Surgical Repair for Primary Tricuspid Valve Disease: Individualized Surgical Planning With 3-Dimensional Printing.

Primary tricuspid valve (TV) disease is rare and associated with high operative mortality. Optimal surgical planning requires a precise understanding of the pathological features; however, detailed imaging of the TV can be challenging. We present 4 cases of primary TV disease where 3-dimensional printing was pivotal to operative planning and success. (Level of Difficulty: Advanced.).

Methods

All patients in this case series underwent 3-dimensional (3D) transesophageal echocardiography (TEE) and dedicated contrast-enhanced 4-dimensional (4D) computed tomography (CT) according to the following protocol: electrocardiographically synchronized, spiral acquisition, with contrast timing optimized to the right-sided chambers. For this purpose, bolus tracking with a manual trigger when the contrast agent reached the pulmonary artery was used. Thin reconstructions (0.6 mm) were exported into imaging processing software version 22.0 (Materialise Mimics Medical, Leuven, Belgium) to delineate and segment the right-sided structures, including the tricuspid valve (TV) annulus and leaflets. A midsystolic phase was chosen in cases of tricuspid regurgitation (TR), and a mid-diastolic phase was chosen in the case of tricuspid stenosis. Patient-specific 3D models were then printed using soft tissue material for the right-sided chambers and valve leaflets and rigid material for the pacemaker leads (if present).

Learning Objectives

To understand the role of multimodality imaging in the pre-operative planning of primary TV disease.

To highlight the value of 3D printing in surgical planning optimization and patient education.

The cardiologist and cardiac surgeon used the 3D printed models during their encounters with the patients to illustrate the specific valve disease and anticipated repair. The patients expressed a markedly improved understanding of their valve disease and planned operation. All operations were performed through a median sternotomy on an arrested heart.

History of presentation

A 66-year-old woman with no prior cardiac history presented with progressive fatigue, exertional dyspnea, and abdominal bloating. Physical examination revealed elevated jugular venous pressure, a holosystolic murmur over the left sternal border, and mild pitting lower extremity edema.

Investigations

Transthoracic echocardiography (TTE) showed severe TR and right atrial and right ventricular (RV) dilatation with preserved RV function (Figure 1A). TEE revealed a flail anterior leaflet (Figure 1B). On further questioning, the patient reported a remote bike accident with a chest contusion many years ago. The 4D CT scan also showed the flail anterior leaflet (Figure 1C, Video 1) and was used to segment the patient’s right-sided anatomy (Figure 1D) in systole (30% R-R interval).

Figure 1

Case 1

(A) Transthoracic echocardiography showing severe tricuspid regurgitation and right ventricular dilatation. (B) 3-dimensional multiplanar transesophageal echocardiography showing flail anterior leaflet (yellow arrows). (C) 4-dimensional computed tomography showing the flail segment of the anterior tricuspid valve leaflet (red arrows). (D) 3-dimensional model of the tricuspid valve. (E) 3-dimensional model of the tricuspid valve printed in systole (red asterisk shows the flail or prolapsing segment). (F) Intraoperative image showing the flail segment (asterisk) of the anterior leaflet overriding the septal leaflet. The coronary sinus cannula (blue arrow) is positioned in the coronary sinus, adjacent to the septal leaflet. The red arrow points to the direction of the aortic root (not visualized in this image). A = anterior; CS = coronary sinus; P = posterior; PA = pulmonary artery; PV = pulmonic valve; RAA = right atrial appendage; S = septal; SVC = superior vena cava.

Management

The 3D model was then printed (Figure 1E) and used for surgical planning and patient education. The flail anterior leaflet was visualized intraoperatively (Figure 1F), and the TV was repaired with the insertion of artificial chords to the anterior leaflet and placement of a 26-mm Edwards MC3 ring (Edwards LifeSciences LLC, Irvine, California). Post-operative TTE showed a well-seated TV ring with only trace TR (Video 2).

A 47-year-old man with ischemic cardiomyopathy and a primary prevention implantable cardioverter-defibrillator, which was previously replaced twice because of pocket infection and lead recall, presented with leg edema, abdominal distention, and a 25-pound weight gain.

Laboratory test results were notable for N-terminal pro–B-type natriuretic peptide of 1,286 ng/dl. TTE showed severe TR and a dilated right ventricle with relatively preserved function (Figure 2A), whereas 3D TEE revealed a flail segment of the anterior leaflet (Figure 2B). A 4D CT scan with an artifact reduction algorithm (to decrease the lead-related beam hardening artifact) was performed (Figure 2C) and used to segment the right-sided anatomy, including the torn anterior leaflet (Figure 2D) and the implantable cardioverter-defibrillator lead located between the septal and posterior leaflets.

Figure 2

Case 2

(A) Transthoracic echocardiography showing torrential tricuspid regurgitation and right ventricular dilatation. (B) 3-dimensional transesophageal echocardiography showing a flail segment of the anterior tricuspid valve leaflet (red arrow). (C) 4-dimensional computed tomography images with artifact reduction algorithm. (D) 3-dimensional model showing the torn anterior leaflet (red asterisk) and the implantable cardioverter-defibrillator lead (blue arrow). (E) 3-dimensional printed model demonstrating the torn anterior leaflet (red asterisks) and the implantable cardioverter-defibrillator lead (blue arrow) between the septal and posterior leaflets. (F) Intraoperative image showing the torn anterior leaflet held with the forceps. The anterior leaflet extends from 7 to 2 o’clock and is torn approximately at 12 o’clock. The detached pacemaker lead (PM) is visualized on the right side of the tricuspid valve orifice, and the Swan-Ganz catheter is visualized to the left of the pacemaker. Ao = aorta; AV = aortic valve; IVC = inferior vena cava; L = lead.

The 3D model was printed (Figure 2E) and shown to the patient, who reported a significant improvement in his understanding of the disease and anticipated repair. Intraoperatively, as expected, the anterior leaflet was found to be torn (Figure 2F). The patient underwent successful reconstruction of the anterior leaflet and annuloplasty with a 28-mm Edwards MC3 ring. Follow-up echocardiography showed trace TR (Video 3).

A young woman in her 20s presented with progressive decline in her exercise capacity and leg edema. She had a history of congenital complete heart block and dual-chamber pacemaker implantation.

Physical examination was notable for a diastolic murmur in the left lower sternal border and elevated jugular venous pressure. TTE showed severe TV stenosis with a mean gradient of 13 mm Hg (Figure 3A) that increased to 17 mm Hg with exercise. TEE showed commissural fusion of the TV leaflets and tethering of the subvalvular apparatus to the RV lead with a TV area of 1 cm2 on 3D planimetry (Figure 3B). The 4D CT scan showed a severely narrowed TV orifice with leaflet thickening, fusion, and extensive fibrosis of the subvalvular apparatus (Figure 3C).

Figure 3

Case 3

(A) Transthoracic echocardiography tricuspid inflow continuous wave Doppler imaging showing severe tricuspid stenosis. (B) Transesophageal echocardiography showing commissural fusion and tethering of the tricuspid valve apparatus to the right ventricular lead (red arrows). (C) 4-dimensional computed tomography images showing commissural fusion and thickening of the subvalvular apparatus with tethering to the right ventricular lead (blue arrows). (D) 3-dimensional model of the tricuspid valve and pacemaker leads visualized from the right atrium. Blue arrow, ventricular lead; red arrow, atrial lead. (E) Intraoperative findings of thickened and fused leaflets around the pacemaker lead (yellow arrow), which is adherent to the anterior leaflet and the subvalvular apparatus. All the leaflets are partially scarred, and there is fusion between the septal and posterior leaflets. The planned commissurotomy between the septal and posterior leaflets is depicted with the dotted black line. (F) Intraoperative image showing the adhesions between the pacemaker lead (blue arrow) and right ventricular trabeculation (yellow arrow). The pacemaker lead is gently detached from the leaflets and subvalvular apparatus. CS = coronary sinus; RV = right ventricle.

A 3D printed model was generated in diastole (Figure 3D), matching the intraoperative findings (Figure 3E): commissural fusion with severe thickening and retraction of the chordae of the septal and anterior leaflets. The patient underwent commissurotomy and division of the fused and retracted chordae (Figure 3F). A 28-mm Edwards MC3 annuloplasty ring was placed, and the transvenous pacemaker leads were replaced by an epicardial system. Post-operative TEE showed an excellent result (Video 4). Follow-up TTE 1 month later showed a well-seated ring with a mean TV gradient of 6 mm Hg, and the patient reported significant improvement in her symptoms.

A 66-year-old woman with no prior cardiac history presented with progressive dyspnea and a loud systolic murmur.

TTE showed severe TR and RV dilatation. TEE revealed a lack of central coaptation of the TV leaflets during systole and a linear gap extending anterolaterally through the anterior leaflet (Figure 4A). It was uncertain whether this linear gap represented an artifact or an actual defect (i.e., a cleft). However, on color Doppler imaging, the TR jet extended from the center through the defect (Figure 4B), consistent with the presence of an anterior leaflet cleft.

Figure 4

Case 4

(A) 3-dimensional transesophageal echocardiography in systole showing incomplete central leaflet coaptation with a linear “gap” (yellow arrow) extending anterolaterally through the anterior leaflet. (B) 3-dimensional transesophageal echocardiography with color Doppler showing a central jet extending through the anterolateral linear gap of the anterior leaflet (yellow arrow). (C) 3-dimensional reconstruction showing the cleft (yellow arrow) between the 2 segments of the anterior leaflet (yellow and purple). (D) Ventricular view of the 3-dimensional printed model showing the cleft (yellow arrow) between the 2 segments of the anterior leaflet). (E) Intraoperative image showing the cleft in the anterior leaflet (yellow arrow). (F) Intraoperative image showing the sutures closing the anterior leaflet cleft (yellow arrow). The posterior leaflet (P) is barely seen. RCA = right coronary artery; RVOT = right ventricular outflow tract; other abbreviations as in Figures 1 and 2.

The 3D model, which was based on 4D CT segmentation, also showed the cleft (Figure 4C), and the printed 3D model (Figure 4D) matched the intraoperative findings (Figure 4E). The anterior cleft was closed successfully (Figure 4F), and a 28-mm Edwards MC3 annuloplasty ring was placed. Post-operative TTE showed a well-seated TV ring with trace TR (Video 5).

Discussion

Isolated primary TV disease is rare, accounting for <10% of TR cases. Causes include congenital heart disease, chest wall trauma, rheumatic heart disease, radiation, carcinoid syndrome, infectious endocarditis, and iatrogenic injury (leads and RV biopsies) (1,2).

In isolated severe primary TR, surgery is recommended for symptomatic patients nonresponsive to medical therapy (diuretics) or for asymptomatic or mildly symptomatic patients with progressive RV dilatation and/or dysfunction (3). Isolated TV surgery is associated with a relatively high post-operative mortality (up to 8.8%), and valve replacement is associated with even higher mortality compared with repair (4). The complexity of the operation and prolonged extracorporeal circulation times, along with the underlying RV and organ (liver and kidney) dysfunction related to late presentation, increase the risk for vasoplegia, coagulopathy, and multiorgan failure post-operatively (1).

Given the rarity of isolated primary TV disease, the surgical experience is relatively limited, and optimal pre-procedural planning that is based on imaging is crucial. However, the complex anatomy of the TV, including its position in the chest (most anterior and caudal valve, retrosternal, and away from the esophagus), its thin leaflets that are variable in number and size, and the acoustic shadowing from device leads can pose challenges to accurate echocardiographic imaging of the TV disease. Multimodality imaging, including 4D CT, has been increasingly used to achieve a more detailed analysis of the TV leaflets and accurate measurements of the TV annulus and RV size (3).

On the basis of volumetric imaging datasets derived from these modalities, cardiovascular 3D printing has emerged as a valuable tool that enables advanced visualization and enhanced anatomic understanding in the entire range of structural, valvular, and congenital heart diseases (5).

Combining the technologies of high–spatial resolution cardiac imaging, image processing software, and 3D printing to create patient-specific models of various cardiovascular disorders offers a valuable additional perspective to the diagnosis and management of these conditions (6).

Several applications of 3D-printed models have been reported, including medical education and physician training, procedural planning and simulation, and device innovation, as well as patient communication (6,7).

From a proceduralist’s perspective, printed models add 3D spatial and tactile dimensions to a patient’s specific cardiovascular disease, thus leading to improved 3D conceptualization and enhanced visuospatial skills (8). The ultimate goals are to optimize pre-procedural planning, tailor the procedure to the patient’s specific anatomy, prepare for anticipated complications, and shorten the operative and extracorporeal circulation times, with a potential decrease in post-operative multiorgan dysfunction.

From the patient’s perspective, personalized 3D models have the potential to alleviate anxiety about the upcoming procedure by improving understanding of the disease and the anticipated operation and by enhancing the patient-doctor relationship and communication.

Conclusions

Isolated primary TV disease is a rare and complex entity with high post-operative mortality. Patient-specific 3D-printed models can be used for comprehensive assessment of the TV anatomy, pre-procedural planning, and patient education translating into excellent results.

3D printing is an immensely promising technology with the potential to revolutionize the field of personalized medicine and establish a new paradigm of how we image, plan, and perform cardiovascular interventions. The beneficial effect of 3D printing on clinical and procedural outcomes should be the focus of future studies in the field of advanced cardiovascular imaging and interventions.

Author Disclosures

Dr. Wierup is a consultant for Edwards Lifescience, Medtronic, and CryoLife. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.