CASE REPORT Rupture of renal artery •aneurysms In pregnancy Introduction We present a case of a 35-year-old female who presented at ten weeks gestation with lower abdominal and right flank pain and gross haematu- ria. A preoperative diagnosis of rup- tured right renal artery aneurysm was made with colour Doppler ultrasound and is the first reported case in a preg- nant female. The high maternal and fetal mor- tality of ruptured renal artery aneu- rysm in pregnancy can partly be at- tributed to an incorrect preoperative diagnosis. In only one reported case was a diagnosis made preoperatively using computer tomography (CT) scanning. I Most of the patients were managed as obstetric emergencies with abruptio placentae being the commonest preoperative diagnosis. In addition, hypertension and haematu- ria during pregnancy add to the diag- nostic dilemma.' Recent advances in ultrasound technology have meant that colour Doppler ultrasound can now be used as a quick non-invasive method for assessing the kidneys, re- nal arteries and retroperitoneal spaces. Y Solwa MBChB ZB Bereczky'" MD, FCS(Urol) PCorr FFRadSA J Maharajh FFRad(D)SA C Sanyika FCRad(D)SA Departments of Radiology and Urology·, Faculty of Medicine, University of Natal Medical School Case report A 35-year-old African female, gravida IV, para III, was referred by a 10 SA JOURNAL OF RADIOLOGY- May 1998 general practitioner with a two week history of lower abdominal pain, and frank haematuria. The patient was 10 weeks pregnant. There was no signifi- cant past medical history and her pre- vious pregnancies were all normal. Examination revealed a blood pressure of 150/1 00 mmHg and a pulse of 82 beats/min. The patient had suprapubic and right flank pain on palpation of the abdomen. A bruit was audible on auscultation of the epigas- trium. Catheterisation of the bladder demonstrated frank haematuria with clots. Haemoglobin was 8.4 g/dl and haematocrit was 24.3%. An emer- gency ultrasound examination dem- onstrated a normal, viable intrauter- ine pregnancy and blood clots were noted in the bladder. The left kidney was normal. Examination of the right kidney demonstrated a large 7.3 cm by 5.6 cm hypoechoic lesion in the lower pole (Figure 1a). Colour Dop- pler and duplex Doppler demon- strated extensive blood flow within Figure 1a: Ultrasound of the lower pole of the right kidney demonstrating a 7.3 em by 5.6 em hypoechoie lesion the lesion (Figure 1b). A diagnosis of right renal artery aneurysm was made and arrangements were made to per- form an emergency angiogram. The patient was counselled and agreed to to page 11 Rupture of renal artery aneurysms In pregnancy Figure tb: Duplex Doppler and colour Doppler ultrasound demonstrating extensive blood flow within the lesion have a termination of pregnancy. At angiography, a large saccular aneu- rysm arising from the lower primary division was detected (Figure 2). There did not appear to be any other feeding vessels. In addition, a fistula tract into the right renal vein was noted. Figure 2: Selective arteriogrem of the right renal artery demonstreting a large saccular aneurysm arising from the lower primary division and early venous filling of the renal vein and Inferior vena cava An attempt was made to embolise the feeding artery after discussion with the vascular surgeon. This how- ever, was unsuccessful as the diameter of the artery proved to be much larger than the diameter of the endovascular coil. The coil entered the inferior vena cava via the arteriovenous fistula and lodged in the right lung. The patient was taken to theatre where a right eleventh rib resection was performed and the kidney and its vascular pedi- cle were explored. The feeding artery was mobilised and ligated with silk suture and this resulted in collapse of the aneurysm and disappearance of the bruit. The postoperative period and recovery were uneventful. The patient had a termination of the pregnancy and a follow-up angi- ogram performed two weeks later demonstrated no evidence of the an- eurysm or arteriovenous fistula. Discussion Incidence The true incidence of renal artery aneurysms is still unknown. The inci- dence based on autopsy studies is 0.01 %.3 However, angiographic stud- ies suggest a much higher incidence (9.7%).4,5 In addition, Harrison et al6 reported that 1.5% of all potential kidney donors who underwent angiographic evaluation had renal ar- tery aneurysms. Only 24 cases of re- nal artery aneurysm rupture have been reported in pregnancy (Table I) and a further three cases7,8,9 have been diagnosed post parturn. Aetiology The formation and rupture of a renal artery aneurysm in pregnancy is still not fully understood, but is thought to be multifactorial. The an- eurysm may be classified either as true or false. True aneurysms may be con- genital or acquired and are either sac- cular or fusiform. False aneurysms usually arise secondary to trauma. The combination of hormonal and haemo- dynamic changes that occur during pregnancy are considered to play a 11 SA JOURNAL OF RADIOLOGY. May 1998 major role in the development and rupture of renal artery aneurysms in pregnancy. Wexler" has described the various changes that occur in the arterial wall of breeder rats during successive preg- nancies and Manalo-Estrella and Baker" have documented connective tissue changes in the aortic media of pregnant females in 16 autopsy speci- mens. Intimal thickening has also been seen in the arteries of rats treated with synthetic steroids." Histopathological examinations were conducted on 12 of the 24 cases of renal artery aneurysm that ruptured during pregnancy, Atherosclerosis was demonstrated in three cases, fibro- muscular dysplasia in three cases and neurofibromatosis in one case (Table I), In five cases no specific changes of atherosclerosis or fibromuscular dysplasia were seen. These findings are in contrast to Lacombe's study where 90% of his 123 patients operated for renal artery aneurysms had evidence of fibromuscular dysplasia.P The haemodynamic factors include an in- creased cardiac output and hence in- creased renal blood flow that occurs during pregnancy and compression of the aorta by the gravid uterus." Patient profile and clinical presentation Review of the 24 previously pub- lished cases indicates that there is no relationship between maternal age or parity and the formation and rupture of a renal artery aneurysm in preg- nancy, Only one of the patients was being managed for essential hyperten- sion prior to her pregnancy" and none of the other patients had any signifi- cant medical history. topage12 Rupture of renal artery aneurysms in pregnancy from page 11 This is the second reported case of rupture in the first trimester of preg- nancy" and there appears to be no correlation between fetal gestational age and rupture in this review." Patients with unruptured renal ar- tery aneurysms are usually asympto- matic. Abdominal bruits, murmurs or ab- normal pulsations may occasionally be detected. Calcification is noted in 30 to 40% of saccular aneurysms':" and may be detected on abdominal x-ray. In the presence of a rupture however, acute abdominal and unilateral flank pain to- gether with hypovolaemic shock, appear to be the commonest presenting symp- toms. It is interesting to note that gross haematuria, indicating rupture into the renal pelvis, was the presenting symp- tom in only two other cases.IS,lg Diagnosis The preoperative diagnosis of a ruptured renal artery aneurysm was made in only one of the 24 previously reported cases. I The presence of haemorrhagic shock in the pregnant patient is usually presumed to be due to an obstetric cause such as an ectopic pregnancy, abruptio placentae and rup- tured uterus. This is confirmed by the fact that abruptio placentae was the commonest preoperative diagnosis in the cases reviewed. Rupture of a splenic artery aneu- rysm-? and rupture of a thoracic aorta aneurysm" may also present with spontaneous retroperitoneal and intra- abdominal bleeding and mimic an ob- stetric emergency. The use of pulsed Doppler and col- our Doppler ultrasound to diagnose renal artery aneurysms is well docu- mented.22,23 Colour Doppler ultra- sound provides a quick non-invasive Table I: Reported cases of ruptured renal artery aneurysm in pregnancy Case Authors Year Preoperative Histology no published diagnosis Chisholm AE 30 1926 abruptio placentae none 2 Ostling K 31 1938 not stated non specific 3 Lennie & Sheehan 32 1942 not stated atherosclerosis 4 Lennie & Sheehan 32 1942 not stated none 5 Low DM 33 1944 ruptured uterus none 6 Kenny & Doniach 34 1945 not stated none 7 Zummo et al20 1952 abruptio placentae none 8 Hack RW3s 1953 left pyelonephritis atherosclerosis 9 Ward & Martins 36 1955 not stated none 10 Burt RL et a/37 1956 not stated atherosclerosis 11 Tapp & Hickling 36 1968 ruptured aortic artery neurofibromatosis aneurysm 12 Thomas & Gillis 39 1970 ruptured uterine none artery 13 Cohen SG et al ,g 1972 not stated non specific 14 Patterson WM 40 1973 abruptio placentae non specific 15 Saleh & McLead 41 1977 not stated fibromuscular dysplasia 16 Love WK et a/2' 1981 abruptio placentae none 17 Barrett JM et a/42 1981 ?ruptured renal artery non specific aneurysm 18 Hidai H et a/43 1985 ectopic pregnancy fibromuscular dysplasia 19 Cohen & Shamash 4' 1987 abruptio placentae none stated 20 Schoon 1Met al2s 1988 abruptio placentae non specific 21 Dayton B et a/ 1 1990 ruptured Rt renal artery none aneurysm post arteriography 22 Murakami M '5 1993 not stated 23 Whiteley MS et a/'6 1994 ruptured ectopic none pregnancy 24 Rijbroek A et al 15 1994 not stated fibromuscular dysplasia 25 Current study 1997 ruptured Rt renal artery none aneurysm method of assessing the kidneys, re- The management of an unruptured nal arteries and retroperitoneal spaces renal artery aneurysm in pregnancy or and should be used more routinely in in the woman of child-bearing age who the pregnant female who presents in may become pregnant is elective sur- haemorrhagic shock. gery because of the increased risk of Treatment rupture with potentially fatal conse- quences. The management differs how- Because of the late diagnosis of ever, in the nonpregnant patient. Con- rupture in the antepartum period, 10 servative management for calcified re- nephrectomies were performed in the nal artery aneurysms less than 1.5 cm 24 caseswe reviewed. In only four cases in diameter in the asymptomatic, was repair of the renal artery per- nonhypertensive patient has been formed. I,I6,24 ,2S to page 13 12 SA JOURNAL OF RADIOLOGY· May 1998 Rupture of renal artery aneurysrns In pregnancy from page 12 recommended.26,27,28 Indications for surgery include renovascular hyper- tension, flank pain attributable to the aneurysm, haematuria, aneurysm more than 2 cm in size (with or with- out calcification) ,renal infarction and lack of calcification in an aneu- rysm.27,29 When elective surgery is performed, kidney sparing procedures are recommended. These would in- clude excision of the aneurysm and primary or patch closure. Autotrans- plantation and bypass grafting are other options that are available. Conclusion Since Chisholm" reported the first case of rupture of renal artery aneu- rysm in pregnancy, 23 other cases have been published. The high maternal and fetal mortality rates have mainly been due to incorrect preoperative diagnosis, with most cases being man- aged as obstetric emergencies. We have provided the first case in which colour Doppler ultrasound was used to make a preoperative diagnosis and recommend its routine use in assess- ing the pregnant patient who presents with gross haematuria, acute flank pain and haemorrhagic shock. References 1. Dayton B, Helgerson RB, Sollinger HW, Acher Cw. Ruptured renal artery aneurysm in a pregnant uninephric patient: successful ex vivo repair and autotransplantation. Surgery 1990 Jun; 107 (6): 708·11. 2. Klimberg 1, Wilson J, Davis K, Finlayson B. Haemorrhage from congenital arteriovenous malformation in pregnancy. Urology 1984; 23: 381-4. 3. 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