A water-test is performed to assess the coaptation of the reimplanted
native AV. Additional AV leaflet repair is performed if needed. The
coronary buttons are reinserted using a continuous 5-0 polypropylene
suture. Finally, the valve and hemostasis are tested by pressurizing the
aortic root with cardioplegia. Meticulous hemostasis is particularly
important factor during minimally invasive David procedure.
The distal anastomosis is performed, and the aortic clamp removed after
de-airing. AV function is assessed by intraoperative TOE. Patients
require long-life antiplatelet therapy with aspirin. Repeat
transthoracic echocardiography is recommended before discharge.
Postoperative management and outcomes
Patients undergoing minimally invasive David procedure require special
postoperative management in order to achieve faster recovery as expected
after minimally invasive surgery. Immediate perioperative anesthetic
management individualized to each patient and early extubation represent
important adjuncts in the early postoperative care of these patients.
Complete rewarming of the patient is achieved while in the operating
room. In the event of significant bleeding, re-exploration should be
accomplished through the same incision.
Recent studies reported postoperative clinical outcomes with minimally
invasive David procedure comparable to the conventional
technique.10-16 Postoperative outcomes and
characteristics of included studies are demonstrated in a Table 1.
30-day mortality was reported between 0% and 3.3%, although all the
published series had a sample size of less than 100
patients.10-16 Furthermore, selection of patients
might have positively influenced outcomes as minimal access was
performed in elective patients with noncalcified aortic valves. Notably,
Marfan syndrome was reported in 3.9-18.8% of patients and they
represent a subgroup of patients that could benefit most of minimal
access technique.10-16
Aortic cross clamp and CPB time were somewhat longer than in standard
David procedure and ranged from 111 to 168.5 minutes and from 139 to
199.5 minutes, respectively.10-16 However, it seems
that this has not negatively influenced postoperative clinical outcomes.
Several studies reported decreased requirements for blood products,
relatively shorter ICU length of stay (1.1-3 days) and low 30-day stroke
rate (0-3.3%). Despite the fact that most centers emphasized importance
of meticulous hemostasis, re-exploration for bleeding was reported up to
9% in some of the studies.10,11,13
In summary, our review of available literature on the topic of minimally
invasive David procedure demonstrated that this approach could
facilitate recovery of selected elective patients with isolated aortic
root aneurysm along with similar early postoperative outcomes to
conventional surgery. However, there are many potential pitfalls in
minimally invasive David procedure and recent studies highlighted
challenges of the learning curve. Sufficient experience at centers with
adequate case volumes in both conventional aortic root surgery and
minimal access AVR are necessary before progressing to the next step to
avoid potential vulnerability and performance obstacles.
Ljubljana experience
At the University Hospital Center Ljubljana (Slovenia, EU), 16 patients (12 male) with isolated aortic root aneurysm were selected for minimally invasive David procedure over a 4-year period (Figure 1). No Ethics Committee approval was required given that this analysis was retrospective and anonymized. All patients were consented for the surgery and use of their anonymized data for future research and publications.
Concomitant aortic valve repair was performed in 8 out of 16 (50%) patients and coronary artery bypass graft (saphenous venous graft to right coronary artery) in one patient. In most cases, straight 30-32 mm Dacron graft (Gelweave) was used. Technique was also modified by performing wrapping of distal anastomosis in 10 out of 16 patients as, in our experience, it was helpful in achieving better hemostasis. No conversion to full sternotomy or re-exploration due to bleeding was observed. 30-day postoperative mortality and stroke were 0%.