Preoperative Metal Patch Testing and Titanium Bar Use Criteria in Nuss Procedure: A 56-Patients' Cohort Study

Abstract

Introduction: Nuss procedure is the main reason for metal implants use by pediatric and thoracic surgeons. There is an ongoing debate on how to avoid allergic complications. Herein we describe our eight-year experience with systematic preoperative metal patch testing and our selective titanium bar use in Nuss procedure. Materials and Methods: Single center retrospective observational cohort study of patients who underwent the Nuss procedure from 2013 to 2020. Preoperative metal patch testing was done in all cases. Criteria for titanium bar utilization were: a positive test for a major component of the stainless-steel bar; or a positive metal patch test and a positive history of atopy, food or metal allergy, or previous allergic reaction to an implant or device. Results: 56 patients were included. Most were male (91.1%) with a median age of 15.0 [13.0-22.0] years old. 19.6% had a positive preoperative metal patch test and 54.5% of these had no personal history of atopy. Stainless-steel bars were used in 27.3% of those patients and titanium bars were used in 72.7%. One patient had a documented minor allergy reaction. None of the 56 patients required early bar removal. Conclusions: Our study suggests that routine preoperative allergy testing and a judicious use of titanium bar is safe and avoids metal allergic complications.

The contribution of metal allergy to the failure of metal alloy implants, with special reference to titanium: Current knowledge and controversies

“…32 Routine pre-operational 'predictive' patch testing or LTT is not generally recommended, the exceptions being the stipulation by maxillo-facial surgeons for this prior to the insertion of replacement temporo-mandibular joints 67 and, according to guidelines of the American Contact Dermatitis Society, prior to the Nuss procedure for correction of pectus excavatum using either a stainless steel or a titanium alloy bar. 68 However, it would not be surprising if more institutions were to recommend predictive patch testing, considering the medico-legal milieu of many societies, despite the drawbacks of the procedure-principally on interpretation, plus false negatives and false positives, but also persistent patch test reaction, for example if gold salts are tested. Nonetheless, for patients with failing metal articulated prostheses, especially if blood levels of metal ions are elevated, patch testing or LTT are indicated (guided by clinical history) to inform clinicians of how to best to manage the case.…”