Major Vascular and Thoracic Trauma in Nordic Populations

Abstract

Injuries involving major arteries and the thorax are major causes of mortality and morbidity worldwide. Studies on the epidemiology of vascular trauma are scarce and preventive measures are of utmost importance, such as improved roads and safer vehicles. There is a need to better understand factors predictive of mortality in trauma patients who are admitted alive to hospitals, aiming to improve treatment outcomes and lower mortality rates. The aim of this doctoral thesis, which consists of a collection of five scientific articles, is to evaluate outcomes and prognostic factors associated with 30-day and long-term survival in patients with severe injuries to major arteries of the body in two well-defined Nordic patient cohorts, both in Iceland and Bergen. Data regarding patient demographics, mechanism and location of vascular injury and treatment, incidence, overall survival, and injury scores (Injury Severity Score [ISS], New ISS [NISS], and Trauma Score and Injury Severity Score [TRISS]) were recorded. The data were extracted from national and local trauma registries and patient charts. We also calculated Comorbidity Polypharmacy Scores and Comprehensive Complication Indexes to evaluate predictive factors for in-hospital mortality after serious thoracic trauma. In Paper I, adults (age ≥ 18 years) who sustained major vascular injuries in traffic accidents in Iceland in the years 2000–2011 were retrospectively studied. Sixty-two patients (mean age, 44 years; 79% males) sustained 95 major vascular injuries. Before admission, 41 patients died and 21 (34%) reached the hospital alive. The annual incidence for both sexes was 1.69/100 000 inhabitants. A significantly higher proportion of individuals sustained their injuries in rural vs. urban areas (69% vs. 31%, p < 0.01). Patients who died sustained thoracic (76%) or abdominal major vascular trauma (23%). Fatal cases of thoracic aortic injury were largely (77%) attributed to motor vehicle collisions and 74% occurred in rural areas. The average NISS for the 21 admitted patients was 44. Vascular surgery was performed on 18 patients, including three in which endovascular stents were placed. Fifteen of the 21 admitted patients (71%) survived until discharge, and their five-year survival rate was 86%. Paper II included 9 adults who underwent emergency thoracotomy at the accident site, during transport, or just after admission, in Iceland from 2005 to 2010, due to severe chest trauma with a strong suspicion of severe cardiac and/or vascular injury. The median age was 36 years and all were males. Five sustained blunt trauma and four sustained penetrating injuries; six sustained typically isolated thoracic injury and three had polytrauma. The median ISS and NISS were 29 and 50, respectively. Four of the nine patients died and three of those had no sign of life at admission. Five patients survived the injury and procedure and 4 of those made a good recovery. One patient had paraplegia related to spinal injury. Paper III included all 73 patients (average age, 32.6 years; 90.4% males) who were admitted to a hospital in Iceland following penetrating injuries between 2000 and 2015. Most cases were due to assault (96%) and the most frequent locations of injury were the chest (n = 32), abdomen (n = 26), and upper limbs (n = 26). The average ISS was 9, and 14 patients (19%) sustained severe injuries (ISS > 15). Twenty-eight patients required admission to the intensive care unit and 38 patients (51%) needed surgery. Only three patients died within 30 days following the injury (4.1%). In Paper IV, all adults who were admitted to Haukeland University Hospital in Bergen, in the period 2009–2018 with severe chest trauma (with AIS ≥ 3) were studied. There were 514 adults with severe chest trauma (mean age, 51 years; 78% males). The average annual incidence was 13.3/100 000 population over the 10-year study period. Polytrauma patients constituted 61% of patients with an average ISS of 21. Most injuries occurred as a result of traffic accidents (49%) and falls (35%). The multivariate analysis demonstrated that female sex, TRISS with a probability of survival (Ps) of ≤ 50%, having more than nine comorbidities and concurrent medications, and a Comprehensive Complication Index ≥ 30 were significant predictors of in-hospital mortality. The most common severe complication was respiratory failure in 14% of patients and these patients had a 5% 24 h mortality rate and a 30-day mortality rate of 12%. Paper V included 68 adult patients (median age, 44 years; 76% male) who were admitted with vascular injuries to Haukeland University Hospital in Bergen, from 2009–2018. There were 81 vascular injuries: 46 blunt and 22 (32%) penetrating. The annual incidence of major vascular injuries was 1.45/100 000 inhabitants for both sexes. The most frequent locations of injury were the thorax (n = 17), neck (n = 16), and abdominal region (n = 15). The injuries were most often attributed to traffic accidents (n = 31), as well as stab injuries (n = 17) and falls (n = 10). The median ISS was 22 and 50 (74%) patients sustained severe injuries (ISS > 15). Twelve (18%) patients died within 24 h and 6 of those had aortic injuries. These five scientific papers show that serious vascular injuries are an uncommon cause of death in Iceland and Western Norway. The results of treatment and survival are similar to those reported in larger hospitals in North Europe and North America. Most vascular injuries in both Iceland and Bergen were caused by traffic accidents, in contrast to the US and UK where penetrating injuries are much more common causes of vascular injury. The 30-day mortality rate is high after aortic injuries, particularly when they occur in rural areas. Contrary to the impressions of many, the incidence of trauma among patients who were admitted due to stab injuries remained relatively stable in Iceland over the 16-year study period, which is in line with other recent reports. Emergency thoracotomy is a rarely performed procedure in Iceland; however, the survival rate seems higher than reported in publications from Scandinavia. In both Iceland and Norway, a majority of vascular trauma cases were treated via open surgery and endovascular treatment was applied in selected cases. Independent predictors of in-hospital mortality among patients with severe chest injuries were female sex, comorbidities and medications, TRISS with a Ps lower than 50%, as well as the occurrence of in-hospital complications. Previous medical history together with the cause of injury is therefore important information to consider when evaluating trauma patients. Although Iceland and Norway have level 1 trauma centres with low patient volumes and often difficult transport routes, the outcomes of treatment are similar to those reported from high volume centres in Europe and North America, and well-organised trauma centres established in both countries. The findings of these five papers may help to improve the outcomes of seriously injured vascular and thoracic trauma patients and lower both mortality and morbidity. Further improvements in the registration of these injuries are needed in addition to improved training of trauma teams involved in the treatment of patients, to increase knowledge on risk factors related to inferior outcomes which is of vital importance.