[Rupture of renal arterial aneurysm in a pregnant patient]

The author experienced a case of ruptured renal arterial aneurysm diagnosed at 32 weeks of gestation. The patient was a 32-year-old healthy woman. On admission she and her fetus were in pre-shock state. Emergency caesarean section was performed under spinal anesthesia. Postoperative CT scanning revealed the ruptured right renal artery aneurysm and hematoma around the right renal hilus. About 7 hours after caesarean section, laparotomy was performed for right nephrectomy and subtotal hysterectomy. Blood loss during operation was about 8000 ml, but postoperative course was good and she and her baby had no complications. It is suggested that arterial wall of pregnant woman has weakness due to morphological and biochemical alterations following hormonal change. Pregnant uterine compresses and dislodges abdominal aorta and inferior vena cava, and these vessel moves in a curve in a leftword and dorsal direction. Plasma volume increases in late pregnancy, therefore intra-arterial pressure is elevated. It is proposed that alterations of vessel wall, increases of circulatory blood volume and vessel displacement are implicated to the etiology of renal arterial aneurysm of pregnant woman. Pregnancy-related renal arterial aneurysm has a high risk of rupture and it is advisable to think of ruptured renal arterial aneurysm as one of the causes of hemorrhagic shock during pregnancy.