The role of embolization in musculoskeletal pain management, treatment of haemorrhoidal bleeding and lymphatic interventions were among the highlights of a special session titled The Embolization Vanguard at the Global Embolization Symposium and Technologies (GEST 2016 US, 5-8 May, New York, USA) meeting.
The session also saw presentations on bariatric embolization for weight loss, an update in the treatment of benign prostatic hyperplasia by embolization and intra-arterial treatment for pancreatic cancer.
Yuji Okuno, Department of Orthopedic Surgery, Edogawa Hospital, Tokyo, Japan, reported on the team’s experience in using embolization to manage pain in musculoskeletal diseases.
From 2012 to 2016, the researchers have treated a total of 492 patients including 90 patients for tendinopathy and enthesopathy; 115 patients for musculoskeletal shoulder pain (such as frozen shoulder); 75 patients with knee osteoarthritis and 40 patients for sports injuries. They have also treated 25 patients for persistent pain after joint replacement and 147 other patients including pain in the hip, ankle, wrist, elbow and other areas.
The team from Japan most often use a temporary embolic particle (imipenem/cilastatin sodium) that is approved as an embolic in Japan. This forms small particles (10–70µm) when suspended in 5–10ml of contrast.
In many cases such as frozen shoulder or knee osteoarthritis, patients have mild to severe persistent pain and treatment is often a challenge. Very often with regard to musculoskeletal pain, there are many refractory cases for which there is no optimal treatment that is accepted resulting in a loss of patient quality of life that also has an economic impact.
Okuno and team use a technique called transcatheter arterial microembolization (TAME). They target small diameter abnormal vessels with the treatment goal of not totally occluding the vessels, but to decrease blood flow, while maintaining physiological flow.
“Embolization of abnormal neovessels is believed to relieve pain as it improves inflammatory conditions (that are usually maintained by the abnormal vessels. The procedure is also believed to reduce stimulation from the accompanying nerve fibre as nerve fibres grow around neovessels),” Okuno said.
At three years, data from 24 patients with frozen shoulder shows a decreased mean visual analog scale (VAS) pain score and improved range of motion.
The team has observed that embolization results in a sharp drop in pain scores and gain in functional scores in the patients that they have treated with embolization. Ongoing and future plans include an animal study to investigate the mechanism of action of embolization and to identify the most appropriate embolic material. Future randomised controlled trial comparing TAME vs. other procedure and TAME vs. a sham treatment are needed, Okuno said.
Maxim Itkin, an interventional radiologist, Department of Radiology, Hospital of the University of Pennsylvania, and director of the Center for Lymphatic Imaging and Interventions Program then presented on what the panel noted was pioneering work in the genesis of an entirely new field, the real next frontier, of lymphatic interventions.
“General lymphatic flow physiology was extensively studies in up to the 1970s. There has been 40 years of hiatus due to the absence of lymphatic imaging methods and interventional techniques. In 2012, Nadolski GJ, and colleagues reported on the feasibility ultrasound-guided intranodal lymphangiograms for thoracic duct embolization in the Journal of Vascular and Interventional Radiology (JVIR),” Itkin said.
“Today, therapeutic approaches to lymphatic flow disorders include lymphatic embolization for chylothorax, plastic bronchitis, pulmonary lymphangiomatosis, and chylous ascites. Liver lymphatic embolization is used to treat ascites, protein losing enteropathy and liver lymphorea. Thoracic duct externalisation is used to treat lymphodysplasia,” he added.
Dori et al reported in Circulation in 2016 that in 18 patients treated with plastic bronchitis who were treated with embolization, all patients demonstrated pulmonary lymphatic perfusion. 94% (15 out of 16) showed significant improvement of their symptoms.
Today, Itkin said, there is a 100% success rate in the treatment of traumatic chylothorax, and a 95–100% success rate in the treatment of non-traumatic chylothorax. Also, the aetiology has been outlined and treatment developed with a 94% success rate for plastic bronchitis. Successful treatment has also been developed for chylous ascites. The aetiology has also been discovered and treatment developed for neonatal chylothorax, protein losing enteropathy and pulmonary lymphangioma as well as pulmonary lymphangiomatosis.
“In the future, MRI and lymphatic embolization will aid in the treatment of chronic bronchitis, interstitial lung disease and bronchopulmonary dysplasia. Liver lymphatic embolization will help to treat cardiac ascites, liver cirrhosis ascites and congenital lymphodysplasia. Thoracic duct externalisation will help treat HIV, immunotherapy and T cell depletion therapy,” Itkin concluded.
Vicent Vidal, Department of Radiology, Hôpital de la Timone, Marseille, France, then provided an update on Emborrhoid, a new concept for the treatment of haemorrhoids with arterial embolization. He shared the results of a recent prospective study that employed Emborrhoid as a first-line treatment. After discussion between a proctologist, visceral surgeon and radiologist, 25 patients with disabling, abundant, rectal bleeding were enrolled for embolization. The patients ranged from 30 to 72 years and there were 18 men and seven women at stage II or III of haemorrhoidal disease.
Results from the study showed a technical success of 100%. The overall rate of symptom improvement was found to be 60.1%. Eight patients asked for a repeat embolization.
“The procedure is technically feasible and safe with no complications observed. It can be carried out on an outpatient basis. The clinical success needs to be improved, perhaps by investigating other embolic agents,” Vidal said.