Current diagnostic and therapeutic strategies for the management of lymphatic insufficiency in patients with hypoplastic left heart syndrome

Abstract

Children with hypoplastic left heart syndrome share unique hemodynamic features that alter lymphatic integrity at all stages of palliation. Lymphatic congestion is almost universal in this patient group to some extent. It may lead to reversal of lymphatic flow, the development of abnormal lymphatic channels and ultimately decompression and loss of protein rich lymphatic fluid into extra lymphatic compartments in prone individuals. Some of the most devastating complications that are associated with single ventricle physiology, notably plastic bronchitis and protein losing enteropathy, have now been proven to be lymphatic in origin. Based on the new pathophysiologic concept new diagnostic and therapeutic strategies have recently been developed. Dynamic contrast magnetic resonance lymphangiography is now mainstay in diagnosis of lymphatic insufficiency and allows a thorough assessment of anatomy and function of the main lymphatic compartments through intranodal, intrahepatic and intramesenteric lymphatic imaging. Contrast enhanced ultrasound can evaluate thoracic duct patency and conventional fluoroscopic lymphangiography has been refined for evaluation of patients where magnetic resonance imaging cannot be performed. Novel lymphatic interventional techniques, such as thoracic duct embolization, selective lymphatic duct embolization and liver lymphatic embolization allow to seal abnormal lymphatic networks minimally invasive and have shown to resolve symptoms. Innominate vein turn-down procedures, whether surgical or interventional, have been designed to reduce lymphatic afterload and increase systemic preload effectively in the failing Fontan circulation. Outflow obstruction can now be managed with new microsurgical techniques that create lympho-venous anastomosis. Short term results for all of these new approaches are overall promising but evidence is sparse and long-term outcome still has to be defined. This review article aims to summarize current concepts of lymphatic flow disorders in single ventricle patients, discuss new emerging diagnostic and therapeutic strategies and point out lacks in evidence and needs for further research on this rapidly growing topic.

Keywords: dynamic contrast magnetic resonance lymphangiography; fontanoperation; hypoplastic left heart syndrome; innominate vein turn-down procedures; lymphatic insufficiency; lymphatic interventional techniques; plastic bronchitis; protein-losingenteropathy.

Figure 1

Effect of single ventricle palliation on lymphatic flow. (A) At birth lymphatic flow is normal. (B) After the Glenn operation the higher INNV pressure decreases lymphatic drainage capacity. (C) The elevated CVP after the Fontan operation additionally increases lymph production in the liver. INNV, innominate vein; CVP, central venous pressure.

Figure 2

Pulmonary lymphatic perfusion syndrome. (A) Coronal projection of intranodal, intrahepatic and intramesenteric dynamic contrast magnetic resonance lymphangiography and (B) corresponding MIP T2 weighted lymphatic imaging demonstrating retrograde perfusion of the mediastinal, peribranchial- and pulmonary interstitial-lymphatic networks in a 3.2 year old patient with occluded thoracic outlet (type 4). (C) Coronal projection of intranodal dynamic contrast magnetic resonance lymphangiography and (D) corresponding MIP T2 weighted lymphatic imaging demonstrating a double thoracic duct in a 2.5 year old patient with the left duct supplying the lungs (type 3). (E) Typical airway cast in PB. MIP, maximal intensity projection; PB, plastic bronchitis.

Figure 3

Different etiologies of chylothorax. Coronal projection of dynamic contrast magnetic resonance lymphangiography in a a 15 year old patient with (A) traumatic leak (asterixis), in a 7 year old patient with (B) pulmonary lymphatic perfusion syndrome (arrow) and (C) a central lymphatic flow disorder showing dermal backflow (arrowhead) in a 2 months old patient.

Figure 4

DCMRL sequence of all major lymphatic streams in a 7 year old patient with PLE. Coronal projection of (A,B) intrahepatic DCMRL, (C,D) intramesenteric DCMRL, and (E) intranodal DCMRL revealing leakage into the duodenum. DCMRL, dynamic contrast magnetic lymphangiography;.

Figure 5

MIP coronal projection of (A) T2 imaging and (B–D) DCMRL in a 17.9 year old patient with multicompartment lymphatic failure including ascites (arrow), PLE (asterixis). DCMRL, dynamic contrast magnetic resonance lymphangiography; PLE, protein losing enteropathy; DCMRL, dynamic contrast magnetic resonance lymphangiography.

Figure 6

Native T2 weighted lymphangiography coronal projection depicting type 4 lymphatic abnormality with bilateral supraclavicular lymphatic abnormality and lymphatic networks extending into the lung parenchyma in a 13 year old patient.

Figure 7

Treatment algorithm for chylothorax. DCMRL, dynamic contrast magnetic resonance lymphangiography; IH, intrahepathic; IN, intranodal; LVA, lymphovenous anastomosis; TDE, thoracic duct embolization; SLDE, selective lymphatic duct embolization; TD, thoracic duct; TDD, thoracic duct decompression; TDL, thoracic duct ligation; LVA, lympho-venous anastomosis.

Figure 8

Treatment algorithm for plastic bronchitis. DCMRL, dynamic contrast magnetic resonance lymphangiography; IH, intrahepathic; IN, intranodal; LVA, lymphovenous anastomosis; PLPS, pulmonary lymphatic perfusion syndrome; SLDE, selective lymphatic duct embolization; TDE, thoracic duct embolization; TDD, thoracic duct decompression; LVA, lympho-venous anastomosis.

Figure 9

Treatment algorithm for protein losing enteropathy. DCMRL, dynamic contrast magnetic resonance lymphangiography; IH, intrahepathic; IN, intranodal; IM, intramesenteric; TDD, thoracic duct decompression; MCT, medium-chain triglyceride; PLE, protein losing enteropathy.

Figure 10

Treatment algorithm for multicompartment lymphatic failure. DCMRL, dynamic contrast magnetic resonance lymphangiography; IH, intrahepathic; IN, intranodal; IM, intramesenteric; TD, thoracic duct; MCT, medium-chain triglyceride; OHT, orthotopic heart transplant.

Figure 11

Different types of lymphatic interventions. (B) AP fluoroscopic imaging after thoracic duct embolization (arrow) in a 5 year old patient. (A) Corresponding preinterventional IN-DCMRL. (C) MIP coronal projection of IH-DCMRL in a 12 year old patient with plastic bronchitis demonstrating hepatopulmonary connections (arrow). (D) AP fluoroscopic image showing the hepatopulmonary connection after selective embolization (arrow). (E) Coronal projection of intrahepatic dynamic contrast magnetic resonance lymphangiography in a 21 year old patient with PLE demonstrating leak into the duodenum. (F) Fluoroscopic imaging of the duodenum after periduodenal (arrow) lymphatic embolization in the same patient.

Figure 12

Ap fluoroscopic imaging of a 5 year old patient after surgical TD decompression demonstrating an unobstructed shunt (asterixis) between the innominate vein and the atrium. TD, thoracic duct.