid it because it can be constipating. If they've used the creams before and don't have any issue with any of the either nifedipine calcium channel blocker, or nitroglycerin if they have them at home, I have no issues with them using it. And then I let everybody know that you're gonna have bleeding, you know, that is normal, and you will have pain because me stimulating that fissure and manipulating it can be painful. So it takes a minimum, I would say, of about six to eight weeks for healing and could be longer. And if he doesn't improve with the Botox, and I'm hopeful that he will, but if he does not, then I will talk to him about a lateral internal sphincterotomy. Thank you.