Introduction
Pulmonary arterial hypertension is a severe, progressive disease causing increased right ventricular pressure, right heart failure, and high mortality despite advances in medical treatments. Reference Hansmann, Koestenberger and Alastalo1,Reference Moledina, Hislop, Foster, Schulze-Neick and Haworth2 Palliative options, such as the reverse Potts shunt and balloon atrial septostomy, are used in cases of severe, uncontrolled pulmonary arterial hypertension as a bridge to transplantation. Reference Hansmann, Koestenberger and Alastalo1,Reference Hansmann3,Reference Baruteau, Serraf and Lévy4 Genetic predisposition is now widely recognised in certain forms of pulmonary arterial hypertension. Among these genetic factors, extremely rare cases of polycythemia and pulmonary arterial hypertension have been reported, caused by homozygous or compound heterozygous mutations in the Von Hippel–Lindau tumour suppressor gene. Reference Chomette, Migeotte and Dewachter5,Reference Sarangi, Lanikova and Kapralova6
In this paper, we report the first case of the interventional creation of a reverse Potts shunt by stenting a closed ductus arteriosus (endogenous Potts shunt) in a patient with severe pulmonary arterial hypertension associated with Von Hippel-Lindau disease.
Case report
A four-year-old patient, weighing 15 kg, was referred to our institute with a diagnosis of pulmonary arterial hypertension and a patent ductus arteriosus previously made at a peripheral hospital. At two and a half years of age, a temporary balloon occlusion test was performed during catheter angiography to assess the haemodynamic impact and feasibility of patent ductus arteriosus closure. The procedure revealed suprasystemic pulmonary arterial hypertension, and the vasoreactivity test with inhaled iloprost yielded negative results. Six months after the procedure, the patient’s symptoms progressively worsened, leading to right heart failure, two admissions to the paediatric ICU, and the initiation of a third pulmonary arterial hypertension therapy. Subsequently, the patient was referred to our hospital for consideration of lung transplantation. At the time, the patient was receiving treatment with iloprost, sildenafil, bosentan, and furosemide.
At our hospital, the physical examination revealed tachycardia and tachypnoea. There was hepatomegaly, with the liver palpable 8 cm below the ribs. The patient was evaluated as functional class 3–4. Oxygen saturation was 96% in the upper right extremity and 94% in the lower right extremity. Transthoracic echocardiography revealed right ventricle dilatation, bowing of the interventricular septum to the left, and minimal pericardial effusion (Figure 1). Suprasystemic pulmonary arterial hypertension with an right ventricle systolic pressure of 95 mmHg was identified through the tricuspid regurgitation jet. The findings also included signs of right ventricular systolic and diastolic dysfunction, moderate-severe tricuspid regurgitation, a decreased tricuspid annular plane systolic excursion of 8 mm, a tricuspid annular E/A wave ratio of 0.8, and an increased right ventricle end-diastolic diameter to left ventricular end-diastolic diameter ratio of 35/19 mm.
Transthoracic echocardiogram showing right atrium-ventricle dilatation, bowing of the interventricular septum to the left, moderate–severe tricuspid regurgitation and minimal pericardial effusion.
Due to the worsening of the patient’s symptoms following catheter angiography, the inability to visualise the ductus arteriosus on transthoracic echocardiography, and the absence of a significant difference in oxygen saturation between the upper and lower extremities, computed tomography angiography was performed to confirm the presence of the ductus arteriosus. This revealed the presence of a ductal ampulla but showed no patency of the ductus arteriosus.
Catheter angiography was performed to evaluate ductus arteriosus patency and explore the feasibility of creating a reverse Potts shunt or performing a balloon atrial septostomy. After obtaining informed consent, the procedure was conducted under general anaesthesia and confirmed suprasystemic pulmonary arterial hypertension with a pulmonary artery pressure of 95/73 (mean: 83) mmHg, an aortic pressure of 47/27 (mean: 32) mmHg, a pulmonary artery wedge pressure of 10 mmHg, a mean right atrium pressure of 31 mmHg, a pulmonary-to-systemic blood flow ratio (Qp/Qs) of 0.97, and an estimated indexed pulmonary vascular resistance of 12.5 WU · m2.
Initial aortic arch angiography showed no flow through the ductus arteriosus. Given the patient’s elevated right atrial pressure, balloon atrial septostomy was deemed inappropriate, and ductus recanalisation was considered the optimal palliative option. Repeated angiography using 4F Judkins right 4 catheters positioned in both the ductal ampulla and the pulmonary artery revealed no flow through the ductus arteriosus in either injection (Figure 2A, 2B). Attempts to cross theductus arteriosuswith multiple coronary guidewires were also unsuccessful. Prostaglandin (125 mcg) was administered to the ductal ampulla, revealing minimal contrast shunting, prompting a repeat bolus. After multiple attempts, a chronic total occlusion guidewire successfully traversed the closed ductus arteriosus into the pulmonary artery and right ventricle (Figure 2C). The ductus arteriosus was dilated with 3.5 x 12 mm and 5 x 20 mm non-compliant coronary balloon catheters (Apollo™ NC PTCA Balloon Catheter) (Figure 2D). With the support of a 6F long sheath, an AdvantaTM V12 covered stent (6 mm x 22 mm) was placed and inflated across the ductus arteriosus, with the subsequent contrast injection confirming successful recanalisation and stenting (Figure 2E, 2F, Supplementary Video 1).
( a ),( b ); Aortic arch angiography showing no flow through the ductus arteriosus, ( c ); a chronic total occlusion guidewire traversing the closed ductus arteriosus into the pulmonary artery and RV, ( d ); the ductus arteriosus id dilating with non-compliant coronary balloon catheters, ( e ), ( f ); an advanta™ V12 covered stent (6 mm x 22 mm) is being positioned across the ductus arteriosus with the support of a 6F long sheath.
Following the procedure, the PA pressure was 107/52 (mean: 78) mmHg, and the ascending aortic pressure was 87/54 (mean: 68) mmHg. The Qp/Qs was calculated to be 0.40, along with an estimated PVRi of 9.6 WU · m2. The procedure was completed without complications.
On the first post-procedure day, echocardiography showed a well-tolerated ductal stent with unrestricted right-to-left flow. The patient’s symptoms and functional class improved to class 3. TAPSE increased to 12 mm, and the tricuspid annular E/A wave ratio normalised to 1.2. The right ventricle end-diastolic diameter and the right ventricle/left ventricleratio decreased after the procedure to 33 mm and 33/22, respectively, indicating the pressure unloading of the RV and the reduced end-systolic compression of the left ventricle. Oxygen saturation was measured at 96% in the upper right extremity and at 75% in the lower right extremity.
The patient was discharged on the third day after the procedure with a regimen of pulmonary vasodilators (sildenafil, bosentan, and iloprost) to manage pulmonary hypertension and antiplatelet therapy (aspirin, clopidogrel) to prevent stent-related thrombosis. The follow-up strategy focuses on ensuring the long-term success of ductal stenting. Regular echocardiography will monitor stent patency and right heart function. Complication monitoring includes stent restenosis, thrombosis, or migration, with families educated on home oxygen saturation monitoring (including both upper and lower extremities) to detect early signs of deterioration. In case of stent closure, balloon angioplasty will be considered for reopening before complete occlusion occurs. While the patient has shown improvement, lung transplantation remains a potential option for refractory pulmonary hypertension or progressive right heart failure guided by a multidisciplinary team approach.
Discussion
This is the first documented case of the creation of a reverse Potts shunt by stenting a closed ductus arteriosus (endogenous Potts shunt) in a patient with severe pulmonary arterial hypertension associated with Von Hippel-Lindau disease. This case highlights the potential of advanced interventional techniques for managing severe pulmonary arterial hypertension, offering promising prospects for improved outcomes in similarly challenging cases.
The five-year survival rate for patients with pulmonary arterial hypertension under medical treatment without transplantation is less than 60%, Reference Moledina, Hislop, Foster, Schulze-Neick and Haworth2 highlighting the necessity of exploring alternative medical or palliative options for children whose conditions worsen despite receiving maximal medical therapy. Interventional procedures, such as the creation of a reverse Potts shunt or performing a balloon atrial septostomy, present promising alternatives for palliation or as a bridge to transplantation for patients whose condition worsens while on medical therapy or who experience right heart failure. Reference Hansmann, Koestenberger and Alastalo1,Reference Moledina, Hislop, Foster, Schulze-Neick and Haworth2 These procedures decompress the right atrium (balloon atrial septostomy) or the right ventricle (reverse Potts shunt), resulting in a haemodynamic situation similar to the physiology of patients with Eisenmenger syndrome. However, only the reverse Potts shunt can prevent right ventricle failure in the mid-to-long term in contrast to balloon atrial septostomy. Compared to atrial septostomy, the reverse Potts shunt preserves oxygen saturation in the brain and coronary arteries, is independent of right atrial pressure, reduces right ventricle afterload, provides right ventricle systolic decompression that enhances right ventricle-to-pulmonary artery coupling, improves septal geometry, and enhances left ventricular performance. Reference Hansmann, Koestenberger and Alastalo1–Reference Baruteau, Serraf and Lévy4 This procedure maintains sufficient cardiac output but leads to hypoxaemia in the lower half of the body. Reference Boudjemline, Patel and Malekzadeh-Milani7,Reference Latus, Apitz and Moysich8
Reverse Potts shunt circulation is achieved surgically or via interventional techniques that connect the descending aorta and the pulmonary artery. Interventional Potts shunt techniques involving the creation of a direct connection between the aorta and the pulmonary artery or stenting the ductus arteriosus, offer a less invasive and potentially safer alternative to surgical Potts shunts for the palliative treatment of pulmonary arterial hypertension. Additionally, interventional patent ductus arteriosus stenting offers the advantage of allowing the stented patent ductus arteriosus to be closed when pulmonary artery pressure decreases to a sub-systemic level. Reference Sarangi, Lanikova and Kapralova6–Reference Latus, Apitz and Moysich8 While an interventional endogenous reverse Potts shunt offers a long-term and permanent solution by maintaining sufficient cardiac output, the procedure presents technical challenges and potential complications, including adverse outcomes, such as hypoxaemia in the lower half of the body. Reference Boudjemline, Patel and Malekzadeh-Milani7,Reference Latus, Apitz and Moysich8 It is crucial to recognise these possible complications and prepare to manage them effectively. During the crossing of the arterial duct, irritation to the ductal intima may result in sudden spasms and the total occlusion of the duct. Reference Boudjemline, Patel and Malekzadeh-Milani7–Reference Alwi10 We hypothesise that our patient’s ductus arteriosus that was previously patent may have closed due to ductal irritation caused by the balloon occlusion test during the initial catheterisation. However, the presence of endothelial dysfunction in patients with Von Hippel-Lindau disease may enhance this ductal intimal sensitivity and, together with the irritation caused by the balloon, potentially predispose the previously patent ductus to spontaneous closure. Reference de Rojas-P, Albiñana and Taranets11 Another potential complication is the tearing or dissection of the ductal wall by the wire or catheter. Furthermore, stent embolisation and migration may occur during deployment. Reference Alwi10 In this patient, a covered stent was chosen to minimise the risks associated with endothelial dysfunction linked to Von Hippel-Lindau disease and the potential for fragile vessel walls, aiming to prevent leakage or rupture while ensuring procedural safety. Reference de Rojas-P, Albiñana and Taranets11 However, the decision to use a covered stent in other patients with Von Hippel-Lindau disease should be individualised, based on their vascular anatomy, procedural risks, and clinical needs
Transcatheter reverse Potts shunt formation presents significant technical challenges, especially when the ductus arteriosus is occluded. The primary difficulty lies in advancing a guidewire across the ductus arteriosus without any prograde flow. Our patient’s ductus arteriosus was completely closed at the time of the procedure. We successfully re-canalised it using a combination of local prostaglandin infusion and the manipulation of a chronic occlusion guidewire before stent implantation.Reference Santoro, Gaio and Palladino12,Reference Ahmed, LaCroix, Bader Ishqair, Shivaram and Das13 A ductal ampulla or notch can significantly improve the likelihood of a successful procedure. Reference Ahmed, LaCroix, Bader Ishqair, Shivaram and Das13 Clinicians have occasionally used local prostaglandin therapy during the re-canalisation of the ductus arteriosus. Reference Santoro, Gaio and Palladino12 Local prostaglandins can induce vasodilation and enhance blood flow at the ductus site, potentially increasing the success rate of the re-canalisation procedure.
Balloon atrial septostomy is a straightforward procedure with immediate effects but carries risks such as embolisation, inadequate oxygenation, atrial arrhythmias, and procedural complications, e.g., perforation of the atrial septum. While balloon atrial septostomy can improve symptoms in severe pulmonary arterial hypertension, the size of the defect remains crucial. An excessively large shunt can cause life-threatening desaturation, while a small shunt may close spontaneously, requiring repeated procedures . Reference Sarangi, Lanikova and Kapralova6,Reference Al Maluli, DeStephan, Alvarez and Sandoval14 Due to our patient’s right atrial pressure exceeding 20 mmHg, balloon atrial septostomy was deemed inappropriate. Because elevated right atrial pressure, especially with an excessively large defect, can increase the likelihood of a right-to-left shunt that bypasses the lungs, leading to systemic desaturation, worsening hypoxaemia, and organ dysfunction. Reference Al Maluli, DeStephan, Alvarez and Sandoval14
In patients with suprasystemic pulmonary arterial hypertension, the presence of a right-to-left shunt can make the ductus challenging to visualise on echocardiography. Therefore, the difference in oxygen saturation between the upper and lower extremities can provide information about the patency of the ductus. Early detection of a decreasing difference in oxygen saturation between the upper and lower extremities can facilitate stenting before the patent ductus arteriosus completely closes. Since ductus recanalisation is not always achievable and surgical Potts shunts can be risky for this patient group, monitoring the oxygen saturation difference between the upper and lower extremities is crucial in guiding treatment, Reference Sarangi, Lanikova and Kapralova6 as demonstrated in this case.
In conclusion, creating a palliative transcatheter Potts shunt by recanalizing and stenting a closed ductus arteriosus offers a novel approach for severely ill patients with suprasystemic pulmonary arterial hypertension. This case also demonstrates that late ductus recanalisation is feasible in paediatric patients beyond infancy. Additionally, local prostaglandin could be a valuable strategy for successfully recanalizing a closed ductus arteriosus.
Supplementary material
The supplementary material for this article can be found at https://doi.org/10.1017/S1047951125001374.
