Prevertebral Soft-tissue Swelling Following One-level Anterior Cervical Discectomy and Fusion: An Analysis Based on Surgical Level.

Background: The purposes of this study were to identify the primary level at which PSTS occurs following one level anterior cervical discectomy and fusion (ACDF) based on surgical level, and to quantify the degree to which it occurs. Although prevertebral tissue swelling (PSTS) peaks at day 2 or 3 after ACDF, with swelling noted to be prominent at levels C2-4, the way in which the features of PSTS vary according to surgical level has not been examined.

Methods: 37 patients who underwent one-level ACDF were reviewed and classified into retropharyngeal and retrotracheal group based on surgical level. PSTS occurring at C2-C6 and the width of airway (WA) at C2-C4 was assessed using plain radiographs before surgery and at 1, 3, 5, and 7 days postoperatively.

Results: The retropharyngeal group comprised 10 patients while the retrotracheal group comprised 27 patients. Retropharyngeal group had the most severe PSTS on day 3 after surgery. C4 showed PSTS peaked on day 3, with a value of 3.26 times the preoperative prevertebral tissue thickness. WA at C4 was narrowest on day 1, with a value of 0.74 times and remained narrow until day 3. The retrotracheal group showed the most severe PSTS on day 1 at level C3:2.81 times. WA at C4 was narrowest on day 1 with a value of 0.78 times and increased thereafter.

Conclusions: PSTS following one-level ACDF for both retropharyngeal and retrotracheal lesions was greatest at the C3 and C4 levels, with peaks on the third day after operation for the former, and the first day for the latter. WA at C4 was narrowest from day 1 in both groups. In the retrophyaryngeal group, narrowing remained until day 3.