Objectives: To develop a modified technique for stenting the atrial septum in the treatment of patients with a failing Fontan operation or pulmonary hypertension. Setting: Two tertiary referral centres. Study design: Prospective collaborative clinical study. Patients and methods: A stent was mounted on a standard valvoplasty balloon catheter which was constricted to a predefined diameter by a loop created from a temporary pacing wire. Full balloon inflation created a diabolo shaped stent configuration. The technique was employed in 12 consecutive patients to relieve symptoms of a failing Fontan circulation (n = 6) or severe pulmonary hypertension (n = 6). Results: Ex vivo studies confirmed that a diabolo shaped stent configuration could be achieved using the above technique. Transcatheter stent implantation was successful in all 12 patients. All six Fontan patients showed significant clinical improvement. Right atrial pressure decreased from (mean (SD)) 16.8 (2.5) to 13.7 (1.9) mm Hg (p < 0.05), and arterial oxygen saturation from 92.8 (1.8)% to 82.7 (3.8)% (p < 0.01). Six patients underwent successful stent fenestration for treatment of pulmonary hypertension. All stents were patent and stable at the most recent follow up (mean 1.75 (1.05) years). No early or late stent related complications were encountered. Conclusions: This new technique allows placement of a diabolo shaped stent with a predefined diameter across the atrial septum. The diabolo shape increases stent stability, facilitates recrossing of the stent during future catheter interventions, and ensures medium term stent patency.

Background: Covered stent correction of sinus venosus ASDs (SVASD) is a relatively new technique. Challenges include anchoring a sufficiently long stent in a nonstenotic superior vena cava (SVC) and expanding the stent at the wider SVC‐RA junction without obstructing the anomalous right upper pulmonary vein (RUPV). The 10‐zig covered Cheatham‐platinum (CCP) stent has the advantage of being available in lengths of 5–11 cm and dilatable to 34 mm in diameter.Methods: An international registry reviewed the outcomes of 10‐zig CCP stents in 75 patients aged 11.4–75.9 years (median 45.4) from March 2016. Additional stents were used to anchor the stent in the SVC or close residual shunts in 33/75. An additional stent was placed in 4/5 (80%) with 5/5.5 cm CCPs, 18/29 (62%) with 6 cm CCPs, 5/18 (28%) with 7 cm CCPs, 5/22 (23%) with 7.5/8 cm CCPs and 0/1 with an 11 cm CCP. A “protective” balloon catheter was inflated in the RUPV in 17.Results: Early stent embolization in two patients required surgical removal and defect repair and tamponade was drained in one patient. The CT at 3 months showed occlusion of the RUPV in one patient. Follow up is from 2 months to 5.1 years (median 1.8 years). QP:QS has reduced from 2.5 ± 0.5 to 1.2 ± 0.36 (p < .001) and RVEDVi from 149.1 ± 35.4 to 95.6 ± 21.43 ml/m2 (p < .001).Conclusions: Ten‐zig CCPs of 7–8 cm appear to provide reliable SVASD closure with a low requirement for additional stents. Careful selection of patients and meticulous attention to detail is required to avoid complications.

Increasingly end-organ injury is being demonstrated late after institution of the Fontan circulation, particularly liver fibrosis and cirrhosis. The exact mechanisms for these late phenomena remain largely elusive. Hypothesizing that exercise induces precipitous systemic venous hypertension and insufficient cardiac output for the exercise demand, that is, a possible mechanism for end-organ injury, we sought to demonstrate the dynamic exercise responses in systemic venous perfusion (SVP) and concurrent end-organ perfusion. Ten stable Fontan patients and 9 control subjects underwent incremental cycle ergometry-based cardiopulmonary exercise testing. SVP was monitored in the right upper limb, and regional tissue oxygen saturation was monitored in the brain and kidney using near-infrared spectroscopy. SVP rose profoundly in concert with workload in the Fontan group, described by the regression equation 15.97 + 0.073 watts per mm Hg. In contrast, SVP did not change in healthy controls. Regional renal (p <0.01) and cerebral tissue saturations (p <0.001) were significantly lower and decrease more rapidly in Fontan patients. We conclude that in a stable group of adult patients with Fontan circulation, high-intensity exercise was associated with systemic venous hypertension and reduced systemic oxygen delivery. This physiological substrate has the potential to contribute to end-organ injury.