Successful embolization and long-term follow-up of a rare neonatal diaphragmatic hemangioma.

BACKGROUND: Congenital hemangioma of the diaphragm is an extremely rare disease in childhood.
METHODS: We report a newborn presenting with progressive respiratory distress and massive right hydrothorax due to congenital diaphragmatic hemangioma, requiring sustained ventilation support and chest drainage. The angiography revealed that the giant diaphragmatic hemangioma was supplied by the right internal thoracic, inferior diaphragmatic, and intercostal arteries. The selective embolization of the main feeding vessels was successfully achieved using the Embosphere particulates.
RESULTS: The clinical long-term follow-up demonstrated the resolution of the symptoms, pleural effusion, and nearly complete regression of the hemangioma at 18 months of age.
CONCLUSION: Transcatheter embolization can provide an efficient therapy for symptomatic diaphramatic hemangioma.

Introduction

Congenital hemangiomas of the diaphragm are extremely rare, especially those diagnosed in newborn. We have found only five cases of a primary hemangioma in neonate.[1-5] One was reported by our radiologists with interest in the characteristics of multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI). This is a neonate with right diaphragmatic hemangioma presenting with massive pleural effusion and respiratory distress, which underwent successful embolization. We continuously followed this baby up to 18 months of age and everything was going well. Here, we report this case for a second write-up, as the previous brief imaging report did not include the discussion about the clinical differential diagnosis (from prenatal to postnatal), detail and long-term outcome of the embolization procedure of this special rare case.

Case report

A prenatal ultrasound, performed at 33 weeks of gestation, showed moderate right hydrothorax. And follow-up ultrasound at 34.5 weeks revealed massive right-sided pleural effusion displacing the fetal heart to the left (Figure 1). A cesarean delivery was performed after the failure of fetal thoracocentesis. The birth weight was 2825 g, and both of 1- and 5-min Apgar scores were 9. Shortly after birth, the girl required ventilation support by nasal continuous positive airway pressure (CPAP) and thoracocentesis for significant dyspnea and decreased pulse oxygen saturation (SPO2) around 80%. A right chest tube was placed at 12 days of age, draining a total amount of 677 mL of nonspecific clear and yellow pleural exudates for 15 days. Culture and cytology were negative for microorganism and malignancy.

Figure 1.

Prenatal ultrasound at 34.5 weeks of gestation age shows a large right hydrothorax, reaching 77mm × 49mm × 29mm with the right lung being compressed (open arrow), and the hyperechogenic mass (closed arrow) is recognized in the retrospection of the images.

The thoracic and abdominal ultrasound after birth suggested a mass in the right lower hemithorax, possibly developing from the right diaphragm, with extensive vascularization on color Doppler. Echocardiography showed no cardiac dysfunction or pericardial effusion. MDCT performed at 10 days of life confirmed a contrast-enhancing mass, invading mainly the right diaphragm and extending into the subdiaphragmatic space, indenting the liver. The characteristics of the lesion were consequently confirmed by MRI, which displayed the invasion into the right chest wall and right-sided pericardium as well. A rarely congenital diaphragmatic hemangioma was the suggested diagnosis.

In order to visualize the feeding vessels and possibly carry out embolization, angiography was performed on day 28. The patient was placed in a state of general anesthesia, and a 4-Fr sheath was placed in her right femoral artery by percutaneous puncture. At angiography, the enlarged right internal thoracic and inferior diaphragmatic arteries were demonstrated to be the main feeding vessels of the mass. Inferior vena cavogram showed significant compression at the diaphragm level, leading to the dependent patency of azygos vein draining part of blood to superior vena cava (Figure 2). After super-selective catheterization of each feeding vessel using a 3.0-Fr microcatheter over a micro-guidewire (COOK, USA), Embosphere particulates suspension was slowly injected (particle sizes of 300–500 µm, suspended in 3 mL contrast medium; BioSphere Medical) until complete occlusion was achieved. After initial embolization, repeat angiography revealed that the right 8th, 9th, and 10th intercostal arteries had an increased width and contributed to the vascularity of the lesion. Considering the small amount of blood supplied by the intercostal arteries, embolization was not undertaken. During the procedure, a total of 22 mL of the nonionic low-osmolar contrast medium (iopamidol, 370 mgI/mL; China) was administrated, and the total radiation exposure time and dose were 17.57 min and 209 mGy. The girl was extubated 4 days and discharged completely well 19 days after the procedure. At discharge, her SPO2 was stable at 96%. The thoracic ultrasound showed the pleural effusion was well resolved. Symptoms improved and her weight increased to 3110 g.

Figure 2.

(a) Aortography shows a well-vascularized mass fed by the enlarged right internal thoracic (white arrow) and inferior diaphragmatic arteries (black arrow). (b) Inferior vena cavogram shows significant IVC compression at the diaphragm level (arrow), leading to the dependant patency of azygos vein. (c, d) The selective angiography of the right internal thoracic and inferior diaphragmatic arteries clearly shows a highly vascularized lesion without early filling venous branches. (e) After initial embolization, repeat angiography reveals that the right 8th, 9th, and 10th intercostal arteries have an increased width and contributed slightly to the vascularity of the lesion.

The girl was quite well until 3 months of age; 53 days after embolization, she presented acutely with cough and recurrent tachypnea. Chest radiography showed pneumonia and moderate right hydrothorax. Antibiotics infusion was given for 6 days and a puncture of the pleural effusion was performed and yielded 110 mL of clear and yellow fluid. After pneumonia being resolved, she still presented with mild tachypnea associated with moderate right hydrothorax on chest X-ray film. However, the girl tolerated the feeding well with stable SPO2 around 95%. We decided to take close follow-up on her. At 5 months of age, the child was doing well, demonstrating good catch-up growth without any complications, and ultrasound demonstrated the disappearance of pleural effusion. The ultrasound at 12 months confirmed the tremendous reduction in the size of the hemangioma, and the MRI at 18 months demonstrated nearly complete regression of the mass (Figure 3).

Figure 3.

MRI shows the right diaphragmatic hemangioma. (a) The right diaphragmatic hemangioma shows a pattern of intense hyperintensity on T2-weighted image (arrow). (b) The follow-up MRI examination at 18 months confirms the tremendous regression of the hemangioma (arrow) and the disappearance of pleural effusion.

Given the rarity of the congenital neonatal diaphragmatic hemangioma, the point of our report is to present our experience of diagnosis and interventional embolization approach to obtain more awareness of physicians in their clinic practices. The publication was not only approved by the ethic committee of Children’s Hospital of Fudan University but also consented by the child’s parents.

Discussion

Hemangiomas are the most common vascular tumors in childhood. They usually affect the skin, extremities, and liver, whereas the hemangiomas of the diaphragm are extremely rare. To the best of our knowledge, diaphragmatic hemangioma in the literature to date has only been described in six pediatric cases.[1-4,6,7] In the present case, the diagnosis of a rapid involuting congenital diaphragmatic hemangioma was established mainly by the clinical manifestation and radiographic characteristics of the tumor. Initially, it was defined as an infantile hemangioma (IH) by our radiologists.[5] However, in retrospection of the fetal ultrasound images, we had to admit that the hyperechogenic giant mass adjacent to the right diaphragm was totally missed by our prenatal diagnosis. Therefore, the solitary lesion, which showed early intense enhancement and late diffuse homogeneous hypervascularization on MDCT and MRI, was large and fully formed antenatally, eventually involuted almost completely at 18 months without a significant postnatal proliferative phase. From the clinical view, the diagnosis of a rapid involuting congenital hemangioma (RICH) is preferable to IH in this case, although histological diagnosis was not obtained.

Diaphragmatic hemangioma might be asymptomatic; however, in our case, the baby girl presented with significant respiratory distress due to abundant hydrothorax. In the reported cases of neonatal diaphragmatic hemangiomas, three babies presented with significant ipsilateral hydrothorax, all of which were disclosed by prenatal ultrasonography.[1,3,4] The possible pathophysiological mechanism of the pleural effusion has not been explained by any of the previous authors. We might speculate the obstructed venous return with increased venous pressure due to a space-occupying lesion in the thorax has mainly contributed to this grave situation.[8] Thus, with the current widespread use of obstetric ultrasonography, the diaphragmatic hemangioma might be added as a differential diagnosis for fetal unilateral hydrothorax.

The general principle of management of hemangiomas in children has been fully discussed in our radiologists’ report.[5] In the present case, the baby required sustained ventilation support and chest drainage accompanied with incomplete feeding due to abundant hydrothorax; therefore, rapid removal of the lesion was indicated. After the risks and benefits of possible therapy options for a premature baby were weighed carefully, including long duration treatment of steroids or propranolol, interventional embolization, or surgical excision, we chose the embolization of the major feeding vessels as the initial therapy. In our case, because no evidence of arteriovenous shunt was shown on angiograms, super-selective injection of small size particulate embolic agents was attempted to achieve distal devascularization at a terminal arteriolar level in order to minimize the risk of recanalization. As confirmation of the short-term palliation provided by embolization, the clinical signs of hydrothorax and respiratory distress improved immediately after the procedure. Nevertheless, recurrence of hydrothorax 2 months after embolization indicated the new collaterals might develop. Fortunately, the symptoms were shortly resolved by the subsequent spontaneous regression of the hemangioma to avoid repeated intervention, which were confirmed by follow-up Doppler ultrasound and MRI. In the previous pediatric cases of primary diaphragmatic hemangioma, surgical resection was performed in four patients and interventional embolization in one.[1-3,6,7] In 2001, Curros et al. reported a neonate who was clinically asymptomatic and underwent embolization of the partly regressed diaphragmatic hemangioma at 6 months of life.[1] For the first time, we reported interventional embolization as an initial treatment for large symptomatic diaphragmatic hemangioma in a neonate. Compared with embolization procedure, which allows preservation of the native diaphragmatic tissue and function as well, the surgical excision of the very large hemangioma of the diaphragm in neonate may encounter difficulties in primary closure of the defect produced, probably leading to diaphragmatic dysfunction after operation, particularly in the early postoperative period.[7] The efficacy of the embolization depends on better targeting of the feeding artery and the expertise of the team.