New Access Kit for Lymphatic Interventions

SUMMARY Despite the physiologic importance of the lymphatic system (LS), it has been arguably the most neglected part of circulatory system, primarily because of a lack of robust imaging and interventional methods. Traditional pedal lymphangiography (PL; i.e., direct cannulation of the lymphatic vessels), has significant technical, time, cost, and image quality challenges. Recently, the field of lymphatic imaging and intervention underwent revival due to the development of intranodal lymphangiography (IL) and thoracic duct embolization (TDE). IL was developed as a technically simple alternative to pedal lymphangiography. IL is performed by accessing the lymph nodes with a spinal needle using ultrasound guidance. It provides imaging that is superior to PL and is now the leading method of imaging of the lymphatic system worldwide. Although the IL technique has many advantages over PL, there are remaining problems because a spinal needle is not designed specifically for this application. Limitations of IL include: 1) Difficulty of introducing needle into lymphatic node (LN), because of mobility of the LN within the loose subcutaneous tissue; 2) Difficulty in positioning the needle precisely in the central part of the LN; 3) Lack of a stabilization mechanism of the needle in LN during intervention and patient transfer. The last issue results in frequent dislodgement of the needle, greatly impairing the quality of the imaging and decreasing the success of the lymphatic procedures. TDE is a minimally invasive technique developed to treat the pulmonary lymphatic disorders. During TDE, the access to the TD is obtained transabdominally using a long 21-22 G needle. Similarly to the issues with IL listed above, the needle is not specially designed for TD intervention and leads to the following shortcomings: 1) The needles are not sharp enough to traverse the long route of compliant tissue; 2) The needle is not sufficiency rigid, so it is difficult to have fine control of the tip of the needle; 3) The sharp angle of access to the TD makes it difficult to manipulate the wire in the TD, resulting frequently in shearing; and 4) The choice of needle length is very limited. Lymphatic imaging and TD interventions are both time-consuming and technically challenging and remain a major hurdle to the detection and treatment of lymphatic disorders. Therefore, innovative LS access tools are critical to the progress of lymphatic intervention. The goals of the proposal are to determine the safety and effectiveness of novel LN and TD needles in vivo in swine to address the issues above. An innovative lymphatic-specific toolkit has advantages over existing access kits, which is demonstrated by our preliminary data. Due to its simplicity, safety, and effectiveness to access the LS, our new toolkit will have broad utility to enable wider use of diagnostic access and treatments in the LS. This specially designed novel toolkit will considerably improve the success of lymphatic imaging and intervention, enhance patient comfort, increase physician efficiency, and lower medical costs by improving efficiency and efficacy.NARRATIVE Although lymphatic interventions have increased substantially over the last decades worldwide, the lack of dedicated lymphatic intervention tools presents technical challenges in performing the lymphatic procedures and hence has limited diagnosis and interventions for lymphatic disorders. Our project is aimed at developing a novel lymphatic access toolkit to address the existing problems and to facilitate the technical success of lymphatic imaging and intervention, therefore improving clinical success, lower medical costs, and reducing x- ray exposure to patients and physicians through easier and quicker access into lymphatic system.