Fissure in Ano - The Evidence

Rick Nelson

Powerpoint File

The most consistent finding in typical fissures is spasm of the internal anal sphincter, which is so severe that the pain caused by fissure is thought to be due to ischemia1,2. Relief of the spasm has been associated with relief of pain and healing of the fissure without recurrence. Historically, the most common approach for relieving the spasm has been surgical. Operative techniques commonly used for chronic fissure in ano include anal stretch, open lateral sphincterotomy, closed lateral sphincterotomy, posterior midline sphincterotomy, and to a lesser extent, dermal flap coverage of the fissure.

Morbidity from these procedures, being principally incontinence, was once thought to be extremely rare3, but has been substantial in some more recent reports4, generating enthusiasm for therapies that do not involve sphincter division. A recent Cochrane review has assessed the efficacy and morbidity of operative therapy for anal fissure5. This review has been updated as of February, 2005. In that review, and in subsequent publications with sufficient follow-up, cure was achieved by sphincterotomy in greater than 90% of patients, and incontinence risk has been about 10%6. Two publications have found that patients felt their quality of life was greatly improved by sphincterotomy7,8. Yet this concern about incontinence after surgery has led to increasing interest in alternative therapies that might diminish incontinence risk. This field has developed with great speed over the past ten years.

Up to ten years ago, non-surgical therapy for anal fissure consisted of lubricants, laxatives, anti-inflammatories and anesthetics. It was generally felt that these therapies were palliative for chronic fissure and only effective in achieving cure in acute fissure and fissure of any age in children. The concept of a chemical sphincterotomy, of achieving a temporary relaxation of the internal anal sphincter to allow time for the fissure to heal, without permanent sphincter dysfunction, was greeted with enthusiasm and copious publication.

This evolution of medical therapy was summarized in another Cochrane review, including publications up to the end of 20029. It included studies in which participants were randomized to a non-surgical therapy for anal fissure. Comparison groups in each of these studies included an operative procedure, an alternate medical therapy, or placebo. Placebo therapy in most reports meant "best supportive care" applied sometimes equally to both groups, and sometimes only to the control group. In reports of chemical sphincterotomy this meant therapies tested earlier, such as bulk aperients, sitz baths and topical anesthetics.

Since 2002 many new studies have been published, making an update of the Cochrane review important. Work in this field has continued because too many problems remained with medical therapy as of 2003:

GTN ointment was hard to find.

It caused severe headache too often.

It only worked apparently about half the time.

There was great heterogeneity in the reported results, both clinical and statistical.

Quality of life studies show a great disparity between incontinence risk and patient satisfaction with sphincterotomy. How bad is the incontinence really?

Btx is very expensive and apparently no better than GTN, though again there is marked clinical heterogeneity in reported results.

CCBs held great promise, but topical therapy was impossible to find and data were sparse.

So have all these issues been addressed in more recent publication? Mostly no. Surgery has been shown in many new studies to still be far superior to any form of medical therapy in healing anal fissure10-16. Though GTN might be described as the “medical” gold standard, its results are at best mediocre and no new clinical trial is suddenly going to find a way to make it better. It has been copiously studied and new studies continue to be published17-19. It’s time to move on. And it still must be made up in a special pharmacy in most locations, making access to it a struggle for patients. The data for Btx and CCBs has filled out a bit and with no great revelations20.

What is interesting is the investigation of new and in some cases very novel approaches to medical therapy. These include substances such as indoramin, arginine, minoxidil and sildenafil21-27. None of these have jumped out as a clear equal to surgical sphincterotomy, but they demonstrate the breadth of possibilities that exist for further investigation for a surgical equivalent. This field has moved along very fast in the past 10 years and looks like there is much of great interest to come.

So what questions remain about medical therapy for anal fissure?

Why are placebo controlled trials of GTN still being done?

Why are we messing around with GTN ointment when two studies show that the GTN patch, used commonly for angina, is just as effective as GTN, universally available, cleaner and cheaper, and with equivalent morbidity28-29?

Is there more to be learned about the efficacy of Btx or CCBs20?

It is not certain whether fissure in children is exactly comparable to chronic fissure in adults, or that chronic spasm, hypertrophy and ischemia play a role in its persistence. For that reason surgery has rarely been applied to children with anal fissure and, until recently, laxatives and lubricants have formed the basis of therapy. The failure of these medications has led to the investigation of newer therapies in children.

Acute anal fissure in adults is thought to precede chronic fissure, to be more analogous to pediatric anal fissure in its pathologic anatomy and, if treated aggressively medically, might be healed preventing the development of chronic fissure.

And lastly, on a different point, I wish somebody would do another RCT comparing posterior midline to lateral internal sphincteromy.

REFERENCES

1 Goligher JC. Surgery of the anus, rectum & colon. 3rd ed. London. Balliere & Tindall. 1975.

2 Schouten WR, Briel JW, Auwerda JJ. Relationship between anal pressure and anodermal blood flow: the vascular pathogeneisis of anal fissure. Dis Colon Rectum. 1994;37:664-9.

3 Abcarian H. Surgical correction of chronic anal fissure: results of lateral internal sphincterotomy vs. fissurectomy-midline sphincterotomy. Dis Colon Rectum. 1980;23:31-6.

4 Garcia-Aguilar J, Belmonte C, Wong D, Lowry AC, Madoff RD. Open vs Closed sphincterotomy for chronic anal fissure: long term results. Dis Colon Rectum. 1996;39:440-3.

5 Nelson RL. Outcome of operative procedures for fissure in ano. Cochrane Library. 2003. #4

6 Rotholtz NA, Bun M, Mauri MV, Bosio R, Peczan CE, Mezzadri NA. Long term assessment of fecal incontinence after lateral internal sphincterotomy. Tech Coloproctology. 2005;9:115-8.

7 Hyman N. Incontinence after lateral internal sphincterotomy: a prospective study and quality of life assessment. Dis Colon Rectum. 2004 Jan;47(1):35-8.

8 Mentes BB, Tezcanes T, Yilmaz U, Leventoglu S,

Ogoz M. Resuts of lateral internal sohincterotomy for chronic anal fissure with particular reference to quality of life. Dis Colon Rectum. In press.

9 Nelson R. A systematic review of medical therapy for anal fissure. Diseases of the Colon & Rectum. 2004;47:422-31.

10 Mishra R, Thomas S, Maan MS, Hadke NS. Topical nitroglycerin versus lateral internal sphincterotomy for chronic anal fissure: prospective randomized trial. AND J Surg. 2005;75:1032-5

11 Parellada C. Randomized prospective trial comparing 0.2 percent isosorbide dinitrate ointment with sphincterotomy in treatment of chronic anal fissure: a two year follow-up. Dis. Colon Rectum. 2004;47:437-43.

12 Iswariah H, Stephens J, Rieger N, Rodda D, Hewett P. Randomized prospective controlled trial of lateral internal sphincterotomy versus injection of botulinum toxin for the treatment of idiopathic fissure in ano. ANZ J Surg. 2005;75:553-5

13 Massoud BW, Mehrdad V, Baharak T, Alireza Z. Botulinum toxin injection versus internal anal sphincterotomy for the treatment of chronic anal fissure. Ann Saud Med. 2005;25:140-2.

14 Arroyo A, Perez F, Serrano P, Candela F, Lacueva J, Calpena R. Surgical versus chemical (botulinum toxin) sphincterotomy for chronic anal fissure: long term results of a prospective randomized clinical and manometric study. Am J Surg. 2005;189:429-34.

15 Boschetto S, Giovannone M, Tosoni M, Barberani F. Hydropneumatic anal dilation in conservative treatment of chronic anal fissure: clinical outcomes and randomized comparison with topical nitroglycerin. Tech Coloproctol. 2004;8:89-92.

16 Ho KS, Ho YH. Randomized clinical trial comparing oral nifedipine with lateral sphincterotomy and tailored sphincterotomy in the treatment of chronic anal fissure. Br J Surg. 2005;92:403-8.