Background
Trauma is one of the leading causes of death in western countries, and the most frequent one in people below forty [
1]. Whenever the body’s integrity is compromised by contusion, concussion or fracture, surgical trauma care is necessary for rapid damage control and specific individualized treatment. This remains, a major challenge for clinicians due to varying patterns of injuries and occasional major traumas, requiring urgent, yet highly specialized therapy [
2,
3]. Fast, conclusive and complete injury assessment by examination of head and neck, thorax, abdomen, pelvis and the extremities is further supported by computed tomography (CT) and CT-angiography (CTA) [
4,
5].
Head and thoracic injuries are found in approximately 50% of all trauma patients and extremity or pelvic fractures in roughly 30% [
6]. Additional vascular damage, especially of arteries or venous plexus is acutely life threatening and further reduces time for decision-making and treatment [
7]. Vascular damage in combination with fractures is associated with higher mortality and inferior outcome, especially due to rapid and voluminous blood loss into pelvic or femoral soft tissue compartments. Correct diagnosis may be difficult due to low body temperature and masking effects of other injuries [
8‐
10]. Doppler ultrasound and CTA increase the detection rate, yet incorrect diagnosis remains frequent thus requiring re-examination after initial stabilization [
11,
12]. Depending on type and extent of trauma, presentations may be acute bleeding, hemodynamic instability, pulsating tumors, massive hematoma or ischemic and pulseless extremities [
13]. Additionally, vasospasm or complete vascular disruption both may mimic ischemia [
14].
Despite recognized difficulties in detecting vascular injury in extremity trauma as well as an increased mortality rate in combination with pelvic trauma, limited data about the immediate clinical implications of vascular damage associated with fractures is available. We therefore analyzed thoroughly demography, initial laboratory results, treatment and outcome of extremity and pelvic fracture-associated vascular injuries in a trauma cohort of 64 patients versus a comparable cohort of patients with isolated osseous damage in a nine-year retrospective single-center study was carried out.
Aim of the study:
The aim of this retrospective cohort study was to recognize patterns of injury where vascular damage and fracture occur and also identification of surrogate parameters which may suspect a vascular involvement in major trauma patients. In addition, the influences of concomitant vascular damage to patient’s management and outcome were analyzed.
Methods
Facility
A university hospital and level-one trauma center, embedded in the regional trauma network (Traumanetzwerk Nordbayern-Würzburg) was analyzed. A multidisciplinary team provides twenty-four-seven trauma care; following standard operating procedures according to guidelines of the German National Society for Trauma Surgery (DGU) are implemented. Ultrasound, X-ray and multi-slice computed tomography (CT) are available on site in the trauma room. A board-certified vascular surgeon and an interventional radiologist are part of the trauma team.
Patient identification.
A retrospective analysis of all admissions to the surgical trauma room from December 2005 until December 2013 identified 3689 cases, including primary trauma admissions and secondary transfers from other centers.
The initial analysis included trauma mechanism and pattern of injuries, specifically identifying all vascular damages. Additional examination included fractures, immediate vascular, visceral, urologic or pediatric surgery or invasive vascular diagnostics and interventions. Every case with vascular involvement and extremity or pelvic fracture was then analyzed for age, sex, blunt or penetrating trauma, hospital stay, intensive care unit (ICU) stay, number of operations, method of treatment, amputation, death, trauma scores (Glasgow coma scale, GCS; injury severity index, ISS; Revised Injury Severity Classification Score, RISC I), preclinical fluid management and initial laboratory results. Data were available for 100% of patients, except for preclinical fluid management (36.7 and 49.3% for vascular injury group and fracture only group, respectively).
This cohort (vascular injury group) was then subdivided in regard to localization of the fracture, upper/lower extremity or pelvis, and the corresponding vascular damage. Patients with vascular involvement of the head and neck (N = 36), i.e. carotid artery dissection, were excluded in this study.
Control group
In order to compare outcome and laboratory results, a control group consisting of 60 major trauma patients with limb/pelvic fractures only and no additional vascular damage, based on CTA, clinical assessment and clinical course, was selected. Inclusion criteria were surgical trauma room admission and fractures without further vascular, visceral, thoracic, spinal or cranial damage.
Statistics
Group comparisons of count data were performed with χ2 tests when the smallest value in the contingency table was 5 or more, otherwise Fisher’s exact test was performed. Normally distributed measurement values (Shapiro-Wilk p ≥ 0.05) were examined with the Welch two sample t-test, in cases where the normality assumption did not hold (Shapiro-Wilk p < 0.05) the Wilcoxon rank sum test was applied. Dependencies between measurement values were examined with linear regression. Endpoint (survival) analyses were performed with Cox regression. P-values < 0.05 were considered significant.
Discussion
Fracture-associated vascular injury of the limbs and especially the pelvis may have severe consequence for the patient. Accurate detection, early treatment and supportive therapy determine the outcome [
15].
Mechanisms of vascular trauma include blunt trauma (external force or through fracture fragments), sharp trauma or strain which might lead to disruption or intima damage leading to ischemia (Fig.
3) [
16,
17]. Presentation is thus hemorrhage or ischemia, a phenomenon best described for supracondylar humeral fracture or knee trauma [
18‐
20]. The initial clinical symptoms, especially hemodynamic instability, were not available retrospectively in our cohort. Nevertheless, the established algorithm of local CT-angiography in case of suspected severe fracture of the pelvis and the extremities provided good results, since all patients with vascular injury were identified immediately and no late amputations due to ischemia occurred [
5,
12,
21].
In 3–9% of fractures a concomitant vascular damage is reported varying due to regional and socioeconomic factors [
10,
22‐
24]. In this single-center cohort we identified an accompanying vascular damage in 7% of the fractures. Required treatments were very heterogeneous, for the fracture-associated vascular injury as well as vascular incidents in general (Fig.
1). Unfortunately, most publications are case reports or case series focusing on a specific entity or treatment, thus not catering for the need for more general data analysis [
25]. No conclusive pattern of injury for consecutive vascular damage could be identified in our cohort, in fact, vascular damage has to be expected regardless of the fracture localization, the impact of trauma or any trauma scores (Table
2).
This data displays a similar incidence of vascular injury in upper/lower extremity and pelvic fractures. Nevertheless, outcomes such as higher immediate mortality in pelvic fractures and significant amputation rates for the lower extremity are area-specific (Fig.
1 and Table
2). The management is considerably influenced by the degree of tissue damage and occasional primary subtotal amputation. Of 15 pelvic fractures, 4 were classified stable while the rest were type B/C fractures (Pennal and Tile classification) possibly yielding additional rupture of the venous plexus. Patients with fractures and vascular injuries also show a longer hospital stay and higher number of operative procedures (Table
2). Elevated immediate mortality in the fracture only group was due to the higher rate of multiple fractures, suggestive of more severely trauma (Table
2 and Additional file
2: Table S2). The additional severity of vascular damage to multi-injured patients is currently not reflected by any trauma score (Table
2).
This study demonstrates the effect of additional vascular damage on the admission laboratory data (Table
1 and Additional file
2:Table S2 and Additional file
3: Table S3). The presented results show similar trends in overall, as well as entitiy-specific analysis (Additional file
2: Table S2). Low hemoglobin, and altered coagulation were, however, associated with an increased need of fluid in the preclinical course. Thus some dilution effect has to be taken into consideration However, the available data in retrospective analysis was not available in all patients, and results have to be interpreted carefully. Nevertheless, substantial fluid administration and low initial hemoglobin, i.e. by rapid blood gas analysis, may raise the attention to direct diagnostics to identifying vascular damage. Trauma-induced coagulation defect is a severe co-morbidity, strongly associated with an increased mortality [
26]. Early therapy might also include platelet-directed treatments [
27,
28].
Ever since the late stages of World War II, where ligation of arteries and veins was the treatment of choice, surgical and technical abilities have evolved towards a diversified armamentarium, significantly increasing limb salvage and survival rates, nowadays enabling individualized care [
29,
30]. Especially rapid endovascular repair for bleeding control has evolved as primary option for certain clinical entities of vascular injury, like embolization in pelvic bleeding, stentgraft implantation in aortic transection or thoracic outlet vessel breach [
22,
25,
31,
32]. However, mangled extremities remain a domain of open vascular repair (Fig.
1). Open fracture, eventual contamination and massive tissue loss require autologous reconstruction [
9,
33,
34].
Acknowledgments
We thank S. Duell for administrative help and C. Wagner for help with patient identification in SAP. We especially thank all the nursing and medical staff that makes working in the emergency room possible every day and night.