The hemorrhoidal cushions appear predictably in the right anterior, right posterior, and left lateral positions, although there may be intervening secondary hemorrhoidal complexes that blur this classic anatomy. The blood supply is similarly constant, derived from the superior rectal artery, a branch of the inferior mesenteric; from the middle rectal arteries arising from the internal iliac arteries; and from the inferior rectal arteries arising from the pudendal arteries. The venous drainage transitions from the portal venous system above the level of the dentate line to the systemic venous system below this level.
The vascular cushions form the termination of the vascular supply within the anal canal and contribute to the maintenance of anal continence.[6] hemorrhoids occurs as the result of abnormalities within the connective tissue of these cushions, producing bleeding with or without prolapse of the hemorrhoidal tissue.[7] This can occur as the result of excessive straining and chronic constipation.[8] A clear understanding of the pathophysiology is important when considering therapeutic interventions. At the earlier stages of disease progression, when the major manifestation is transudation of blood through thin-walled damaged veins or arterioles, ablation of the vessels should be adequate. Conversely, in late stages of the disease, when there is significant disruption of the mucosal suspensory ligament, fixation of the mucosa to the underlying muscular wall is required for effective therapy.Internal anal sphincter dysfunction may play a role; a number of investigators have demonstrated increased internal anal sphincter tone in patients with hemorrhoids. In reality, a combination of all of these factors is probably important for the ultimate development of large prolapsing internal hemorrhoids.
The standard classification for hemorrhoids is as follows:
- Stage 1: bleeding
- Stage 2: protrusion but spontaneous reduction
- Stage 3: protrusion that requires manual reduction
- Stage 4: irreducible protrusion
Although this staging system tends to correlate with the patient’s symptoms, it is unclear whether it can be completely relied on when making therapeutic decisions. As outlined later, it is important to consider the relative role of both internal hemorrhoidal tissue and external hemorrhoidal skin tagging when choosing a modality for complete resolution of all of the patient’s symptoms.
