Potts Shunt to Be Preferred Above Atrial Septostomy in Pediatric Pulmonary Arterial Hypertension Patients: A Modeling Study

Abstract

Aims: To quantitatively evaluate the basic pathophysiological process involved in the creation of Eisenmenger syndrome in pediatric pulmonary arterial hypertension (PAH) patients by either atrial septostomy (AS) or Potts shunt (PS) as well as to predict the effects of AS or PS in future PAH patients.Methods: The multi-scale lumped parameter CircAdapt model of the cardiovascular system was used to investigate the effects of AS and PS on cardiovascular hemodynamics and mechanics, as well as on oxygen saturation in moderate to severe PAH. The reference simulation, with cardiac output set to 2.1 l/min and mean systemic pressure to 61 mmHg, was used to create a compensated moderate PAH simulation with mPAP 50 mmHg. Thereupon we created a range of decompensated PAH simulations in which mPAP was stepwise increased from 50 to 80 mmHg. Then we simulated for each level of mPAP the acute effects of either PS or AS with connection diameters ranging between 0–16 mm.Results: For any mPAP level, the effect on shunt flow size is much larger for the PS than for AS. Whereas right ventricular pump work in PS is mainly dependent on mPAP, in AS it depends on both mPAP and the size of the defect. The effects on total cardiac pump work were similar for PS and AS. As expected, PS resulted in a drastic decrease of lower body oxygen saturation, whereas in AS both the upper and lower body oxygen saturation decreased, though not as drastically as in PS.Conclusion: Our simulations support the opinion that a PS can transfer suprasystemic PAH to an Eisenmenger physiology associated with a right-to-left shunt at the arterial level. Contrary to the current opinion that PS in PAH will decompress and unload the right ventricle, we show that while a PS does lead to a decrease in mPAP toward mean systemic arterial pressure, it does not unload the right ventricle because it mainly diverts flow from the pulmonary arterial system toward the lower body systemic arteries.

Potts shunt as an effective palliation for patients with end stage pulmonary arterial hypertension

“… 3 , 12 Unlike atrial septostomy, Potts shunt does not create arterial desaturation in the upper part of the body including cerebral and coronary circulation and the shunt remains open throughout the cardiac cycle. 18 Improvement in functional class, reduction in need for PAH specific medications and improvement in right ventricular function has been demonstrated after creation of the Potts shunt. 19 , 20 , 21 …”

Successful Management of an Infant with Atypical Presentation of Alveolar Capillary Dysplasia with Misalignment of the Pulmonary Veins

“…[7][8][9] Right-to-left shunting at the atrial level, on the contrary, may cause intolerable preductal arterial hypoxemia and should be avoided. 10 Pulmonary vasodilators, such as iNO and riociguat, can be used for long-term medical treatment. Breathing NO via nasal canula was feasible over a period of more than 2 years, without detectable side effects.…”

A novel unidirectional-valved shunt approach for end-stage pulmonary arterial hypertension: Early experience in adolescents and adults

“…Preserved RV function is considered a prerequisite for the reversed Potts shunt because of concerns that a compromised RV is unlikely to improve by reducing the systolic PAP from suprasystemic to systemic pressure, an opinion supported by a simulation study suggesting that RV afterload changes little after Potts shunt, 20 hence raising concerns that the compromised RV will suffer further from exposure to systemic pressures from the aortic runoff with a bidirectional shunt. This will result in pressure and volume shifts into the pulmonary circulation during periods when the systemic pressure is greater than PAP, resulting in a greater resting mean PAP.…”