The Role of Interventional Radiologists in the Treatment of Congenital Lymphatic Malformations

Imaging manifestations of head and neck lymphatic malformations: A single-center experience of 170 surgical cases

OBJECTIVES

To discuss the imaging manifestations and the utility of preoperative ultrasonography (US), contrast-enhanced computed tomography (CE-CT) and contrast enhanced magnetic resonance imaging (CE-MRI) in diagnosing the pediatric head and neck lymphatic malformations (HNLMs).

METHODS

We performed a retrospective review of 170 children who were referred to our hospital in the past 9 years for the treatment of HNLMs.

RESULTS

The diagnostic rates of US, CE-CT and CE-MRI were 93.0% (146/157), 94.7% (143/151) and 100% (45/45), respectively. As in multilocular cases, intracystic septa detection rate was 91.5% (130/142), 50.4% (68/135) and 88.1% (37/42), and which had a statistical difference (χ2 = 25.8131, p < 0.05). US showed capsule contents anechoic in 51.0% (80/157) cases, hypoechoic or mixed echoic in 49.0% (77/157) cases, and flocculent or dotted echo floating in 36.9% (58/157) cases. CT showed low density of the capsule contents without enhancement in 69.5% (105/151) cases and mixed density with enhancement in 30.4% (46/151) cases. Liquid-liquid levers were seen in 8.6% (13/151) cases. MRI showed T1WI high signal and T2WI low signal of the capsule contents without enhancement in 28.9% (13/45) cases and mixed density in 71.1% (32/45) cases. Liquid-liquid levers were seen in 46.7% (21/45) cases. There were statistically significant differences between pure HNLMs and intracystic hemorrhage in capsule content (echo, density, signal), enhancement, and liquid-liquid lever (all p < 0.05). Among US, CE-CT and CE-MRI, intracystic hemorrhage diagnostic accuracy had a statistical difference (χ2 = 25.4152, p < 0.05).

CONCLUSIONS

For clinical diagnosis and evaluation of HNLMs, we suggest that US combined with CE-CT for acute cases, and for stable cases, US combined with CE-MRI.

Surgical Treatment of Mesenteric Lymphatic Malformations in Children: An Observational Cohort study

BACKGROUND

Few studies have analyzed the cyst characteristics and complications of mesenteric lymphatic malformations (ML). This study aimed to compare ML's cyst characteristics and preoperative complications at different locations and suggest a modified ML classification for patients requiring surgery.

METHODS

In total, 157 ML patients underwent surgery at Beijing Children's Hospital between January 2010 and December 2021. The cyst characteristics and preoperative complications were reviewed. The surgical methods for ML were analyzed according to the modified ML classification (Type I, n = 87, involving the intestinal wall; Type II, n = 45, located in the mesenteric boundaries; Type III, n = 16, involving the root of the mesentery; Type IV, n = 7, multicentric ML; Type V, n = 2, involving the upper rectum).

RESULTS

Overall, 111 (70.7%) ML were located at the intestinal mesentery and 44 (28.0%) at the mesocolon. Type I and type II ML mainly involved intestinal mesentery (64.9%) and mesocolon (56.8%), respectively (P < 0.001). Microcystic-type ML and ML with chylous fluid were only located in the intestinal mesentery. Intestinal volvulus was only found in patients with ML in the intestinal mesentery (P < 0.001), whereas ML in the mesocolon were more prone to hemorrhage (P = 0.002) and infection (P = 0.005). ML in the jejunal mesentery was an independent risk factor for intestinal volvulus (OR = 3.5, 95% CI 1.5-8.3, P = 0.003). The surgical methods significantly differed between Type I and type II ML (P < 0.001).

CONCLUSIONS

ML at different locations have different characteristics. For patients requiring surgery, the new ML classification can be used to select an appropriate surgical method.

LEVEL OF EVIDENCE

Level III.

Back to the Future II-A Comprehensive Update on the Rapidly Evolving Field of Lymphatic Imaging and Interventions

ABSTRACT

Lymphatic imaging and interventional therapies of disorders affecting the lymphatic vascular system have evolved rapidly in recent years. Although x-ray lymphangiography had been all but replaced by the advent of cross-sectional imaging and the scientific focus shifted to lymph node imaging (eg, for detection of metastatic disease), interest in lymph vessel imaging was rekindled by the introduction of lymphatic interventional treatments in the late 1990s. Although x-ray lymphangiography is still the mainstay imaging technique to guide interventional procedures, several other, often less invasive, techniques have been developed more recently to evaluate the lymphatic vascular system and associated pathologies. Especially the introduction of magnetic resonance, and even more recently computed tomography, lymphangiography with water-soluble iodinated contrast agent has furthered our understanding of complex pathophysiological backgrounds of lymphatic diseases. This has led to an improvement of treatment approaches, especially of nontraumatic disorders caused by lymphatic flow abnormalities including plastic bronchitis, protein-losing enteropathy, and nontraumatic chylolymphatic leakages. The therapeutic armamentarium has also constantly grown and diversified in recent years with the introduction of more complex catheter-based and interstitial embolization techniques, lymph vessel stenting, lymphovenous anastomoses, as well as (targeted) medical treatment options. The aim of this article is to review the relevant spectrum of lymphatic disorders with currently available radiological imaging and interventional techniques, as well as the application of these methods in specific, individual clinical situations.

Understanding Lymphatic Anatomy and Abnormalities at Imaging

Lymphatic abnormalities encompass a wide range of disorders spanning solitary common cystic lymphatic malformations (LMs) to entities involving multiple organ systems such as lymphangioleiomyomatosis. Many of these disorders are rare, yet some, such as secondary lymphedema from the treatment of malignancy (radiation therapy and/or lymph node dissection), affect millions of patients worldwide. Owing to complex and variable anatomy, the lymphatics are not as well understood as other organ systems. Further complicating this is the variability in the description of lymphatic disease processes and their nomenclature in the medical literature. In recent years, medical imaging has begun to facilitate a deeper understanding of the physiology and pathologic processes that involve the lymphatic system. Radiology is playing an important and growing role in the diagnosis and treatment of many lymphatic conditions. The authors describe both normal and common variant lymphatic anatomy. Various imaging modalities including nuclear medicine lymphoscintigraphy, conventional lymphangiography, and MR lymphangiography used in the diagnosis and treatment of lymphatic disorders are highlighted. The authors discuss imaging many of the common and uncommon lymphatic disorders, including primary LMs described by the International Society for the Study of Vascular Anomalies 2018 classification system (microcystic, mixed, and macrocystic LMs; primary lymphedema). Secondary central lymphatic disorders are also detailed, including secondary lymphedema and chylous leaks, as well as lymphatic disorders not otherwise easily classified. The authors aim to provide the reader with an overview of the anatomy, pathology, imaging findings, and treatment of a wide variety of lymphatic conditions. ^©RSNA, 2022.