One and half ventricle repair: rationale, indications, and results

Generation of an induced pluripotent stem cell line (NCHi016-A) from a 5-year-old female with pulmonary atresia with intact ventricular septum and one-and-half ventricle palliation

Pulmonary atresia with intact ventricular septum (PA-IVS) is a rare congenital heart defect characterized by underdeveloped pulmonary valve and right ventricular hypoplasia. Neonates undergoing surgery to open pulmonary valve have a range of post-surgical ventricular recovery: single-ventricle (1v) palliation, one-and-half ventricle (1.5v) palliation, and bi-ventricular (2v) repair. PA-IVS-1.5v typically requires surgical intervention to install cavopulmonary shunt and entails partial right ventricle recovery. NCHi016-A is an iPSC line derived from a 5-year-old female with PA-IVS-1.5v using Sendai Virus reprogramming. This iPSC line shows typical iPSC morphology, has normal karyotype, expresses pluripotency markers, and has potential to differentiate into three germ layers.

Borderline Ventricles: From Evaluation to Treatment

A heart with a borderline ventricle refers to a situation where there is uncertainty about whether the left or right underdeveloped ventricle can effectively support the systemic or pulmonary circulation with appropriate filling pressures and sufficient physiological reserve. Pediatric cardiologists often deal with congenital heart diseases (CHDs) associated with various degrees of hypoplasia of the left or right ventricles. To date, no specific guidelines exist, and surgical management may be extremely variable in different centers and sometimes even in the same center at different times. Thus, the choice between the single-ventricle or biventricular approach is always controversial. The aim of this review is to better define when "small is too small and large is large enough" in order to help clinicians make the decision that could potentially affect the patient's entire life.

Isolated hypoplastic right ventricle - a challenge in medical practice

Isolated right ventricle hypoplasia (IRVH) is a disease characterized by an underdeveloped right ventricle. It is a congenital heart disease than can associate heterogeneous structural defects and nonspecific clinical features, which can often present a challenging therapeutic management. In this article, there are presented diagnostic methods and treatment options for right ventricle hypoplasia (RVH) according to clinical features, patients age and associated structural heart defects. RVH has a different prognosis in accordance with the severity of the heart defects and the patient's age at which the diagnosis is established. Thus, isolated forms of RVH generally present mild structural and functional defects that can be associated with the onset of symptoms in adolescence or even in adulthood. In these cases, atrial septal defect closure with or without superior cavo-pulmonary anastomosis can be the only procedures needed to correct the hemodynamic abnormalities and relief the symptomatology. Patients with severe form of RVH associated with complex cardiac malformations and onset of the symptoms in the neonatal period require prompt intervention and necessitate palliative procedures. In the long term, these patients could need multiple reinterventions. The family physician should be aware of the cardiac origin of isolated symptoms or clinical signs, such as exertional dyspnea or clubbing fingers, and send the patient for pediatric cardiological evaluation.

Numerical Simulation of the Effect of Pulmonary Vascular Resistance on the Hemodynamics of Reoperation After Failure of One and a Half Ventricle Repair

OBJECTIVE

The one and a half ventricle repair (1.5VR) is a common clinical choice for patients with right heart dysfunction. Considering the influence of blood circulation failure and reoperation in urgent need, this essay aims to explore the hemodynamic effects of different pulmonary vascular resistance (PVR) values on reoperation after 1.5VR failure.

METHODS

The lumped parameter model (LPM) was used to simulate the reoperation, including the return biventricular repair (2VR), ligation of azygos vein (1.5VR') and return single ventricular repair (1.0VR). Firstly, the debugging parameters were used to simulate the hemodynamics of 2VR. Secondly, the value of PVR was changed from one to four times while the other parameters remained unchanged. Finally, 15 cardiac cycles were simulated and the 15th result was obtained. In this work, the left and right ventricular stroke work and their sum (Plv, Prv, Ptotal), the left and right ventricular ejection fraction (LVEF, RVEF), the mean Cardiac Output (mCO) and the mean pressure and flow-rate ratio of superior and inferior vena cava (mPsvc\mPivc and mQsvc\mQivc), respectively, were used to describe the hemodynamics of reoperation.

RESULTS

With the change of PVR from one to four times, the values of Plv, Prv, Ptotal, LVEF, and RVEF gradually decreased. The change rate of Plv, Ptotal and LVEF of 1.0VR were the largest in the three kinds of reoperation. The change rate of Prv of 1.5VR' was larger than that of 2VR, but it was the opposite for their EF change rate. The mCO of 2VR, 1.5VR', and 1.0VR decreased by 18.53%, 37.58%, and 48.07%, respectively. The mPsvc\mPivc of 1.5VR' increased from 3.76 to 6.77 and the mQsvc\mQivc decreased from 0.55 to 0.36, while the mPsvc\mPivc and mQsvc\mQivc of 2VR and 1.0VR remained 1 and 0.67, respectively. The peak value of the tricuspid flow-rate (Qti) waveform of 2VR and 1.5VR' changed from "E peak" to "A peak."

CONCLUSION

The numerical results demonstrate the highly reoperation-dependent hemodynamic consequences and their responses to variations in PVR. Comprehensive analysis of EF, mCO and ventricular stroke work indicates that PVR has a greater impact on 1.5VR' and 1.0VR. Therefore, we suggest that the selection strategy of reoperation should focus on PVR.