Bowel protection achieved by percutaneous fine needle deflation during percutaneous renal tumor cryoablation: A case report.

Purpose
To report a case of Colon protection during CT-guided percutaneous renal tumor cryoablation achieved by percutaneous fine needle deflation.
Materials and Methods
A 56-year-old male presented with microhematuria and a 2.8 cm right kidney upper pole mass abutting the right hepatic lobe and ascending colon for CT-guided biopsy and cryoablation. Under general anesthesia, three cryoablation probes were successfully placed into the mass percutaneously followed by a core needle biopsy. Four 21G Chiba needles were advanced into the spaces between the right hepatic lobe / ascending colon and the renal mass to perform hydrodissection and pneumodissection. Successful displacement of the right hepatic lob away from the renal mass was obtained with initial dissection. However, the displacement of the ascending colon was inadequate due to the severely dilated colon. A 22G spinal needle was then advanced into the adjacent ascending colon percutaneously to deflate the colon by aspirating approximately 40ml bowel gas. Cryoablation was then performed with intermittent hydro- and pneumo- dissection. A total of 800 ml diluted contrast and 800ml CO2 were used for dissection.
Results
Adequate displacement of the ascending colon from the renal mass was obtained after the fine needle deflation and the following hydro- as well as pneumo- dissection. Post-procedure immediate CT scan demonstrated the ice ball covering the whole renal mass with a small hematoma, and no evidence of colon perforation. The patient was discharged home within 24 hours. The post-ablation course was uneventful except for low-grade fever and moderate right flank pain for 5 days. Follow-up CT with IV contrast 2 days post-procedure revealed no enhancement of the renal mass without evidence of active bleeding or abscess, nor other acute complications.
Conclusion
Percutaneous fine needle deflation of the dilated bowel may be a safe and effective technique for bowel protection during renal tumor thermal ablation when failed initial hydro- or pneumo- dissection.