Central Lymphatic Imaging in Adults with Spontaneous Chyluria

Tran Quoc Hoa,1 Nguyen Ngoc Cuong,2 Nguyen Cong Hoan,3 Nguyen Quang Trung,2 Thieu Thi Tra My,4 Nguyen Ngoc Anh,5 Hoang Long1 1Surgery Urology, Hanoi Medical University Hospital, Hanoi Medical University, Hanoi, Vietnam; 2Radiology Center Hanoi Medical University Hospital, Hanoi Medical University, Hanoi, Vietnam; 3Outpatient department, Hanoi medical university hospital, Hanoi medical university, Hanoi, Vietnam; 4Radiology Department, Vinmec Times city Interational Hospital, Hanoi, Vietnam; 5Anatomy Department, Hanoi Medical University, Hanoi, VietnamCorrespondence: Nguyen Ngoc Cuong, Radiology center, Hanoi medical university hospital, No. 1, Ton That Tung Street, Dong Da District, Hanoi, Viet Nam, Tel +84965131314, Email [email protected]: Chyluria is a rare condition primarily prevalent in developing countries in tropical regions. In chyluria, there exists the communication between lymphatic vessels and the urinary tract, but the specific mechanism of this communication remains undocumented. The objective of this study was to assess the morphology of the main lymphatic vessels including the uro-lymphatic fistula, the thoracic duct using Magnetic Resonance Lymphangiography (MRL) and Intranodal Lymphangiography (IL).Materials and Methods: A retrospective study spanning five years, from January 2020 to January 2024, included 43 patients diagnosed with chyluria through cystoscopy and quantitative urine testing for triglycerides. These patients underwent MRL and then IL for uro-lymphatic fistula embolization.Results: The study involved 43 patients with an average age of 66.1 ± 19.5 years, with a male-to-female ratio of 1:2. Uro-lymphatic fistula occurred predominantly in the left kidney (72.1%), followed by the right kidney (20.9%), and both sides (7%). MRL imaging showed the thoracic duct in 100% of cases but visualized only 84.5% of the uro-lymphatic fistulas. In contrast, IL imaging showed the thoracic duct in 51.5% of patients but visualized uro-lymphatic fistulas in 100% of cases. In the procedure of IL, the average visualization time of the thoracic duct was 45 minutes, with a range of 35 to 69 minutes.Conclusion: MRL and IL complement each other in diagnosing the main lymphatic vessels in chyluria patients. The observed circulatory stasis in the thoracic duct supports the hypothesis that it contributes to increased pressure in the thoracic duct and the formation uro-lymphatic fistula as collateral circulations.Keywords: chyluria, MR lymphangiography, intranodal lymphangiography, uro-lymphatic fistul

Isotopic techniques to measure N2O, N2 and their sources

GHG emissions are usually the result of several simultaneous processes. Furthermore, some gases such as N2 are very difficult to quantify and require special techniques. Therefore, in this chapter, the focus is on stable isotope methods. Both natural abundance techniques and enrichment techniques are used. Especially in the last decade, a number of methodological advances have been made. Thus, this chapter provides an overview and description of a number of current state-of-theart techniques, especially techniques using the stable isotope 15N. Basic principles and recent advances of the 15N gas flux method are presented to quantify N2 fluxes, but also the latest isotopologue and isotopomer methods to identify pathways for N2O production. The second part of the chapter is devoted to 15N tracing techniques, the theoretical background and recent methodological advances. A range of different methods is presented from analytical to numerical tools to identify and quantify pathway-specific N2O emissions. While this chapter is chiefly concerned with gaseous N emissions, a lot of the techniques can also be applied to other gases such as methane (CH4), as outlined in Sect. 5.3

Minimally Invasive Treatment of Chyle Leak After Thyroidectomy and Cervical Lymph Node Dissection in Patients with Thyroid Carcinoma: Results of a Study Involving 36 Patients

Nguyen Ngoc Cuong,1,* Le Hoan,2,* Thieu Thi Tra My,3 Doan Tien Luu,1 Le Tuan Linh,1 Pham Hong Canh,1 Trieu Quoc Tinh,1 Tran Nguyen Khanh Chi,1 Nguyen Quang Trung,1 Tran Quoc Hoa4 1Diagnostic Imaging and Interventional Center, Hanoi Medical University Hospital, Ha Noi, Viet Nam; 2Respiratory Department, Hanoi Medical University Hospital, Ha Noi, Viet Nam; 3Diagnostic Imaging and Nuclear Medicine Department, Vinmec Times City International Hospital, Ha Noi, Viet Nam; 4Urology Surgery department, Hanoi Medical university, Ha Noi, Viet Nam*These authors contributed equally to this workCorrespondence: Nguyen Ngoc Cuong, Diagnostic Imaging and Interventional Center, Hanoi Medical University Hospital, No. 1, Ton That Tung, Dong Da, Ha Noi, Viet Nam, Email [email protected]: Chyle leak (CL) after head and neck surgery is a rare but well-known complication. In patients with high-output leakage, the treatment can be complicated. This study aims to report on a recent innovation in lymphatic intervention for treating such patients.Materials and Methods: A retrospective review of 36 patients with chyle leak after neck surgery for thyroid cancer was conducted to assess the efficacy of percutaneous lymphatic embolization and thoracic duct (TD) disruption.Results: Antegrade catheterization of the thoracic duct was achieved in 31 of 36 patients (86.1%). Therefore, embolization of the thoracic duct and thoracic duct branches was performed in 26 and 5 patients, respectively. In 5 cases of unsuccessful antegrade catheterization into the thoracic duct, transcervical access embolization was performed in 2 patients, and TD disruption (TDD) was performed in 3 patients. The pooled overall technical success rate of lymphatic embolization was 33/36 patients (91.7%). One patient who underwent thoracic duct embolization (TDE) with technical success (1/33 patients) but clinical failure had additional treatment directly sclerosing the TD under computed tomography scan. Cervical fluid collection sclerotherapy was done in 7 patients as an additional treatment. Resolution of the chyle leak after procedures was observed in all patients (100%). The mean time to resolution was 3 days (1– 7 days). There was no complication intra and after procedures.Conclusion: TDE, selective TD branches embolization and TDD are safe and effective minimally invasive treatments for CL post-surgery for thyroid carcinoma. Sclerosing cervical fluid collection contributes to clinical success.Keywords: thyroid cancer, thyroidectomy, chyle leak, thoracic duct embolization, thoracic duct disruption, sclerotherap