A classification of abdominal lymphatic perfusion patterns after Fontan surgery

Abstract

OBJECTIVES Complications after Fontan surgery have been associated with arise and classification of abnormal thoracic lymphatic perfusion pattern. This study compiles abnormal abdominal lymphatic perfusion patterns and investigates their impact on serum protein readings. METHODS We performed a retrospective analysis of patients who underwent magnetic resonance imaging with T2-weighted lymphatic imaging and serum protein measurements 6 months after having Fontan surgery. The abdominal lymphatic images were classified according to the anatomical lymphatic drainage patterns into 2 categories: (1) para-aortic (types 1–4); (2) portal-venous (types 1–3). Thoracic lymphatic images were classified (types 1–4) as described earlier. RESULTS A total of 71 patients were included in the study. Para-aortic lymphatic perfusion patterns were classified as type 1 in 4, type 2 in 13, type 3 in 37 and type 4 in16 out of 71 patients. Portal-venous lymphatic perfusion patterns were classified as type 1 in 20, type 2 in 10 and type 3 in 41 patients. Thoracic lymphatic perfusion patterns were classified as type 1 in 8, type 2 in 11, type 3 in 39 and type 4 in 13 patients. The serum protein level was 66 (interquartile range: 7.5) g/l (< standard value in 37%). Higher-grade para-aortic (p = 0.0062), portal-venous (p = 0.022) and thoracic (p = 0.011) lymphatic abnormalities were correlated with lower total serum protein levels. Higher ratings of para-aortic lymphatic abnormalities were significantly associated with higher ratings of portal-venous abnormalities (p < 0.0001). Ratings of para-aortic and portal-venous classifications were correlated with the thoracic classification (p < 0.001). CONCLUSIONS Abnormal abdominal lymphatic perfusion patterns can be classified according to anatomical structures with increasing severity. Higher grade abdominal and thoracic lymphatic perfusion patterns are associated with lower serum protein values.

Serial T2-Weighted Thoracic and Abdominal Lymphatic Imaging in Fontan Patients—New Insights into Dynamics of Lymphatic Abnormalities after Total Cavopulmonary Connection

“…The development of lymphatic abnormalities has been associated with chronic venous stasis, secondary to increased central venous pressure (CVP) and increased lymph production, leading to lymphatic congestion in the univentricular circulation. A classification for thoracic lymphatic abnormalities was described by Biko et al, and recently, abdominal lymphatic abnormalities have been classified by our group for improved clinical quantification [ 5 , 9 ]. The abdominal lymphatic perfusion pattern is of particular interest after TCPC due to the role of the liver, which produces about 25–50% of the lymph flow in the thoracic duct.…”

“…This technique acquires images during breath holding; an intershot motion correction is applied for reducing image artifacts due to pulsation, intestinal peristalsis, or residual respiratory movement. Scan parameters were as follows: total measurement time approximately 3 min, coronal orientation with complete coverage of the neck, chest and abdomen, slice thickness 6 mm and slice gap of 1.5 mm, in-plane resolution 1.1 × 1.1 mm 2 , time to echo 110 ms, time to repetition 1800 ms and flip angle 160 degrees [ 9 ].…”

“…T2-weighted images were analyzed with the same software. All measurements were performed as previously described [ 9 ].…”

“…Abdominal lymphatic abnormalities were graded according to the recently described classification [ 9 ].…”

“…There was an urgent need to extend this classification to the abdominal cavity for this patient population. Our group recently suggested a new classification for abdominal lymphatic abnormalities, including para-aortic and portal-venous lymphatic perfusion pattern [ 9 ]. This is important for two reasons: first, the lymphatic system is an interconnected network between the chest and abdominal cavity, and second, many patients present with abdominal symptoms, including ascites or protein-losing enteropathy (PLE) [ 10 , 11 ].…”