Trileaflet pulmonary valve reconstruction with the Ozaki technique in an adult patient of tetralogy of Fallot with absent pulmonary valve

Abstract

Pulmonary valve interventions are one of the most common cardiac interventions that are being performed in patients with a wide variety of congenital heart diseases, more so in adults with congenital heart disease. Despite the introduction of various different reconstructive techniques and conduits, the ideal option still remains elusive. Lack of growth and re-operation for conduit replacement remains an Achilles heel in such conduits. So, surgeons have constantly tried to evolve surgical techniques that would obviate their use and allow age-related growth. The Ozaki procedure has proven to be technically reproducible and have excellent mid-term results in the aortic position in adults. Extending the same principle for reconstruction of the pulmonary valve can prove to be a reasonable alternative.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-022-01469-1.

Introduction

In children with complicated congenital heart disease, specifically those with the right ventricular outflow tract obstruction, right ventricle (RV) to pulmonary artery (PA) continuity reconstruction has become one of the most common surgical procedures. Conventional options for pulmonary valve replacement (PVR) include bioprosthetic valves, homografts, and mechanical valves [1]. Individual institutions in valve banks are largely involved in harvestation and preparation of homografts. Availability of homografts is determined by the supply of cadaver hearts and is generally limited. However, they are the preferred conduit of choice because of their longevity and superior handling characteristics. Most non-homograft conduits are commercially available in most parts of the world in a wide range of sizes. Mechanical valves are readily available but require permanent anti-coagulation and there is an inherent risk of thrombus formation owing to the low-pressure circulation. Structural valve deterioration, mainly in the form of leaflet calcification, is a major concern surrounding the durability of bioprosthetic valves in the pulmonary position. Thus, surgeons often resort to handmade conduits, made in the operating room from bovine or autologous pericardium, polytetrafluoroethylene (PTFE), or dacron [2]; however, the longevity of these conduits is uncertain with high reintervention rates. Amidst all these options, the pulmonary valve reconstruction using Ozaki’s principles is an excellent alternative as it has proved to have exceptional mid-term results, when used in the aortic position [3]. Here, we present the case of a 25-year-old lady with a diagnosis of tetralogy of Fallot (TOF), who underwent a successful intracardiac repair with pulmonary valve reconstruction, where three leaflets were reconstructed from autologous pericardium using Ozaki’s principles. There is no literature about the reconstruction of a trileaflet pulmonary valve using the Ozaki principles in patients with TOF, making it one of the rare cases. (Literature search was done on “PubMed” using the MeSH terms “pulmonary valve” and “tetralogy of fallot” and “autologous pericardium” and “glutaraldehyde.”).

Case report

A 25-year-old lady presented to the outpatient department with complaints of dyspnea on exertion and cyanosis since birth. On physical examination, there was a single second heart sound with an end diastolic murmur in the pulmonary area. Transthoracic echocardiography was suggestive of TOF with absent pulmonary valve (Fig. 1A, B). The branch pulmonary arteries were hugely dilated with the right pulmonary artery (RPA) and left pulmonary artery (LPA) measuring 35 and 37 mm respectively. After a detailed discussion in the Heart Team, it was decided to proceed ahead with a definitive intracardiac repair along with pulmonary valve neocuspidization using the Ozaki technique. After a median sternotomy, a large pericardial patch was harvested and treated with 0.6% glutaraldehyde for 6 min. Cardiopulmonary bypass was instituted and the heart was arrested using Del Nido cardioplegia. The infundibular muscle resection was done through the right atrium and infundibulotomy incision. The outlet ventricular septal defect was closed using a PTFE patch (®Impra Bard) using interrupted pledgeted 5–0 polypropylene sutures. Main pulmonary artery was incised longitudinally. The incision was carried proximally across the pulmonary annulus just enough to achieve the pre-determined diameter of right ventricular outflow and the pulmonary annulus (according to the Rowlatt charts). Distally, the incision was carried onto the left pulmonary artery for a sufficient distance. The right pulmonary artery was incised separately with its incision meeting the incision in the main pulmonary artery. Excess tissue of the main pulmonary (MPA), LPA, and RPA was excised. Bovine pericardium, fashioned in a diamond shape, was sutured across the pulmonary annulus in order to form a tube of a fairly uniform diameter based on the predetermined diameter. The bovine pericardial patch was incised in the center to meet the incision in the MPA.

Fig. 1.

Pre-operative echocardiography: A trans-thoracic parasternal short axis view showing significant pulmonary regurgitation and pulmonary stenosis on color Doppler with a pulmonary annulus measuring 18.7 mm; B trans-esophageal parasternal long-axis view showing the RV outflow with severe pulmonary regurgitation and a gradient of 81 mmHg across the pulmonary valve. Post-operative echocardiogram: C upper esophageal aortic arch short axis view showing coaptation length of 26.7 mm, following pulmonary valve reconstruction; D trans-gastric view RV basal view showing a maximum gradient of 14 mmHg and a mean gradient of 5 mmHg (RV, right ventricle)

The template of size equal to one-third the diameter of the “neo MPA” (FF’ in the Fig. 2) was chosen and three leaflets (23 mm each) were carved out of the autologous pericardial patch (Fig. 3). These were sewn into MPA using 5/0 polypropylene suture as shown in Fig. 2. Suturing was begun at the nadir point (marked A, B, and C in the Fig. 2); the nadir point was marked at a distance of 80% of the template size down from the midpoint of the line joining the two commissures of the leaflet (marked D, E, F, and F’ in the Fig. 2). The PAs were sutured together making sure point F joins F’ creating the third commissure. In the immediate postoperative echocardiography, there was mild pulmonary regurgitation, right ventricular outflow tract (RVOT) peak gradient of 15 mmHg, and a good coaptation height of 26 mm between the 3 cusps (Fig. 1C, D). In the immediate postoperative period, the vasoactive ionotropic support score was 18 and the patient was extubated after 18 h. The intensive care unit (ICU) stay and hospital stay were 5 days and 8 days respectively. The patient is currently doing well in the post-operative period.

Fig. 2.

Diagrammatic representation of pulmonary artery after sizing and implantation of bovine pericardial patch and incising the patch in the midline to meet the incision in the MPA extending into LPA and meeting the incision in RPA. MPA, main pulmonary artery; LPA, left pulmonary artery; RPA, right pulmonary artery

Fig. 3.

Intra-operative images: A surface anatomy of the heart with mildly dilated MPA (black arrow, pulmonary valve level), B RVOT view through the MPA with the rudimentary pulmonary valve cusp (*) with the hypertrophied muscle (black arrow), C pulmonary valve (black arrow) view after reconstruction with autologous pericardium. MPA, main pulmonary artery; RVOT, right ventricular outflow tract

Discussion

Tetralogy of Fallot represents approximately 7–10% of congenital heart diseases with its prevalence in adults being 1 in 4000 people [4]. Survival into adulthood is more common in developing countries. Life expectancy in these patients is shorter than that in the population at large, and among the clinically important complications that can affect the adults with repaired TOF, pulmonary regurgitation (PR) is most common and is a typical situation that requires PVR. Severe PR can cause RV volume overload leading to RV dilation and dysfunction, arrhythmias, exercise intolerance, and possibly sudden death. Despite the introduction of different RV to PA reconstructive techniques and conduits, the ideal option is yet to be developed. Over the past few years, surgeons all over the world have resorted to constructing such conduits in the operating room itself, mainly because of supply constraints, cost, and issues with long-term durability. Various materials like PTFE, dacron, and pericardium have been used for this purpose. Recent developments in the PTFE pulmonary valves have provided a promising alternative. In addition to the trileaflet design, PTFE valves with monoleaflet and bileaflet designs have also been introduced to adapt to the smaller pulmonary annulus, especially in pediatric patients. Among these, the clinical and satisfactory outcomes of PTFE prosthesis with bileaflet design have been widely reported, though the long-term results are still awaited.

Reconstruction of the pulmonary valve in a trileaflet model using the Ozaki principles has, however, got its own advantages [5]. It has successfully been applied in the aortic position with excellent outcomes. Since the Ozaki technique does not fix the pulmonary annulus, the neo-pulmonary annulus grows with time and decreases mechanical stress onto the commissures and annulus. A generous coaptation height should allow to retain a satisfactory coaptation surface as the annulus grows and the coaptation height reduces. The autologous pericardium used is non-antigenic and in a recent study by Myers et al., autologous pericardium was found to have a better durability than bovine pericardium [6].

Conclusion

A sizeable proportion of congenital heart defects have a component of right ventricular outflow tract abnormality. The conduit that possesses all of the favorable attributes has not yet been developed. The Ozaki technique allows natural pulmonary root expansion with maximal effective orifice preservation in systole and has been successfully applied to a wide spectrum of aortic valve diseases in adult patients.

Supplementary Information

Below is the link to the electronic supplementary material.

Author contribution

HS—Manuscript writing.

VH—Manuscript writing.

TS—Manuscript editing.

HA—Manuscript editing.

VB—Manuscript writing.

Funding

None.

Availability of data and material

Yes.

Code availability

Not applicable.

Declarations

Ethical approval

According to our institutional protocol, ethical approval is not required for a case report.

Informed consent

Informed consent was taken from the patient and her parents.

Statement of human and animal rights

No animals or humans were used nor harmed for this research manuscript.

Conflict of interest

The authors declare no competing interests.