Role of Interventional Radiology in the Management of Vascular Lesions around the Knee Joint: A Series of Four Cases

1. Assistant Professor, Department of Interventional Radiology, Dr. D.Y. Patil Medical College, Hospital and Research Centre, Pimpri, Pune, Maharashtra, India. 2. Head, Department of Interventional Radiology, Dr. D.Y. Patil Medical College, Hospital and Research Centre, Pimpri, Pune, Maharashtra, India. 3. Senior Resident, Department of Interventional Radiology, Dr. D.Y. Patil Medical College, Hospital and Research Centre, Pimpri, Pune, Maharashtra, India. 4. Senior Resident, Department of Interventional Radiology, Dr. D.Y. Patil Medical College, Hospital and Research Centre, Pimpri, Pune, Maharashtra, India.

Abstract

The soft tissue lesions around the knee range from congenital, traumatic, and vascular to neoplastic in aetiology. The various imaging modalities employed for diagnostic work-up include plain radiographs, ultrasonography, Computed Tomography (CT) scan, and Magnetic Resonance Imaging (MRI). Based on the peculiar imaging findings, the differential diagnosis can be narrowed down; however, the final diagnosis relies on histopathological findings. Some of the highly vascular lesions are arteriovenous malformation, malignant fibrous histiocytoma, haemangiopericytoma, and synovial sarcoma. The abundant neovascularity within these lesions poses a major problem during surgery due to potential blood loss. Presurgical interventional management in the form of endovascular embolisation significantly reduces intraoperative blood loss. Here, four different cases, one of each type, presenting as highly vascular lesions around the knee joint, were successfully managed with endovascular embolisation.

Embolisation, Haemangiopericytoma, Malignant fibrous histiocytoma, Synovial sarcoma, Venous malformation

Lesions around the knee can have varying underlying aetiologies. Among them, highly vascular lesions include arteriovenous malformations, haemangioendothelioma, haemangiopericytoma, malignant fibrous histiocytoma, synovial sarcoma, rhabdomyosarcoma, and angiosarcoma. For the treatment of these lesions, surgery has been the standard approach for many years (1). However, new endovascular techniques have been introduced and have proven to be as effective as open surgery. Recently, their usage has been increasing (1). Due to the rich neovascularity within these lesions, they are prone to repeated bleeding with mild trauma and during surgery. Therefore, presurgical interventional management in the form of endovascular embolisation significantly reduces perioperative blood loss and patient morbidity (1).

Case Report

Case 1

Synovial sarcoma: A 22-year-old female patient presented with complaints of painful swelling in the posterior aspect of her left knee for the past eight months. On clinical examination, the swelling measured approximately 5×5 cm and was located on the posterior aspect of the left knee joint, with prominent superficial veins. There was no significant limitation in the movement of the knee joint. Palpation of the swelling revealed warmth and tenderness. The peripheral pulses of the posterior tibial and dorsalis pedis arteries were weak, but there was no neurological deficit.

A lateral view radiograph showed soft tissue swelling (Table/Fig 1). Ultrasound (US) revealed a predominantly hypoechoic lesion (Table/Fig 2)a with significant vascularity on Doppler (Table/Fig 2)b, along with encasement of the popliteal artery (Table/Fig 2)c,d. MRI revealed a heterogeneous signal intensity lesion. On the T1W sequence, it appeared nearly isointense to the adjacent muscles (Table/Fig 3)a. On the T2W sequence, the lesion exhibited a central hyperintense necrotic component (Table/Fig 3)b. There were no haemorrhages or calcifications within the lesion on the gradient echo sequence (Table/Fig 3)c. On T1W fat-suppressed images, the lesion appeared predominantly hyperintense compared to the surrounding muscles (Table/Fig 3)d. Post-gadolinium fat-suppressed T1W sequences (Table/Fig 3)e revealed heterogeneous enhancement of the lesion, with a non enhancing central necrotic component and no obvious intra-articular extension.

Preoperative embolisation: Retrograde left femoral arterial access was achieved using a 5F vascular sheath. A catheter-guide wire combination was used, and a crossover was performed at the aortic bifurcation to gain access to the left Superficial Femoral Artery (SFA). Angiograms were taken, revealing displacement of the distal popliteal artery and its bifurcation by the lesion. Multiple branches from the popliteal artery, including the anterior and posterior tibial arteries and peroneal artery, were found to supply the lesion (Table/Fig 4)a, resulting in multiple sites of abnormal vascular blush. Embolisation was carried out using 100-micron Polyvinyl Alcohol particles (PVA) through a coaxial 2.9F microcatheter via transarterial access. A final check angiogram was performed with the catheter tip in the distal SFA, showing a significant reduction in the abnormal vascular blush (Table/Fig 4)b, along with patent and densely filling anterior and posterior tibial as well as peroneal arteries (Table/Fig 4)c, indicating the absence of arteriovenous shunting within the lesion. A repeat US examination the following day (Table/Fig 5) revealed a significant reduction in the vascularity of the lesion. The lesion was excised with an intraoperative blood loss of approximately 800 mL. The histopathological diagnosis confirmed synovial sarcoma with a predominant mesenchymal element in the form of spindle cells after biopsy. The patient underwent postsurgery radiotherapy and remained asymptomatic during a three-month follow-up period.

Case 2

Haemangiopericytoma: A 30-year-old female patient presented with complaints of pain and swelling in the left popliteal region for 5-6 months. There was no history of trauma. On clinical examination, the swelling measured approximately 10×5 cm and was located on the posterior aspect of the left knee joint. There was a mild limitation in the movement of the joint, and mild tenderness was present upon palpation. The peripheral pulses of the posterior tibial and dorsalis pedis arteries were normal.

Radiographs revealed abnormal soft tissue density in the popliteal region with no bony abnormalities (Table/Fig 6). US showed an irregular, heterogeneous, predominantly hypoechoic lesion, which encased and displaced the distal popliteal artery and its branches. Significant vascularity within the lesion was observed on Doppler examination (Table/Fig 7). CT angiography was performed, revealing a large, heterogeneous, intensely enhancing mass that encased and displaced the popliteal vessels. However, the vessels remained patent, and there was normal contrast filling of the Anterior Tibial Artery (ATA), Posterior Tibial Artery (PTA), and peroneal arteries (Table/Fig 8). Due to the tumour vascularity, the patient was referred for preoperative embolisation. The transarterial embolisation procedure performed in this case was similar to the aforementioned case (Table/Fig 9)a,b. The embolisation agent used was 100-micron PVA via transarterial access.

The intraoperative blood loss was approximately 650 mL. Histopathological examination of the operative specimen confirmed the diagnosis of haemangiopericytoma. The patient received radiotherapy postoperatively. After six months of follow-up, an MRI revealed postoperative changes without any recurrence (Table/Fig 10).

Case 3

Malignant fibrous histiocytoma: A 28-year-old female presented to the emergency department with active bleeding from a tumour lesion around the right knee joint, following minor trauma. The lesion had been present for one year, slowly growing. The bleeding continued despite the application of a tight compression bandage. Detailed history revealed a diagnosed case of malignant fibrous histiocytoma. On clinical examination, the swelling measured approximately 8×5 cm and was ulcerated, with active bleeding from one site. Joint movements were restricted, and tenderness was present. Knee joint effusion was also observed.

The transarterial embolisation procedure performed in this case was similar to the aforementioned case (Table/Fig 11). The embolisation agent used was a mixture of Lipiodol and n-butyl cyanoacrylate glue in a 2:1 proportion, along with PVA particles, administered via transarterial access. A repeat US examination was performed one week after embolisation, revealing a significant reduction in vascular spaces and a decrease in the size of the swelling. The patient was then started on radiotherapy without any further episodes of bleeding.

Case 4

Venous malformation: A 23-year-old male patient presented with complaints of pain and swelling in the right lower thigh for three years. The swelling gradually increased in size. On clinical examination, the swelling was observed in the supra-patellar region of the right lower thigh, measuring approximately 6×8 cm. Upon palpation, it was partially compressible and reducible in size with a refill upon pressure release. There was no significant limitation in the movement of the knee joint, and the peripheral pulses of the posterior tibial and dorsalis pedis arteries were normal.

An X-ray revealed abnormal soft tissue density in the suprapatellar region (Table/Fig 12). US revealed a lesion with multiple compressible vascular spaces (Table/Fig 13)a,b, showing internal low peak systolic velocity blood flow. MRI showed a relatively well-defined lobulated, heterogeneous signal intensity lesion involving the inferior-medial aspect of the thigh. The lesion displaced the adjacent muscles and appeared hyperintense to muscle on T1W (Table/Fig 14)a, hyperintense on T2W (Table/Fig 14)b and fat-suppressed T1W sequences (Table/Fig 14)c, with the presence of multiple signal voids. The lesion also showed some hyperintense fatty components on the T1W sequence. Post-gadolinium scan revealed strong enhancement (Table/Fig 14)d, with retention of the contrast on a 30-minute delayed scan (Table/Fig 14)e. Based on these imaging findings, the diagnosis of venous malformation was confirmed.

Preoperative embolisation: Under US guidance, the vascular spaces inside the lesion were punctured using a 22G scalp vein set. Retrograde free flow of blood was ensured, indicating the position of the needle tip within the vascular spaces. Slow injection of Sodium tetradecyl sulfate (30 mg/mL) mixed with a contrast agent was performed under fluoroscopic guidance into the cannulated vascular spaces (Table/Fig 15). These steps were repeated until most of the vascular spaces were cannulated and embolised. A repeat US examination one week postembolisation revealed a significant reduction in patent vascular spaces and a decrease in the overall vascularity of the swelling (Table/Fig 16).

Discussion

Synovial sarcoma: Synovial sarcomas are malignant tumours commonly seen in adolescents and young adults. About 60% of synovial sarcomas are localised in the lower limbs. The incidence is usually 0.81-1.42 (2). Their development is typically extra-articular. They can be found anywhere in the body (10% of all soft tissue tumours), but most of them arise in the extremities, particularly near the knee joints (2). The characteristic finding on imaging is the presence of intratumoural calcification or ossification (3). Angiography prior to definitive surgery helps differentiate the lesion, evaluate tumour vessels, and prevent bleeding through embolisation (4). Surgery is the treatment modality of choice, but the tumour often recurs even after wide resection (3). The prognosis of synovial sarcoma is poor, with almost always recurring and five-year survival rates ranging from 25 to 50% depending on the series (2). The general principles of transarterial embolisation treatment involve hindering or reducing blood flow to the tumour, resulting in tumour reduction or destruction. This is achieved by injecting embolic agents into the arteries that supply blood to the tumour (2). Embolisation may be used alone or in combination with other treatments such as surgery, radiation therapy, or systemic therapy (2).

Vascular malformations: Vascular malformations encompass a wide range of anomalies, for which different classification systems have been proposed over time. The important one is given by the International Society for the Study of Vascular Anomalies (ISSVA), based on cellular features, flow characteristics, and clinical behaviour (5). These lesions, though congenital, are usually asymptomatic at birth and become symptomatic later in adolescence or adult life due to rapid growth, vascular engorgement caused by thrombosis, trauma, infection, or hormonal fluctuations. Symptoms may include ulceration, haemorrhage, cardiac failure, and unwanted cosmetic consequences (6). Various imaging modalities, such as radiography, Doppler US, CT scan, and MRI, are used, with MRI playing a pivotal role (6). Angiography is helpful for anatomical assessment and direct puncture of the nidus, which can evaluate the volume and flow pattern of these lesions (6). Endothelial cells play a role in vascular remodeling, especially at the venous stump, which recruits collateral flow. Interventional techniques involve the use of therapeutic agents targeting the venous stump while avoiding harm to adjacent tissue (7).

Haemangiopericytoma: Haemangiopericytoma is a highly vascular tumour that can be found anywhere in the body where there are capillaries. The cell of origin is the pericytes, contractile spindle cells that surround capillaries and post capillary venules (8). It is more common in middle-aged individuals (9). The lower extremity is affected in 35% of cases. It typically presents as an asymptomatic mass or may cause pressure symptoms if it is large enough (8). Haemangiopericytoma is a highly vascular tumour with clinically significant arteriovenous shunting. Angiographically, the typical feature of haemangiopericytoma is a hypervascular lesion with a few feeder arteries that enter the mass, along with radially arranged branching vessels around and inside the tumour. Longstanding, well-demarcated tumour staining and early opacification of veins due to arteriovenous shunting are also observed [10,11]. Smith RB et al., reported the use of preoperative arterial embolisation in the management of a large pelvic haemangiopericytoma that was previously considered unresectable (12). Surgery is the treatment of choice, but local recurrence is not uncommon.

Malignant Fibrous Histiocytoma (MFH): MFH is predominantly seen between the 6th and 7th decades of age (13). The most common site of origin is the extremities (13). MFH can be a primary tumour or can arise secondarily at sites of previous radiation therapy, surgery, fractures, osteonecrosis, Paget’s disease, chronic osteomyelitis, and various benign bony lesions such as fibrous dysplasia, enchondroma, non ossifying fibroma, etc. (14). Primary MFH can arise from the soft tissue or bones. On angiography, the lesion shows diffuse neovascularity with multiple areas retaining the stain and arteriovenous shunting. Clinical and radiological features of vascular lesions around the knee joint are discussed in (Table/Fig 17).

Role of preoperative embolisation: Successful preoperative embolisation is defined as catheterisation of the tumour-supplying arteries with obliteration of more than 70% of the tumour stain. The goal of preoperative embolisation is to exclude the tumour capillary bed, not just the major arterial feeders. Preoperative embolisation helps reduce intraoperative blood loss, improves visualisation during surgery, and facilitates en-bloc resection (15).

In a study by Jha R et al., preoperative embolisation of bone tumours was found to be a safe and effective adjunct to the surgical management of primary bone tumours, resulting in a reduction in intraoperative blood loss and transfusion volume (16). Manke C et al., reported a significant reduction in intraoperative haemorrhage in patients who underwent preoperative embolisation for spinal metastases from renal cancer using PVA particles, compared to patients who underwent surgery alone (17). Kickuth R et al., also reported significantly reduced intraoperative blood loss ranging from 200-4000 mL in patients who underwent preoperative embolisation for bone tumours (18). Wong SJ et al., found that intraoperative blood loss ranged from 150 mL to 6,900 mL, with a mean of 1,173 mL and a median of 500 mL in patients who underwent preoperative embolisation for musculoskeletal tumours (15).

Other advantages of preoperative embolisation include a reduction in the amount of viable tumour, a decrease in the rate of tumour growth, and a potential reduction in the need for radiotherapy and chemotherapy (13). Tumour embolisation can also be performed as a standalone procedure in a palliative setting for pain relief (17), reduction of tumour volume (18), or in combination with ablation/cementoplasty (19). Major complications following preoperative tumour embolisation are rare. The most common complications observed are non target embolisation and postembolisation syndrome (20).

Conclusion

Embolisation for highly vascular musculoskeletal lesions is feasible, safe, and highly effective as a primary treatment modality and also as a preparation for definitive surgery. Preoperative embolisation helps reduce intraoperative blood loss, improves visualisation during surgery, and facilitates en-bloc resection. Further large scale studies are needed to validate these results.

DOI and Others

DOI: 10.7860/JCDR/2023/65197.18635

Date of Submission: May 03, 2023
Date of Peer Review: Aug 07, 2023
Date of Acceptance: Sep 22, 2023
Date of Publishing: Oct 01, 2023

AUTHOR DECLARATION:
• Financial or Other Competing Interests: None
• Was informed consent obtained from the subjects involved in the study? Yes
• For any images presented appropriate consent has been obtained from the subjects. Yes

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EMENDATIONS: 6