Management of recurrent post-traumatic seroma of thigh (Morel-Lavallée lesion) by percutaneous aspiration and sclerotherapy using tetracyclines (PAST)

Abstract

Morel-Lavallée lesion is a chronic, recurrent collection of serous fluid in the soft tissues and usually occurs following injury. The most common sites are thigh, hip and pelvic region. This presents as a local or diffuse swelling and may cause discomfort to the patient besides being a potential site for bacterial contamination. So, early diagnosis and timely management is crucial for an early and successful outcome. The investigation modality of choice for diagnosis of these lesions is MRI. Definitive management ranges from percutaneous aspiration with or without sclerotherapy to open debridement and irrigation. Although recurrences are common with conservative management, it can be minimised with judicious use of sclerotherapy.

Background

In 1853, French physician Maurice Morel-Lavallée described a post-traumatic condition in which a soft tissue seroma developed due to separation of subcutaneous fatty layer from the underlying deep fascia.^{1 2} These commonly occur at the greater trochanter, anterolateral thigh, flanks, buttocks and scapula.³ They may present acutely or may have a delayed presentation after months or years.² This may cause discomfort or pressure symptoms and has the potential risk of getting infected. Ultrasound and MRI aid in early and accurate diagnosis.⁴ Timely diagnosis and management helps to prevent complications such as contour deformity and skin necrosis. The management may vary from draining the fluid by percutaneous aspiration, percutaneous drainage with suction tubes, compression bandages, injection of sclerosants and surgical management if conservative approach fails.^{5 6}

Case presentation

A 22-year-old female patient presented to our hospital with chief complaints of a vague, slightly painful swelling over the posterolateral aspect of right proximal thigh. She had a history of fall from motorcycle 1 year ago following which she developed a gradually progressive swelling. She had also sustained pelvic bone fracture, which was managed conservatively. She did not have any associated illnesses.

On clinical examination, a diffuse and irregular soft, non-tender swelling of size 8×15 cm was noticed over posterolateral aspect of right proximal thigh. She had marked contour asymmetry as compared with the opposite thigh.

Investigations

Ultrasonography (USG) was performed which was suggestive of subcutaneous seroma as shown in figure 1.

Figure 1.

Ultrasonography showing seroma.

MRI of the right thigh revealed a walled off area of fluid collection in the deep subcutaneous plane over the upper and lateral aspect of right thigh measuring 5.7×1.2×15 cm with minimal fibrosis at inferior margin suggestive of a post-traumatic seroma (Morel-Lavallée lesion) as shown in figure 2.

Figure 2.

MRI scan showing seroma.

Fine needle aspiration of fluid showed dark straw-coloured hazy fluid (figure 3) and peripheral smear revealed red blood cells and a few non-malignant lymphocytes.

Figure 3.

Seroma aspiration.

Culture and sensitivity was done two times and revealed no growth for any organism.

Differential diagnosis

MRI is a superior investigation and helps in differentiating it from other similar soft tissue conditions such as fat necrosis, myositis or any tumour with greater accuracy.

Treatment

First session—USG-guided percutaneous aspiration was done using 18-gauge needle and 40 mL straw-coloured serous fluid was aspirated. The patient was advised to wear compression stocking post aspiration.

Second session—Patient came with recurrence of the swelling 3 weeks later. Repeat USG-guided percutaneous aspiration of 30 cm³ of straw-coloured serous fluid was done.

Despite two sessions of aspiration, the patient presented with recurrence of the swelling again as shown in figure 4 and a decision to perform ultrasound-guided percutaneous aspiration and injection sclerotherapy was taken. The sclerosant chosen for intralesional sclerotherapy was 100 mg doxycycline diluted to 10 mL solution with distilled water.

Figure 4.

Seroma before first session.

Informed consent was taken prior to the procedure.

First session—25 mL serous dark straw-coloured fluid was first aspirated using 18-gauge needle under USG guidance, 10 mL of sclerosant (doxycycline) was then slowly injected into the cavity without local anaesthesia. Compression crepe bandage was applied immediately after the procedure and the patient was advised to continue wearing compression stocking throughout the day.

During follow-up visit after 3 weeks, the size of lesion had significantly reduced.

Second session—The size of seroma had decreased considerably and only 6 mL of sclerosant could be injected into the cavity (figure 5).

Figure 5.

Cavity on second session.

During the follow-up visit after another 3 months (figure 6), clinical examination revealed almost complete remission of the swelling and USG showed complete resolution of seroma.

Figure 6.

Final Ultrasonography after 3 months

Outcome and follow-up

The patient was advised to follow-up after 3 months. There was no swelling on clinical examination and USG revealed complete resolution of seroma. She was advised to wear compression stockings for the next 6 months. Now, at the end of 1 year, there is no swelling and discomfort.

Discussion

Morel-Lavallée lesion is a post-traumatic degloving injury creating a potential space.² This leads to accumulation of blood and lymph from the shearing of tissues. Chronic inflammatory reaction is induced which generates a fibrous capsule around the collection in the long term. Morel-Lavallée lesions may present as a painless swelling which might increase with time and cause discomfort to the patient and occasionally get infected. Early diagnosis is crucial to prevent complications such as contour deformity or skin necrosis. Female patients with body mass index greater than 25 have a greater predisposition to this condition.³

Commonly involved sites are the greater trochanter, anterolateral thigh, flanks, buttocks and scapula. The greater trochanter is the most commonly involved region due to the superficial location of femoral cortex, mobility of the soft tissues and the strength of the underlying tensor fascia lata.³

Postoperative seromas are a common complication following breast and abdominal wall surgeries, postliposuction and postbariatric body contouring. This occurs due to shearing of lymphatic and blood vessels, creation of dead space and also due to increased use of electrocautery.⁷ While seromas contain largely acellular fluid, Morel-Lavallée lesions are filled with serosanguinous fluid and an inflammatory cellular debris.⁸

Despite differing in their aetiology, postoperative seromas and Morel- Lavallee Lesion (MLL) share a common pathological evolution as well as clinical presentation. Hence, evaluation and treatment of both these conditions tend to fall along the same lines.^{8 9}

MLL is diagnosed clinically and aided by radiological investigations to support and confirm the diagnosis. USG is usually the initial investigation to detect seroma and to know its location and the plane, which is usually superficial to the muscular place.¹⁰ MRI is a superior investigation and helps in differentiating it from other similar soft tissue conditions such as fat necrosis, myositis or any tumour with greater accuracy.^{11 12}

Acute and smaller lesions can be managed with percutaneous aspiration and compression garment till the lesion resolves. Once capsule has formed, conservative treatment is not much effective, and requires some kind of intervention. It can be managed by repetitive percutaneous aspiration with or without sclerodesis, vacuum assisted closure (VAC) therapy. Surgical excision of capsule or capsulectomy is usually the last option.¹³

Sclerotherapy generates an inflammatory reaction leading to tissue adhesion. This obliterates the dead space. Sclerotherapy has been traditionally used since a long time to manage malignant pleural effusions, varicose veins, chronic seromas.¹⁴ Commonly used agents for sclerotherapy are talc, doxycycline, ethanol, erythromycin, fibrin glue and bleomycin.¹⁵ The use of sclerosants can be attempted for treating certain cases before a surgical intervention considered. Side effects following use of sclerosants are skin necrosis and rarely allergic reactions in the form of systemic inflammatory response syndrome (seen rarely with talc).¹⁴

As sclerotherapy has been found to be effective for the management of chronic seromas and since the progression of MLL and seroma progress along the same lines, it can be used to address the problem of MLL. It is a minimally invasive procedure with infrequent complications to tackle MLL. Randomised controlled trials are needed to evaluate the response in different scenarios and to establish treatment guidelines.

Learning points.

• Early diagnosis is crucial to prevent complications such as contour deformity and skin necrosis.

• If treatment is initiated early (before formation of capsule) conservative management by compression with might be useful.

• If capsule has formed or the swelling is recurrent, percutaneous aspiration and sclerotherapy using tetracyclines helps in complete resolution of swelling without need of surgery and thus avoid scar.