Phillip G. Brooks, MD

For the gynecologist, the         introduction of the resectoscope revolutionized the management of         submucous myomata that cause uncontrollable uterine bleeding,         infertility and pregnancy wastage, and the con-servative control of         persistent and excessive uterine bleeding unrelated to uterine filling         defects. Electrodes such as wire loops, rollerballs, and roller         cylinders initially were used for the resection of myomas and polyps and         endometrial ablation procedures. Numerous studies have confirmed the         success and safety of procedures with resectoscopes to correct these         problems.         

However, one of the more significant         difficulties encountered during resection of myomata and/or the         endometrium (during ablation procedures) is the accumulation         of tissue "chips," requiring repeated withdrawal of the         resectoscope, removal of resected tissue, and reinsertion of the         resectoscope. This may result in prolongation of the procedure and an         increased risk of introducing infection.

In 1995, stimulated by the enormous         urologic success of the vaporization technique for treatment of         benign prostatic hypertrophy, I began a trial with a new vaporization         instrument, the Grooved VaporTrode Vaporization Electrode, to         destroy myomata and for endometrial ablation.

The first vaporizing electrode         developed by CIRCON ACMI was the VaporTrode Grooved Bar (Figure 1).         The electrode has both thin ridges for high current density and         effective vaporization, and a contact area between the grooves which         separates the ridges. This configuration utilizes the long-known         property of electricity called "edge density," which is the         concentration of electrons and therefore energy at the edges of a         non-spherical electrode. Using higher wattage and the Grooved VaporTrode,         urologists and gynecologists are able to more efficiently vaporize         tissue in contact with the electrode. For gynecological use, the         result is the actual destruction and/or morcellation of myomas and         endometrial surfaces. Because of the tissue heat produced by the energy         density or concentration of energy, blood vessels are coapted and         sealed, markedly reducing the risk of bleeding and intravasation of         distention media. Additionally, in contrast to resection, vaporization         allows the morcellation of myomas into several fragments easily         extracted from the uterine cavity instead of numerous smaller chips that         require repeated extractions to clear the field of view.

The basic operating room setup is the         same as for any other resectoscopic procedure. We use a CIRCON ACMI         rotating continuous flow resectoscope with a 12° telescope. Instead of         a wire loop, a Grooved VaporTrode is used. Three VaporTrode         configurations are available - fluted, spiked, and grooved -         designed to accommodate diverse surgical techniques and types of         electrosurgical generators. Depending on the capabilities of the         generator, the wattage is set from 160W to 200W in a pure CUT waveform.         (Some urologists use up to 300W for electrovaporization of the         prostate.)

Management of Myomas and Giant         Polyps

I generally start in the center of the         tumor and initially "bivalve" it by vaporizing a wide swath         down the middle, to about the level of the endomyometrial junction         (Figure 2). If the resulting pieces are small enough to extract, the         resectoscope is removed and an ovum forceps or a myoma grasper is         inserted. The myoma is firmly grasped, avulsing the remaining portion         with a gentle, twisting motion. Large pieces are further morcellated and         then extracted. The resectoscope is reinserted and, using either the         VaporTrode or a wire loop electrode (remember to lower the wattage to         about 110W pure cut current for the wire loop), the remaining         intracavitary portions of the tumors and/or their stalks are shaved or         vaporized. Bleeding points are coagulated with either electrode, using         about 60W to 70W of a damped or coagulating waveform.

Because of the small, but not         insignificant, risk of unknowingly vaporizing malignant tissue, a         portion of the polyp or myoma must always be removed and sent for         pathologic examination. In our series of over 700 myoma resections, we         have had two patients with unsuspected leiomyosarcoma.

Another critical point to remember is         that once a specimen is severed from its uterine attachment, the energy         pathway to the return electrode (or "ground plate") is lost,         making further electrical morcellation or vaporization of the detached         tissue almost impossible.

For polyps small enough to be extracted         through a dilated cervical canal, it is only necessary to vaporize the         base or stalk and then extract the polyp with an ovum forceps or a myoma         grasper. Larger polyps and submucous myomas are treated similarly.

To avoid the risk of destroying         unsuspected atypical endometrium, even when preoperative sampling was         negative, I usually biopsy the endometrium for pathologic exam at the         beginning of every VaporTrode endometrial ablation. First, using a wire         loop electrode and about 100W of pure cut current, several strips of         endomyometrium are shaved from the posterior surface and then the         anterior surface. These strips are removed for pathologic examination,         leaving furrows of about 4 mm deep to be used as guides to         determine the depth of vaporization. The wire loop is replaced with a         VaporTrode, and using 160W to 200W of pure cut current, the         endomyometrium is sequentially vaporized, leaving the cornual areas         for last, until all viable appearing tissue is vaporized and         dessicated (Figure 3). For the thinner cornual areas, the current         is reduced to 80W or 90W and the surface is desiccated only, rather than         vaporized.

It should be obvious that the         procedure is made easier and more effective if the endometrium         is thinned. Our preference is the use of a GNRH analogue, such as         leuprolide acetate-depot, one month prior to the procedure, although         scheduling during the proliferative phase of a cycle (i.e., days 4 to         7), or using a thorough curettage prior to the procedure has been         reported almost as effective. Preoperative preparation with danazol, usp         is also very effective to thin the endometrium, but the use of         progestins has been disappointing.

From December 1994 through December         1996, I used the VaporTrode for myomectomy in 42 patients with         complaints of menorrhagia due to submucous myomas. To date there have         been no failures, no complications, and no need for further treatment.         The estimated blood loss was under 100 ml in 41 cases and 250 ml in the         other. In no case was there a fluid discrepancy (intravasation) of         greater than 300 ml.

From April 1995 through December 1996,         the VaporTrode was used to perform endometrial vaporization ablation in         place of standard ablation in 19 patients. In all 19 patients the         estimated blood loss was less than 50 ml and fluid discrepancy was less         than 100 ml. Fifteen of the 19 patients have amenorrhea and the other 4         have hypomenorrhea.

It is too soon to say with                 confidence if this technique has better long-term results than                 standard ablation methods, but preliminary results are very                 promising. However, once trained in this method (sidebar), a                 skilled hystero-scopist will soon realize the evident advantages                 in terms of therapeutic efficacy, reduced operative time, and                 increased safety (less bleeding and less intravasation).

Recommendations                         for Maximizing the Efficiency of Electrovaporization

Dr. Brooks is a clinical professor,         department of obstetrics and gynecology, UCLA School of Medicine, and         attending physician, department of obstetrics and gynecology,         Cedars-Sinai Medical Center, Los Angeles, CA.

Articles

For the gynecologist, the introduction of the resectoscope revolutionized the management of submucous myomata that cause uncontrollable uterine bleeding, infertility and pregnancy wastage, and the con-servative control of persistent and excessive uterine bleeding unrelated to uterine filling defects.

The Use of VaperTrode® Vaporization Electrode in Operative Hysteroscopy

To evaluate a new resectoscopic electrode design intended 	to vaporize large intrauterine myomate.

 To study the vaporizing electrode’s capabilities 	of destroying myomata on contact using electrical energy (cutting waveform), attempts were made to find the lowest 	effective power to accomplish the desired effect. Vaporization of myomata was performed in the outpatient surgical 	center of Cedars-Sinai Medical center during operative hysteroscopy, with the patient under general anesthesia. 	The procedures were performed on 12 patients presenting with menorrhagia for what intracavitary submucous myomata 	were discovered at office hysteroscopy, with attempts at settings of from 110-200 W/

 Vaporization of myomata readily occurred, with 200 W 	of pure cutting waveform current the optimal setting.

 A new grooved ball or grooved cylinder electrode 	can be used to vaporize portions of intrauterine myomata to facilitate their removal. Advantages of using the vaporizing 	electrode include significant reduction in the time of the procedure, avoidance of a large number of "chips" 	of myomata that interfere with the case and safety of the resectoscopic procedure, apparently reduced intraoperative 	bleeding and intravascular intravasation. 

Hysteroscopic management of abnormal uterine bleeding has become an important and request gynecologic 	procedure.

When submucous myomata are discovered as the 	etiology of such bleeding, removal of the tumors can be accomplished with the use of the gynecologic resectoscope 	and electrodes (usually wire loop, cutting electrodes) to morcellate the lesions for removal through the cervix.

 While the procedure is quite successful at removing the tumors, it is often 	tedious owing to the production of numerous "chip" of tissue that need to be removed when they obscure 	the view and that make placement of the loop electrode more difficult and dangerous. In addition, resection into 	the tumors often opens large vessels, resulting in bleeding and/or intravasation of sodium-free dissension fluid.

In recent years the development of a corrugated electrode, the VaporTrode (CIRCON ACMI, Stanford, 	Connecticut) has been reported in the urologic literature to have the capacity of vaporizing the prostate in cases 	of prostatic hypertrophy, with dramatic reductions in bleeding, intravasation, duration of surgery and length of 	time requiring indwelling catheterization.

In those procedures, 	vaporization of the prostate was produced using this electrode with up to 300 W of current in a pure cut waveform.

Because of the success of the technique for prostatic surgery, the procedure and instrumentation 	were used in an attempt to vaporize submucous myomata. This paper reports the initial experience for this indication.

From January 1994 through April 1995, 12 patients with a complaint of menorrhagia underwent office 	hysteroscopy, with the finding of submucous myomata that were almost totally intracavitary and measured from 3 	to 5 cm in diameter (confirmed by ultrasonic measurements). All patients were then scheduled for resectoscopic 	surgery at Cedars-Sinai Medical Center, and the surgery was performed as an outpatient procedure under general 	anesthesia without endotracheal intubation. All patients were given single intravenous doses of broad-spectrum 	antibiotics (cefotetan, 2g) just prior to surgery. Uterine distension was effected using 3% solution, and the resectoscope 	used was a standard, continuous-flow, 25 F gynecologic resectoscope with a 12° telescope (CIRCON ACMI). Vaporization 	was performed using a grooved ball electrode, 2.5 mm in diameter, and a grooved cylinder electrode, 3.0 mm in width 	(Figure 1). Blood loss was estimated by the amount of discoloration of the effluent liquid collected in the outflow 	suction bottles, and the discrepancy between inflow volume and outflow volume recorded.

Vaporization of myomata did not occur until the current reached 140 W, and then it was slow and 	minimally deep until 200 W was reached. The wider vaporizing electrode (3.0-mm cylinder) produced a wider path 	of vaporization (Figure 2), while the grooved ball electrode (2.5mm) was more precise in incising portions of the 	myomate (Figure 3). In no case were these chips floating in the endometrial cavity, obscuring the view and requiring 	a halt to the vaporization in order to remove the loose pieces. The resectoscope was withdrawn from the uterine 	cavity only to change electrodes or to inert a ring or myoma-grasping forceps (Figure 4) to remove the remaining 	portions of the morcellated tumor. When a small portion of the myoma remained in the superficial myometrium, the 	wire loop electrode was pure cutting current at 110 W was used to shave the residual tumor (Figure 5). Because 	of the lack of chips, the procedures all were significantly faster than with the gynecologic resectoscope and loop 	electrodes alone.

Fluids in the suction bottles were minimally blood tinged, and all cases were reported as demonstrating 	estimated blood loss of < 110 mL. The discrepancy between inflow and outflow volumes ranged from zero to 200 	mL. In no case was there a significant amount of intravasation of distension fluid.

The most frequent problems arising from the hysteroscopic resection of submucous myomata have 	been blood loss during the procedure, the risk of fluid overload of sodium-free liquids resulting from intravasation 	of these distension fluids, and the tedious job of stopping the resection numerous times to remove vision-obstruction 	pieces of the myoma shaved loose by cutting electrodes.

The vaporizing electrode is grooved to utilize the concept of "edge density": the highest 	concentration of power in an electrode in at the edges. Thus, for example, the three grooves in the vaporizing 	cylinder provide eight edges through which the current is concentrated to vaporize the cells with which it comes 	in contact. The bubbles and heat created by vaporization of living cells are readily removed in a continuous-flow 	system by lower pressure suction on the tubing connected to the outflow port. The use of the vaporizing electrode 	with high current, as opposed to using a cutting loop electrode, apparently induces greater sealing off of blood 	vessels, resulting in less introperative bleeding and intravasaton of distension fluids.

two patients were 	found to have leiomyoscarcoma on pathologic examination of the portions of myomata resected hysteroscopically. 	In neither case was sarcoma suspected from the gross appearance of the lesions. It is mandatory that no myoma be 	vaporized in its entirety but that substantial portions be retrieved for microscopic examination. Actually, it 	is faster to use the vaporizing electrode to divide the myoma into large chunks rather than vaporizing the entire 	tumor. In addition, the speed of performing the procedure is greatly increased as a result of the vaporization 	of large segments, leaving no chips to interfere with the view and no need to withdraw the resectoscope until the 	end of the procedure to remove the pieces with forceps.

Although the follow-up period at present is too short for complete confidence in the long-term 	control of abnormal bleeding, none of the 12 patients thru far have had recurrence of the problem or have required 	further treatment of any type for it.

As it appears to have done in urology for the prostate, the vaporizing electrode, in combination 	with higher settings of cutting current, offers a great advantage in the management of submucous myomata. Vaporizing 	large portions of a myoma results in greater speed, fewer pieces to remove-especially less removal of chips in 	order to see better-and reduced risks of intraoperative bleeding and     intravasation.

A summary of important points in vaporizing submucous myomas is listed in Figure 6. Because of the 	risk of missing leiomyoscarcoma, no myoma should ever be vaporized totally, but portions should be sent for pathologic 	examination. Another risk is the very dangerous use of high current settings, a factor that could increase the 	risk of serious bowel or bladder injury should perforation of the uterus occur. As with other high-technology innovations, 	use of the vaporizing electrode should be limited to surgeons with experience in operative     hysteroscopy.

        1. Neuwirth RS, Amin HK; Excision of submucous fibroids with hysteroscopic control. Am J Obstet Gynecol 1976:126:95-99

        2. Brooks PG, Loffer RD, Serden SP: Resectoscopic removal of symptomatic lesions. J Reprod Med 1989;34:435-437

        3. Valle RD: Hysteroscopic removal of submucous leiomyomas. J Gynecol Surg 1990;6:89-86

        4. Corson S, Brooks PF: Resectoscopic myomectomy. Fertial Steril 1991;55:1041-1044

        5. Babayan RK, Siroky MB, Krane RJ: Transurethral vaporization of the prostate (TUVP): An electrosurgical alternative to laser prostatectomy. Presented at the 12th World Congress on Endourology, St. Louis, Missouri, December 3-6, 1994. 

       6. Bush IM, Malters E, Bush J: Transurethral vaporization of the prostate (TVP): New horizons. Soc Minimally Invasive Ther (suppl) 1993;2:98 

       7. Kaplan SA, Te AE: Transurethral electroevaporaton of the prostate (TVP): A novel method for treating men with benign prostatic hyperplasia. Urology 1995;45:566-572 

    From the Departments of Obstetrics and Gynecology, University of California at Los Angeles School of Medicine and Cedars-Sinai Medical Center, Los Angeles, California.

    Dr. Brooks is Clinical Professor, Department of Obstetrics and Gynecology, University of California at Los Angeles School of Medicine, and Attending Physician, Department of Obstetrics and Gynecology, Cedars-Sinai medical Center, Los Angeles, California.

    Address reprint requests to: Phillip G. Brooks, M.D., 8631 West Third Street, Suite 510E, Los Angeles, CA 90048.

OBJECTIVE: To evaluate a new resectoscopic electrode design intended to vaporize large intrauterine myomate.

Phillip G. Brooks, MD

Articles

The Use of VaperTrode® Vaporization Electrode in Operative Hysteroscopy

Resectoscopic Myoma Vaporizer