**5.3 Early complications, mortality, and outcomes**

Early postoperative complications and outcomes are highlighted in **Table 6**. There was no in-hospital mortality, postoperative myocardial infarction, stroke, renal failure, wound complications, and bleeding required resternotomy. Two patients who underwent redo surgery required permanent pacemaker implantation due to severe tricuspid annulus damage. In one patient with fungal prosthetic endocarditis, a parahomograft leak was diagnosed but did not require reoperation. This

*Contemporary Approach with Mitral Valve Allograft in the Treatment of Tricuspid Valve… DOI: http://dx.doi.org/10.5772/intechopen.111687*


#### **Table 5.**

*Etiology of tricuspid valve disease and type of procedure.*

complication was considered as an early homograft dysfunction, nevertheless, it did not prevent a patient from complete endocarditis recovery and successful discharge from the hospital. In the follow-up period, two patients experienced a relapse of infective endocarditis in 3 and 6 months postoperatively with moderate homograft dysfunction, nevertheless, such dysfunction was tolerated well and patients recovered from infection. Patients have not been scheduled for redo operation yet. One patient had the second episode of endocarditis 1 year postoperatively and the affected valve was the aortic valve, whereas the mitral homograft was competent. There was no late mortality, or permanent pacemaker implantation in the follow-up period.

### **6. Discussion**

Tricuspid valve operations continue to be among the most infrequently performed cardiac surgical procedures. An analysis of the Society of Thoracic Surgeons database reported only approximately 5000 tricuspid valve procedures performed per year, and most of these procedures were repairs [11].

TVR is therefore even less common, especially when it is performed in isolation [40]. It is not surprising that institutional analyses often evaluate multiple decades of operative practice to analyze fewer than 100 TVR [41]. Despite the fact that TVR has not seemed to be complicated in terms of surgical technique, operative mortality is still reported to be high, moreover, there are quite variable outcomes among studies. Leviner and colleagues reported 5.7% 30-days mortality and 14.3% 1-year mortality for the whole cohort, with a slightly higher, but not statistically significant, mortality risk for those patients who underwent isolated TVR [41]. According to Cheng Z., early mortality after TVR was 0–23.46% for biological valves and 3.03–40% for


*Me [Q1-Q3] – median and interquartile range; M ± SD – mean and standard deviation; PASP – pulmonary artery systolic pressure; VC – vena contracta on mitral homograft; Peak PG – peak transhomograft diastolic pressure gradient; Mean PG – mean transhomograft diastolic pressure gradient.*

#### **Table 6.**

*Early complications, mortality, and outcomes.*

mechanical valves respectively, while the reoperation rate of biological valves was 1.94–22% while mechanical prostheses were 0.83–19.57% [6].

Regarding other significant postoperative complications, bleeding required resternotomy, and permanent pacemaker implantation remain to be unacceptably high—25.81 and 18.18% respectively, even in current reports devoted to isolated TVR with either biological or mechanical prosthesis [41]. In our study, zero mortality, and low postoperative complication rates were achieved. Having been proposed for TVR, mechanical and biological valves did not prove their complication-free profile, nevertheless, these valve substitutes are still recommended.

Among those studies that gave insight into feasibility of allografts in tricuspid surgery, there were a lot of inconclusive results in terms of surgical technique, and earlyand long-term results. This fact could be explained by limited experience, homograft shortage, and low accessibility, as well as more complex surgical techniques. By the way, available data represent excellent initial results with allograft valves in the treatment of tricuspid valve disease [9, 31, 34]. Comparative studies with commonly used biological and mechanical prosthesis have not been conducted which increase the importance of our study by providing the relevant experience with mitral homografts in the tricuspid position. Obvious beneficial effects, derived from using homografts, could be a low reinfection rate, better hemodynamic performance, and no need for anticoagulation therapy, further valve repair options in case of endocarditis relapse or annular dilatation [42]. Not only does the homograft valve in tricuspid position allow further open valve repair, but also provides some opportunities for transcatheter TVR [43].

#### *Contemporary Approach with Mitral Valve Allograft in the Treatment of Tricuspid Valve… DOI: http://dx.doi.org/10.5772/intechopen.111687*

When it comes to possible drawbacks of using homografts in tricuspid surgery, such possible disadvantages are brought to mind—unpredictable long-term durability and variety of preserving methods for homograft tissue which therefore might rise or sustain existing reluctance to homograft surgery. Banking on the long-term durability of homograft tissue, relevant scientific data will be available provided a larger surgical experience appears. In accordance with Campelos P., long-term durability could generally be achieved for mitral homograft, but the data is confined to one report [30]. Recent advances in decellularized allografts for aortic valve surgery only encourage wider utilizing homograft valves in cardiac surgery [44]. The type of conduit is considered to be one of the most important factors in long-term durability, for example, the survival rate of the pulmonary conduit is higher than that of aortic conduit [45, 46]. Baltivala et al. found that the graft survival rate of patients with a history of transplantation was worse than that of other patients [47]. The relationship between bioactivity and durability of homograft valved conduit is still controversial. Fibroblasts living in the graft can reshape and reconstruct collagen structure and extracellular matrix, thus enhancing durability [48]. However, these unevenly distributed fibroblasts may have phenotypic changes and abnormal biological behavior due to immune responses or environmental changes. Decellularized valved conduits demonstrate almost complete removal of cells and cellular components by histological and immunocytochemical analysis without corresponding changes in biomechanics *in vitro* [49]. Studies compared rejection rate, immune response, and cellular activity in atrioventricular homografts vs. aortic and pulmonary homografts have not been published yet due to the complexity of comparison and different hemodynamic patterns, though it should be one of the future directions in homograft tissue science, implicated to cardio-vascular surgery.
