{"paper_id":"aae8dc42-8755-49ae-a67c-a091204280ae","body_text":"Successful Microwave Endometrial Ablation in a\nUterus Enlarged by Adenomyosis\n言語: English\n出版者: OSAKA CITY MEDICAL CENTER\n公開日: 2018-07-17\nキーワード: Microwave endometrial ablation,\nAdenomyosis, Menorrhagia\n作成者: 金岡, 靖, 平井, 光三, 石河, 修\nメールアドレス: \n所属: Osaka City University, Osaka City University,\nOsaka City University\nメタデータ\nhttps://ocu-omu.repo.nii.ac.jp/records/2020157URL\n\nKanaoka Yasushi, Hirai Kouzo, Ishiko Osamu . Successful Microwave Endometrial Ablation in a \nUterus Enlarged by Adenomyosis. Osaka City Medical Journal. 2004, 50, 1, 47-51. \nSuccessful Microwave Endometrial Ablation in \na Uterus Enlarged by Adenomyosis \n  \n \nKanaoka Yasushi, Hirai Kouzo, Ishiko Osamu \n \nCitation Osaka City Medical Journal. 50(1); 47-51 \nIssue Date 2004-06 \nType Journal Article \nTextversion Publisher \nRight \n© Osaka City Medical Association.  \nhttps://osakashi-igakukai.com/.  \n \n \nPlaced on: Osaka City University Repository \n\nOsaka City Med.  J. Vol. 50, 47-51, 2004\nReceived  October  31,  2003;  accepted  April  13,  2004\nCorrespondence to: Yasushi Kanaoka, MD.\nDepartment of Obstetrics and Gynecology, Osaka City University, Graduate School of Medicine,\n1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan\nTel: +81-6-6645-3861;   Fax: 81-6-6646-5800\nE-mail: kanaokamd@med.osaka-cu.ac.jp\nSuccessful Microwave Endometrial Ablation in a Uterus Enlarged\nby Adenomyosis\nYASUSHI KANAOKA, KOUZO HIRAI, and OSAMU ISHIKO\nDepartment of Obstetrics and Gynecology, \nOsaka City University, Graduate School of Medicine \nAbstract\nAdenomyosis can cause severe menorrhagia, which is a common indicator of the need for\nhysterectomy.  None of the ablative techniques developed over the last two decades are of use in\ntreating menorrhagia in a uterus enlarged by deep adenomyosis.  Using a curved microwave\napplicator specifically developed for enlarged uterine cavities, microwave endometrial ablation at\na frequency of 2.45 GHz was successfully applied in the treatment of menorrhagia in a patient\nwith adenomyosis and an enlarged uterine cavity 12 cm in length.  Two weeks after the operation, the\npatient experienced a menstrual period of ten days with no flooding.  Menstrual duration\ngradually decreased to six days over the following six months.  The quality of life score recovered\nto within the normal range six months after the operation.  The post-operative sub-endometrial\nlow signal intensity zone on the T2-weighted magnetic resonance images, which corresponds to\nthe region of necrotic tissue, vanished 12 months after the operation.  Although microwave\nendometrial ablation using the curved applicator could not treat bleeding from deep adenomyosis\nlesions, it improved menorrhagia in the uterus, which would conventionally require a hysterectomy.\n,FZ\u0001XPSET\u001bMicrowave endometrial ablation; Adenomyosis; Menorrhagia\nIntroduction\nAdenomyosis is a tumor-like lesion that causes a disabling condition associated with\nmenorrhalgia and menorrhagia.  Since no effective hormone therapy is known, hysterectomy is\nindicated in many cases to relieve the refractory symptoms.  For menorrhagia, endometrial\nablation is an alternative to hysterectomy, however none of the ablative techniques developed\nover the last two decades have been of use in treating menorrhagia in a uterus enlarged by\nadenomyosis, because they cannot treat adenomyosis lesions located deep in the myometrium\n1).\nIn addition, an enlarged uterus is one of the contraindications for conventional endometrial\nablation\n2).  \nRecently, the applicability of microwave endometrial ablation (MEA) at a frequency of 2.45 GHz\n-47 -\n\nusing a curved microwave applicator was reported for patients with an enlarged uterus and\ndistorted uterine cavity more than 12 cm in length 3).  In addition, by selecting the microwave\npower and irradiation time the depth of microwave thermal necrosis is adjustable.  Therefore,\nMEA at 2.45 GHz is a candidate for the treatment of menorrhagia in an enlarged uterus as a\nresult of adenomyosis.  Because necrotic tissue often maintains its microscopic structure for more\nthan three months without signs of necrosis, microwave thermal necrosis is often referred to as\ncoagulation\n4).\nWith the use of magnetic resonance imaging (MRI), this study reports a case of adenomyosis\nwith an enlarged uterine cavity that was successfully treated by MEA.\nCase Report\nThe patient, who was a 46-year-old bipara and head of a company, had been suffering from\nmenorrhagia due to adenomyosis since the age of 35.  Menorrhalgia was not severe.  As her\nKanaoka et al\n-48 -\nFigure 1. (a), T2-weighted MR image before the MEA (sagittal section).  The endometrium is\nshown as the high intensity area (arrow).  (b), T2-weighted MR image one month after the MEA\n(sagittal section).  The uterine cavity is shown as a thin line (thin arrow) with high intensity,\nwhich is surrounded by a low intensity area (thick arrow).  (c), T2-weighted MR image three\nmonths after the MEA (sagittal section).  The uterine cavity is unclear and the low intensity area\n(arrow) is smaller than in Figure 1b.  (d), Gd-enhanced T1-weighted MR image three months after the\nMEA (sagittal section).  The contrast medium shows that the uterine cavity is surrounded by\navascular tissue, which is enclosed by a thin high intensity line (arrow).  (e), T2-weighted MR\nimage 12 months after the MEA (sagittal section).  The uterine cavity was depicted as a high\nintensity area (long arrow), which suggests that the endometrial tissue is regrowing.  The short\narrow shows a new myoma node at the anterior wall of the cervix.  (f), Gd-enhanced T1-weighted\nMR image 12 months after the MEA (sagittal section).  The avascular area three months after the\nMEA is not depicted.\n\nhemoglobin level was found to be 5.8 g/dL, her attendant doctor administered iron supplements\nfor two years, however, the menorrhagia continued to worsen over this period as her uterus\ngradually grew.  Due to flooding, the patient was unable to work or go out for the first 3 days of\nmenstrual bleeding, which brought about palpitations and general fatigue due to severe anemia.\nThe duration of bleeding was 12 days.  The patient was therefore referred to our hospital.\nOn admission, the patient’s hemoglobin level was 8.3 g/dL just before her next menstruation\nperiod.  Bimanual examination revealed that her uterus was larger than a newborn’s head in\nsize.  MRI analysis revealed thickened uterine walls due to adenomyosis and the uterine cavity\nwas 12 cm in length (Fig. 1a).  Endometrial malignant diseases were ruled out by an endometrial\nbiopsy.  The patient’s status was evaluated by completion of a questionnaire for menorrhagia\n(Table 1)\n5).  She scored 13 points, which showed a deteriorated quality of life (QOL).  Since the\npatient did not want to interrupt her work schedule with a long hospital admission, she selected\nMEA as an alternative to hysterectomy after informed consent.  \nA microwave tissue coagulator (Microtaze OT 110M, Azwell Inc. Osaka, Japan) and curved\nmicrowave applicator, which was developed by the authors specifically for MEA in an enlarged\nuterus with a distorted uterine cavity, were employed (Fig. 2).  Using transabdominal\nultrasound, the applicator can reach the uterotubal area and fundus, which tend to remain\nuntreated when using the straight intra-uterine instruments available for conventional\nendometrial ablation when the uterine cavity is enlarged and distorted.  The patient did not\nundergo any endometrial thinning by administration of a gonadotropin releasing hormone\nagonist or danazol.  Microwave coagulation was performed by pressing the tip of the applicator to\nthe uterine wall to coagulate the basal layer of the endometrium and adjacent myometrium as\ndeeply as possible.  Nine coagulation sites including both uterotubal areas and the fundus were\nselected under ultrasonography so that no untreated endometrium remained.  The microwave\noutput at the applicator tip and the duration were 40 W and 50 seconds, respectively, for each\nMEA for Adenomyosis\n-49 -\nFigure 2. The curved microwave applicator, which is 4 mm in diameter.\n\ncoagulation site, except for two sites on the midline of the uterine cavity where the duration\nincreased two-fold.  It took 11 minutes to perform the MEA uneventfully under general\nanesthesia using a laryngeal tube.  \nA hysteroscopic examination performed following completion of the MEA revealed that the\nuterine cavity was covered with thin yellowish tissue and no intact endometrium was observed.\nTwo weeks after the MEA, the patient experienced menstrual bleeding lasting for ten days\nwithout flooding.  Menstruation duration gradually decreased to six days over the following six\nmonths.  Six months after the MEA, the patient’s QOL score decreased to 3 points (Table 1) and\nshe was categorized into the group of healthy women.  The patient was satisfied with the results.\nMagnetic resonance imaging was performed before, one month, three months and twelve months\nafter the MEA.  The endometrial lining of the uterine cavity and the junctional zone in the\nmyometrium were not depicted by the T2-weighted MRI taken one month after the MEA \n(Fig. 1b), although the uterine cavity was conserved and sounding was possible.  Three months\nafter the MEA, the low intensity area became smaller than it was one month after the operation\n(Fig. 1c).  A Gd-enhanced T1-weighted MRI revealed that an avascular area 7-9 mm in depth\nentirely surrounded the uterine cavity (Fig. 1d).  Twelve months after the MEA, the endometrial\nlining was depicted on a T2-weighted image (Fig. 1e).  The avascular area was not identified by\nan enhanced MRI study (Fig. 1f).\nDiscussion\nIn general, the MEA induces thermal necrosis in the endometrium and myometrium within \n7 mm of the surface of the uterine cavity.  This necrotic tissue is replaced by granulation tissue\nafter several months and finally the uterine cavity is obliterated with fibrous tissue\n5).  At the\nstandard microwave setting MEAs cannot fully treat adenomyosis that are thicker than 7 mm\nfor dysfunctional uterine bleeding.  Therefore, in this study the applicator was held to the\nuterine wall with pressure so its tip was as close as possible to the myometrium ensuring that\nKanaoka et al\n-50 -\nMenorrhagia Yes/No Score Before Six months \nDysmenorrhea If  yes    2 0 0\nCycle length  If  ʼ 28   0 0 0\nIf  24-27 1\n If  ʻ 24  2\nHeavy days Score 1 each day 5 0\nSanitary wear If double 2 2 0\nFrequency of changing  \nʻ 2 h      1 1 1\n ʻ 1 h      2\nClots If  yes    1 1 1\nFlooding If  yes    1 1 0\nHousebound/ If  yes    2 2 0\ntime off work\nDuration of problem       If \nʼ 5 years 1 1\n(pre-op)\nIf any bleeding If  yes    1 1\n(post-op) 2\nTotal 13 3\nTable 1. Menstrual score before and six months after the MEA\n\neach coagulation site included as many adenomyosis lesions as possible.  One month later, MRI\nanalysis revealed that the eutopic endometrium was completely coagulated.  Hysteroscopy just\nafter the MEA is convenient for detecting untreated myometrium, although it can only offer\ninformation about the surface of the endometrium.  On the other hand, T2-weighted MRIs can\ndepict the endometrium and junctional zone, but enhanced MRIs are needed to assess the\ncoagulated area more clearly\n6).  In this case, the coagulated area was recognized on Gd-enhanced\nT1-weighted images.  The coagulated area surrounding the uterine cavity was enclosed by a thin\nline of which the signal intensity was enhanced by the contrast medium one month and three\nmonths later.  This line seems to correspond to the granulation tissue growing between the living\ntissue and coagulated tissue.  \nOne month after MEA, the eutopic endometrium was not depictable, although menstruation\ndid occur.  The persisting menstruation seems therefore to come from an adenomyosis lesion.\nBleeding from a deep adenomyosis lesion through long thin canals might cause a prolonged\nperiod following an MEA.  Flooding on days 1 to 3, which was relieved after the MEA, seemed to\nbe mainly caused by the eutopic endometrium.  As previously reported, menorrhagia tends to\npersist after endometrial ablation in deep adenomyosis cases.  The present case demonstrates\nthat the glands of adenomyosis lesions maintain their connection with the uterine cavity.  \nMicrowaves at 2.45 GHz supplied by the curved applicator could improve menorrhagia in a\nuterus enlarged by adenomyosis, but it is difficult to coagulate all the adenomyosis lesions at the\nstandard setting of microwaves for MEA.  Based on the results of an analysis using the finite\nelement method of the electric field and temperature distribution in the myometrium around the\napplicator tip (unpublished data), the microwave duration was doubled for two coagulation sites,\nwhich induced a 30% increase in the depth of the coagulation area.  To treat adenomyosis tissues\ndeep in the myometrium, it is conceivable to coagulate the adenomyosis lesions using a thin\nneedle type microwave electrode\n7) introduced though a transcervical puncture.  Addition of in situ\ncoagulation within an adenomyosis lesion might be effective, as well as coagulation from the\ninner surface with an increased output and longer duration of the microwaves.\nReferences\n1. McCausland V, McCausland A. The response of adenomyosis to endometrial ablation/resection. Hum\nReprod Update 1998;4:350-359.\n2. Downes E, O’Donovan P. Microwave endometrial ablation in the management of menorrhagia: current\nstatus. Curr Opin Obstet Gyn 2000;12:293-296.\n3. Kanaoka Y, Hirai K, Ishiko O. Microwave endometrial ablation for an enlarged uterus. Arch Gynecol\nObstet 2003;269:30-32.\n4. Mori I, Ozaki T, Tabuse K, Kakudo K. Microwave and cell death, a novel cell death different from necrosis\nand apoptosis. J Microwave Surgery 2003;21:17-23.\n5. Hodgson DA, Feldberg IB, Sharp N, Cronin N, Evans M, Hirschowitz L. Microwave endometrial ablation:\ndevelopment, clinical trials and outcomes at three years. Brit J Obstet Gynaec 1999;106:684-694.\n6. Olson S, Wallage S, Deans HE, Wallis F, Parkin DE. Magnetic resonance imaging appearances of the\nuterus following microwave endometrial ablation. Clin Radiol 2002;57:926-929.\n7. Kanaoka Y, Mine M, Ogita S. Microwave tissue coagulation: a possible alternative to myomectomy. J\nGynecol Tech 1998;4:29-33.\nMEA for Adenomyosis\n-51 -","source_license":"CC0","license_restricted":false}