In this observational retrospective cohort study, we describe the characteristics, the management and the outcomes of 42 patients referred to the ICU of a referral thoracic center for surgical rib fracture fixation after a severe chest trauma, using the titanium plate of the Stracos™ system.
Our cohort is original, as it included different patients than those described in previous randomized controlled trials [14,15,16] (Additional file 1: Table S3). This was a selected population of patients transferred from trauma center with only isolated chest trauma. Our patients had more domestic accidents, were older, and had no respiratory failure in two third of the cases.
Postoperative complications occurred in 18 patients (43%) including two ICU deaths. This high rate of postoperative complications may question the role of surgery in such a selected population, particularly in old patients with severe trauma. The formalized experts French guidelines published in 2015 and 2017 recommend surgical rib fixation «in mechanically ventilated patients if the respiratory condition does not allow weaning from mechanical ventilation within 36 hours of admission», on the basis of three small size randomized clinical trials, two of which no longer reflect current practices [14,15,16].
These results are confirmed by more recent retrospective series, where operative rib fixation has the potential to reduce ventilator days and ICU stay in selected patients with severe traumatic flail chest requiring mechanical ventilation .
The radiological severity (flail chest) of the chest trauma may out weight the clinical and respiratory status of the patient in the surgical decision. However, the benefit of SRFF in non-ventilated patients remains to be determined. In a recent case–control series involving non-mechanically ventilated patients with flail chest, the patients who were treated non-surgically had better outcomes than their counterparts, with shorter duration of mechanical ventilation, lower rate of post-operative pneumonia and shorter ICU and hospital lengths of stay . One of the main expected benefits of surgery is to decrease the duration of mechanical ventilation and reduce the associated morbidity. By restoring parietal rigidity, better wall mobility should be achieved, facilitating the restoration of proper ventilation. However, this hypothesis has not been confirmed in any controlled trial, and large variations in the duration of mechanical ventilation have been reported [15,16,17]. In the most recent series by Marasco et al.  the duration of mechanical ventilation was similar in the surgical group (6.3 days ± 3.4), as compared with the conservative group (7.5 days ± 5.4). Several hypotheses may explain the lack of benefits of surgery on the duration of mechanical ventilation. First, the chest wall mobility restoration and the expected better pulmonary compliance could be insufficient, due to the rigidity of the material used. In our series, the titanium claw plates were used. These clips simplify the fixation of screwless plates but there is no evidence that they may reduce the risk of intercostal neurovascular damage. Second, the surgical procedure itself may be more deleterious than beneficial. The complications associated with selective intubation [23, 24], one-lung ventilation, lateral decubitus positionning [25, 26] and the consequence of perioperative fluid administration and transfusion must be weighed against the expected advantages of surgery. A muscle-sparing approach, less invasive than posterolateral thoracotomy, could be considered as suggested in a recent series . Data from the literature on other postoperative respiratory outcomes are unclear. The incidence of ARDS is not known but it increases with the number of fractured ribs . Its incidence has decreased since the introduction of protective ventilation . Postoperative pneumonia is not clearly defined in the literature and its incidence varies from 10 to 48% [15, 17]. In our series, only the episodes with high clinical suspicion of pneumonia and microbiological documentation were considered, accounting for an overall incidence of postoperative pneumonia of 26%. A reduction in the length of stay is also expected with the surgical treatment, but results are conflicting [15, 16, 20, 30]. The most recent randomized controlled study conducted in the United Kingdom with the length of stay as the primary end point, reported a significantly shorter length of stay in surgical patients, as compared with their counterparts (14.5 days vs. 30 days) . The length of stay was longer than in other series [20, 21, 31, 32].
The optimal time for surgery is also important, as delayed surgery may result in pathological bone consolidation. Recent case–control studies [18,19,20] have reported a shorter duration of post-operative mechanical ventilation in patients operated within the first 4–5 days after trauma. In our series, surgery was performed after a median time of 4 days.
The three existing randomized controlled trials do not allow determining whether a surgical approach can benefit in non-intubated and old patients, as in our series. There are several retrospective series with similar population. Farquhar et al.  reported an increased length of stay in operated patients (7.4 ± 6.7 days), as compared with non-operated patients (3.7 ± 6.0 days), but surgery was performed a week after trauma. Wijffels et al.  reported a lower rate of postoperative pneumonia and a shorter hospital length of stay in operated patients, at a price of a higher number of surgery-related complications. Regarding geriatric population, Chen Zhu et al.  reported a decreased ICU and hospital lengths of stay in operated patients, as compared with non-operated patients (3 days vs. 7 days). Ali-Osman et al.  suggested an improved pulmonary function among operated patients despite an increased hospital length of stay.
Altogether, the benefits of surgery seem to exist when performed early after trauma in young patients with respiratory failure despite effective analgesia. In patients without respiratory failure or in older patients, surgical treatment is probably more controversial.
Limitation of the study
The main limitations of our study are related to its retrospective and single center nature, as well as its sample size. The initial medical management of patients was not protocolized, since they were taken care of in a trauma center before being referred to our hospital. Our population was selected for receiving SRFF in an expert center, which makes the results less generalizable. The impact of the surgery on long-term respiratory function and chronic pain was not evaluated.
To summarize, we describe a cohort of 42 thoracic trauma patients with flail chest who received SRFF with titanium plates in an expert thoracic center. The TTSS and SAPSII score without age were independently associated with postoperative complications that occurred in 43% of cases. Conversely, the ISS score was not associated with such complications.
Further trials will help to provide answers about the benefit of the surgery in non-mechanically ventilated patients with isolated chest trauma.