{"paper_id":"8c1c4448-f390-4015-a712-9cfba4260d31","body_text":"579\nCopyrights © 2019 The Korean Society of Radiology\nComplication Following \nUltrasound-Guided \nHigh-Intensity Focused \nUltrasound for the \nTreatment of Uterine \nAdenomyosis: Case Report \nof CT Imaging Features \n자궁 선근증의 고강도 집속 초음파 치료 이후에 발생된  \n부작용: CT 소견에 대한 증례 보고\nSang Hyup Hong, MD1 , Gil-Sun Hong, MD1* , Choong Wook Lee, MD1,  \nGi Hong Kim, MD2\n1Department of Radiology and Research Institute of Radiology, University of Ulsan College of \nMedicine, Asan Medical Center, Seoul, Korea \n2Department of Radiology, Cheju Halla General Hospital, Jeju, Korea\nHigh intensity focused ultrasound (HIFU) is a non-surgical and non-invasive treatment option \nin patients with uterine myoma and adenomyosis. As the use of HIFU increases in the clinical \npractice, it is important to be aware of imaging findings related to ultrasound (US)-guided HIFU \nablation and its potential complications. However, there are few reports on the imaging find-\nings regarding complications of US-guided HIFU ablation. Here, we report a case of acute com-\nplication after US-guided HIFU ablation, surgically confirmed as thermal injury with necrosis of \nskin, subcutaneous tissue, anterior abdominal wall muscles, peritoneum and uterus.\nIndex terms   HIFU Therapy; Adenomyosis; Abdominal Injuries; Spiral CT\nINTRODUCTION\nHigh-intensity focused ultrasound (HIFU) ablation is performed using ultrasound \n(US) waves to transfer energy through tissue (1). Currently, US-guided HIFU ablation is \nCase Report\nJ Korean Soc Radiol 2019;80(3):579-584\nhttps://doi.org/10.3348/jksr.2019.80.3.579\npISSN 1738-2637 / eISSN 2288-2928\nReceived  June 12, 2018\nRevised  September 3, 2018\nAccepted  September 8, 2018\n*Corresponding author \nGil-Sun Hong, MD\nDepartment of Radiology and \nResearch Institute of Radiology, \nUniversity of Ulsan College of \nMedicine, Asan Medical Center, \n88 Olympic-ro 43-gil, Songpa-gu, \nSeoul 05505, Korea.\nTel  82-2-3010-1548\nFax  82-2-476-0090\nE-mail  gshong@amc.seoul.kr\nThis is an Open Access article \ndistributed under the terms of \nthe Creative Commons Attribu-\ntion Non-Commercial License \n(https://creativecommons.org/\nlicenses/by-nc/4.0) which permits \nunrestricted non-commercial \nuse, distri-bution, and reproduc-\ntion in any medium, provided the \noriginal work is properly cited.\nORCID iDs\nGil-Sun Hong \nhttps:// \norcid.org/0000-0002-0068-9413\nSang Hyup Hong \nhttps:// \norcid.org/0000-0002-8923-9856\n\njksronline.org\n580\nComplication of HIFU Ablation\nregarded as a non-surgical and non-invasive treatment option for fibroids and adenomyosis \nin women who want to preserve fertility (2). Although safe and effective, US-guided HIFU ab-\nlation is known to cause several mild and severe complications (1, 3, 4). Despite this, there \nare few reports on the imaging findings of complications following US-guided HIFU abla-\ntion. We present CT findings of acute complications associated with US-guided HIFU abla-\ntion in a patient who visited the emergency department with abdominal pain.\nCASE REPORT\nA 44-year-old female patient presented to the emergency department with diffuse low ab-\ndominal pain and fever. The patient had undergone ablation of the uterine adenomyosis us-\ning a US-guided HIFU device (YDME FEP-BY02; Yuande Bio-Medical Engineering, Beijing, \nChina) at the outside private hospital three days prior to the presentation. On physical ex-\namination, there were rebound tenderness on palpation and visible skin burn. Speculum \nexamination showed pus-like discharge through the cervix. The patient underwent contrast \nenhanced abdominal CT to find out if there are any US-guided HIFU ablation-related inju-\nries in the abdominal and pelvic organs.\nFig. 1. Complication following ultrasound-guided HIFU ablation for uterine adenomyosis in a 44-year-old \nwoman, presenting with low abdominal pain.\nA, B. Axial CT image shows overlying skin thickening, non-enhancing thickening of the superficial and deep \nfascia at the anterior pelvic wall, peritoneal thickening with fat infiltration in the pelvic cavity, and non-en-\nhancement at bilateral rectus abdominis muscles (A, B; arrowheads). Note the sharply demarcated zone of \nhypodensity with linear lateral margins at the anterior portion of the uterus (B, arrow).\nC, D. Coronal reconstructed CT image shows area of non-enhancement at the bilateral rectus abdominis \nmuscles (C, arrowheads) and zone of hypodensity at the anterior portion of the uterus (D, arrow).\nHIFU = high intensity focused ultrasound\nA\nC\nB\nD\n\nhttps://doi.org/10.3348/jksr.2019.80.3.579\n581\nJ Korean Soc Radiol 2019;80(3):579-584\nThe CT showed the sharply demarcated zone of decreased density with linear lateral mar-\ngins at the anterior portion of the uterus (Fig. 1A–D). In addition, there were hypodense areas \nwith well-demarcated edges, which extend to bilateral rectus abdominal muscles undeniably \nreflecting the characteristic ablation field used in US-guided HIFU ablation. The CT also \nshowed overlying skin thickening, non-enhancing thickening of the superficial and deep fas-\ncia at the anterior pelvic wall, peritoneal thickening with fat infiltration, and small amount \nof extraperitoneal fluid collection in the pelvic cavity. However, the urinary bladder and \nbowel that were considered within the ablation field were not affected. These findings sug-\ngest a thermal injury with necrosis of the skin, subcutaneous tissue, anterior abdominal wall \nmuscles, peritoneum, and uterus.\nThe patient underwent an emergency operation. On inspection, there were skin necrosis \nand dark brownish lesions on the anterior wall of the uterus (8 × 8 cm) presumably due to \nthermal injury (Fig. 1E, F). The rectus muscle and deep fascia were also non-viable. The pa-\ntient underwent total abdominal hysterectomy and debridements of muscle necrosis and \nskin burn, followed by CuraVAC (Daewoong Pharmaceutical, Co., Ltd., Seoul, Korea) applica-\ntion and skin closure. Hemorrhage and necrosis in endometrium and myometrium were \npathologically confirmed. The patient was discharged without postoperative complications. \nSubsequently, the skin burn improved with continuous outpatient clinic visits at the depart-\nment of the plastic surgery.\nDISCUSSION\nThe principle of HIFU therapy is to center the US energy on the target, causing heating, \ncavitation, and direct damage to tumor blood vessels, resulting in tissue ablation. Therefore, \nhigh-energy US waves passing through the focal therapeutic zone can induce damages to in-\nternal organs just anterior or posterior to the focal zone and overlying soft tissue including \nthe skin. However, the majority of complications occurring after US-guided HIFU ablation \nFig. 1. Complication following ultrasound-guided HIFU ablation for uterine adenomyosis in a 44-year-old \nwoman, presenting with low abdominal pain.\nE, F. Photos show (E) skin necrosis in the treated area and (F) thermal injury with necrosis (arrow) on the \nuterine anterior wall in the surgical field.\nHIFU = high intensity focused ultrasound\nE F\n\njksronline.org\n582\nComplication of HIFU Ablation\nare caused by reflections of US waves due to (bowel) gas or bone structures. Skin burns can \nbe caused by poor acoustic windows between the skin and the therapeutic window or by pre-\nvious operation scars. Other possible causes include inaccurate targeting, excessive power \ngeneration, mechanical causes, or unskilled operator. In the monitoring of therapy, unlike \nmagnetic resonance (MR)-guided HIFU ablation which quantifies changes in temperature \nand thermal dose of the treated tissue directly, US-guided HIFU ablation evaluates adequacy \nof ablation based on the changes in grayscale or echogenicity (1, 2). However, changes in so-\nnographic echogenicity are not a direct measure of temperature elevation and merely reflect \nacoustic cavitation or tissue boiling. Thus, there may be a mismatch between the region \nwhere the actual coagulation necrosis occurs and the region where the echogenicity changes \n(1). The sonographic monitoring during ablation has the drawbacks of relatively poor tissue-\ncontrast, limited field of view and progressive deterioration of image quality as the treatment \ncontinues. Therefore, the difficulty in targeting the organs, the drawbacks of therapy moni-\ntoring and poor sonic window by bone or bowel gas can potentially increase the risk of side \neffects of US-guided HIFU ablation. \nPrevious studies classified complications of US-guided HIFU ablation into mild complica-\ntions that can be conservatively managed and severe adverse events that need surgical repair \nwith subsequent sequelae. The incidence and types of side effects of US-guided HIFU-abla-\ntion vary based on previous studies. Five of the 11 studies reported no adverse events or seri-\nous complications (2). Chen et al. (4) reported outcome of the total 9988 patients receiving \nUS-guided HIFU ablation, of which 1273 (12.75%) required no treatment or observation only, \n26 (0.26%) required a minor hospitalization, and only 6 (0.06%) required major therapy. Se-\nvere events requiring major therapy were acute renal failure, intestinal perforation, and her-\nnia in the abdominal wall. Zhang et al. (5) reported other severe adverse events such as skin \nburn requiring surgical repair, bladder injury, and deep vein thrombosis. In addition to the \nacute complication of HIFU ablation, delayed complications may also occur. Kim et al. (6) re-\nported delayed complications such as rapid uterine enlargement and heavy vaginal bleeding \n8 months following HIFU treatment. Quinn et al. (7) reported that 59.3% of patients required \nadditional treatments (hysterectomy, myomectomy, and uterine artery embolization) within \n5 years after HIFU therapy. Ko et al. (8) reported a case of thermal injury to the bowel which \nresulted in perforation after US-guided HIFU ablation for uterine adenomyosis. However, \nthere have been few reports illustrating the image finding of these complications. Most re-\nports of imaging findings relating to US-guided HIFU ablation have focused on the post-pro-\ncedural evaluation of the ablation zone after the procedure using contrast enhanced sonog-\nraphy or contrast-enhanced MR (9, 10). \nOur case demonstrates the CT image findings of acute, severe thermal injury of abdominal \nwall and uterus after US-guided HIFU ablation for uterine adenomyosis. Hwang et al. (3) re-\nported imaging findings of delayed intestinal perforation and necrosis of the rectus muscle \n29 days after HIFU treatment for uterine leiomyoma. The CT image findings of our case were \nsimilar to Hwang’s report except bowel perforation in that there were hypodense areas with \nlinear well-demarcated edges which are thought to correspond to the margin of the charac-\nteristic ablation field used in US-guided HIFU ablation. However, unlike Hwang’s report, our \nreport presents a rare case of severe thermal injury in its acute phase after US-guided HIFU \n\nhttps://doi.org/10.3348/jksr.2019.80.3.579\n583\nJ Korean Soc Radiol 2019;80(3):579-584\nablation. The complications of HIFU ablation are very rare and most cases are with minor \ngynecologic symptoms. However, regardless of when the procedure was performed, clini-\ncians should consider the possibility of serious complication related to US-guided HIFU abla-\ntion in patients who complain of gynecologic symptom and abdominal pain with previous \nhistory of US-guided HIFU ablation. Radiologists should understand the mechanism of com-\nplications of US-guided HIFU therapy (i.e., the organs injury within ablation field due to ex-\ncessive power generation or inaccurate targeting and complications by the reflection of US \nwaves due to bowel gas or bone structures within the narrow pelvic cavity) and carefully re-\nview images of organs such as skin, small bowel, uterus, vascular structure, and urinary \nbladder that can be potentially damaged. \nMost of the previous reports have focused on the types and incidence of complications of \nUS-guided HIFU ablation without CT findings or treatment monitoring. In this case, we pres-\nent CT findings of acute complications associated with US-guided HIFU ablation in a patient \nwho presented to the emergency department with abdominal pain. We review the mecha-\nnism of complications of US-guided HIFU therapy in order to alert the radiologists to pay \nclose attention to the possible serious complications of US-guided HIFU ablation. The radiol-\nogists should carefully evaluate structures within focal zone of US-guided HIFU ablation and \nalso consider the injuries to adjacent organs by the reflection of US waves.\nConflicts of Interest\nThe authors have no potential conflicts of interest to disclose.\nREFERENCES\n1. Kim YS, Rhim H, Choi MJ, Lim HK, Choi D. High-intensity focused ultrasound therapy: an overview for radi-\nologists. Korean J Radiol 2008;9:291-302\n2. Cheung VY. Current status of high-intensity focused ultrasound for the management of uterine adenomyo-\nsis. Ultrasonography 2017;36:95-102\n3. Hwang DW, Song HS, Kim HS, Chun KC, Koh JW, Kim YA. Delayed intestinal perforation and vertebral os-\nteomyelitis after high-intensity focused ultrasound treatment for uterine leiomyoma. Obstet Gynecol Sci \n2017;60:490-493\n4. Chen J, Chen W, Zhang L, Li K, Peng S, He M, et al. Safety of ultrasound-guided ultrasound ablation for \nuterine fibroids and adenomyosis: a review of 9988 cases. Ultrason Sonochem 2015;27:671-676\n5. Zhang L, Zhang W, Orsi F, Chen W, Wang Z. Ultrasound-guided high intensity focused ultrasound for the \ntreatment of gynaecological diseases: a review of safety and efficacy. Int J Hyperthermia 2015;31:280-284\n6. Kim HK, Kim D, Lee MK, Lee CR, Kang SY, Chung Y J, et al. Three cases of complications after high-intensity \nfocused ultrasound treatment in unmarried women. Obstet Gynecol Sci 2015;58:542-546\n7. Quinn SD, Vedelago J, Gedroyc W, Regan L. Safety and five-year re-intervention following magnetic reso-\nnance-guided focused ultrasound (MRgFUS) for uterine fibroids. Eur J Obstet Gynecol Reprod Biol \n2014;182:247-251\n8. Ko JK, Seto MT , Cheung VY. Thermal bowel injury after ultrasound-guided high-intensity focused ultra-\nsound for uterine adenomyosis. Ultrasound Obstet Gynecol 2018;52:282-283\n9. Cheng CQ, Zhang, RT , Xiong Y, Chen L, Wang J, Huang GH, et al. Contrast-enhanced ultrasound for evalua-\ntion of high-intensity focused ultrasound treatment of benign uterine diseases: retrospective analysis of \ncontrast safety. Medicine (Baltimore) 2015;94:e729 \n10. Zhao WP , Chen JY, Chen WZ. Dynamic contrast-enhanced MRI serves as a predictor of HIFU treatment out-\ncome for uterine fibroids with hyperintensity in T2-weighted images. Exp Ther Med 2016;11:328-334\n\njksronline.org\n584\nComplication of HIFU Ablation\n자궁 선근증의 고강도 집속 초음파 치료 이후에 발생된  \n부작용: CT 소견에 대한 증례 보고\n홍상협1 · 홍길선1* · 이충욱1 · 김기홍2\n초음파 유도 고강도 집속 초음파는 자궁 근종과 선근증의 비수술적, 비침습적 치료 방법이\n다. 의료분야에서 초음파 유도 고강도 집속 초음파를 이용한 치료가 증가함에 따라 영상의학\n과 의사들은 이와 관련된 합병증의 영상 소견을 아는 것이 중요하다. 우리는 최근에 초음파 \n유도 고강도 집속 초음파 치료를 받은 후 발생한 복부 통증으로 응급실에 내원한 44세 여자 \n환자의 증례를 보고하자고 한다. 본 증례는 초음파 유도 고강도 집속 초음파의 급성 합병증으\n로 복벽에서 자궁에 이르는 부위에 괴사를 동반한 열손상의 영상 소견을 잘 보여주고 있다.\n1울산대학교 의과대학 서울아산병원 영상의학과, 영상의학연구소, 2제주한라병원 영상의학과","source_license":"CC0","license_restricted":false}