USZ: One Third of Bypass Surgeries Minimally Invasive
Gentle Heart Surgery at University Hospital Zurich
The University Hospital Zurich increasingly uses an access route between the ribs for selected bypass surgeries, rather than a full sternum opening. The MICS-CABG procedure may facilitate physical recovery after the operation. However, its long-term superiority over established sternotomy surgery is not conclusively proven.
In coronary artery disease, narrowed coronary vessels can be bypassed. This procedure typically involves a median sternotomy: the breastbone is opened lengthwise for good access to the heart and vessels. In contrast, MICS-CABG uses a smaller, lateral incision in the chest, keeping the sternum intact.
USZ Points to Growing Experience
The University Hospital Zurich (USZ) states it was the first cardiac surgery center in Switzerland to establish MICS-CABG for treating multi-vessel disease. The hospital also reports that it now performs about one-third of its isolated bypass surgeries minimally invasively, some with robot-assisted steps.
These figures come from the USZ itself. There is no publicly available, independent nationwide survey confirming the claimed pioneering role or comparison with all other Swiss cardiac surgery centers. The statement should therefore be understood as the hospital's self-representation and not as an independently verified ranking.
The abbreviation also requires clarification: MICS-CABG stands for minimally invasive cardiac surgery coronary artery bypass grafting in English medical terminology. It is not equivalent to all minimally invasive heart operations. Technical implementation, the number of bypasses, and the use of a heart-lung machine may vary depending on the center, anatomy, and surgical strategy.
Potential Benefits – Not Equal for All
Avoiding a full sternum division can offer advantages for suitable patients: the chest wound is smaller, and the burden of sternal healing is eliminated. This can promote early mobilization and subjectively perceived physical recovery.
A randomized study published in 2026, involving 170 patients with multi-vessel disease, compared MICS-CABG with conventional sternotomy. One month after surgery, the MICS-CABG group reported slightly better physical recovery on average. Within twelve months, this study showed no evidence of a safety disadvantage. However, the study was relatively small, predominantly involved men, and was conducted at experienced centers. Conclusions about very long-term results or general superiority cannot be drawn from it.
A systematic review from 2024, comprising 26 studies and a total of 7556 cases, also concluded that MICS-CABG appears feasible in carefully selected individuals with multi-vessel disease. At the same time, the authors emphasize the lack of larger randomized studies with longer follow-up. Existing evidence largely relies on observational studies from specialized centers.
A Demanding Operation with a Learning Curve
Minimally invasive does not automatically mean low-risk or generally superior. Access through a small incision complicates visibility and vessel handling. Professional publications point to a pronounced learning curve; therefore, the entire team's experience, suitable infrastructure, and careful case selection are crucial.
European guidelines on revascularization also describe minimally invasive coronary procedures as a possible alternative to sternotomy, especially in selected situations. While they refer to benefits in early quality of life and length of stay, they also note that rib spreading can cause pain. For more complex multi-vessel diseases, a joint assessment by cardiology and cardiac surgery also plays an important role.
Which treatment is suitable in individual cases depends on factors such as the location and number of vessel narrowings, heart function, comorbidities, previous interventions, and technical feasibility. This article does not replace medical consultation or treatment decisions.
What Can Be Said About the USZ
With its high proportion of minimally invasive procedures, the USZ demonstrates that it has systematically integrated this approach into its cardiac surgery offerings. However, this does not imply that the method is suitable for all bypass patients, nor that it is generally superior to conventional surgery in terms of long-term clinical outcomes.
The most factual classification is therefore: MICS-CABG is an established but technically demanding option for selected cases. Recent randomized evidence suggests benefits for early recovery in experienced centers. Publicly available independent evidence is lacking for claims of long-term superiority, applicability to all patient groups, or the USZ's asserted pioneering role in Switzerland.
Sources
- University Hospital Zurich: Minimally Invasive Bypass Surgeries (Hospital information on offerings, proportion, and classification)
- MIST Study: Multivessel coronary artery bypass grafting via small thoracotomy versus sternotomy, randomized study, 2026
- Systematic Review on MICS-CABG for Multi-vessel Disease, 2024
- ESC/EACTS Guidelines on Myocardial Revascularization, section on minimally invasive and hybrid procedures
- Specialist Article on the Introduction and Learning Curve of MICS-CABG, 2019
