Platypnea-orthodeoxia syndrome after open prostatectomy and cystolithotomy: Coincidence or unknown pathophysiology?

Abstract

A few cases of platypnea-orthodeoxia syndrome have been described in the literature, some of them after thoracic or upper abdominal surgeries. In most cases, hypoxemia in the upright or sitting position, which is the main clinical symptom for this uncommon diagnosis, is usually related to a dynamic right to left cardiac shunt induced by anatomical changes in the relative position between the inferior vena cava and the atria in the presence of a patent foramen ovale. In this case report, we describe a situation in which platypnea-orthodeoxia syndrome developed acutely before surgery but that became severely exacerbated after an open urologic surgery without a clear acute anatomical change that could be responsible for triggering the syndrome. This case might suggest that the pathophysiology of acute platypnea-orthodeoxia syndrome is not completely elucidated and that other possible triggers for acute clinical manifestation in addition to acute anatomical thoracic changes must be explored.

Percutaneous closure of patent foramen ovale for treatment of hypoxemia: A case series and physiology review

“…However, this process can also be facilitated in the setting of normal right atrial pressure when an anatomical distortion alters the usual interface between the interatrial septum and either vena caval flow or, if present, a tricuspid regurgitant jet, resulting in preferential streaming of blood directed at and through an existing PFO. [4][5][6][7][8][9] In particular, horizontal displacement of the interatrial septum is more likely to result in the PFO being aligned with inferior vena cava (IVC) flow. 14 Predisposing variants include the presence of a prominent Eustachian valve or an atrial septal aneurysm (ASA).…”

“…Both transient and chronic physiologic conditions that raise right‐sided cardiac pressures can reverse this gradient, promoting RTLS with resultant hypoxemia. Intracardiac RTLS across a PFO also occurs in the setting of normal right‐sided cardiac pressures when congenital or acquired distortions of the cardiopulmonary anatomy alter the geometric relationship between the interatrial septum and vena cava blood flow, resulting in preferential streaming of deoxygenated venous blood across the PFO 4–9 . The same process may also ensure from a tricuspid regurgitant jet.…”

“…Intracardiac RTLS across a PFO also occurs in the setting of normal right-sided cardiac pressures when congenital or acquired distortions of the cardiopulmonary anatomy alter the geometric relationship between the interatrial septum and vena cava blood flow, resulting in preferential streaming of deoxygenated venous blood across the PFO. [4][5][6][7][8][9] The same process may also ensure from a tricuspid regurgitant jet. This physiology is often accentuated in the upright position, leading to presentation with platypnea-orthodeoxia syndrome.…”