CARDIOVASCULAR JOURNAL OF AFRICA • Volume 35, No 3, September – October 2024 AFRICA 145 needed a second operation on the aortic valve. This may have been due to the neo-sinuses that were created and the low volume of leaflet repairs needed in our patients. In the past, various methods have been described for the selection of graft size in the David procedure. The original method is based on the Feindel–David formula.6 Later, David himself described using grafts that were approximately twice the mean heights of the valve cusps for the David V procedure.23 In addition to these graft-selection criteria, there are many methods described in the literature. The majority of currently available complex formulae for graft sizing are based on relative dimensions of the normal aortic root.24 However, it should not be forgotten that there is no normal aortic root anatomy, especially in patients with large aneurysms or BAV. Therefore, choosing the graft size based on fixed normal aortic valve sizes only, such as annular diameter, may be misleading.13 The main purpose of sizing is to obtain an appropriate aortic cusp coaptation site and length, while at the same time avoiding prolapse. We did not use these formulae to determine proximal graft size in this series. We measured the imaginary STJ distance at which the aortic valves were coapted and there was no prolapse with a valve-measuring instrument. We then determined the graft size by adding an average of 4–7 mm to this value. This method is similar to the method used by Khachatryan et al.13 The percentage of a second operation for AI would be slightly higher in a case series with larger numbers of BAV and aortic leaflet repair. In a study by Mastrobuoni et al., regarding re-operation on the aortic valve, they reported freedom from re-operation of more than 90% at 10 years.25 David and colleagues reported freedom from re-operation of more than 95% at 10 years.26 The reason for the disparity in these two studies is explained by the different percentage of patients with BAV and the need for additional valve repair. Besides, in the first study, it was observed that more additional leaflet repair was also needed in other patients without BAV.25 Another problem in patients with BAV is the possibility of developing aortic stenosis after the operation during follow up. Also, in patients with BAV accompanied by a genetic syndrome, the risk of developing aortic dissection after the operation should not be forgotten.27,28 We have not observed aortic stenosis or aortic dissection in our patients with BAV during follow up. It has been reported that when BAV involvement is present, surgeons are skeptical and favour conventional techniques.17 However, pioneers point out that BAV involvement is not a contra-indication for V-SARR techniques and recommend re-implantation techniques if indicated.29 Furthermore, longterm results of patients with bicuspid and tricuspid aortic valves who underwent re-implantation techniques were similar.8 In our case series, five patients had BAV. In their follow up, none of these patients died and no more than ≥ 2+ AI was detected. An aortic valve conduit graft may be an option in the case of early AI development in patients who had V-SARR techniques implemented.9 A similar pathology only occured in one of our patients. We performed a mechanical AVR into the graft of the David V and the patient was discharged without any complications. We therefore believe that, in similar situations, the application of AVR into the graft may be simple and sufficient. In recent studies, the operative mortality rate of V-SARR techniques was below 2% in centres with experienced surgeons.8,17,29-32 However with these techniques becoming more popular, in-hospital mortality rates increased up to 6% in some European centres.33 The causes of mortality in these cases were mostly cerebrovascular events, low cardiac output, multiorgan failure, and less frequently, bleeding.9,29,30,33-36 In our series, in-hospital mortality occurred in two (4.2%) patients. In some publications, the mortality rate was higher in aortic dissection or emergency operations,33,34,37-39 however, in our series, five patients (10.4%) were operated on urgently. There were no mortalities in any of these patients who were operated on for ATAAD. Some authors suggest that V-SARR surgeries should be performed only in centres where the 10-year freedom from valve re-operation or mortality exceeds 90%.8 In our series, the mean follow-up period was 5.7 ± 3.1 (0.2–9.8) years. Six patients (12.5%) died. One (2.1%) patient was re-operated on because of a severe AI that ocurred in the early postoperative period. A stage 3+ AI was present in only one patient in the first year of surgery. This patient had primary hypertension and the patient’s angiotensin-converting enzyme inhibitor medication was increased gradually to the maximum dosage. This patient was under follow up for five years and the patient’s AI grade was 2+ at the last TTE check up. At the end of our follow up, none of our patients had > grade 2+ AI on TTE. Thirty-six (75%) patients had normal aortic valve function or grade 1+ AI and five (10.4%) had moderate AI. In other words, freedom from moderate to severe residual AI was 89.6% (43 patients) at 10 years. In an article written by David in 2010, freedom frommoderate to severe aortic insufficiency at 12 years was reported as 91.0 ± 3.8% after re-implantation.18 In a prospective study of 83 patients, by Coselli et al. on aortic root aneursym, it was reported that the grade of AI would remain stable postoperatively.12 Similarly, no progression of AI was observed in our case series and ≤ grade 2+ AI was well tolerated in these patients unless a deep bradycardia occurred.7 We agree with this opinion and believe that, especially in older patients, β-blocker treatment should be initiated after a good evaluation. Study limitations This study has several important limitations, including those inherent in retrospective reviews. The mean follow-up period in this study was 5.7 ± 3.1 years, so the longer-term durability of the modified David V technique cannot be inferred from our findings. Another limitation is that the study had a small sample size. Conclusions In our experience, this study shows that the modified David V technique can be effective, with excellent long-term durability, it protects the re-implanted native aortic valve from a second operation, and it offers a better quality of life. Even so, follow up remains necessary to evaluate the long-term durability of V-SARR. We also found that this technique could safely be applied in BAV and ATADD patients without leaflet deformity. In our opinion, the technique is an important option that precludes complications arising from mechanical/biological valves of the composite graft. A large number of studies are nevertheless needed to prove the effectiveness of the technique and promote more widespread use.
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