Heart bypass surgery: the incision is now ‘mini’ and recovery is quicker

This news is important because it is not merely a question of a more elegant technique or a smaller scar for aesthetic reasons, but rather a way of speeding up a patient’s recovery following a life-saving operation

by Maria Rita Montebelli

6 October 2026

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Medical Team Performing Surgical Operation in Modern Operating Room Gorodenkoff - stock.adobe.com

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Versione italiana

Key points

What is a coronary artery bypass graft used for?
The international MIST study published in The Lancet
But when it comes to recovery, the difference is clear
Minimally invasive bypass surgery requires highly specialised teams

4' min read

Translated by AI

Versione italiana

Gaining access to the chest to save the heart, but doing so with the utmost care, without having to ‘force open’ the ribcage. This, in a nutshell, is the promise of the new coronary surgery technique described in MIST, an international study published in *b* *The Lancet* . And the news is significant because it is not merely a matter of a more elegant technique or a smaller scar for aesthetic reasons, but a way of speeding up the patient’s recovery following life-saving surgery. The study compared traditional bypass surgery, which is performed via a median sternotomy, with that carried out via a minimally invasive approach of just a few centimetres.

What is the purpose of a coronary artery bypass graft

Coronary artery bypass grafting (CABG) is a vital procedure for patients with complex coronary artery disease and multiple diseased coronary arteries. When one or more coronary arteries are narrowed or blocked, the surgeon creates a new pathway – a sort of bridge – to allow blood to flow, using a blood vessel taken from the patient themselves (usually a vein from the legs or an artery from the chest). The blood can then flow once more, bypassing the ‘blockage’, to resume nourishing the heart muscle. It is a well-established procedure with a long history of effectiveness and durability.

The problem is that, to reach the heart, the traditional approach involves a median sternotomy: the sternum (the central bone of the chest to which the ribs are attached) is opened lengthways to allow the surgeon to operate on the heart. However, the new procedure tested in the MIST study and developed by the team led by Marc Ruel (University of Ottawa, Canada) changes the way the heart is accessed. Instead of opening the sternum, the surgeon accesses the heart via a small lateral incision in the chest, measuring approximately 5–7 centimetres. This is therefore not a ‘scalpel-free’ procedure, but a different and technically more complex way of achieving the same objective: restoring oxygenated blood to the heart muscle.

The international MIST study published in The Lancet

It’s all very well to minimise surgical trauma, then; but does this compromise the quality of the bypass?

The MIST trial was launched to answer this question; it is an international, multicentre, randomised study conducted at seven centres in Canada, India, China, Germany, the United States and Japan. It involved 170 patients with multivessel coronary artery disease: 86 were assigned to minimally invasive bypass surgery and 84 to conventional bypass surgery via sternotomy. The median age was 67 years and 91 per cent of participants were men. In both groups, an average of three bypass grafts were performed, and the use of arterial grafts was virtually identical: 47 per cent in the minimally invasive group compared with 46 per cent in the traditional surgery group. In other words, the small incision did not result in poorer or incomplete revascularisation.

But when it comes to recovery, the difference is clear

Patients who underwent the minimally invasive procedure spent approximately 6.4 hours less on mechanical ventilation and required fewer blood transfusions. At 30 days, they reported better physical functioning. And one year on, the outcomes of CABG were similar between the two groups. In short, the MIST study demonstrates that with the minimally invasive procedure, the heart is revascularised just as effectively, but the patient’s recovery is much faster.

And this represents a shift in perspective. Until now, the focus has been solely on the ‘success of the operation’. Today, we also ask: how is the patient doing after the operation? The MIST trial also took into account the outcome from the patient’s perspective, not just that measured by the cardiac surgeon.

Of course, these results do not simply spell the end of traditional bypass surgery, nor do they imply that minimally invasive bypass should become the new standard for everyone. In an editorial published in The Lancet, Gianluca Torregrossa and Faisal Bakaeen (Cleveland Clinic, USA), despite the title (“Beyond the incision: the MIST study redefines contemporary coronary surgery”), play down the findings, emphasising that the trial was conducted in centres with extensive experience and that pre-operative quality-of-life scores were not reported. Furthermore, there was no systematic long-term follow-up to check whether all the new bypasses were still patent.

Minimally invasive bypass surgery requires highly specialised teams

For the first time, however, an international randomised study has shown that minimally invasive coronary bypass surgery can achieve the same standard of revascularisation as traditional surgery, whilst offering a better physical recovery in the first few months. But it is not a technique suitable for everyone: highly specialised teams are required.

This new surgical technique requires even greater expertise. The surgeon must be able to perform complex revascularisation whilst working within a much smaller space. The professionals involved in the MIST study already had considerable experience in minimally invasive coronary surgery. For this reason, the results achieved cannot be automatically applied to every operating theatre or every surgical team.

And the future of bypass surgery will not lie in ‘smaller incisions’, but in increasingly specialised surgery. Even now, bypass surgery is no longer a ‘standardised’ procedure – that is, one always carried out in the same way: there are techniques involving multiple arteries, procedures without a heart-lung machine, minimally invasive and robotic approaches, hybrid strategies and different methods for selecting the vessels to be used as grafts.

The key takeaway from the MIST study, therefore, is not that ‘the old bypass is outdated’, but that it is possible to reduce the trauma of the operation without compromising the quality of revascularisation, in selected patients and at highly experienced centres capable of performing this procedure.