Sternal elevation by the crane technique during pectus excavatum repair: A quantitative analysis

Abstract

Introduction

The crane technique is used to facilitate sternal elevation to provide safe mediastinal passage during the Nuss procedure. The aim was to objectively quantitate the elevation of the crane by 3-dimensional chest images acquired during the Nuss procedure.

Methods

A prospective cohort study was conducted. Patients undergoing the Nuss procedure were eligible. Sternal elevation was achieved by the crane technique providing a simultaneous lift of the anterior chest wall and reduction of the pectus excavatum depth. Both effects were evaluated. Three-dimensional surface images were acquired before incision, following sternal lift, and after bar implantation and quantitatively compared. Reduction of the external pectus excavatum depth was expressed as a percentage.

Results

Thirty patients were included. Ninety percent were male, with a median age of 15.5 years (interquartile range [IQR], 14.5-17.4), Haller index of 3.56 (IQR, 3.09-4.65), and external pectus depth of 18 mm (IQR, 11-23). Sternal elevation by the crane provided a median 78% (IQR, 63-100) reduction of the deformity, corresponding with a residual depth of 3 mm (IQR, 0-7). The percentual reduction diminished with increasing depth of the sternal depression (correlation, –0.86). Besides reducing the deformity, the crane caused an elevation of the anterior chest over a large surface area with a maximum lift of 26 mm (IQR, 19-32).

Conclusions

The crane is an effective sternal elevation technique, providing 78% reduction of the sternal depression, although its effect lessens with increasing depth. In addition, it produces an elevation of the anterior chest over a large surface area.

Graphical abstract