International Journal of Urology (2015) 22, 710--712
doi: 10.1111/iju.12775
Case Report
Spontaneous rupture of a renal angiomyolipoma at 25 weeks of pregnancy treated with transarterial embolization: A case report and review of the literature Shingo Myoen,1 Koji Mitsuzuka,1 Hideo Saito,1 Hideki Ota,2 Kei Takase2 and Yoichi Arai1 Departments of 1Urology and 2Diagnostic Radiology, Tohoku University School of Medicine, Sendai, Japan Abbreviations & Acronyms AML = angiomyolipoma CT = computed tomography TAE = transcatheter arterial embolization TS = tuberous sclerosis Correspondence: Koji Mitsuzuka M.D., Ph.D., Department of Urology, Tohoku University School of Medicine, Seiryo-machi, Aoba-ku, Sendai, Miyagi 9808574, Japan. Email: [email protected] Received 22 October 2014; accepted 26 February 2015. Online publication 16 April 2015
Abstract: Treatment for ruptured renal angiomyolipoma in pregnancy requires immediate and appropriate decision-making based on the condition of the mother and fetus, and gestational age. A 37-year-old woman at 25 weeks of pregnancy presented with severe right flank pain. Computed tomography showed a ruptured right renal angiomyolipoma (8 cm in diameter). The maternal and fetal conditions were stable. Transcatheter arterial embolization was carried out electively 4 days after the rupture. Minimization of radiation exposure to the fetus was achieved by X-ray shielding for the fetus, low-dose-rate fluoroscopy, minimal angiography imaging and a color Doppler ultrasonography-guided procedure. Although threatened premature labor occurred because of post-embolization syndrome, the pregnancy was continued until cesarean section at 37 weeks of pregnancy.
Key words: angiomyolipoma, indication, pregnancy, radiation exposure, transcatheter arterial embolization.
Introduction Rupture of renal AML in pregnancy is relatively rare, and no standard treatment strategy exists. TAE is usually the first choice of treatment for ruptured AML, whereas the timing of TAE depends on maternal and fetal conditions, and gestational age. We report a case of ruptured AML in a pregnant woman successfully treated by elective TAE with minimal radiation exposure.
Case report A 37-year-old woman, 25 weeks pregnant, presented with sudden severe right flank pain and visited a neighborhood hospital. Obstetric or gynecological disease was ruled out, and CT showed a right renal tumor (8 cm in diameter) containing a fat component with retroperitoneal hematoma (Fig. 1). Although a single blood transfusion was required, her general condition was stable. She was transferred to Tohoku University Hospital, Sendai, Japan, for management of the renal tumor and her fetus. The patient had no past medical or genetic disorders except a previous cesarean section as a result of cephalo-pelvic disproportion. Laboratory data were: white blood cells 9600/μL, lactase dehydrogenase 242I U/L, C-reactive protein 7.0 mg/dL, creatinine 0.31 mg/dL and hemoglobin 9.3 g/dL after a four-unit red blood cell transfusion. Under epidural anesthesia, TAE was carried out 4 days after the rupture. To reduce radiation exposure to the fetus, the procedure was carried out under low-dose-rate radiation, with no direct radiation to the fetus and use of color Doppler ultrasonography. Angiography showed the feeding artery to the tumor with micro-aneurysms (Fig. 2, arrows), which were embolized with gelatin sponge and coils. An aneurysmal stain caudal from the tumor (Fig. 2, arrow heads) was not considered as the responsible lesion, because the stain appeared in the later phase than the micro-aneurysms on angiogram, there was no evidence of active bleeding at the time, and the procedure time needed to be minimal to reduce radiation exposure. Color Doppler ultrasonography showed no blood flow in the tumor after embolization (Fig. 3). Threatened premature labor occurred because of post-embolization syndrome, but it was managed by conservative therapy. She was discharged 2 weeks later. The pregnancy was completed uneventfully, and a normal baby was delivered by cesarean section at 37 weeks of pregnancy. Contrastenhanced CT after the delivery showed a 10-mm aneurysm in the AML, which corresponded to the aneurysmal stain at the previous TAE. A total of 5 months after the delivery, additional TAE was carried out for the aneurysmal stain and recurrent micro-aneurysms. 710
© 2015 The Japanese Urological Association
Rupture of renal AML during pregnancy
Fig. 1 CT shows a right renal tumor (arrows) with a diameter of 8 cm containing a fat component with retroperitoneal hematoma (arrow heads).
Fig. 2 Angiography shows tumor stain with a micro-aneurysm (arrows). An aneurysmal stain (arrow heads) caudal from the tumor was not considered the origin of the rupture.
Discussion AML rupture during pregnancy is relatively rare, but AML during pregnancy tends to grow rapidly and rupture as a result of the hormonal environment, and increasing abdominal pressure and blood volume.1–3 In the 45 cases with ruptured AML during pregnancy that were reviewed, the average tumor size was 9.6 cm, occurring around the 26th week of gestation. Six © 2015 The Japanese Urological Association
cases (13%) had TS. Currently, TAE is the standard treatment procedure for ruptured AML, as TAE is less invasive, causes minimal loss of renal function and prevents re-rupture in the long term.4,5 However, there are no reports about the indications of TAE or radiation exposure during pregnancy. Thus, several important issues when considering TAE for ruptured AML during pregnancy are discussed. First, the general maternal and fetal conditions must be evaluated immediately. We reviewed the 45 cases to compare relationships between fetal prognosis and maternal and fetal conditions (Table 1), classified as stable or unstable. Unstable (n = 20) was defined as being hemodynamically unstable with shock or requiring continuous blood transfusions and/or presence of signs of fetal distress. Stable (n = 22) was defined as other than unstable. In three cases, the condition was unclear. In the stable group, 20 cases (91%) completed pregnancy and term delivery. In contrast, in nine unstable group cases (45%), urgent cesarean section was required, and six cases (30%) resulted in fetal death. Thus, when hemodynamic instability is present, urgent intervention is required. Second, it is important to consider the potential effect of fetal radiation exposure. According to guidelines for obstetrical practice in Japan,6 an embryo until 10 weeks has an increased risk of malformation at dose of ≥50 mGy. The central nervous system of a fetus at 10–27 weeks might be affected unfavorably at a dose of ≥100 mGy. Indeed, the risk of childhood cancer is increased in a dose-related manner. When considering these risks, fetal exposure must be minimized. Although magnetic resonance imaging should usually be recommended instead of CT for imaging of AML during pregnancy in terms of radiation exposure, magnetic resonance imaging was not carried out in the present case, because CT that had already been carried out at the previous hospital gave us sufficient information. Third, the risk of re-rupture during pregnancy should be considered if observation is chosen. Some reports noted that conservative therapy could be managed if maternal and fetal conditions were stable, whereas close follow up and emergency response for re-rupture are required.7 In our review, 14 of 45 cases were treated conservatively. Re-rupture occurred in two cases (14%) during pregnancy. One case had TS. Steiner et al. showed that AML in patients with TS was likely to grow rapidly,8 and might be better treated with TAE than with observation. In the present case, urgent treatment was not required because maternal and fetal conditions were stable. The patient did not have TS, and observation could have been an alternative treatment option when considering fetal radiation exposure. However, there was a risk of re-rupture during pregnancy because of the large size (8 cm) of the AML.9 Yanai et al. suggested the necessity of intervention to prevent AML rupture during pregnancy for patients with AML >4 cm.10 In order to reduce the radiation dose as much as possible, we used low-pulse-rate (7.5 pulses/s) for fluoroscopy and minimal angiography. As their image quality was compromised, color Doppler ultrasonography was used for evaluation of blood flow in the tumor. The fetus was always kept outside of direct radiation. As a result, the radiation dose at the mother’s skin was 13.37 mGy, which was lower than the threshold dose for fetal malformation. The fetal radiation dose was presumed to be much lower than the mother’s. 711
S. MYOEN ET AL.
Fig. 3 Color Doppler ultrasonography before and after the transarterial embolization showing no blood flow in the tumor (arrows).
before
Table 1 Fetal prognosis according to conditions of the mother and fetus at the time of renal AML rupture based on the literature review of 45 cases
after
Conflict of interest None declared.
Conditions of mother and fetus Stable Unstable Unclear
n
Term delivery
Urgent cesarean section
Fetal death
Unclear
22 20 3
20 (91%) 2 (10%) –
0 (0%) 9 (45%) –
0 (0%) 6 (30%) –
2 (9%) 3 (15%) –
When considering the strategy of treatment for ruptured AML during pregnancy, hemodynamic stability of the mother and fetus must be evaluated first. If unstable, active treatment including cesarean section should be carried out immediately to avoid fetal death. If stable, conservative treatment or elective TAE could be selected, depending on the risk of re-rupture, gestational age and estimated exposure dose. When TAE is planned, efforts to minimize fetal exposure should be made. However, TAE cannot always be carried out with negligible dosage, as in the present case. Limitations of procedure time, complexity of the blood stream, low-quality imaging because of low-dose exposure or shielding of the fetus, the positional relationship between the AML and the fetus, and postembolization syndrome could also be associated with success of TAE. It is essential to inform patients of the benefits and risks of each treatment.
712
References 1. Eble JN. Angiomyolipoma of kidney. Semin. Diagn. Pathol. 1998; 15: 21–40. 2. Zapardiel I, Delafuente-Valero J, Bajo-Arenas JM. Renal angiomyolipoma during pregnancy: review of the literature. Gynecol. Obstet. Invest. 2011; 72: 217–9. 3. Komeya M, Matsumoto T, Fujinami K, Senga Y, Asakura T, Goto A. Rupture of renal angiomyolipoma during pregnancy: a case report. Hinyokika Kiyo 2010; 56: 261–4. 4. Ramon J, Rimon U, Garniek A et al. Renal angiomyolipoma: long-term results following selective arterial embolization. Eur. Urol. 2009; 55: 1155–61. 5. Ewalt DH, Diamond N, Rees C et al. Long-term outcome of transcatheter embolization of renal angiomyolipomas due to tuberous sclerosis complex. J. Urol. 2005; 174: 1764–6. 6. Japan Society of Obstetrics and Gynecology, Japan Association of Obstetricians and Gynecologists. Guidelines for obstetrical practice in Japan: Japan Society of Obstetrics and Gynecology (JSOG) and Japan Association of Obstetricians and Gynecologists (JAOG) 2011 edition. J. Obstet. Gynaecol. Res. 2011; 37: 1174–97. 7. Storm DW, Mowad JJ. Conservative management of a bleeding renalangiomyolipoma in pregnancy. Obset. Gynecol. 2006; 107: 490–2. 8. Steiner MS, Goldman SM, Fishman EK, Marshall FF. The natural history of renal angiomyolipoma. J. Urol. 1993; 150: 1782–6. 9. Oesterling JE, Fishman EK, Goldman SM, Marshall FF. The management of renal angiomyolipoma. J. Urol. 1986; 135: 1121–4. 10. Yanai H, Sasagawa I, Kubota Y et al. Spontaneous hemorrhage during pregnancy secondary to renal angiomyolipoma. Urol. Int. 1996; 56: 188–91.
© 2015 The Japanese Urological Association
doi: 10.1111/iju.12775
Case Report
Spontaneous rupture of a renal angiomyolipoma at 25 weeks of pregnancy treated with transarterial embolization: A case report and review of the literature Shingo Myoen,1 Koji Mitsuzuka,1 Hideo Saito,1 Hideki Ota,2 Kei Takase2 and Yoichi Arai1 Departments of 1Urology and 2Diagnostic Radiology, Tohoku University School of Medicine, Sendai, Japan Abbreviations & Acronyms AML = angiomyolipoma CT = computed tomography TAE = transcatheter arterial embolization TS = tuberous sclerosis Correspondence: Koji Mitsuzuka M.D., Ph.D., Department of Urology, Tohoku University School of Medicine, Seiryo-machi, Aoba-ku, Sendai, Miyagi 9808574, Japan. Email: [email protected] Received 22 October 2014; accepted 26 February 2015. Online publication 16 April 2015
Abstract: Treatment for ruptured renal angiomyolipoma in pregnancy requires immediate and appropriate decision-making based on the condition of the mother and fetus, and gestational age. A 37-year-old woman at 25 weeks of pregnancy presented with severe right flank pain. Computed tomography showed a ruptured right renal angiomyolipoma (8 cm in diameter). The maternal and fetal conditions were stable. Transcatheter arterial embolization was carried out electively 4 days after the rupture. Minimization of radiation exposure to the fetus was achieved by X-ray shielding for the fetus, low-dose-rate fluoroscopy, minimal angiography imaging and a color Doppler ultrasonography-guided procedure. Although threatened premature labor occurred because of post-embolization syndrome, the pregnancy was continued until cesarean section at 37 weeks of pregnancy.
Key words: angiomyolipoma, indication, pregnancy, radiation exposure, transcatheter arterial embolization.
Introduction Rupture of renal AML in pregnancy is relatively rare, and no standard treatment strategy exists. TAE is usually the first choice of treatment for ruptured AML, whereas the timing of TAE depends on maternal and fetal conditions, and gestational age. We report a case of ruptured AML in a pregnant woman successfully treated by elective TAE with minimal radiation exposure.
Case report A 37-year-old woman, 25 weeks pregnant, presented with sudden severe right flank pain and visited a neighborhood hospital. Obstetric or gynecological disease was ruled out, and CT showed a right renal tumor (8 cm in diameter) containing a fat component with retroperitoneal hematoma (Fig. 1). Although a single blood transfusion was required, her general condition was stable. She was transferred to Tohoku University Hospital, Sendai, Japan, for management of the renal tumor and her fetus. The patient had no past medical or genetic disorders except a previous cesarean section as a result of cephalo-pelvic disproportion. Laboratory data were: white blood cells 9600/μL, lactase dehydrogenase 242I U/L, C-reactive protein 7.0 mg/dL, creatinine 0.31 mg/dL and hemoglobin 9.3 g/dL after a four-unit red blood cell transfusion. Under epidural anesthesia, TAE was carried out 4 days after the rupture. To reduce radiation exposure to the fetus, the procedure was carried out under low-dose-rate radiation, with no direct radiation to the fetus and use of color Doppler ultrasonography. Angiography showed the feeding artery to the tumor with micro-aneurysms (Fig. 2, arrows), which were embolized with gelatin sponge and coils. An aneurysmal stain caudal from the tumor (Fig. 2, arrow heads) was not considered as the responsible lesion, because the stain appeared in the later phase than the micro-aneurysms on angiogram, there was no evidence of active bleeding at the time, and the procedure time needed to be minimal to reduce radiation exposure. Color Doppler ultrasonography showed no blood flow in the tumor after embolization (Fig. 3). Threatened premature labor occurred because of post-embolization syndrome, but it was managed by conservative therapy. She was discharged 2 weeks later. The pregnancy was completed uneventfully, and a normal baby was delivered by cesarean section at 37 weeks of pregnancy. Contrastenhanced CT after the delivery showed a 10-mm aneurysm in the AML, which corresponded to the aneurysmal stain at the previous TAE. A total of 5 months after the delivery, additional TAE was carried out for the aneurysmal stain and recurrent micro-aneurysms. 710
© 2015 The Japanese Urological Association
Rupture of renal AML during pregnancy
Fig. 1 CT shows a right renal tumor (arrows) with a diameter of 8 cm containing a fat component with retroperitoneal hematoma (arrow heads).
Fig. 2 Angiography shows tumor stain with a micro-aneurysm (arrows). An aneurysmal stain (arrow heads) caudal from the tumor was not considered the origin of the rupture.
Discussion AML rupture during pregnancy is relatively rare, but AML during pregnancy tends to grow rapidly and rupture as a result of the hormonal environment, and increasing abdominal pressure and blood volume.1–3 In the 45 cases with ruptured AML during pregnancy that were reviewed, the average tumor size was 9.6 cm, occurring around the 26th week of gestation. Six © 2015 The Japanese Urological Association
cases (13%) had TS. Currently, TAE is the standard treatment procedure for ruptured AML, as TAE is less invasive, causes minimal loss of renal function and prevents re-rupture in the long term.4,5 However, there are no reports about the indications of TAE or radiation exposure during pregnancy. Thus, several important issues when considering TAE for ruptured AML during pregnancy are discussed. First, the general maternal and fetal conditions must be evaluated immediately. We reviewed the 45 cases to compare relationships between fetal prognosis and maternal and fetal conditions (Table 1), classified as stable or unstable. Unstable (n = 20) was defined as being hemodynamically unstable with shock or requiring continuous blood transfusions and/or presence of signs of fetal distress. Stable (n = 22) was defined as other than unstable. In three cases, the condition was unclear. In the stable group, 20 cases (91%) completed pregnancy and term delivery. In contrast, in nine unstable group cases (45%), urgent cesarean section was required, and six cases (30%) resulted in fetal death. Thus, when hemodynamic instability is present, urgent intervention is required. Second, it is important to consider the potential effect of fetal radiation exposure. According to guidelines for obstetrical practice in Japan,6 an embryo until 10 weeks has an increased risk of malformation at dose of ≥50 mGy. The central nervous system of a fetus at 10–27 weeks might be affected unfavorably at a dose of ≥100 mGy. Indeed, the risk of childhood cancer is increased in a dose-related manner. When considering these risks, fetal exposure must be minimized. Although magnetic resonance imaging should usually be recommended instead of CT for imaging of AML during pregnancy in terms of radiation exposure, magnetic resonance imaging was not carried out in the present case, because CT that had already been carried out at the previous hospital gave us sufficient information. Third, the risk of re-rupture during pregnancy should be considered if observation is chosen. Some reports noted that conservative therapy could be managed if maternal and fetal conditions were stable, whereas close follow up and emergency response for re-rupture are required.7 In our review, 14 of 45 cases were treated conservatively. Re-rupture occurred in two cases (14%) during pregnancy. One case had TS. Steiner et al. showed that AML in patients with TS was likely to grow rapidly,8 and might be better treated with TAE than with observation. In the present case, urgent treatment was not required because maternal and fetal conditions were stable. The patient did not have TS, and observation could have been an alternative treatment option when considering fetal radiation exposure. However, there was a risk of re-rupture during pregnancy because of the large size (8 cm) of the AML.9 Yanai et al. suggested the necessity of intervention to prevent AML rupture during pregnancy for patients with AML >4 cm.10 In order to reduce the radiation dose as much as possible, we used low-pulse-rate (7.5 pulses/s) for fluoroscopy and minimal angiography. As their image quality was compromised, color Doppler ultrasonography was used for evaluation of blood flow in the tumor. The fetus was always kept outside of direct radiation. As a result, the radiation dose at the mother’s skin was 13.37 mGy, which was lower than the threshold dose for fetal malformation. The fetal radiation dose was presumed to be much lower than the mother’s. 711
S. MYOEN ET AL.
Fig. 3 Color Doppler ultrasonography before and after the transarterial embolization showing no blood flow in the tumor (arrows).
before
Table 1 Fetal prognosis according to conditions of the mother and fetus at the time of renal AML rupture based on the literature review of 45 cases
after
Conflict of interest None declared.
Conditions of mother and fetus Stable Unstable Unclear
n
Term delivery
Urgent cesarean section
Fetal death
Unclear
22 20 3
20 (91%) 2 (10%) –
0 (0%) 9 (45%) –
0 (0%) 6 (30%) –
2 (9%) 3 (15%) –
When considering the strategy of treatment for ruptured AML during pregnancy, hemodynamic stability of the mother and fetus must be evaluated first. If unstable, active treatment including cesarean section should be carried out immediately to avoid fetal death. If stable, conservative treatment or elective TAE could be selected, depending on the risk of re-rupture, gestational age and estimated exposure dose. When TAE is planned, efforts to minimize fetal exposure should be made. However, TAE cannot always be carried out with negligible dosage, as in the present case. Limitations of procedure time, complexity of the blood stream, low-quality imaging because of low-dose exposure or shielding of the fetus, the positional relationship between the AML and the fetus, and postembolization syndrome could also be associated with success of TAE. It is essential to inform patients of the benefits and risks of each treatment.
712
References 1. Eble JN. Angiomyolipoma of kidney. Semin. Diagn. Pathol. 1998; 15: 21–40. 2. Zapardiel I, Delafuente-Valero J, Bajo-Arenas JM. Renal angiomyolipoma during pregnancy: review of the literature. Gynecol. Obstet. Invest. 2011; 72: 217–9. 3. Komeya M, Matsumoto T, Fujinami K, Senga Y, Asakura T, Goto A. Rupture of renal angiomyolipoma during pregnancy: a case report. Hinyokika Kiyo 2010; 56: 261–4. 4. Ramon J, Rimon U, Garniek A et al. Renal angiomyolipoma: long-term results following selective arterial embolization. Eur. Urol. 2009; 55: 1155–61. 5. Ewalt DH, Diamond N, Rees C et al. Long-term outcome of transcatheter embolization of renal angiomyolipomas due to tuberous sclerosis complex. J. Urol. 2005; 174: 1764–6. 6. Japan Society of Obstetrics and Gynecology, Japan Association of Obstetricians and Gynecologists. Guidelines for obstetrical practice in Japan: Japan Society of Obstetrics and Gynecology (JSOG) and Japan Association of Obstetricians and Gynecologists (JAOG) 2011 edition. J. Obstet. Gynaecol. Res. 2011; 37: 1174–97. 7. Storm DW, Mowad JJ. Conservative management of a bleeding renalangiomyolipoma in pregnancy. Obset. Gynecol. 2006; 107: 490–2. 8. Steiner MS, Goldman SM, Fishman EK, Marshall FF. The natural history of renal angiomyolipoma. J. Urol. 1993; 150: 1782–6. 9. Oesterling JE, Fishman EK, Goldman SM, Marshall FF. The management of renal angiomyolipoma. J. Urol. 1986; 135: 1121–4. 10. Yanai H, Sasagawa I, Kubota Y et al. Spontaneous hemorrhage during pregnancy secondary to renal angiomyolipoma. Urol. Int. 1996; 56: 188–91.
© 2015 The Japanese Urological Association
