Case of the week Details

• Severe left hydronephrosis with significant renal parenchymal thinning (Fig.1a) Gravid Uterus with a single intrauterine fetus, normal placenta for age and normal fetal parts.
• Left perinephric urinoma with large acute to subacute hematoma and apparent breach of posterior pyelo-parenchymal junction (red arrow in Fig.2a and 3a). Fluid seen in the left posterior peri-renal space tracking along the left para-spinal muscles and posterior abdominal wall (green arrows in Fig.3a).
• Mild ascites with mild to moderate left pleural effusion (Fig.4a)
• Interval resolution of hydronephrosis and significant reduction of perinephric urinoma post DJ stenting and PCN (Fig.5a and 6a).

Diagnosis:
Spontaneous perinephric urinoma with intrarenal hematoma in pregnancy.

Discussion:

• Urinoma is a continued perinephric or peripelvic extravasation of urine leading to the formation of an encapsulated retroperitoneal urine collection.
• Trauma or surgery to the ureter, infection and nephrolithiasis are known causes of non-obstetric urinoma.
• Spontaneous maternal urinoma is a rare complication of hydronephrosis even in a normal kidney during pregnancy.
• Maternal urinoma is thought to develop secondary to the rupture of the calyceal fornix. It occurs when renal pelvis pressure exceeds a critical level between 70 and 75 mmHg due to ureteral or renal compression and often presents with hematuria.
• Ureteral stent placement is an essential treatment for maternal urinoma as ureteral compression by gravid uterus is the underlying pathophysiology.
• This case was unique in that the patient had a solitary left kidney with congenital PUJ with a functioning pyeloplasty prior to pregnancy, but developed a spontaneous urinoma with anuria and rising Serum creatinine at 25 weeks.
• The patient underwent rapid percutaneous nephrostomy and ureteral stenting resulting in rapid decline in elevated creatinine and a decompressed left kidney as seen in follow up Ultrasound images.

REFERENCES/ FURTHER READING:

1. Chen, Y., Yan, Y.F., Zhang, Y. et al.Perinephric urinoma following spontaneous renal rupture in the third trimester of pregnancy: a case report and brief review of the literature. BMC Pregnancy Childbirth 19, 505 (2019).
2. Ushioda, N., Matsuo, K., Nagamatsu, M., Kimura, T., & Shimoya, K. (2008). Maternal urinoma during pregnancy. Journal of Obstetrics and Gynaecology Research, 34(1), 88–91.
3. Hamoud, K., Kaneti, J., Smailowitz, Z. et al. Spontaneous perinephric urinoma in pregnancy. International Urology and Nephrology 26, 643–646 (1994).
4. Mandal D, Saha MM, Pal DK. Urological disorders and pregnancy: An overall experience. Urol Ann. 2017;9(1):32-36.

Dr. Sunita Gopalan
DMRD, FRCR
Senior Consultant Radiologist
Manipal Hospitals Radiology Group.

Dr. Suvarna Kote
Radiology resident- Manipal Hospitals Radiology Group.