Totally endoscopic transaortic septal myectomy with 3-dimensional visualization for hypertrophic obstructive cardiomyopathy: A case report

A, LVOT exposure via aortotomy. B, Resected hypertrophied basal septum after myectomy.

Central Message.

TETSM using the DCT technique with 3-dimensional visualization is a safe and effective minimally invasive alternative to conventional myectomy in selected patients with HOCM.

Hypertrophic obstructive cardiomyopathy (HOCM) is a genetic cardiac disorder characterized by asymmetric septal hypertrophy and dynamic left ventricular outflow tract (LVOT) obstruction.¹ In patients who are symptomatic, surgical septal myectomy remains the gold standard treatment, effectively relieving obstruction and improving symptoms and survival.²

Minimally invasive approaches, particularly robot-assisted techniques, have demonstrated excellent outcomes in septal myectomy by enhancing visualization and instrument precision.³ However, robotic systems remain unavailable in many institutions because of cost and infrastructure limitations. In such settings, totally endoscopic techniques with 3-dimensional (3D) visualization represent a feasible and effective alternative, offering reduced surgical trauma, fewer complications, and expedited recovery. Here, we present a case of totally endoscopic transaortic septal myectomy using a novel DCT technique (ie, Double-port approach, Camera and main port in the same intercostal space, Totally endoscopic with skin incision <3 cm) with 3D visualization, demonstrating its safety and potential in a patient with symptomatic HOCM at a center without robotic systems.

Case Presentation

A 63-year-old female patient presented with a 4-month history of progressive exertional dyspnea, fatigue, and occasional chest discomfort. Findings of a physical examination were unremarkable. The patient was hemodynamically stable with normal oxygen saturation on room air. She had no significant medical history and no known family history of hypertrophic cardiomyopathy.

Transthoracic echocardiography revealed asymmetric septal hypertrophy with a maximal interventricular septal thickness of 15.86 mm and preserved left ventricular ejection fraction of 65.6%. Systolic anterior motion (SAM) of the anterior mitral leaflet was present, resulting in severe mitral regurgitation (vena contracta 8 mm) and dynamic LVOT obstruction with a peak gradient of 99 mm Hg (Vmax 498 cm/s). The anterolateral apical wall was also thickened at 15.4 mm (Figure 1, A). Cardiac computed tomography confirmed basal septal hypertrophy, with maximal septal thickness measuring approximately 14 mm (Figure 1, B). The patient was initially treated with bisoprolol, but symptoms worsened over time, necessitating surgical intervention.

Figure 1.

A, Transthoracic echocardiography showing asymmetric interventricular septal hypertrophy. B, Cardiac computed tomography confirming basal septal hypertrophy at the level of the left ventricular outflow tract.

After multidisciplinary evaluation, the patient was scheduled for totally endoscopic transaortic septal myectomy using a novel DCT technique performed with 3D endoscopic visualization.⁴ This approach is a minimally invasive adaptation of the classical Morrow procedure.

Cardiopulmonary bypass was initiated through percutaneous cannulation of the femoral artery and vein. Surgical access was achieved via a right anterior mini-thoracotomy with the creation of a 2.5-cm skin incision at the third intercostal space (ICS) near the nipple line. To facilitate exposure, a soft-tissue retractor was applied. A 5-mm port was inserted into the second ICS for instrumentation, and another 10-mm port was positioned in the third ICS along the anterior axillary line to accommodate the 3D endoscopic camera. Another 5-mm incision was created for aortic crossclamping and left ventricular venting, positioned between the camera trocar and the instrumentation trocar (Figure 2). After aortic crossclamping (cross time 93 minutes), transverse aortotomy was performed to expose the hypertrophied basal septum. Left venting was performed through the right superior pulmonary vein. Guided by 3D visualization, a targeted myectomy was performed, extending from the nadir of the right coronary cusp to the anterior mitral leaflet (Figure 3).

Figure 2.

The procedure was performed using the novel DCT technique (Double-port with the Camera and main port in the same ICS, Totally endoscopic with a <3-cm incision) under 3-dimensional visualization.

Figure 3.

A, Endoscopic view through the aortotomy showing exposure of the left ventricular outflow tract after transverse aortic incision. B, Completed myectomy demonstrating resection of hypertrophied basal septal myocardium.

Intraoperative saline testing revealed mild residual mitral regurgitation, attributed to SAM-related leaflet traction. Given the absence of significant structural leaflet pathology and the expected improvement after septal resection, no additional mitral intervention was undertaken. The aortotomy was closed with double-layer continuous 4-0 polypropylene suture (Video 1). Total cardiopulmonary bypass time was 125 minutes. One pericardial drainage tube was positioned through the transverse sinus beneath the ascending aorta, and one right pleural drainage tube was placed.

The patient was extubated 8 hours postoperatively and discharged on postoperative day 2. Predischarge transthoracic echocardiography confirmed complete resolution of LVOT obstruction and only trivial mitral regurgitation. One-month postoperative cardiac magnetic resonance imaging scan demonstrated normal biventricular function and no residual gradient (Figure 4). At 2-month follow-up, echocardiography confirmed stable findings with unobstructed LVOT flow, normal mitral valve function, and a mean/peak aortic valve gradient of 4/2 mm Hg. University Medical Center institutional policy dictates that single-patient reports do not require institutional review board approval. Written informed consent for publication of the study data was obtained from the patient.

Figure 4.

Magnetic resonance imaging at 1-month follow-up showing unobstructed left ventricular outflow tract.

Discussion

According to the 2024 American College of Cardiology/American Heart Association Guideline for the Management of Hypertrophic Cardiomyopathy, surgical septal myectomy is recommended for patients with drug-refractory symptoms (typically New York Heart Association class III-IV) and a resting or provoked LVOT gradient ≥50 mm Hg (class I, Level of Evidence B).² Myectomy is particularly indicated in cases with associated SAM of the mitral valve and significant mitral regurgitation. In our case, the patient fulfilled all guideline-based criteria for intervention, presenting with persistent symptoms despite beta-blocker therapy, severe dynamic LVOT obstruction, and SAM-related mitral regurgitation.

Given the patient's low operative risk and our institution's experience with advanced minimally invasive techniques, a totally endoscopic approach was deemed appropriate.⁵ Minimally invasive myectomy has gained increasing acceptance in selected HOCM cases as the result of its potential to reduce surgical trauma, shorten hospitalization length of stay, and expedite recovery without compromising efficacy. Although robotic-assisted procedures yield excellent outcomes, limited access restricts their availability in many centers.³ In this context, totally endoscopic techniques with 3D visualization offer a feasible and effective alternative. We used the DCT technique, defined by a double-port approach with both the camera and working instrument inserted through the same intercostal space and a skin incision <3 cm. This approach satisfies the criteria for “totally endoscopic” surgery while maintaining optimal visualization and instrument control⁴ and was therefore selected for this patient.

We selected the transaortic approach for septal myectomy because it provides direct visualization of the hypertrophied basal septum and facilitates precise resection while preserving the integrity of the mitral subvalvular apparatus. In contrast, the transmitral approach often necessitates extensive manipulation of the mitral valve and chordal structures, which may increase the risk of valvular injury. The transaortic route also follows a familiar surgical trajectory, particularly advantageous in centers with established experience in aortic and multivalve procedures. At our institution, this approach has been routinely applied using standardized endoscopic port placement, enabling safe and efficient execution of the procedure.⁴

The application of the “DCT technique” enabled a comprehensive septal myectomy comparable in extent to the classical Morrow procedure, achieved with acceptable cardiopulmonary bypass and aortic crossclamp durations (125 and 93 minutes, respectively), and without intraoperative complications. Postoperative imaging demonstrated complete resolution of LVOT obstruction and preserved function of both the mitral and aortic valves, thereby affirming the technical feasibility and clinical efficacy of this minimally invasive approach in appropriately selected patients with hypertrophic obstructive cardiomyopathy.

Conclusions

Totally endoscopic transaortic septal myectomy using the DCT technique with 3D visualization is a feasible and effective option for selected patients with HOCM. This approach offers precise myocardial resection, preserves valve integrity, and achieves favorable outcomes with minimal invasiveness. However, a limitation of this report is that it represents only a single case; therefore, definitive criteria for patient selection cannot be established, and we can only share our preliminary experience.

Conflict of Interest Statement

The authors reported no conflicts of interest.

The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest.

Supplementary Data

Video 1

Detailed operative steps of the procedure. Video available at: https://www.jtcvs.org/article/S2666-2507(25)00446-8/fulltext.