Left ventricular outflow tract obstruction following mitral valve replacement: effect of strut height and orientation

Double-layer horizontal cross sutures for intra-atrial mitral valve implantation: An effective surgical method for severe mitral annular calcification

Objective

Severe mitral annular calcification (MAC) can make prosthetic implantation extremely difficult. Although intra-atrial mitral valve prosthesis implantation without annular decalcification offers a simpler approach, it poses a potential rupture risk due to high left ventricular pressure. We developed a double-layer (DL) horizontal cross-suture technique, which ensures close proximity of the valve prosthesis to the calcified annulus and segregates the left atrial wall from the left ventricle. The aim of this study was to compare the outcomes of DL suture with conventional single-layer (SL) suture in patients with severe MAC.

Methods

This retrospective cohort study consecutively enrolled patients with severe MAC undergoing mitral valve replacement at Beijing Anzhen Hospital from May 2018 to December 2022. A detailed description of the DL suture method is described. Follow-up medical evaluations, including transthoracic echocardiography measurements, were obtained through outpatient chart reviews.

Results

The study included 10 patients in the DL suture group and 20 in the SL suture group. All patients in the DL group and all but 3 in the SL group achieved technical success. Compared with the SL group, the DL suture technique was associated with lower rates of perivalvular leakage, stroke, new-onset atrial fibrillation, reoperation, and 30-day mortality. Follow-up was complete, with 1 late mortality in the DL group due to stroke and 4 cardiovascular deaths in the SL group.

Conclusions

The DL horizontal cross-suture technique offers a more effective and safer approach for intra-atrial mitral valve implantation in severe MAC cases than the conventional SL suture method.

Morphology display and hemodynamic testing using 3D printing may aid in the prediction of LVOT obstruction after mitral valve replacement

AIMS

Left ventricular outflow tract(LVOT) obstruction after mitral valve replacement can be life-threatening once occur. We simulated mitral valve replacement preoperatively using dynamic, three-dimensional(3D) printed models to help predict LVOT obstruction in this study.

METHODS

56 patients who underwent mitral valve replacement were included. Prediction of LVOT obstruction in vitro was based on the data from 4 sources: digital, anatomical, flexible, and dynamic model. Digital 3D models were designed based on computed tomography (CT) image dataset and printed with photopolymer resin to create a 3D anatomical model, which contributed to the morphology display. Then, flexible models were made from specialized silicone, which is similar to cardiac tissue in terms of its softness and elasticity. Dynamic function was achieved by coupling flexible models to a mock circulatory system (MCS). Besides, surgery simulation and hemodynamic testing was done using dynamic 3D printed model and patients were regrouped based on hemodynamic change. Finally, different methods for prediction of LVOT obstruction as well as classification based on two-dimensional image data and dynamic model were compared with surgical results as golden standard.

RESULTS

(1)Qualitatively, the prediction of LVOT obstruction using the dynamic 3D model was the most accurate and was consistent with clinical outcomes. In the four patients who developed LVOT obstruction after surgery, only two were at a high risk based on the other three models. (2)Quantitatively, the area of neo-LVOT predicted by the digital, anatomical, and flexible models was higher compared with the dynamic models and in-vivo after surgery. (3)Classification based on traditional criteria(two-dimensional image data) was different from surgical results. While the difference between dynamic model and surgical results was not statistically different.

CONCLUSIONS

After coupling the flexible model with the mock circulatory system, the dynamic 3D model predicted LVOT obstruction more accurately with hemodynamic testing compared with morphological evaluation. 3D printing can assist surgeons to better plan mitral valve replacement than traditional image data.

The Mitral Coaptation to Ventricular Septal Space: Two- and Three-Dimensional Transesophageal Echocardiographic Assessment

OBJECTIVES

To assess the dimensions and changes in the CSEPT (space between the ventricular septum and mitral coaptation point) before and after cardiopulmonary bypass (CPB) and to compare patients with and without aortic valve stenosis (AS) undergoing cardiac surgery.

DESIGN

Retrospective review of intraoperative transesophageal echocardiographic examinations.

SETTING

Single academic medical center.

PARTICIPANTS

The study comprised 91 elective cardiac surgical patients-30 with AS scheduled for aortic valve replacement and 61 without AS (non-AS).

INTERVENTIONS

Two- and 3-dimensional (2D and 3D) analysis of the CSEPT before and after CPB.

MEASUREMENTS AND MAIN RESULTS

Assessment of the CSEPT distances and areas was performed using 2D and 3D imaging before and after CPB. Two-dimensional measures of CSEPT distances were performed using midesophageal 5-chamber and long-axis windows. Three-dimensional measures were performed offline using multiplanar reconstruction. The CSEPT space was smaller after CPB (p < 0.01). Before and after CPB, the midesophageal 5-chamber and long-axis windows were similar to each other, and both were larger than the pre-CPB 3D CSEPT distance. Patients with AS had smaller before and after CPB distances and areas compared with non-AS patients (p < 0.05). The change in CSEPT area in AS patients was 24%.

CONCLUSIONS

The CSEPT space is smaller after CPB and more so for patients with AS undergoing aortic valve replacement. Two-dimensional CEPT distances vary compared with 3D CSEPT distances. Additional study using Doppler analysis will elucidate the added value of 3D assessment of the CSEPT space.

The Stented Porcine Bioprosthesis: A 50-Year Journey Through Hopes and Realities

The year 2018 marked the 50th anniversary of the first implant of a commercially manufactured stented porcine bioprosthesis. During the subsequent years considerable clinical and pathologic research was done to evaluate the overall performance of such devices and to identify the leading causes of failure. This brief review covers 5 decades, summarizing the initial hopes and the realities faced by surgeons who have believed from the start in these cardiac valve substitutes. From reported failures and long-term results a new generation of durable and reliable stented porcine bioprosthetic valves is currently available.

Ventricular Septal Perforation Caused by the Strut of a Mitral Valve Bioprosthesis

Ventricular rupture is a well-known complication of mitral valve replacement. We report a rare complication in which the strut of a recently implanted mitral bioprosthesis eroded through the ventricular septum. We present the strategy of the reoperation in which the sutures holding the repair patch were also used to support the new prosthesis. In addition to ventricular rupture and obstruction of the left ventricular outflow tract by a mitral bioprosthesis, the risk of iatrogenic ventricular septal defect (VSD) should be considered when choosing, sizing, and implanting a mitral bioprosthesis.

Multimodal sonographic approach for assessing left ventricular outflow tract gradient

Real-time three-dimensional echocardiography has now become an additional tool in the armamentarium of the perioperative echocardiographer. The use of all sonographic tools currently at the disposal of modern ultrasound technology enabled the correct diagnosis to be made in our patient. As a consequence, additional unnecessary surgery was avoided.

Cardiac valve prostheses at autopsy: an analysis of 337 cases with clinicopathologic correlation

We evaluated the pathologic findings at autopsy in 337 patients who had undergone cardiac valve replacement over 10 years (1982 to 1991). Rheumatic heart disease was the most common indication for valve replacement (84% of cases). Among the 255 patients with short-term survival (<1 month), in 162 cases (63.5%), the cause of death was related to surgery and/or underlying cardiovascular conditions. Host-prosthetic valve interactions contributed to mortality in 14.9% cases. However, in longtime survivors (82 patients), a significant number (86.5%) showed evidence of prosthesis-related complications, such as infective endocarditis, thrombosis, anticoagulant-related hemorrhage, and bioprosthetic valve degeneration.

Cardiac valve prostheses: pathological and bioengineering considerations

Cardiac valve replacement with mechanical prosthetic or bioprosthetic devices enhances patient survival and quality of life. Nevertheless, prosthesis-associated complications are frequent and contribute significantly to outcome. Thromboembolic complications are the most important problems in patients with mechanical valves, necessitating chronic anticoagulation in all patients receiving them. In contrast, patients with bioprosthetic valves, composed of chemically treated animal tissues, generally do not require anticoagulants. However, bioprostheses fail frequently by degeneration, especially that involving cuspal calcification. This paper reviews the pathological and bioengineering considerations in the selection of cardiac prosthetic valves and the management of patients who have received these devices. The significance, morphology, and pathogenesis of the observed major complications and other alterations during function are described in detail. Contemporary investigative trends are summarized, including studies of inhibition of mineralization and other degenerative changes in bioprostheses, improved design rigid mechanical valves with pyrolytic carbon occluders and the development of central-flow, flexible polymeric leaflet valves.