DEFINITION
Haemorrhoids are defined as the symptomatic enlargement and distal displacement of the normal anal veins.
They are a very common human disease that has been known since the dawn of time, as even Hippocrates and Egyptian papyruses before described remedy used to treat this condition.
Haemorrhoids can be external (which are considered swellings of the skin and endoderma round the anus) or internal, which are classified in four grades:
Grade I — Haemorrhoids bleed and may protrude into, but do not prolapse out of, the anal canal.
Grade II — Haemorrhoids prolapse on defecation but reduce spontaneously.
Grade III — Haemorrhoids require manual reduction.
Grade IV — Haemorrhoids cannot be reduced. They are permanently prolapsed
SYMPTOMS
Commonly, the patient suffering from haemorrhoids complains of painless rectal bleeding while passing stools, as he can clearly see blood drips into the toilet. The blood is usually bright as the haemorrhoids have direct arteriovenous communication. Prolapsing haemorrhoids may cause perineal irritation or anal itching. Usually, haemorrhoids don’t cause pain, unless thrombosis has occurred, especially when a 4th degree haemorrhoid becomes strangulated.
DIAGNOSIS
The diagnosis must be carried out basing on the patient’s history and on a careful examination, including digital examination and anoscopy, in order to exclude different pathologies of the GI tract such as colorectal neoplasy.
Anoscopy: overview, preparation, complications
PATHOGENESIS
Although the exact pathophysiology of the disease is still poorly understood, nowadays the most accepted theory is the sliding anal canal lining. This proposes that haemorrhoids are the pathological term to describe the downward displacement of the anal cushions (masses of sub epithelial tissue, located in the left lateral, right posterior, and right anterior quadrants of the anal canal, that seal the anal canal and maintain continence).
The anal cushions of patients with haemorrhoids show significant pathological changes. These changes include abnormal venous dilatation (*), vascular thrombosis, degenerative process in the collagen fibers and fibroelastic tissues, distortion and rupture of the anal sub epithelial muscle (#).
This degradation of supporting tissues in the anal cushions can be caused by a lot of different enzymes and mediators. Among these, matrix metalloproteinase (MMP), a zinc-dependent proteinase, is one of the most potent enzymes, being capable of degrading extracellular proteins such as elastin, fibronectin, and collagen. MMP-9 was found to be over-expressed in haemorrhoids, in association with the breakdown of elastic fibers. Physiologically, MMP-9 plays an important role in wound healing, angiogenesis, inflammation, tumour invasion, and metastasis, while its overexpression is frequently associated with several neoplasies.
Wikipedia: MMP
BRENDA the comprehensive enzymes information system
Furthermore, increased microvascular density was found in haemorrhoidal tissue, due to the angiogenesis-related factors VEGF and TGF-β, suggesting that neovascularization might be another important phenomenon of haemorrhoidal disease.
Based on the histological findings of abnormal venous dilatation in haemorrhoids, dysregulation of the vascular tone might play a role in haemorrhoidal development.
In haemorrhoids, nitric oxide synthase, an enzyme that synthesizes nitric oxide from L-arginine, was reported to increase significantly. This, in addition to the increased production of other endothelial relaxing factors, such as prostaglandins and endothelium-derived hyperpolarizing factor, leads to an increase of smooth muscle cells relaxation.
NOS
Identification of anti-endothelial cell antibodies in patients with chronic anal fissure
In addition, an immunologic cause may be involved in the development of haemorrhoids, as anti-endothelial cells autoantibodies (AECAs) were found in patients with anal fissure or haemorrhoids. These antibodies can play a role in the ischemic process that leads to the symptoms of the disease.
Role of nitric oxide and other endothelium-derived factors
THERAPY
There are several different degrees of non-surgical treatment for haemorrhoids, depending on their grade, as shown in the following table.
* Dietary and lifestyle modifications
This includes an increasing intake of fibers, which reduces straining on defecation. However, this dietary change can only help with bleeding and is poorly effective in reducing prolapsing and pain. In addition, people suffering from haemorrhoids should reduce the consumption of fats, increase the exercise and abstain from straining and reading on the toilet.
* Medical treatment
Oral flavonoids: they appear to be capable of increasing vascular tone, reducing venous capacity, decreasing capillary permeability, and facilitating lymphatic drainage as well as having anti-inflammatory effects. Although their precise mechanism of action remains unclear, they are used as an oral medication for haemorrhoidal treatment, particularly in Europe and Asia.
Flavonoids
Oral calcium dobesilate: decreases capillary permeability, inhibits platelet aggregation and improves blood viscosity; thus resulting in reduction of tissue oedema. In conjunction with fiber supplement, it provides an effective symptomatic relief from acute bleeding, and it is associated with a significant improvement in the inflammation of haemorrhoids.
Wikipedia: dobesilate
Topical treatment, such as suppositories, ointment, etc.: they can contain various ingredients as local anaesthetics, corticosteroids, antibiotics and anti-inflammatory drugs. Although we lack strong proofs of their efficacy, some studies demonstrated significant benefits in some grades of haemorrhoids.
(Conservative treatment of acute thrombosed external hemorrhoids with topical nifedipine, 2001)
* Non-operative treatment
Sclerotherapy (Mitchell technique): its aim is to cause thrombosis of the vessels and to cause fibrosis to reduce the prolapse. The solutions used are 5% phenol in oil, vegetable oil, quinine, and urea hydrochloride or hypertonic salt solution. Complications are few, although bacteraemia can be associated with this treatment.
Rubber band ligation: it causes ischemic necrosis and scarring, leading to fixation of the connective tissue to the rectal wall. Placement of rubber band too close to the dentate line may cause severe pain due to the presence of somatic nerve afferents and requires immediate removal. It is performed by grasping and pulling the mucosa into a rubber band applier, commonly called the Barron gun.
Radiofrequency ablation: it is a relatively new procedure and it is performed with a ball electrode connected to a radiofrequency generator. This is placed on the haemorrhoidal tissue and causes the contacting tissue to be coagulated and vaporized.
Infrared photocoagulation: it coagulates tissue and vaporizes water in the cell, causing shrinkage of the haemorrhoid mass. The necrotic tissue after treatment heals spontaneously with fibrosis.
Optimal nonsurgical treatment of hemorrhoids: a comparative analysis of infrared coagulation, rubber band ligation, and injection sclerotherapy.
Sources
Haemorrhoids: from basic pathophysiology to clinical management
Surgical management of haemorrhoids
