Endometriosis

by Jaime Vasquez, M.D.

Center for Reproductive Health
326 21st Avenue N
Nashville, TN 37203
(615) 321-8899

The care of endometriosis requires accurate diagnosis and effective treatment. At least 5.5 million women in the United States and millions more around the world are affected with endometriosis. The symptoms, including pain, nausea, vomiting, diarrhea, fatigue, and low-grade fever, can be severe.

Controversy still exists concerning the optimal treatment of endometriosis and their related pain and infertility. Surgical intervention has been the preferred mode of therapy. Multiple reasons for the surgical approach have been invoqued: a) it is the only way to make a histologic diagnosis b) the diagnosis is made and surgical therapy is easily accomplished simultaneously c) it allows the patient fast control of her symptoms e) it also increases conception rates without resorting to prolonged and expensive medical therapy (usually required for 6 months). Conservative surgical treatment is indicated in women of reproductive age.

ENDOMETRIOSIS: THE DISEASE

Endometriosis is a progressive, often debilitating disease that affects 10-35% of women during their reproductive years. Among gynecologic disorders, endometriosis is second only to leiomyomata in frequency and accounts for 25% of all laparotomies performed by gynecologists. Endometriosis may significantly impair health, quality of life, and fertility.

Sampson first defined endometriosis in 1940 as the presence of ectopic tissue, which possesses the histologic structure, and function of uterine mucosa. Endometriosis affects 23-40% of infertile women; 1-5% of women with proven fertility; and 20-40% of patients with pelvic pain. A number of theories exist regarding the development of endometriosis.

Endometriosis patients commonly present with pelvic pain or infertility. In diagnosing the condition. the classic history and physical exam include dysmenorrhea, dyspareunia and infertility, notably with tender, nodular uterosacral ligaments; fixed retroverted uterus; and thickened parametrium. However, visualizing the endometriosis at laparoscopy can only make a definitive diagnosis; the entire pelvis should be inspected using a two- or three-puncture technique.

Some reports published in the past decade have suggested that mild endometriosis does not require treatment; five observational studies of 154 patients responded a pregnancy rate of 60%. However, in a study of women undergoing therapeutic donor insemination, Jansen found that the probability of pregnancy among women with minimal endometriosis was one-third that of patients without endometriosis.

Mild endometriosis may cause infertility due to the presence of peritoneal prostanoids, producing either corpus luteum dysfunction or altered tubal motility. Mild endometriosis may also result in increased numbers of peritoneal macrophages that may be hyperactivated and may phagocytize the sperm or egg, or otherwise affect implantation. Some researchers have also postulated a disturbance of folliculogenesis or ovulation.

SURGICAL THERAPY OF ENDOMETRIOSIS WITH LASERS

Electrocautery and laser (free beam or contact) are currently the preferred methods for surgical ablation of endometriosis. Mechanical methods are also used. Mechanical methods have the advantage of using simple inexpensive instruments, but they are not hemostatic and also produce extensive tissue damage leading to extensive pelvic adhesive disease. Electrocautery and lasers are hemostatic, but dissection with either of these instruments is somewhat difficult as they are unselective, with the potential for abdominal organ injuries. Presently, although an ideal dissecting tool is not available, we have developed new technologies with increased effectiveness and decreased tissue damage.

The Cavitational Ultrasonic Surgical Aspirator (CUSA)

The technique for laparoscopic excision of endometriosis using a cavitational ultrasonic surgical aspirator was developed. Removal of endometriosis was performed using a titanium probe developed for a 10-mm laparoscopic port and approved by FDA. The ultrasonic laparoscopic probe consisted of an acoustic vibrator, a coupling device, a removable tip, and a protective flue. The vibrations from the acoustic vibrator (magnetostrictive device) were conveyed to the operating tip (3 mm in diameter) through a coupling piece. The magnetostrictive device consisted of nickel alloy laminations 10.8 cm in length that transformed electrical energy into mechanical motion of the hollow titanium tip vibrating at a frequency of 23 kHz. This frequency was selected as the lowest inaudible frequency with maximal practical amplitude. The excursion of the tip (amplitude setting) was arbitrarily set, with a fixed stroke of 200 µm in all cases as recommended by others to remove tissue within a 1-2 mm radius of the vibrating tip. The tip was tapered to obtain greater amplitude and ablation efficiency. The tip of the device, placed in contact with the endometriosis implants and adhesions destroyed and emulsified the cell membranes, which were irrigated and removed through a built-in suction tube. The resulting debris and irrigating fluid were removed through the hollow central portion of the probe. Vessels larger than 0.5mm in diameter, nerves and fibrous tissue capsules, all of them collagen-rich structures, rebound with the ultrasonic vibration waves emitted by the CUSA, and consequently they were left unimpaired by the procedure. A very accurate sensation of the consistency of tissues was obtainable through the tip of the device in contact with them. This tactile feedback was quite helpful in enabling the surgeon to differentiate between target tissues. In conclusion, the utilization of the CUSA led to increase visibility, as compared with lasers and electrosurgery. The relative efficacy of the CUSA as compared with other surgical tools needs to be evaluated in prospective randomized studies.

MEDICAL THERAPEUTIC APPROACHES FOR ENDOMETRIOSIS

Treatment options include medical therapy, surgery, or a combination approach. Danazol, a 1, 7-alpha-ethinyl testosterone derivative, has proven beneficial but produces serious side effects: hot flashes, vaginal bleeding, acne, weight gain, hirsutism, voice changes, decreased libido, decreased breast size, atrophic vaginitis, depression, alopecia, persistent amenorrhea, and increased liver enzymes (CPK, LDH, SGOT, SGPT). Danazol is also quite expensive and some recent prospective randomized studies suggest that it may not be more effective than placebo in improving fertility rates.

More recently, GnRH agonists have been utilized to induce a pseudomenopause by producing a hypogonadal and hypoestrogenic state. GnRH agonists may effectively suppress levels of FSH, LH, estradiol and estrone throughout the duration of treatment. While both danazol and GnRH agonists suppress free estradiol, the suppression achieved with a GnRH agonist is comparable to that achieved in an oophorectomized state. Dickey et al. demonstrated that a significant hypoestrogenic state is required to treat endometriosis.

Side effects with GnRH agonist therapy are related to the necessary hypoestrogenic state: amenorrhea, hot flashes, and vaginal dryness. These side effects are not well tolerated by most patients. Moreover, GnRH agonists may not be the ideal therapeutic approach in patients with extensive disease, where surgical therapy alone or in combination with medical therapy may be required.