Abstract
Background: Valve-sparing aortic root replacement such as the re-implantation (David) procedure is becoming increasingly popular. Despite the fact that the procedure is technically more complex, long-term studies demonstrated that excellent clinical outcomes in selected patients with durable repair are achievable. Benefits of minimal access cardiac surgery have stimulated enthusiasm in the use of this approach for valve-sparing aortic root replacement.
Methods: We have reviewed available literature on the topic of valve-sparing aortic root replacement (David procedure) via minimally invasive approach through upper hemisternotomy in an attempt to assess current trends and to recognize potential advantages of this technique. Patient selection and preoperative work-up play important role in performing minimally invasive David procedure safely. Surgical technique is similar to the standard David procedure, with several exceptions, and is performed via upper hemisternotomy.
Results and Conclusion: Evidence from non-randomized observational and comparative studies demonstrated excellent clinical outcomes of minimally invasive David procedure in selected patients with comparable perioperative mortality to the conventional technique. To date, elective David procedure with a minimal access technique has been performed in low- and intermediate-risk patients. We believe that minimally invasive David procedure could be particularly useful in young patients (Marfan syndrome, bicuspid AV) as it allows faster recovery with improved cosmesis. A decision to perform minimally invasive David procedure should be individualized to each patient and based on the experience of the team. Further large prospective randomized studies with long-term follow-up are still needed to confirm durability of minimal access technique.
Keywords: valve-sparing aortic root replacement, David procedure, minimally invasive cardiac surgery, aortic root aneurysm, hemisternotomy.
Introduction
For several decades, the composite replacement with a valved conduit, as first described by Bentall and De Bono, has been a gold standard for the treatment of a combined pathology of the ascending aorta and the aortic valve (AV).1 Valve-sparing aortic root replacement such as the re-implantation (David) procedure is becoming increasingly popular, particularly in patients with normal AV function.2 One of the major benefits of this technique is that it avoids the disadvantage of composite root replacement including the need for life-long anticoagulation as in mechanical valve conduits or structural valve degeneration with the need of reoperation as in tissue valve conduits.3,4. Despite the fact that the procedure is technically more complex, long-term studies demonstrated that excellent clinical outcomes in selected patients are achievable even over the 25-year follow-up period.3,5,6 It is evident that excellent surgical outcomes have been a combination of careful patient selection and meticulous surgical technique.5 As outlined by David and colleagues, AV function slowly deteriorates with the cumulative risk of developing moderate or severe aortic regurgitation (AR) in up to 10.2% of patients after 20 years, while the cumulative proportion of AV reoperations was reported to be 6.0% (95% C.I. 2.8%, 12.9%) after 20 years.5 Similarly, Mokashi and colleagues in a cohort of 92 patients reported the freedom from reoperation after the David procedure for tricuspid AV of 98% at 8 years,  whereas it was 77% for bicuspid AV .7 However, despite some studies have raised concerns regarding the lower durability of the David procedure, Leontyev and colleagues demonstrated in their propensity-matched analysis that the David procedure is preferable to the Bentall procedure in patients with appropriate pathoanatomy.8 The authors reported similar survival rates and freedom from reoperation after 10 years with lower risk of postoperative bleeding and avoidance of long-term complications related to the use of prosthetic valve.8
Benefits of minimally invasive cardiac surgery have stimulated enthusiasm in the use of minimally invasive access for both Bentall procedure and valve-sparing aortic root replacement.9-16 Since the first report of minimally invasive aortic valve replacement (AVR) in 1993, minimally invasive access has been associated with comparable operative mortality, less bleeding and reduced intensive care and hospital stay when compared to the conventional sternotomy.11,12,17-20 Furthermore, faster recovery, less pain and better cosmesis have been reported in several clinical studies.21-23
In this article, we have reviewed all the available literature on the topic of valve-sparing aortic root replacement (David procedure) via minimally invasive access through upper hemisternotomy in an attempt to assess current trends and to recognize potential advantages of this technique. We believe this is the first comprehensive review article to discuss minimally invasive valve-sparing aortic root replacement (David procedure).