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"Superior tubing was accessed with a needle and contrast injected to confirm intraluminal position and patency of the superior tube. Contrast was noted to pass freely into the right atrium (49427, 75809). Thus, the issues with the indwelling Denver shunt was most likely at the valves between the reservoirs and between the superior reservoir and superior tubing. Utilizing a total 6mg in 6 mL of tPA, cytology brush, and glidewire, mechanical debridement along with aspiration of the inferior reservoir yielded a small volume of debris with subsequent passage of contrast from the inferior reservoir to the superior reservoir. Additional mechanical debridement along with aspiration of the superior reservoir didn't result in passage of contrast from the superior reservoir to the superior tubing despite multiple attempts."  Can the mechanical debridement be coded as 49426? Or do I need to go unlisted?