The use of ultrasound contrast agent in ultrasound guided percutaneous nephrostomy

Purpose: The aim of the study was to evaluate the usefulness of ultrasound contrast agent (UCA) in ultrasound (US) guided percutaneous nephrostomy (PCN) and assessing complications.

Patient and methods: 45 US guided PCN were performed in 35 patients (age 69 ± 12 [38 – 91] years, 26 males and 9 females) with hydronephrosis due to urinary tract obstruction. UCA (0.1 ml of SonoVue® diluted in 20 – 30 ml saline) was injected into the renal collecting system to confirm the correct needle or catheter insertion and determine the site and degree of the obstruction, using fluoroscopy as the gold standard. Extravascular contrast enhanced ultrasound (EV-CEUS) was performed again on the following day to assess complications.

Results: All 45 PCN were successfully performed under the guidance of US. After the UCA was injected into the catheter, the site and degree of the obstruction could be clearly shown with EV-CEUS in all 35 patients compared with fluoroscopy. After the site of obstruction was defined, EV-CEUS showed double kidneys in 2 patients, ureteral stones in 4 patients and abdominal focal lesions that compress or block ureter in 19 patients. Catheter dislodgement was diagnosed by administration of UCA in 5 patients, and required re-insertion of the catheter. Hematoma (1 patient) and urine leakage (1 patient) were also found.

Conclusions: Due to the advantages of US, such as safety, no radiation, real time, bedside availability and time-saving, the combination of UCA and PCN may become a new diagnostic and therapeutic method for clinical use in urology.

Key words: Percutaneous nephrostomy, ultrasound, microbubbles, kidney, complication