A modified 'hemi-UFO' procedure with a custom-made bovine pericardial conduit successfully treated aortic root abscess with intervalvular fibrous body involvement while preserving the native mitral valve in a high-risk re-do case, with an uneventful 3-year follow-up.
Key Findings
Results
A modified hemi-UFO procedure was successfully performed in a 71-year-old male with aortic prosthesis endocarditis and intervalvular fibrous body involvement, preserving the native mitral valve.
The patient had previously undergone aortic valve replacement with a 23-mm prosthesis via partial upper mini-sternotomy.
Large vegetation and severe regurgitation of the aortic valve prosthesis were identified on echocardiogram eight weeks after the initial surgery.
Intraoperatively, the aortic prosthesis was found to be partially torn out with circular infection of the aortic annulus and an abscess connecting to the left atrium.
The tissue of the left atrial roof was partially destroyed, described as 'similar to a phlegmonous infection.'
Unlike the standard UFO procedure which requires replacement of both valves regardless of infection size, the hemi-UFO modification allowed preservation of the native mitral valve.
Results
The patient carried an extremely high operative mortality risk as calculated by EuroSCORE II of 50.64%.
The EuroSCORE II risk of death following reintervention heart surgery was calculated as 50.64%.
The case was classified as a high-risk re-do operation.
Despite the high calculated risk, the patient was transferred to the intensive care unit with no inotropes and in sinus rhythm.
The 3-year follow-up was described as uneventful.
Results
A custom-made bovine pericardial conduit with a 25-mm valve prosthesis was fabricated and used to reconstruct the aortic root and associated structures.
The conduit prosthesis was constructed from bovine pericardium incorporating a 25-mm valve prosthesis.
Two thirds of the ascending aorta were replaced with reimplantation of the coronary arteries using the Bentall-de Bono technique.
All sutures were pericardium-pledgeted and passed through a bovine pericardial patch.
The bovine pericardial patch formed a new mitral annulus and was used for closure of the left atrial roof.
Results
Radical resection required reconstruction of the intervalvular fibrous body, the roof of the left atrium, and the mitral annulus in all three anterior segments (A1, A2, and A3).
The infected tissue was radically resected up to the intervalvular fibrous body (IVFB).
The left atrial roof was opened to facilitate resection and subsequent reconstruction.
Reconstruction encompassed the IVFB, roof of the left atrium, and mitral annulus in the anterior (A1), middle (A2), and posterior (A3) segments.
The new aortic valve prosthesis was stabilized and implanted with sutures through the opened left atrial roof, with stitches beginning close to the anterior mitral leaflet region and ending in the direction of the left ventricular outflow tract.
Background
The standard UFO procedure, an established technique for extensive endocarditis involving the intervalvular fibrous body, mandates replacement of both the aortic and mitral valves regardless of infection size.
The UFO procedure is described as 'an established surgical technique to treat extensive endocarditis of the aortic or mitral valve with involvement of the intervalvular fibrous body (IVFB).'
The technique allows for radical resection of all infected tissue.
The authors state it is 'unavoidable to replace both valves' independently of the size of the infected region in the standard UFO procedure.
The modified hemi-UFO procedure presented here represents a departure from this requirement by preserving the native mitral valve.
What This Means
This case report describes the surgical treatment of a 71-year-old man who developed a serious infection (endocarditis) of an artificial aortic heart valve that had been implanted only eight weeks earlier. The infection had spread to form an abscess that destroyed surrounding heart tissue, including the fibrous body connecting the aortic and mitral valves and part of the roof of the left atrium. The calculated risk of dying from the necessary repeat surgery was over 50%, making this an exceptionally dangerous situation.
The surgical team performed a modified version of an established procedure called the 'UFO procedure,' which is typically used for severe heart valve infections but normally requires replacing both the aortic and mitral valves. In this modified 'hemi-UFO' approach, the surgeons were able to remove all infected tissue, reconstruct the destroyed structures using patches and a custom-made tube (conduit) fashioned from bovine (cow) pericardium containing a new artificial valve, and replace part of the aorta — all while saving the patient's own mitral valve. The patient left the intensive care unit without needing heart-supporting drugs and with a normal heart rhythm, and remained well at a three-year follow-up.
This research suggests that in carefully selected cases of severe aortic valve prosthesis infection involving adjacent heart structures, a modified surgical approach may allow complete removal of infected tissue and full reconstruction while avoiding the need to replace a functioning mitral valve. This could be meaningful for future patients facing similarly complex re-do cardiac surgeries, as preserving a native valve may reduce procedural complexity and associated risks, though conclusions are limited given this is a single case report.
Zwaans V, Iske J, Pitts L, Starck C, Grubitzsch H, Kempfert J, et al.. (2026). Aortic root abscess in a high-risk case requiring modified hemi-UFO procedure with custom-made pericardial conduit - a case report.. Journal of cardiothoracic surgery. https://doi.org/10.1186/s13019-026-04318-z