Symposium on Gynecologic Cancer
Laser Surgery in Gynecology Helmut F. Schellhas, M.D., F.A.C.o.G.*
The carbon dioxide laser has been applied in gynecologic surgery by the utilization of two different operating mechanisms. One model is adjusted to the optical system of a colposcope, which is a specially designed operating microscope through which the laser beam can be used to destroy microscopic lesions with high precision in the female genital tract (Fig. 1). Directed through theinteriormirrorsystemofamulti:articulated surgical arm in the other model (Sharplan laser), the focused laser beam can be used as a thermal scalpel to perform surgical procedures (Figs. 2 and 3). Several medical centers are presently evaluating the unique properties of the carbon dioxide laser beam for surgical application in gynecology. Although the first results are preliminary, very interesting surgical indications are emanating.
TISSUE EFFECTS OF THE CARBON DIOXIDE LASER The carbon dioxide laser beam is uniformly absorbed by human tissues due to its wave length of 10.6 /Lm, which is in the invisible far infrared region of the electromagnetic spectrum. Since human tissues are poor conductors of thermal energy, thermally induced tissue damage can, therefore, be limited to a very narrow zone when exposure is brief. There is no selective absorption by tissues with different pigmentation as there is with some other types oflasers that operate in the visible range of the electromagnetic spectrum at a shorter wave length. The coherent monochromatic light beam can be precisely focused to a spot ofless than 1 mm in size through an optical lens system. The intense heat of the focused laser beam vaporizes a localized area by boiling the tissue fluid. Heat conduction causes further tissue damage that on histopathologic sections appears as a necrotic zone. The "thermal behavior" of the carbon dioxide laser beam is different for various tissues. 1S According to Ben-Bassat and associates, most sensitive were epithelial cells, showing a necrotic zone of 200 to 250 /Lm in electron microscopic studies while desmosomes, cell nuclei, collagen *Associate Professor of Obstetrics and Gynecology, and Radiation Oncology; Director, Division of Gynecologic Oncology, College of Medicine, University of Cincinnati, Cincinnati, Ohio. Surgical Clinics of North America-Vol. 58, No.1, February 1978
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Figure 1. A compact and maneuverable CO.laser attached to a colposcope and connected to a control console. (Courtesy of Coherent Radiation, Palo Alto, California.)
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Figure 2. The Sharplan laser has an articulated arm used to direct the CO. laser beam through an interior mirror system. The articulated arm can be covered with a sterile plastic sleeve and used in major surgery.
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Figure 3. The endpiece of the Sharplan laser contains a lens that focuses the beam into a point with high energy density. It is used as a thermal scalpel by continuous tissue vaporization. (From Schellhas, H.F. et al.: Resecting vulvar lesions with the CO. laser. Contemp. Db. Gyn., 6:35-39, 1975.)
fibers, and erythrocytes were found structurally preserved 30 to 50 ILm away from the thermal cut. Capillaries of dermal and subepithelial tissue revealed swollen endothelial cells, causing marked narrowing of the lumen at an average distance of 200 to 250 ILm. 2 The depth of tissue penetration is approximately 200 ILm for the carbon dioxide laser beam. The continuous wave of the C0 2 laser can be used to create an incision with the focused beam. The small zone of coagulation necrosis provides a relatively bloodless wound since capillaries and small vessels are sealed. Short time exposures of the laser beam are used for the destruction of lesions of small microscopic dimensions. Although the surgical margins have a small nonviable zone, healing has not been a problem in soft tissues and especially mucosa.
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ENDOSCOPIC LASER SURGERY ON THE CERVIX UTERI The subtle method of selectively destroying a well delineated neoplastic epithelial lesion under direct vision by a well controlled high energy light beam with pinpoint precision is intriguing to the colposcopist, whose major clinical interest is the evaluation of the cervix uteri. Lesions of microscopic dimensions such as carcinoma in situ and dysplasia are frequently detected with routine cytologic screening and are often found in women who desire to preserve their child-bearing capacity. Historically, the local excision of a circumscribed lesion by a cervical conization has been found satisfactory as definitive treatment in many patients of this group. The cervical cone specimen removes the epithelial tissue at risk, which is located at the junctional border between the squamous epithelium of the ectocervix and the columnar epithelium of the endocervix. This area is rather wide, with dynamic proliferation of metaplastic squamous epithelium that the colposcopist terms the "transformation zone" (Fig. 4). During the reproductive years the transformation zone can usually be well outlined by the colposcopist, whereas during the menopausal years this zone moves higher up into the endocervix and cannot be visualized (Fig. 5). With the achievement of high diagnostic accuracy by well experienced colposcopists utilizing cytologic studies and colposcopically directed biopsies to rule out invasive disease, thermal destruction by electrocautery or cryosurgery of well delineated epithelial neoplastic lesions was performed with acceptable results in short term clinical follow-ups. The entire transformation zone is usually destroyed and the depth of tissue destruction can be extended to the base ofthe endocervical glands in a depth of approximately 5 mm. The advantage of thermal tissue
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": Figure 4. Cervix uteri. The transformation zone is identified through the colposcope at the border between the ectocervical sqUaIllOUS epithelium and endocervical colunmar epithelium. Immature squamous epithelium is intermixed with columnar epithelium. This zone is at risk for the development of epithelial neoplasia and has to be completely outlined optically if thermal surgery is applied.
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Figure 5. Cervix uteri. During the reproductive years the transformation zone can usually be outlined on the ectocervix and microscopic lesions can be thermally destroyed. In the postmenopausal years the transformation zone is mostly found within the endocervix and cannot be optically evaluated.
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destruction is that it can be performed as an outpatient procedure. The definite disadvantage is the lack of a histopathologic diagnostic evaluation of the entire lesion treated, which in the hands of inexperienced clinicians can lead to the masking of an invasive carcinoma and disastrous results. In patients whose transformation zone cannot be accurately outlined colposcopically, thermal tissue destruction is contraindicated. The selective, precise destruction of an epithelial lesion by the CO 2 laser beam preserves the surrounding cervical tissue and accomplishes prompt healing. Since the treated tissue is immediately vaporized and the zone of tissue coagulation is very small, it is possible to avoid the tissue slough that follows electrocautery and cryosurgery and causes prolonged and profuse vaginal discharge and sometimes bleeding. The extensive epithelial tissue repair following electrocautery and cryosurgery also replaces the transformation zone high into the cervical canal so that follow-up colposcopic examinations cannot evaluate this critical zone. After limited CO 2 laser tissue destruction the transformation zone is preserved, which is an important advantage. 12. 17 Stafl and associates treated 50 patients with cervical and vaginal neoplasia with the carbon dioxide laser beam through the colposcope. 12 Anesthesia was not found to be necessary. Treatment failure occurred in 10 per cent ofthe patients, which is compatible with the results of other thermal methods. All abnormal cytology was picked up during the first three months follow-up examination. Long term treatment results are not yet available. Stafl did not feel that the CO 2 laser treatment was measurably superior to the other conservative methods available for the treatment of cervical neoplasia.
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Kaplan and associates 5 treated "cervical erosions" with the CO 2 laser without the use of anesthesia and found the rapidity of healing and the absence of vaginal discharge advantageous. Laser conization was attempted by Toaff.16 He encountered abundant bleeding when the procedure was performed in the edematous tissue of the chronically inflamed cervix. The Sharplan laser was also found to be too unwieldy for the proper cutting angles required for cervical conizaton.
VAGINAL LASER SURGERY Most advantageous was the endoscopic carbon dioxide laser beam in the treatment of vaginal lesions, as StafL and associates reported. 12 The depth of tissue vaporization can be controlled and injury to bladder and rectum avoided. In addition, it appears that the vaginal mucosa heals without mutilating scar formation following laser destruction. This important property of CO 2 laser surgery on mucosal membranes was first reported by Strong and Jako with their experience in vocal cord surgery. 15 The vaginal lesions treated by StafL and associates were dysplasia (three cases) and carcinoma in situ (three cases). We found the Sharplanlaser·to be useful in three cases of vaginal carcinoma in situ, one of which was recurrent after hysterectomy, but believe that a colposcopically directed beam is more controlled. The presence of invasive carcinoma has to be ruled out before local treatment is initiated. The laser colposcope became available at a time when vaginal adenosis turned out to be a clinical problem in adolescent girls who were exposed to synthetic estrogens during fetal development. Squamous epithelial abnormalities are relatively frequently found on colposcopic examination. 13 At the present time, however, the natural history of benign vaginal adenosis does not appear to have a high risk for the development of adenocarcinomas or squamous carcinomas. For this reason, the clinical management is mostly expectant. StafL restricted CO 2 laser treatment to two patients with benign vaginal adenosis who were clinically symtomatic with dyspareunia and significant vaginal discharge. 12 It is believed that the application of the CO 2 laser in the treatment of vaginal lesions is superior to other thermal methods such as electrosurgery and cryosurgery, and also to excision with the knife. 1 • 12 The lack ofameans of histopathologic examination of the entire lesion, however, requires thorough and expert presurgical cytologic and colposcopic evaluation, as well as the obtaining of representative tissue biopsy specimens.
INCISIONAL CARBON DIOXIDE LASER SURGERY The vaporizing effect of a continuous wave CO 2 laser beam delivered through the surgical arm of the Sharplan laser can be used to cut and dissect tissue thermally. Good tension of the tissue to be incised is important. Small vessels and capillaries are coagulated during the incision. The surgical field must be dry; otherwise, the laser beam will be completely
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absorbed by the blood. The irradiance (power/unit/area) of the beam can be regulated according to the surgeon's need. The Sharplan laser that we use operates over a range of 1 0 to 50 watts. Our incisional technique employs an average of25 watts. Since the depth of the initial incision does not extend to more than 200 /Lm, repeat focused vaporization along the incisionalline is necessary. The base of the incision develops a superficially charred layer that subsequently stops the laser beam. Continued lasing would thermally damage the underlying tissue without the desired vaporization effect. For that reason immediate debridement by a quick wipe with a moist sponge is done and this is followed by another wipe with a dry sponge; otherwise the moisture would partially absorb the laser beam. Small vessels up to a size of 0.5 mm are usually controlled when the blood flow has been compressed. Small bleeders can mostly be stopped by coagulation with the unfocused laser beam. The area to be coagulated, however, must be dry; ifnot, the covering blood absorbs the laser beam. Most bleeding vessels, nevertheless, should be conventionally clamped with a hemostat and ligated. The laser-purist directs the unfocused laser beam to the tissue next to the tip of the clamp for hemostasis, which in our experience is mostly ineffective. Coagulation of tissue by heating the tip of the clamp with an unfocused beam is a questionable technique. The beam will reflect from the surface of the metal and the instrument itself may be damaged. Moist gauze should shield the margins of the surgical field. The fumes produced during surgery are removed by a vacuum pump (Fig. 6). In addition to the relatively hemostatic effect of the CO 2 laser, it has been
Figure 6. The Sharplan laser is used to excise a giant condyloma acuminatum. Moist gauze shields the margins of the surgical field; a vacuum pump is poised to remove tissue fumes. (From Schellhas, H. F., et al.: Resecting vulvar lesions with the CO 2 laser. Contemp. Ob. Gyn., 6:35-39, 1975.) .
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shown that a CO 2 laser excised wound bed accepts skin autografts readily. Infected areas (such as in decubitus ulcers) can be excised or vaporized, and resulting wound sterility has been reported. 14
VULVAR LASER SURGERY With the CO 2 laser scalpel (Sharplan laser) we resected three giant condyloma acuminata in pregnant patients (Fig. 7A-C) and one giant condyloma acuminatum associated with a type of isoimmune anemia. There was minimal blood loss during surgery and the healing was uneventfu1. 9 • 10 No recurrence occurred in two to four years follow-up. Several more patients with condylomas were treated by laser excision or just by
Figure 7. A, Giant condyloma acuminatum in pregnancy before laser scalpel excision. B, After laser scalpel excision. C, Vulva appearance six weeks postoperatively. (From Schellhas, H. F. et al.: Resecting vulvar lesions with the CO, laser. Contemp. Ob. Gyn.,6:35-39, 1975.)
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Figure 8. A, Perianal condyloma acuminatum involving external sphincter muscle. B, The lesion is resected with the laser scalpel, including external sphincter muscle. C, Anus, six weeks later. (Courtesy of Dr. J. P. Fidler, Department of Surgery, University of Cincinnati Medical Center, Cincinnati, Ohio.)
c vaporizing the condylomas down to the base. The fact that this viral tissue actually is not touched during surgery is intriguing and might have clinical significance. The c0 2 1aserwas helpful in the resection or vaporization of perianal and periurethral and meatal condylomas (Figs. 8 and 9). We also performed a radical vulvectomy on a high risk patient in whom the blood loss had to be kept minimal. The surgical time was extended, and we did not see any advantage over the electrosurgical scalpel. Preparation of the skin flap during groin dissection with the CO 2 laser in another patient also consumed much time and, although the estimated blood loss was considerably less than that on the opposite side (which was dissected with a sharp scalpel), it was of no clinical significance.
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Figure 9. Periurethral and intraIlleatal condylomata acuminata. After vaporization with the C0 2 laser no scar formation developed and the patient remained free of recurrence during her one year follow-up.
The resection of vulvar lesions in pregnant patients with highly vascular tissue by the CO 2 laser scalpel or other extensive surgical procedures in which minimal blood loss is essential yields excellent clinical results. Controlled clinical studies are still required to compare the effects oflaser surgery with electrosurgery or the cold knife. Krantz 7 reported laser ablation of the entire vulvar skin in three cases of lichen sclerosus et atrophicus followed by total relief of the symptoms and progressive rehealing. He believes this to be a significant breakthrough in this area. Molluscum contagiosum of the vulva also responded well in his experience.
TUMOR VOLUME REDUCTION The Sharplan laser appears to be an invaluable tool in the destruction of selective unresectable tumors by tissue vaporization. If complete tumor vaporization is technically impossible, partial volume reduction might render the tumor more favorable to radiation therapy, chemotherapy, or a combination of both. FIRST CASE REPORT
A 36 year old woman was treated by a radical hysterectomy with pelvic node dissection for Stage IB adenocarcinoma of the cervix. Ten months later she re-
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Figure 10. Isolated recurrent tumor (dark field) developed on the posterior ischial spine following previous surgery and radiation therapy. Laser vaporization is at present the best surgical means to remove tumor tissue attached to bones.
ceived radiation therapy to the pelvis for recurrent tumor on the left pelvic sidewall and had clinically a good response. Eleven months following the irradiation, she had again a solitary tumor recurrence to the left pelvic sidewall that enveloped the posterior ischial spine (Fig. 10). On surgical exploration, the tumor did not involve the iliac vessels and could be vaporized with the CO 2 laser beam. The procedure was followed by chemotherapy since the surgical margins could not be completely checked and additional metastatic disease might have been in existence. The patient has remained tumor free for a 12 month follow-up.
SECOND CASE REpORT
A 74 year old woman developed large unilateral groin nodes with metastatic disease secondary to a microinvasive squamous carcinoma of the vulva treated six months earlier by a vulvectomy. The groin lesion continued to enlarge rapidly while treated with external radiation therapy (Fig. 11A). The groin tumor was vaporized to the level of the skin and remained controlled for six months (Fig. lIB). The patient expired one month later of undetermined cause. THIRD CASE REPORT
A benign clinical appearance was found in one patient with a symptomatic retroperitoneal endometrioma located lateral to the bladder, close to the pelvic wall. Following surgical exposure and biopsy for a frozen section examination, the lesion was vaporized with the Sharplan laser and the patient remained free of symptoms.
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Figure 11. A, Metastatic groin lesion rapidly enlarging during radiation therapy. B, Tumor volume reduced by CO. laser vaporization. (Photographed two weeks after surgery.) (From Schellhas, H. F.: Laser application in gynecologic oncology. In Aronoff, B. L., et al.: International Advances in Surgical Oncology, in press, with permission.) COMMENT
We prefer to perform exploratory surgery for recurrent pelvic tumors with the Sharplan laser on hand. The CO 2 laser can vaporize bony tissue
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and, for that reason, might help to control tumor attached to bony structures. The recurrence of pelvic tumors surrounding the large iliac vessels, however, cannot yet be safely vaporized with the CO 2 laser. Also, diffuse tumor metastases involving the serosa of visceral structures cannot be well treated. For most recurrent tumors, therefore, the CO 2 laser is of little help. Special tumor cell staining methods such as immunofluorescence and the application of selective wave length coherent light that would be absorbed by tumor cells only are future goals in laser cancer surgery.
ABDOMINAL LASER SURGERY In abdominal operations, the abilities of the carbon dioxide laser to seal capillaries and small vessels without significant devitalized surgical margins was applied by Toaffin conservative myomectomies and reconstructive surgery of the tubes. 16 Using the Sharplan laser he found the operations practically bloodless. Of four patients who underwent myomectomies, one developed an infected hematoma. Eight patients had lysis of periadnexal adhesions performed. Postoperative hysterosalpingograms oflaparoscopic evaluations in four patients were found satisfactory. Follow-up was too short in regard to fertility results. Toaff emphasizes utmost precision for the manipulation of the laser beam in order not to inadvertently damage adjacent organs. We performed retroperitoneal tumor vaporization through an abdominal approach in two patients.
LAPAROSCOPY Since most gynecologists are proficient laparoscopists, the role of the laser in this field today is ofinterest. The heat of the CO 2 laser beam would destroy conventional fiberoptic bundles, and fiberoptics are not yet available for use with this technique. However, both the argon laser beam and the neodymium-yag laser beam can be transmitted through a quartz rod specially designed by N ath et al. 8 With this fiberoptic laser system attached to an operating laparoscope, N ath and his associates found the surgical properties of the argon laser and later ofthe neodymium-yag laser to be comparable to those of the CO 2 laser in highly vascularized organs of experimental animals. This fiberoptic system has been successfully applied in clinical gastroenterologyB and urology, 11 but not yet in gynecology. SAFETY PRECAUTIONS FOR THE CARBON DIOXIDE LASER The carbon dioxide laser beam is invisible at its wave length of 10.6 /Lm. The cornea absorbs the beam totally and can therefore be severely
damaged. Conventional eyeglasses or plastic goggles stop the beam com-
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pletely and are required for all operating room personnel. Since flammable material can be ignited by the laser beam, wet gauze sponges should shield the margins of the operative field and nonflammable anesthetics should be administered. The beam reflects from metal, but this circumstance can be avoided by cautious surgical technique. (The reflecting beam is, however, usually harmless because it is divergent.) Theoretically, virulent malignant cell material might be contained in the fumes resulting from tumor vaporization. Optimal evacuation of the fumes is suggested. Goldman' has emphasized that there is no evidence for possible direct carcinogenic properties of any laser beams used in medicine today. The powerful CO 2 lasers must be handled with detailed technical knowledge, and the clinical indications for t0 2 laser surgery should be carefully considered. In our institution laser surgery is still regarded as experimental, and a special consent form must be signed by the patients.
LASER INSTRUMENTATION For the functional description of the various carbon dioxide laser models and an introduction to laser radiation physics, the reader is referred to the excellent brief monograph ofVerschueren. J8 The CO 2 lasers available on the market today are unfortunately designed either for endoscopic surgery through an operating microscope or for surgery with an articulated arm. The option to adjust an endoscopic laser to function as a thermal scalpel for major surgery or vice versa is not yet available. The present enormous cost of surgical lasers prohibits the purchase of two different models. In some medical centers, surgical lasers are shared by several departments and are therefore more cost-effective.
SUMMARY More experience and time are required to determine the advantages of laser surgery in gynecology. For precision surgery through the colposcope, the carbon dioxide laser beam appears to be useful in the control of neoplastic lesions of the vaginal mucosa and possibly of the cervix uter.i. Tumor volume reduction through laser vaporization, especially when a recurrent tumor is attached to the bony pelvis, is an outstanding advantage. Adhesiolysis during myomectomy and reconstructive surgery of the fallopian tubes migh be facilitated by the laser beam. Laser surgery on the vulva, both colposcopically directed and grossly with the CO 2 laser scalpel, might prove to be important for the treatment of various lesions. Detailed technical knowledge, rigid safety precautions, and judicious clinical considerations are essential for competent laser surgery.
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ACKNOWLEDGMENT
The author wishes to acknowledge the support received for laser surgery by the Marx Foundation and the Morgan Pennington Memorial Fund.
REFERENCES 1. Bellina, J. H.: Gynecology and the laser. Contemp. Ob. Gyn., 4:24-34, 1974. 2. Ben-Bassat, M., Ben-Bassat, M., and Kaplan, I.: An ultrastructural study of the cut edges of skin and mucous membrane specimens excised by carbon dioxide laser. In Kaplan, I. (Editor): Laser Surgery. Jerusalem, Jerusalem Academic Press, 1976, 95-100. 3. Fidler, J. P., Law, E., Rockwell, R. J., et al.: Carbon dioxide laser excision of acute burns with immediate autografting. J. Surg. Res., 17:1-11,1974. 4. Goldman, L., Rockwell, R. J., Fidler, J. P., et al.: Investigative laser surgery: safety aspects. Biomed. Eng., 4:415-418, 1969. 5. Kaplan, I., Goldman, J., and Ger, R.: The treatment of erosions of the uterine cervix by means of the CO 2 laser. Obstet. Gynecol., 41 :795-796, 1973. 6. Kiefhaber, P., N ath, G., and Moritz, K: Endoscopical control of massive gastrointestinal hemorrhage by irradiation with a high-power neodymium-yag laser. Prog. Surg., 15:140-155,1977. 7. Krantz, K: (Discussion) Laser treatment of cervical and vaginal neoplasia. Am. J. Obstet. GynecoL, 128:135, 1977. 8. Nath, G., Gorisch, W., and Kiefkaber, P.: First laser endoscopy via a fiberoptic transmission system. Endoscopy, 5:208-213, 1973. 9. Schellhas, H. F., Fidler, J. P., and Rockwell, R. J.: The carbon dioxide laser scalpel in the management of vulvar lesions. In Kaplan, I. (Editor): Laser Surgery Jerusalem, Jerusalem Academic Press, 1976,33-135. 10. Schellhas, H. F., Fidler, J. P., Rockwell, R."J., et al.: Resecting vulvar lesions with the CO 2 laser. Contemp. Ob. Gyn., 6:35-39, 1975. 11. Staehler, V. G., Hofstetter, A., Schiedt, E., et al.: Endoskopische Laser-Bestrahlung von Blasentumoren des Menschen. Fortschr. Med., 95:3-7,1977. 12. Stafl, A., Wilkinson, E. J., and Mattingly, R. F.: Laser treatment of cervical and vaginal neoplasia. Am. J. Obstet. Gynecol., 128:128-136, 1977. 13. Stafl, A., and Mattingly, R. F.: Vaginal adenosis: a precancerous lesion? Am. J. Obstet. GynecoL, 120:666-667, 1974. 14. Stellar, S., Meijer, R., Walia, S., et al.: Carbon dioxide laser debridement of decubitus ulcers. Ann. Surg., 179:230-237,1974. 15. Strong, M. S., and Jako, G.J.: Laser surgery in the larynx. Ann. Otol., 81 :791-798,1972. 16. Toaff, R.: The carbon dioxide laser in gynecological surgery. In Kaplan, I. (Editor): Laser Surgery Jerusalem, Jerusalem Academic Press, 1972, 129-132. 17. Upton, R.: (Discussion) Laser treatment of cervical and vaginal neoplasia. Am. J. Obstet. GynecoL, 128:134, 1977. 18. Verschueren, R.: The CO 2 Laser in Tumor Surgery. AssenlAmsterdam, Van Gorcum, 1976. Department of Obstetrics and Gynecology University of Cincinnati Medical Center 231 Bethesda Avenue Cincinnati, Ohio 45267
\
Laser Surgery in Gynecology Helmut F. Schellhas, M.D., F.A.C.o.G.*
The carbon dioxide laser has been applied in gynecologic surgery by the utilization of two different operating mechanisms. One model is adjusted to the optical system of a colposcope, which is a specially designed operating microscope through which the laser beam can be used to destroy microscopic lesions with high precision in the female genital tract (Fig. 1). Directed through theinteriormirrorsystemofamulti:articulated surgical arm in the other model (Sharplan laser), the focused laser beam can be used as a thermal scalpel to perform surgical procedures (Figs. 2 and 3). Several medical centers are presently evaluating the unique properties of the carbon dioxide laser beam for surgical application in gynecology. Although the first results are preliminary, very interesting surgical indications are emanating.
TISSUE EFFECTS OF THE CARBON DIOXIDE LASER The carbon dioxide laser beam is uniformly absorbed by human tissues due to its wave length of 10.6 /Lm, which is in the invisible far infrared region of the electromagnetic spectrum. Since human tissues are poor conductors of thermal energy, thermally induced tissue damage can, therefore, be limited to a very narrow zone when exposure is brief. There is no selective absorption by tissues with different pigmentation as there is with some other types oflasers that operate in the visible range of the electromagnetic spectrum at a shorter wave length. The coherent monochromatic light beam can be precisely focused to a spot ofless than 1 mm in size through an optical lens system. The intense heat of the focused laser beam vaporizes a localized area by boiling the tissue fluid. Heat conduction causes further tissue damage that on histopathologic sections appears as a necrotic zone. The "thermal behavior" of the carbon dioxide laser beam is different for various tissues. 1S According to Ben-Bassat and associates, most sensitive were epithelial cells, showing a necrotic zone of 200 to 250 /Lm in electron microscopic studies while desmosomes, cell nuclei, collagen *Associate Professor of Obstetrics and Gynecology, and Radiation Oncology; Director, Division of Gynecologic Oncology, College of Medicine, University of Cincinnati, Cincinnati, Ohio. Surgical Clinics of North America-Vol. 58, No.1, February 1978
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Figure 1. A compact and maneuverable CO.laser attached to a colposcope and connected to a control console. (Courtesy of Coherent Radiation, Palo Alto, California.)
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Figure 2. The Sharplan laser has an articulated arm used to direct the CO. laser beam through an interior mirror system. The articulated arm can be covered with a sterile plastic sleeve and used in major surgery.
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Figure 3. The endpiece of the Sharplan laser contains a lens that focuses the beam into a point with high energy density. It is used as a thermal scalpel by continuous tissue vaporization. (From Schellhas, H.F. et al.: Resecting vulvar lesions with the CO. laser. Contemp. Db. Gyn., 6:35-39, 1975.)
fibers, and erythrocytes were found structurally preserved 30 to 50 ILm away from the thermal cut. Capillaries of dermal and subepithelial tissue revealed swollen endothelial cells, causing marked narrowing of the lumen at an average distance of 200 to 250 ILm. 2 The depth of tissue penetration is approximately 200 ILm for the carbon dioxide laser beam. The continuous wave of the C0 2 laser can be used to create an incision with the focused beam. The small zone of coagulation necrosis provides a relatively bloodless wound since capillaries and small vessels are sealed. Short time exposures of the laser beam are used for the destruction of lesions of small microscopic dimensions. Although the surgical margins have a small nonviable zone, healing has not been a problem in soft tissues and especially mucosa.
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ENDOSCOPIC LASER SURGERY ON THE CERVIX UTERI The subtle method of selectively destroying a well delineated neoplastic epithelial lesion under direct vision by a well controlled high energy light beam with pinpoint precision is intriguing to the colposcopist, whose major clinical interest is the evaluation of the cervix uteri. Lesions of microscopic dimensions such as carcinoma in situ and dysplasia are frequently detected with routine cytologic screening and are often found in women who desire to preserve their child-bearing capacity. Historically, the local excision of a circumscribed lesion by a cervical conization has been found satisfactory as definitive treatment in many patients of this group. The cervical cone specimen removes the epithelial tissue at risk, which is located at the junctional border between the squamous epithelium of the ectocervix and the columnar epithelium of the endocervix. This area is rather wide, with dynamic proliferation of metaplastic squamous epithelium that the colposcopist terms the "transformation zone" (Fig. 4). During the reproductive years the transformation zone can usually be well outlined by the colposcopist, whereas during the menopausal years this zone moves higher up into the endocervix and cannot be visualized (Fig. 5). With the achievement of high diagnostic accuracy by well experienced colposcopists utilizing cytologic studies and colposcopically directed biopsies to rule out invasive disease, thermal destruction by electrocautery or cryosurgery of well delineated epithelial neoplastic lesions was performed with acceptable results in short term clinical follow-ups. The entire transformation zone is usually destroyed and the depth of tissue destruction can be extended to the base ofthe endocervical glands in a depth of approximately 5 mm. The advantage of thermal tissue
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": Figure 4. Cervix uteri. The transformation zone is identified through the colposcope at the border between the ectocervical sqUaIllOUS epithelium and endocervical colunmar epithelium. Immature squamous epithelium is intermixed with columnar epithelium. This zone is at risk for the development of epithelial neoplasia and has to be completely outlined optically if thermal surgery is applied.
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Figure 5. Cervix uteri. During the reproductive years the transformation zone can usually be outlined on the ectocervix and microscopic lesions can be thermally destroyed. In the postmenopausal years the transformation zone is mostly found within the endocervix and cannot be optically evaluated.
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destruction is that it can be performed as an outpatient procedure. The definite disadvantage is the lack of a histopathologic diagnostic evaluation of the entire lesion treated, which in the hands of inexperienced clinicians can lead to the masking of an invasive carcinoma and disastrous results. In patients whose transformation zone cannot be accurately outlined colposcopically, thermal tissue destruction is contraindicated. The selective, precise destruction of an epithelial lesion by the CO 2 laser beam preserves the surrounding cervical tissue and accomplishes prompt healing. Since the treated tissue is immediately vaporized and the zone of tissue coagulation is very small, it is possible to avoid the tissue slough that follows electrocautery and cryosurgery and causes prolonged and profuse vaginal discharge and sometimes bleeding. The extensive epithelial tissue repair following electrocautery and cryosurgery also replaces the transformation zone high into the cervical canal so that follow-up colposcopic examinations cannot evaluate this critical zone. After limited CO 2 laser tissue destruction the transformation zone is preserved, which is an important advantage. 12. 17 Stafl and associates treated 50 patients with cervical and vaginal neoplasia with the carbon dioxide laser beam through the colposcope. 12 Anesthesia was not found to be necessary. Treatment failure occurred in 10 per cent ofthe patients, which is compatible with the results of other thermal methods. All abnormal cytology was picked up during the first three months follow-up examination. Long term treatment results are not yet available. Stafl did not feel that the CO 2 laser treatment was measurably superior to the other conservative methods available for the treatment of cervical neoplasia.
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Kaplan and associates 5 treated "cervical erosions" with the CO 2 laser without the use of anesthesia and found the rapidity of healing and the absence of vaginal discharge advantageous. Laser conization was attempted by Toaff.16 He encountered abundant bleeding when the procedure was performed in the edematous tissue of the chronically inflamed cervix. The Sharplan laser was also found to be too unwieldy for the proper cutting angles required for cervical conizaton.
VAGINAL LASER SURGERY Most advantageous was the endoscopic carbon dioxide laser beam in the treatment of vaginal lesions, as StafL and associates reported. 12 The depth of tissue vaporization can be controlled and injury to bladder and rectum avoided. In addition, it appears that the vaginal mucosa heals without mutilating scar formation following laser destruction. This important property of CO 2 laser surgery on mucosal membranes was first reported by Strong and Jako with their experience in vocal cord surgery. 15 The vaginal lesions treated by StafL and associates were dysplasia (three cases) and carcinoma in situ (three cases). We found the Sharplanlaser·to be useful in three cases of vaginal carcinoma in situ, one of which was recurrent after hysterectomy, but believe that a colposcopically directed beam is more controlled. The presence of invasive carcinoma has to be ruled out before local treatment is initiated. The laser colposcope became available at a time when vaginal adenosis turned out to be a clinical problem in adolescent girls who were exposed to synthetic estrogens during fetal development. Squamous epithelial abnormalities are relatively frequently found on colposcopic examination. 13 At the present time, however, the natural history of benign vaginal adenosis does not appear to have a high risk for the development of adenocarcinomas or squamous carcinomas. For this reason, the clinical management is mostly expectant. StafL restricted CO 2 laser treatment to two patients with benign vaginal adenosis who were clinically symtomatic with dyspareunia and significant vaginal discharge. 12 It is believed that the application of the CO 2 laser in the treatment of vaginal lesions is superior to other thermal methods such as electrosurgery and cryosurgery, and also to excision with the knife. 1 • 12 The lack ofameans of histopathologic examination of the entire lesion, however, requires thorough and expert presurgical cytologic and colposcopic evaluation, as well as the obtaining of representative tissue biopsy specimens.
INCISIONAL CARBON DIOXIDE LASER SURGERY The vaporizing effect of a continuous wave CO 2 laser beam delivered through the surgical arm of the Sharplan laser can be used to cut and dissect tissue thermally. Good tension of the tissue to be incised is important. Small vessels and capillaries are coagulated during the incision. The surgical field must be dry; otherwise, the laser beam will be completely
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absorbed by the blood. The irradiance (power/unit/area) of the beam can be regulated according to the surgeon's need. The Sharplan laser that we use operates over a range of 1 0 to 50 watts. Our incisional technique employs an average of25 watts. Since the depth of the initial incision does not extend to more than 200 /Lm, repeat focused vaporization along the incisionalline is necessary. The base of the incision develops a superficially charred layer that subsequently stops the laser beam. Continued lasing would thermally damage the underlying tissue without the desired vaporization effect. For that reason immediate debridement by a quick wipe with a moist sponge is done and this is followed by another wipe with a dry sponge; otherwise the moisture would partially absorb the laser beam. Small vessels up to a size of 0.5 mm are usually controlled when the blood flow has been compressed. Small bleeders can mostly be stopped by coagulation with the unfocused laser beam. The area to be coagulated, however, must be dry; ifnot, the covering blood absorbs the laser beam. Most bleeding vessels, nevertheless, should be conventionally clamped with a hemostat and ligated. The laser-purist directs the unfocused laser beam to the tissue next to the tip of the clamp for hemostasis, which in our experience is mostly ineffective. Coagulation of tissue by heating the tip of the clamp with an unfocused beam is a questionable technique. The beam will reflect from the surface of the metal and the instrument itself may be damaged. Moist gauze should shield the margins of the surgical field. The fumes produced during surgery are removed by a vacuum pump (Fig. 6). In addition to the relatively hemostatic effect of the CO 2 laser, it has been
Figure 6. The Sharplan laser is used to excise a giant condyloma acuminatum. Moist gauze shields the margins of the surgical field; a vacuum pump is poised to remove tissue fumes. (From Schellhas, H. F., et al.: Resecting vulvar lesions with the CO 2 laser. Contemp. Ob. Gyn., 6:35-39, 1975.) .
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shown that a CO 2 laser excised wound bed accepts skin autografts readily. Infected areas (such as in decubitus ulcers) can be excised or vaporized, and resulting wound sterility has been reported. 14
VULVAR LASER SURGERY With the CO 2 laser scalpel (Sharplan laser) we resected three giant condyloma acuminata in pregnant patients (Fig. 7A-C) and one giant condyloma acuminatum associated with a type of isoimmune anemia. There was minimal blood loss during surgery and the healing was uneventfu1. 9 • 10 No recurrence occurred in two to four years follow-up. Several more patients with condylomas were treated by laser excision or just by
Figure 7. A, Giant condyloma acuminatum in pregnancy before laser scalpel excision. B, After laser scalpel excision. C, Vulva appearance six weeks postoperatively. (From Schellhas, H. F. et al.: Resecting vulvar lesions with the CO, laser. Contemp. Ob. Gyn.,6:35-39, 1975.)
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Figure 8. A, Perianal condyloma acuminatum involving external sphincter muscle. B, The lesion is resected with the laser scalpel, including external sphincter muscle. C, Anus, six weeks later. (Courtesy of Dr. J. P. Fidler, Department of Surgery, University of Cincinnati Medical Center, Cincinnati, Ohio.)
c vaporizing the condylomas down to the base. The fact that this viral tissue actually is not touched during surgery is intriguing and might have clinical significance. The c0 2 1aserwas helpful in the resection or vaporization of perianal and periurethral and meatal condylomas (Figs. 8 and 9). We also performed a radical vulvectomy on a high risk patient in whom the blood loss had to be kept minimal. The surgical time was extended, and we did not see any advantage over the electrosurgical scalpel. Preparation of the skin flap during groin dissection with the CO 2 laser in another patient also consumed much time and, although the estimated blood loss was considerably less than that on the opposite side (which was dissected with a sharp scalpel), it was of no clinical significance.
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Figure 9. Periurethral and intraIlleatal condylomata acuminata. After vaporization with the C0 2 laser no scar formation developed and the patient remained free of recurrence during her one year follow-up.
The resection of vulvar lesions in pregnant patients with highly vascular tissue by the CO 2 laser scalpel or other extensive surgical procedures in which minimal blood loss is essential yields excellent clinical results. Controlled clinical studies are still required to compare the effects oflaser surgery with electrosurgery or the cold knife. Krantz 7 reported laser ablation of the entire vulvar skin in three cases of lichen sclerosus et atrophicus followed by total relief of the symptoms and progressive rehealing. He believes this to be a significant breakthrough in this area. Molluscum contagiosum of the vulva also responded well in his experience.
TUMOR VOLUME REDUCTION The Sharplan laser appears to be an invaluable tool in the destruction of selective unresectable tumors by tissue vaporization. If complete tumor vaporization is technically impossible, partial volume reduction might render the tumor more favorable to radiation therapy, chemotherapy, or a combination of both. FIRST CASE REPORT
A 36 year old woman was treated by a radical hysterectomy with pelvic node dissection for Stage IB adenocarcinoma of the cervix. Ten months later she re-
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Figure 10. Isolated recurrent tumor (dark field) developed on the posterior ischial spine following previous surgery and radiation therapy. Laser vaporization is at present the best surgical means to remove tumor tissue attached to bones.
ceived radiation therapy to the pelvis for recurrent tumor on the left pelvic sidewall and had clinically a good response. Eleven months following the irradiation, she had again a solitary tumor recurrence to the left pelvic sidewall that enveloped the posterior ischial spine (Fig. 10). On surgical exploration, the tumor did not involve the iliac vessels and could be vaporized with the CO 2 laser beam. The procedure was followed by chemotherapy since the surgical margins could not be completely checked and additional metastatic disease might have been in existence. The patient has remained tumor free for a 12 month follow-up.
SECOND CASE REpORT
A 74 year old woman developed large unilateral groin nodes with metastatic disease secondary to a microinvasive squamous carcinoma of the vulva treated six months earlier by a vulvectomy. The groin lesion continued to enlarge rapidly while treated with external radiation therapy (Fig. 11A). The groin tumor was vaporized to the level of the skin and remained controlled for six months (Fig. lIB). The patient expired one month later of undetermined cause. THIRD CASE REPORT
A benign clinical appearance was found in one patient with a symptomatic retroperitoneal endometrioma located lateral to the bladder, close to the pelvic wall. Following surgical exposure and biopsy for a frozen section examination, the lesion was vaporized with the Sharplan laser and the patient remained free of symptoms.
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Figure 11. A, Metastatic groin lesion rapidly enlarging during radiation therapy. B, Tumor volume reduced by CO. laser vaporization. (Photographed two weeks after surgery.) (From Schellhas, H. F.: Laser application in gynecologic oncology. In Aronoff, B. L., et al.: International Advances in Surgical Oncology, in press, with permission.) COMMENT
We prefer to perform exploratory surgery for recurrent pelvic tumors with the Sharplan laser on hand. The CO 2 laser can vaporize bony tissue
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and, for that reason, might help to control tumor attached to bony structures. The recurrence of pelvic tumors surrounding the large iliac vessels, however, cannot yet be safely vaporized with the CO 2 laser. Also, diffuse tumor metastases involving the serosa of visceral structures cannot be well treated. For most recurrent tumors, therefore, the CO 2 laser is of little help. Special tumor cell staining methods such as immunofluorescence and the application of selective wave length coherent light that would be absorbed by tumor cells only are future goals in laser cancer surgery.
ABDOMINAL LASER SURGERY In abdominal operations, the abilities of the carbon dioxide laser to seal capillaries and small vessels without significant devitalized surgical margins was applied by Toaffin conservative myomectomies and reconstructive surgery of the tubes. 16 Using the Sharplan laser he found the operations practically bloodless. Of four patients who underwent myomectomies, one developed an infected hematoma. Eight patients had lysis of periadnexal adhesions performed. Postoperative hysterosalpingograms oflaparoscopic evaluations in four patients were found satisfactory. Follow-up was too short in regard to fertility results. Toaff emphasizes utmost precision for the manipulation of the laser beam in order not to inadvertently damage adjacent organs. We performed retroperitoneal tumor vaporization through an abdominal approach in two patients.
LAPAROSCOPY Since most gynecologists are proficient laparoscopists, the role of the laser in this field today is ofinterest. The heat of the CO 2 laser beam would destroy conventional fiberoptic bundles, and fiberoptics are not yet available for use with this technique. However, both the argon laser beam and the neodymium-yag laser beam can be transmitted through a quartz rod specially designed by N ath et al. 8 With this fiberoptic laser system attached to an operating laparoscope, N ath and his associates found the surgical properties of the argon laser and later ofthe neodymium-yag laser to be comparable to those of the CO 2 laser in highly vascularized organs of experimental animals. This fiberoptic system has been successfully applied in clinical gastroenterologyB and urology, 11 but not yet in gynecology. SAFETY PRECAUTIONS FOR THE CARBON DIOXIDE LASER The carbon dioxide laser beam is invisible at its wave length of 10.6 /Lm. The cornea absorbs the beam totally and can therefore be severely
damaged. Conventional eyeglasses or plastic goggles stop the beam com-
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pletely and are required for all operating room personnel. Since flammable material can be ignited by the laser beam, wet gauze sponges should shield the margins of the operative field and nonflammable anesthetics should be administered. The beam reflects from metal, but this circumstance can be avoided by cautious surgical technique. (The reflecting beam is, however, usually harmless because it is divergent.) Theoretically, virulent malignant cell material might be contained in the fumes resulting from tumor vaporization. Optimal evacuation of the fumes is suggested. Goldman' has emphasized that there is no evidence for possible direct carcinogenic properties of any laser beams used in medicine today. The powerful CO 2 lasers must be handled with detailed technical knowledge, and the clinical indications for t0 2 laser surgery should be carefully considered. In our institution laser surgery is still regarded as experimental, and a special consent form must be signed by the patients.
LASER INSTRUMENTATION For the functional description of the various carbon dioxide laser models and an introduction to laser radiation physics, the reader is referred to the excellent brief monograph ofVerschueren. J8 The CO 2 lasers available on the market today are unfortunately designed either for endoscopic surgery through an operating microscope or for surgery with an articulated arm. The option to adjust an endoscopic laser to function as a thermal scalpel for major surgery or vice versa is not yet available. The present enormous cost of surgical lasers prohibits the purchase of two different models. In some medical centers, surgical lasers are shared by several departments and are therefore more cost-effective.
SUMMARY More experience and time are required to determine the advantages of laser surgery in gynecology. For precision surgery through the colposcope, the carbon dioxide laser beam appears to be useful in the control of neoplastic lesions of the vaginal mucosa and possibly of the cervix uter.i. Tumor volume reduction through laser vaporization, especially when a recurrent tumor is attached to the bony pelvis, is an outstanding advantage. Adhesiolysis during myomectomy and reconstructive surgery of the fallopian tubes migh be facilitated by the laser beam. Laser surgery on the vulva, both colposcopically directed and grossly with the CO 2 laser scalpel, might prove to be important for the treatment of various lesions. Detailed technical knowledge, rigid safety precautions, and judicious clinical considerations are essential for competent laser surgery.
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ACKNOWLEDGMENT
The author wishes to acknowledge the support received for laser surgery by the Marx Foundation and the Morgan Pennington Memorial Fund.
REFERENCES 1. Bellina, J. H.: Gynecology and the laser. Contemp. Ob. Gyn., 4:24-34, 1974. 2. Ben-Bassat, M., Ben-Bassat, M., and Kaplan, I.: An ultrastructural study of the cut edges of skin and mucous membrane specimens excised by carbon dioxide laser. In Kaplan, I. (Editor): Laser Surgery. Jerusalem, Jerusalem Academic Press, 1976, 95-100. 3. Fidler, J. P., Law, E., Rockwell, R. J., et al.: Carbon dioxide laser excision of acute burns with immediate autografting. J. Surg. Res., 17:1-11,1974. 4. Goldman, L., Rockwell, R. J., Fidler, J. P., et al.: Investigative laser surgery: safety aspects. Biomed. Eng., 4:415-418, 1969. 5. Kaplan, I., Goldman, J., and Ger, R.: The treatment of erosions of the uterine cervix by means of the CO 2 laser. Obstet. Gynecol., 41 :795-796, 1973. 6. Kiefhaber, P., N ath, G., and Moritz, K: Endoscopical control of massive gastrointestinal hemorrhage by irradiation with a high-power neodymium-yag laser. Prog. Surg., 15:140-155,1977. 7. Krantz, K: (Discussion) Laser treatment of cervical and vaginal neoplasia. Am. J. Obstet. GynecoL, 128:135, 1977. 8. Nath, G., Gorisch, W., and Kiefkaber, P.: First laser endoscopy via a fiberoptic transmission system. Endoscopy, 5:208-213, 1973. 9. Schellhas, H. F., Fidler, J. P., and Rockwell, R. J.: The carbon dioxide laser scalpel in the management of vulvar lesions. In Kaplan, I. (Editor): Laser Surgery Jerusalem, Jerusalem Academic Press, 1976,33-135. 10. Schellhas, H. F., Fidler, J. P., Rockwell, R."J., et al.: Resecting vulvar lesions with the CO 2 laser. Contemp. Ob. Gyn., 6:35-39, 1975. 11. Staehler, V. G., Hofstetter, A., Schiedt, E., et al.: Endoskopische Laser-Bestrahlung von Blasentumoren des Menschen. Fortschr. Med., 95:3-7,1977. 12. Stafl, A., Wilkinson, E. J., and Mattingly, R. F.: Laser treatment of cervical and vaginal neoplasia. Am. J. Obstet. Gynecol., 128:128-136, 1977. 13. Stafl, A., and Mattingly, R. F.: Vaginal adenosis: a precancerous lesion? Am. J. Obstet. GynecoL, 120:666-667, 1974. 14. Stellar, S., Meijer, R., Walia, S., et al.: Carbon dioxide laser debridement of decubitus ulcers. Ann. Surg., 179:230-237,1974. 15. Strong, M. S., and Jako, G.J.: Laser surgery in the larynx. Ann. Otol., 81 :791-798,1972. 16. Toaff, R.: The carbon dioxide laser in gynecological surgery. In Kaplan, I. (Editor): Laser Surgery Jerusalem, Jerusalem Academic Press, 1972, 129-132. 17. Upton, R.: (Discussion) Laser treatment of cervical and vaginal neoplasia. Am. J. Obstet. GynecoL, 128:134, 1977. 18. Verschueren, R.: The CO 2 Laser in Tumor Surgery. AssenlAmsterdam, Van Gorcum, 1976. Department of Obstetrics and Gynecology University of Cincinnati Medical Center 231 Bethesda Avenue Cincinnati, Ohio 45267
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