Endometriosis is the etiology in almost one-third of all gynecological admissions in the United States. It takes close to 12 years from first symptoms to confirmatory diagnosis. Early surgical intervention will promote earlier diagnosis. This chapter describes surgical management. The reader is referred to other sources for in-depth discussion of medical management.
Scope of the Problem
The problem of endometriosis is large. It is estimated that one in three gynecological admissions in the United States are related to this condition.  Diagnosis may be elusive, and many of the symptoms are vague and can represent a variety of gynecologic conditions. Almost 1 in 10 women of reproductive age suffers from the burden of this condition, and over 69 billion dollars was spent in 2009 on treating this condition. [2,3] As many as 40 percent of infertile couples and 9 percent of women with chronic pelvic pain demonstrate the presence of endometriosis.  Endometriosis is a disease with a genetic component, and as many as 5–7 percent of all women with the disease have a first-degree relative afflicted. The mode of inheritance is most likely polygenetic/multifactorial method of inheritance, as opposed to Mendelian. 
Endometriosis occurs when endometrial glands and stroma implant on extra-uterine surfaces. Classically, these lesions may be present on the pelvic and parietal peritoneum, the ovaries, the cul-de-sac, and uterosacral ligaments or bowel. The most common theory was developed by Dr. Sampson in the early part of twentieth century. He proposed retrograde menstruation allows the migration and implantation of ectopic glands. Support of this theory includes the preponderance of lesions in the cul-de-sac due to gravity, as well as the left hemi pelvis due to the recto sigmoid location. Other common theories for the etiology of endometriosis include coelemic metaplasia, hematogenous spread, lymphatic spread, and stem cell transplants spread via the bone marrow.
Whichever mechanism is ultimately proven to be the dominant one, changes at the molecular level also need to occur to influence the induction of the disease. There are four molecular characteristics that are associated with endometriosis. These include a genetic predilection, estrogen dependence, progesterone resistance, and local inflammation. Combination of these factors all contribute to the expression of this disease.