Das D, Sarkar T, Das S, Malladi V, Sharma MK, Gajpal S, Chattopadhyay A. Prospective observational study comparing the outcomes of fenestrated and non-fenestrated extracardiac Fontan procedure. Cardiol Young. 2026;36:663-667. doi:10.1017/S1047951126112153.
PubMed: https://pubmed.ncbi.nlm.nih.gov/41969224/
Take-Home Points
- In this prospective single-center study of 40 low-risk Fontan patients, routine fenestration did not significantly improve most early postoperative outcomes.
- Total pleural drainage, duration of mechanical ventilation, ICU stay, and overall hospital stay were similar between fenestrated and non-fenestrated Fontan groups.
- Chest tube duration was numerically lower in the fenestrated cohort (8.1 vs 10.2 days) but did not achieve statistical significance.
- Discharge oxygen saturation was significantly lower in fenestrated patients (88.9% vs 93.3%; p=0.0072), reflecting the expected right-to-left shunt physiology.
- No deaths occurred in either group.
- These findings suggest that routine fenestration may offer limited perioperative benefit in carefully selected lower-risk extracardiac Fontan patients.
Commentary from Dr. Varun Aggarwal (Wilmington, DE, USA), editor-in-chief of Congenital Heart Disease Journal Watch:
Few technical modifications in Fontan surgery have generated as much debate as fenestration. More than three decades after Bridges and colleagues popularized the concept, the congenital heart community remains divided regarding when fenestration should be used, who benefits most, and whether routine application is justified. The current study from Das and colleagues revisits this enduring question in a contemporary extracardiac Fontan cohort and arrives at a conclusion that many experienced Fontan programs may find familiar: in lower-risk patients, routine fenestration may not meaningfully improve early postoperative outcomes.
The physiologic rationale for fenestration is compelling. The Fontan circulation is inherently dependent on passive venous return through the pulmonary vascular bed without a sub pulmonary ventricle. In the immediate postoperative period, elevated systemic venous pressures and reduced ventricular preload can create a precarious hemodynamic balance. A fenestration functions as a controlled pop-off valve, decompressing the Fontan circuit and augmenting preload at the expense of mild systemic desaturation. Theoretical benefits include lower venous pressures, improved cardiac output, reduced pleural effusions, shorter chest tube duration, and earlier discharge. These considerations have traditionally led many surgeons to selectively fenestrate patients perceived to be at elevated risk.
The challenge, however, has always been determining whether these theoretical advantages translate into clinically meaningful outcomes in lower-risk patients.
In this prospective observational study, the authors compared 20 fenestrated and 20 non-fenestrated extracardiac Fontan patients. Importantly, high-risk patients with elevated pulmonary vascular resistance, increased transpulmonary gradients, branch pulmonary artery distortion, or primary Fontan procedures were excluded. In essence, this was a study of relatively favorable Fontan candidates.
Within that context, the principal findings are noteworthy. Fenestration failed to significantly reduce mechanical ventilation duration, ICU stay, hospital stay, or overall pleural drainage. Although chest tube duration was shorter in the fenestrated group, the difference did not achieve statistical significance. Perhaps most importantly, there was no signal suggesting a clinically transformative early benefit from routine fenestration.
The observation that fenestrated patients were discharged with lower oxygen saturations is neither surprising nor trivial. Fontan clinicians often become accustomed to describing a fenestration as a relatively benign intervention, yet it intentionally creates chronic cyanosis. In the current cohort, discharge saturations averaged approximately 89% in fenestrated patients compared with 93% in non-fenestrated patients. While this difference may appear modest, it reflects the fundamental tradeoff inherent in fenestration strategy: improved decompression in exchange for systemic desaturation.
The study arrives during an era in which Fontan practice is becoming increasingly individualized. Earlier surgical generations often favored a more standardized approach, whereas contemporary programs increasingly tailor decisions to patient-specific anatomy, hemodynamics, ventricular performance, and institutional experience. The current data support this trend away from routine application and toward selective use. If a patient demonstrates favorable ventricular function, low pulmonary vascular resistance, acceptable transpulmonary gradients, and uncomplicated anatomy, the incremental benefit of fenestration may be limited.
At the same time, it is important not to overinterpret these findings. The study was intentionally restricted to lower-risk patients and therefore does not address the population in whom fenestration is most frequently considered. Indeed, the investigators excluded precisely those patients who many clinicians would regard as the strongest candidates for fenestration. Consequently, the study should not be interpreted as evidence against fenestration in high-risk Fontan completion. Instead, it informs a narrower but clinically relevant question: does routine fenestration confer measurable benefit in favorable-risk extracardiac Fontan patients? Based on these data, the answer appears to be no.
The findings also fit within the broader literature. Several earlier studies demonstrated reduced pleural drainage and shorter hospitalization with fenestration, while others reported minimal differences. The 2019 meta-analysis referenced by the authors similarly found little evidence of significant reductions in ventilation time, ICU stay, chest tube duration, or hospitalization. The present study therefore contributes additional prospective evidence supporting a more selective strategy.
For ACHD providers, the implications extend beyond the immediate postoperative period. Every fenestration decision carries downstream consequences. Persistent fenestrations may contribute to cyanosis, exercise limitation, paradoxical embolic risk, and later catheter-based closure procedures. Although many patients tolerate fenestrations well, their long-term management remains an important consideration within lifelong Fontan care. The absence of clear early postoperative benefits in low-risk patients raises a reasonable question: if meaningful perioperative advantages are not achieved, what justification remains for routine fenestration?
Perhaps the most valuable contribution of this study is its reminder that Fontan management continues to evolve through careful reassessment of long-held assumptions. Fenestration was introduced during an era when patient selection, surgical techniques, and perioperative care differed substantially from contemporary practice. Improvements in staging strategies, critical care, imaging, pulmonary vasodilator therapy, and surgical experience may have reduced the need for interventions once considered essential. As Fontan programs continue to refine risk stratification, routine fenestration may increasingly give way to precision fenestration.
Ultimately, this paper supports an individualized approach. Rather than asking whether all Fontan patients should receive a fenestration, clinicians should focus on identifying the specific patients most likely to benefit. In contemporary Fontan surgery, the future may belong not to routine fenestration, but to tailored fenestration guided by patient-specific risk.
Clinical Perspective
Among carefully selected low-risk extracardiac Fontan patients, routine fenestration did not significantly improve early postoperative outcomes and resulted in lower discharge oxygen saturations. These findings support a selective rather than universal approach to Fontan fenestration, reserving its use for patients with higher-risk hemodynamic or anatomical characteristics.
