CONTEMPORARY MANAGEMENT OF ABNORMAL UTERINE BLEEDING
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TREATMENT OF THE PATIENT WITHOUT INTRACAVITARY PATHOLOGY Comparison of Traditional Hysteroscopic Techniques for Endometrial Ablation Philip G. Brooks, MD
For generations physicians have searched for alternatives to hysterectomy to correct the problem of excessive uterine bleeding from benign causes in women who were unable or unwilling to undergo major surgical procedures because of their potentially serious emotional or physical consequences. The modem advances in technology, efficacy, and safety of performing hysteroscopy created the ability to operate telescopically within the uterine cavity, making it possible to develop procedures for this purpose. It is ironic that the hysteroscope, originally developed for the evaluation of abnormal bleeding more than 100 years ago, is currently still used for this primary purpose. ENDOMETRIAL LASER ABLATION
Early attempts at destroying the endometrium and its surface vascular supply using chemicals, radiation, and photoinactivation were discarded because of their high failure rates and their toxicity. It was not until Coldrath? developed the technique of hysteroscopically directed laser endometrial ablation that the hope for effective, relatively safe, minimally invasive hysteroscopic ablation became a reality. Prompted by the revolutionary miniaturization of hysteroscopes, the improvement in safety and effectiveness of distention media, and the successful development of cold light transmission, intrauterine exploration and surgical
From the Department of Obstetrics and Gynecology, School of Medicine, University of California, Los Angeles; and Cedars-Sinai Medical Center, Los Angeles, California
OBSTETRICS AND GYNECOLOGY CLINICS OF NORTH AMERICA VOLUME 27 • NUMBER 2 • JUNE 2000
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manipulation techniques developed rapidly and gave rise to investigation of procedures intended to destroy the endometrium. The first method, reported by Goldrath in 1981,9 used Nd:YAG laser energy delivered through the operative channel of the hysteroscope. Of the different types of medical lasers available at that time, the Nd:YAGlaser energy was chosen because of its greater penetration depth and beam scatter, factors believed to increase the depth of endometrial destruction and, ultimately, the success rate. In addition, Nd:YAG laser energy is not absorbed by clear fluids, hemoglobin, or melanin, as is the case with other lasers, making the Nd:YAG particularly useful for intrauterine surgery. The original technique of endometrial laser ablation, described as the dragging or touch method, delivered laser energy through a flexible quartz fiber, the tip of which was directed to contract and then drag along the endometrial surface to vaporize, desiccate, and coagulate the tissue to a depth of 4 to 5 mrn. In 1987, Loffer" reported a modification of endometrial laser ablation, referred to as the blanching or nontouch technique, wherein the laser fiber is held a short distance away from the endometrial surface when the laser is fired. The laser energy is transmitted across the distention medium to the uterine surface, producing the same effect on the surface of the endometrium. Because of the configuration of the uterus and the inability of either method to destroy all areas of the endometrial cavity at the same angles of approach, many surgeons preferred a combination of the touch and nontouch techniques. To eradicate the production of smoke or steam during the firing of the laser at endometrial tissue, fluid distention media were selected for use with endometrial laser ablation. As opposed to electrosurgical energy, laser energy can pass freely through electrolyte-containing fluids. Low-molecular-weight, low-viscosity, iso-osmolar and isotonic solutions such as saline or Ringer's lactate solutions, can be selected as distention media in addition to high-molecular-weight, high-viscosity liquids, such as dextran-70 (Hyskon). Early results reported on small numbers of cases and for short periods of time by Goldrath" and by Loffer'" were encouraging, with good results, defined as eumenorrhea or better, in approximately 90% of cases. Longer follow-up studies" began to show increasing rates of failure and the need for further surgery, however. These data, coupled with the cost of lasers and the need for extensive courses and additional credentialing processes by hospital departments, resulted in laser ablation not being enthusiastically received by a large body of clinicians; only a few skilled specialists became proficient with the procedure. RESECTOSCOPIC ENDOMETRIAL ABLATION
The most significant stimulus to the adoption of endometrial ablation for the conservative management of abnormal bleeding was the adaptation of the urologic resectoscope to gynecologic operative procedures. Hallez et a1,10 Neuwirth and Amin," and DeChemey and Polan" in the English-speaking literature and Linn in the Japanese literature published reports on the successful management of excessive bleeding using electricity and resecting loops. As the numbers of cases accumulated," data presented to the Food and Drug Administration were sufficient to warrant approval of the resectoscope for gynecologic indications in December 1989. Subsequently, the lower cost, equal effectiveness, and greater ease of teaching and learning this technique caused the resectoscope to become a standard tool for the practicing gynecologist in the management of abnormal uterine bleeding.
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Refinement of techniques and methods was evident when Vancaillie" and Townsend et al" reported that the use of a roller-end electrode was safe, simple, easy to teach, and relatively effective. Higher amenorrhea rates achieved with the wire loop resection of the surface tissue led to a worldwide preference for the combination of resection with a loop electrode (Fig. lA) (sometimes termed transcervical resection of the endometrium [TCRE], endometrectomy, or endomyometrial resection [EMR]), plus coagulation (using a roller-ball, roller-barrel, or thick coagulating loop electrode [Fig. 1]). Brooks and Serdenv " reported that the procedure was made even easier and was of shorter duration and associated with less blood loss and less intravasation of distention medium when the endometrium was thinned with a preoperative medication, such as a Gonadotropin-releasing hormone (GnRB) agonist. Corson et al," in a prospective, randomized, controlled study, showed that the use of a dilute solution of vasopressin injected directly into the cervical stroma preoperatively further reduced the bleeding during operative hysteroscopy and minimized the amount of distention medium intravasated into the patient's circulatory system. Another adaptation of urologic resectoscopic methodology was the use of a vaporizing electrode for vaporization of intrauterine myomata' and endometrial ablation," 17 These electrodes (Fig. 2) were developed originally for transurethral vaporization of the prostate. This technology takes advantage of the effect of edge density (the propensity of electrons to concentrate at the edges of nonspherical electrodes [Fig. 3]) resulting in greater power delivery to tissue. Application of these vaporizing principles to resection of uterine myomas and to endometrial ablation was an easy adjustment. Using power settings of up to 200 W of
Figure 1. Resectoscopic electrodes. A, 90° wire loop. B, Roller-ball. C, Resectoscopic roller-barrel (left), and thlok-coaqulatlnq (right) electrodes.
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Figure 3. The number of edges of grooved vaporizing electrodes where electrons concentrate (edge density).
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Figure 4. Endometrial surface with a single groove made by a wire loop electrode.
Figure 5. Indentation made by vaporization electrode (left) adjacent to resected groove (right) made by a wire loop electrode.
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cutting current, these electrodes are rolled along the surface of the preoperatively thinned endometrium, vaporizing the surface to a depth of 3 or 4 mm, with additional thermal injury to a depth of 3 or 4 mm. Although a higher power setting theoretically increases the risks of perforation and thermal injury to adjacent organs, its advantages include less bleeding! less intravasation, and the faster procedure. The basic technique of resectoscopic endometrial ablation is as follows: after appropriate preoperative thinning of the endometrium or after a thorough curettage, preferably timed in the early proliferative phase of the menstrual cycle, approximately 2 mL of dilute pitressin (5 U in 20 mL saline) are injected directly into the cervical stroma in three of four areas. The cervix is dilated, and the hysteroscope with sheath is inserted into the cervical canal, either under direct vision through the lens and optic or indirectly with the use of a video camera and video monitor. After appropriate inspection of the landmarks and endometrial cavity; a wire loop electrode is used to resect several strips of endomyometrium, to a depth of 4 mm (Fig. 4). Resected tissue is used for pathologic examination and documentation of the absence of cellular atypia. After a few strips are resected initially from the posterior uterine wall, resection of almost all of the remaining surface with the loop electrode by vaporization is performed (Fig. 5). Desiccation or coagulation of all the remaining surface area, using a vaporizing roller-ball or roller-barrel, or thick coagulating loop electrode follows. Special care is taken when destroying the endometrium at the cornual areas because of the generally thinner muscle wall at those points, with the potential increased risk of transuterine thermal injury or perforation. At the end of the procedure, all areas are charred and coagulated (Fig. 6), and bleeding points are checked by decreasing the intrauterine pressure. Fulguration of bleeding points is accomplished, and the procedure is concluded. After the procedure, menstrual pattern improvement is commonplace. Short-term and long-term studies show amenorrhea rates of 20% to 50%, overall improved bleeding patterns (including amenorrhea) in 85% to 95%, with failure rates of 5% to 10%, which require additional surgery or hysterectomy.
Figure 6. Hysteroscopic appearance of endometrial cavity after completion of endometrial ablation.
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References 1. Brooks PG: Resectoscopic myoma vaporizer. J Reprod Med 40:791-795, 1995 2. Brooks PG: The use of the VaporTrode vaporization electrode in operative hysteroscopy. GyneTrends 1:1-3, 1997 3. Brooks PG, Loffer FD, Serden SP: Resectoscopic removal of symptomatic lesions. J Reprod Med 34:435--438, 1989 4. Brooks PG, Serden SP: Preparation of the endometrium for ablation with a single dose of leuprolide acetate depot. J Reprod Med 36:477-480, 1991 5. Brooks PG, Serden SP, Davos I: Hormonal inhibition of the endometrium for resectoscopic endometrial ablation. Am J Obstet GynecoI164:1601-1606, 1991 6. Corson SL, Brooks PG, Serden SF, et al: Effects of vasopressin administration during hysteroscopic surgery. J Reprod Med 39:419-423, 1994 7. DeCherney A, Polan ML: Hysteroscopic management of intrauterine lesions and intractable uterine bleeding. Obstet Gynecol 61:392-394, 1983 8. Goldrath MH: Intrauterine laser surgery. III Keye WR (ed): Laser Surgery in Gynecology and Obstetrics. Boston, GK Hall, 1985, pp 93-96 9. Goldrath MH, Fuller T, Segal S: Laser photovaporization of endometrium for the treatment of menorrhagia. Am J Obstet GynecoI140:14-19, 1981 10. Hallez JP, Netter A, Cartier R: Methodical intrauterine resection. Am J Obstet Gynecol 156:1080-1083, 1987 11. Lin B-L: The development of a new hysteroscopic resectoscope and its clinical applications on transcervical resection and endometrial ablation. Japanese Journal of Gynecologic and Obstetric Endoscopy 4:56-61, 1988 12. Loffer FD: Hysteroscopic endometrial ablation with the Nd:YAG laser using a noncontact technique. Obstet GynecoI 69:679-682, 1987 13. Neuwirth R5, Amin HK: Excision of submucous fibroids with hysteroscopic control. Am J Obstet GynecoI131:95-98, 1983 14. O'Connor H, Magos A: Endometrial resection for the treatment of menorrhagia. N Engl J Med 335:151-156, 1996 15. Townsend DE, Richart RM, Paskowitz RA, et al: "Roller-ball" coagulation of the endometrium. Obstet Gynecol 76:310-314, 1990 16. Vancaillie TG: Electrocoagulation of the endometrium with the ball-end resectoscope ("rollerball"). Obstet Gynecol 74:425--428, 1989 17. Vercellini F, Oldani 5, Milesi M, et al: Endometrial ablation with a vaporizing electrode. Acta Obstet Gynecol Scand 77:683-686, 1998
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