Late-Onset Inflammation in Asian Rhinoplasty Using Alloplastic Implants.

Background: Late-onset inflammation is a rare complication that may occur several months to years after undergoing an uneventful rhinoplasty using alloplastic implants and an uneventful postoperative course. Studies to determine the pathophysiological mechanisms of late-onset inflammation related to implants used in rhinoplasty are limited. The purpose of the study was to analyze differences between non-healthy capsules (NHC) with late-onset inflammation and healthy capsules (HC) without inflammation as controls to determine the possible cause of the inflammation.

Methods: Between April 2009 and May 2018, 39 patients who underwent rhinoplasty with alloplastic implants underwent histological studies. Twenty-one patients in the NHC group showed late-onset inflammation, while 18 patients in the HC group did not display late-onset inflammation. Capsules around the alloplastic implants were harvested, and histological studies using hematoxylin and eosin, Masson's trichrome, colloidal iron, and CD31 staining were performed and compared between the NHC and HC groups.

Results: In hematoxylin and eosin and Masson's trichrome staining, edematous granulation tissues, inflammatory cellular contents, and a disorganized collagen layer were increased in the NHC group compared to the HC group. The colloidal iron staining revealed mucin deposition in the NHC group. CD31-positive cells were observed lining the capsule in both groups; however, the lining cells were damaged in the NHC group.

Conclusion: Granulation tissues, inflammatory reaction, collagen degeneration, mucin deposition, and endothelial lining cell damage were greater in the NHC group compared to the HC group. Damaged capsules may play a crucial role in late-onset inflammation.

Level Of Evidence Iv: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .