# Validation of a laser projection platform for the preparation of surgical patches used in paediatric cardiac surgery

## TL;DR

A laser projection system was validated as a promising alternative to traditional templates for creating surgical patches in pediatric heart surgery.

## Contribution

The study introduces and validates a laser projection platform for intraoperative, patient-specific surgical patch preparation.

## Key findings

- Laser projection dimensions were within 5% of control measurements, showing high accuracy.
- The laser method outperformed traditional templates in dimensional consistency.
- Feasibility was confirmed across various patch materials and sizes.

## Abstract

Reconstruction of cardiovascular anatomy with patch material is integral to the repair
of congenital heart disease. We present validation of a laser projection platform for
the preparation of surgical patches as a proof-of-concept for intraoperative use in
patient-specific planning of paediatric cardiac surgery reconstructions.

The MicroLASERGUIDE, a compact laser projection system that displays computer-aided
designs onto 2D/3D surfaces, serves as an alternative to physical templates. A
non-inferiority comparison of dimensional measurements was conducted between laser
projection (‘laser’) and OZAKI AVNeo Template (‘template’) methods in creation of 51
(each group) size 13 valve leaflets from unfixed bovine pericardium. A digital version
of the OZAKI AVNeo Template dimensions served as control. Feasibility testing was
performed with other common patch materials (fixed bovine pericardium, PTFE and porcine
main pulmonary artery as a substitute for pulmonary homograft) and sizes (13, 23)
(n = 3 each group).

Compared to control (height 21.5, length 21.0 mm), template height and length were
smaller (height and length differences of −0.3 [−0.5 to 0.0] and −0.4 [−0.8 to −0.1] mm,
P < 0.01 each); whereas, both laser height and length were
relatively similar (height and length differences of height 0.0 [−0.2 to 0.2],
P = 0.804, and 0.2 [−0.1 to 0.4] mm, P = 0.029).
Template percent error for height and length was −1.5 (−2.3 to 0.0)% and −1.9 (−3.7 to
−0.6)% vs 0.2 (−1.0 to 1.1)% and 1.0 (−0.5 to 1.8)% for the laser. Similar results were
found with other materials and sizes. Overall, laser sample dimensions differed by a
maximum of 5% (∼1 mm) from the control.

The laser projection platform has demonstrated promise as an alternative methodology
for the preparation of surgical patches for use in cardiac surgery. This technology has
potential to revolutionize preoperative surgical planning for numerous congenital
anomalies that require patient-specific patch-augmented repair.

Reconstruction of cardiovascular anatomy with patch material is an integral component of
surgical repair for congenital anomalies including aortic valve (AV) disease, Tetralogy of
Fallot, atrioventricular septal defects, total anomalous pulmonary venous return,
intracardiac baffles and hypoplastic or interrupted aortic arch [1–6].