Treatment of lymphatic system disorders includes drainage, Denver shunt, pleurodesis, abla-tion of lymphocele, and embolization for lymphatic vessel or thoracic duct. In most cases, the interventional treatment is for lymph leakage. In order to identify the leakage site, a combi-nation of survey of fluid collection by drainage and lymphatic imaging is required. Knowledge of lymphatic anatomy and imaging are necessary to start lymphatic intervention. In the technique of pedal lymphangiography which is the traditional method, a tiny lymphatic duct in the dorsal legs must be exposed and then this duct is punctured using a small bore needle. Recently, it is difficult to learn this technique, and pedal lymphangiography has been replaced by intranodular lymphangiography. However, this technique is sometimes required in cases in which the in-guinal or femoral lymph nodes cannot be detected or the leakage site is in a lower limb. In this paper, we will present the anatomy of the lymphatic system and pedal lymphan-giography.
Intranodal lymphangiography (IL) a recently introduced technique provides a diagnostic and therapeutic method of lymphatic disorders. The benefits of this technique include reduced technical difficulty and shorter procedure duration, as compared to traditional pedal lym-phangiography (PL). The scope of this lecture is to understand the fundamentals and advanced techniques of performing lymphangiography as well as important points for safe and proper use of Lipiodol®. [Intranodal lymphangiography] The original procedure of IL first described in 1952 by Bruun et al. is characterized by a direct puncture of enlarged lymph nodes under palpation. As it was not performed under ultrasound guidance, the indications for IL were limited and less preferred than PL. However, the circumstances changed after 45 years when Rajebi et al. and Nadolski et al. reported the effectiveness of IL in the pediatric field; they started to perform IL under US guidance, and since then, IL has become popularized as a simple method for evaluation and intervention of lymphatic disorders. [Direct Puncture Retrograde Thoracic Duct Access] This technique is an alternative method of thoracic duct (TD) intervention first reported in 2016 by Carlos J. et al. It is characterized by direct insertion into the venous system at the base of the left neck during lymphangiography or US guidance. This technique is especially useful to visualize the terminal portion of the TD, which is located between the internal jugular vein and the left vertebral vein. The superficial location of the TD and the high accuracy in identifying the TD in the left neck under US guidance provides sufficiently high visibility to access the TD under iodine-based lymphan-giography. Thus, this method is safely applicable for cases with right-left shunt without taking the risk of systemic embolization.
Loss of chyle into the thoracic/peritoneal cavity can lead to serious life-threatening conse-quences because of the significant loss of fluid, plasma protein, fats and immunoregulatory lymphocytes, and clinical features of severe malnutrition, hyponatraemia, acidosis, hy-pocalcaemia and susceptibility to infection. We reported that lymphangiography was effective not only for diagnosis but also as treatment for various chyle leakages. Since then, reports on lymphatic interventions including therapeutic lymphangiography for lymphatic leaks and thoracic duct embolization (TDE) for postoperative chylothorax have been increasing in number. However, postoperative lymphatic leakage remains a challenging clinical problem with high mortality in post esophageal surgery. Despite this clinical problem, an animal model for lymphatic interventions has not been developed so far. There have been a few reports on a swine model of lymphangiography and TDE. It is true that a swine model mimics the human lym-phatics. However, a swine model has higher maintenance costs and is harder to handle. Spe-cialized infrastructure and trained personnel are needed for experimental study in swine. On the other hand, rabbits are inexpensive, easy to manage in a laboratory setting and have an organ system like that of humans. For lymphatic interventions and future lymphatic imaging, detailed lymphatic anatomical features in a rabbit model should be elucidated. Here, we would like to introduce therapeutic lymphangiography for various lymphatic leaks, and feasibility of lym-phangiography and the visibility of the lymphatic system on post-lymphangiographic multi-detector row CT for preclinical lymphatic interventions in a rabbit model.
The number of publications regarding thoracic duct embolization is booming. It was only 2250 papers between 1975-2000, doubled (4720) between 2000-2010 and has now reached nearly 7000 papers published within the last 8 years. The thoracic duct is the body's largest lymphatic conduit, draining upwards of 75% of lym-phatic fluid and extending from the cisterna chyli to the left jugulovenous angle. Thoracic duct embolization for chylous thoracic effusion is emerging as a result of the increasing popularity of minimally invasive neck and thoracic area surgery. Chylous leakage and chylous ascites may result in significant morbidity and mortality. Although conservative dietary treatments and invasive open surgery methods exist, the majority of tho-racic duct injury require embolization in the interventional suite. Thoracic duct embolization requires a combination of very basic angiography and interventional radiology skills, such as fluoroscopic guidance, ultrasound guidance, percutaneous access of cisterna chyli or lower thoracic duct followed by wiring and cannulation, embolization with coils and glue. Thoracic duct embolization is an emerging technique; however, the required skills are all well known to us. Once one understands the anatomy and pitfalls of this procedure, Thoracic duct embolization should not be a challenging procedure.
One of the important functions of the lymphatic system is maintenance of fluid balance, and lymphatic leakage after surgery potentially becomes a critical condition. Interventional techniques could not treat lymphatic leakage effectively mostly due to the lack of clinical imaging. However, the recently developed intranodal lymphangiography provides new insight into lymphatic intervention. At first, thoracic duct embolization has become the method of choice for the treatment of patients with chylothorax. Abdominal lymphatic leakage as a complication of abdominal and pelvic surgery is an uncommon but difficult-to-treat condition when conservative measures have failed. Embolization and sclerotherapy are also very useful for refractory lymphatic leakage. These current advances will open up new treatments and diag-nostic opportunities for abdominal lymphatic leakage.
A man in his 60s was admitted to our hospital for the treatment for post-operative intrahepatic recurrence of hepatocellular carcinoma with transcatheter arterial chemoembolization (TACE). During hepatic arteriography, angiospasm of the common hepatic artery occurred. We then performed intra-arterial injection of epirubicin-lipiodol suspension via the right inferior phrenic artery as an alternative treatment for TACE. Anorexia appeared at 12 days after the initial an-giography; contrasted-enhanced CT revealed a 17-mm aneurysm in the pancreatic head, a hematoma around the aneurysm, and a passage disorder in the third portion of the duodenum. Emergency superior mesenteric arteriography demonstrated a saccular aneurysm of the anterior inferior pancreatico-duodenal artery near the pancreatic head. Coil embolization was performed for the ruptured aneurysm using the isolation technique. Contrast-enhanced CT after coil embolization proved disappearance of the peripancreatic hematoma, and the passage of the duodenum improved. In this case, it was considered that retrograde blood flow in the pancreatic arterial arcade increased due to angiospasm of the hepatic artery, and an aneurysm developed in a very short period.
Recently, transcatheter arterial embolization (TAE) including coil packing for visceral artery aneurysms (VAAs) has been widely used as a treatment alternative to surgical ligation. However, recanalization or coil compaction may occur in approximately 35% of cases after packing using bare platinum coils. Therefore, high packing density of 24 % for an aneurysmal lumen is re-quired minimally for stable occlusion. When tight packing is planned before the procedure, not only coil type but also catheter selection should be also well-considered in advance to obtain a good support. The selections among various devices, including guiding catheter and the compatibility between the coil and the microcatheter, are essential to smooth delivery of coils without any trouble including stacking, snaking, or pushing back of the coils. In addition, the order of many various detachable coils is important for tighter packing. In this article, we report some technical tips focusing on coil packing of visceral artery aneurysms for acquiring higher packing density.