Ray of hope for end stage pulmonary hypertension: Pott's shunt
Recent research published in the Indian Heart Journal has suggested that Potts shunt is feasible in patients with PAH without significant intra or extracardiac shunts. It can be done safely with an acceptable success rate.
Pulmonary arterial hypertension (PAH) is a progressive disease with grim prognosis and a 5-year survival ranging from 57 to 75%. Prostacyclin analogs are known to reduce mortality but are still unavailable or not unaffordable to the general Indian population. Until recently, lung or heart-lung transplant was thought to be the only surgical option available, which is also cost-prohibitive with limited availability and guarded long term outcomes.
Creating Potts shunt is considered as an alternative option in both adult and pediatric patients with PAH who show symptomatic deterioration on maximal medical therapy. This innovative therapy postulates that by creating an unrestrictive communication between the descending aorta and left pulmonary artery, there would be a reduction in the right ventricular afterload which will cause conversion of an idiopathic PAH physiology to Eisenmenger physiology with better functional capacity and survival.
Bhobhate et al from Kokilaben Dhirubai Ambani Hospital and Research Center, Maharashtra, conducted a prospective single-center study performed to assess outcomes of Potts shunt in patients with PAH who are in functional class III or IV.
52 patients in functional class III/IV with PAH on maximal medical therapy were evaluated and counseled for undergoing Potts shunt/patent ductus arteriosus (PDA) stenting. 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 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. 11 patients discharged after the operation showed sustained clinical, echocardiographic, and biochemical improvement, which reduced need for pulmonary vasodilator therapy in 10 out of 13 patients. There was one death in the follow-up period 16 months post-surgery due to lower respiratory tract infection.
"Creation of a non-restrictive communication between the left pulmonary artery and the descending aorta (Potts shunt) has shown significant mortality and morbidity benefits in patients with PAH. 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", observed the authors.
"Preoperative stabilization with milrinone, IV sildenafil, and nitric oxide is essential for successful postoperative outcomes. This is especially true in the Indian scenario where prostacyclin analogues are not readily available", added the authors.
"Potts shunt/PDA stenting is feasible in patients with PAH; it can be done safely with an acceptable success rate. Patient selection, preoperative stabilization, and meticulous intra and postoperative management are essential. For optimal outcomes, it should be performed at the earliest sign of clinical, echocardiographic, or laboratory deterioration before severe right ventricular dysfunction sets in. Long-term follow-up is required to ascertain sustainable improvement in functional class and the need for a lung transplant", concluded the authors in this article.
Source: Indian Heart Journal: Prashant Bobhate, Smruti Ranjan Mohanty, Kamlesh Tailor, Shankar Kadam, Tanuja Karande, Keyoor Bhavsar, Hari Bipin Katanna, Suresh Rao, Snehal Kulkarni, Potts shunt as an effective palliation for patients with end stage pulmonary arterial hypertension, Indian Heart Journal, 2021, https://doi.org/10.1016/j.ihj.2021.01.007