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Minor anorectal conditions
Haemorrhoids
Anatomy and physiology
Haemorrhoids are vascular arteriovenous plexuses that form two sets of anal cushions in the normal rectal anatomy. These plexuses are located in the upper anal canal above the dentate line (internal haemorrhoidal plexus), and at the anal verge (external haemorrhoidal plexus). The internal haemorrhoidal plexus or internal haemorrhoids, also known as anal cushions , lie above the dentate line and are covered by columnar epithelial cells that have visceral innervations. Anal cushions or internal haemorrhoids are classically described as being in the right anterior, right posterior and left lateral aspect of the anal canal (‘4-7-11 o’clock’ in the lithotomy position). , Newer technologies investigating the rectal and anal canal vasculature as a potential target for the treatment of haemorrhoidal disease have established an average of six haemorrhoidal arteries originating from the superior rectal artery and reaching the haemorrhoidal zone (range 1–8). The internal haemorrhoidal plexus drains via the middle rectal veins into the internal iliac vessels. The internal haemorrhoids complement anal sphincter function in normal physiology by providing fine control over the continence of liquid and gas, however, their abnormal enlargement produces haemorrhoidal disease, corresponding to the common complaints experienced by patients and treated by colorectal surgeons. It has been demonstrated that the anal cushions can contribute to up 20% of the resting anal pressure. The external haemorrhoidal plexus also known as external haemorrhoids , lie below the dentate line in the subcutaneous tissue at the anal verge and drain via the inferior rectal veins into the pudendal vessels and then into the internal iliac vein. These haemorrhoids are not normally visible and do not really contribute to the physiology of the anal canal. These vessels are covered by anoderm that is comprised of modified squamous epithelium containing pain fibres, thus affecting the way they present and are treated.
The words ‘haemorrhoids’ and ‘haemorrhoidal disease’ are not synonymous and should be used specifically to name either the presence of normal arteriovenous plexuses or the disease produced by their engorgement, respectively.
Aetiology and pathogenesis
Haemorrhoidal disease affecting the internal haemorrhoids develops when tissues supporting the anal cushions deteriorate and allow them to slide down into the anal canal, which in turn leads to impaired venous drainage, progressive venous engorgement, local stasis and transudation of fluid. The anal cushions function normally when they are fixed to their proper sites within the anal canal by fibromuscular ligaments, which are the anal remnants of the longitudinal layer of the muscularis propria from the rectum (Treitz’s ligaments). When these submucosal fibres fragment, the anal cushions are no longer restrained from engorging excessively with blood and may result in bleeding and prolapse. These fibres may be fragmented by prolonged and repeated downward stress related to straining during defaecation. Veins that traverse the anal sphincter are blocked whereas arterial inflow continues, leading to increasing haemorrhoidal congestion. Once prolapse occurs, further engorgement of these vascular cushions leads to pain, and anal spasm then prevents reduction, leading to a vicious cycle of prolapse and congestion of the vascular cushions. Risk factors for this condition are those, which directly or indirectly are associated with excessive straining and/or increased intra-abdominal pressures (i.e., constipation, hard stools, pregnancy). The progressive descent of the internal cushions produces various degrees of prolapse (see later), one the main symptoms of haemorrhoidal disease, while external haemorrhoidal disease manifests directly with venous engorgement. Defaecation in the squatting position may also aggravate the tendency to prolapse as it increases perineal descent and pressure. The anatomical alterations modify the vascular haemodynamics by decreasing venous reflux (especially in the erect position) and increasing the intravascular venous pressure. Microtrauma elicited during defaecation of hard solid stools produces small lacerations of the vessel wall and, consequently, another important symptom – bleeding. The venous hypertension of the diseased anal cushions augments the filtration of fluid through the vessel wall (transudate) producing what has been referred to ‘soiling’ (although its pathogenesis is not because of anal incontinence) and local itching. Local blood stasis also promotes venous thrombosis, and the sudden onset of venous hypertension stretches the mucosa overlying the cushion and causes the typical severe perianal pain during the attack (thrombosed haemorrhoidal disease). The external haemorrhoidal plexus also known as external haemorrhoids , lie in the subcutaneous tissue at the anal verge, are not normally visible and only cause symptoms when acutely thrombosed causing localised swelling and severe acute pain.
Classification
The classic staging of haemorrhoidal disease refers to the internal plexus prolapse and is classified into four degrees (Goligher’s classification): grade 1 – the anal cushions bleed but do not prolapse; grade 2 – the anal cushions prolapse through the anus on straining but reduce spontaneously; grade 3 – the anal cushions prolapse through the anus on straining or exertion and require manual replacement into the anal canal; and grade 4 – the anal cushions are constantly prolapsed. This classification is therefore a clinical classification based on the actual symptoms rather than size or appearance of haemorrhoids.
Symptoms and diagnosis
The most frequent symptom of haemorrhoidal disease is bleeding, normally reported as bright red. Bleeding is usually self-limiting, although in patients on anticoagulation or with predisposing bleeding diathesis can be more abundant. Other symptoms include prolapse ( Fig. 17.1 ), mucous discharge, itching and feeling of a lump. Thrombosed haemorrhoid from the internal plexus normally presents as a very large and painful prolapsed pile. This non-reducible haemorrhoid should not be described as ‘external haemorrhoids’. Thrombosis of external haemorrhoids is also responsible for acute anal pain irrespective of bowel movements. In contrast to thrombosed haemorrhoids from the internal plexus, thrombosed haemorrhoids from the external plexus will present as a relatively small and well-defined nodule at the anal verge. This very painful condition is also known as perianal haematoma . External haemorrhoids should not be confused with anal skin tags that are always present and not normally painful.
Haemorrhoidal disease can be diagnosed by history, examination (including inspection of the anal canal). Fresh bleeding not associated with any other anal symptoms and without any other colorectal alarm symptoms (i.e., change in bowel habit, abdominal pain) or without family history of colorectal neoplasia should still be investigated with a flexible sigmoidoscopy. Positive faecal occult blood, anaemia or right-sided abdominal pain/palpable mass should be evaluated by a complete colonic examination (either a colonoscopy or computed tomography [CT] virtual colonography).
Management
Therapeutic strategies normally depend on the severity of symptoms and the amount of haemorrhoidal tissue prolapsing beyond the anal verge (Goligher classification; see Table 17.1 later).
Table 17.1
Level of evidence for the treatment of haemorrhoids according to the severity of prolapse
| Level of evidence | ||||
|---|---|---|---|---|
| I | II | III | IV | |
| First degree | Dietary changes and flavonoids | Rubber-band banding Sclerotherapy Infrared coagulation |
||
| Second degree | Rubber-band ligation | HAL ∗ /THD ∗∗ | Stapled haemorrhoidopexy | |
| Third degree | Stapled haemorrhoidopexy | Haemorrhoidectomy | HAL ∗ /THD ∗∗ Rubber band ligation |
|
| Fourth degree | Haemorrhoidectomy | Stapled haemorrhoidopexy, THD/HAL with haemorrhoidopexy |
||
| Single external cushion | Haemorrhoidectomy (Ultracision, Ligasure) | |||
First degree
Dietary changes
If the piles are not prolapsing, non-operative methods should be attempted first. The primary problems of constipation and straining at stool need to be addressed. In some patients, improving bowel action with laxatives in the form of fibres may help to control the symptoms, especially bleeding.
Phlebotonics
Phlebotonics consist of plant extracts (i.e., flavonoids) and synthetic compounds (i.e., calcium dobesilate), which improve venous tone, stabilise capillary permeability and increase lymphatic drainage. There are several available phlebotonics but Daflon 500® (Les Laboratoires Servier, France) is by far the best evaluated in the medical literature, and is widely used in Europe and the Far East. Its pharmacological properties include noradrenalin-mediated venous contraction, reduction in blood extravasation from capillaries and inhibition of prostaglandin (PGE 2 , PGF 2 )-mediated inflammatory response. Phlebotonics, although currently not available in the UK, improve pain, bleeding, leakage and pruritus in meta-analyses of randomised controlled trials (RCTs) , and have been introduced in national guidelines.
Other forms of treatment that can give more immediate symptomatic relief include rubber-band ligation (RBL), injection sclerotherapy, infrared coagulation. Only cases refractory to non-operative methods should undergo these more invasive treatments. , Topical applications are popular with many patients, who testify relief from bleeding and pain. There are, however, no clinical trials to demonstrate any benefit from such applications.
Dietary changes, fibres and phlebotonics help control symptoms in first degree haemorrhoidal disease. Invasive treatments should be reserved for refractory cases.
Second degree
Rubber-band ligation
RBL is the technique of choice for second-degree haemorrhoidal disease, , for which it is effective in 68% of patients at 5 years follow-up with a 2–5% risk of secondary haemorrhage. Rubber bands are applied in an outpatient clinic or at the end of an endoscopic examination, at the apex of the haemorrhoidal tissues just above the dentate line, taking care to avoid catching the dentate line. The strangulated tissue then becomes necrotic and sloughs off in a few days, after which the wound fibroses, resulting in fixation of the mucosa akin to forming new suspensory ligaments for the anal cushions. The haemorrhoidal tissue is thus prevented from engorging and prolapsing.
RBL is the treatment of choice for second-degree haemorrhoidal disease when compared with excisional haemorrhoidectomy. In this group, it achieved similar results without the side effects of surgery. Surgery should be reserved for recurrent or third-degree haemorrhoids.
Anal pain, although uncommon, is a well-known sequela of RBL, however, the procedure is relatively painless if correctly performed above the dentate line. The use of local anaesthetic infiltration before the RBL decreases the amount of post-procedure pain experienced. Bleeding can occur up to 14 days after the ligation and can be important especially on patients receiving anticoagulants, therefore RBL should be used with caution in these cases and following careful discussion about the necessity to suspend anticoagulants for 2 weeks following the procedure. Some patients may still experience tenesmus for a day or two that is partially relieved by oral analgesia. Up to three haemorrhoids can be banded on the same occasion although at the expenses of greater discomfort. RBL can easily be repeated and is often offered as a course rather than one-off treatment; and approximately 4 weeks is usually waited between each session. More severe complications have rarely been reported such as severe local and systemic sepsis and death.
Sclerotherapy
Injection sclerotherapy is an alternative technique used for the treatment of second-degree haemorrhoids, providing at least some temporary symptomatic relief in 69% of patients. , Sclerosant agents used include phenol (5%) in almond oil or sodium tetradecyl sulphate. These are injected into the submucosa around the pedicle of the pile, at the level of the anorectal ring, and cause local inflammation leading to reduced blood flow into the haemorrhoids. The sclerosant also causes fibrosis, which draws minor prolapse back into the anal canal.
Inadvertently deep injections can cause perirectal fibrosis, prostatitis, infection and urethral irritation. Rare but major complications as impotence, fatal necrotising fasciitis and abdominal compartment syndrome following sclerotherapy have been reported. ,
Other treatments
Various other methods have been used less or completely abandoned over the years. Infrared photocoagulation produced less pain compared to RBL and sclerotherapy, but requires an additional device. , Cryotherapy results in unpleasant and foul smelling discharge and, if not performed properly, can destroy the internal anal sphincter producing anal stenosis and incontinence. Anal stretch, based on the belief that haemorrhoidal disease derives from a narrowing of the lower canal, is not performed anymore due to the concerns of damage to the internal anal sphincter and subsequent impairment to anal sphincter function.
Third degree
Traditionally, third-degree haemorrhoidal disease was removed by excisional haemorrhoidectomy. Haemorrhoidectomy as first described by Milligan and Morgan consists of the excision of the diseased anal cushions. Since then, numerous variations to the technique have been described. It can be conducted under local or general anaesthesia; excision of haemorrhoidal cushions can be conducted with scissors, diathermy, laser, vessel-sealing technology (Ligasure), ultrasonic technology (Harmonic Scalpel) or radiofrequency devices; mucosal wounds can be closed (Ferguson, Parks) or left open (Milligan-Morgan). Open and closed haemorrhoidectomies produced similar results for post-operative pain, complications and hospital stay. However, according to a more recent meta-analysis of 11 RCTs and 1326 patients comparing OH and CH, the Ferguson procedure was associated with reduced post-operative pain, faster wound healing, lesser risk of post-operative bleeding, and longer procedure time. The comparison of Ligasure versus diathermy haemorrhoidectomy also showed lower post-operative pain and urinary retention rate, shorter operative time, hospital stay and return to work for Ligasure haemorrhoidectomy. Similar advantages were found for Harmonic Scalpel versus conventional haemorrhoidectomy with regard to post-operative pain and return to work.
Nowadays, two new procedures have been added to the surgical armamentarium for the treatment of symptomatic haemorrhoids, namely stapled haemorrhoidopexy and haemorrhoidal arterial ligation also known as transanal haemorrhoidal de-arterialisation (HAL/THD).
Stapled haemorrhoidopexy
Conventional haemorrhoidectomy deals with the symptoms alone by excising the anal cushions once they bleed or are painful. It does not act on the pathophysiological mechanism that produced the haemorrhoidal disease, the descent of the mucosal anal cushions. In 1998 a transanal circular stapling instrument was used to treat haemorrhoidal disease. The technique consisted of a circumferential mucosectomy and mucosal lifting (haemorrhoidopexy), aimed not to excise the ‘diseased’ haemorrhoidal cushions but rather to reconstitute the normal anatomy and physiology of the haemorrhoidal plexus. Once reduced, the engorged haemorrhoidal tissue will decongest and shrink. It is thought that the stapling device restores the normal anatomy of the anal canal and enables the haemorrhoidal cushions to perform their role in continence, as opposed to haemorrhoidectomy techniques that only excise abundant tissues.
Since its introduction, numerous studies have assessed the short- and long-term efficacy of stapled haemorrhoidopexy, and thus far this technique has produced the largest amount of evidence-based analyses comparing it to classic and modern haemorrhoidectomies. Stapled haemorrhoidopexy produced better results compared to traditional haemorrhoidectomies with regard to early post-operative outcomes such as post-operative pain, bleeding and length of hospital stay, but produced similar results to Ligasure haemorrhoidectomy for post-operative pain, bleeding, urinary retention, difficulty in defaecation, anal fissure, return to normal activities, and hospital stay.
Short-term outcomes are significant improved in stapled haemorrhoidopexy compared to techniques of traditional haemorrhoidectomy but are similar to those achieved by Ligasure haemorrhoidectomy.
Although the rates of anal stenoses are lower compared to traditional open haemorrhoidectomy, faecal incontinence rates and tenesmus are higher. , Furthermore, stapled haemorrhoidopexy is associated with increase recurrence of haemorrhoidal prolapse and anal skin tags, worse quality of life and is less cost-effective when compared to classic haemorrhoidectomy on long-term follow-up. , , ,
Stapled haemorrhoidopexy loses its early advantages compared to classic haemorrhoidectomy when considering faecal incontinence, tenesmus, recurrence rates and quality of life at long-term follow-up. , ,
An additional feature of stapled haemorrhoidopexy is the potential to produce significant and sometimes serious morbidity and even mortality in the immediate post-operative period. These complications, albeit rare and reported mostly as case reports, seriously endanger patients’ lives for what is the treatment of an otherwise benign disease and are often heralded by abdominal pain, urinary retention and fever. It is believed that such complications derive from a full-thickness (or near full-thickness) staple line and resulting anastomotic leakage. Furthermore, distressing new symptoms such as tenesmus are probably related to the mucosal stimulation of the staples and sometimes require a second operation for their removal.
Haemorrhoidal arterial ligation/transanal haemorrhoidal de-arterialisation
This non-excisional technique is based on the occlusion of the haemorrhoidal arterial flow that feeds the haemorrhoidal plexus, by Doppler-guided identification and ligation of the terminal branches of the superior rectal artery using a specially designed proctoscope. The reduction in blood flow to the haemorrhoids leads to shrinkage of the anal cushions. Although the sensitive anoderm below the dentate line is avoided to minimise post-operative pain, this is still present in 18.5% of patients. Anal stenoses are less frequent compared to traditional haemorrhoidectomy, but recurrence rates are higher. After 1 year follow-up, recurrence was present in 4.8% for third-degree and 26.7% for fourth-degree haemorrhoidal disease, although the addition of a mucosal plication (mucopexy) further decreased such occurrence in fourth-degree patients. ,
HAL/THD produced less post-operative pain and anal stenosis but results in higher recurrence rates compared to traditional haemorroidectomy. , The addition of a mucopexy to HAL/THD lowers the long-term recurrence rates to levels similar to traditional haemorroidectomy.
In recent years numerous meta-analyses compared results of HAL/THD to stapled haemorrhoidopexy. Based on the one including the largest number of studies, stapled haemorroidopexy produced higher post-operative bleeding and no significant difference in terms of operating time, post-operative pain, hospital time and return-to-work time. However, the total recurrence rate was higher in the HAL/THD group than in the stapled haemorroidopexy group.
More recently, the HubBle trial compared HAL/THD to RBL for the treatment of second- and third-degree haemorrhoids. The study showed that 1-year post-procedure, 49% of patients in the RBL group and 30% of patients in the HAL group had haemorrhoid recurrence (adjusted odds ratio [aOR] 2.23, 95% confidence interval [CI], 1.42–3.51; P = 0.0005). In a post-hoc analysis comparing a subgroup of patients who underwent an outpatient course of RBL treatment consisting of multiple procedures to patients who received one HAL procedure, the difference in recurrence rate was 37% for RBL and 30% for HAL (aOR, 1.35; 95% CI, 0.85–2.15; P = 0.20). However, these post-hoc analysis results have to be interpreted very cautiously because of the definition adopted for recurrence and different follow-up length between the two groups.
Fourth degree
Haemorrhoidectomy is the main treatment for fourth-degree haemorrhoids (grade 2 evidence) with a recurrence rate of 2–8%. Closed haemorrhoidectomy has reduced post-operative pain, faster wound healing and a lesser risk of post-operative bleeding compared to open procedures. Some authors have suggested that THD may have a role for the treatment of advanced haemorrhoidal disease. , In general, newer technologies significantly reduce post-operative pain and speed up post-operative recovery and return to work at the expense of increased costs due to the disposable devices and increased recurrence rate.
Post-operative problems
Common but transient problems that occur after haemorrhoidectomy include urinary retention, transient incontinence to flatus and faecal impaction. Post-operative pain, bleeding, anal stenosis and fissures also occur and must be mentioned to patients. Permanent anal incontinence is present in up to 6% of patients.
Post-operative pain
Despite the numerous treatments that over the decades have been proposed for the surgical treatment of haemorrhoids, the essential problems encountered remain similar. Whichever technique is used, pain may still be significant in some patients in the post-operative period. Some authors have described post-haemorrhoidectomy pain as being akin to passing glass fragments, such that many patients would rather suffer the discomfort of large prolapsing haemorrhoids for years than submit to surgery. Pain is multifactorial, spasm of the internal sphincter as well as the actual skin wound with its exposed nerves being the most significant factors.
Numerous meta-analyses have evaluated the effects of various adjuncts to oral analgesics (non-steroidal anti-inflammatory drugs, paracetamol and opiates) to control post-operative pain. Local anaesthetic infiltration (pudendal nerve block) has been shown to significantly improve immediate post-operative pain. The effects of oral and topical metronidazole on post-operative pain have been assessed in numerous comparative studies with contrasting results, and unfortunately no meta-analysis is currently available on this topic. All treatments acting on the internal anal sphincter have an effect on post-operative pain. Glyceryl trinitrate (GTN) is thought to decrease muscle spasm and increase anodermal blood flow; in the first 2 post-operative weeks following haemorrhoidectomy it improves pain, healing and resumption of daily activities at the expense of an increased incidence of headaches. Similar results were also achieved with local calcium-channel blockers and botulinum toxin A. , Concomitant lateral internal sphincterotomy at the time of haemorrhoidectomy significantly reduces post-operative pain at the expense of an increase in faecal incontinence rates (1.8% vs. 6.6%).
Local anaesthetics, GTN, calcium-channel blockers and botulinum toxin are useful post-operative adjuncts for post-operative pain. Lateral internal sphincterotomy decreases pain at the expense of an increase in faecal incontinence.
Post-operative haemorrhage
A less frequent problem is post-operative haemorrhage. Bleeding in the immediate post-operative period is usually because of inadequate intra-operative haemostasis. Submucosal adrenaline (epinephrine) injection has been shown to be effective for addressing bleeding after excisional haemorrhoidectomy. Secondary bleeding is more often as a result of post-operative infection and it affects approximately 5% of patients undergoing haemorrhoidectomy. The advocated treatment is antibiotics. Following stapled haemorrhoidectomy, bleeding may follow the rare staple-line dehiscence.
Anal stenosis
Post-haemorrhoidectomy anal stricture is an uncommon occurrence seen in only 3.7% of haemorrhoidectomies, and represents a technical failure to leave sufficient mucocutaneous skin bridges. The stricture usually presents 6 weeks post-operatively and is treated with anal dilatation and stool softeners.
Thrombosed haemorrhoids
Prolapsed thrombosed internal haemorrhoids ( Fig. 17.2 ) and perianal haematoma are best managed conservatively. The course of these conditions is self-limiting and normally symptoms resolve within a couple of weeks. Laxatives, stool softeners, sitz baths, ice packs, oral and topical analgesia are often helpful. Perianal haematomas presenting very early may be considered for surgical excision or drainage. Very rarely prolapsed thrombosed internal haemorrhoids with gangrenous component may also require excision ( Fig. 17.3 ).
Anal fissure
Introduction
An anal fissure is an ulceration of the squamous epithelium of the anal canal distal to the dentate line. It is a common complaint in the colorectal clinic. Medical treatment is simple but is frequently not adhered to and is not successful in a significant number of cases. Surgical management has become less frequently used due to the application of botulinum toxin.
Aetiology
Two main factors contribute to the formation of posterior anal fissures. First, hard faeces contribute by increasing the local trauma on the anal mucosa, although 25% of fissures present in patients without constipation. Second, affected patients frequently present with internal anal sphincter hypertonia, which in turn, enhances the traumatic effects of the hard faeces and provokes a relative tissue ischemia with decreased blood supply to the anal mucosa. The internal anal sphincter alone appears to be responsible for the hypertonia. Hypertonia of the internal anal sphincter is caused by the decreased production of nitric oxide by the internal sphincter, a substance that normally relaxes muscle contraction. This produces the high mean resting anal pressures frequently seen in affected patients.
After the initial tear, a vicious cycle of non-healing and repeated trauma leads to development of chronic deep fissures. In this cycle, local pain increases sphincter reflex contraction, which in turn worsens the effect of hard stools and local tissue ischaemia. This mechanism can explain the achievement of high healing rates with therapies, which reduce the sphincter tone and improve the local blood flow.
Although this mechanism is valid for most patients, other factors have to be considered in elderly patients or post-partum patients where anal fissures have been reported in the presence of normal or hypotonic internal sphincters (see anterior anal fissures later) .
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