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Hematoma and Morel-Lavallée Lesion

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Authors

Shivani Deopujari, MD
Attending Physician

Andrew W Shannon, MD MPH FACEP FAAEM
Associate Professor of Emergency Medicine
Emergency Ultrasound Fellowship Director
University of Florida-Jacksonville College of Medicine.

Summary

  • Early identification of hematoma and Morel-Lavallée (MLL) can be facilitated by ultrasound, improving outcomes
  • Percutaneous drainage can be effective if performed early in the course of disease, but repeated drainage or operative intervention may be required in persistent cases
  • The use of procedural ultrasound can improve lesion localization, provide confidence on adequacy of drainage, and help avoid complications of the procedure when performed by a trained provider.
Video demonstration of a lateral thigh MLL aspiration. The needle is in plane and you can see the hypoechoic fluid collection shrinking.
Video demonstration gastroc tear and hematoma aspiration. You can see the hematoma shrinking as the blood is aspirated.
Ultrasound of a MLL of unknown location.

Introduction

  • Hematoma
    • A hematoma is a localized collection of blood external to the vascular system, most often due to trauma. They can also be iatrogenic or occur spontaneously in patients on anticoagulation or with bleeding diathesis.
    • Although hematomas can occur anywhere, this chapter primarily considers soft tissue lesions such as subdermal and intramuscular hematomas
    • Depending on the depth of the lesion, hematomas may present with pain, swelling, ecchymosis, petechiae and purpura
    • Hematomas can often be diagnosed clinically, with ultrasound or MRI supporting the suspect diagnosis. It may take 48-72 hours before the lesion expands enough to be identifiable on imaging.
    • In general, hematomas are self-limited and self-resolving and can be treated with RICE therapy. In some cases, percutaneous drainage or surgical evacuation may be indicated.
    • The most feared complication is heterotopic ossification, which refers to bony deposition within the hematoma and causes long term morbidity for the patient
  • Morel-Lavallée lesion (MLL)
    • A Morel-Lavallée lesion (MLL) is a rare closed degloving injury, usually resulting from trauma.
    • Shearing forces cause a disruption between the subcutaneous fat and deep fascia, allowing blood, fat, and lymph to accumulate.
    • The resulting fluid collection may develop anywhere from a few hours to a few weeks after the initial injury.
    • The most common site of Morel-Lavallée lesion is over the greater trochanter, although lesions can also occur in the gluteal area, abdomen, lumbar spine, knee, and scapula.[1]Nair AV, Nazar P, Sekhar R, Ramachandran P, Moorthy S. Morel-Lavallée lesion: A closed degloving injury that requires real attention. Indian J Radiol Imaging. 2014;24(3):288-290. … Continue reading
    • This diagnosis is usually delayed due to a combination of slow progression of the lesion and unfamiliarity with the disease. As a result the blood coagulates and is harder to debride.[2]LaTulip S, Rao RR, Sielaff A, Theyyunni N, Burkhardt J. Ultrasound utility in the diagnosis of a morel-Lavallée lesion. Case Rep Emerg Med. 2017;2017:3967587. doi:10.1155/2017/3967587[3]Zhong B, Zhang C, Luo CF. Percutaneous drainage of Morel-Lavallée lesions when the diagnosis is delayed. Can J Surg. 2014;57(5):356-357. doi:10.1503/cjs.034413
    • Treatment can be conservative, with compression wraps and NSAIDs, or invasive, ranging from percutaneous to operative drainage.
    • Percutaneous drainage is well tolerated by patients but may require multiple procedures to effectively drain the lesion. Studies recommend drainage be performed every 1-2 weeks with a compression wrap in place between procedures [4]. In some cases, surgical evacuation may be required.

Anatomy

  • Traumatic shearing forces cause the skin and subcutaneous fat to separate from the deep fascia and musculature. Alternatively, there can be tearing within the soft tissues.
  • The resulting space is then filled with lymph, necrotic fat, and blood.
Morel Lavallee Lesion Illustration
Illustration of the anatomy and mechanism of a Morel Lavallee lesion.[4]Image courtesy of orthobullets.com, “Morel-Lavallee Lesion”

Ultrasound Evaluation

  • Ultrasound can aid in the diagnosis of hematoma and MLL
    • The high frequency linear transducer should be used to evaluate the fluid collection. In patients with a larger body habitus or deeper lesion, the low-frequency, curvilinear transducer may be required
    • Ultrasound allows the physician to identify the location and size of the hematoma or MLL and help exclude other pathology such as abscess, cyst, neoplasm, seroma, etc.
    • Ultrasound may also aid in procedural decision making. For example, lesions smaller than 50 cc may benefit from percutaneous drainage in the ED, whereas larger lesions may benefit from operative treatment as they are more likely to recur.[5]Leach SET, Wotherspoon M, King L. Retrosacral Morel-Lavallée lesion: resolution with ultrasound-guided drainage and sclerotherapy. BJR Case Rep. 2020;6(3):20190120. doi:10.1259/bjrcr.20190120
    • Color Doppler should be used to rule out active blood flow through the fluid collection
  • Hematoma vs MLL
    • Although distinguishing MLL from a hematoma is important, In most cases, this distinction will not be possible in the emergency department (ED) other than by the timeline, mechanism of injury, and location of the injury.
    • If any uncertainty exists, the best way to distinguish between the two is to obtain an MRI with contrast. [6]Wicks JD, Silver TM, Bree RL. Gray scale features of hematomas: an ultrasonic spectrum. AJR Am J Roentgenol. 1978;131(6):977-980. doi:10.2214/ajr.131.6.977
Leg US Large Calf Hematoma
Ultrasound of calf muscles with large, hypoechoic hematoma seen in short axis.
Thigh US Large Intramuscular Hematoma
Ultrasound of quad muscles with a large, hypoechoic hematoma  and a smaller one more superficial seen in short axis. Note the leveling off of blood seen in the larger view.
Video of large medial thigh hematoma in short axis.
Video of large intramuscular calf hematoma in short axis.
  • Hematoma
    • Acute hematomas will appear hyperechoic with internal septations
    • As they age, they will appear anechoic.[7]Wicks JD, Silver TM, Bree RL. Gray scale features of hematomas: an ultrasonic spectrum. AJR Am J Roentgenol. 1978;131(6):977-980. doi:10.2214/ajr.131.6.977
  • MLL
    • Ultrasound evaluation of an MLL will demonstrate a hypoechoic fluid collection located between the subcutaneous tissue and the underlying musculature.
    • Ultrasound may also show septations, internal echoes, or fat globules.
    • Over time, however, sonographic evaluation of MLL lesions may reveal layering of the various fluids, with echogenic foci in an anechoic space.
    • Fat globules, seen as hyperechoic structures located along the outer walls of the lesion, may help distinguish a MLL from a simple hematoma.[8]Nair AV, Nazar P, Sekhar R, Ramachandran P, Moorthy S. Morel-Lavallée lesion: A closed degloving injury that requires real attention. Indian J Radiol Imaging. 2014;24(3):288-290. … Continue reading
Thigh US Morel Lavallee Lesion
Ultrasound of lateral thigh with large MLL. Note the fat globules floating in the hypoechoic fluid. Also note that this lesion is between two tissue planes and not intramuscular like a hematoma.[9]Simpson, Grant, and Brandon Allen. “Morel-Lavallée Lesion.” Journal of Education and Teaching in Emergency Medicine 1.2 (2016).
Thigh US Morel Lavallee Lesion 2
Ultrasound of lateral thigh with anechoic Morel-Lavallée lesion, with a capsule, overlying the left greater trochanter.[10]Robertson, N. L., et al. “Imaging Characteristics of The Morel Lavallee Lesion.” Poster No. P-0100. ESSR: EPOS (2014).
Video of a moderate sized MLL in short axis on the lateral thigh.
Video of a moderate sized MLL in long axis on the lateral thigh.

Procedure

  • Palpation-Guided vs Ultrasound-Guided Approach
    • Percutaneous drainage can be performed using either a palpation-based or ultrasound-guided approach.
    • Ultrasound guidance may be helpful to evaluate for the presence of internal septations and clotted blood, clearly delineate the boundaries of the lesion and ensure adequate aspiration of contents.
Evolution of the aspiration of an MLL
Aspirate of a MLL. Note the concentration of fat cells in the final syringe.
    • Although there are no large studies for comparison, case reports recommend using ultrasound in conjunction with MRI to ensure resolution of the lesion after percutaneous drainage.[11]Leach SET, Wotherspoon M, King L. Retrosacral Morel-Lavallée lesion: resolution with ultrasound-guided drainage and sclerotherapy. BJR Case Rep. 2020;6(3):20190120. doi:10.1259/bjrcr.20190120
  • Challenges to Palpation-Guided Technique
    • Limited by body habitus
    • Multiple needle passes may be required due to unanticipated loculations or tracking of the pocket
    • Multiple attempts are especially traumatic to patients on anticoagulants or antiplatelets
    • Risk of incomplete evacuation of the entire lesion
    • Risk of injury to underlying structures
  • Benefits of Percutaneous Drainage
    • Faster, less expensive than operative repair
    • No general anesthesia, making this approach optimal in high risk surgical patients
    • Shorter recovery time
    • Decreased risk of post-procedural infection
    • Percutaneous drainage can be done in one visit, or over several weeks

Palpation-Guided Technique

  • May be performed with a single provider with a sterile set up
    • An assistant may be helpful to milk the fluid out of the cavity during drainage
  • Position
    • Place the patient in optimal position depending on location of lesion
    • Palpate the area of fluctuance and identify boundaries
    • Inject local anesthetic along your projected approach
  • Open drainage can be achieved with a one or two incision technique
    • Perform a single large incision in the area of maximal fluctuance
    • Perform two small incisions: one to the most superior aspect of the lesion, and one to the most inferior or distal aspect
    • Irrigate the lesion with sterile water
    • Sterile suction can be used to aspirate within the incision. Forceps can be used to break up loculations
    • The incision may be left open to drain, or a loop catheter may be used to prevent reaccumulation of debris within the wound. If available a vacuum dressing may be applied
  • For percutaneous drainage
    • Insert the needle in the area of maximal fluctuance while maintaining negative pressure with the syringe
    • You can again irrigate the lesion with sterile water and use sterile suction to remove fluid via negative pressure
  • Once the fluid has been drained, apply pressure, a sterile dressing, and a compression bandage.
Palpation guided hematomas aspiration 2
Demonstration of a palpation guided aspiration of a lateral thigh hematoma.[12]Image courtesy of Dr Gilmore, “Gumball’s Hematoma Aspiration”
Palpation guided hematomas aspiration
Demonstration of a palpation guided aspiration of a large back hematoma.[13]Brooker, Jack E., Kai Yuen Wong, and Charles M. Malata. “Spontaneous late haematomas at latissimus dorsi flap donor sites: an unusual complication of breast reconstruction.” Journal of … Continue reading

Ultrasound-Guided Technique

  • May be performed with one provider with a sterile setup
    • A two person approach is optimal
    • An assistant may be helpful to milk the fluid out of the cavity during drainage
  • Position
    • Place the patient in optimal position depending on location of lesion
  • Ultrasound setup
    • Identify your optimal approach using ultrasound and delineate boundaries of the lesion
    • Inject local anesthetic along your projected approach
  • Percutaneous drainage
    • The needle should be advanced into the hypoechoic space while maintaining negative pressure on the syringe
    • The needle can be visualized using either a long axis in-plane or short axis out-of-plane approach
    • Aspirate the fluid collection, taking care to aspirate within each separate septation
    • Sterile suction or sterile forceps may be used to aspirate fluid and break up loculations
  • Open or Incisional technique
    • Follow the same steps as described for the palpation-based approach
    • Use ultrasound to estimate the depth needed for the incision
    • Avoid underlying structures, and ensure adequate drainage
  • Once the fluid has been drained, apply pressure, a sterile dressing, and a compression bandage.
Image of a MLL aspiration. The linear transducer is used and the needle is in plane.
Video demonstration of a lateral thigh MLL aspiration. The needle is in plane and you can see the hypoechoic fluid collection shrinking.

Pearls & Pitfalls

  • Early diagnosis is critical. The earlier MLL is diagnosed and treated, the better the prognosis. Certain case studies show nonoperative drainage is only effective if performed within 3-12 days of initial injury
  • Percutaneous drainage in the clinic is tolerated well by patients, however it is important to discuss the possibility that the patient may require additional operative drainage if there is no improvement in the size of the lesion. This is more common in patients who
  • begin with a lesion that is larger than 50 cc
  • Nonoperative drainage may require multiple procedures to effectively remove all fluid within the lesion, with a compression wrap in place between procedures
  • Some case studies recommend injecting sclerosing agents, such as doxycycline and talc, which may be necessary for older or larger MLL
  • If the patient complains of pain during the procedure, have additional local anesthetic available for injection. Patients may also benefit from pre-procedural pain control and anxiolysis
  • An assistant is helpful to manipulate fluid toward the needle or incision, however these procedures can be performed by a solo provider

Special thanks to Dr Audrey Falconi for sharing several videos and images.

References

References[+]