Case Study - November 2010
A 34 year old lady who was 26 weeks pregnant presented to the maternity unit with a 5 day history of gradual onset right loin pain. Her right loin pain worsened over a period of a few hours and an urgent ultrasound of the kidneys was arranged.
- What does the above ultrasound images show?
- What are the causes of this condition?
- What is the pathophysiology of pregnancy associated hydronephrosis?
- How would you manage this patient?
Reveal Answer
Open answer There is no fixed answer to this question, however your response should be similar to the one below:
- The ultrasound shows bilateral hydronephrosis. There is evidence of partial decompression of the right kidney with a large hypoechoic area seen around the right kidney and ureter. The appearances are suggestive of fluid around the right kidney and ureter and given the partial decompression of the right kidney, the appearances are likely to be that of an urinoma.
- Causes of acute hydronephrosis during pregnancy include physiological pregnancy associated hydronephrosis, urolithiasis or obstruction along the urinary tract. This patient was noted to have a large intrauterine fibroid which is causing mechanical blockage of both her ureters.
- May be due to ureteral smooth muscle relaxation in response to high levels of circulating progesterone during pregnancy. May also be due to mechanical compression of the ureters by the enlarging uterus at the level of the pelvis brim where the ureters cross the iliac vessels. Note that hydronephrosis during pregnancy is often worse on the right side because of pressure due to physiologic engorgement of the right ovarian vein and dextrorotation of the uterus.
- Primary management should be to relieve pressure and allow temporary diversion of urine by insertion of bilateral nephrostomy tubes or bilateral retrograde JJ stents. Nephrostomy insertion in this patient would be difficult as the right kidney is already partially decompressed, therefore cystoscopy and bilateral retrograde JJ stent insertion would be the preferred management choice. Careful consideration needs to be given to the risk to the unborn baby due to the use of anaesthetic agents and radiation exposure during JJ stent insertion.
Ultrasound image of left ureteric stent placement performed under U/S guidance alone.
