Implants may be vaporized using high-power-density energy over a short time. This induces a rapid increase in water temperature, resulting in vaporization and tissue destruction. If carbonization can be avoided, this method is very precise. It requires a focused, extremely high-power density, such as that achieved with the superpulse or ultra-pulse CO2laser.
Coagulation occurs with lower energies and results in lower temperatures at the tissue level. At 60° to 80°C, there is a loss of intracellular water and coagulation of protein, resulting in cell destruction. Because the depth of penetration is not always predictable, this technique is considerably less precise than vaporization. In addition, while lasers are a rapid means of performing this method, bipolar electrical current or even monopolar techniques can be used.
No randomized comparisons of these approaches have been conducted. Only 1 retrospective, comparative trial exists. Winkel and Bray reported the results of a 24-month follow-up of 240 women with endometriosis and pelvic pain who underwent surgical treatment in the form of excision alone, laser coagulation alone, or laser coagulation plus medical therapy.7 Twelve months after surgery, 96% of excision patients were pain-free compared with 69% of those undergoing coagulation. At 2 years, the corresponding figures were 69% and 23%, respectively. While this seems to indicate that excision is superior to coagulation, the retrospective study design makes such a conclusion suggestive at best. For example, excision may have been used in easier, less risky situations, whereas in difficult cases, only coagulation may have been performed. The resulting success rates would thus reflect the amount of disease discovered, not the type of surgery. To truly clarify this issue, a randomized trial is needed.
Only 40% of patients surgically treated for endometriosis experience pain relief as a direct result of surgery.
As mentioned earlier, numerous weapons have been employed to destroy endometriosis lesions: the CO2, KTP, Nd:YAG, and argon lasers; ultrasonic shears; monopolar electrical energy; and bipolar electrical energy. No comparisons of the efficacy of these instruments have been conducted.
Treating endometriomas. Ovarian cysts are common in the endometriosis patient, and the method by which they are surgically treated may be vital to the outcome. The goals of treating ovarian endometriomas are removing all ectopic endometrium in the ovary, reducing ovarian trauma, preserving follicles, and minimizing postoperative adhesion formation.8
Two types of endometriomas are recognized. The least common is contained entirely within the ovary. More widespread is an inverted anterior ovarian cortex with adhesions and implants on the surface, which is frequently adherent to the broad ligament. The latter type represents more than 90% of ovarian endometriomas.9
Before operating, the ovaries should be freed of all adhesions. The endometrioma may open spontaneously during this process; if not, incision and drainage are warranted. At this point, the cyst wall may be stripped, excised, or drained as indicated. Stripping involves separating the cyst wall from the ovary and slowly peeling them apart. In the Putman-Redwine technique, the opening to the endometrioma is circumscribed with a laser or electrosurgery, followed by dissection down to the cyst wall. The cyst wall and ovary then are separated sharply and bluntly until the cyst wall is removed, frequently intact. Excision also can be accomplished in a manner similar to a wedge resection. However, while removal of the endometrioma is invariably complete with this method, the potential for adhesion formation is higher.10
The vaporization or coagulation of cyst walls also has been described. A randomized trial comparing removal of the cyst wall versus fenestration and aspiration of cyst contents clearly demonstrates improved results with removal, whether the desired outcome is pain relief, fertility, or a lower rate of reoperation.11
The value of closing the ovary after endometrioma removal has been greatly debated, with no consensus among surgeons. Data suggest more adhesions form with suturing of the ovary than without closure, but it is unclear whether this applies to all sizes of defects.12
Ancillary procedures. Adhesiolysis is an important step in the restoration of normal pelvic and abdominal anatomy. While simple lysis of adhesions is adequate if they were formed following infection, most experts believe a more complete approach is required for the endometriosis-induced adhesion. This is because of the relatively high incidence of endometriosis present within the adhesion itself. Thus, removal of the adhesion by lysing both boundaries of the scar tissue and connecting structures is preferable. The instrumentation is of little consequence as long as precision and hemostasis are maintained.
To minimize adhesion reformation, adhesion-prevention adjuvants should be used. Four are presently available, including Interceed (Ethicon Inc, Somerville, NJ), a cellulose based barrier; Seprafilm (Genzyme Corp, Cambridge, Mass), a hyaluronidase-impregnated barrier; Preclude (W.L. Gore and Associates Inc, Newark, Del), a non-absorbable barrier composed of the proprietary Gore-Tex; and Intergel (Lifecore Biomedical Inc, Chaska, Minn), a thick solution placed within the peritoneal cavity that provides widespread adhesion prophylaxis. All adjuvants currently available have been associated with decreased adhesion reformation in randomized clinical trials.13 They can be applied either laparoscopically or abdominally.