Embryology and Anatomy of Intrapulmonary Shunts

Diffuse large B-cell lymphoma presenting as reversible intrapulmonary arteriovenous shunts with hypoxia, fever and progressive jaundice: a case report and literature review

Background

Intrapulmonary arteriovenous shunts is rare seen in a patient without lung involvement.

Case presentation

This is the first report of reversible intrapulmonary arteriovenous shunts secondary to extrapulmonary lymphoma as one initial symptom. The patient presented as fever of unknown origin and dyspnea, and examinations of infection were negative. Diagnosis of DLBCL was finally confirmed through bone marrow and splenic biopsies. Intrapulmonary arteriovenous shunts were diagnosed through 100% oxygen inhalation test and transthoracic contrast echocardiography (TTCE). After the treatment of lymphoma, his respiratory failure was relieved. We rechecked the 100% oxygen inhalation test and TTCE, which both indicated that his intrapulmonary arteriovenous shunts had resolved.

Conclusions

We speculated the prominent inflammation from active DLBCL was the most possible mechanism associated with the reversible intrapulmonary shunt in this patient. These findings will assist us to better understand the mechanism of intrapulmonary shunts.

Pitfalls of delaying the diagnosis of hereditary haemorrhagic telangiectasia

Hereditary haemorrhagic telangiectasia (HHT; Osler–Weber–Rendu disease) is an autosomal dominant vascular disease characterized by nosebleeds, mucocutaneous telangiectases, visceral arteriovenous malformations (AVM) and a first-degree relative with HHT. Diagnosis is definite if three or four criteria are present. This case report describes a 19-year-old male with incidentally detected polycythaemia and an associated soft-tissue opacity over the left lower lobe on his frontal chest radiogram. He had experienced dyspnoea on exertion since infancy and clubbing at physical examination. Polycythaemia vera, chronic obstructive pulmonary disease, sleep apnoea and cyanotic congenital heart disease were excluded. Chest computed tomography (CT) was initially refused by the patient, but 3 years later he presented with severe epistaxis. Considering the unvarying soft tissue mass and erythrocytosis, an HHT-associated pulmonary AVM (PAVM) was eventually confirmed by chest CT. A pathogenic family-specific ENG c.817-2 A>C mutation was detected in the patient. The large PAVM was successfully treated using AMPLATZER™ vascular plug embolization. A combination of the multisystemic nature of his symptoms, the age-related penetrance of HHT symptoms and insufficient patient compliance delayed the diagnosis of HHT in this current case.

Identification of candidates for PFO closure in the echocardiography laboratory

A patent foramen ovale (PFO) is implicated in several pathologic processes, including that of cryptogenic stroke (cCVA). Recent trials identify "high-risk" PFOs in patients with cCVA as likely to benefit from percutaneous closure. The younger the patient (<60 years old) the more likely a PFO may be attributable to the cCVA. The RoPE Score index helps determine the likelihood that an existing PFO is related to a cCVA. This may help guide the clinician and patient when contemplating percutaneous PFO closure. When evaluating a patient for possible percutaneous closure, one should identify the CVA as a typical ischemic type stroke. In order to "rule-out" other causes of CVA, imaging of the intracranial arteries, cervical, and aortic arch vessels should be performed. Small vessel disease or a lacunar-type infarct should be excluded. To rule out atrial fibrillation, prolonged monitoring should be performed. An index has been developed to determine the probability that a PFO is the causative etiology and calculates the risk of recurrence. This may help guide the clinician and patient in the decision for PFO closure. In addition, one should consider a work-up for a hypercoagulable state. We will obtain an ultrasound of the lower extremities or consider deep pelvic vein thrombosis (prolonged sitting or malignancy). If the closure is to be performed, the Food and Drug Administration (FDA) has approved the Amplatzer PFO Occluder and the GORE Cardioform Septal Occluder for percutaneous closure. These devices are both approved in patients predominately between ages 18 and 60 years with a cCVA due to presumed paradoxical embolism as verified by a neurologist and cardiologist and when other causes of ischemic CVA have been excluded. "High-risk" PFOs appear to achieve the most potential benefit from percutaneous closure.

Pulmonary shunts in severe hepatosplenic schistosomiasis: Diagnosis by contrast echocardiography and their relationship with abdominal ultrasound findings

Background

Schistosomiasis is endemic to several parts of the world. Among the species that affect humans, Schistosoma mansoni is one of the most common causes of illness. In regions where schistosomiasis mansoni is endemic, reinfection is responsible for the emergence of hepatosplenic schistosomiasis (HSS) with portal hypertension in about 10% of infected individuals. Regardless of its etiology, portal hypertension may bring about the formation of arteriovenous fistulas and pulmonary vascular dilation, thus constituting a pulmonary shunt and its presence has been associated with the occurrence of neurological complications. The objective of this study was to identify pulmonary shunt using TTCE in patients with HSS and esophageal varices, and to compare the abdominal ultrasound and endoscopy findings among patients with and without pulmonary shunt.

Methodology/Principal findings

In this case series, a total of 461 patients with schistosomiasis mansoni were prospectively evaluated using abdominal ultrasound and endoscopy and 71 presented with HSS with esophageal varices. Fifty seven patients remained in the final analysis. The mean age of the patients was 55 ± 14 years, and 65% were female. Pulmonary shunts were observed in 19 (33.3%) patients. On comparing the groups with and without pulmonary shunt, no significant differences were observed in relation to the abdominal ultrasound and endoscopic findings. When comparing the two subgroups with pulmonary shunts (grade 1 vs grades 2 and 3), it was observed that the subgroup with shunt grades 2 and 3 presented with a significantly higher frequency of an enlarged splenic vein diameter (>0.9 cm), and an advanced pattern of periportal hepatic fibrosis (P = 0.041 and P = 0.005, respectively). None of the patients with pulmonary shunts had severe neurological complications.

Conclusions/Significance

Our findings suggest that in HSS with esophageal varices the pulmonary shunts may be present in higher grades and that in this condition it was associated with ultrasound findings compatible with advanced HSS.

Among the species of Schistosoma that infect humans Schistosoma mansoni is one of the most common causes of illness. In the areas where schistosomiasis mansoni is endemic, around 10% of infected individuals develop hepatosplenic schistosomiasis (HSS) with portal hypertension. Portal hypertension may promotes an imbalance in the hepatic production of vasoactive substances, which may act on the lungs promoting the formation of arteriovenous fistulas and pulmonary vascular dilation, a condition that is called a pulmonary shunt. When the pulmonary shunt is of higher grades, small thrombus or septic emboli that would normally be filtered through the pulmonary capillaries reach the left heart and the systemic circulation, which can lead to neurological complications. We found pulmonary shunts in patients with HSS and esophageal varices and we also found that patients with higher grades of pulmonary shunts presented with a significantly higher frequency of advanced periportal fibrosis and an enlarged splenic vein diameter. No neurological complications were observed. Our findings suggest that pulmonary shunts may be present in patients with HSS and esophageal varices. The abdominal ultrasound findings compatible with advanced HSS could be used as screening to investigate pulmonary shunt.

Saline Contrast Echocardiography in the Era of Multimodality Imaging--Importance of "Bubbling It Right"

Saline contrast echocardiography is an established imaging modality. Logical interpretation of a carefully performed study is vital to realize its diagnostic potential. In this review, we discuss utility of saline contrast echocardiography in evaluation of various pathologies within and outside the heart other than a patent foramen ovale.