Continuing Education Activity

Muscular hematomas are a common source of extravasated blood from within a muscle group, most commonly occurring in the abdominal waist. Muscular hematomas are typically benign, but spontaneous muscular hematomas have the potential to develop into a life-threatening condition. This activity outlines the evaluation and management of muscular hematomas and examines the role of the interprofessional healthcare team in improving the management of patients who develop muscular hematomas.

Objectives:

• Identify the etiology of muscular hematomas
• Review the appropriate evaluation of muscular hematomas
• Summarize the treatment and management options available for muscular hematomas
• Describe some interprofessional team strategies for improving care coordination and communication to advance the treatment of muscular hematomas and improve outcomes.

Introduction

Muscular hematomas are in simple terms defined by bleeding within a muscle group. These muscular hematomas may be traumatic or spontaneous. Traumatic muscle hematomas, while painful to the patient, are manageable with conservative rest and non-narcotic pain medication. Spontaneous muscle hematomas, in contrast, are mainly located in the abdominal waist area and have the potential to develop into life-threatening conditions.[1]

Etiology

Spontaneous muscular hematomas are classically associated with anticoagulation treatment and typically occur in three anatomic regions:

Anterior Abdominal Musculature

The anterior abdominal wall consists of the rectus abdominis, the external oblique, the internal oblique, and the transverse abdominis. These muscles obtain their vascular supply from the inferior epigastric arteries and the circumflex iliac arteries.

Posterior Abdominal Musculature

The posterior abdominal muscles consist of the iliacus, the psoas, and the erector spinae muscles, each of which receives their vascular supply from the posterior gluteal trunk via the lumbar and iliolumbar arteries.

Muscles of the Buttocks

The muscles of the buttocks are the gluteus maximus, medius, and minimus, as well as the piriformis and the short external rotators. The internal iliac artery supplies this complex of muscles via the superior and inferior gluteal muscles.

Epidemiology

While traumatic muscular hematomas can occur in patients of all demographics, spontaneous muscle hematomas have a significantly increased incidence in the elderly receiving treatment with anticoagulants and occurring in approximately 5% of such patients with an annual mortality rate of 0.65%.[2][3][1]

History and Physical

A history of trauma is common in the presence of traumatic muscular hematomas but may not become clinically relevant for several days, especially when the patient has distracting injuries.

Presentation of spontaneous muscular hematomas are more variable and most commonly present with localized or diffuse pain in the flank or abdomen.  It is essential to inquire about a history of anticoagulant use when there is suspicion of a muscular hematoma, particularly in the geriatric population.

Practitioners should carefully monitor for symptoms of blood loss such as tachycardia, hypotension, and pallor, which can result in anemia and, in more severe cases, organ failure. Note that, generally, the INR will remain within the therapeutic target. Nonetheless, practitioners must be cautious to avoid overprescribing anticoagulants, which can occur in up to 33% of such cases.[4][1]

Evaluation

If a practitioner suspects a spontaneous muscular hematoma, a non-enhanced multidetector computed tomography (MDCT) is the first line indicated imaging test.[5][6] While useful in guiding management, MDCT is limited in its diagnostic capabilities as it cannot localize active extravasation of contrast that would otherwise be visible on a CT-angiogram, which is more capable of indicating both the source of hemorrhage and whether active bleeding is still present. A CT-angiogram has a higher sensitivity than arteriography, especially in the abdomen, with a sensitivity of 80% and specificity of 67%.[7][8]

Treatment / Management

Traumatic hematomas are generally managed conservatively, especially in patients who are not currently receiving treatment with anticoagulants. In these patients, bleeding will usually stop spontaneously.  In contrast, spontaneous muscular hematomas are often the site of active bleeding. A CT-angiogram may be warranted to evaluate better the hematoma and the source and from which vascular structure it originates.

If possible, discontinuation of anticoagulants is the first step in management and may be sufficient to allow for hemostasis to occur and resolution of the muscular hematoma. Surgical evacuation of the hematoma is necessary when there is compression of neurological structures or if the hematoma is causing local ischemia. Of note, the recurrence of these hematomas is common, and careful monitoring is important to identify relapse.[9]

Arterial embolization is sometimes proposed as a treatment option for the management of spontaneous muscular hemorrhages and has the advantage of being less invasive than surgical evacuation while maintaining a clinical success rate of 57 to 69%.[4][10]

Differential Diagnosis

The differential diagnosis of spontaneous muscular hematoma is largely dependent on the location of the bleed. Abdominal wall hematomas must be a consideration in all causes of pain in either the right or left iliac fossa. Furthermore, pain from spinal root compression caused by a hematoma in the lumbar or gluteal regions must merit consideration. Finally, in this region, one should also assess the possibility of a strangulated hernia, torsion of an ovarian cyst, obstruction or perforation of the intestine, abdominal neoplasm, or appendicitis.[11][12][13]

Prognosis

While patients with traumatic muscular hematomas have a very favorable outcome, the mortality of spontaneous muscular hematomas ranges from 4 to 20%. Additionally, there is increased mortality associated with an increased need for blood transfusion, which is in line with the accepted notion that hemodynamic instability is the most significant risk of morbidity and mortality to patients with this condition.

Complications

Myositis ossificans is a reactive process within the muscle secondary to traumatic muscular hematomas characterized by a proliferation of fibroblasts, cartilage, and bone. Most commonly, myositis ossificans occurs within the quadriceps muscles, the brachialis muscle, and the gluteal muscles. This outcome is a self-limiting condition that will typically decrease in size after a year.[14]

Deterrence and Patient Education

Traumatic muscular hematomas will typically resolve spontaneously. However, if a patient does develop a hematoma as a result of a trauma, the patient may benefit from evaluation from a trained medical provider to assess for other injuries. Patients who develop a spontaneous muscular hematoma should be evaluated by a healthcare professional who can carefully weigh the risks and benefits of all treatment options. Anticoagulation therapy should only be stopped by a clinician who knows all medical comorbidities in play, as decisions in management are determined on a case-by-case basis.

Enhancing Healthcare Team Outcomes

Management of muscular hematomas requires the careful collaboration of all members of the healthcare team and a well-rounded interprofessional approach that considers the patient's unique history and needs to achieve the best outcomes. Traumatic muscular hematomas are often the result of a traumatic injury, and therefore should be met with thorough evaluation for traumatic injuries by an appropriate provider. A comprehensive secondary examination can be an effective way to identify less obvious injuries, and radiography is a good initial screening tool. In the setting of trauma, it is important for emergency room staff, nurses, and all consulting physicians to be aware of the potential for unidentified injuries and respond rapidly and appropriately.

Spontaneous muscular hematomas similarly require an interdisciplinary approach to achieve the best outcomes. As spontaneous muscular hematomas frequently present in the elderly with anticoagulation therapy, providers must work in conjunction with the patient's primary care provider to provide appropriate treatment. For example, stopping anticoagulation therapy may be suitable for the management of a patient's spontaneous muscular hematoma but is not reasonable from the perspective of his or her other medical comorbidities. Therefore, all providers involved in the care of this patient must carefully weigh the risks and benefits of any intervention, with consideration given to all medical comorbidities. [Level 5]