Unlike traditional hemorrhoidectomies, such as Ferguson or Milligan-Morgan,
PPH does not involve excising either the hemorrhoidal tissue or the anal
mucosa.
With PPH, a ring of mucosa, submucosa, and hemorrhoidal vasculature is excised
proximal to the dentate line. A mucosal anastomosis is also performed using a
circular surgical stapler, raising the vascular cushions to a more normal
anatomic location within the anal canal. The hemorrhoids are circumferentially
devascularized, so they eventually shrink and involute.
A primary reason PPH causes significantly less pain and patient "downtime" is
that the excision is performed above the dentate line in the anal canal,
removed from sensitive nerve endings.
(Flash Animation: PPH versus traditional hemorroidectomy)