CT-guided nephrostomy-An expedient tool for complex clinical scenarios.

INTRODUCTION & OBJECTIVES: Percutaneous nephrostomy [1] has emerged as a pivotal approach in the therapeutic management of the obstructed urinary tract. A consecutive incorporation of ultrasonic and radiographic guidance, the approach experienced an almost ubiquitious distribution while most centers currently applying either one or both of these tools jointly. However, success of ultrasound-guidance is limited in obese patients and non-dilated uropathy. In turn, fluoroscopy usually requires an opacification of the urinary collecting system by intravenous or antegrade contrast media injection, which might be harmful for already impaired renal function, raise intrapelvic pressure and augment the risk of sepsis and hemorrhage. CT-guided PCN aids in overcoming these limitations. In the current study, we present the experience of a tertiary referral center with this technique.

MATERIALS & METHODS: Epidemiological and clinical data of all patients treated with a CT-guided PCN of native kidneys at the University Hospital Frankfurt between October 2003 and October 2013 were retrospectively collected from the patient charts. Procedural parameters including radiological aspects, technical and therapeutic success, complication and mortality rate have been analyzed statistically.

RESULTS: In total, 140 PCN procedures have been performed in 77 patients with a median age of 69 (± 13). The median body mass index was 27 with 66.6% of patients being overweight or obese. Charlson comorbidity index was 7 ranging 0-16. Indications for PCNs were obstructive uropathy (62.9), urine extravasation (22.9%), urinary tract fistulas (11.4%) and technical reasons (2.8%). In 68.8% of patients, initial diagnosis was malignancy. 56.4% of kidneys were non-dilated before puncture. In 78.4% prone position, otherwise supine oblique position (17.3%) or supine position (4.3%) was used. 71.4% of PCNs were carried out solely under local anesthesia. Technical success has been achieved in 90% with a complication rate of 3.6% (all grade minor B) and was not significantly different between dilated and non-dilated kidneys. 42.9% of fistulas and 64.3% of urinary tract leakages, healed after PCN placement. 30 days mortality rate was 5.2% without being directly associated with the PCN procedure itself.

CONCLUSION: CT-guided PCN is a feasible approach associated with low morbidity. It is particularly useful in complex clinical scenarios e.g. critically ill, newly operated or obese patients as well as non-dilated kidneys. Moreover, it represents a minimally-invasive option for treating leakages and fistulas of the urinary tract.