Reliability of intraoperative transesophageal echocardiography during Tetralogy of Fallot repair

Percutaneous pulmonary valve implantation with the Venus P-valve: clinical experience and early results

BACKGROUND

At present, the exclusion for percutaneous pulmonary valve implantation for free pulmonary regurgitation after tetralogy of Fallot repair includes an unfavourably large right ventricular outflow tract.

OBJECTIVE

To report feasibility and early experience with a recently developed transcatheter heart valve, Venus P-valveTM, implanted in six patients with severe pulmonary regurgitation with large right ventricular outflow tracts. Patients There were two female patients and four male patients. The median age of the patients was 18.5 years, and the mean body weight was 53.8 kg. All the patients were in NYHA class II and had severe pulmonary regurgitation after previous transannular patch repair of tetralogy of Fallot. The median time after the last surgical operation was 13.5 years.

RESULTS

The Venus P-valveTM was successfully implanted in all the patients with implanted valve diameters ranging from 24 to 32 mm. The mean fluoroscopy time was 29.8 minutes. None of the patients had significant outflow tract gradient or pulmonary regurgitation immediately after valve implantation. Only one patient had unexpected mild proximal valve migration to the right ventricular body during withdrawal of the delivery system. It caused mild paravalvar leak and significant tricuspid regurgitation. At 6 months follow-up, the median of right ventricular end-diastolic volume indices decreased from 146 to 108 ml/m2 (p-value=0.046). The Doppler systolic peak gradient across the valve ranged from 4 to 40 mmHg, and there was no evidence of stent fracture on fluoroscopy or structural valve failure.

CONCLUSION

The Venus P-valveTM can be implanted successfully and effectively in patients with severe pulmonary regurgitation and a large right ventricular outflow tract. The early results with this valve are encouraging.

One-year follow-up of the Melody transcatheter pulmonary valve multicenter post-approval study

OBJECTIVES

This study sought to confirm that the short-term hemodynamic effectiveness of the Melody transcatheter pulmonary valve (TPV) (Medtronic, Inc., Minneapolis, Minnesota) achieved by real-world providers is equivalent to the historical results established in the initial 5-center Investigational Device Exemption trial.

BACKGROUND

TPV replacement has been used to treat right ventricular outflow tract (RVOT) conduit dysfunction for >10 years. The Melody TPV received U.S. Food and Drug Administration approval in 2010 as a Humanitarian Use Device.

METHODS

Patients with dysfunctional RVOT conduits were entered in this prospective, nonrandomized study at 10 centers. The primary endpoint was acceptable hemodynamic function at 6 months post-implantation, defined as a composite of RVOT echocardiographic mean gradient ≤30 mm Hg, pulmonary regurgitation less than moderate as measured by echocardiography, and freedom from conduit reintervention and reoperation.

RESULTS

Cardiac catheterization was performed in 120 patients for potential implantation of the Melody TPV; of these, 100 patients were implanted, with a 98.0% procedural success rate. There were no procedure-related deaths. Acceptable hemodynamic function at 6 months was achieved in 96.7% of patients with evaluable data (87.9% of the entire implanted cohort), with results maintained through 1 year. No patient had moderate or severe pulmonary regurgitation after implantation. No patient required catheter reintervention in the first year after implantation, and 2 patients required reoperation for conduit replacement. The rate of freedom from TPV dysfunction was 96.9% at 1 year.

CONCLUSIONS

This first prospective, real-world experience with the Melody TPV in the United States demonstrates continued high procedural success, excellent short-term TPV function, and low reintervention and reoperation rates at 1 year. (Melody Transcatheter Pulmonary Valve Post-Approval Study; NCT01186692).

The role of transesophageal echocardiography during surgery for patients with tetralogy of Fallot

Routine use of intraoperative transesophageal echocardiography (TEE) is a safe monitoring and diagnostic method during pediatric congenital cardiac surgery. However, the question of whether intraoperative TEE is accurate and cost effective for patients with tetralogy of Fallot (TOF) has not been raised. This study aimed to analyze the cost-benefit of routine TEE during the repair of TOF. The medical records, including TEE results, for patients who underwent correction of TOF between January 1997 and June 2007 were reviewed and retrospectively analyzed. Intraoperative TEE was performed for 340 patients (85 %). Residual problems were detected in 17.9 % (61/340), and a return to bypass was needed for 10 % (34/340) of the patients. The degree of agreement between the intraoperative TEE and early postoperative transthoracic echocardiography (TTE) was relatively high. Surgeons with less surgical experience more frequently used intraoperative TEE (p = 0.007) and performed repeat bypass surgery at a higher rate (p = 0.00). Even relatively unskilled surgeons might be able to achieve surgical outcomes similar to those of experienced surgeons using intraoperative TEE. By avoiding late surgical revision, the possible cost savings were estimated to be 1,726,000 Korean won (US$1,489) per TEE examination. Intraoperative TEE can be used as a tool for surgeons in making decisions in the operating room. In addition, intraoperative TEE decreased the frequency of reoperations and postoperative interventions. The results of this study demonstrate that routine intraoperative TEE during repair of TOF was both clinically beneficial and cost effective.

Early versus late functional outcome after successful percutaneous pulmonary valve implantation: are the acute effects of altered right ventricular loading all we can expect?

OBJECTIVES

The purpose of this study was to assess the potential of late positive functional remodeling after percutaneous pulmonary valve implantation (PPVI) in right ventricular outflow tract dysfunction.

BACKGROUND

PPVI has been shown to impact acutely on biventricular function and exercise performance, but the potential for further late functional remodeling remains unknown.

METHODS

Sixty-five patients with sustained hemodynamic effects of PPVI at 1 year were included. Patients were divided into 2 subgroups based on pre-procedural predominant pulmonary stenosis (PS) (n = 35) or predominant pulmonary regurgitation (PR) (n = 30). Data from magnetic resonance imaging and cardiopulmonary exercise testing were compared at 3 time points: before PPVI, within 1 month (early) and at 12 months (late) after PPVI.

RESULTS

There was a significant decrease in right ventricle end-diastolic volume early after PPVI in both subgroups of patients. Right ventricle ejection fraction improved early only in the PS group (51 ± 11% vs. 58 ± 11% and 51 ± 12% vs. 50 ± 11%, p < 0.001 for PS, p = 0.13 for PR). Late after intervention, there were no further changes in magnetic resonance parameters in either group (right ventricle ejection fraction, 58 ± 11% in the PS group and 52 ± 11% in the PR group, p = 1.00 and p = 0.13, respectively). In the PS group at cardiopulmonary exercise testing, there was a significant improvement in peak oxygen uptake early (24 ± 8 ml/kg/min vs. 27 ± 9 ml/kg/min, p = 0.008), with no further significant change late (27 ± 9 ml/kg/min, p = 1.00). In the PR group, no significant changes in peak oxygen uptake from early to late could be demonstrated (25 ± 8 ml/kg/min vs. 25 ± 8 ml/kg/min vs. 26 ± 9 ml/kg/min, p = 0.48).

CONCLUSIONS

In patients with a sustained hemodynamic result 1 year after PPVI, a prolonged phase of maintained cardiac function is observed. However, there is no evidence for further positive functional remodeling beyond the acute effects of PPVI.

Transcatheter pulmonary valve implantation using the Edwards SAPIEN transcatheter heart valve

BACKGROUND

Conduits placed in the right ventricular outflow tract (RVOT) have limited longevity which often requires increasingly complex reoperations. Transcatheter pulmonary valve implantation improves conduit hemodynamics through a minimally invasive approach. We present data for 7 patients treated with the Edwards SAPIEN transcatheter heart valve (THV).

PATIENTS

Patients' ranged in age from 16 to 52 years, one was female, and all had NYHA class II-III symptoms. Patients had pulmonary homografts that had been placed 2-25 years earlier during the Ross procedure (n = 4), repaired double outlet right ventricle with situs inversus (n = 1), or Rastelli repair for D-TGA, pulmonary atresia, and ventricular septal defect (n = 2). Patients had either severe pulmonary stenosis and/or moderate to severe pulmonary regurgitation.

RESULTS

All patients had successful percutaneous implantation of the 23 mm SAPIEN THV under general anesthesia. Fluoroscopy times ranged from 16 to 49 mins and procedure times ranged from 110 to 237 mins. The RV:systemic pressure ratio decreased from 78 +/- 18 to 39 +/- 8%, the RVOT gradient improved from 60.7 +/- 24.3 to 14.9 +/- 6.9 mm Hg, no patients had pulmonary insufficiency, and all patients had symptom improvement. At a maximum follow-up of 3.5 years (median 22.5 months), Doppler peak gradients ranged from 7-36 mm Hg, and there is no evidence of late stent fracture or structural valve failure.

CONCLUSION

The SAPIEN THV can be used successfully in the treatment of patients with right ventricle to pulmonary artery homograft failure. The valve is durable to at least 3.5 years without stent fracture or regurgitation. Clinical trials are underway to assess the long-term safety and efficacy of this valve.

Percutaneous pulmonary valve implantation: impact of evolving technology and learning curve on clinical outcome

BACKGROUND

Percutaneous pulmonary valve implantation was introduced in the year 2000 as a nonsurgical treatment for patients with right ventricular outflow tract dysfunction.

METHODS AND RESULTS

Between September 2000 and February 2007, 155 patients with stenosis and/or regurgitation underwent percutaneous pulmonary valve implantation. This led to significant reduction in right ventricular systolic pressure (from 63+/-18 to 45+/-13 mm Hg, P<0.001) and right ventricular outflow tract gradient (from 37+/-20 to 17+/-10 mm Hg, P<0.001). Follow-up ranged from 0 to 83.7 months (median 28.4 months). Freedom from reoperation was 93% (+/-2%), 86% (+/-3%), 84% (+/-4%), and 70% (+/-13%) at 10, 30, 50, and 70 months, respectively. Freedom from transcatheter reintervention was 95% (+/-2%), 87% (+/-3%), 73% (+/-6%), and 73% (+/-6%) at 10, 30, 50, and 70 months, respectively. Survival at 83 months was 96.9%. On time-dependent analysis, the first series of 50 patients (log-rank test P<0.001) and patients with a residual gradient >25 mm Hg (log-rank test P=0.01) were associated with a higher risk of reoperations.

CONCLUSIONS

Percutaneous pulmonary valve implantation resulted in the ability to avoid surgical right ventricular outflow tract revision in the majority of cases. This procedure might reduce the number of operations needed over the total lifetime of patients with right ventricle-to-pulmonary artery conduits.