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Benign anal conditions: haemorrhoids, fissures, perianal abscess, fistula-in-ano and pilonidal sinus
INTESTINAL SURGERY II
Benign anal conditions: haemorrhoids, fissures, perianal abscess, fistula-in-ano and pilonidal sinus
First-degree haemorrhoids bleed, but do not prolapse. As the blood supply to the vascular cushions is arterial, bleeding tends to be bright red and occur after opening the bowels when the haemorrhoids are engorged. Bleeding often drips into the toilet bowl. Second-degree haemorrhoids prolapse and return spontaneously, third-degree need to be pushed back and fourth degree cannot be pushed back. The patient may describe ‘something down below’. Other symptoms include faecal/mucus discharge. This is often associated with prolapse and relates to the loss of efficiency of the ‘plug’ or ‘tap washer’ action of the haemorrhoids, which may result in chronic skin irritation. Pain is unusual but may relate to perianal irritation, thrombosis, or an alternative diagnosis such as a fissure. It is important to exclude a more sinister cause for these symptoms. If there are any risk factors in the history, if the patient has a family history of bowel cancer or is over 40 years of age, proximal luminal investigation for cancer is warranted. Examination with a proctoscope allows easy diagnosis of haemorrhoids as well as permitting out-patient therapy.
James P Tiernan Steven R Brown
Abstract Benign perianal conditions represent a significant workload for the general surgeon and colorectal specialist. Patients present with a variety of symptoms, some of which may be difficult to distinguish from a more sinister cause without a careful history, examination and investigation. This article discusses the basic aetiology, clinical features and current evidence-based treatment recommendations for each of the conditions of haemorrhoids, fissures, perianal abscess, fistula-in-ano and pilonidal sinus. (Ischiorectal abscess is not addressed.)
Treatment Over-the-counter medications may bring symptomatic relief for acute symptoms, but do not cure the underlying abnormality and may exacerbate chronic skin damage. There is randomized controlled trial (RCT) evidence that fibre supplements will improve symptoms in patients with first-degree piles. After exclusion of a more proximal cause if appropriate, fibre supplements combined with reassurance and improved lifestyle measures (avoiding straining, balanced diet, plenty of fluids) is often all that is required. Although not often prescribed in this country, the use of microionized flavinoids (Daflon) have also been shown to improve symptoms. Intervention is usually required for the successful treatment of prolapse. This can be carried out in clinic by attempting to ‘fix’ the haemorrhoid using either injection sclerotherapy (causing sclerosis by injecting oily phenol above the pile) or rubber band ligation (firing a rubber band around the mucosa just above the pile). Both techniques have relatively high recurrence rates. About 5% of patients undergoing ligation will have pain and/or vaso-vagal symptoms, particularly if the band is placed too low so it impinges on the sensitive dentate line. About 15% of patients will not respond at all and require surgical intervention. Thrombosed piles often present as an emergency. They should be distinguished from a perianal haematoma (often single and not extending into the anal canal) which may be treated early (<48 hours) with simple evacuation under local anaesthetic. Thrombosed piles may be treated conservatively with ice and analgesia. Hyaluronidase and local anaesthetic often resolve oedema and pain. Surgery is rarely indicated but if it is, excision of the largest area of thrombosis is often safe and effective. A summary of treatments for haemorrhoids is shown in Table 1.
Keywords Benign anal; fissure; fistula; haemorrhoids; perianal; piles; pilonidal
Haemorrhoids Definition, epidemiology and aetiology Haemorrhoids are vascular cushions of the anal canal (often called ‘piles’). These are physiological structures involved in the fine tuning of anal continence (acting like a plug or washer on a tap) and aiding defaecation (contraction of the fibro-elastic support to the cushions ‘squeezes out’ the blood and shrinks the haemorrhoid, increasing the anal lumen). Symptoms of haemorrhoids probably occur because of disruption of the supporting fibro-elastic scaffold leading to prolapse, poor vascular drainage and subsequent engorgement. Symptomatic haemorrhoids are common. Prevalence is difficult to estimate, but may be as high as one-third of the population; patients with haemorrhoidal symptoms make up about one in five referrals to the average colorectal specialist clinic. History and examination Haemorrhoids may be classified according to Goligher’s classification,1 although this does not necessarily define severity.
Surgery For over 70 years the standard surgical procedure for haemorrhoids was excision followed by leaving the anoderm open to heal by secondary intention (Milligan-Morgan technique) or closure (Ferguson technique). Both procedures require good mucosal bridges to avoid later stenosis. Unfortunately both result in significant pain and prolonged recovery. Improvements in pre-
James P Tiernan MRCS is a Research Fellow at St James’s Hospital, Leeds, UK. Conflict of interests: none declared. Steven R Brown MD FRCS is a Consultant Colorectal Surgeon at the Northern General Hospital, Sheffield, UK. Conflict of interests: none declared.
SURGERY 29:8
382
Ó 2011 Elsevier Ltd. All rights reserved.
INTESTINAL SURGERY II
a split in the distal anal mucosa resulting in characteristic sharp anal pain on defaecation and bleeding (Figure 1). Although often ascribed to constipation, less than 25% of patients are actually constipated. Instead studies have suggested the fissure is a form of ischaemic ulcer as a result of anal spasm and poor blood supply, particularly in the posterior midline of the anal canal.
Summary of therapy for haemorrhoids Degree of piles
Treatment
First degree
Reassure Diet and lifestyle changes Fibre supplements Microionized flavinoids (e.g. Daflon) Rubber band ligation (RBL)/Injection sclerotherapy Rubber band ligation (RBL) Surgery for failures e open haemorrhoidectomy e stapled haemorrhoidopexy e Doppler ligation (HAL) Open haemorrhoidectomy
Second and third degree
Fourth degree
History and examination Patients experience severe sharp pain (‘passing broken glass’) which may continue for two or more hours after defaecation. Bleeding appears as streaks on the toilet paper on wiping. Examination may reveal the ulcer (usually in the posterior midline), anal spasm and an anal skin tag or sentinel pile (an indication of chronicity). Occasionally the fissure is in the anterior midline. Any other position or multiple fissures should alert the surgeon to an alternative cause such as inflammatory bowel disease (Crohn’s disease). A full digital rectal examination should not be carried out to prevent exacerbation of pain, but further investigation to exclude a more proximal sinister cause should be considered after treatment.
Table 1
and aftercare (preoperative laxatives, diathermy or Ligasure excision, postoperative analgesia, metronidazole and glyceryl trinitrate (GTN)) have reduced this but it still remains a problem. Newer techniques strive to avoid cutting the anoderm. The stapled anopexy technique (PPH) utilizes a circular stapler to remove a doughnut of rectal mucosa above the haemorrhoids (hence reducing the vascular supply) and hitch up the piles. Advocates argue this is a more physiological procedure as the haemorrhoids are replaced in their anatomical position rather than being excised. There is less pain and more rapid recovery, but there may be a slightly higher recurrence rate, and the occasional serious complication. A newer method is detection of the haemorrhoidal blood supply and ligation using a modified proctoscope with a Doppler probe. The procedure may be combined with a ‘pexy’ suture (where the mucosa is ‘hitched up’ to reduce prolapsed). The operation is minimally invasive, has a rapid recovery time and seems to have a reasonably low recurrence rate, but further data are awaited.
Treatment First-line treatment includes lifestyle and dietary advice combined with simple oral and topical analgesia and mild laxatives if constipated. This is adequate to resolve most acute fissures. Non-surgical therapy for chronic fissures includes topical nitrates (e.g. GTN) and calcium channel blockers (e.g. diltiazem). These act to reduce sphincter tone and are said to improve blood supply to the ischaemic ulcer. They relieve pain and may heal fissures after a prolonged (6e8 week) course. Persistent or recurrent fissures may respond to alternative topical therapy; botulinum toxin (Botox) has also been shown to heal fissures when injected into the region of the fissure, and may be even more effective if combined with a fissurectomy to ‘freshen the edges’ and promote healing. Surgery Although non-surgical options for treatment have gained popularity recently, surgery remains common as no available medical therapy has been proven to be more effective. Surgical intervention again aims to reduce sphincter tone by partial cutting of the internal sphincter (sphincterotomy). This is an extremely effective method
Anal fissure Definition, epidemiology and aetiology Anal fissure is one of the most common causes of anal pain, occurring most frequently in 20e40-year olds (but also in young children), with an equal sex distribution. It is characterized by
Options for treatment of anal fissure Fissure treatment options
Details
Conservative therapy
High-fibre diet Oral fluids Stool softeners Analgesia (oral and topical) GTN ointment (0.2e0.4%) [headache risk] Diltiazem gel (2%) Lateral sphincterotomy Botulinum toxin injection Fissurectomy Advancement flap
Medical therapy
Surgical therapy
Figure 1 Proctoscopy showing chronic anal fissure.
SURGERY 29:8
Table 2
383
Ó 2011 Elsevier Ltd. All rights reserved.
INTESTINAL SURGERY II
of treating fissures with a success rate of over 90%. One drawback is the potential for sphincter compromise and passive incontinence, especially for flatus. This complication may be limited by carrying out a lateral sphincterotomy rather than posteriorly through the fissure (which may result in a ‘keyhole defect’), reducing the length of cut sphincter to the length of the fissure (‘tailored sphincterotomy’) and applying caution in high-risk groups (particularly women who have a shorter anal canal) and patients with a fissure but little spasm. An alternative to sphincterotomy, particularly in the high-risk groups, is an anal advancement flap. Although there is a higher recurrence rate with this procedure, there is a very low risk of incontinence. Treatment options for anal fissure are summarized in Table 2.
drain into the anal crypts at the level of the dentate line. Park’s cryptoglandular theory2 proposes that it is blockage of these glands that results in the abscess. Anorectal abscesses are classified according to their location in one of several potential anorectal spaces, with perianal abscesses (the commonest) occurring in the area around the anal verge. (Ischiorectal abscess will not be discussed in this article.) History and examination The hallmarks of a perianal abscess include pain, swelling and fever. Inspection will reveal erythema, swelling and possible fluctuance. Deeper abscesses may have no visible external manifestations. Digital rectal examination is often not possible due to severe pain and tenderness. Treatment The treatment of a perianal abscess is incision and drainage. There is little justification for a ‘watch and wait’ policy with antibiotics which may allow the suppurative process to progress to a more complex abscess, possible injury to the sphincter and
Perianal abscess Definition, epidemiology and aetiology Ninety percent of all anorectal abscesses result from an infection of the anal glands that are interspersed around the anal canal and
Parks’ classification of fistula-in-ano Type I
Type II
45%
30%
LA PR EAS
IAS
Dentate line Type III
Type IV
20%
5%
Figure 2 Type I, intersphincteric; type II, trans-sphincteric; type III, suprasphincteric, type IV, extrasphincteric. The terms ‘trans-’, ‘supra-’ and ‘extra-’ refer to the external sphincter mass. EAS, external anal sphincter; IAS, internal anal sphincter; LA, levator ani; PR, puborectalis.
SURGERY 29:8
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Ó 2011 Elsevier Ltd. All rights reserved.
INTESTINAL SURGERY II
in some cases (particularly diabetics and the immunocompromised) life-threatening sepsis. The most fluctuant point of the abscess should be located either under local or general anaesthetic and a cruciate incision made. The edges are excised to prevent the skin closing prematurely over the top of the cavity resulting in poor drainage and recurrence, and the cavity should be cleaned with breakdown of any loculations. Packing is not usually required provided there is adequate deroofing.
formation. It allows easy identification of the tract and assessment of muscle involvement in the conscious patient, and further surgical intervention can be undertaken at a later date. In some cases (particularly Crohn’s) the loose seton can be left as a long-term solution. If placed tightly (a cutting seton), it can slowly cut through the sphincter allowing the tract to become more superficial and therefore representing definitive treatment. For patients with a (rare) high fistula where the lay-open technique is not appropriate or the seton is not tolerated, other options include the advancement flap. In combination with coring out the tract, the internal opening is covered with either rectal mucosa advanced distally (endorectal advancement flap) or perianal skin advanced proximally (ano-cutaneous advancement flap). Other options for treatment include fibrin glue and fistula plugs (see Table 3).
Fistula-in-ano Definition, epidemiology and aetiology A fistula-in-ano is an abnormal track or cavity communicating with the rectum or anal canal by an identifiable internal opening. The fistula is the continuum of the spectrum of disease described as cryptoglandular in the previous section. Persistence of the anal gland in part of the tract between the crypt and the blocked part of the duct results in fistula formation.
Pilonidal sinus Definition, epidemiology and aetiology A pilonidal sinus is literally a nest of hairs. Classically it occurs in the natal cleft but can also occur in the umbilicus or the hand webspaces of hairdressers. The aetiology is poorly understood. Current theories suggest the repeated rubbing action of skin causes pit formation by driving the hairs into the skin. Patients may perhaps outgrow the tendency to form these sinuses as they are rarely seen in those over 40 years of age.
Classification Parks’ classification of fistula-in-ano2 is the commonest classification and its use is particularly applicable to the treatment options (Figure 2). History and examination Patients often report a previous abscess that was surgically drained or spontaneously burst. Subsequent persistent discharge, pain and bleeding may occur, often in a cyclical fashion. Additional bowel symptoms may be present when the fistula is secondary to inflammatory bowel disease, or other secondary causes. Examination usually reveals an external opening which may discharge pus on gentle massage. A lubricated finger should feel for the tract which can be palpated as a cord-like structure. On digital rectal examination the internal opening may be felt as a nodule and the tissue on either side of the anal canal and rectum should be compared. Asymmetrical differences in tissue consistency may indicate supralevator extensions. Rigid sigmoidoscopy should be undertaken to exclude underlying pathology. Goodsall’s rule3 states that an external opening seen posterior to a line drawn transversely across the perineum will originate from an internal opening in the posterior midline, whereas an external opening anterior to this line will originate from the nearest crypt. There are exceptions to this rule, especially in Crohn’s disease.
History and examination Patients often present acutely with an abscess in or close to the natal cleft. Those who present electively often have a history of repeated abscess formation and discharge, or surgical drainage. On parting the buttocks one or more midline pits will be seen, occasionally with protruding hairs. Care should be taken to
Options for treatment of fistula-in-ano
Treatment The aims are to eliminate the fistula, prevent recurrence and preserve sphincter function. A careful assessment of the complexity of the fistula should be undertaken. This may require an MRI scan in order to provide a road map of the tract(s). Even if imaging is available, a careful examination should be carried out under anaesthetic with the gentle use of probes with or without methylene blue and/or hydrogen peroxide to identify the fistula. The majority of fistulae are low, involving little muscle, enabling the lay-open technique to be used. If the fistula involves more muscle this technique may compromise sphincter function resulting in incontinence and a seton (foreign material such as thread, wire or silastic passed through a fistula, encircling the sphincter muscle, to aid drainage) may be utilized instead. If placed loosely this has the advantage of draining the tract and avoiding abscess
SURGERY 29:8
Options for treatment of a fistula-in-ano
Examples of fistula indications
Lay open
Simple low fistula Intersphincteric Low trans-sphincteric High trans-sphincteric Low anterior trans-sphincteric Crohn’s Intermediate and high trans-sphincteric High trans-sphincteric After loose seton (two stages) Crohn’s Post-seton insertion e secondary tracts identified and treated e no residual sepsis e long tract Controversial, probably does not work
Loose seton
Cutting seton Advancement flap
Fistula plug
Fibrin glue
Table 3
385
Ó 2011 Elsevier Ltd. All rights reserved.
INTESTINAL SURGERY II
tions have been described and can be divided into those in which the wound is left open and those where it is closed. Operations can also be midline or asymmetric. Although it is difficult to ascertain precisely from the literature which procedure is best in terms of success and morbidity, current thinking favours the asymmetric techniques as these are less likely to result in an unhealed midline wound. Amongst these operations, the Bascom’s procedure has the advantage of being an ambulatory local anaesthetic procedure that gives good results, but with the disadvantage of an open wound. Conversely rotation flaps require more significant surgery and are cosmetically disfiguring. They should probably be reserved for those with recurrent disease after less invasive options have failed. Secondary procedures by the plastic surgeon once sepsis has been eliminated have their place in recurrent disease. Surgical choices are summarized in Table 4. A
Options for surgical treatment of a pilonidal sinus
Open
Closed
Midline
Asymmetric
Simple lay open Wide excision with marsupialization Wide excision with primary closure
Bascom’s procedure
Bascom’s cleft closure Karydakis’ operation Rotational flaps
Table 4
identify all pits which may be some distance from the discharging sinus as recurrence due to missed pits is common. Treatment Although conservative options do exist (mainly repeated depilation), most patients undergo surgical intervention either acutely in the form of incision and drainage of an abscess or electively.
REFERENCES 1 Goligher JC. Haemorrhoids or piles. In: Surgery of the anus, rectum and colon. 5th edn. London: Bailliere Tindall, 1984. 2 Parks AG, Gordon PH, Hardcastle JD. A classification of fistula-in-ano. Br J Surg 1976; 63: 1e12. 3 Goodsall DH, Miles WE. Anorectal fistula. Dis Colon Rectum 1982; 25: 262e78.
Surgery The perfect operation for pilonidal disease would have a high success rate with minimal morbidity. The most problematic morbidity is a persistent unhealed midline wound. Many opera-
SURGERY 29:8
386
Ó 2011 Elsevier Ltd. All rights reserved.
Benign anal conditions: haemorrhoids, fissures, perianal abscess, fistula-in-ano and pilonidal sinus
First-degree haemorrhoids bleed, but do not prolapse. As the blood supply to the vascular cushions is arterial, bleeding tends to be bright red and occur after opening the bowels when the haemorrhoids are engorged. Bleeding often drips into the toilet bowl. Second-degree haemorrhoids prolapse and return spontaneously, third-degree need to be pushed back and fourth degree cannot be pushed back. The patient may describe ‘something down below’. Other symptoms include faecal/mucus discharge. This is often associated with prolapse and relates to the loss of efficiency of the ‘plug’ or ‘tap washer’ action of the haemorrhoids, which may result in chronic skin irritation. Pain is unusual but may relate to perianal irritation, thrombosis, or an alternative diagnosis such as a fissure. It is important to exclude a more sinister cause for these symptoms. If there are any risk factors in the history, if the patient has a family history of bowel cancer or is over 40 years of age, proximal luminal investigation for cancer is warranted. Examination with a proctoscope allows easy diagnosis of haemorrhoids as well as permitting out-patient therapy.
James P Tiernan Steven R Brown
Abstract Benign perianal conditions represent a significant workload for the general surgeon and colorectal specialist. Patients present with a variety of symptoms, some of which may be difficult to distinguish from a more sinister cause without a careful history, examination and investigation. This article discusses the basic aetiology, clinical features and current evidence-based treatment recommendations for each of the conditions of haemorrhoids, fissures, perianal abscess, fistula-in-ano and pilonidal sinus. (Ischiorectal abscess is not addressed.)
Treatment Over-the-counter medications may bring symptomatic relief for acute symptoms, but do not cure the underlying abnormality and may exacerbate chronic skin damage. There is randomized controlled trial (RCT) evidence that fibre supplements will improve symptoms in patients with first-degree piles. After exclusion of a more proximal cause if appropriate, fibre supplements combined with reassurance and improved lifestyle measures (avoiding straining, balanced diet, plenty of fluids) is often all that is required. Although not often prescribed in this country, the use of microionized flavinoids (Daflon) have also been shown to improve symptoms. Intervention is usually required for the successful treatment of prolapse. This can be carried out in clinic by attempting to ‘fix’ the haemorrhoid using either injection sclerotherapy (causing sclerosis by injecting oily phenol above the pile) or rubber band ligation (firing a rubber band around the mucosa just above the pile). Both techniques have relatively high recurrence rates. About 5% of patients undergoing ligation will have pain and/or vaso-vagal symptoms, particularly if the band is placed too low so it impinges on the sensitive dentate line. About 15% of patients will not respond at all and require surgical intervention. Thrombosed piles often present as an emergency. They should be distinguished from a perianal haematoma (often single and not extending into the anal canal) which may be treated early (<48 hours) with simple evacuation under local anaesthetic. Thrombosed piles may be treated conservatively with ice and analgesia. Hyaluronidase and local anaesthetic often resolve oedema and pain. Surgery is rarely indicated but if it is, excision of the largest area of thrombosis is often safe and effective. A summary of treatments for haemorrhoids is shown in Table 1.
Keywords Benign anal; fissure; fistula; haemorrhoids; perianal; piles; pilonidal
Haemorrhoids Definition, epidemiology and aetiology Haemorrhoids are vascular cushions of the anal canal (often called ‘piles’). These are physiological structures involved in the fine tuning of anal continence (acting like a plug or washer on a tap) and aiding defaecation (contraction of the fibro-elastic support to the cushions ‘squeezes out’ the blood and shrinks the haemorrhoid, increasing the anal lumen). Symptoms of haemorrhoids probably occur because of disruption of the supporting fibro-elastic scaffold leading to prolapse, poor vascular drainage and subsequent engorgement. Symptomatic haemorrhoids are common. Prevalence is difficult to estimate, but may be as high as one-third of the population; patients with haemorrhoidal symptoms make up about one in five referrals to the average colorectal specialist clinic. History and examination Haemorrhoids may be classified according to Goligher’s classification,1 although this does not necessarily define severity.
Surgery For over 70 years the standard surgical procedure for haemorrhoids was excision followed by leaving the anoderm open to heal by secondary intention (Milligan-Morgan technique) or closure (Ferguson technique). Both procedures require good mucosal bridges to avoid later stenosis. Unfortunately both result in significant pain and prolonged recovery. Improvements in pre-
James P Tiernan MRCS is a Research Fellow at St James’s Hospital, Leeds, UK. Conflict of interests: none declared. Steven R Brown MD FRCS is a Consultant Colorectal Surgeon at the Northern General Hospital, Sheffield, UK. Conflict of interests: none declared.
SURGERY 29:8
382
Ó 2011 Elsevier Ltd. All rights reserved.
INTESTINAL SURGERY II
a split in the distal anal mucosa resulting in characteristic sharp anal pain on defaecation and bleeding (Figure 1). Although often ascribed to constipation, less than 25% of patients are actually constipated. Instead studies have suggested the fissure is a form of ischaemic ulcer as a result of anal spasm and poor blood supply, particularly in the posterior midline of the anal canal.
Summary of therapy for haemorrhoids Degree of piles
Treatment
First degree
Reassure Diet and lifestyle changes Fibre supplements Microionized flavinoids (e.g. Daflon) Rubber band ligation (RBL)/Injection sclerotherapy Rubber band ligation (RBL) Surgery for failures e open haemorrhoidectomy e stapled haemorrhoidopexy e Doppler ligation (HAL) Open haemorrhoidectomy
Second and third degree
Fourth degree
History and examination Patients experience severe sharp pain (‘passing broken glass’) which may continue for two or more hours after defaecation. Bleeding appears as streaks on the toilet paper on wiping. Examination may reveal the ulcer (usually in the posterior midline), anal spasm and an anal skin tag or sentinel pile (an indication of chronicity). Occasionally the fissure is in the anterior midline. Any other position or multiple fissures should alert the surgeon to an alternative cause such as inflammatory bowel disease (Crohn’s disease). A full digital rectal examination should not be carried out to prevent exacerbation of pain, but further investigation to exclude a more proximal sinister cause should be considered after treatment.
Table 1
and aftercare (preoperative laxatives, diathermy or Ligasure excision, postoperative analgesia, metronidazole and glyceryl trinitrate (GTN)) have reduced this but it still remains a problem. Newer techniques strive to avoid cutting the anoderm. The stapled anopexy technique (PPH) utilizes a circular stapler to remove a doughnut of rectal mucosa above the haemorrhoids (hence reducing the vascular supply) and hitch up the piles. Advocates argue this is a more physiological procedure as the haemorrhoids are replaced in their anatomical position rather than being excised. There is less pain and more rapid recovery, but there may be a slightly higher recurrence rate, and the occasional serious complication. A newer method is detection of the haemorrhoidal blood supply and ligation using a modified proctoscope with a Doppler probe. The procedure may be combined with a ‘pexy’ suture (where the mucosa is ‘hitched up’ to reduce prolapsed). The operation is minimally invasive, has a rapid recovery time and seems to have a reasonably low recurrence rate, but further data are awaited.
Treatment First-line treatment includes lifestyle and dietary advice combined with simple oral and topical analgesia and mild laxatives if constipated. This is adequate to resolve most acute fissures. Non-surgical therapy for chronic fissures includes topical nitrates (e.g. GTN) and calcium channel blockers (e.g. diltiazem). These act to reduce sphincter tone and are said to improve blood supply to the ischaemic ulcer. They relieve pain and may heal fissures after a prolonged (6e8 week) course. Persistent or recurrent fissures may respond to alternative topical therapy; botulinum toxin (Botox) has also been shown to heal fissures when injected into the region of the fissure, and may be even more effective if combined with a fissurectomy to ‘freshen the edges’ and promote healing. Surgery Although non-surgical options for treatment have gained popularity recently, surgery remains common as no available medical therapy has been proven to be more effective. Surgical intervention again aims to reduce sphincter tone by partial cutting of the internal sphincter (sphincterotomy). This is an extremely effective method
Anal fissure Definition, epidemiology and aetiology Anal fissure is one of the most common causes of anal pain, occurring most frequently in 20e40-year olds (but also in young children), with an equal sex distribution. It is characterized by
Options for treatment of anal fissure Fissure treatment options
Details
Conservative therapy
High-fibre diet Oral fluids Stool softeners Analgesia (oral and topical) GTN ointment (0.2e0.4%) [headache risk] Diltiazem gel (2%) Lateral sphincterotomy Botulinum toxin injection Fissurectomy Advancement flap
Medical therapy
Surgical therapy
Figure 1 Proctoscopy showing chronic anal fissure.
SURGERY 29:8
Table 2
383
Ó 2011 Elsevier Ltd. All rights reserved.
INTESTINAL SURGERY II
of treating fissures with a success rate of over 90%. One drawback is the potential for sphincter compromise and passive incontinence, especially for flatus. This complication may be limited by carrying out a lateral sphincterotomy rather than posteriorly through the fissure (which may result in a ‘keyhole defect’), reducing the length of cut sphincter to the length of the fissure (‘tailored sphincterotomy’) and applying caution in high-risk groups (particularly women who have a shorter anal canal) and patients with a fissure but little spasm. An alternative to sphincterotomy, particularly in the high-risk groups, is an anal advancement flap. Although there is a higher recurrence rate with this procedure, there is a very low risk of incontinence. Treatment options for anal fissure are summarized in Table 2.
drain into the anal crypts at the level of the dentate line. Park’s cryptoglandular theory2 proposes that it is blockage of these glands that results in the abscess. Anorectal abscesses are classified according to their location in one of several potential anorectal spaces, with perianal abscesses (the commonest) occurring in the area around the anal verge. (Ischiorectal abscess will not be discussed in this article.) History and examination The hallmarks of a perianal abscess include pain, swelling and fever. Inspection will reveal erythema, swelling and possible fluctuance. Deeper abscesses may have no visible external manifestations. Digital rectal examination is often not possible due to severe pain and tenderness. Treatment The treatment of a perianal abscess is incision and drainage. There is little justification for a ‘watch and wait’ policy with antibiotics which may allow the suppurative process to progress to a more complex abscess, possible injury to the sphincter and
Perianal abscess Definition, epidemiology and aetiology Ninety percent of all anorectal abscesses result from an infection of the anal glands that are interspersed around the anal canal and
Parks’ classification of fistula-in-ano Type I
Type II
45%
30%
LA PR EAS
IAS
Dentate line Type III
Type IV
20%
5%
Figure 2 Type I, intersphincteric; type II, trans-sphincteric; type III, suprasphincteric, type IV, extrasphincteric. The terms ‘trans-’, ‘supra-’ and ‘extra-’ refer to the external sphincter mass. EAS, external anal sphincter; IAS, internal anal sphincter; LA, levator ani; PR, puborectalis.
SURGERY 29:8
384
Ó 2011 Elsevier Ltd. All rights reserved.
INTESTINAL SURGERY II
in some cases (particularly diabetics and the immunocompromised) life-threatening sepsis. The most fluctuant point of the abscess should be located either under local or general anaesthetic and a cruciate incision made. The edges are excised to prevent the skin closing prematurely over the top of the cavity resulting in poor drainage and recurrence, and the cavity should be cleaned with breakdown of any loculations. Packing is not usually required provided there is adequate deroofing.
formation. It allows easy identification of the tract and assessment of muscle involvement in the conscious patient, and further surgical intervention can be undertaken at a later date. In some cases (particularly Crohn’s) the loose seton can be left as a long-term solution. If placed tightly (a cutting seton), it can slowly cut through the sphincter allowing the tract to become more superficial and therefore representing definitive treatment. For patients with a (rare) high fistula where the lay-open technique is not appropriate or the seton is not tolerated, other options include the advancement flap. In combination with coring out the tract, the internal opening is covered with either rectal mucosa advanced distally (endorectal advancement flap) or perianal skin advanced proximally (ano-cutaneous advancement flap). Other options for treatment include fibrin glue and fistula plugs (see Table 3).
Fistula-in-ano Definition, epidemiology and aetiology A fistula-in-ano is an abnormal track or cavity communicating with the rectum or anal canal by an identifiable internal opening. The fistula is the continuum of the spectrum of disease described as cryptoglandular in the previous section. Persistence of the anal gland in part of the tract between the crypt and the blocked part of the duct results in fistula formation.
Pilonidal sinus Definition, epidemiology and aetiology A pilonidal sinus is literally a nest of hairs. Classically it occurs in the natal cleft but can also occur in the umbilicus or the hand webspaces of hairdressers. The aetiology is poorly understood. Current theories suggest the repeated rubbing action of skin causes pit formation by driving the hairs into the skin. Patients may perhaps outgrow the tendency to form these sinuses as they are rarely seen in those over 40 years of age.
Classification Parks’ classification of fistula-in-ano2 is the commonest classification and its use is particularly applicable to the treatment options (Figure 2). History and examination Patients often report a previous abscess that was surgically drained or spontaneously burst. Subsequent persistent discharge, pain and bleeding may occur, often in a cyclical fashion. Additional bowel symptoms may be present when the fistula is secondary to inflammatory bowel disease, or other secondary causes. Examination usually reveals an external opening which may discharge pus on gentle massage. A lubricated finger should feel for the tract which can be palpated as a cord-like structure. On digital rectal examination the internal opening may be felt as a nodule and the tissue on either side of the anal canal and rectum should be compared. Asymmetrical differences in tissue consistency may indicate supralevator extensions. Rigid sigmoidoscopy should be undertaken to exclude underlying pathology. Goodsall’s rule3 states that an external opening seen posterior to a line drawn transversely across the perineum will originate from an internal opening in the posterior midline, whereas an external opening anterior to this line will originate from the nearest crypt. There are exceptions to this rule, especially in Crohn’s disease.
History and examination Patients often present acutely with an abscess in or close to the natal cleft. Those who present electively often have a history of repeated abscess formation and discharge, or surgical drainage. On parting the buttocks one or more midline pits will be seen, occasionally with protruding hairs. Care should be taken to
Options for treatment of fistula-in-ano
Treatment The aims are to eliminate the fistula, prevent recurrence and preserve sphincter function. A careful assessment of the complexity of the fistula should be undertaken. This may require an MRI scan in order to provide a road map of the tract(s). Even if imaging is available, a careful examination should be carried out under anaesthetic with the gentle use of probes with or without methylene blue and/or hydrogen peroxide to identify the fistula. The majority of fistulae are low, involving little muscle, enabling the lay-open technique to be used. If the fistula involves more muscle this technique may compromise sphincter function resulting in incontinence and a seton (foreign material such as thread, wire or silastic passed through a fistula, encircling the sphincter muscle, to aid drainage) may be utilized instead. If placed loosely this has the advantage of draining the tract and avoiding abscess
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Options for treatment of a fistula-in-ano
Examples of fistula indications
Lay open
Simple low fistula Intersphincteric Low trans-sphincteric High trans-sphincteric Low anterior trans-sphincteric Crohn’s Intermediate and high trans-sphincteric High trans-sphincteric After loose seton (two stages) Crohn’s Post-seton insertion e secondary tracts identified and treated e no residual sepsis e long tract Controversial, probably does not work
Loose seton
Cutting seton Advancement flap
Fistula plug
Fibrin glue
Table 3
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INTESTINAL SURGERY II
tions have been described and can be divided into those in which the wound is left open and those where it is closed. Operations can also be midline or asymmetric. Although it is difficult to ascertain precisely from the literature which procedure is best in terms of success and morbidity, current thinking favours the asymmetric techniques as these are less likely to result in an unhealed midline wound. Amongst these operations, the Bascom’s procedure has the advantage of being an ambulatory local anaesthetic procedure that gives good results, but with the disadvantage of an open wound. Conversely rotation flaps require more significant surgery and are cosmetically disfiguring. They should probably be reserved for those with recurrent disease after less invasive options have failed. Secondary procedures by the plastic surgeon once sepsis has been eliminated have their place in recurrent disease. Surgical choices are summarized in Table 4. A
Options for surgical treatment of a pilonidal sinus
Open
Closed
Midline
Asymmetric
Simple lay open Wide excision with marsupialization Wide excision with primary closure
Bascom’s procedure
Bascom’s cleft closure Karydakis’ operation Rotational flaps
Table 4
identify all pits which may be some distance from the discharging sinus as recurrence due to missed pits is common. Treatment Although conservative options do exist (mainly repeated depilation), most patients undergo surgical intervention either acutely in the form of incision and drainage of an abscess or electively.
REFERENCES 1 Goligher JC. Haemorrhoids or piles. In: Surgery of the anus, rectum and colon. 5th edn. London: Bailliere Tindall, 1984. 2 Parks AG, Gordon PH, Hardcastle JD. A classification of fistula-in-ano. Br J Surg 1976; 63: 1e12. 3 Goodsall DH, Miles WE. Anorectal fistula. Dis Colon Rectum 1982; 25: 262e78.
Surgery The perfect operation for pilonidal disease would have a high success rate with minimal morbidity. The most problematic morbidity is a persistent unhealed midline wound. Many opera-
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