Neuromyogenic properties of the internal anal sphincter: therapeutic rationale for anal fissures

Use of Botulinum Toxin Injections for the Treatment of Chronic Anal Fissure: Results From an American Society of Colon and Rectal Surgeons Survey

BACKGROUND

Chronic anal fissure (CAF) is commonly treated by colorectal surgeons. Pharmacological treatment is considered first-line therapy. An alternative treatment modality is chemical sphincterotomy with injection of botulinum toxin (BT). However, there is a lack of a consensus on the BT administration procedure among colorectal surgeons.

METHODS

A national survey approved by the American Society of Colon and Rectal Surgeons (ASCRS) Executive Council was sent to all members. An eight-question survey was sent via ASCRS email correspondence between December 2019 and February 2020. Questions were derived from available meta-analyses and expert opinions on BT use in CAF patients and included topics such as BT dose, injection technique, and concomitant therapies. The survey was voluntary and anonymous, and all ASCRS members were eligible to complete it. Responses were recorded and analyzed via an online survey platform.

RESULTS

216 ASCRS members responded to the survey and 90% inject 50-100U of BT. Most procedures are performed under MAC anesthesia (56%). A majority of respondents (64%) inject into the internal sphincter and a majority (53%) inject into 4 quadrants in the anal canal circumference. Some respondents perform concomitant manual dilatation (34%) or fissurectomy (38%). Concomitant topical muscle relaxing agents are not used uniformly among respondents.

DISCUSSION

Injection of BT for CAF is used commonly by colorectal surgeons. There is consensus on BT dosage, administration site, technique, and the use of monitored anesthesia care.

Use of calcium channel blockers in dermatology: a narrative review

Introduction: Calcium channel blockers (CCB) are commonly used for cardiovascular diseases. The evidence supporting the use of CCB in dermatology is mostly anecdotal and limited to case reports or small case series.Areas covered: This review article is divided into two parts. The first part discusses the therapeutic use of CCB in dermatology. The second part focuses on mucocutaneous adverse reactions due to the administration of CCB.Expert opinion: The use of CCB in dermatology is mainly based on its properties as a vasodilator and the inhibition of muscle contractions, such as pernio, anal fissures, facial wrinkles, and painful leiomyoma. However, there remain other modes of action to explain its clinical use in calcinosis, keloid, pressure ulcer, and fibromatosis. Compared to oral CCB, the lack of systemic side effects would make topical use of CCB an attractive alternative in the treatment of skin diseases, but the evidence for topical CCB is still limited, and there is a lack of standardized topical formulation. The main mucocutaneous adverse effects of CCB include gingival hyperplasia, phototoxicity, eczema, psoriasis and risk of skin cancers. Plausible factors for these adverse events include CCB's photoinstability, aldosterone synthesis inhibition, disturbed calcium homeostasis and immunosuppressive properties.

[Anal tone: Physiology, clinical and instrumental characteristics]

INTRODUCTION

The anal tone allows the maintenance of anorectal continence. Its regulation depends on spinal segmental mechanisms under supra-sacral control.

MATERIAL AND METHODS

A systematic review was performed using Medline database, according to PRISMA methodology, using following keywords anal tone ; anal sphincter ; anorectal function ; reflex ; digital rectal examination.

RESULTS

Anal hypertonia is an increase in the muscle's resistance to passive stretching. Muscular hypotonia is a decrease in muscle tone. It is associated with a decrease in resistance to passive mobilization. It is not possible to quantify the prevalence of anal tone alterations in the general population and in specific pathological conditions (urinary disorders, neurogenic or non-neurogenic anorectal disorders). In case of hypotonia, most often due to a lower motor neuron lesion, fecal incontinence may occur. Hypertonia (anal sphincter overactivity) is not always due to perineal spasticity. Indeed, in the majority of the cases, the cause of this anal hypertonia in a neurologic context, can be secondary to an upper motor neuron disease due to spinal or encephalic lesion, leading to recto-anal dyssynergia, giving distal constipation. In another way, this anal hypertonia can be purely behavioral, with no direct pathological significance. The evaluation of anal tone is clinical with validated scores but whose sensitivity is not absolute, and instrumental with, on the one hand, the measurement of anal pressure in manometry and, on the other hand, electrophysiological testing which still require validation in this indication.

CONCLUSION

Anal tone assessment is of interest in clinical practice because it gives diagnostic arguments for the neurological lesion and its level, in the presence of urinary or anorectal symptoms.

Continuous vs stepwise anal acoustic reflectometry: An improved technique for physiological measurement of anal sphincter function?

BACKGROUND

Anal acoustic reflectometry (AAR) is a technique for measuring the physiological profile of the anal canal, primarily the internal anal sphincter. Evaluation of a new continuous method, recently developed for the urethra, would enable its future application for investigation of rectal reflexes.

METHODS

Patients aged 18 and over with fecal incontinence (FI) were included. Stepwise AAR parameters were compared with continuous opening pressure (Op, cmH₂ O), opening elastance (Oe, cmH₂ O/mm² ), closing pressure (Cp, cmH₂ O), closing elastance (Ce, cmH₂ O/mm² ), hysteresis (Hys, [%]), squeeze opening pressure (SqOp, cmH₂ O), and squeeze opening elastance (SqOe, cmH₂ O/mm² ). Vaizey incontinence and Manchester Health Questionnaire scores were also collected.

RESULTS

Thirty-two patients, 26 females were analyzed. Median age: 60 (range, 32-75). Median AAR parameters of Op (37.50 vs 35.15, P = .031), Oe (1.31 vs 0.84, P < .0001), Ce (1.11 vs 0.88, P < .0001), Hys (37.75 vs 19.04, P < .0001), and SqOe (1.27 vs 1.06, P = .005) were significantly higher with the continuous method. Cp (22.70 vs 27.22, P = .003) is lower and SqOp (96.87 vs 59.47, P = .71) not significantly different. The continuous technique had superior repeatability between cycles for all AAR parameters except Oe, which was equivalent and continuous SqOp had a stronger negative correlation with Vaizey score than stepwise (-0.46, P = .009 vs -0.37, P = .038).

CONCLUSIONS

The differences seen between the two techniques are likely to be related to the rate of stretch. The continuous technique appears to represent a more physiological measurement of anal sphincter function than the stepwise technique particularly in the assessment of voluntary squeeze function.

Prolonged-Release Oxycodone/Naloxone Improves Anal Sphincter Relaxation Compared to Oxycodone Plus Macrogol 3350

BACKGROUND

Opioid analgesics inhibit anal sphincter function and contribute to opioid-induced bowel dysfunction (OIBD). However, it is unknown whether the inhibition can be reduced by opioid antagonism with prolonged-release (PR) naloxone and how this compares to laxative treatment.

AIMS

To compare the effects of combined PR oxycodone/naloxone or PR oxycodone plus macrogol 3350 on anal sphincter function and gastrointestinal symptoms.

METHODS

A randomized, double-blind, crossover trial was conducted in 20 healthy men. Participants were treated for 5 days with combined PR oxycodone/naloxone or PR oxycodone plus macrogol 3350. Resting anal pressure, anal canal distensibility, and relaxation of the internal sphincter to rectal distension were evaluated before treatment (baseline) and on day 5. The Patient Assessment of Constipation Symptom (PAC-SYM) questionnaire, stool frequency, and stool consistency were assessed daily.

RESULTS

Both PR oxycodone/naloxone and PR oxycodone plus macrogol treatment decreased sphincter relaxation compared to baseline (- 27.5%; P < 0.001 and - 14.7%; P = 0.01). However, sphincter relaxation was increased after PR naloxone/oxycodone treatment compared to macrogol (difference = + 17.6%; P < 0.001). Resting anal pressure and anal canal distensibility did not differ between treatments. PAC-SYM abdominal symptoms score was lower during PR naloxone compared to macrogol (0.2 vs. 3.2; P = 0.002). The number of bowel movements was lower during PR naloxone versus macrogol (4.2 vs. 5.4; P = 0.035).

CONCLUSION

Relaxation of the internal anal sphincter was significantly better after PR oxycodone/naloxone treatment compared to PR oxycodone plus macrogol 3350. These findings highlight that OIBD may require specific therapy against the complex, pan-intestinal effects of opioids.

Role of differentially expressed microRNA-139-5p in the regulation of phenotypic internal anal sphincter smooth muscle tone

The present study focused on the role of microRNA-139-5p (miRNA-139-5p) in the regulation of basal tone in internal anal sphincter (IAS). Applying genome-wide miRNA microarrays on the phenotypically distinct smooth muscle cells (SMCs) within the rat anorectrum, we identified miRNA-139-5p as differentially expressed RNA repressor with highest expression in the purely phasic smooth muscle of anococcygeus (ASM) vs. the truly tonic smooth muscle of IAS. This pattern of miRNA-139-5p expression, previously shown to target ROCK2, was validated by target prediction using ingenuity pathway (IPA) and by qPCR analyses. Immunoblotting, immunocytochemistry (ICC), and functional assays using IAS tissues and cells subjected to overexpression/knockdown of miRNA-139-5p confirmed the inverse relationship between miRNA-139-5p and ROCK2 expressions/IAS tone. Overexpression of miRNA-139-5p caused a decrease, while knockdown by anti-miRNA-139-5p caused an increase in the IAS tone; these tissue contractile responses were confirmed by single-cell contraction using magnetic twisting cytometry (MTC). These findings suggest miRNA-139-5p is capable of significantly influencing the phenotypic tonicity in smooth muscle via ROCK2: a lack of tone in ASM may be associated with the suppression of ROCK2 by high expression of miRNA-139-5p, whereas basal IAS tone may be associated with the persistence of ROCK2 due to low expression of miRNA-139-5p.

Internal anal sphincter: Clinical perspective

OBJECTIVE

To summarise current knowledge of Internal anal sphincter.

BACKGROUND

The internal anal sphincter (IAS) is the involuntary ring of smooth muscle in the anal canal and is the major contributor to the resting pressure in the anus. Structural injury or functional weakness of the muscle results in passive incontinence of faeces and flatus. With advent of new assessment and treatment modalities IAS has become an important topic for surgeons. This review was undertaken to summarise our current knowledge of internal anal sphincter and highlight the areas that need further research.

METHOD

The PubMed database was used to identify relevant studies relating to internal anal sphincter.

RESULTS

The available evidence has been summarised and advantages and limitations highlighted for the different diagnostic and therapeutic techniques.

CONCLUSION

Our understanding of the physiology and pharmacology of IAS has increased greatly in the last three decades. Additionally, there has been a rise in diagnostic and therapeutic techniques specifically targeting the IAS. Although these are promising, future research is required before these can be incorporated into the management algorithm.

Anal fissure and stenosis

Anal fissure is a common anorectal disorder resulting in anal pain and bleeding. Fissures can either heal spontaneously and be classified as acute, or persist for 6 or more weeks and be classified as chronic, ultimately necessitating treatment. Anal stenosis is a challenging problem most commonly resulting from trauma, such as excisional hemorrhoidectomy. This frustrating issue for the patient is equally as challenging to the surgeon. This article reviews these 2 anorectal disorders, covering their etiology, mechanism of disease, diagnosis, and algorithm of management.

Bioengineered human IAS reconstructs with functional and molecular properties similar to intact IAS

Because of its critical importance in rectoanal incontinence, we determined the feasibility to reconstruct internal anal sphincter (IAS) from human IAS smooth muscle cells (SMCs) with functional and molecular attributes similar to the intact sphincter. The reconstructs were developed using SMCs from the circular smooth muscle layer of the human IAS, grown in smooth muscle differentiation media under sterile conditions in Sylgard-coated tissue culture plates with central Sylgard posts. The basal tone in the reconstructs and its changes were recorded following 0 Ca(2+), KCl, bethanechol, isoproterenol, protein kinase C (PKC) activator phorbol 12,13-dibutyrate, and Rho kinase (ROCK) and PKC inhibitors Y-27632 and Gö-6850, respectively. Western blot (WB), immunofluorescence (IF), and immunocytochemical (IC) analyses were also performed. The reconstructs developed spontaneous tone (0.68 ± 0.26 mN). Bethanechol (a muscarinic agonist) and K(+) depolarization produced contraction, whereas isoproterenol (β-adrenoceptor agonist) and Y-27632 produced a concentration-dependent decrease in the tone. Maximal decrease in basal tone with Y-27632 and Gö-6850 (each 10(-5) M) was 80.45 ± 3.29 and 17.76 ± 3.50%, respectively. WB data with the IAS constructs' SMCs revealed higher levels of RhoA/ROCK, protein kinase C-potentiated inhibitor or inhibitory phosphoprotein for myosin phosphatase (CPI-17), phospho-CPI-17, MYPT1, and 20-kDa myosin light chain vs. rectal smooth muscle. WB, IF, and IC studies of original SMCs and redispersed from the reconstructs for the relative distribution of different signal transduction proteins confirmed the feasibility of reconstruction of IAS with functional properties similar to intact IAS and demonstrated the development of myogenic tone with critical dependence on RhoA/ROCK. We conclude that it is feasible to bioengineer IAS constructs using human IAS SMCs that behave like intact IAS.

Anal fissure

Anal fissure is one of the most common anorectal problems. Anal fissure is largely associated with high anal sphincter pressures and most treatment options are based on reducing anal pressures. Conservative management, using increased fiber and warm baths, results in healing of approximately half of all anal fissures. In fissures that fail conservative care, various pharmacologic and surgical options offer satisfactory cure rates. Lateral internal sphincterotomy remains the gold standard for definitive management of anal fissure. This review outlines the key points in the presentation, pathophysiology, and management of anal fissure.

Internal anal sphincter parasympathetic-nitrergic and sympathetic-adrenergic innervation: a 3-dimensional morphological and functional analysis

BACKGROUND

Little detailed information is available concerning morphological and functional autonomic nerve supply to the internal anal sphincter. However, denervation of the sphincter potentially affects anal function after rectal surgery for cancer.

OBJECTIVE

The aim of this study was to identify the location and type (nitrergic, adrenergic, and cholinergic) of nerve fibers in the internal anal sphincter and to provide a 3-dimensional representation of their structural relationship in the human fetus.

MATERIALS AND METHODS

serial transverse sections were obtained from 14 human fetuses (7 male, 7 female, 15-31 weeks of gestation) and were studied histologically and immunohistochemically; digitized serial sections were used to construct a 3-dimensional representation of the pelvis.

MAIN OUTCOMES MEASURES

The location and type of internal anal sphincter nerves were assessed qualitatively.

RESULTS

Posteroinferior fibers originating from the inferior hypogastric plexus posteroinferior angle projected to the posterolateral and posterior rectal wall and internal anal sphincter, forming the inferior rectal plexus. The inferior rectal plexus contained vesicular acetylcholine transporter-positive (cholinergic), tyrosine hydroxylase-positive (adrenergic/sympathetic), and neural nitric oxide synthase-positive (nitrergic) fibers. The intrasphincteric vesicular acetylcholine transporter-positive fibers included both neural nitric oxide synthase-negative fibers and neural nitric oxide synthase-positive fibers (nitrergic-parasympathetic).

LIMITATIONS

The study focused on topographic and functional anatomy, so that quantitative data were not obtained. A small number of fetal specimens were available.

CONCLUSIONS

We report the precise location and distribution of the autonomic neural supply to the internal anal sphincter. This description contributes to the understanding of neurogenic postoperative sphincteric dysfunction. Three-dimensional cartography of pelvic-perineal neurotransmitters provides an anatomical and physiological basis for the selection and development of pharmacological agents to be used in the treatment of primary or postoperative continence and evacuation disorders.

RhoA/ROCK pathway is the major molecular determinant of basal tone in intact human internal anal sphincter

The knowledge of molecular control mechanisms underlying the basal tone in the intact human internal anal sphincter (IAS) is critical for the pathophysiology and rational therapy for a number of debilitating rectoanal motility disorders. We determined the role of RhoA/ROCK and PKC pathways by comparing the effects of ROCK- and PKC-selective inhibitors Y 27632 and Gö 6850 (10(-8) to 10(-4) M), respectively, on the basal tone in the IAS vs. the rectal smooth muscle (RSM). Western blot studies were performed to determine the levels of RhoA/ROCK II, PKC-α, MYPT1, CPI-17, and MLC(20) in the unphosphorylated and phosphorylated forms, in the IAS vs. RSM. Confocal microscopic studies validated the membrane distribution of ROCK II. Finally, to confirm a direct relationship, we examined the enzymatic activities and changes in the basal IAS tone and p-MYPT1, p-CPI-17, and p-MLC(20), before and after Y 27632 and Gö 6850. Data show higher levels of RhoA/ROCK II and related downstream signal transduction proteins in the IAS vs. RSM. In addition, data show a significant correlation between the active RhoA/ROCK levels, ROCK enzymatic activity, downstream proteins, and basal IAS tone, before and after ROCK inhibitor. From these data we conclude 1) RhoA/ROCK and downstream signaling are constitutively active in the IAS, and this pathway (in contrast with PKC) is the critical determinant of the basal tone in intact human IAS; and 2) RhoA and ROCK are potential therapeutic targets for a number of rectoanal motility disorders for which currently there is no satisfactory treatment.

Pharmacological sphincterotomy for chronic anal fissures by botulinum toxin a

Chronic anal fissure is a common proctologic disease. Botulinum toxin (BTX) can be used for temporary chemical denervation to treat this painful disorder. Its application is by intramuscular injections into either the external or internal anal sphincter muscle. The mode of action, application techniques, and possible complications or adverse effects of BTX therapy are discussed in this report. The healing rate is dependent on the BTX dosage. The short-term healing rate (</= 6 months) is 60-90%, whereas about 50% of the patients show a complete response in long-term follow-up studies (> 1 year). Adverse effects are generally mild, but relapses occur more often than with surgery. Conservative therapy is currently considered as a first-line treatment. With increasing evidence for its efficacy, BTX can now be considered among the first-line nonsurgical treatements. Although, surgical management by lateral sphincterotomy is the most effective treatment, it shows a higher incidence of incontinence and greater general morbidity rate than BTX. BTX is a useful alternative to surgery and in many cases, surgery can be avoided with the use of BTX.

Basal internal anal sphincter tone, inhibitory neurotransmission, and other factors contributing to the maintenance of high pressures in the anal canal

Maintenance of the basal tone in the internal anal sphincter (IAS) is critical for rectoanal continence. Effective evacuation requires a fully functional rectoanal inhibitory reflex (RAIR)-mediated relaxation of the IAS via inhibitory neurotransmission (INT). Systematic studies examining the nature of the INT in different species have identified nitric oxide (NO) as the major inhibitory neurotransmitter. However, other mediators such as vasoactive intestinal polypeptide (VIP), ATP, and carbon monoxide (CO) may also play species-specific role under certain experimental conditions. Measurements of the intraluminal pressures in the IAS along with the force of the isolated IAS tissues are the mainstay in the basic studies for the molecular mechanisms underlying the basal tone and in the nature of the INT. The identification of NO as the inhibitory neurotransmitter has led to major advances in the diagnosis and treatment of a number of rectoanal motility disorders associated with the IAS dysfunction. Besides the IAS, the high pressures in the anal canal are affected by the external anal sphincter (EAS) function, and its malfunction may also lead to rectoanal incontinence. Different approaches including biofeedback have been attempted to improve the EAS function, with variable outcomes. There is a dire need for the innovative ways to improve the week high pressures zone in the anal canal. This viewpoint focuses on two studies that extend the above concept of multiplicity of inhibitory neurotransmitters (Neurogastroenterol Motil 2011 23 e11–25), and that high pressures in the anal canal can be improved by the EAS plication (Neurogastroenterol Motil 2011 23 70–5).

Faecal incontinence after seton treatment for anal fistulae with and without surgical division of internal anal sphincter: a systematic review

OBJECTIVE

The challenge of surgery for anal fistula is to eradicate the fistula track while maintaining anal continence. Seton placement is recommended to reduce postoperative faecal incontinence but interestingly a great range of functional impairment after surgery has been published. The aim of this study was to analyse the influence of intra-operative internal anal sphincter division during tight or cutting seton technique for cryptogenic anal fistula, on the results of recurrence and postoperative faecal incontinence.

METHOD

A systematic literature review was performed to identify published series from 1966 to May 2007 of patients with anal fistula treated by a tight or cutting seton technique. The published series has been divided in to those where preservation of internal anal sphincter was performed (PIAS group) or where intra-operative surgical division was undertaken in the time of seton placement (SIAS group) .The main endpoints of the review were to study anal fistula recurrence rate and postoperative faecal incontinence.

RESULTS

Eighteen studies including 19 series and 448 patients were analysed in detail. Recurrence rate was 5.0% and 3.0% in PIAS and SIAS group respectively. Overall faecal incontinence rate was 5.6% in PIAS group and 25.2% in SIAS group.

CONCLUSION

Although based on low-evidence studies, intra-operative preservation of internal anal sphincter at the time of seton insertion for anal fistula seems to reduce the postoperative faecal incontinence without a substantial increase in recurrence rates.

A comparative study of structure and function of the longitudinal muscle of the anal canal and the internal anal sphincter in pigs

PURPOSE

This study aims to compare the physiology of the longitudinal muscle of the anal canal with the internal anal sphincter in pigs.

METHODS

Histology and in vitro studies were performed to compare the effect of neural responses induced by electric stimulation and through nicotinic, purinergic, and serotoninergic receptors.

RESULTS

The longitudinal muscle and the internal anal sphincter are constituted exclusively by smooth muscle. Strips from the internal anal sphincter a) developed myogenic tone; b) responded to electric stimulation with an "on" relaxation antagonized by nitric oxide synthase inhibitors and purinergic P2Y1 antagonists, and with an "off" contraction antagonized by atropine and phentolamine; and c) responded to stimulation of nicotinic receptors with a relaxation antagonized by nitrergic and purinergic P2Y1 antagonists, responded to stimulation of serotoninergic 5-hydroxytryptamine 3 receptors with a contraction, and relaxed to carbachol and purinergic P2X agonists. Strips from the longitudinal muscle a) did not develop tone, b) responded to electric stimulation with an "on" contraction antagonized by atropine, and c) did not respond to stimulation of nicotinic or serotoninergic 5-hydroxytryptamine 3 receptors, and carbachol and purinergic P2X agonists induced a contraction.

CONCLUSIONS

The motility of the internal anal sphincter includes myogenic tone, relaxation mediated by nitric oxide and purinergic P2Y1 receptors, and contraction mediated by cholinergic motor neurons and sympathetic fibers. The motility of the longitudinal muscle is limited to a contraction mediated by cholinergic neurons, suggesting that longitudinal muscle contracts during relaxation of the internal sphincter, shortening the anal canal. Nicotinic, muscarinic, and serotoninergic receptors might be therapeutic targets for anal motor disorders.

Investigation of the role of adrenergic and non-nitrergic, non-adrenergic neurotransmission in the sheep isolated internal anal sphincter

Nitric oxide is widely established as an important neurotransmitter in the control of anal sphincter tone; although, a number of other transmitters have also been tentatively implicated. Whilst alpha-adrenoceptor antagonists reduce anal sphincter pressure in man, the role of noradrenaline as a possible transmitter is poorly characterised. We have investigated the contribution of these transmitters to neurogenic relaxations, and evaluated the possible role of a non-nitrergic, non-adrenergic transmitter. The magnitude and duration of neurogenic responses were examined by measuring responses to electrical field stimulation (EFS) in segments of sheep internal anal sphincter following the development of spontaneous myogenic tone. Neurogenic relaxations induced by EFS were significantly reduced in the presence of N(G)-nitro-L-arginine methyl ester (L-NAME) suggesting major involvement of nitric oxide as a neurotransmitter. The duration of neurogenic relaxations was inversely related to the frequency of EFS, with contractile responses often manifest at higher frequencies. The duration of relaxations at high frequencies of EFS was increased by bretylium (adrenergic neurone blocker) and prazosin (alpha(1)-adrenoceptor antagonist). At higher frequencies of EFS, 60% of preparations also produced a residual non-nitrergic, non-adrenergic, apamin-sensitive relaxation which was unaffected by vasoactive intestinal polypeptide (VIP) and inhibitors of purinergic responses [suramin, pyridoxal-phosphate-6-azophenyl 2',4' disulfonic acid (PPADS) and alpha,beta-methylene adenosine triphosphate (ATP)]. However, MRS2179 (P2Y(1) receptor antagonist) showed a modest inhibitory effect. We conclude that endogenous noradrenaline acts via postjunctional alpha(1)-adrenoceptors to antagonize neurogenic relaxations that are largely mediated by nitric oxide. Our results indicate the involvement of a non-nitrergic, non-adrenergic, apamin-sensitive transmitter which is inhibited by MRS2179, suggesting a possible role for purines.

Anal ultraslow waves and high anal pressure in childhood: a clinical condition mimicking Hirschsprung disease

PURPOSE

Anal ultraslow waves (USWs) have been described in several clinical conditions closely related to chronic constipation associated with high anal pressure; however, USW-related clinical manifestations in childhood are poorly understood. The purpose of this study is to elucidate the clinical relevance of USWs in childhood.

METHODS

Manometric recordings of 118 cases including 70 children with constipation and 16 patients with Hirschsprung disease were analyzed.

RESULTS

Ultraslow waves were seen in 4 of 70 children with constipation. None of the controls or patients with Hirschsprung disease exhibited USWs. The 4 patients comprised 2 infants with marked abdominal distension mimicking Hirschsprung disease and 2 children (aged 4 and 8 years) with intractable constipation accompanying hemorrhoid or anal fissure. The manometric findings of the USW-positive patients showed a markedly high anal resting pressure and high frequency of slow waves compared to controls, patients with constipation not accompanied by USWs or patients with Hirschsprung disease.

CONCLUSION

Children with USWs exhibit symptoms mimicking Hirschsprung disease in infants and chronic intractable constipation in older children. In manometric studies of children, more attention should be paid not only to rectoanal reflex, but also USWs.

Multiple clinical presentations of anal ultra slow waves and high anal pressure: megacolon, hemorrhoids and constipation

The physiopathology of idiopathic chronic constipation is complex and yet to be investigated. In the manometric studies of the patients with severe chronic constipation, we noticed that some patients with megacolon show very slow periodical (< 2/min) pressure change in the anal canal, namely ultra slow waves (USWs). USWs are considered to represent the hyperactivity of the internal anal sphincter; however, USW-related clinical presentations have yet to be investigated. We retrospectively re-evaluated the patient records and manometric studies of 85 cases, 51 subjects without defecatory problems and 34 patients with constipation, to elucidate USW-related clinical presentations. USWs were seen in 10 patients, including eight patients with chronic constipation and two subjects without defecatory problems. Out of the eight patients with constipation, one had no organic change in the anorectum, three had hemorrhoids and four exhibited megacolon. Manometric and pathological studies proved that none of the four patients with megacolon was suffering from Hirschsprung's disease. Among the 51 subjects without defecatory problems, only two had USWs. Anal pressure in the USW-positive group (106.0 +/- 37.0 cmH2O) was significantly higher than that in the group without defecatory problems (56.0 +/- 27.0 cmH2O) or constipated patients without USWs (55.0 +/- 26.0 cmH2O). Megacolon and high anal pressure, as well as chronic constipation and hemorrhoids, were the clinical presentations related to USWs. This is the first report to show the clinical relevance of USWs to megacolon. USWs should be recognized as an important manometric finding indicating a possible new clinical entity in chronic constipation.

0.4% nitroglycerin ointment : in the treatment of chronic anal fissure pain

0.4% Nitroglycerin ointment is an intra-anal formulation of nitroglycerin (glyceryl trinitrate) indicated for the treatment of chronic anal fissure pain.black triangle Nitroglycerin is a nitric oxide (NO) donor, which reduces the increased anal canal pressure caused by a hypertonic internal anal sphincter, improving anodermal blood flow. A twice-daily 375 mg application of 0.4% nitroglycerin ointment, delivering a daily nitroglycerin dose of 3mg, significantly increased the rate of decrease in mean visual-analogue-scale pain scores, recorded daily, versus placebo (actual vehicle) over the first 3 and 8 weeks of treatment in patients with chronic anal fissure pain participating in randomised double-blind trials. Most recipients of 0.4% nitroglycerin ointment experienced headache, which was transient but severe in 20-25% of patients in randomised double-blind trials; however, compliance was generally good with few study withdrawals. Features and properties of 0.4% nitroglycerin (Rectogesic) rectal ointment Indication Pain associated with chronic anal fissures Mechanism of action Donor of nitric oxide Mediates relaxation of internal anal sphincter Dosage and administration Dosage 375 mg of 0.4% nitroglycerin rectal ointment, delivering nitroglycerin 1.5 mg Frequency Twice daily Route of administration Intra-anal Pharmacokinetic profile Mean bioavailability (0.2% nitroglycerin ointment, 0.75 mg nitroglycerin dose)50%Maximum plasma concentration 0.1 to >1 microg/L Volume of distribution approximate, equals 3 L/kg Clearance approximate, equals 1 L/kg/min Elimination half-life approximate, equals 3 min Most common adverse event Headache.

Topical 0.5% nifedipine vs. lateral internal sphincterotomy for the treatment of chronic anal fissure: long-term follow-up

BACKGROUND

The aim of this study was to compare the efficacy of the local application of 0.5% nifedipine ointment vs. lateral internal sphincterotomy in the healing of chronic anal fissure.

PATIENTS AND METHODS

Sixty-four patients with symptomatic chronic anal fissures were randomly assigned to 0.5% nifedipine ointment (n=32) every 8 h for 8 weeks or lateral internal sphincterotomy (n=32). Both groups received stool softeners and fiber supplements and were assessed at 2, 4, 6, and 8 weeks. Long-term outcomes were determined after a median follow-up of 19 months (nifedipine group) and 20.5 months (lateral internal sphincterotomy group).

RESULTS

Complete healing at 8 weeks was achieved in 30 out of 31 patients (96.7%) in the nifedipine group and 32 out of 32 patients (100%) in the lateral internal sphincterotomy group (p=0.49). The overall healing rates at the end of follow-up were 28 out of 30 (93%) vs. 32 out of 32 (100%) in the nifedipine and sphincterotomy groups respectively (p=0.48). Two of the 30 patients in the nifedipine group relapsed whereas none in the sphincterotomy group did. Sixteen patients (50%) developed side effects in the nifedipine group, compared with six patients (18.7%) in the sphincterotomy group.

CONCLUSIONS

Topical application of 0.5% nifedipine ointment represents a new, promising, easily handled, effective alternative to lateral internal sphincterotomy.

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.

Early Results of a Rotation Flap to Treat Chronic Anal Fissures

BACKGROUND

Treatment of anal fissures has changed dramatically in the past decade. This is primarily due to a better understanding of its pathophysiology and the implications of the various available options. Only a few anal fissures fail to respond to medical therapy. Sphincterotomy and anal dilatation have fallen out of favour due to the risk of incontinence. Island flaps have been proposed to address this, but 60-70% of the flap donor sites break down with complications. We propose using a rotation flap to overcome this problem.

METHODS

A local rotation flap from perianal skin was used to fill the fissure defect in 14 patients who were followed up for a period of 6 months to determine fissure healing and incidence of donor site breakdown.

RESULTS

Twelve patients had complete resolution of their symptoms. Of two patients who developed fissure recurrence, one also had dehiscence of the donor site. There were no donor site complications in the remaining patients. No patient suffered continence defects as a result of the surgery.

CONCLUSION

Rotation flap is a simple, safe and appropriate modality for treating chronic anal fissures. Donor site problems are avoided using this approach. It should be the treatment of choice, particularly in patients who are at risk of incontinence.

Early results of a rotational flap to treat chronic anal fissures

BACKGROUND

Treatment of anal fissures has changed dramatically in the past decade. Only a few fail to respond to medical therapy. Sphincterotomy and anal dilatation have fallen out of favour due to the risk of incontinence. Island flaps have been proposed to address this, but 60--70% of flap donor sites break down with complications. We proposed that using a rotational flap would overcome this problem.

METHODS

Twenty-one patients (14 women,7 men) with chronic anal fissures were treated with rotation flap from perianal skin. The median age was 43 (range 21--76) years. All patients had failed chemical sphincterotomy and showed no signs of improvement following at least a 3-month course of topical GTN 0.2% ointment.

RESULTS

The median hospital stay was 2 days. Seventeen patients had complete resolution of symptoms. Only one patient continued to have severe pain. Two developed a recurrent fissure. One patient had a combined fistula-fissure complex at diagnosis and suffered from a breakdown of the flap and donor site. Another patient had had haemorrhoidectomy and an advancement flap in the past. He developed problems with the donor site, which was successfully managed conservatively. One patient had persistent mild pain after surgery, but the cause could not be found. None of the patients suffered continence defects after surgery.

CONCLUSION

Use of a rotational flap is a simple, safe and successful treatment for anal fissures. Donor site problems are minimised using this approach. It should be a treatment of choice when surgery is required for chronic anal fissures, particularly in patients in whom there is a risk of incontinence.

Randomized clinical trial comparing oral nifedipine with lateral anal sphincterotomy and tailored sphincterotomy in the treatment of chronic anal fissure

BACKGROUND

The conventional treatment of chronic anal fissure is lateral sphincterotomy (LAS). The alternative options of tailored sphincterotomy (TS) and 'chemical sphincterotomy' using medication such as nifedipine have recently become available.

METHODS

A prospective randomized trial was conducted to compare LAS with TS and oral nifedipine. The main endpoints were fissure healing, symptom relief, recurrence and continence.

RESULTS

One hundred and thirty-two patients were treated and followed up for 4 months. LAS was significantly more effective than TS in providing pain relief (P = 0.004) and better patient satisfaction (P = 0.020) at 4 weeks. Surgery (LAS and TS) was associated with significantly better fissure healing rates (both P < 0.001 at 16 weeks) and less recurrence (both P = 0.003) than nifedipine. There were substantial problems with compliance in the nifedipine group (17 of 41 patients), related to side-effects and slow healing. There were no differences in continence between the three treatment groups.

CONCLUSION

LAS was most effective in providing pain relief and allowing rapid fissure healing, with minimal recurrence and no increased risk of incontinence, in patients with good anal sphincter function.

Treating chronic anal fissure with botulinum neurotoxin

Recent reports confirm that the management of chronic anal fissure has undergone extensive re-evaluation during the past few years. This rejuvenation of interest is attributable to the application of neurochemical treatment, which has contributed to the tendency to treat the disease on an outpatient basis. The use of botulinum neurotoxin seems to be a promising and safe approach for the treatment of chronic anal fissure, particularly in patients at high risk for incontinence. Indeed, botulinum neurotoxin has been successfully used selectively to weaken the internal anal sphincter as a treatment for chronic anal fissure. It is also more efficacious than nitrate therapy, and is not related to the patient's willingness to complete treatment.

Differential effects of two types of antidepressants, amitriptyline and fluoxetine, on anorectal motility and visceral perception

BACKGROUND

Although antidepressants are used for functional gastrointestinal disorders, the mechanisms of their effects on gut are incompletely understood.

AIM

To assess the effects of two types of antidepressants (tricyclic, serotoninergic) on anorectal motility and visceral perception.

METHODS

A placebo-controlled, randomized, double-blind, crossover study was performed in 12 healthy male volunteers who received a single oral dose of amitriptyline (80 mg), fluoxetine (40 mg) or placebo. Drug effects were assessed using phasic isobaric distensions of the rectum with an electronic barostat (11 levels from 1 to 51 mmHg) 4 h after drug intake. Maximal rectal volume and pressure, mean and residual pressures at upper anal canal, mean pressure at lower anal canal, defecation sensation (5-level scale) and visceral perception (visual analogue scale) were recorded at each level of distending pressure.

RESULTS

Ten subjects completed the study. Compared with placebo, neither amitriptyline nor fluoxetine modified rectal compliance or visceral perception. Compared with placebo, antidepressants significantly reduced mean and residual pressures at upper anal canal (-18%, P = 0.0019, and -27%, P = 0.0002, respectively, for amitriptyline; -26%, P = 0.0001, and -33%, P = 0.0001, respectively, for fluoxetine) whereas only amitriptyline significantly reduced mean pressure at lower anal canal (-16%, P = 0.0008).

CONCLUSION

Both antidepressants similarly relaxed the internal anal sphincter, probably through a non-specific mechanism, without modifying visceral perception. Only amitriptyline relaxed the external anal sphincter.

Treatment with botulinum neurotoxin of gastrointestinal smooth muscles and sphincters spasms

Local injections of botulinum neurotoxin are now considered an efficacious treatment for neurological and non-neurological conditions. One of the most recent achievements in the field is the observation that botulinum neurotoxin provides benefit in diseases of the gastrointestinal tract. Botulinum neurotoxin inhibits contraction of gastrointestinal smooth muscles and sphincters; it has also been shown that the neurotoxin blocks cholinergic nerve endings in the autonomic nervous system, but it does not block nonadrenergic responses mediated by nitric oxide. This aspect has further promoted the interest to use botulinum neurotoxin as a treatment for overactive smooth muscles, such as the anal sphincters to treat anal fissure and outlet-type constipation, or the lower esophageal sphincter to treat esophageal achalasia. Knowledge of the anatomical and functional organization of innervation of the gastrointestinal tract is a prerequisite to understanding many features of botulinum neurotoxin action on the gut and the effects of injections placed into specific sphincters. This review presents current data on the use of botulinum neurotoxin to treat diseases of the gastrointestinal tract and summarizes recent knowledge on the pathogenesis of disorders of the gut due to a dysfunction of the enteric nervous system.

Attitudes to the treatment of chronic anal fissure in ano after failed medical treatment

OBJECTIVE

The treatment of chronic fissure may be medical or surgical. Indications for assessment, which is the better treatment and under what circumstances, are vital for the appropriate management. The aim of the study was to assess the management of this condition by an expert group of surgeons.

METHODS

Consultant members of the Association of Coloproctology of Great Britain and Ireland (n=452) were approached and requested to answer a preset multiple-choice questionnaire. The questionnaire was designed to assess their management strategy and their approach to investigation and treatment under different clinical situations.

RESULTS

The overall response was 78% (n = 356). Medical treatment was the first line treatment in 95% of the responders. Lateral anal sphincterotomy without pre-operative endoanal ultrasound and/or anorectal physiology was performed by 57%. Anal dilatation was performed selectively by 36% but only 35% of these would perform a pre-operative endoanal ultrasound or anorectal physiology.

CONCLUSION

In the selected group of clinicians lateral anal sphincterotomy remains the procedure of choice in both sexes. Pre-operative assessment using endoanal ultrasound and anorectal physiology is used selectively especially in postpartum women. Anal dilatation remains a subjective procedure and though used selectively, is performed without pre-operative endoanal ultrasound and/or anorectal physiology in majority of cases.

Concepts in pathogenesis and treatment of chronic anal fissure--a review of the literature

OBJECTIVE

Chronic anal fissures are associated with a persistent hypertonia and spasm of the internal anal sphincter. Classic treatment is surgical sphincterotomy to reduce the anal tone and eliminate sphincteric spasm. However, concerns have been raised about the incidence of fecal incontinence after surgery. Therefore, pharmacological means to treat chronic anal fissures have been explored.

METHODS

We conducted a literature review on MEDLINE database.

RESULTS

All treatments address the anomaly of a high anal pressure. Several studies have investigated the effect of topical glyceryl trinitrate ointment. Healing rates range from 30% to 86%. Therapy is limited because of a high incidence of moderate to severe headaches in up to 84% of patients. Comparable results are observed after injection of botulinum toxin into the anal sphincter (43-96%). Minor incontinence for flatus and soiling has been reported in up to 12% of patients. Further pharmacological approaches including treatment via calcium channel blockade and treatment with alpha-adrenoceptor antagonists are still at a developmental stage.

CONCLUSIONS

Topical glyceryl trinitrate ointment and injection of botulinum toxin into the anal sphincter are advocated as the first-line treatment for chronic anal fissure. Lateral sphincterotomy should be offered to patients with relapse and therapeutic failure of prior pharmacological treatment.

Botulinum neurotoxin and other treatments for fissure-in-ano and pelvic floor disorders

BACKGROUND

The management of disorders of the lower gastrointestinal tract, such as chronic anal fissure and pelvic floor dysfunction, has undergone re-evaluation recently. To a large extent this is due to the advent of neurochemical treatments, such as botulinum neurotoxin injections and topical nitrate ointment.

METHODS AND RESULTS

This review presents, inter alia, current data on the use of botulinum neurotoxin to treat lower gastrointestinal tract diseases, such as chronic anal fissure for which it promotes healing and symptom relief in up to 70 per cent of cases. This agent has also been used selectively to weaken the external anal sphincter and puborectalis muscle in constipation and in Parkinson's disease. Symptomatic improvement can also be induced in anterior rectocele by botulinum neurotoxin injections.

CONCLUSION

Botulinum neurotoxin appears to be a safe therapy for anal fissure. It is more efficacious than nitrate application and does not require patient compliance to complete treatment. While it may also be a promising approach for the treatment of chronic constipation due to pelvic floor dysfunction, further investigation of its efficacy and safety in this role is needed before general usage can be advocated.

Chest pain of esophageal origin

Chest pain of esophageal origin is the most common atypical/extraesophageal manifestation of gastroesophageal reflux disease (GERD). We are increasingly recognizing the important role of the cardiologist in making the diagnosis. Studies continue to focus on the mechanisms of pain in this challenging group of patients. Factors that determine the development and persistence of visceral hypersensitivity are currently under investigation. Invasive diagnostic studies have been replaced by therapeutic trials or empirical therapies. Proton pump inhibitors have been demonstrated to be the most effective treatment for GERD-related noncardiac chest pain (NCCP). Pain modulators remain the primary therapy for non-GERD-related NCCP. Sertraline is the first selective serotonin reuptake inhibitor to demonstrate a significant improvement in chest pain symptoms.

Treatment of anal fissures with topical nitroglycerin

Anal fissure is a painful condition that is caused by anodermal tearing after the passage of hard stool. Severe cases result in involuntary internal anal sphincter spasm and have traditionally been treated surgically with a lateral sphincterotomy. Investigators have demonstrated that nitric oxide causes relaxation of the smooth muscle of the anal canal, so topical nitroglycerin ointment preparations have recently been studied as an efficacious alternative to surgery. Despite the fact that there are a number of trials examining topical nitroglycerin for the treatment of anal fissures, there remains no consensus about concentrations, compositions and applications necessary to obtain good results. This review summarises current literature regarding topical nitroglycerin pharmacotherapy for anal fissure.