James V. O'Connor

Operative repair or endovascular stent graft in blunt traumatic thoracic aortic injuries: results of an American Association for the Surgery of Trauma Multicenter Study.

INTRODUCTION The purpose of this American Association for the Surgery of Trauma multicenter study is to assess the early efficacy and safety of endovascular stent grafts (SGs) in traumatic thoracic aortic injuries and compare outcomes with the standard operative repair (OR). PATIENTS Prospective, multicenter study. Data for the following were collected: age, blood pressure, and Glasgow Coma Scale (GCS) at admission, type of aortic injury, injury severity score, abbreviate injury scale (AIS), transfusions, survival, ventilator days, complications, and intensive care unit and hospital days. The outcomes between the two groups (open repair or SG) were compared, adjusting for presence of critical extrathoracic trauma (head, abdomen, or extremity AIS >3), GCS score </=8, systolic blood pressure <90 mm Hg, and age >55 years. Separate multivariable analysis was performed, one for patients without and one for patients with associated critical extrathoracic injuries (head, abdomen, or extremity AIS >3), to compare the outcomes of the two therapeutic modalities adjusting for hypotension, GCS score </=8, and age >55 years. RESULTS One hundred ninety-three patients met the criteria for inclusion. Overall, 125 patients (64.9%) were selected for SG and 68 (35.2%) for OR. SG was selected in 71.6% of the 74 patients with major extrathoracic injuries and in 60.0% of the 115 patients with no major extrathoracic injuries. SG patients were significantly older than OR patients. Overall, 25 patients in the SG group (20.0%) developed 32 device-related complications. There were 18 endoleaks (14.4%), 6 of which needed open repair. Procedure-related paraplegia developed in 2.9% in the OR and 0.8% in the SG groups (p = 0.28). Multivariable analysis adjusting for severe extrathoracic injuries, hypotension, GCS, and age, showed that the SG group had a significantly lower mortality (adjusted odds ratio: 8.42; 95% CI: [2.76-25.69]; adjusted p value <0.001), and fewer blood transfusions (adjusted mean difference: 4.98; 95% CI: [0.14-9.82]; adjusted p value = 0.046) than the OR group. Among the 115 patients without major extrathoracic injuries, higher mortality and higher transfusion requirements were also found in the OR group (adjusted odds ratio for mortality: 13.08; 95% CI [2.53-67.53], adjusted p value = 0.002 and adjusted mean difference in transfusion units: 4.45; 95% CI [1.39-7.51]; adjusted p value = 0.004). Among the 74 patients with major extrathoracic injuries, significantly higher mortality and pneumonia rate were found in the OR group (adjusted p values 0.04 and 0.03, respectively). Multivariate analysis showed that centers with high volume of endovascular procedures had significantly fewer systemic complications (adjusted p value 0.001), fewer local complications (adjusted p value p = 0.033), and shorter hospital lengths of stay (adjusted p value 0.005) than low-volume centers. CONCLUSIONS Most surgeons select SG for traumatic thoracic aortic ruptures, irrespective of associated injuries, injury severity, and age. SG is associated with significantly lower mortality and fewer blood transfusions, but there is a considerable risk of serious device-related complications. There is a major and urgent need for improvement of the available endovascular devices.

Diagnosis and treatment of blunt thoracic aortic injuries: changing perspectives.

BACKGROUND The diagnosis and management of blunt thoracic aortic injuries has undergone many significant changes over the last decade. The present study compares clinical practices and results between an earlier prospective multicenter study by the American Association for the Surgery of Trauma completed in 1997 (AAST1) and a new similar study completed in 2007 (AAST2). METHODS The AAST1 study included 274 patients from 50 participating centers over a period of 30 months. The AAST2 study included 193 patients from 18 centers, over a period of 26 months. The comparisons between the two studies included the method of definitive diagnosis of the aortic injury [computed tomography (CT) scan, aortography, transesophageal echocardiogram (TEE) or magnetic resonance imaging], the method of definitive aortic repair (open repair vs. endovascular repair, clamp and sew vs. bypass techniques), the time from injury to procedure (early vs. delayed repair), and outcomes (survival, procedure-related paraplegia, other complications). RESULTS There was a major shift of the method of definitive diagnosis of the aortic injury, from aortography in the AAST1 to CT scan in AAST2, and a nearly complete elimination of aortography and TEE in the AAST2 study. In the AAST2 study the diagnosis was made by CT scan in 93.3%, aortography in 8.3%, and TEE in 1.0% of patients when compared with 34.8%, 87.0%, and 11.9%, respectively, in the AAST1 study (p < 0.001). The mean time from injury to aortic repair increased from 16.5 hours in the AAST1 study to 54.6 hours in the AAST2 study (p < 0.001). In the AAST1 study, all patients were managed with open repair, whereas in the AAST2 study only 35.2% were managed with open repair and the remaining 64.8% were managed with endovascular stent-grafts. In the patients managed with open repair, the use of bypass techniques increased from 64.7% to 83.8%. The overall mortality, excluding patients in extremis, decreased significantly from 22.0% to 13.0% (p = 0.02). Also, the incidence of procedure-related paraplegia in patients with planned operation, decreased from 8.7% to 1.6% (p = 0.001). However, the incidence of early graft-related complications increased from 0.5% in the AAST1 to 18.4% in the AAST2 study. CONCLUSIONS Comparison between the two AAST studies in 1997 and 2007 showed a major shift in the diagnosis of the aortic injury, with the widespread use of CT scan and the almost complete elimination of aortography and TEE. The concept of delayed definitive repair has gained wide acceptance. Endovascular repair has replaced open repair to a great extent. These changes have resulted in a major reduction of mortality and procedure-related paraplegia but also a significant increase of early graft-related complications.

Blunt Traumatic Thoracic Aortic Injuries: Early or Delayed Repair—results of an American Association for the Surgery of Trauma Prospective Study

BACKGROUND The traditional approach to stable blunt thoracic aortic injuries (TAI) is immediate repair, with delayed repair reserved for patients with major associated injuries. In recent years, there has been a trend toward delayed repair, even in low-risk patients. This study evaluates the current practices in the surgical community regarding the timing of aortic repair and its effects on outcomes. METHODS This was a prospective, observational multicenter study sponsored by the American Association for the Surgery of Trauma. The study included patients with blunt TAI scheduled for aortic repair by open or endovascular procedure. Patients in extremis and those managed without aortic repair were excluded. The data collection included demographics, initial clinical presentation, Injury Severity Scores, type and site of aortic injury, type of aortic repair (open or endovascular repair), and time from injury to aortic repair. The study patients were divided into an early repair (< or = 24 hours) and delayed repair groups (> 24 hours). The outcome variables included survival, ventilator days, intensive care unit (ICU) and hospital lengths of stay, blood transfusions, and complications. The outcomes in the two groups were compared with multivariate analysis after adjusting for age, Glasgow Coma Scale, hypotension, major associated injuries, and type of aortic repair. A second multivariate analysis compared outcomes between early and delayed repair, in patients with and patients without major associated injuries. RESULTS There were 178 patients with TAI eligible for inclusion and analysis, 109 (61.2%) of which underwent early repair and 69 (38.8%) delayed repair. The two groups had similar epidemiologic, injury severity, and type of repair characteristics. The adjusted mortality was significantly higher in the early repair group (adjusted OR [95% CI] 7.78 [1.69-35.70], adjusted p value = 0.008). The adjusted complication rate was similar in the two groups. However, delayed repair was associated with significantly longer ICU and hospital lengths of stay. Analysis of the 108 patients without major associated injuries, adjusting for age, Glasgow Coma Scale, hypotension, and type of aortic repair, showed that in early repair there was a trend toward higher mortality rate (adjusted OR 9.08 [0.88-93.78], adjusted p value = 0.064) but a significantly lower complication rate (adjusted OR 0.4 [0.18-0.96], adjusted p value 0.040) and shorter ICU stay (adjusted p value = 0.021) than the delayed repair group. A similar analysis of the 68 patients with major associated injuries, showed a strong trend toward higher mortality in the early repair group (adjusted OR 9.39 [0.93-95.18], adjusted p value = 0.058). The complication rate was similar in both groups (adjusted p value = 0.239). CONCLUSIONS Delayed repair of stable blunt TAI is associated with improved survival, irrespective of the presence or not of major associated injuries. However, delayed repair is associated with a longer length of ICU stay and in the group of patients with no major associated injuries a significantly higher complication rate.

Management of post-traumatic retained hemothorax: a prospective, observational, multicenter AAST study.

Background: The natural history and optimal management of retained hemothorax (RH) after chest tube placement is unknown. The intent of our study was to determine practice patterns used and identify independent predictors of the need for thoracotomy. Methods: An American Association for the Surgery of Trauma multicenter prospective observational trial was conducted, enrolling patients with placement of chest tube within 24 hours of trauma admission and RH on subsequent computed tomography of the chest. Demographics, interventions, and outcomes were analyzed. Logistic regression analysis was used to identify the independent predictors of successful intervention for each of the management choices chosen and complications. Results: RH was identified in 328 patients from 20 centers. Video-assisted thoracoscopy (VATS) was the most commonly used initial procedure in 33.5%, but 26.5% required two and 5.4% required three procedures to clear RH or subsequent empyema. Thoracotomy was ultimately required in 20.4%. The strongest independent predictor of successful observation was estimated volume of RH ⩽300 cc (odds ratio [OR], 3.7 [2.0–7.0]; p < 0.001). Independent predictors of successful VATS as definitive treatment were absence of an associated diaphragm injury (OR, 4.7 [1.6–13.7]; p = 0.005), use of periprocedural antibiotics for thoracostomy placement (OR, 3.3 [1.2–9.0]; p = 0.023), and volume of RH ⩽900 cc (OR, 3.9 [1.4–13.2]; p = 0.03). No relationship between timing of VATS and success rate was identified. Independent predictors of the need for thoracotomy included diaphragm injury (OR, 4.9 [2.4–9.9]; p < 0.001), RH >900 cc (OR, 3.2 [1.4–7.5]; p = 0.007), and failure to give periprocedural antibiotics for initial chest tube placement (OR 2.3 [1.2–4.6]; p = 0.015). The overall empyema and pneumonia rates for RH patients were 26.8% and 19.5%, respectively. Conclusion: RH in trauma is associated with high rates of empyema and pneumonia. VATS can be performed with high success rates, although optimal timing is unknown. Approximately, 25% of patients require at least two procedures to effectively clear RH or subsequent pleural space infections and 20.4% require thoracotomy. Level of Evidence: II, prospective comparative study.

Development of posttraumatic empyema in patients with retained hemothorax: Results of a prospective, observational AAST study

BACKGROUND The natural history of retained hemothorax (RH), in particular factors contributing to the subsequent development of empyema, is not well known. The intent of our study was to establish the modern incidence of empyema among patients with trauma and RH and identify the independent predictors for development of this complication. METHODS An American Association for the Surgery of Trauma multicenter prospective observational trial was conducted, enrolling patients with placement of a thoracostomy tube within 24 hours of trauma admission, and subsequent development of RH was confirmed on computed tomography of the chest. Demographics, interventions, and outcomes were analyzed. Logistic regression analysis was used to identify the independent predictors for the development of empyema. RESULTS Among 328 patients with posttraumatic RH from the 20 participating centers, overall incidence of empyema was 26.8% (n = 88). On regression analysis, the presence of rib fractures (adjusted odds ratio [OR], 2.3; 95% confidence interval [CI], 1.3–4.1; p = 0.006), Injury Severity Score of 25 or higher (adjusted OR, 2.4; 95% CI, 1.3–4.4; p = 0.005), and the need for any additional therapeutic intervention (adjusted OR, 28.8; 95% CI, 6.6–125.5; p < 0.001) were found to be independent predictors for the development of empyema for patients with posttraumatic RH. Patients with empyema also had a significantly longer adjusted intensive care unit stay (adjusted mean difference, 4.1; 95% CI, 1.3–6.9; p = 0.008) and hospital stay (adjusted mean difference, −7.9; 95% CI, −12.7 to −3.2; p = 0.01). CONCLUSION Among patients with trauma and posttraumatic RH, the incidence of empyema was 26.8%. Independent predictors of empyema development after posttraumatic RH included the presence of rib fractures, Injury Severity Score of 25 or higher, and the need for additional interventions to evacuate retained blood from the thorax. Our findings highlight the need to minimize the risk associated with subsequent thoracic procedures among patients with critical illness and RH, through selection of the most optimal procedure for initial evacuation. LEVEL OF EVIDENCE Prognostic study, level III.

Assessing Behind Armor Blunt Trauma (BABT) Under NIJ Standard-0101.04 Conditions Using Human Torso Models

BACKGROUND Although soft armor vests serve to prevent penetrating wounds and dissipate impact energy, the potential of nonpenetrating injury to the thorax, termed behind armor blunt trauma, does exist. Currently, the ballistic resistance of personal body armor is determined by impacting a soft armor vest over a clay backing and measuring the resulting clay deformation as specified in National Institute of Justice (NIJ) Standard-0101.04. This research effort evaluated the efficacy of a physical Human Surrogate Torso Model (HSTM) as a device for determining thoracic response when exposed to impact conditions specified in the NIJ Standard. METHODS The HSTM was subjected to a series of ballistic impacts over the sternum and stomach. The pressure waves propagating through the torso were measured with sensors installed in the organs. A previously developed Human Torso Finite Element Model (HTFEM) was used to analyze the amount of tissue displacement during impact and compared with the amount of clay deformation predicted by a validated finite element model. All experiments and simulations were conducted at NIJ Standard test conditions. RESULTS When normalized by the response at the lowest threat level (Level I), the clay deformations for the higher levels are relatively constant and range from 2.3 to 2.7 times that of the base threat level. However, the pressures in the HSTM increase with each test level and range from three to seven times greater than Level I depending on the organ. CONCLUSIONS The results demonstrate the abilities of the HSTM to discriminate between threat levels, impact conditions, and impact locations. The HTFEM and HSTM are capable of realizing pressure and displacement differences because of the level of protection, surrounding tissue, and proximity to the impact point. The results of this research provide insight into the transfer of energy and pressure wave propagation during ballistic impacts using a physical surrogate and computational model of the human torso.

Daily multidisciplinary discharge rounds in a trauma center: a little time, well spent.

BACKGROUND Patient flow in a trauma center can be improved by multidisciplinary discharge rounds (MDR), but the content and logistics of MDR discussions have not been well quantified for purposes of improvement and adoption. We characterized the discussion content and time spent during MDRs and measured success rates in implementing communicated plans. METHODS Bedside MDRs in seven patient care units were observed during consecutive working days in a major academic trauma center. PATIENT Discussions were timed and their content coded. Coding reliability was assessed with kappa statistics. Implementations of communicated plans were assessed during sequential working days. RESULTS MDRs over 23 days comprising 1,769 patient-discussions were observed. MDRs lasted a median of 34 minutes for a median of 78 patients. Kappa statistics for the discussions were 0.63 to 0.96. Each patient-discussion lasted a median of 13 seconds (range, 2 seconds-233 seconds), and 96% lasted less than a minute. Clinical topics were presented in 71.5%, new complications in 12%, discharge plans in 67%, surgical plans in 19%, and care advancement in 8% of them. Discussions >30 seconds duration were likely to contain exploration of care advancement, systems related, and clinical topics (p < 0.05). Advancement of care exploration correlated moderately with census of the trauma center (r = 0.53, p = 0.01). Ninety-four percent of the communicated plans were implemented with most delays caused by systems factors (82%). CONCLUSIONS The short duration and goal-focused communication may have made MDRs sustainable. Given the benefits of successful implementation of communicated plans and previously demonstrated improved patient outcomes, time for MDRs is well spent.

Occupant and Crash Characteristics for Case Occupants With Cervical Spine Injuries Sustained in Motor Vehicle Collisions

BACKGROUND Motor vehicle collisions (MVCs) are the leading cause of spine and spinal cord injuries in the United States. Traumatic cervical spine injuries (CSIs) result in significant morbidity and mortality. This study was designed to evaluate both the epidemiologic and biomechanical risk factors associated with CSI in MVCs by using a population-based database and to describe occupant and crashes characteristics for a subset of severe crashes in which a CSI was sustained as represented by the Crash Injury Research Engineering Network (CIREN) database. METHODS Prospectively collected CIREN data from the eight centers were used to identify all case occupants between 1996 and November 2009. Case occupants older than 14 years and case vehicles of the four most common vehicle types were included. The National Automotive Sampling Systems Crashworthiness Data System, a probability sample of all police-reported MVCs in the United States, was queried using the same inclusion criteria between 1997 and 2008. Cervical spinal cord and spinal column injuries were identified using Abbreviated Injury Scale (AIS) score codes. Data were abstracted on all case occupants, biomechanical crash characteristics, and injuries sustained. Univariate analysis was performed using a χ analysis. Logistic regression was used to identify significant risk factors in a multivariate analysis to control for confounding associations. RESULTS CSIs were identified in 11.5% of CIREN case occupants. Case occupants aged 65 years or older and those occupants involved in rollover crashes were more likely to sustain a CSI. In univariate analysis of the subset of severe crashes represented by CIREN, the use of airbag and seat belt together (reference) were more protective than seat belt alone (odds ratio [OR]=1.73, 95% confidence interval [CI]=1.32-2.27) or the use of neither restraint system (OR=1.45, 95% CI=1.02-2.07). The most frequent injury sources in CIREN crashes were roof and its components (24.8%) and noncontact sources (15.5%). In multivariate analysis, age, rollover impact, and airbag-only restraint systems were associated with an increased odds of CSI. Using the population-based National Automotive Sampling Systems Crashworthiness Data System data, 0.35% of occupants sustained a CSI. In univariate analysis, older age was noted to be a significant risk factor for CSI. Airbag-only restraint systems and both rollover and lateral crashes were also identified as risk factors for CSI. In addition, increasing delta v was highly associated with CSIs. In multivariate analysis, similar risk factors were noted. Of all the restraint systems, seat belt use without airbag deployment was found to be the most protective restraint system (OR=0.29, 95% CI=0.16-0.50), whereas airbag-only restraint was associated with the highest risk of CSI (OR=3.54, 95% CI=2.29-5.46). CONCLUSIONS Despite advances in automotive safety, CSIs sustained in MVC continue to occur too often. Older case occupants are at an increased risk of CSI. Rollover crashes and severe crashes led to a much higher risk of CSI than other types and severity of MVCs. Seat belt use is very effective in preventing CSI, whereas airbag deployment may increase the risk of occupants sustaining a CSI. More protection for older occupants is needed and protection in both rollover and lateral crashes should remain a focus of the automotive industry. The design of airbag restraint systems should be evaluated so that they are not causative of serious injury. In addition, engineers should continue to focus on improving automotive design to minimize the risk of spinal injury to occupants in high severity crashes.

Damage-control thoracic surgery: Management and outcomes.

BACKGROUND Damage-control surgery is successfully used for severe abdominal trauma. Although the damage-control surgery principles are applicable to thoracic trauma, there is a dearth of data on damage-control thoracic surgery. METHODS This is an institutional review board–approved, retrospective trauma registry study, from January 2002 to December 2012, for thoracic injuries requiring emergency thoracotomy or sternotomy, with temporary closure. Demographics, physiologic and laboratory data, operative procedures, and outcomes were abstracted. Data are presented as mean and SD; Student’s t test was used with p < 0.05 conferring statistically significance. RESULTS Forty-four patients were identified, with a median age of 34 years and 86% males. Mean (SD) Injury Severity Score (ISS) was 33.2 (14.7), with 93% having a chest Abbreviated Injury Scale (AIS) score of 3 or greater, 61% having a chest AIS score of 4 or greater, and 32% having a chest AIS score of 5 or greater. Of the patients, 48% had gunshot wounds and 21% had stab wounds. Admission temperature, pH, base deficit, and international normalized ratio were 36°C (1°C), 7.07 (0.13), 11.1 (6.5), and 1.7, respectively. Incisions included anterolateral thoracotomy in 69% and sternotomy in 25%; 73% required pulmonary resection, 20% required cardiorraphy, and 9% had major vascular injuries; multiple procedures were common. Mean intraoperative transfusion was 13 U of packed red blood cells. Forty-two patients (95%) had thoracic packing with vacuum-assisted closure. The thorax was closed when physiology normalized, on a mean (SD) of 3 (1) days. When comparing physiologic parameters at initial operation and chest closure, temperature was 34.4°C (1.3°C) versus 37.4°C (0.8°C), pH was 7.13 (0.14) versus 7.38 (0.6), and international normalized ratio was 1.8 (0.9) versus 1.2 (0.3), respectively, all statistically significantly (p < 0.001). Complications included sepsis (36%), renal failure requiring continuous renal replacement therapy (30%), adult respiratory distress syndrome (25%), and empyema (23%). Six required salvage extracorporeal membrane oxygenation with one survivor. Mortality was 23%. Predictors included higher ISS, renal failure, continuous renal replacement therapy, and extracorporeal membrane oxygenation. All survivors were neurologically intact and dialysis free. CONCLUSION Patients with severe chest trauma and marked physiologic derangement can benefit from damage-control thoracic surgery. Thoracic packing and temporary vacuum closure avoids thoracic compartment syndrome. Timing of thoracic closure is based on physiology. While complications were common, mortality is acceptable in this group of severely injured, metabolically depleted, challenging patients. LEVEL OF EVIDENCE Therapeutic study, level V.

Penetrating cardiac injury

It is understood that penetrating cardiac trauma is a highly lethal injury and those surviving to hospital have an overall mortality approaching 80%. Reported mortality figures vary widely and are extremely dependent on mechanism of wounding, cardiac chambers involved and possibly the presence of cardiac tamponade. Despite significant advances in prehospital care, operative techniques, and intensive care management, the mortality has not changed over several decades. This article will review the anatomic regions of concern for a cardiac injury, clinical presentation, and physical findings. The need for an expeditious evaluation and modalities available including, plain radiographs, sub-xiphoid window, and echocardiography will be considered. Options for surgical exposure, technical details of repairing cardiac injuries, and special circumstances such as injury adjacent to a coronary artery and intra-cardiac shunts are discussed in detail. Outcome data and future directions in managing this challenging injury are also examined.