Valvotomy is a procedure that opens a heart valve that has become too narrow to let blood pass through properly. Rather than removing and replacing the damaged valve, the surgeon or interventional cardiologist widens it, usually by splitting the fused edges of the valve leaflets apart. The procedure can be done through open surgery or, more commonly today, by threading a balloon-tipped catheter through a blood vessel and inflating it inside the stuck valve. The term applies across several different heart valves and even, in a less well-known application, to veins in the legs. Which valve is being treated, and whether the patient is a fetus, a child, or an elderly adult, changes almost everything about how the procedure is performed and what it achieves.
What Happens Inside the Valve
The core problem valvotomy addresses is stenosis, a narrowing caused when the thin flaps (leaflets) that open and close with each heartbeat become thickened, stiffened, or fused together along their edges. In mitral stenosis, the most common target for valvotomy worldwide, the underlying cause is almost always rheumatic heart disease, an inflammatory aftermath of untreated streptococcal throat infections. The inflammation scars the valve over years, gluing the leaflets together at the points where they normally meet, called the commissures.
The main way a balloon valvotomy increases the valve opening is by splitting those fused commissures apart. Research using echocardiographic imaging before and after the procedure has confirmed that commissural splitting is the dominant mechanism by which the valve area grows larger, and that the degree of splitting can be predicted beforehand by assessing how calcified or thickened the commissures are on ultrasound.1PubMed. Percutaneous balloon mitral valvotomy with the Inoue single-balloon catheter: commissural morphology as a determinant of outcome Anatomic studies of valves treated with balloon dilation have backed this up, showing that commissural fusion is the hallmark of mitral stenosis and commissural splitting the hallmark of a successful valvotomy.2PubMed. Anatomic basis for and morphologic results from catheter balloon valvuloplasty of stenotic mitral valves
Mitral Valvotomy for Rheumatic Heart Disease
Balloon mitral valvotomy, sometimes called percutaneous balloon mitral commissurotomy, is the most widely performed version of the procedure. It was introduced in 1984 by Kanji Inoue as a catheter-based alternative to the older surgical approach, in which a surgeon would reach into the beating heart and manually pry the fused commissures apart.3PubMed Central. Mitral balloon valvuloplasty The balloon approach avoids the need for a chest incision. Instead, a catheter is advanced through a vein, guided across the wall separating the heart’s upper chambers, and positioned inside the narrowed mitral valve. The balloon is then inflated in controlled steps to stretch the valve open.
Not every stenotic mitral valve is a good candidate. Doctors use echocardiographic scoring systems to evaluate the valve’s anatomy before deciding whether balloon valvotomy is appropriate. These scores assess factors like leaflet thickness, leaflet mobility, calcification, and the condition of the structures beneath the valve. Several scoring models exist, and researchers continue to refine them because no single score perfectly predicts who will do well.4European Heart Journal – Cardiovascular Imaging. Assessment of suitability for percutaneous mitral commissurotomy: a contemporary review of key anatomical criteria and predictive models A valve that is heavily calcified, has stiff leaflets, or has badly damaged subvalvular structures is less likely to respond well and more likely to develop complications. In those cases, surgery may be the better path from the start.
Long-Term Results After Mitral Balloon Valvotomy
For patients with favorable valve anatomy, the long-term results are genuinely good. A large study tracking patients for a median of over eight years after successful balloon mitral valvotomy found that annual mortality was very low, around 0.6%. About 8% of patients eventually needed mitral valve surgery, and about 10% underwent a repeat balloon procedure.5PubMed. Very Long Term Follow-Up After Percutaneous Balloon Mitral Valvuloplasty
Restenosis, the gradual re-narrowing of the valve over time, is the main long-term concern. In one study of nearly 500 patients, restenosis occurred in about 17% of cases. Freedom from restenosis was roughly 89% at five years, 81% at seven years, and 68% at ten years. Patients whose valves had lower echo scores at baseline, meaning more favorable anatomy, fared significantly better on all measures.6European Heart Journal. Long-term clinical and echocardiographic results after successful mitral balloon valvotomy and predictors of long-term outcome The picture that emerges is that balloon mitral valvotomy buys many patients years or even decades of good function, but it is not necessarily a permanent fix. Some will eventually need surgery.
When Restenosis Happens and the Choice Between Repeat Valvotomy and Replacement
When mitral stenosis comes back after a previous balloon valvotomy, patients and their doctors face a decision: try the balloon again, or go to mitral valve replacement surgery? Research comparing the two approaches in patients with restenosis found that outcomes were similar for the first three to four years. After that, valve replacement pulled ahead. Nine-year event-free survival was about 90% after replacement but only about 36% after a second balloon procedure.7PubMed. Comparison of long-term outcome after mitral valve replacement or repeated balloon mitral valvotomy in patients with restenosis after previous balloon valvotomy This suggests that for patients whose valves have already scarred enough to restenose, replacement may be the more durable choice, particularly when the valve anatomy has deteriorated.
A separate single-center study comparing surgical mitral valve repair with percutaneous balloon commissurotomy in patients with rheumatic heart disease found similar early outcomes, but patients who had surgical repair had a significantly lower risk of needing a reoperation on the mitral valve over a follow-up period averaging about 40 months.8PubMed. Comparison of Mitral Valve Repair Versus Percutaneous Mitral Balloon Commissurotomy for Patients With Rheumatic Heart Disease: A Single-Centre Study Mortality, however, did not differ between the groups. The tradeoff is real: balloon valvotomy is less invasive and avoids open-heart surgery, but surgical approaches tend to be more durable when the valve has significant structural damage.
Complications of Mitral Balloon Valvotomy
The most feared acute complication is severe mitral regurgitation, where the valve that was too narrow suddenly becomes too leaky. This can happen if a leaflet tears during balloon inflation rather than simply splitting at the commissure. In a series of nearly 3,900 patients, acute severe mitral regurgitation requiring emergency surgery occurred in about 1.3% of cases. The most common cause was a tear of the front (anterior) leaflet, accounting for roughly 72% of those emergencies.9PubMed. Acute severe mitral regurgitation following balloon mitral valvotomy: echocardiographic features, operative findings, and outcome in 50 surgical cases
A broader look at significant regurgitation, including cases that did not require emergency surgery, puts the rate higher. One study found that roughly 19% of patients developed at least significant mitral regurgitation after the procedure, with the mechanism varying: commissural regurgitation was the most common, followed by leaflet or subvalvular damage.10PubMed Central. Mitral Regurgitation After Percutaneous Mitral Valvuloplasty: Insights Into Mechanisms and Impact on Clinical Outcomes The risk of creating a small hole in the wall between the upper heart chambers during the transseptal puncture is another recognized complication, though follow-up studies have found these iatrogenic defects are typically small and do not cause long-term problems.11PubMed Central. Long-term follow-up of iatrogenic atrial septal defect: after percutaneous mitral balloon valvuloplasty
Aortic Valvotomy in Children
Aortic valve stenosis in children is a different disease from the age-related calcific aortic stenosis seen in older adults. Children with congenital aortic stenosis are born with a valve that did not form correctly, often with two leaflets instead of three or with leaflets partially fused together. Valvotomy is typically the first intervention these children receive, performed either surgically or with a balloon catheter.
A systematic review and meta-analysis comparing surgical valvotomy with balloon valvuloplasty in children found no difference in long-term survival or in freedom from eventually needing an aortic valve replacement. However, children who had balloon valvuloplasty needed additional procedures significantly more often. Ten-year freedom from reintervention was about 46% in the balloon group compared with about 73% in the surgical group.12PubMed Central. Surgical Valvotomy Versus Balloon Valvuloplasty for Congenital Aortic Valve Stenosis: A Systematic Review and Meta‐Analysis A more recent long-term study echoed this finding: survival was excellent overall at about 91% at 25 years regardless of approach, but children treated initially with balloon valvuloplasty tended to need valve replacement earlier than those who had surgery first.13The Journal of Thoracic and Cardiovascular Surgery. Long-term outcomes of initial intervention for congenital aortic stenosis Patient factors like the severity of stenosis at birth and the presence of other heart abnormalities mattered more for survival than the choice of initial procedure.
Aortic Valvotomy in Adults
In adults, aortic stenosis is usually caused by age-related calcification, and balloon aortic valvuloplasty has a very different role than it does in children. On its own, balloon dilation of a heavily calcified adult aortic valve provides only temporary relief. The valve tends to re-narrow within months. For this reason, standalone balloon aortic valvuloplasty has largely been replaced by transcatheter aortic valve replacement, or TAVR, in which a new valve is implanted inside the old one via catheter.
Where balloon aortic valvuloplasty still plays a role is as a bridge, a stopgap measure to stabilize a patient who is too sick for immediate TAVR or who needs time for other medical issues to be managed first. About 40% of patients who undergo balloon aortic valvuloplasty go on to receive TAVR, most within 90 days.14JACC: Cardiovascular Interventions. Balloon Aortic Valvuloplasty as a Bridge to Aortic Valve Replacement: A Contemporary Nationwide Perspective One nationwide study using propensity-score matching found that patients who had TAVR after a prior balloon procedure had similar in-hospital outcomes to patients who went directly to TAVR. However, a separate analysis found that using balloon valvuloplasty as a bridge was associated with higher in-hospital mortality compared to going straight to TAVR, with mortality of about 5.6% versus 1.3%.15PubMed. Balloon aortic valvuloplasty bridge to transcatheter aortic valve replacement is associated with worse in-hospital mortality Some of this difference likely reflects the fact that patients who need a bridge procedure are sicker to begin with. The debate over when bridging helps and when it adds risk without benefit is ongoing.
Balloon aortic valvuloplasty also turns up as a preparatory step during TAVR itself. Inflating a balloon inside the stenotic valve right before deploying the replacement valve has traditionally been considered a standard part of the implantation process, used to pre-dilate the valve and make room for the prosthesis.16PubMed Central. Transcatheter Aortic Valve Implantation With or Without Preimplantation Balloon Aortic Valvuloplasty: A Systematic Review and Meta-Analysis As newer self-expanding valve designs have improved, some centers have started skipping this pre-dilation step, though practice varies.
Pulmonary Valvotomy
Pulmonary valve stenosis, a narrowing of the valve controlling blood flow from the right side of the heart to the lungs, is one of the success stories of balloon valvotomy. It is usually congenital and often diagnosed in childhood, though milder cases can present later in life. Balloon pulmonary valvuloplasty has become the treatment of choice, preferred over surgery in most cases.
A systematic review of the evidence found conclusive support for immediate and sustained relief of obstruction after balloon pulmonary valvuloplasty. Stenosis recurred in about 10% of patients, typically when the balloon used was undersized relative to the valve ring or when the immediate result left a residual gradient above 30 mmHg. In those cases, a repeat balloon procedure with a larger balloon was usually effective.17PubMed Central. Balloon pulmonary valvuloplasty: A systematic review Results in adolescents and adults have been similarly encouraging. In one study of 53 patients treated in late adolescence or adulthood, the pressure gradient across the valve dropped dramatically, and the valve orifice nearly doubled in diameter. Minor valve leakiness appeared in about 13% of patients right after the procedure but resolved in all of them at follow-up.18PubMed. Percutaneous balloon valvuloplasty for pulmonic stenosis in adolescents and adults
Long-term follow-up in children has confirmed that the benefits hold up over years, with excellent short-, intermediate-, and long-term outcomes and a strong safety profile.19PubMed Central. Long-term Results of Balloon Pulmonary Valvuloplasty in Children with Congenital Pulmonary Valve Stenosis The main long-term concern is that some patients develop pulmonary valve leakiness (insufficiency) over many years, and a small number eventually need the valve replaced. Getting the balloon size right during the initial procedure, using a balloon-to-annulus ratio of about 1.2 to 1.25, appears to minimize both the risk of recurrent stenosis and the risk of creating too much leakiness.
Valvotomy During Pregnancy
Rheumatic mitral stenosis is common in many parts of the world, and young women with the condition can run into serious trouble during pregnancy. The increased blood volume and heart rate of pregnancy strain a narrowed mitral valve, sometimes pushing a woman who was previously managing well into heart failure. Valve surgery during pregnancy carries high risks for the fetus, which makes balloon mitral valvotomy an attractive alternative.
Studies of pregnant women undergoing balloon mitral valvotomy have shown high procedural success rates, typically above 95%, and favorable maternal and fetal outcomes. In one study of 50 pregnant women, there was no maternal mortality, the procedure succeeded in 96% of patients, and over 80% delivered at term vaginally.20PubMed Central. Maternal and fetal outcomes in pregnant women undergoing balloon mitral valvotomy for rheumatic mitral stenosis A larger series of 97 pregnant women reported a 98% success rate, though there was one maternal death due to complications from intrauterine fetal demise and subsequent clotting problems.21PubMed Central. Immediate and long-term outcomes of balloon mitral valvotomy in pregnancy Overall, the evidence supports balloon mitral valvotomy as a preferred intervention for pregnant women with symptomatic moderate-to-severe rheumatic mitral stenosis, offering substantial improvement in symptoms and hemodynamics while avoiding the risks of open surgery and cardiopulmonary bypass to the fetus.22Journal of Invasive Cardiology. Percutaneous Balloon Mitral Valvuloplasty During Antenatal Care and Apgar Score: The ANC-Valve Study
The procedure is typically performed in the second trimester when possible, after the critical early period of organ formation but before the later stages when the growing uterus and increased blood volume create more hemodynamic stress. Fluoroscopy, which uses radiation, is kept to a minimum, with lead shielding over the abdomen and reliance on echocardiographic imaging to guide the catheter whenever feasible.
How Imaging Guides the Procedure
Balloon valvotomy is not done blind. Echocardiography, the use of ultrasound to visualize the heart in real time, has become central to guiding the procedure safely. Transesophageal echocardiography, in which an ultrasound probe is passed into the esophagus behind the heart, provides detailed views during the procedure. One study found that using transesophageal echo guidance cut procedure time by more than a third compared to fluoroscopy alone and helped reduce complications from the transseptal puncture and from balloon inflation.23PubMed. The advantages of On-line transesophageal echocardiography guide during percutaneous balloon mitral valvuloplasty
Intracardiac echocardiography, where a tiny ultrasound transducer is mounted on the catheter itself and placed inside the heart, is a newer option. It can guide the transseptal puncture, help position the balloon, and allow immediate assessment of the result, including detecting new mitral regurgitation with color Doppler imaging, all without requiring general anesthesia (which transesophageal echo usually does).24PubMed. Initial clinical experience with intracardiac echocardiography in guiding balloon mitral valvuloplasty: technique, safety, utility, and limitations The choice between imaging approaches depends on the center, the patient, and the operator’s experience.
Fetal Aortic Valvotomy
One of the most remarkable extensions of valvotomy is performing it on a fetus still in the womb. In some cases of severe aortic stenosis diagnosed during the second trimester of pregnancy, the obstruction prevents the left side of the fetal heart from developing normally. Left uncorrected, the heart can progress to hypoplastic left heart syndrome, a condition in which the left ventricle is too small to function after birth and requires a series of complex surgeries or a heart transplant.
Fetal aortic valvuloplasty involves inserting a needle through the mother’s abdomen, through the uterine wall, through the fetal chest, and into the fetal heart, then inflating a tiny balloon inside the stenotic aortic valve. When technically successful, the procedure has been shown to alter left heart growth, preventing the progression to hypoplastic left heart syndrome in a subset of cases and allowing some of these children to be born with a heart capable of functioning with two ventricles rather than one.25PubMed Central. Predictors of technical success and postnatal biventricular outcome after in utero aortic valvuloplasty for aortic stenosis with evolving hypoplastic left heart syndrome Early experience demonstrated that careful patient selection and ideal fetal positioning were critical, and that when the valve dilation was achieved successfully, it could prevent left heart growth arrest.26PubMed. Balloon dilation of severe aortic stenosis in the fetus: potential for prevention of hypoplastic left heart syndrome This remains a highly specialized procedure, performed at only a handful of centers worldwide, and is still considered investigational in many contexts. But the concept of intervening before birth to change the trajectory of a developing heart represents one of the frontiers of cardiac intervention.
Valvotomy Outside the Heart
The word valvotomy also shows up in vascular surgery, though the setting is entirely different. Veins in the legs contain small one-way valves that prevent blood from flowing backward under the pull of gravity. When surgeons perform an “in situ” saphenous vein bypass, a procedure to reroute blood flow around a blocked leg artery using the patient’s own vein, they need to disable those venous valves so blood can flow in the opposite direction through the repurposed vein. This is done with a valvotome, a small cutting instrument passed through the vein to incise the valve leaflets. Studies of these instruments have found that they do not compromise the long-term patency of the bypass graft.27Journal of Vascular Surgery. Instrumental evolution of the valve incision method of in situ saphenous vein bypass
More recently, balloon valvotomy of venous valves has found a role in an experimental procedure called deep venous arterialization. In patients with severe, otherwise untreatable leg ischemia, where no artery can deliver blood to the foot, surgeons have tried connecting an artery to a vein and using the venous system in reverse to perfuse the tissue. Making this work requires destroying the venous valves that would block the reverse flow. Catheter-based balloon valvotomy of the saphenous and tarsal vein valves is one technique used to accomplish this.28PubMed. Hybrid Deep Venous ARterialisation (DVAR) for No-Option Chronic Limb Threatening Ischemia
Cost and Access in Resource-Limited Settings
Rheumatic heart disease disproportionately affects people in low- and middle-income countries, where access to cardiac surgery is limited and expensive. Balloon mitral valvotomy has an inherent advantage in these settings because it avoids open-heart surgery, requires a shorter hospital stay, and can be performed with less infrastructure than valve replacement. But even the catheter equipment has cost barriers. The Inoue balloon, the most widely used device, is expensive enough that its cost alone can limit access. Comparative studies have evaluated less expensive balloon alternatives, such as the double-lumen Accura balloon, and found similar safety and effectiveness at midterm follow-up, with the added benefit of being reusable more times and considerably cheaper.29PubMed. Comparative study on safety, efficacy, and midterm results of balloon mitral valvotomy performed with triple lumen and double lumen mitral valvotomy catheters Making effective balloon valvotomy accessible with affordable equipment is not a minor technical footnote; for young patients in sub-Saharan Africa or South Asia with rheumatic mitral stenosis, it can be the difference between a functional life and progressive disability.