# Penetrating thoracic stab wounds and the cardiac box: a single-center experience of in-hospital treatment and outcome in Germany

## TL;DR

This study examines the treatment and outcomes of thoracic stab wounds in a German trauma center, finding that injuries outside the cardiac box can also be serious.

## Contribution

The study evaluates the clinical relevance of the cardiac box concept in predicting thoracic stab wound severity.

## Key findings

- Injuries within the cardiac box had higher injury severity scores but similar hemodynamic parameters.
- Major complications were more frequent in the cardiac box group compared to those outside.
- The cardiac box concept may be too simplistic as significant injuries can occur outside this area.

## Abstract

Thoracic stab injuries (TSI) are rare but potentially life-threatening emergencies. In Germany, their incidence in emergency departments remains low. The cardiac box (CB) concept has been proposed to identify cardiac involvement in penetrating thoracic trauma, although its clinical relevance remains uncertain. This study aimed to evaluate the in-hospital management of TSI and to assess the predictive value of the cardiac box for major intrathoracic injuries.

A retrospective and exploratory analysis was conducted of all patients with TSI resulting from assault or self-harm who were admitted to a certified Level 1 trauma centre between January 2020 and June 2024. Prehospital and in-hospital variables were descriptively analysed.

Fifty-six male patients were included (median age 28.5 years). Sixteen patients sustained injuries within the cardiac box (CB), and thirty-nine outside this area (NCB). All CB patients (100%) and 95% of NCB patients were admitted via the emergency department. The annual proportion of thoracic stab injuries among all emergency presentations ranged from 1.4% to 2.4%.

The median Injury Severity Score (ISS) was significantly higher in the CB group (9.5 vs 3; p = 0.045), whereas the distribution of intrathoracic injury types and initial haemodynamic parameters (MAP CB: 93 mmHg vs NCB: 97 mmHg; p = 0.925) did not differ significantly. Two patients in the CB group had a cardiac and/or great vessel injury. Two NCB patients received prehospital chest tubes. In the emergency department, chest tubes were placed in 23.2% of patients, with no significant group difference. Median intrahospital transfer time to the target department was shorter in CB patients (38 vs 67 min).

Video-assisted thoracic surgery (VATS) was performed in eight patients (CB: 25%; NCB: 10.3%; p = 0.241), and one open procedure was undertaken in each group. Major complications (Clavien–Dindo ≥ II) occurred more frequently among CB patients (50.1% vs 25.7%; p = 0.018). The overall mortality rate was 3.6% (two CB patients).

TSI are rare but serious injuries requiring structured, multidisciplinary in-hospital management. Minimally invasive approaches are feasible in haemodynamically stable patients. The low rate of prehospital chest tube placement warrants further evaluation. The cardiac box concept appears overly simplistic, as clinically significant injuries may also occur outside this anatomical region.

The online version contains supplementary material available at 10.1186/s13049-026-01555-y.