Diagnostic and therapeutic roles of bronchoscopy and video-assisted thoracoscopy in the management of thoracic trauma

Indications and patient section

In order to achieve the benefits of minimally invasive techniques in the chest following trauma, patient selection is key. The indications are both diagnostic and therapeutic and include the evaluation of a structural injury (the diaphragm, the pericardium, lung parenchyma, the thoracic duct, etc.) or the drainage of a pleural collection and repair of any structural damage. Aside from the usual bleeding disorders, the main contraindications of VATS include an unstable patient or a patient with underlying lungs and cardiac pathologies that preclude the use of single lung ventilation. Table 1 lists the current indications and contraindications for the use of VATS.

Surgical approach

The operation is performed under general endotracheal intubation with a dual lumen endotracheal tube. The position of the tube is confirmed bronchoscopically. The patient is positioned in the lateral decubitus position and flexed at the hip to open the rib spaces. The initial 10-mm port is placed at the site of the existing chest tube or in the midaxillary line in the fifth intercostal space. This port is used to introduce a camera with a 30- or 45-degree scope into the pleural cavity and to aid in the placement of additional 5-mm working ports. A maximum of two working ports are usually used, along with a 5-mm 30-degree scope, to allow complete inspection of the lung and pleural spaces. Insufflation is not required; however, it can be helpful when full lung collapse is not achieved. At the end of the procedure, chest tubes are placed under direct observation through existing port sites. The lung is then inflated under direct vision. Patient-controlled analgesia along with local intercostal nerve block is used for optimal postoperative pain management.

Morbidity and complication management

The reported complication rates for thoracoscopy are less than 10% and the missed injury rates are less than 1%. The perioperative complications include intrathoracic bleed (parietal, intercostal, or parenchymal), recurrent pneumothorax and hemothorax. Other complications include intercostal neuritis and iatrogenic lung laceration. Conversion to open thoracotomy is reported to be less than 8% and is usually due to inadequate thoracoscopic visibility, dense pleural adhesions with failure to deflate the lung, or uncontrollable bleed. This underscores the importance of the timing of the procedures, within 3 to 7 days—early enough to avoid pleural adhesions and fibrosis and late enough to assure adequate hemostasis. Persistent air leak in the postoperative period is attributed to underlying lung pathology such as emphysema or apical bleb disease. Late complications are rare and include the development of pneumonia, pleural edema, and empyema. Airway complications from malpositioned dual lumen endotracheal tubes and the development of tension pneumothorax during one lung ventilation have also been reported.

Diaphragmatic injuries

The incidence of blunt diaphragmatic injuries remains as low as 0.8% and as high as 7%, and blunt trauma accounts for 10% to 30% of traumatic diaphragmatic ruptures. Following penetrating trauma, the incidence of diaphragmatic injuries has been reported to be as low as 15% and as high as 67%. Diaphragmatic injuries are particularly difficult to diagnose with the use of radiographic imaging such as chest x-ray or conventional CT and can be missed in up to 30% of patients. The use of high-resolution axial, coronal, and sagittal reformatted images in multidetector row CT in most urban trauma centers has significantly improved the accuracy of diaphragm injury. However, additional diagnostic evaluation is still required to definitively exclude diaphragm injury in patients with equivocal CT findings defined as thickening of the diaphragm, artifact secondary to ballistic fragments, injury in the proximity of the diaphragm, and wound tracts outlined by air, blood, bullet, or bone fragment extending up to the diaphragm. In several studies the sensitivity of CT for blunt and penetrating diaphragm injury varied between 80% and 90% depending on the study and mechanism. In a recent 10-year study (2008–2018) by Yanik et al, the missed radiologic injury rate of diaphragm injuries detected via VATS in hemodynamically stable patient after penetrating thoracic trauma, was noted to be 18%. Despite the recent advancement in CT technology, no large prospective studies are available to further clarify the role of CT in detection of diaphragmatic injuries in thoracoabdominal penetrating injuries. To date VATS or abdominal laparoscopy remains the most definitive diagnostic tool for diaphragmatic injuries when compared to other nonoperative modalities. Thoracoscopy is particularly useful for evaluation of right-sided diaphragmatic injuries and posterior wounds from the posterior axillary line to the spine (i.e., when laparoscopy may not be feasible). It is also useful in stable patients with previous laparotomies, and expected history of adhesive disease, where an abdominal approach may not be optimal.

The therapeutic role of VATS in the treatment of diaphragmatic injuries is well documented and supported by the Western Trauma Association critical decisions algorithms and by the practice management guideline of the Eastern Association for the Surgery of Trauma. In a report of 24 patients who underwent VATS for thoracic injuries, 9 of 10 patients were successfully diagnosed with diaphragmatic injuries. VATS was used for repair of the diaphragm in four patients. Martinez et al evaluated 52 patients with penetrating thoracoabdominal trauma. VATS was used to diagnose 35 patients with diaphragmatic injuries. All 35 diaphragmatic injuries were successfully repaired thoracoscopically. In patients in whom other abdominal injuries are suspected, a laparoscopic or open surgical approach is preferable depending on the surgical expertise available. A combined thoracic and abdominal cavitary endoscopy can also be useful. Figure 1 shows the thoracoscopic evaluation of a right diaphragm injury from an impaled object in the chest of a patient evaluated in our trauma center. This was followed by the thoracoscopic repair of the diaphragm after the laparoscopic confirmation of a nonbleeding liver laceration and no other associated abdominal injuries. In all cases where a diaphragm injury is found, an exploratory laparoscopy or laparotomy should be strongly considered to rule out associated intraabdominal injuries.

Retained thoracic collection

Multiple studies have demonstrated the effectiveness of VATS for management of retained hemothorax. In a study by the American Association for the Surgery of Trauma, 328 patients with posttraumatic retained hemothorax from 20 centers in the United States, Canada, and South America were prospectively evaluated over a 2-year period. VATS was the most common initial management approach after diagnosis of retained hemothorax, with patients managed by VATS requiring no further therapy in 70% of cases. The evacuation of a retained hemothorax remains one of the main indications for VATS. Inadequate evacuation of blood from the pleural space and prolonged thoracostomy tube drainage puts the patient at risk for developing empyema and fibrothorax with prolonged hospital stays and increasing costs. The incidence of a retained hemothorax and empyema post–tube thoracostomy placement ranges from 4% to 20% and from 4% to 10%, respectively. In the 2011 American Association for the Surgery of Trauma plenary paper, empyema was identified slightly higher than previous studies at 26.8% (88 of 328) of study patients with a prolonged increase of intensive care unit (ICU) by an average of 4.6 days and hospital length of stay by an average of 7 days. A prospective randomized study of 39 patients from Parkland Memorial Hospital with thoracic trauma and retained hemothoraces demonstrated that early evacuation with VATS compared to conventional therapy of a secondary chest tube placement leads to a significantly shorter duration of tube drainage (2.5 days), shorter hospital stay (2.7 days), and reduced hospital costs ($6,000). These advantages of VATS were attributed to rapid and complete evacuation of the pleural space, optimal video-assisted positioning of the thoracostomy tubes, identification, and treatment of the sources of the bleeding and of other associated intrathoracic injuries.

It is important to note that these advantages rest on the early use (day 4–7 post injury) of VATS for the evacuation of the hemothorax. No level I data are available in the literature regarding when VATS should be performed for a persistent posttraumatic hemothorax. However, level II evidence does exist as noted in the 2011 Eastern Association for the Surgery of Trauma practice management guidelines for VATS to be performed within the first 3 to 7 days of hospitalization to decrease the risk of infection and need for thoracotomy. Multiple early studies from the University of Louisville noted 75% success rate for thoracoscopic evacuation of retained posttraumatic hemothorax when performed within 5 days. Failure of VATS correlated with time interval from injury to operation and with the type of fluid collection (hemothorax vs. empyema). The advantage of early intervention correlated with significant decrease in conversions to open thoracotomy (8% vs. 29.4%, p < .05) and shorter lengths of hospital stay (11 ± 6 days vs. 16 ± 8 days, p < 0.05). VATS performed after 5 days of admission were more likely to show a diagnosis of empyema (29.4 % vs. 10%, p < .0001). Finally, in a recent systemic review and meta-analysis of six cohort studies with 476 total participants, the success rate of VATS performed within the first 3 days of admission was significantly higher than that for VATS performed on day 7 or later. Moreover, patients who underwent early VATS (within 72 hours) were discharged 21 days earlier than the patients who underwent late VATS after day 6 (95% confidence interval −23.6 to −19, p < .001).

Acute and persistent hemorrhage

Up to 30% of patients sustaining thoracic injuries require urgent exploration, which is typically performed via thoracotomy. Unstable patients with suspected thoracic bleed require open thoracotomy. In appropriately selected, hemodynamically stable patients with evidence of active hemorrhage, VATS can be successfully performed within the first 24 hours following thoracic trauma with minimal morbidity, obviating the need for thoracotomy. In a study by Goodman et al, urgent VATS (within 24 hours) was performed on 23 patients, with 6 (26%) for suspected diaphragmatic or esophageal injuries, 16 (70%) for bleeding, and 1 (4%) for open/persistent pneumothorax. Six (26%) patients underwent pulmonary wedge resections for lung lacerations, and 11 (48%) patients underwent evacuation of a hemothorax. No conversion to thoracotomy or reoperation was required.

VATS is also useful for patients with persistent but slow hemorrhage, with no hemodynamic instability. Smith et al performed VATS on five hemodynamically stable patients for persistent hemorrhage from intercostal vessels. In three patients, the bleeding was successfully controlled with diathermy. Other techniques including endoclips or argon beam coagulators for hemorrhage control can be used. Intracorporal stitch placement around the rib was used successfully in our center for control of a persistent intercostal bleed not amenable to endoclip placement. The success rate for the thoracoscopic control of a nonhemodynamically compromising hemorrhage is around 80% with a thoracotomy conversion rate of 15% to 20%.

Persistent pneumothorax

Posttraumatic residual pneumothorax after thoracostomy tube removal is a potential risk and not an uncommon occurrence. The reported ranges vary greatly extending from 4% to 50%, with the incidence increasing with severity of thoracic injury and thinner chest walls. The incidence of persistent air leak and lung reexpansion 72 hours after thoracostomy tube placement ranges from 4% to 23%. VATS has been shown to be safe and effective in the treatment of persistent pneumothorax with decreased number of chest tube days, hospital length of stay, and cost. In a study by Smith et al, 8 (10%) of 83 patients were undergoing VATS for persistent air leak with failed lung reexpansion for greater than 72 hours. All were successfully treated with thoracoscopic surgery without conversion thoracotomy; however, the source of the air leak was identified in only 50% of patients. Despite the low rate of localization, all were successfully managed with VATS pleurodesis. Endo-GIA staplers are now routinely employed to staple off the affected lung parenchyma. The use of a topical synthetic nonreactive surgical sealant (Coseal; Baxter, Freemont, California) for the creation of an elastic watertight seal has also been reported. Prior to committing a patient to VATS, it is important to aggressively evaluate the cause of the air leak and rule out a malfunctioning or a malpositioned chest tube, the presence of a foreign body, or a deeply penetrating rib fragment. The patient should be evaluated thoroughly with chest tomography and bronchoscopy to evaluate the tracheobronchial tree, the distal parenchyma, and the pleural cavity.