Mini-invasive surgical instruments in transaortic myectomy for hypertrophic obstructive cardiomyopathy: a single-center experience with 168 cases

Abstract

Background Although septal myectomy is a standard strategy for managing patients with hypertrophic obstructive cardiomyopathy (HOCM) and drug-refractory symptoms, so far, only a few experienced myectomy centers exist globally. Mainly, this can be explained by the many technical challenges presented by myectomy. From our clinical experience, applying the mini-invasive surgical instruments during myectomy potentially reduces the technical difficulty. This study reports the preliminary experience regarding transaortic septal myectomy using mini-invasive surgical instruments for managing patients with HOCM and drug-refractory symptoms; also, we evaluate the early results following myectomy. Methods Between March 2016 and March 2019, consecutive HOCM patients who underwent isolated transaortic septal myectomy using the mini-invasive surgical instruments were enrolled in this analysis. Intraoperative, in-hospital and follow-up results were analyzed. Results We included 168 eligible patients (83 males, mean 56.8 ± 12.3 years). The midventricular obstruction was recorded in 7 (4.2%) patients. All patients underwent transaortic septal myectomy with a mean aortic cross-clamping time of 36.0 ± 8.1 min. During myectomy, 9 (5.4%) patients received repeat aortic cross-clamping. Surgical mortality was 0.6%. Notably, 5 (3.0%) patients developed complete atrioventricular block, they needed permanent pacemaker implantation. The median follow-up time was 6 months; however, no follow-up deaths occurred with a significant improvement in New York Heart Association functional status. We reported a sharp decrease in the maximum gradients from the preoperative value (11.6 ± 7.4 mmHg vs. 94.4 ± 22.6 mmHg, p < 0.001). The median degree of mitral regurgitation fell to 1.0 (vs. 3.0 preoperatively, p < 0.001) with a significant reduction in the proportion of moderate or more regurgitation (1.2% vs. 57.7%, p < 0.001). Conclusions Mini-invasive surgical instruments may be beneficial in reducing the technical challenges of transaortic septal myectomy procedure. Of note, transaortic septal myectomy using the mini-invasive surgical instruments may present with favorable results.

Primeval outcomes of thoracoscopic transmitral myectomy with anterior mitral leaflet extension for hypertrophic obstructive cardiomyopathy

“…In clinical practice, some HOCM patients may have residual SAM despite septal myectomy or alcohol ablation; and SAM may also occur in non-HOCM patients, such as those with intrinsic mitral valve disease, indicating that SAM has a complex mechanism related to structures and function of the ventricle. [27][28][29] In our study, three patients whose interventricular septum thickness was less than 12 mm still had persistent or recurrent SAM, despite myectomy with a patch extension. Concretely, we observed one of the SAM was caused by residual obstruction (>30 mmHg), whereas the other two were caused by an extremely long AML, and an oversized patch, respectively.…”

“…Finally, the valve apparatus and function are simultaneously affected by ventricular pressure, mitral leaflet length and thickness, chordal attachments and arrangement, and annulus geometry, which may explain why concomitant mitral valve intervention is necessary for some HOCM patients. In clinical practice, some HOCM patients may have residual SAM despite septal myectomy or alcohol ablation; and SAM may also occur in non‐HOCM patients, such as those with intrinsic mitral valve disease, indicating that SAM has a complex mechanism related to structures and function of the ventricle 27–29 . In our study, three patients whose interventricular septum thickness was less than 12 mm still had persistent or recurrent SAM, despite myectomy with a patch extension.…”

Hypertrophic cardiomyopathy with latent obstruction: Clinical characteristics and surgical results

“…Further exposure of subaortic structures was facilitated by a supine, left lateral position with the head up, the use of a headlamp and loupe magnification, and the application of two prolate retractors. The application of the mini-invasive surgical instruments was beneficial for an adequate length of septal excision [13] . Scalpel resection was usually started at the nadir of the right cusp, 5 mm below the aortic valve and extending leftwards to the left trigone.…”

Myectomy with and without Mitral Subvalvular Repair in Patients with Hypertrophic Obstructive Cardiomyopathy with Grade 3 to 4+ Mitral Regurgitation without Intrinsic Mitral Valve Disease: A Retrospective Observational Study

“…The range of the septal myectomy could be extended beyond the insertion of the papillary muscle and toward the apex of the LV. Mini-invasive operative instruments such as modified long-handled forceps and scissors were routinely utilized for the septal myectomy [ 23 ]; which allowed more extensive resection of the myocardium toward the LV apex.…”