Structural degeneration of bioprosthetic heart valves represents a growing clinical problem, particularly in an increasingly frequent scenario: early implantation in relatively young patients. Traditionally, redo surgical valve replacement has been considered the standard of care; however, transcatheter valve-in-valve implantation (ViV-TAVI) has become an established, less invasive alternative associated with lower perioperative risk. Despite its advantages, ViV-TAVI carries a well-recognized limitation: suboptimal hemodynamic performance, mainly driven by elevated residual gradients and prosthesis–patient mismatch. It is within this clinical threshold that intentional fracture of the surgical bioprosthesis (bioprosthetic valve fracture, BVF) has emerged as an adjunctive technique aimed at optimizing transcatheter valve expansion and refining the final procedural result.

The authors present a systematic review addressing intentional fracture of bioprosthetic surgical valves as a complement to valve-in-valve implantation using TAVI. The technical rationale of the procedure, valve types amenable to fracture, optimal timing, and available clinical and hemodynamic outcomes are analyzed. The accumulated evidence demonstrates a consistent reduction in transvalvular gradients and an increase in effective orifice area following BVF, particularly when fracture is performed after ViV-TAVI deployment. Although the technique carries a modest procedural trade-off, rates of major complications and early mortality remain low in experienced centers. The main limitation continues to be the lack of randomized trials and long-term follow-up, which constrains the generalizability of current findings.

The authors conclude that intentional fracture of bioprosthetic valves represents an effective strategy to improve ViV-TAVI hemodynamics, particularly in small surgical prostheses and when performed after transcatheter valve implantation. Despite encouraging results, they emphasize the need for larger and more homogeneous studies to better define safety, durability, and its definitive role in clinical practice.

COMMENTARY:

The primary contribution of this review is not the introduction of a novel technique, but rather its proper contextualization: providing quantitative data, limitations, and clinical framing for a maneuver that has progressively gained acceptance, yet still intimidates many operators due to its technical demands. Available evidence indicates that intentional fracture of bioprosthetic valves (BVF) achieves a clinically meaningful reduction in transvalvular gradients—clearly superior to isolated ViV-TAVI—and increases effective orifice area. However, this hemodynamic benefit, although consistent, is not always sufficient to completely eliminate prosthesis–patient mismatch, particularly in small surgical valves or in patients with larger body surface area.

From a technical standpoint, the article reinforces a critical prerequisite: not all bioprosthetic valves are amenable to fracture. Models such as Hancock II, Avalus, or Perimount 2700 fall outside the practical BVF armamentarium, whereas other valves allow complete fracture or, alternatively, partial remodeling. Accurate identification of the previously implanted surgical valve is not a trivial detail but a cornerstone of procedural planning, essential to avoid futile attempts or unnecessarily aggressive maneuvers.

Balloon selection and sizing constitute another fundamental pillar of the procedure. Current evidence supports the use of high-pressure, noncompliant balloons, with Atlas Gold and True Dilatation being the most frequently employed. In routine practice, balloon diameter is typically selected at least 3 mm larger than the internal diameter of the surgical prosthesis, a strategy associated with superior hemodynamic outcomes. Important exceptions apply: when self-expanding valves such as CoreValve are used, oversizing should be limited to 2 mm, whereas in balloon-expandable valves such as SAPIEN, the balloon should be matched to the internal diameter without oversizing. This is not an area for improvisation—clear technical rules and boundaries exist.

Regarding the transcatheter valve used for ViV-TAVI, available data suggest a hemodynamic advantage of self-expanding valves, attributed to their supra-annular leaflet position and larger effective orifice area. This advantage persists even when BVF is performed, provided that balloon positioning is appropriate to act on the frame without compromising the leaflets.

One of the most relevant messages of the review concerns procedural sequencing. Although fracture prior to transcatheter valve implantation was initially explored, current evidence clearly favors implanting the TAVI first and performing BVF afterward. This sequence is associated with lower final gradients and, more importantly, a more favorable safety profile. In contrast, BVF performed before ViV-TAVI has been associated with higher mortality without clear hemodynamic benefit, relegating this approach to highly exceptional scenarios far removed from routine practice.

From an operator’s practical perspective, recognizing true prosthetic fracture requires careful interpretation of multiple signs. During inflation of the noncompliant balloon, an abrupt pressure drop may be observed, often accompanied by a distinct tactile release and occasionally an audible click; however, this finding alone does not reliably differentiate true ring fracture from balloon rupture. In genuine prosthetic cracking, the balloon remains intact and stable, the characteristic mechanical release is perceived, and fluoroscopy may reveal discontinuity of the surgical valve ring. Once fracture is identified, further inflation adds no benefit and only increases risk; the maneuver should therefore be terminated. Prior knowledge of valve fracturability, expected pressure ranges, and correct balloon positioning (below the leaflet plane in self-expanding valves and centered in balloon-expandable valves) constitutes essential cognitive equipment for safe execution.

With respect to limitations and risks, although overall complication rates are low in experienced centers, BVF is not a benign technique. Rupture of the annulus or aortic root, with potentially catastrophic bleeding, remains the most feared complication, along with coronary obstruction. Consequently, the procedure should be avoided in patients with critically short coronary distances or prior aortic root replacement or enlargement, scenarios in which risk may clearly outweigh expected benefit.

From a real-world practice perspective, these techniques are not performed in isolation but within structured and well-organized heart valve programs. At our institution (CHUAC), with extensive experience in non-transfemoral TAVI and a growing volume of transcarotid implants led by surgeons, the valve-in-valve approach—and, in selected cases, prosthetic fracture—forms part of a continuous care pathway. Familiarity with alternative access routes, surgical control of the procedure, and meticulous imaging-based planning enable safer management of technically demanding scenarios, such as small surgical prostheses at high risk of mismatch. In this context, prosthetic fracture is not viewed as an exceptional maneuver but as another tool, reserved for specific cases within a structured and experienced program.

From a clinical standpoint, BVF should be reserved for carefully selected scenarios: patients with small surgical valves (19–21 mm) at high risk of mismatch, cases with elevated residual gradients after correctly implanted ViV-TAVI, or relatively active patients in whom even modest hemodynamic improvement may translate into meaningful functional benefit. Conversely, routine or preventive use currently lacks sufficient evidence and may represent an unnecessary liability.

Overall, this work serves as a corollary to a clear concept: bioprosthetic valve fracture is a powerful but demanding tool, whose value lies in its integration within an individualized strategy discussed by the Heart Team. In expert hands and appropriate settings, it can convert a hemodynamically suboptimal ViV-TAVI into a reasonable solution; outside that context, the balance between benefit and risk remains fragile.

REFERENCE:

Chopko TC, Afoke JN, Khan FW, Rowse PG. Bioprosthetic Valve Fracture for Transcatheter Aortic Valve-in-Valve Replacement: A Systematic Literature Review. Ann Thorac Surg. 2025;120(5):817–825. doi:10.1016/j.athoracsur.2025.01.009