CT-lung volume estimates in trauma patients undergoing stabilizing surgery for flail chest

Perioperative considerations for patients undergoing surgical stabilization of rib fractures: A narrative review

Surgical stabilization of rib fractures (SSRF) has become an increasingly common management strategy for traumatic rib fractures. Although historically managed with supportive care, patients with multiple rib fractures and flail chest increasingly undergo SSRF, and so the anesthesiologist must be well-versed in the perioperative management and pain control for these patients, as controlling pain in this population is associated with decreased length of stay and improved outcomes. There are multiple modalities that can be used for both pain control and as part of the anesthetic plan in patients undergoing SSRF. This narrative review provides a comprehensive summary of anesthetic considerations for surgical rib fracture patients, covering the preoperative, intraoperative, and postoperative periods. We describe an approach to the assessment of high-risk patients, analgesic and anesthetic techniques including emerging techniques within locoregional anesthesia, ventilation strategies, and potential complications. This review also identifies areas where additional research is needed to ensure optimal anesthetic management for patients undergoing SSRF.

Is it Necessary to Stabilize Every Fracture in Patients with Serial Rib Fractures in Blunt Force Trauma?

Introduction

Management of traumatic rib fractures is subject of controversial discussions. Rib fractures are common, especially after traffic accidents and falls. There is no consensus on whether and how many rib fractures need reconstruction. Not every rib fracture needs to be stabilized, but conservative treatment by internal splinting and analgesia is not effective for all patients. Deformities of the chest wall with reduced thoracic volume and restrictive ventilation disorders must be avoided. Intraoperative assessment of fractures and chest stability plays a central role.

Material and methods

From 07/2016 to 07/2021, a total of 121 chest wall stabilizations were performed (m:f = 2:1, age 65 ± 14.5 a). Indications for surgery were the following criteria: (1) palpatory instability of the chest wall, (2) dislocated fracture endings, (3) concomitant injuries, (4) uncontrollable pain symptoms. In all patients, a computed tomography scan of the thorax was performed before the osteosynthetic treatment to assess dislocation of the fracture endings and possible concomitant injuries of intrathoracic organs.

Results

Video-assisted thoracoscopy was performed in all patients. Hemothorax and concomitant injuries of the lung, diaphragm and mediastinum could be assessed. This was followed by an intraoperative assessment of the rib fractures, in particular penetration of fracture endings and resulting instability and deformity. Relevant fractures could be identified and subsequent incisions for rib osteosynthesis precisely defined. 6.3 (±2.7) rib fractures were detected, but 2.4 (±1.2) ribs treated osteosynthetically. Bilateral rib fractures were present in 26 patients (21.5%). Post-operative bleeding occurred in seven patients (5.8%), a breakage of the osteosynthetic material in two patients (1.7%).

Discussion

Intraoperative assessment of relevant fractures and dislocation is the decisive criterium for osteosynthesis. Thoracoscopy is mandatory for this purpose - also to identify accompanying injuries. Not every fracture has to be approached osteosynthetically. Even with serial rib fractures or multiple fractures in a single rib, the thoracic contour can be restored by stabilizing only relevant fractures. Intraoperative palpation can adequately assess the stability and thus the result of the osteosynthesis. Even after surgical treatment of thoracic trauma, adequate analgesia and respiratory therapy are important to the healing process.

Three-dimensional volume-rendered computed tomography application for follow-up fracture healing and volume measurements pre-surgical rib fixation and post-surgical rib fixation

BACKGROUND

Surgical rib fixation (SRF) is being used increasingly in trauma centers for stabilization of chest wall injuries, in line with new and evolving surgical techniques. Our institution has developed a pathway for the management of chest wall injuries and SRF, which includes a follow-up low-volume, noncontrast computed tomography (CT) scan at 12 months.

METHODS

This study was a single-center retrospective study conducted on 25 consecutive patients who underwent SRF between February 2019 and February 2020. All CT measurements were done by a CT radiographer under the supervision of a board-certified radiologist and included the use of three-dimensional volume-rendered images.

RESULTS

There were no patients with SRF who experienced hardware failure at 12 months in either flail or nonflail groups. For fractured ribs treated with SRF, complete or partial union occurred in 75 of 76 ribs plated (98.7%). The median ratio for improvement in lung volumes was 1.71 for flail SRF and 1.69 for nonflail SRF in our study.

CONCLUSION

Three-dimensional volume-rendered CT at 12 months post-SRF showed good alignment (no hardware failure) and fracture healing of fixed ribs in both flail and nonflail groups. Lung volumes also improved pre-SRF and post-SRF for both flail and nonflail patients. More studies are needed to define how the pattern of rib fracture healing of fixed and nonfixed ribs affects lung volumes.

LEVEL OF EVIDENCE

Therapeutic, Level V.

The Chinese consensus for surgical treatment of traumatic rib fractures 2021 (C-STTRF 2021)

Rib fracture is the most common injury in chest trauma. Most of patients with rib fractures were treated conservatively, but up to 50% of patients, especially those with combined injury such as flail chest, presented chronic pain or chest wall deformities, and more than 30% had long-term disabilities, unable to retain a full-time job. In the past two decades, surgery for rib fractures has achieving good outcomes. However, in clinic, there are still some problems including inconsistency in surgical indications and quality control in medical services. Before the year of 2018, there were 3 guidelines on the management of regional traumatic rib fractures were published at home and abroad, focusing on the guidance of the overall treatment decisions and plans; another clinical guideline about the surgical treatment of rib fractures lacks recent related progress in surgical treatment of rib fractures. The Chinese Society of Traumatology, Chinese Medical Association, and the Chinese College of Trauma Surgeons, Chinese Medical Doctor Association organized experts from cardiothoracic surgery, trauma surgery, acute care surgery, orthopedics and other disciplines to participate together, following the principle of evidence-based medicine and in line with the scientific nature and practicality, formulated the Chinese consensus for surgical treatment of traumatic rib fractures (STTRF 2021). This expert consensus put forward some clear, applicable, and graded recommendations from seven aspects: preoperative imaging evaluation, surgical indications, timing of surgery, surgical methods, rib fracture sites for surgical fixation, internal fixation method and material selection, treatment of combined injuries in rib fractures, in order to provide guidance and reference for surgical treatment of traumatic rib fractures.

A new quantitative assessment method for predicting pneumonia caused by chest wall injury

BACKGROUND

The severity of rib fractures has been previously evaluated by combining categorical data, but these methods have only low predictive capability for respiratory complications and mortality. This study aimed to establish a more accurate method for predicting the development of pneumonia, a frequent complication in chest injuries, using anatomical relationships.

METHODS

We analyzed three-dimensional reconstructed images of 644 consecutive trauma patients who underwent whole-body computed tomography (CT) in our institution within a 36-month study period from April 2017. The anatomical relationship between the right and left thoracic volumes of non-rib fracture patients was used to estimate thoracic volume changes on the injured side in unilateral rib fracture patients. The predictive capability of changes in thoracic volume for the development of pneumonia was evaluated according to the area under the receiver operating characteristic curve and compared with that of previous chest wall severity evaluation methods.

RESULTS

Of the 644 patients, 133 and 478 patients had unilateral rib fractures and non-rib fractures, respectively. The amount of change in thoracic volume due to unilateral rib fractures was significantly greater in pneumonia patients (400 mL vs. 160 mL, p < 0.01). The area under the receiver operating characteristic curve for the development of pneumonia was 0.83, which tended to be higher than that of the previous severity scoring methods.

CONCLUSION

The amount of change in chest volume, which can be estimated using CT images, has better predictive capability for pneumonia than previous severity assessment methods based on categorical data. The amount of change in chest volume measured using whole-body CT can be used to rapidly determine the optimal treatment for severe chest wall injuries.

LEVEL OF EVIDENCE

Prognostic study, level IV.

A model for evaluating the biomechanics of rib fracture fixation

INTRODUCTION

High rates of morbidity and mortality following flail chest rib fractures are well publicized. Standard of care has been supportive mechanical ventilation, but serious complications have been reported. Internal rib fixation has shown improvements in pulmonary function, clinical outcomes, and decreased mortality. The goal of this study was to provide a model defining the biomechanical benefits of internal rib fixation.

METHODS

One human cadaver was prepared with an actuator providing anteroposterior forces to the thorax and rib motion sensors to define interfragmentary motion. Cadaveric model was validated using a prior study which defined costovertebral motion to create a protocol using similar technology and procedure. Ribs 4-6 were fixed with motion sensors anteriorly, laterally and posteriorly. Motion was recorded with ribs intact before osteotomizing each rib anteriorly and laterally. Flail chest motion was record with fractures subsequently plated and analyzed. Motion was recorded in the sagittal, coronal and transverse axes.

FINDINGS

Compared to the intact rib model, the flail chest model demonstrated an 11.3 times increase in sagittal plane motion, which was reduced to 2.1 times the intact model with rib plating. Coronal and sagittal plane models also saw increases of 9.7 and 5.1 times, respectively, with regards to flail chest motion. Both were reduced to 1.2 times the intact model after rib plating.

INTERPRETATION

This study allows quantification of altered ribcage biomechanics after flail chest injuries and suggests rib plating is useful in restoring biomechanics as well as contributing to improving pulmonary function and clinical outcomes.

When will pulmonary function recover after rib fracture?

Rib fracture is almost recovered with conservative management including oral medication. Pain is easily controlled with medication, but physiologic function is not readily evaluated. This study is aimed to investigate the factors influencing to recovery of pulmonary function test (PFT) and changes according to times after rib fracture. From August 2015 to January 2018, medical records of patients with rib fracture were reviewed retrospectively. Factors may influencing to recovery of PFT (age, chronic obstructive pulmonary disease, numbers of fractures, intercostal nerve block) were evaluated, and serial (initial, 1 month, 2 months) changes of parameters PFT (forced vital capacity [FVC], forced expiratory volume in 1 sec [FEV₁], total lung capacity [TLC], vital capacity [VC]) for 2 months were observed. Total patients were 60, and PFT was completed 38 and 27 patients after 1 month and 2 months respectively. Mean age was 55.1 years (20–84 years) and mean numbers of fracture were 3.98 (1–11). Intercostal nerve block and rib fixation were performed in 32 cases and 2 cases respectively. Age, numbers of fracture and intercostal nerve block were not significant factors to changes of PFT. But chronic obstructive pulmonary disease was significant factor to recovery of FEV₁ in 1 month. PFT was improved in FVC, FEV₁ through 2 months, and improved in TLC, VC in 1 month. This study showed the evidence and prognosis of physiologic recovery after rib fracture. And we could tell about physiologic recovery to rib fracture patients with this study.