3D Printing as a Planning Tool to Optimize Sinonasal Irrigation

Topical sinus irrigation plays a critical role in the management of sinonasal diseases. Yet, the penetration of irrigant to targeted sinuses may be highly variable and difficult to predict. Here, we investigate the use of 3D printing as a planning tool to optimize outcomes.

Eight post-operative models were 3D printed with a FormLabs Form3 printer based on individual CT scans. Irrigations were performed and video recorded with a squeeze bottle attached via silicon water-tight seal, in 4 head positions: 45° to-the-side, 90° to-the-side, 45° forward and 45° to-the-side, and 90° forward, with irrigation fluid entering the upper (conventional) or lower (backfill) nostrils.

Significant individual variations were observed in sinus penetration as a function of head position. In general, the maxillary sinus was the easiest to irrigate in most head positions (P < .05), followed by frontal and ethmoid, with sphenoid being the most difficult. Both the 90°-to-the-side and the 90°-forward positions were significantly more effective than the others (P < .05), with 90°-forward better for frontal sinuses and 90°-to-the-side superior for all other sinuses. The backfill was significantly superior to conventional technique in head positions involving a side tilt (P < .05).

Variations in technique and position significantly impacted irrigation outcome. Backfill irrigation that pushes fluid against gravity to pool around the ostium, seems to provide overall better outcomes. This study demonstrates the advantage of 3D printing as a rapid planning tool to guide irrigation strategies.