[A contribution of multidetector computed tomography to indications for chest wall stabilisation in multiple rib fractures].

PURPOSE OF THE STUDY

Multidetector computed tomography (MDCT) is more sensitive for the detection of injury to the thoracic wall and intra-thoracic organs than a plain chest radiograph. The chest wall deformity and instability following multiple rib fracture involves fractures of four or more adjacent ribs at two levels, sometimes including a sternal fracture. It may also be associated with lung trauma (pneumothorax, haemothorax, rupture, laceration or pulmonary contussion). An isolated multiple-rib fracture can successfully be treated conservatively. Early intubation and mechanical ventilation are indicated in patients with progressive respiratory insufficiency. Indications for surgical stabilisation of this fracture are based on the signs of respiratory failure and the results of imagining methods (MDCT at the present time).

MATERIAL AND METHODS

Examination by MDCT was carried out in patients with severe thoracic trauma. In five patients with multiple rib fractures, the CT findings were included in indication criteria for open rib osteosynthesis and thoracotomy. A clinical indication criterion was respiratory insufficiency after the patient's weaning from a ventilator, manifested by paradoxical chest motion. A radiographic indication included an extensive chest deformity with rib displacement into the pleural cavity in 3D reconstruction from MDCT images. Surgery was performed within one hour to five days of admission. Access was gained through an oblique skin incision and by cutting though the chest wall muscles to release fractured ribs. To explore the thoracic cavity, a defect in the intercostal muscles was extended by an incision at the site of rib fracture. Suction of a haemothorax was done and lung ruptures were sutured in three patients. After chest drain insertion, the fractured ribs were stabilized by plate osteosynthesis (fy Medin).

RESULTS

In the post-operative period, mechanical ventilation was continued for 3 to 6 days in four patients. There were no complications. In the patients with flail chest, the 3D reconstruction from MDCT images allowed us to make more exact pre- operative decisions concerning the extent of rib osteosynthesis and the method of exposure. If lung injury was also shown, this was an indication for thoracic cavity exploration.

DISCUSSION

The pathophysiological effects of flail chest involve several factors including the size of a flail segment, change in intra-thoracic pressure during spontaneous breathing and multiple injuries to the intra-thoracic organs. Therapy is related to the seriousness of respiratory disorder associated with flail chest, the degree of chest wall deformity and other complications of conservative treatment (dependence on mechanical ventilation with no possibility of weaning). Surgical stabilization of the chest wall is the most reliable method of treatment which allows us to avoid or interrupt the adverse effect of rib displacement and chest instability. A contribution of MDCT examination to the indication for surgical stabilization lies in that MDCT provides imagining of the details decisive for the classification of fracture types including their tendency to displacement. MDCT permits a better visualisation of chest injury and a better understanding of the respiratory disorder.

CONCLUSIONS

Based on 3D reconstruction from MDCT images, it is possible to make the pre-operative considerations for rib osteo- synthesis more specific and to choose the best approach. At the same time MDCT enables us to diagnose associated intra-thoracic injuries and provides indications for their treatment. In addition, it gives us a possibility to evaluate the role of a flail segment in breathing dysfunction and to establish indications for surgical stabilization in multiple rib fractures. Rib osteosynthesis allowed for early stabilization of the chest wall and improved the mechanics of breathing, thus requiring a shorter period of mechanical ventilation. The evaluation of statistical significance of these facts will be made when a larger group of patients examined by MDCT is available.