A critical look at the treatment of maxillary sinusitis with long-term draining tubes.

Long-term draining tubes (LTD) have become a common treatment in complicated and prolonged forms of maxillary sinus empyema. Since not all patients show good recovery with this treatment we used sinus-manometry, mathematical calculations, and scanning electron microscopy (SEM) to critically analyze 6 cases with a prolonged history of the disease. Five out of the 6 patients recovered quickly after removal of the LTDs, normally performed sinus punctures, and an appropriate antibacterial treatment. One patient underwent functional endoscopic sinus surgery. Two of the 6 patients had uncommon bacterial cultures (Pseudomonas mirabilis, Klebsiella oxytoga) in their sinus secreta. Two of the removed LTDs were examined with SEM. The porous polyethylene was shown to have absorbed bacterial plague which, besides narrowing the lumen, can cause recurrent infections. In 5 other patients, the draining pressure (DP) was 0.9 +/- 0.16(M +/- SD) kg/cm2, as measured during irrigation with a No. 2 Lichtwitz needle (1.8 mm, i.d). Mathematical calculation using the Hagen-Boisseouille equation indicated that with our LTDs (0.7 mm, i.d.) the DP needs to be 40 times greater than the DP when using an ordinary Lichtwitz needle to get equal flushing capacity. We recommend i) LTD treatment of maxillary sinus empyema be closely followed up ii) that, in prolonged cases, the LTDs should be removed and the sinuses repeatedly irrigated with an ordinary needle or antrostomy, and iii) that a more suitable tubing material and insertion system (to allow a larger radius of the tube) be developed.