The patient gave written consent for publication of this report. A 43-year-old patient with symptomatic (dyspnea on exertion and palpitations) biventricular outflow tract obstruction was scheduled for a redo-cardiac surgery. The patient’s medical history included double outlet right ventricle (DORV), ventricular septal defect (VSD), and pulmonary stenosis (PS) (Fig. 1A) corrected with a Rastelli repair (Fig. 1B) at the age of 9 years. A preoperative transthoracic echocardiogram (TTE) 1 year previously showed a stenotic native right ventricular outflow tract (RVOT) and stenotic right ventricular (RV) to pulmonary artery (PA) conduit (homograft). The subaortic area was narrowed causing left ventricular outflow tract obstruction (LVOTO). Mild to moderate mitral regurgitation (MR) and tricuspid regurgitation (TR) were also present. The RV pressure was two third of systemic pressure on cardiac catheterization.
An intraoperative transesophageal echocardiogram (TEE) was performed in view of the altered anatomy and the additional findings are as follows. Supplemental Videos 1 and 2 (Supplemental Digital Content 1 and 2, http://links.lww.com/AA/B390, http://links.lww.com/AA/B391) display the pre-repair TEE findings. A midesophageal (ME) bicaval view displayed a hypertrophied RV (Supplemental Digital Content 1, Supplemental Video 1, http://links.lww.com/AA/B390). ME 4-chamber 2-dimensional (D) and color flow Doppler (CFD) views displayed mild TR and MR. The anterior mitral valve leaflet appeared elongated and thickened. ME RV inflow and outflow 2D and CFD views showed a narrowed native RVOT and a turbulent flow across the pulmonary valve (PV) (Supplemental Digital Content 1, Supplemental Video 1, http://links.lww.com/AA/B390). A continuous-wave Doppler (CWD) across the native RVOT and PV revealed a Vmax of 342 cm/s and pressure gradient (PG) of 47 mm Hg (Supplemental Digital Content 1, Supplemental Video 1, http://links.lww.com/AA/B390). An ME long-axis (LAX) 2D and CFD views revealed narrowed left ventricular outflow tract (LVOT) and turbulent flow. A deep transgastric 5-chamber CFD examination also confirmed the aortic insufficiency (AI). A CWD across the LVOT and aortic valve (AV) revealed a Vmax of 326 cm/s and PG of 43 mm Hg (Supplemental Digital Content 1, Supplemental Video 1, http://links.lww.com/AA/B390). The AV leaflets appeared thickened, and mild to moderate AI was present on CFD. An ME LVOT short-axis 2D (Fig. 2, A and B; Supplemental Digital Content 2, Supplemental Video 2, http://links.lww.com/AA/B391) and LAX view revealed an echogenic membrane and a muscular LVOT (Fig. 2C).
After a sternotomy and cardiopulmonary bypass, the RV to PA conduit was explanted (resulting in first ventriculotomy; Fig. 3A). A Konno procedure was performed. The procedure involved an aortotomy, aortic annular augmentation, extension of the incision onto the infundibulum, and the RVOT (Fig. 3B). This resulted in a second ventriculotomy on the RV. After the excision of the AV, the incision was extended onto the conal septum (Fig. 3C). The prosthetic AV (23 mm St Jude mechanical AV) was secured onto the widened aortic annulus (Fig. 3C). The old VSD patch was removed, and the conal septum was resected except in the posteroinferior portion.
A tailored pericardial patch was placed in the ventricular septum at the level of the aortic annulus. The patch was secured to the sewing rim of the prosthetic AV and also to close the aortotomy (Fig. 3D). The 2 ventriculotomies were connected because of their close proximity. Fused PV leaflets were released, and the native RVOT was dilated through the opening on the PA. The RV and PA openings were also closed using bovine pericardial patches (Fig. 3D). The patient was weaned from cardiopulmonary bypass (total 300 minutes). The RV pressures were 50% of systemic pressures on needle transduction. A postrepair TEE showed normal biventricular function, a widened LVOT (Fig. 2D), and laminar flow across the LVOT and AV (Supplemental Digital Content 3, Supplemental Video 3, http://links.lww.com/AA/B392). The MR and TR also improved. A CWD across the RVOT and PV revealed a PG of 4 mm Hg (Supplemental Digital Content 3, Supplemental Video 3, http://links.lww.com/AA/B392). A CWD across the LVOT and prosthetic AV showed a Vmax of 131 cm/s and a peak PG of 7 mm Hg (Supplemental Digital Content 3, Supplemental Video 3, http://links.lww.com/AA/B392). The trachea was extubated on day 2, and the patient was discharged subsequently. The TTE before discharge showed a moderate PS (PG of 30 mm Hg), normal prosthetic AV, normal left ventricular function, and no subaortic stenosis. Upon follow-up, the patient was doing well.
Biventricular outflow tract obstruction is rare in adults. We report a patient who presented with this condition after a Rastelli repair1 for DORV with VSD and PS. The DORV (a conotruncal anomaly)2 accounts for 4% to 8% of congenital heart conditions. It is caused because of lack of conotruncal inversion, leftward conoventricular shift, and persistence of subaortic conus. This results in both the great arteries and the outflow tracts arising from the RV. Rastelli repair was first described for the correction of transposition of great vessels with large VSD. Later Rastelli repair was also applied to correct subtypes of DORV. Reoperations in these corrected DORV patients are mainly because of RV to PA conduit obstruction, dehiscence (72.8%),1 or an LVOTO.3,4
Rastelli repair consists of 2-step processes based on redirecting the blood flow1,2; relieve the RVOTO, closure of the VSD, and LVOT reconstruction. First, an intracardiac tunnel is created using the mobilized conal septum and a pericardial patch (used to close the VSD), thus reconstructing the LVOT. The aim of this tunnel is to connect the left ventricle to the aorta and divert the blood flow. Second, RV outflow is bypassed using extra cardiac conduit to divert the blood into the PA, thus relieving the PS. This extra cardiac conduit approach may sacrifice the native PV (not the case in this patient). In 2 large series, only 20% to 25% of patients were free of RVOT reoperation at 20 years.1,2
Although our patient had recurrent RVOTO, she did well for >30 years. The patient subsequently developed symptoms secondary to the LVOTO. TEE was not helpful in delineating the extra cardiac conduit, but the PGs confirmed preoperative TTE findings (RVOTO). Augmentation of the RVOT and excision of the hypertrophied RV were adequate to reduce the PA pressure (to 50% of the systemic pressure). RVOT augmentation was necessary to prevent the prosthetic AV from impinging on the RVOT.
The incidence of LVOTO after Rastelli repair is approximately 17% of patients.1,5 The LVOTO usually occurs at the level of the repaired VSD or below the baffle because of failure of VSD and the baffle to enlarge as the patient grows.4 The reoperation rate for the LVOTO can range from 1% to 15%1 after 15 years of the initial operation. The LVOTO may also result from commissural fusion, subvalvular membrane/muscle, or accessory mitral valve tissue/chordal attachments.4 In this patient, the LVOT was tunnel-like and contained the old pericardial VSD patch and active muscular tissue. A Konno procedure5,6 was performed to correct this subaortic pathology. Compared with a myomectomy, the septal excision is anterior and lateral. Damage to the AV, AI, residual VSD, and conduction disturbances may occur after the Konno procedure. In this patient, the AV was replaced because of a preexisting AI and sclerosed valve leaflets.
Intraoperative TEE was particularly useful in assessing the nature of the subaortic stenosis and the AV. The TEE images were off-axis, and we used the LVOT as our reference point. The LVOT was identified in the ME LAX view. On the basis of this LAX view, the short-axis LVOT views were obtained at 2 levels: the first level was at the level of old VSD patch and the other at the conal septal level. This clearly explained the cause of the LVOTO as the unresected conal septum during the original Rastelli repair. Compared with the preoperative TTE, intraoperative TEE helped us in characterizing the anatomy of conal lesion. In addition, the AV sclerosis, AI, and complex native RVOT was evident on TEE. Cardiac magnetic resonance imaging7 is the “gold standard” in assessing the multilevel LVOTO and AV morphology.
In summary, biventricular outflow tract obstruction is a rare clinical presentation. Although RVOTO secondary to conduit problems is more common after a Rastelli repair, LVOTO may be a dominant pathology in some patients. Intraoperative TEE was critical to delineate the subaortic anatomy along with the AV. E
Clinician’s Key Teaching Points
By Nikolaos J. Skubas, MD, Kimberly Howard-Quijano, MD, and Martin J. London, MD
- In a double outlet right ventricle (DORV), the pulmonary artery (PA) and aorta both arise from the right ventricle (RV). DORV is a heterogeneous series of congenital anomalies, most commonly associated with pulmonic stenosis and a ventricular septal defect. In the setting of DORV with pulmonic stenosis, the surgical repair (Rastelli procedure) involves creation of a conduit from the RV to the PA to increase the RV output into the pulmonary circulation, reconstruction of the left ventricular (LV) outflow tract, and closure of the ventricular septal defect.
- Although RV to PA conduit obstruction is a common complication, the incidence of LV outflow obstruction after a Rastelli procedure is only 17% and most often because of failure of the subaortic area to enlarge as the patient grows. The anteriorly located RV to PA conduit lies in the far field of the transesophageal echocardiogram (TEE) imaging sector and may be challenging to image. The RV outflow tract should be evaluated in the midesophageal (ME) RV inflow-outflow or upper-esophageal arch short-axis views, whereas the LV outflow tract can be evaluated in the deep transgastric long-axis LV view. Obstruction should be suspected if turbulence is imaged with color flow Doppler and pressure gradients should be evaluated with spectral Doppler.
- In this case, an adult patient developed dyspnea on exertion 34 years after correction of DORV and was found to have biventricular outflow tract obstruction. In an ME aortic valve long-axis view, color flow Doppler revealed turbulent flow in the LV outflow tract and aortic valve regurgitation. TEE imaging of the ME aortic valve SAX view at different insertion depths subsequently identified the LV outflow tract obstruction as a subaortic stenosis at the level of the hypertrophic ventricular septum. At the same time, turbulence in the ME RV inflow-outflow view indicated RV outflow tract stenosis.
- Traditional TEE views may be inadequate to evaluate anatomy and function in congenital heart disease. Off-axis views and slight probe adjustments may be required to identify structures and evaluate function.
Name: Sridhar Reddy Musuku, MD, FRCA.
Contribution: This author prepared the manuscript and is responsible for the editing, schematics and choosing the video clips, and analyzing the videos. This author is also responsible for coordinating the submission process with other authors and he is the corresponding author.
Attestation: Sridhar Reddy Musuku approves and attests the final manuscript and he is the archival author.
Name: Neil Devejian, MD.
Contribution: This author is the primary surgeon and helped in surgical part of the manuscript preparation and editing.
Attestation: Neil Devejian attests the final manuscript.
Name: Saroj Pani, MD.
Contribution: This author helped with editing the manuscript.
Attestation: Saroj Pani attests the final manuscript.
Name: Kareem Kassel, MD.
Contribution: This author helped in preparing the manuscript and labeling the video clips.
Attestation: Kareem Kassel attests the final manuscript.
This manuscript was handled by: Martin J. London, MD.
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