Severe pelvic trauma is a challenging condition. The pelvis can create multifocal hemorrhage that is not easily compressible nor managed by traditional surgical methods such as tying off a blood vessel or removing an organ. Its treatment often requires reapproximation of bony structures, damage control resuscitation, assessment for associated injuries, and triage of investigations, as well as multimodality hemorrhage control (external fixation, preperitoneal packing, angioembolization, REBOA [resuscitative endovascular balloon occlusion of the aorta]) by multidisciplinary trauma specialists (general surgeons, orthopedic surgeons, endovascular surgeons/interventional radiologists). This article explores this complex clinical problem and provides a practical approach to its management.
Key points
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Severe pelvic injury has a high mortality even in modern series.
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Exsanguination from blunt pelvic trauma is a common cause of preventable death.
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Initial treatment generally involves damage control resuscitation and external pelvic wrapping.
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Definitive hemorrhage control may require multiple modalities and multiple disciplines.
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Recognition of associated injuries, particularly the presence of compound fractures, is essential.
Managing patients with severe pelvic fractures is one of the most challenging aspects of trauma care. Pelvic fractures frequently result from high-energy mechanisms, often with associated multisystem injuries, and can lead to catastrophic hemorrhage. There is a high risk for serious morbidity and mortality with these injuries. Trauma registry studies from multiple countries report that unstable pelvic fractures are associated with mortalities ranging from 8% to 32%. However, there has been a trend toward decreased mortality among patients with severe pelvic fractures as trauma care has evolved. Despite advances in trauma care, mortality remains high for the subset of patients presenting with pelvic fractures complicated by hemorrhagic shock. Contemporary studies, using modern best management practices, report mortalities of 32% for these patients.
This article focuses on the current approach to severe pelvic injury, including diagnosis and classification, pelvic binding, angiography and embolization, operative stabilization, and treatment of associated injuries, as well as exploring emerging therapies, including resuscitative endovascular balloon occlusion of the aorta (REBOA) and hybrid operative and angiography suites.
Anatomy and classification for emergency medicine trauma practitioners
The bony anatomy of the pelvis can be conceptualized as a ring formed by the sacrum and right and left innominate bones, specifically the ischium, ilium, and pubis. Viscera of the gastrointestinal and genitourinary system are housed within the bony pelvis. Paired internal iliac arteries and their related tributaries are the predominant arterial supply of the pelvis. The venous system follows a similar path but is arranged in a plexus adherent to the posterior pelvic wall. Pelvic fracture bleeding predominantly arises from the venous plexus or cancellous bone; however, arterial bleeding occurs in a significant number of cases and is associated with life-threatening hemorrhage. Knowledge of pelvic fracture classification is useful in predicting likelihood of severe injury and to aid communication with consultants.
A variety of classification systems have been proposed; the 2 most commonly described in the emergency medicine (EM) literature are the Young-Burgess (YB) and Tile fracture classification systems. The YB system is mechanistically based with fractures classified as lateral compression, anteroposterior compression, vertical shear, or combination injuries with levels of gradation depending on the degree of disruption of the ligamentous and bony stabilizers of the pelvis. The Tile classification system is based on the integrity of the posterior sacroiliac ligaments of the pelvis and associated mechanical instability (Tile A, stable; Tile B, rotationally unstable; Tile C, rotationally and vertically unstable). Further details regarding these classification systems are available in EM and trauma textbooks and review articles. Several studies support the utility of both the YB and Tile systems to predict need for blood transfusion and associated injuries. However, these results have not been consistently replicated across all studies and fracture classification cannot reliability predict mortality. In the subset of patients with persistent shock after initial resuscitation (for the authors, this means an appropriately placed pelvic binder and administration of 2units packed red blood cells and tranexamic acid), the presence of a severe pelvic fracture does predict an increased probability of a pelvic source of hemorrhage and need for arterial embolization. Fracture pattern should be considered as one component of determining the likelihood of an associated vascular or visceral injury but must be interpreted in the context of the patient’s hemodynamic status and associated injuries.
Anatomy and classification for emergency medicine trauma practitioners
The bony anatomy of the pelvis can be conceptualized as a ring formed by the sacrum and right and left innominate bones, specifically the ischium, ilium, and pubis. Viscera of the gastrointestinal and genitourinary system are housed within the bony pelvis. Paired internal iliac arteries and their related tributaries are the predominant arterial supply of the pelvis. The venous system follows a similar path but is arranged in a plexus adherent to the posterior pelvic wall. Pelvic fracture bleeding predominantly arises from the venous plexus or cancellous bone; however, arterial bleeding occurs in a significant number of cases and is associated with life-threatening hemorrhage. Knowledge of pelvic fracture classification is useful in predicting likelihood of severe injury and to aid communication with consultants.
A variety of classification systems have been proposed; the 2 most commonly described in the emergency medicine (EM) literature are the Young-Burgess (YB) and Tile fracture classification systems. The YB system is mechanistically based with fractures classified as lateral compression, anteroposterior compression, vertical shear, or combination injuries with levels of gradation depending on the degree of disruption of the ligamentous and bony stabilizers of the pelvis. The Tile classification system is based on the integrity of the posterior sacroiliac ligaments of the pelvis and associated mechanical instability (Tile A, stable; Tile B, rotationally unstable; Tile C, rotationally and vertically unstable). Further details regarding these classification systems are available in EM and trauma textbooks and review articles. Several studies support the utility of both the YB and Tile systems to predict need for blood transfusion and associated injuries. However, these results have not been consistently replicated across all studies and fracture classification cannot reliability predict mortality. In the subset of patients with persistent shock after initial resuscitation (for the authors, this means an appropriately placed pelvic binder and administration of 2units packed red blood cells and tranexamic acid), the presence of a severe pelvic fracture does predict an increased probability of a pelvic source of hemorrhage and need for arterial embolization. Fracture pattern should be considered as one component of determining the likelihood of an associated vascular or visceral injury but must be interpreted in the context of the patient’s hemodynamic status and associated injuries.
Approach to initial assessment and management of pelvic fractures
The authors’ approach to the assessment and management of the severely injured pelvis is outlined in Fig. 1 . Further details and description are provided later, including exploration of areas of nonconsensus among trauma practitioners.
Initial Resuscitation
Resuscitation of severely injured patients with trauma is covered in depth elsewhere (see Tim Harris and colleagues article, “ The Evolving Science of Trauma Resuscitation ,” in this issue). Specific to patients with severe pelvic fractures is the need to obtain meaningful supradiaphragmatic intravenous (IV) access. The potential for significant injury to the pelvic vasculature renders femoral venous access unreliable, because fluids infused through this location may never reach the right atrium. Two or more large-bore (14–18 gauge) IV catheters placed in the antecubital fossae or an 8-French or 9-French percutaneous introducer sheath placed in the subclavian vein are required to adequately resuscitate a patient with a severely injured pelvis. If initial attempts for peripheral IV catheterization are unsuccessful, then expedient placement of an intraosseous (IO) catheter in the proximal humerus should be sought as a bridge to obtaining adequate IV access. Fluid resuscitation should be consistent with damage control resuscitation principles as espoused in this issue.
The Role of Radiography
Pelvic radiography has traditionally been recommended as an adjunct to the primary survey in all patients with blunt trauma to the torso. The dogma of routine pelvic radiography has recently been challenged by multiple lines of evidence. First, radiography has limited sensitivity for detection of pelvic fractures compared with computed tomography (CT), particularly for sacral and iliac fractures. Second, in hemodynamically stable patients with blunt trauma receiving a CT scan as part of their work-up, the addition of pelvic radiographs does not lead to any significant changes in management. Third, in awake and alert patient who sustain trauma, clinical examination has sufficient sensitivity to exclude significant pelvic fracture. This evidence suggest that routine radiographs can be foregone in selected patients with blunt trauma. Radiographs should still be obtained in patients presenting with altered level of consciousness, abnormal clinical examination, or hemodynamic instability in whom pelvic radiographs can expedite diagnosis and definitive care. Given the lethal risks of missing the diagnosis of a pelvic fracture and the simplicity and minimal risk of obtaining pelvic radiographs, the authors recommend both an examination of pelvic stability and a pelvic radiograph for all stable patients at risk of pelvic injury who will not have a pelvic CT scan performed as part of their trauma diagnostics.
The Role of Focused Assessment with Sonography for Trauma and Diagnostic Peritoneal Lavage
In hemodynamically unstable patients with pelvic fractures, the rapid exclusion of alternative sources of hemorrhage is imperative for making optimal management decisions. Specifically, the trauma provider needs to assess for the presence of significant thoracic and abdominal hemorrhage. The ubiquity of bedside ultrasonography has substantially changed trauma care with the FAST (focused assessment with sonography for trauma) examination frequently used in the work-up of unstable patients with trauma to assess for hemoperitoneum. In general, the presence of free intraperitoneal fluid on FAST and hemodynamic instability is an indication for emergent laparotomy. The presence of free fluid on the FAST examination of a patient with a pelvic fracture has excellent specificity for intra-abdominal lesions requiring surgical intervention. However, this fluid is not always the cause of the patient’s hemodynamic instability. Among a series of patients with pelvic fractures who had positive abdominal FAST examinations, in 19% of cases the free fluid was urine as a result of an intraperitoneal bladder rupture. Interpretation of a negative FAST examination is even more challenging. In the setting of a pelvic fracture, the reported sensitivity of FAST for intraperitoneal fluid ranges from 23% to 80%. This range may be caused by anatomic distortion by pelvic/retroperitoneal hematoma that confounds image interpretation. Although continual improvement in ultrasonography resolution and operator training may attenuate such effects, it must be remembered that the absence of free fluid on a FAST examination in a patient with pelvic fracture does not have sufficient sensitivity to rule out the presence of hemoperitoneum.
Diagnostic peritoneal aspirate (DPA) or diagnostic peritoneal lavage (DPL), first described in 1965, is an alternative method for determining the presence of hemoperitoneum in unstable patients with blunt trauma with pelvic fracture. DPA is the aspiration of fluid from the peritoneal cavity once access to this cavity has been obtained (whether by open cut-down or percutaneous catheter placement). DPA should be performed in an open supraumbilical manner for patients with pelvic fracture. Free aspiration with a syringe of greater than 10 mL of frank blood, gastrointestinal contents, vegetable fibers, or bile in patients with hemodynamic abnormalities mandates laparotomy. In the absence of these findings, DPL is performed by infusing 1000 mL of warmed isotonic crystalloid solution into the peritoneal cavity, which is then mixed by compressing the abdomen and logrolling the patient to each side. The effluent is then drained either by sump action by dropping the IV crystalloid bag onto the floor and allowing the lavage fluid to drain via the infusion catheter, or by aspirating the lavage fluid with a syringe. The lavage fluid is sent for cell count and Gram stain analysis with positive thresholds of greater than 100,000 red blood cells/mm 3 or 500 white blood cells/mm 3 , or presence of bacteria on Gram stain. DPL has excellent sensitivity for hemoperitoneum and is particularly sensitive among hemodynamically unstable patients with trauma. In the investigators’ practice, a positive DPA is viewed as a powerful signal localizing exsanguinating hemorrhage to the abdomen, whereas a nonpositive DPA that proceeds to a DPL requires significant time for the hospital laboratory to analyze the sample to determine the DPL positivity and therefore does not meaningfully inform management of hemodynamically unstable patients with pelvic fracture. In addition, contemporary trauma practitioners have less exposure to DPA/DPL, which limits its applicability. Taking into account the potential difficulties with the pelvic view of the FAST, in the authors’ experience, exsanguinating hemorrhage originating within the peritoneal cavity should have a positive FAST in the upper abdominal views and these are the easiest views to obtain. We reserve DPA for persistently hemodynamically unstable patients with pelvic fractures in whom FAST cannot yield interpretable upper abdominal views (eg, severe bilateral subcutaneous emphysema). The authors think that DPA should be performed by the surgeon who is going to operate on the abdomen if the aspirate is positive, and should not be performed outside of that context.
Pelvic Binding
Temporary stabilization of unstable pelvic fractures with noninvasive external compression (pelvic binding) is recommended as part of routine management. The benefits of this technique are posited through several mechanisms, including prevention of further pelvic motion, reduction of pelvic volume leading to decreased hemorrhage, and lessening patient discomfort. Stabilization can be rapidly achieved through circumferential application of a bed sheet centered at the level of the greater trochanter. Accurate placement is important. Both cadaveric and clinical studies have shown that placement of circumferential binding at locations other than the greater trochanter leads to inadequate reduction. Several commercial devices are also available for pelvic binding. There is insufficient evidence to indicate that any commercial device is superior to binding with a sheet. Certain commercial devices may be advantageous in terms of ease and consistency of application but can impair access to the groin for percutaneous access to the femoral vessels for angiography or REBOA placement, whereas a bedsheet can easily have a defect cut over the vessels to facilitate access while maintaining integrity of the pelvic wrap. Bedsheet wraps can be secured with Kelly clamps to decrease the risk of skin necrosis compared with knots; however, Kelly clamps may cause some CT scan artifact and this can be avoided by using commercially available zip ties ( Fig. 2 ). Cadaveric studies have consistently shown that pelvic binding provides adequate reduction of anterior-posterior compression fractures. Furthermore, pelvic binding has been shown to lead to improved hemodynamics and reduced requirement for blood transfusion.
The utility of pelvic binding in patients with trauma with unstable lateral compression fractures is controversial. There is concern that excessive external compression in this subset of patients can worsen internal rotation deformity. Both clinical and cadaveric studies have confirmed that, when pelvic binders are applied to patients with lateral compression fractures, deformity can worsen. Although no studies have shown a negative clinical impact of this effect, in patients with lateral compression fractures it is prudent to apply pelvic binders with caution, and the recent Western Trauma Association guideline recommends against application of a pelvic binder in this setting. In these situations, the binder should be applied, if at all, with the aim of reducing further fracture displacement rather than correcting any rotational deformity. Trauma providers should be aware of case reports of skin breakdown with pelvic binding and avoid applying excessive traction. A postbinding pelvic radiograph can be obtained to ensure reapproximation of the pelvic ring. As shown in Fig. 1 , the authors place a pelvic binder immediately on diagnosing a mechanically unstable fracture on physical examination or in hemodynamically unstable patients with significant pelvic fractures on radiograph.
Resuscitative Endovascular Balloon Occlusion of the Aorta
REBOA is an endovascular or internal cross-clamp of the aorta. The creation of REBOA as a viable clinical tool in the twenty-first century is the result of the merger of endovascular technology with the trauma surgeon’s knowledge and expertise in the principles of damage control resuscitation. The emergence of REBOA is in many ways in response to the difficulty of controlling bleeding from a severely injured pelvis and the lack of universal efficacy of other hemorrhage control measures. First described in 1954 by Col. Hughes during the Korean War, the technique has undergone several variations in the trauma setting and benefitted from advances made in endovascular aortic aneurysm repair. The informal use of the intra-aortic balloon pump, most conventionally used for cardiogenic shock, to control gastrointestinal hemorrhage has been reported, as has several other such case reports. Involvement of the United States and its allies in armed conflicts in Iraq and Afghanistan in the first decade of the twenty-first century generated significant research relating to the battlefield deaths and injuries sustained by military personnel. Out of this research, the need for a technique to treat noncompressible torso hemorrhage was identified and in 2014 the Joint Theater Trauma System clinical practice guideline for the use of REBOA for hemorrhagic shock was released. This practice guideline included the use of REBOA in the algorithm for traumatic arrest and in the management of profound shock. In 2013, Brenner and colleagues published their clinical series using REBOA in 6 patients. Following this clinical breakthrough, the American Association for the Surgery of Trauma (AAST) multi-institutional study entitled Aortic Occlusion for Resuscitation in Trauma and Acute Care Surgery (AORTA) was initiated to compare resuscitative thoracotomy with REBOA in participating US trauma centers. Results published from this registry have shown the clinical efficacy of this resuscitative tool in the treatment of profound hemorrhagic shock. Note that the use of aortic balloon occlusion has also been reported in France, the United Kingdom, Australia, and most notably in Japan. The reported experiences in Japan of more than 450 cases of REBOA use have not shown improved mortality and have reported significant complications, such as limb loss. However, the clinical context of REBOA deployment and use seem to differ significantly from North American deployment and experience, and thus cannot be directly compared.
As a clinical tool in the treatment of severe hemorrhage from pelvic fractures, the REBOA balloon is typically deployed in zone III of the aorta, or just above the aortic bifurcation (see Megan Brenner and Christopher Hicks article, “ Major Abdominal Trauma: Critical Decisions and New Frontiers in Management ,” in this issue). First-generation technology involves obtaining arterial access to the common femoral artery and placement of a 12-French sheath, then placement of an endovascular guidewire within the descending aorta, and then positioning and inflation of a Coda balloon (Cook Medical Inc, Bloomington IN). Although ideally performed under real-time fluoroscopy, the often dire circumstances of its placement as well as the results of the AORTA registry support its placement using radiographs and sometimes only anatomic landmarks. Successful placement using ultrasonography has also been reported.
Second-generation technology, in the form of the ER-REBOA Catheter (Prytime Medical Devices, Boerne TX), has now become available with approval by the US Food and Drug Administration in October 2015 and achievement of the CE (Conformité Européene) mark of approval (European Union) in December 2016. This device is a single stiff balloon occlusion catheter with integrated arterial pressure monitoring that is placed through a 7-French arterial access sheath, thereby removing the requirement for common femoral artery placement and mandatory arterial vascular repair as was the case with the use of 12-French sheath equipment. Data regarding the performance of this specific catheter are not yet available but it is in use at major trauma centers across the United States at the time of writing.
Where available, REBOA is currently recommend to be placed in aorta zone III in the setting of a patient with pelvic trauma who continues to be hemodynamically unstable despite pelvic wrapping and appropriate resuscitation. Successful placement of REBOA in this setting is a temporizing maneuver and involves creating total lower-body ischemia. Minimizing the duration of balloon inflation is therefore critical, and such a patient should be taken emergently to the operating room (OR)or angiographic suite as dictated by their other injuries and institutional capabilities. The authors consider REBOA deployment for patients who are persistently hemodynamically unstable after pelvic binding and initial resuscitation (see Fig. 1 ). REBOA deployment may be considered in the setting of traumatic cardiac arrest as an alternative to resuscitative thoracotomy in certain settings (see Chris Evans and colleagues article, “ Reanimating the Traumatic Cardiac Arrest Patient: A Practical Approach Informed by Best Evidence ,” in this issue). Most recent available data from US trauma centers on REBOA use indicate the necessity for arterial cut-down in 50%, radiographic guidance being used in 50%, mean procedure times of approximately 6 minutes, and no reports of limb ischemia or amputation. However, data regarding the impact of second-generation REBOA technology on these parameters are not yet available.
The ultimate role for this evolving technique remains to be determined, as does the type of practitioner who may safely use it. However, its future may include use not only at high-level trauma centers but conceivably at rural and remote hospitals without surgical capabilities or meaningful blood product stocks that are forced to manage patients exsanguinating from a lower-body source.
Hemorrhage control
Following initial trauma bay resuscitation, patients with pelvic fractures and ongoing hemodynamic instability require further intervention to achieve hemorrhage control. Potential options include (1) external pelvic fixation, (2) extraperitoneal packing, and (3) angiographic embolization. REBOA, as described earlier, may be placed in the emergency department (ED) as a temporizing bridge to obtaining definitive hemorrhage control. These treatment options and their combined application and sequencing are discussed in further detail later.
External Pelvic Fixation
Compared with pelvic binding, external percutaneous fixation provides more definitive control of a mechanically unstable pelvis and reduces pelvic volume to tamponade venous bleeding. There are 2 general approaches for external fixation described in the literature. For rotationally unstable anterior-posterior compression and lateral compression fractures an anterior external fixation approach is preferred. In the case of vertically unstable pelvic fractures a C-clamp device is used to stabilize posterior pelvic elements ( Fig. 3 ). Case series of patients managed with percutaneous external fixation suggest that this technique is effective in reducing hemorrhage and may have a mortality benefit. Application of external pelvic fixation devices has been described in both the trauma bay and the OR settings. In the modern era, given the efficacy and easy of applicability of external pelvic binding techniques, percutaneous fixation is best reserved for the OR. Provider experience with this technique is crucial because reported complications include neurovascular injury caused by screw malposition, fixation failure, and infection.
