New Technique Rapidly Produces Patient-Specific Vascular Grafts During Surgery

Small-diameter conduits remain a major bottleneck because suitable off‑the‑shelf implants are lacking and autologous options can be mismatched or unavailable. These constraints slow hemorrhage control and complicate pediatric and complex cardiac surgeries. To help address this challenge, bioengineers have developed a minutes‑scale method to produce custom small‑caliber vascular grafts that could be fabricated during surgery.

The platform, called Focused Rotary Jet Spinning (FRJS), was developed at Harvard University’s John A. Paulson School of Engineering and Applied Sciences (SEAS). It can create patient‑specific synthetic vascular grafts fast enough for potential intraoperative use. The work was published in Advanced Materials in 2026 and was featured on the journal’s cover.

FRJS uses high‑speed spinning and focused air streams to transform liquid polymer solutions into ultrathin fibers that are deposited on a rotating mandrel, forming tubular scaffolds that resemble native vessels. The grafts are made from a copolymer of polylactic acid and polycaprolactone. The fibrous architecture mimics extracellular matrix, provides initial mechanical strength to withstand blood pressure, and is designed to degrade as host cells rebuild tissue, with rapid endothelialization as a key goal.

For blood vessels under 6 millimeters in diameter there are no clinically approved synthetic implants, so surgeons typically harvest autologous conduits that may not fit the target anatomy or require additional incisions. The study demonstrated rapid production of grafts with tightly controlled diameters and wall thicknesses, a capability aimed at shortening time to revascularization in acute care. 

The team also anticipates use in pediatric heart surgery. Centimeter‑scale grafts suitable for small‑animal surgery were fabricated with collaborators at the University of Zurich’s Institute of Regenerative Medicine, and the researchers plan to scale to larger animal models to test performance across hemodynamic conditions. The project was supported through a longstanding partnership with NTT Research.

“We are trying to enable what we call ‘intraoperative manufacturing‘. The manufacturing speeds, customizability and flexibility of our fabrication platforms can realize grafts that are made for a particular injury or a particular patient,” said Michael Peters, research scientist at NTT Research. 

“Dentists are doing it now with 3D printing,” said Kevin Kit Parker, the Tarr Family Professor of Bioengineering and Applied Physics at Harvard University’s John A. Paulson School of Engineering and Applied Sciences. “In the case of our high‑speed additive manufacturing platforms, if you are talking about limb salvage or repairing a damaged or deformed heart, we are approaching a day where FDA‑required Good Manufacturing Practices can be met in the operating suite while the patient is on the table.”

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