Secondary Logo

Journal Logo

Role of Transesophageal Echocardiography in Surgery for Hemitruncus Arteriosus

Misra, Satyajeet MD, DNB, PDCC, TEE (EACVI), FTEE*; Koshy, Thomas DA, MD, PDCC, FTEE, FIACTA*; Shriram Lovhale, Pravin MD*; Mathew, Thomas MS, MCh

doi: 10.1213/ANE.0000000000002306
Perioperative Echocardiography and Cardiovascular Education
Free
SDC

Published ahead of print July 24, 2017.

From the *Department of Anesthesiology and Department of Cardiovascular and Thoracic Surgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India.

Accepted for publication April 24, 2017.

Published ahead of print July 24, 2017.

Funding: None.

The authors declare no conflicts of interest.

Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website.

Reprints will not be available from the authors.

Address correspondence to Satyajeet Misra, MD, DNB, PDCC, TEE (EACVI), FTEE, Department of Anesthesiology, All India Institute of Medical Sciences (AIIMS), Bhubaneswar, Odisha, India. Address e-mail to misrasatyajeet@gmail.com.

An 8-month-old infant weighing 4 kg underwent repair of right hemitruncus arteriosus. Written consent was obtained from the parents for this report. Intraoperative transesophageal echocardiography (TEE) was performed with a Philips IE 33 machine (Philips Ultrasound, Bothell, WA) and a pediatric two-dimensional (2D) TEE probe (X8-3t, Philips). The right pulmonary artery (RPA) was seen arising from the proximal ascending aorta in the midesophageal (ME) aortic valve (AV) long-axis view (Figure 1; Supplemental Digital Content 1, Video 1A, http://links.lww.com/AA/B877). High-velocity flow was seen in the proximal ascending aorta with mild flow acceleration at the level of the AV. The modified ascending aortic (AA) short-axis view showed the main pulmonary artery (MPA) continuing as the left pulmonary artery (LPA) with only a rudimentary stump in place of RPA, without any flows across it (Figure 2; Supplemental Digital Content 1, Video 1B, http://links.lww.com/AA/B877). A patent ductus arteriosus (PDA) with bidirectional shunt (Supplemental Digital Content 2, Video 2A, http://links.lww.com/AA/B878) and the LPA (Supplemental Digital Content 2, Video 2B, http://links.lww.com/AA/B878) were visualized in the upper esophageal aortic arch long-axis view.

Figure 1.

Figure 1.

Figure 2.

Figure 2.

The PDA was ligated and divided on initiation of cardiopulmonary bypass. The RPA was seen arising posterolaterally from the aortic root (Figure 3). It was resected from the aorta and reanastomosed to the MPA. Other surgical findings included a subaortic membrane just below the AV, which was excised. After separation from cardiopulmonary bypass, laminar flows were demonstrated in the MPA and RPA with no evidence of stenosis on 2D or color flow Doppler (CFD) (Supplemental Digital Content 3, Video 3, http://links.lww.com/AA/B879). The postsurgical period was uneventful.

Figure 3.

Figure 3.

Hemitruncus arteriosus involves anomalous origin of a branch pulmonary artery (PA) from the aorta, with the other PA arising from MPA; the semilunar valves are normal.1 The incidence is estimated at 0.1% of all congenital cardiovascular anomalies. The right hemitruncus variant where the RPA arises from the aorta is more common.1 Associated cardiac anomalies are more commonly seen in the left hemitruncus arteriosus (Table).2 Surgical repair is performed in infancy; otherwise, these children develop severe PA hypertension since 1 lung is exposed to systemic arterial pressures and the other lung receives the entire right ventricular cardiac output.1

Table.

Table.

A combination of 2D and CFD is used to demonstrate the anomalous RPA arising from the proximal ascending aorta in the ME AV long-axis view. Additionally, in the AA short-axis view, the MPA is seen continuing only as the LPA. This confirms the diagnosis of right hemitruncus arteriosus.

PDA is present in 69% of patients with right hemitruncus arteriosus. It is usually seen in the upper esophageal short-axis views.3 Interposition of the trachea between the esophagus and the distal AA/proximal aortic arch often results in poor visualization of these structures; saline-filled balloons have been used to minimize ultrasound scattering and improve visualization.3 In infants, however, because of a short trachea, good images of distal AA/proximal aortic arch can be obtained in the upper esophageal views, as compared to adults.

It is important to distinguish PDA from LPA with spectral and CFD, as with slight rotation of the probe, both the structures are often seen in this view.4 In contrast to continuous flows in the PDA seen with spectral and CFD, flow in the LPA occurs only in systole and is toward the TEE probe. The MPA is frequently dilated in the presence of PDA due to the left to right shunt; and this may also result in volume overload of the left heart. Antegrade diastolic flows seen in the LPA in this case may have been due to the runoff from the PDA.

High-velocity flows were seen in the aortic root and may have been due to the anomalous RPA take off. In the presence of high-velocity flows and elevated gradients, the anomalous PA can be test clamped before commencing cardiopulmonary bypass. Persistence of elevated gradients after clamping the anomalous PA is more suggestive of a fixed systemic left ventricular outflow tract (subvalvular or supravalvular) obstruction.

The important goal of post-bypass TEE was to rule out MPA-RPA anastomotic stenosis. 2D is a better modality to delineate anastomotic stenosis, since in severe obstruction, the MPA flow may runoff predominantly into the LPA, thus underestimating the severity of the stenosis by both spectral and CFD. Cutoff values for gradients suggestive of stenosis have not been described.

In this case, to delineate the anastomosis, a modified ME long-axis view was used. From the ME AA long-axis view, at the level of RPA, the probe was gently turned leftward in a counterclockwise direction. This maneuver aligned the MPA and proximal RPA in the long-axis plane. This view is well aligned with spectral Doppler and allows for interrogation of gradients across the anastomosis.

TEE is increasingly being used in surgery for congenital heart disease and is now a standard of care.5

Back to Top | Article Outline

Clinician’s Key Teaching Points

By Kent H. Rehfeldt, MD, and Nikolaos J. Skubas, MD

  • Hemitruncus arteriosus is a rare congenital condition, in which 1 of the branch PA arises from the ascending aorta while the other arises normally from the main PA. Right hemitruncus arteriosus is more common than left hemitruncus arteriosus, although the latter is more frequently associated with other cardiac anomalies.
  • With TEE, visualization of the anomalous take off of the right PA from the ascending aorta may be accomplished using the ME long-axis view using 2D and color Doppler imaging. The normal continuity of the left PA with the main PA may be seen in the ME AA short-axis view. The presence of high-velocity flow in the ascending aorta may represent flow at the anomalous right PA takeoff. Persistence of turbulence in the ascending aorta after clamping of the right PA may suggest the presence of coincidental subvalvular or supravalvular aortic stenosis.
  • In this case, a patient with right hemitruncus arteriosus was also noted to have a PDA, an associated finding in more than two-thirds of these patients. The PDA was distinguished from the left PA by noting continuous flow in the former and predominantly systolic flow in the latter. After resection of the right PA from the ascending aorta and reanastomosis to the main PA, 2D imaging did not show any anastomotic stenosis and color Doppler demonstrated laminar flow in both the main and right PA.
  • Two-dimensional imaging remains a key component of the TEE examination after hemitruncus repair. In the event of PA anastomotic stenosis, main PA flow could be preferentially directed into the contralateral, normal PA with resultant low velocity recorded across the stenotic area during spectral Doppler interrogation. Specific flow velocities indicative of anastomotic stenosis have not been described.
Back to Top | Article Outline

DISCLOSURES

Name: Satyajeet Misra, MD, DNB, PDCC, TEE (EACVI), FTEE.

Contribution: This author helped design and prepare the manuscript.

Name: Thomas Koshy, DA, MD, PDCC, FTEE, FIACTA.

Contribution: This author helped in preparing the manuscript.

Name: Pravin Shriram Lovhale, MD.

Contribution: This author helped in preparing the manuscript.

Name: Thomas Mathew, MS, MCh.

Contribution: This author helped in preparing the manuscript.

This manuscript was handled by: Nikoloas J. Skubas, MD, DSc, FACC, FASE.

Back to Top | Article Outline

REFERENCES

1. Prifti E, Bonacchi M, Murzi B, et al. Anomalous origin of the right pulmonary artery from the ascending aorta. J Card Surg. 2004;19:103–112.
2. Diab K, Richardson R, Pophal S, Alboliras E. Left hemitruncus associated with tetralogy of fallot: fetal diagnosis and postnatal echocardiographic and cardiac computed tomographic confirmation. Pediatr Cardiol. 2010;31:534–537.
3. Song H, Liu F, Dian K, Liu J. Echo rounds: intraoperative transesophageal echocardiography-guided patent ductus arteriosus ligation in an asymptomatic nonbacterial endocarditis patient. Anesth Analg. 2010;111:878–880.
4. Tsai SK, Chang CI, Wang MJ, et al. The assessment of the proximal left pulmonary artery by transesophageal echocardiography and computed tomography in neonates and infants: a case series. Anesth Analg. 2001;93:594–597.
5. Ayres NA, Miller-Hance W, Fyfe DA, et al.; Pediatric Council of the American Society of the Echocardiography. Indications and guidelines for performance of transesophageal echocardiography in the patient with pediatric acquired or congenital heart disease: report from the task force of the Pediatric Council of the American Society of Echocardiography. J Am Soc Echocardiogr. 2005;18:91–98.

Supplemental Digital Content

Back to Top | Article Outline
Copyright © 2017 International Anesthesia Research Society