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

Abstract

Background: Potts shunt has been suggested as an effective palliative therapy for patients with pulmonary artery hypertension (PAH) not associated with congenital heart disease.

Materials and methods: This is a prospective single-center study performed to assess outcomes of Potts shunt in patients with PAH who are in functional class III or IV.

Results: 52 patients in functional class III/IV with pulmonary arterial hypertension without significant intra or extracardiac shunt on maximal medical therapy were evaluated and counseled for undergoing Potts shunt/patent ductus arteriosus (PDA) stenting. 16/52 patients (13 females) consented for the procedure; 14 patients underwent surgical creation of Potts, and 2 underwent transcatheter stenting of PDA, which physiologically acted like a Potts shunt. Standard medical therapy was continued in patients who did not consent for the procedure. 12/16 patients survived the procedure. Patients who did not survive the procedure were older, with severe right ventricular systolic dysfunction, and functional class IV. Patients who survived the procedure were followed up in the pulmonary hypertension clinic. The Median follow-up was 17 months (1-40 months). 11/13 patients discharged after the operation showed sustained clinical, echocardiographic, and biochemical improvement, which reduced need for pulmonary vasodilator therapy in 10/13 patients. There was one death in the follow-up period 16 months post-surgery due to lower respiratory tract infection.

Conclusion: Potts shunt is feasible in patients with PAH without significant intra or extracardiac shunts. It can be done safely with an acceptable success rate. Patient selection, preoperative stabilization, and meticulous postoperative management are essential. It should be performed at the earliest sign of clinical, echocardiographic, or laboratory deterioation for optimal outcomes. Long-term follow-up is required to see a sustained improvement in functional class and the need for a lung transplant in the future.

Keywords: Bridge to transplant; Reverse Potts shunt; Right ventricular dysfunction.

Fig. 1

Change in World Heat organization functional class in patients pre Potts shunt and at last follow up. All except two patients demonstrated improvement in functional class by at least 1 grade after the shunt.

Fig. 2

Improvement in echocardiographic and laboratory parameters pre and post shunt. A. N terminal pro Brain natriuretic peptide (NT pro BNP) decreased by medina of 63% (+18,-82%). B. Longitudinal right ventricular function measured as tricuspid annular peak systolic excursion increased by median of 70% (−14, 100%). B. Right ventricular function measured as right ventricular fractional area change (RVFAC) increased by median of 88% (−25,167%).

Fig. 3

Box and Whisker plot comparing the echocardiographic features of group 1 (benefited from Potts shunt) and group 2 (Did not benefit from the Potts shunt). Patients with group 1 had significantly better tricuspid annular peak systolic excursion (TAPSE) (Figure A), p value < 0.001 and B shows the difference in Right ventricular fractional area change (RVFAC), (figure B) p value = 0.02.

Fig. 4

Box and Whisker plot comparing the echocardiographic features of group 1 (benefited from Potts shunt) and group 2 (Did not benefit from the Potts shunt). Patients with group 1 had significantly higher pulmonary artery acceleration time (PAAT) (Figure A), p value = 0.02 and B shows the difference in left ventricular eccentricity index (figure B) p value = 0.04.

Fig. 5

Box and Whisker plot comparing the cardiac catheterization features of group 1 (benefited from Potts shunt) and group 2 (Did not benefit from the Potts shunt). Patients with group 1 had significantly higher pulmonary vascular resistance indexed to body surface area (PVRI) (Figure A), p value = 0.01 and higher right atrial pressure (RAP) (figure B) p value = 0.003.

Fig. 6

Box and Whisker plot comparing the levels of N terminal Pro brain natriuretic peptide (NT pro BNP) of group 1 (benefited from Potts shunt) and group 2 (Did not benefit from the Potts shunt). Patients in group 2 had significantly higher NT pro BNP levels as compared to those in group 1 (p value < 0.001).

Fig. 7

Kaplan Meir survival graph demonstrating survival of 70% at 40 months after the Potts shunt surgery.

Fig. 8

Kaplan Meir survival graph comparing survival in patients who were older (Age > 16 years) (Figure A), severe right ventricular systolic dysfunction as measures by tricuspid annular peak systolic excursion (TAPSE) less than 13 mm (figure B), right atrial pressure (RAP) > 8 mm Hg (Figure C) and cardiac index lesser than 2.5 l/min/m2 (Figure D). Comparison between the groups was done using Log rank test.