Investigation of patent foramen ovale as a mechanism for brain metastasis in patients without prior lung involvement.

PURPOSE: The mechanisms of brain metastasis are incompletely understood. Circulating tumor cells travel to the right heart and through the pulmonary circulation, where they may become lung metastases, and can circulate further to the left heart and brain. In patients who develop brain metastases without lung involvement, we hypothesized that cancer cells may travel directly from the right atrium to left atrium via a patent foramen ovale (PFO), akin to paradoxical embolism. If the prevalence of PFO is greater in these individuals compared to the general population (20-30%), PFO may play a role in brain metastasis, and prophylactic closure may provide benefit. Accordingly, we investigated the prevalence of PFO in patients with brain metastases without prior lung involvement. METHODS: We prospectively identified patients with brain metastases from a non-lung primary cancer with no preceding or concurrent lung involvement. Nine eligible participants underwent a transcranial Doppler study with intravenous agitated saline to assess for PFO. RESULTS: Among nine participants, primary cancers were breast (n = 6), upper gastrointestinal (n = 2), and thyroid (n = 1). A positive bubble study was identified in 2/9 (22.2%) participants: one female with breast cancer and one male with duodenal adenocarcinoma. No participants developed lung metastases on subsequent chest imaging. CONCLUSION: In this prospective pilot study, we found a similar prevalence of PFO in patients who developed brain metastases without preceding lung involvement compared to estimates for the general population. Through a larger study is needed, the development of brain metastases in these individuals may primarily reflect tumor-specific biological factors diecting metastasis organotropism.

Experience with Percutaneous Transcatheter Closure of Interatrial Communications at the Cardiovascular Center of Puerto Rico and the Caribbean.

OBJECTIVE: The annual rate of percutaneous transcatheter closure of atrial septal defects (ASDs) and patent foramen ovales (PFO) has markedly increased in the United States over the past decade. This technique has been used at the Cardiovascular Center for Puerto Rico and the Caribbean since 2005. We report on the clinical characteristics and the immediate and short-term follow-up of adult patients who underwent this procedure at this center from 2008 to 2012. METHODS: One hundred and two consecutive medical records of adult Hispanic patients who underwent this procedure at our center from 2008 to 2012 were identified. A retrospective analysis of the clinical characteristics and the immediate and short-term clinical and echocardiographic follow-up of those patients was performed. RESULTS: The study population comprised 70 women and 32 men, with a mean age of 51 years (age range: 19 to 80 years). Of those, 43 (42%) underwent ASD closure and 60 (59%), closure of a PFO. A 99% procedural success rate was achieved. There were only 3 procedural complications, including the failure of the initial implantation of 1 device, which required the endovascular removal of that device and the implantation of another, a hematoma at the vascular access site, and 1 brief episode of atrial fibrillation. CONCLUSION: Based on our review of the available records, we were able to determine that the percutaneous transcatheter closure of interatrial communications proved to be, at our institution, a safe procedure with a high success rate and a low incidence of in-hospital complications. To our knowledge, this is the first report on the utilization of this interventional procedure in Puerto Rico.

Importance of adequately performed Valsalva maneuver to detect patent foramen ovale during transesophageal echocardiography.

BACKGROUND: Transesophageal echocardiography (TEE) plays an important role in evaluating cardioembolic sources of emboli. The identification of a patent foramen ovale (PFO) is reportedly improved with TEE compared with transthoracic echocardiography (TTE), but the Valsalva maneuver during TEE may be difficult or suboptimal. The aim of this study was to assess the efficacy of the Valsalva maneuver for PFO diagnosis using TEE compared with TTE by evaluating patients with ischemic stroke referred for echocardiography. METHODS: Only patients able to perform the Valsalva maneuver during TTE were included; efficacy was defined by a 20 cm/sec decrease in transmitral E velocity. A PFO was judged present when microbubbles of agitated intravenous saline were seen in the left chambers within three cycles after right atrial opacification. RESULTS: Of 108 patients (mean age, 55 ± 15 years; 61 men), 48 (44%) were judged to have PFOs by TEE and/or TTE. In 36 patients (33% of the total, 75% of those with PFOs), microbubbles were observed both by TEE and TTE, in seven patients only during TTE, and in five patients only during TEE. In patients able to satisfactorily perform the Valsalva maneuver during TEE, 22 PFOs were found, and two shunts (9%) were missed, whereas in patients unable to perform this maneuver, 26 PFOs were observed, with five shunts missed (19%) (P < .05). When a PFO was missed by TTE, either the echocardiographic window was suboptimal or the shunt was small. CONCLUSIONS: An adequate Valsalva maneuver is crucial for diagnosis of PFO; most patients with stroke may be screened using TTE with contrast and the Valsalva maneuver, with TEE indicated in case of suboptimal transthoracic images.