The modified Bentall procedure is an open-heart operation that replaces the aortic root, the aortic valve, and the first segment of the ascending aorta in a single step, using a composite graft with a prosthetic valve already sewn inside a synthetic tube. The “modified” part refers to how the coronary arteries are reconnected: rather than wrapping the old aortic wall around the graft (the original 1968 technique), the surgeon cuts small buttons of tissue around each coronary opening and stitches them directly into holes made in the new graft. That seemingly modest change turned a procedure plagued by late bleeding into one of the most durable operations in cardiac surgery, though it remains a major undertaking with real risks worth understanding.
From the Original Bentall to the Button Technique
Hugh Bentall first described his composite graft approach in the late 1960s, addressing a problem that had stymied surgeons: when the aortic valve, the sinuses of Valsalva, and the ascending aorta are all diseased, patching one part at a time is unreliable. Bentall’s idea was to replace everything at once with a single unit. In his original version, the coronary arteries were left in place and the remnant of the native aorta was wrapped around the graft like a sleeve, creating a space between the old wall and the new graft. That wrap helped control bleeding at first, but over months and years the space could fill with blood and form dangerous pseudoaneurysms.
The modification that solved this, now universally called the “button Bentall” or simply the modified Bentall procedure, involves excising the tissue from each of the three aortic sinuses, leaving only a small rim. The coronary arteries are then separated from the surrounding sinus tissue as small full-thickness buttons of aortic wall, mobilized just enough to reach the graft without tension, and sutured directly into corresponding openings in the Dacron tube.1Operative Techniques in Thoracic and Cardiovascular Surgery. The Button Bentall Procedure By eliminating the wrap-around space entirely, the button technique removed the main source of late pseudoaneurysm formation. This is the version performed today whenever surgeons refer to a “Bentall procedure,” though many still use the word “modified” to distinguish it from the historical original.2PubMed Central. A Bentall Is Not a Bentall Is Not a Bentall: The Evolution of Aortic Root Surgery
Who Needs This Operation
The modified Bentall is indicated when disease affects the aortic valve and the aortic root together, making it impossible or impractical to repair or replace just one part. The most common reasons are aortic root aneurysm, acute aortic dissection, connective-tissue disorders like Marfan syndrome, bicuspid aortic valve disease with root dilation, degenerative disease, and prosthetic valve endocarditis. In one large series of nearly 1,500 patients, aneurysms accounted for the vast majority of cases, with dissections and endocarditis making up smaller but significant shares.3PubMed. Long-term survival and operative outcomes of the Bentall procedure for aortic root aneurysm, aortic dissection, and endocarditis A smaller single-surgeon series found dissection and Marfan syndrome each responsible for about a third of cases, reflecting how the case mix varies between centers.4PubMed Central. Aortic Root Pathologies and Surgical Management: Insights From a Single Surgeon’s Experience
The common thread is that the aortic root has become structurally compromised. A person with an aortic root aneurysm above roughly 5 centimeters, or above 4.5 centimeters in Marfan syndrome, faces a rising risk of rupture or dissection. When the aortic valve is also significantly regurgitant or stenotic, or when the tissue quality is too poor for valve-sparing repair, the Bentall procedure offers a one-stop solution rather than cobbling together separate fixes.
Mechanical Versus Biological Grafts
Inside the composite graft is either a mechanical valve or a bioprosthetic (tissue) valve, and the choice between them is one of the biggest decisions a patient and surgeon face before the operation. A mechanical valve is extremely durable, potentially lasting the rest of the patient’s life, but it requires lifelong blood-thinning medication (typically warfarin) to prevent clots from forming on its surfaces. A bioprosthetic valve avoids the need for long-term anticoagulation in most cases but will gradually wear out, potentially requiring another procedure years down the road.
In terms of raw survival, multiple propensity-matched studies show no significant difference between the two. A large matched analysis of 154-patient groups found mean survival of about 16 years in both mechanical and biological Bentall patients. However, the mechanical group had a longer average time before needing a redo operation on the root itself.5PubMed Central. Mechanical Versus Biological Bentall Procedure: A Propensity-Score Matching Analysis of 548 Consecutive Patients A separate matched study from a series of over 1,100 patients found comparable hospital mortality and midterm outcomes between the two graft types, with freedom from reoperation on the aortic root remaining above 93% at seven years in the mechanical group compared with a similar rate in the biological group, though the biological group showed a trend toward more reinterventions.6European Journal of Cardio-Thoracic Surgery. Biological versus mechanical Bentall procedure for aortic root replacement: a propensity score analysis of a consecutive series of 1112 patients
For younger patients who can tolerate lifelong anticoagulation, the mechanical option trades the inconvenience and bleeding risk of warfarin for strong protection against structural valve failure. Older patients, or those who cannot safely take blood thinners, are more often steered toward bioprosthetic grafts, accepting the possibility that the valve may need replacement in 10 to 20 years. That second operation may now sometimes be performed through a catheter-based valve-in-valve approach rather than full redo surgery, though the evidence on that approach in Bentall patients is still evolving.
Operative Risk and Long-Term Survival
The modified Bentall is a major cardiac operation performed on cardiopulmonary bypass, and it carries a meaningful operative mortality. Across studies, hospital death rates for elective cases tend to fall in the range of about 5 to 7%, but emergency cases, particularly acute dissections, carry considerably higher risk. One retrospective analysis reported an overall in-hospital mortality of about 12%, with elective cases at roughly 7% and emergencies climbing to nearly 29%.7Journal of Heart Valve Disease. Early Postoperative Outcomes Following the Modified Bentall Procedure: A Retrospective Analysis from A Single Tertiary Care Centre Another series reported hospital mortality just under 7%, with aortic valve calcification, kidney failure, and post-operative heart failure identified as predictors of early death.8Japanese Heart Journal. Analysis of Perioperative Risk Factors in Mortality and Morbidity after Modified Bentall Operation These numbers underscore a point that patients preparing for this surgery should understand: when the operation is planned and performed in stable conditions, the risk is far lower than when it happens as a rescue during an aortic catastrophe.
Among those who survive the operation, long-term outcomes are generally encouraging. One 18-year follow-up of modified Bentall procedures using a flanged graft technique found that about 94% of patients with biological grafts and 93% with mechanical grafts were alive at five years. At ten years, freedom from death was roughly 79% in the mechanical group.9PubMed Central. Long-term results of modified bentall procedures: 18-year experience of the flanged technique A separate long-term analysis of a flanged composite prosthesis reported an actuarial survival of about 84% at 5 years, dropping to around 64% at 15 years and about 52% at 25 years, reflecting the reality that many of these patients have underlying connective-tissue disorders or other chronic conditions that affect their overall life expectancy independently of the graft itself.10J-STAGE / Annals of Thoracic and Cardiovascular Surgery. Long-Term Results of Modified Bentall Procedure Using Flanged Composite Aortic Prosthesis
How It Compares to Valve-Sparing Root Replacement
Not everyone with an aortic root aneurysm needs a new valve. When the aortic valve leaflets are still in good shape, surgeons may be able to save them using a valve-sparing root replacement, known by the names of its two main variants: the David procedure (reimplantation) and the Yacoub procedure (remodeling). In these operations, the surgeon replaces the diseased root with a synthetic graft but tucks the patient’s own valve leaflets back inside, avoiding a prosthetic valve entirely. That means no mechanical click, no lifelong warfarin, and no future bioprosthetic wear-out.
The trade-off is durability of the repair. In one propensity-matched comparison, no patients in the Bentall group needed reoperation for valve problems, while about 13% of David procedure patients required reoperation for worsening aortic insufficiency. Long-term survival in that study was actually higher in the Bentall group after matching.11Scientific Reports. Long term outcomes of valve sparing aortic root replacement versus conventional aortic root replacement using a mechanical prosthesis by propensity score matching However, selection effects are at work: Bentall patients often have worse baseline valve disease, while valve-sparing patients are selected precisely because their valves look good. A study of 140 Marfan syndrome patients found no operative deaths in either group, but valve-sparing patients had significantly fewer thromboembolic events (about 1% versus 9% in the Bentall group). Root reoperation rates were low in both groups, and after adjustment for the differing baseline characteristics, the choice of procedure did not independently predict death.12The Annals of Thoracic Surgery. Aortic Root Operations for Marfan Syndrome: A Comparison of the Bentall and Valve-Sparing Procedures
In acute aortic dissection, a study comparing Bentall operations with modified Yacoub and David procedures found similar hospital mortality and five-year survival across all three approaches, suggesting that valve-sparing options are safe even in emergencies when the valve itself is suitable.13PubMed. Valve-sparing root reconstruction does not compromise survival in acute type A aortic dissection The bottom line for patients: if your surgeon says your own valve can be spared, that is likely worth pursuing, especially if you want to avoid anticoagulation. But if the valve is damaged, thickened, or severely leaking, the Bentall is the more predictable choice, and its long-term track record is strong.
The Coronary Button Problem
The part of the operation that causes the most anxiety among surgeons is reconnecting the coronary arteries. Each button of native tissue must be sewn to the graft in a way that provides a wide, tension-free opening for blood flow. If the anastomosis is too tight, the coronary artery can kink. If the suture line does not hold perfectly, blood can leak behind the button and form a pseudoaneurysm, a pressurized pouch of blood contained only by surrounding tissue. These pseudoaneurysms are rare but dangerous, and they may not show up for months or years after surgery. One reported case involved a pseudoaneurysm at the right coronary button caused by a defective knot in the suture material, discovered on imaging and repaired under deep hypothermic circulatory arrest.14PubMed Central. Right Coronary Artery Button Pseudoaneurysm After the Modified Bentall Procedure
Beyond pseudoaneurysm, imaging studies of asymptomatic patients years after a Bentall procedure have found that dilation at the coronary button attachment site is essentially universal. One CT study performed at a median of about six years after surgery found that every patient had enlargement at at least one coronary button site, with the average diameter at the attachment point being roughly 1.7 times the width of the adjacent normal coronary artery. A third of the patients also had dilation of the aorta beyond the end of the graft. None of these patients were symptomatic, but the findings illustrate why ongoing surveillance is important.15Journal of Cardiovascular Computed Tomography. Coronary ostial morphology after modified Bentall operation assessed with dual-source multidetector computed tomography
Graft Infection
Infection of the synthetic graft after a Bentall procedure is uncommon but serious. A systematic review found that graft infections were overwhelmingly caused by gram-positive bacteria and tended to appear late, well after the initial recovery period. Treatment usually required extended courses of antibiotics combined with surgery, though reoperation was not always feasible depending on the patient’s condition.16PubMed. Graft infection after a Bentall procedure: A case series and systematic review of the literature The difficulty of treating graft infection is one reason that surgeons take extensive precautions with sterile technique and antibiotic prophylaxis during the original operation. Patients who develop unexplained fevers, fatigue, or signs of sepsis months to years after a Bentall should have the graft evaluated, typically with CT angiography or echocardiography, even if the initial recovery went smoothly.
How Blood Flows Through the New Root
A synthetic tube does not behave quite like a living aortic root. The natural sinuses of Valsalva create small eddies that help the aortic valve leaflets close efficiently and distribute mechanical stress evenly across the aortic wall. A straight Dacron graft replaces those sinuses with a smooth cylindrical surface, which changes the flow patterns downstream. Computational modeling based on MRI data has shown that patients with a standard composite valve-conduit have slightly reduced helical flow in the aorta and somewhat higher wall shear stress compared to people with normal anatomy.17PubMed. Assessment of Hemodynamic Conditions in the Aorta Following Root Replacement with Composite Valve-Conduit Graft
Whether these flow differences matter clinically over decades is still being studied. Some newer graft designs, like the BioValsalva conduit, incorporate synthetic pseudo-sinuses that attempt to mimic the natural root geometry. MRI-based simulations of these grafts have shown that wall shear stress and flow patterns in the ascending aorta are more similar to those in healthy subjects, with the main remaining difference being a degree of helical flow near the suture line.18PubMed Central. In-vivo assessment of the morphology and hemodynamic functions of the BioValsalvaâ„¢ composite valve-conduit graft using cardiac magnetic resonance imaging and computational modelling technology For the typical patient, these distinctions are unlikely to drive the choice of graft, but they reflect the ongoing engineering effort to make synthetic roots behave more like natural ones.
Life After a Bentall Procedure
Recovery from a modified Bentall typically involves a week or so in the hospital, followed by several weeks of restricted activity at home. Like other open-heart operations involving a sternotomy, the breastbone needs time to heal, and patients are generally advised to avoid heavy lifting for about two to three months. Most people return to normal daily activities within that window, though return to physically demanding work or competitive exercise takes longer.
Long-term quality of life is an area where the data paints an honest but imperfect picture. A study measuring standardized quality-of-life scores found that patients who had undergone ascending aorta replacement, including Bentall procedures, scored lower than the general population in both physical and mental health domains.19PubMed Central. The Long-Term Outcome and Quality of Life after Replacement of the Ascending Aorta That gap is real, but it is hard to separate the effect of the surgery itself from the effect of the underlying disease. Many Bentall patients have Marfan syndrome or other connective-tissue conditions that affect joints, vision, and overall energy. Others had their surgery during a life-threatening dissection, which can leave lasting psychological effects. Patients with mechanical valves also deal with the audible click of the valve and the routine of INR monitoring for warfarin dosing, both of which some people find intrusive.
The Modified Bentall in Children
Aortic root aneurysms in children are rare but do occur, most often in the setting of genetic connective-tissue disorders like Marfan syndrome and Loeys-Dietz syndrome. The modified Bentall has been performed in pediatric patients, though the technical challenges are amplified. A child’s anatomy is smaller and still growing, which means the graft size must be carefully chosen. In one series, children who underwent composite graft replacement had a mean age of about 10 years and nearly all had moderate to severe aortic valve leaking before surgery. Some of these children required enlargement of the aortic annulus to accommodate an adult-sized graft, using a technique called the Konno principle that involves incising and patching part of the heart’s outflow tract.20European Journal of Cardio-Thoracic Surgery. Aortic root replacement in children: a word of caution about valve-sparing procedures
Because children have decades of growth and activity ahead of them, the valve-sparing approach is generally preferred when the valve is salvageable. But when the valve is badly damaged or the anatomy makes repair unreliable, the Bentall remains an option. A case report of a 4-year-old with Loeys-Dietz syndrome who underwent a modified Bentall with a novel “trap-door” coronary reimplantation technique showed an encouraging short-term result, with the child asymptomatic more than a year later.21PubMed Central. Modified pediatric Bentall procedure: A novel technique in a rare case These cases remain the exception, but they show the procedure’s versatility in situations where few good options exist.
Brain Protection During Surgery
When the aortic arch needs attention alongside the root, or when the distal anastomosis must be performed with an open technique, the surgeon has to stop or drastically reduce blood flow to the body for a period. To protect the brain during this interval, teams use hypothermic circulatory arrest, cooling the body to slow metabolic demand. Some centers add selective cerebral perfusion, continuing to deliver oxygenated blood specifically to the brain through a cannula in one of the head-bound arteries while the rest of the circulation is paused. This is accomplished by clamping or snaring the innominate artery and directing perfusion through a separate line while the open repair is carried out under controlled conditions.22Journal of the Egyptian Society of Cardio-Thoracic Surgery. Moderate versus deep hypothermic circulatory arrest for ascending aorta and aortic arch surgeries using open distal anastomosis technique Not every Bentall operation requires circulatory arrest; straightforward root replacements that do not involve the arch can be done with a simple cross-clamp. But understanding that brain-protective strategies exist is reassuring for patients facing more extensive repairs.
Why Lifelong Monitoring Matters
Even when the modified Bentall goes perfectly, the operation does not produce a normal aorta. Synthetic grafts do not grow, stretch, or remodel the way native tissue does. The junctions between the graft and the native aorta, and between the coronary buttons and the graft, are permanent points of potential concern. As noted in imaging studies, coronary button sites tend to dilate over time, and the native aorta downstream of the graft can continue to enlarge, especially in patients with underlying connective-tissue disease. CT angiography is the primary tool for surveillance, and most patients are followed with periodic scans to check for dilation, pseudoaneurysm, graft detachment, or new dissection in untreated segments of the aorta. The frequency of imaging varies by center and by patient risk profile, but many aortic programs recommend annual or biennial scans indefinitely. For patients with Marfan or similar genetic conditions, surveillance extends to the entire aorta, not just the replaced segment, because disease can progress in the descending aorta and branches decades after the root has been fixed.