Progress in the understanding and treatment of chronic anal fissure

Oscillating calcium signals in smooth muscle cells underlie the persistent basal tone of internal anal sphincter

A persistent basal tone in the internal anal sphincter (IAS) is essential for keeping the anal canal closed and fecal continence; its inhibition via the rectoanal inhibitory reflex (RAIR) is required for successful defecation. However, cellular signals underlying the IAS basal tone remain enigmatic. Here we report the origin and molecular mechanisms of calcium signals that control the IAS basal tone, using a combination approach including a novel IAS slice preparation that retains cell arrangement and architecture as in vivo, 2-photon imaging, and cell-specific gene-modified mice. We found that IAS smooth muscle cells generate two forms of contractions (i.e., phasic and sustained contraction) and Ca2+ signals (i.e., synchronized Ca2+ oscillations [SCaOs] and asynchronized Ca2+ oscillations [ACaOs]) that last for hours. RyRs, TMEM16A, L-type Ca2+ channels, and gap junctions are required for SCaOs, which account for phasic contraction and 75% of sustained contraction. Nevertheless, only RyRs are required for ACaOs, which contribute 25% of sustained contraction. Nitric oxide, the primary neurotransmitter mediating the RAIR, blocks both types of Ca2+ signals, leading to IAS's full relaxation. Our results show that the oscillating nature of Ca2+ signals generates and maintains the basal tone without causing cytotoxicity to IAS. Our study provides insight into fecal continence and normal defecation.

Management options for chronic anal fissure: a systematic review of randomised controlled trials

INTRODUCTION

Anal fissure is the most common cause of severe anorectal pain in adults, contributing significantly to coloproctology workloads. There are a wide variety of management options available, including topical nitrites, calcium channel blockers, botulinum toxin injection and sphincterotomy. The aim of this study was to review current options for the treatment of chronic anal fissure.

METHODS

A comprehensive search identifying randomized controlled trials comparing treatment options for anal fissure published between January 2000 and February 2020 was performed. The primary outcome assessed was healing at 8 weeks post commencing treatment. Secondary outcomes included recurrence, intolerance of treatment and complications.

RESULTS

A total of 2822 studies were identified. After removal of duplicates and non-relevant studies, we identified nine randomized controlled trials which met pre-defined criteria. There was a total of 775 patients. At 8 weeks, healing rates were 95.13% in those treated with sphincterotomy, 66.7% in the botulinum toxin group, 63.8% in the nitrate group, 52.3% for topical diltiazem and 50% for topical minoxidil. Recurrence was highest amongst those treated with botulinum toxin injection (41.7%) and lowest for sphincterotomy (6.9%). Although the absolute number is low, there was a risk of permanent incontinence with sphincterotomy.

CONCLUSION

This review of the randomized control data demonstrates that healing was significantly higher amongst those treated with sphincterotomy versus more conservative modalities. Topical nitrites had similar outcomes to botulinum toxin injection but were poorly tolerated in comparison to other treatments. The benefit of sphincterotomy was at a cost of increased complications, notably permanent incontinence.

Safety and efficacy of the treatment of chronic anal fissure by lateral internal sphincterotomy: A retrospective cohort study

Background

An anal fissure is one of the most common anorectal diseases resulting from a longitudinal tear in anoderm under the dentate line. It causes severe pain during defecation, and the resulting emotional stress leads to a reduction in the overall quality of life of a person. There are several medical and surgical treatment procedures that are employed to treat anal fissures. In the present retrospective study, we aimed to evaluate the safety and efficacy of lateral internal sphincterotomy (LIS) surgical procedure for the treatment of chronic anal fissure. Additionally, we also analyzed the complications arising after the surgery and the factors affecting the complications.

Methods

The present study is a retrospective study that included 691 patients treated for chronic anal fissure in a private sector setting, by a single Saudi female surgeon, starting from April 2004 to April 2020.

Results

Out of the 691 patients included in the study, all the patients were female, with an average age of 45.77 years (ranging from 17 to 82 years). Major complaints of the patients were as follows: pain, bleeding, constipation, pruritus, perianal discharge. Recurrence was reported in 2 patients (0.3%) while, 3 patients (0.4%) developed gas incontinence.The complaints of all patients with gas incontinence regressed over a period of time.

Conclusion

This study reports that lateral internal sphincterotomy (LIS) is a safe surgical treatment for chronic anal fissure, leading to a reduction in recurrence, incontinence rate and substantially improves symptoms, especially pain.

A novel method of anal fissure laser surgery: a pilot study

Anal fissure is a common painful problem, affecting all age groups. Its pathophysiology is based on high sphincter pressures and reduced blood supplying and treatments which means that it generally reduces anal pressures and increases anodermal blood flow. Since each of the anal fissure's routine therapies has some limitations such as definite risk of permanent fecal incontinence and high recurrence rate, we tried to find a more effective and less invasive procedure. In this pilot study which was implemented on 25 male and female patients aged 20-75 years, diagnosed clinically with chronic anal fissure, the Carbon Dioxide Laser Fractional was used to treat patients. In order to first remove fibrotic and granulation tissues, the base and the edges of the fissure were laser beamed. Eight spots were made on the sphincter by the laser on its continuous mode; somehow, they were passed through the full thickness of sphincter without interrupting its continuance. Afterwards, the area around the fissure ulcer was irradiated by deep fractional mode of the laser to stimulate the submucosa to regenerate and rejuvenate. After going through this procedure, patients were followed up within 6 months to 1 year. Pain, bleeding, and constipation were significantly improved. None of the patients had recurrence after a 1-year follow-up, and none of them had fecal incontinence and/or inability to control the passage of gas too. This study revealed that this new laser-based surgery is a simple, safe, and effective procedure to treat the anal fissure that can be performed with local anesthesia in an outpatient clinic with minimal postoperative morbidity.

Isosorbide dinitrate ointment vs botulinum toxin A (Dysport) as the primary treatment for chronic anal fissure: a randomized multicentre study

AIM

Nitric oxide donors, such as isosorbide dinitrate ointment (ISDN), are considered as first-choice agents in the treatment of chronic anal fissure. Injection with botulinum toxin A in the internal anal sphincter is often used as a second-line therapy, although it may give better results and fewer side effects than nitric oxide donors. The aim of this randomized clinical trial was to investigate whether botulinum toxin A (Dysport) is more effective than ISDN in the primary treatment of chronic anal fissure.

METHOD

From April 2005 until October 2009, 60 patients (32 men) with a median age of 42 (25-82) years were randomized to receive either ISDN 10 mg/ml (1%) (n = 33) or injection with 60 units of Dysport (n = 27). The primary end-point was the percentage of complete fissure healing after 8 weeks.

RESULTS

After a median of 9 weeks complete fissure healing was noted in 18 of 27 patients in the Dysport group and in 11 of 33 patients in the ISDN group (P = 0.010). Absolute improvement of pain scores after 9 weeks was similar in both groups (P = 0.733). Patients treated with Dysport had fewer side effects than patients treated with ISDN (P = 0.028). Of the patients with a healed fissure, 28% of the Dysport group and 50% of the ISDN group had a recurrence within 1 year (P = 0.286; hazard ratio 2.08; 95% CI = 0.54-7.97).

CONCLUSION

Dysport is more effective than ISDN ointment and has fewer side effects in the primary treatment of chronic anal fissure. The recurrence rate within 1 year in both treatment groups is high.

Comparison of topical nifedipine with oral nifedipine for treatment of anal fissure: a randomized controlled trial

Background:

Medical sphincterotomy has gained popularity as a treatment for anal fissure. Calcium channel blockers in topical forms could also be appropriate with low adverse effects.

Objectives:

This was a prospective randomized controlled trial to compare topical and oral nifedipine in the treatment of chronic anal fissure.

Patients and Methods:

A prospective randomized controlled trial was conducted at two centers of Shahed University. One hundred and thirty patients with chronic anal fissure aged 18 to 60 years managed in our clinics were included in this study. The patients were randomly divided into two groups. Sixty-five patients received topical nifedipine (TN) and the same number received oral nifedipine (ON).

Results:

Ulcer healing occurred in 43 (73.33%) of topical nifedipine group compared to 29 (49.5%) patients in oral nifedipine, which was significantly different (P < 0.05). Side effects such as headache and flushing in oral nifedipine group were more prevalent than topical nifedipine, which was statistically different. Recurrence rates were the same after six months of follow-up.

Conclusions:

Although oral nifedipine can reduce symptom and signs of anal fissure, topical nifedipine has a superior role for anal fissure treatment with higher healing rate and lower side effects.

Subcutaneous internal lateral sphincterotomy (SILS) versus nitroglycerine ointment in anal fissure: a prospective study

AIM

To compare the results of subcutaneous internal lateral sphincterotomy under local anesthesia and nitroglycerin ointment treatments in acute and chronic anal fissures.

METHODS

This was a comparative, prospective study of 340 patients of acute and chronic anal fissure. The patients voluntarily opted either for the surgical procedure under local anesthesia, or the nitroglycerin treatment. All the patients were followed with regular checkups and complaints were documented.

RESULTS

Except for 1.75% patients having bleeding/hematoma formation, and with a dropout of 2.60% patients, no failure, recurrence or long term complications like incontinence, were observed in patients who underwent subcutaneous internal lateral sphincterotomy after a mean follow up of 28 months. With surgical treatment pain, bleeding per rectum and constipation showed significant improvement as compared to nitroglycerin treatment. Fissure healing was 100% in surgical group as compared to 56.90% in medical group (P=0.000, odds ratio=344.6). Nitroglycerin was equally effective in acute and chronic fissures (P=0.096).

CONCLUSION

Subcutaneous internal lateral sphincterotomy under local anesthesia is more curative, easy and safe, in the hands of a beginner as well as an experienced surgeon, with highest patient satisfaction, and should be considered as the first line of therapy in both chronic and resistant/recurrent acute anal fissures.

Idiopathic hypertensive anal canal: a place of internal sphincterotomy

BACKGROUND

Hypertensive anal canal is frequently known to be associated with the presence of anal fissure. Based on clinical experience, we hypothesized that idiopathic anal sphincter hypertonia was a condition equivalent to anal fissure, and therefore, it could be treated the same way.

PATIENT AND METHODS

Sixty-three patients complaining of anal pain without any anal pathology and ten healthy volunteers were examined. All patients underwent clinical evaluation, neurological examination, anorectal manometry, and measurement of pudendal nerve terminal motor latency. All patients with hypertensive anal canal were randomized into three groups. Group I (surgical group) underwent closed lateral sphincterotomy (LS), group II using nitroglycerine ointment (GTN), and group III received injection of botulinum toxin in internal sphincter. Post-procedures data were recorded at follow-up period.

RESULTS

The mean resting anal pressure (MRAP) was significantly higher in the patient group (114.6 +/- 7.4 mmHg) than control group (72.5 +/- 6.6 mmHg, P < 0.001). Anal pain is the main presenting symptoms aggravated by defecation and not relived by analgesics or local anesthetics. After LS, pain visual analogue scale decreased significantly at follow-up period than after chemical sphincterotomy using GTN or BTX (P = 0.001). There was a significant decrease in MRAP postoperatively from 114.6 +/- 7.4 to 70.8 +/- 5.5 mmHg than after using GTN or BTX (P = 0.03).

CONCLUSION

Idiopathic hypertensive anal canal is a fact and already exists presented by anal pain aggravated by defecation. It can be managed safely by closed lateral sphincterotomy, but chemical sphincterotomy had a minor role in its management.

COX-1 vs. COX-2 as a determinant of basal tone in the internal anal sphincter

Prostanoids, produced endogenously via cyclooxygenases (COXs), have been implicated in the sustained contraction of different smooth muscles. The two major types of COXs are COX-1 and COX-2. The COX subtype involved in the basal state of the internal anal sphincter (IAS) smooth muscle tone is not known. To identify the COX subtype, we examined the effect of COX-1- and COX-2-selective inhibitors, SC-560 and rofecoxib, respectively, on basal tone in the rat IAS. We also determined the effect of selective deletion of COX-1 and COX-2 genes (COX-1(-/-) and COX-2(-/-) mice) on basal tone in murine IAS. Our data show that SC-560 causes significantly more efficacious and potent concentration-dependent decreases in IAS tone than rofecoxib. In support of these data, significantly higher levels of COX-1 than COX-2 mRNA were found in the IAS. In addition, higher levels of COX-1 mRNA and protein were expressed in rat IAS than rectal smooth muscle. In wild-type mice, IAS tone was decreased 41.4 +/- 3.4% (mean +/- SE) by SC-560 (1 x 10(-5) M) and 5.4 +/- 2.2% by rofecoxib (P < 0.05, n = 5). Basal tone was 0.172 +/- 0.021 mN//mg in the IAS from wild-type mice and significantly less (0.080 +/- 0.015 mN/mg) in the IAS from COX-1(-/-) mice (P < 0.05, n = 5). However, basal tone in COX-2(-/-) mice was not significantly different from that in wild-type mice. We conclude that COX-1-related products contribute significantly to IAS tone.

Nonsurgical approaches for the treatment of anal fissures

Chronic anal fissure (CAF) is usually associated with internal anal sphincter spasm, the relief of which is central to provide fissure healing. The treatment for CAF has undergone a transformation in recent years from surgical to medical. Both the approaches share the common goal of reducing the spasm. Though surgical treatment has a high success rate, it can permanently impair fecal continence in a large number of patients. Smooth muscle relaxation seems to be a novel way by which more than 60% of the patients can be cured with the topical use of the agents. This treatment is in addition to the normalization of stools mostly. Smooth muscle relaxation is well tolerated, can be administered on an outpatient basis, does not cause any lesion of the continence organ, and subsequently, does not lead to any permanent latent or apparent fecal incontinence. This review encompasses various agents that are used for smooth muscle relaxation. In addition, it describes various clinical studies reported in the literature with their success rates and side effects.

Current concepts in anal fissures

INTRODUCTION

Anal fissure is a common and distressing problem the true incidence of which is probably higher than recorded. There is a progressive understanding of the etiopathogenesis of this entity and the changing trend in its management approach. This is a systematic review of available published literature looking at current management options in anal fissures.

METHODS

A MEDLINE-based search of the relevant literature from 1970 to 2004 was performed on the current concepts in etiopathogenesis and management of anal fissure.

RESULTS

The current opinion is a drift toward conservative measures as the first- and second-line approaches rather than surgery for treatment of anal fissure. Simple and readily available measures with less complication, good patient compliance, and satisfaction requiring no hospitalization should first be considered.

CONCLUSIONS

Most anal fissures heal with medical therapy, but their limitations include side effects, poor compliance, and recurrence of the fissure. A cautious surgical approach is required to treat those who do not respond to medical therapy.

RhoA Prenylation Inhibitor Produces Relaxation of Tonic Smooth Muscle of Internal Anal Sphincter

RhoA prenylation is a critical step for the translocation of RhoA to the membrane and its activation in response to agonist-induced sustained contraction of the smooth muscle. However, the effect and role of RhoA prenylation in the spontaneously tonic smooth muscle, such as internal anal sphincter (IAS), is not known. Present studies determined RhoA prenylation and its association with the basal tone in the IAS before and after the RhoA prenylation inhibitor, geranylgeranyl transferase inhibitor GGTI-297 [N-4-[2(R)-amino-3-mercaptopropyl]amino-2-naphthylbenzoyl-(L)-leucine,TFA]. Western blot analyses of cytosolic and membrane fractions determined the effects of RhoA prenylation inhibition on the cellular distribution of the RhoA. Additional studies were performed to determine the relationship between RhoA prenylation and Rho kinase (ROCK) activity. GGTI-297 decreased prenylation of RhoA, decreased ROCK activity, and caused a corresponding fall in the IAS tone. These inhibitory effects following RhoA prenylation blockade were demonstrated to be directly on the spontaneously contracted IAS smooth muscle cells. Western blot analysis revealed high levels of RhoA in the IAS smooth muscle cellular membrane in the basal state, and GGTI-297 shifted the RhoA localization to the cytosol. RhoA prenylation may play an important role in the translocation of RhoA to the smooth muscle cell membrane leading to its activation and for the maintenance of basal tone in the IAS.

Rho kinase as a novel molecular therapeutic target for hypertensive internal anal sphincter

BACKGROUND & AIMS

An increase in Rho kinase (ROK) activity has been associated with agonist-induced sustained contraction of the smooth muscle, but its role in the pathophysiology of spontaneously tonic smooth muscle is not known.

METHODS

Present studies examined the effects of ROK inhibitor Y-27632 in the tonic smooth muscle of the rat internal anal sphincter (IAS) versus in the flanking phasic smooth muscle of the rectum. In addition, studies were performed to determine the relationship between the decreases in the basal IAS tone and the ROK activity. Confocal microscopic studies determined the cellular distribution of the smooth muscle-predominant isoform of ROK (ROCK-II) in the smooth muscle cells (SMCs).

RESULTS

In in vitro studies using neurohumoral inhibitors and tetrodotoxin and the use of SMCs demonstrate direct relaxation of the IAS SMCs by Y-27632. The ROK inhibitor was more potent in the IAS than in the rectal smooth muscle. The IAS relaxation by Y-27632 correlated specifically with the decrease in ROK activity. Confocal microscopy revealed high levels of ROCK-II toward the periphery of the IAS SMCs. In in vivo studies, the lower doses of Y-27632 caused a potent and selective decrease in the IAS pressures without any adverse cardiovascular systemic effects. The ROK inhibitor also caused potent relaxation of the hypertensive IAS.

CONCLUSIONS

RhoA/ROK play a crucial role in the maintenance of the basal tone in the IAS, and ROK inhibitors have a therapeutic potential in the IAS dysfunction characterized by the hypertensive IAS.

Management of bladder, prostatic and pelvic floor disorders

Since its introduction in the late 1970s for the treatment of strabismus and blepharospasm, botulinum toxin (BoNT) has been increasingly used in the interventional treatment of several other disorders characterized by excessive or inappropriate muscle contractions. Over the years, the number of primary clinical publications has grown exponentially, and still continues to increase. It has been shown that BoNT blocks cholinergic nerve endings in the autonomic nervous system but does not block non-adrenergic non-cholinergic responses mediated by nitric oxide (NO). The present paper reviews a number of recent clinical indications for urological and pelvic floor dysfunctions, such as overactive and neurogenic bladder, non-bacterial prostatitis, benign prostatic hyperplasia, chronic anal fissure, or conditions associated to hyperactivity of the puborectalis muscle during straining. These indications provide a new promising palette of indications for future usage of BoNT in clinical practice.

Botulinum toxin in dermatology - beyond wrinkles and sweat

Botulinum toxin (BTX) types A and B have been used with success in cosmetic dermatology and hyperhidrosis treatment. The present review focuses on other uses of BTX in dermatology. Discussed in particular are the available data on BTX in inflammatory diseases, proctology, and some other indications. From studies in various types of eczema, it seems that BTX-A not only acts as a potent inhibitor of acetylcholine but also as an inhibitor of substance P and of glutamate as well. By those mechanisms, BTX-A may be antipruritic, which may help explain the benefits of BTX-A in lichen simplex and dyshidrotic hand eczema. In Hailey-Hailey disease, facial eccrine hidrocystomas, salivary fistulas, and intrinsic rhinitis, BTX-A blocks the secretion of sweat/saliva/mucus. BTX-A has important applications in proctology where it has become the most powerful nonsurgical therapy for anal fissures. In proctalgia fugax and after hemorrhoidectomy, BTX-A is analgesic. Current treatment applications of BTX-A and its limitations are reviewed in this paper.

Topical nitroglycerin versus lateral internal sphincterotomy for chronic anal fissure: prospective, randomized trial

INTRODUCTION

Topical nitroglycerin (GTN) is one of the medical treatments of choice in chronic anal fissure. The present prospective, randomized, clinical trial was conducted to study the symptomatic relief, healing, and changes in the maximum anal resting pressure (MARP) in patients with chronic anal fissure comparing topical GTN and lateral sphincterotomy.

METHODS

Forty consecutive patients with chronic anal fissure were randomized for treatment with either topical GTN or internal sphincterotomy (20 patients in each group). Anal manometry was done before treatment in all patients, and 1 h after application of GTN or sphincterotomy. Patients were followed at 2-weekly intervals for 6 weeks for symptomatic relief and healing.

RESULTS

Both GTN and sphincterotomy brought about a highly significant, but comparable drop in the MARP after treatment (P < 0.0001 in both groups). Sphincterotomy relieved pain much earlier compared to GTN (70% vs 40% at 2 weeks, P = 0.0032); but after 4 weeks of treatment, pain relief in both groups was comparable. Healing in the sphincterotomy group was also earlier than with GTN (55% vs 0% at 2 weeks, P < 0.0001; and 85% vs 30% at 4 weeks, P < 0.0001); but after 6 weeks, healing in both groups was comparable. Sphincterotomy had a significant incidence of minor, short-term complications; it also required surgical expertise, theatre time, and day-care beds. Nitroglycerin is safe, with mild and tolerable side-effects of headache and local burning sensation.

CONCLUSION

Topical GTN should be the initial treatment in chronic anal fissure. Lateral sphincterotomy should be reserved for patients with severe disabling pain (because pain relief is much faster), and for patients not responding to at least 4 weeks of GTN therapy.