Repair of Rheumatic Mitral Stenosis Using the SCORE Technique

In this video, the authors present a case of severe rheumatic mitral stenosis repaired using the SCORE technique—a stepwise approach that stands for Shaving, Checking, Opening (Commissurotomy), and Relaxing. 

The case involved a 43-year-old female patient, who was 154 cm in height and weighed 56 kg, with a BMI of 23.4. She complained of breathlessness after physical exertion. 

Upon physical examination, her chest was symmetrical with no deformity. The heart examination revealed a normal apex beat, no thrills, and an enlarged heart border. A grade 3/6 systolic murmur was heard at the mitral area, and her lower limbs showed no edema. Routine blood tests were unremarkable. 
 
The diagnostic workup determined that the chest X-ray showed a prominent pulmonary artery and a typical rheumatic mitral cardiac silhouette. The ECG displayed biphasic P waves in leads V4 to V6.  
 
Transthoracic echocardiography findings included rheumatic mitral valve disease and  
severe mitral stenosis with nil regurgitation. The mitral area was measured at 0.9 cm², with a mean gradient of 11 mmHg and a peak gradient of 18 mmHg. The E wave was recorded at 180cm/s, and the left atrium was enlarged, measuring 58 mm.  
 
The overall impression indicated rheumatic heart disease stage D with severe mitral stenosis, classified as cardiac function class III, according to the NYHA classification, and an STS score of 1.5 percent.  
 
Surgical Indication Overview 

According to current guidelines, percutaneous mitral balloon commissurotomy (PMBC) is indicated for rheumatic mitral stenosis in symptomatic patients at stage D with a pliable valve, no clot, and less than 2+ mitral regurgitation (MR), classified as Class I, Level of Evidence A. This patient met those criteria. The decision to pursue surgical repair was based on a previous study and high-volume experience with rheumatic mitral repair, which showed a better quality of life and fewer valve-related complications in the repair cohort compared to replacement. Additionally, the valve function restoration was found to be more sustainable and physiological than ballon plasty.  

Intraoperative transesophageal echocardiography (TEE) confirmed the severely restricted bi-leaflet motion, with extensive valve thickening, commissural fusion, and subvalvular stenosis was detected as well. 
 
Surgical Procedure 

A lower hemisternotomy approach was utilized for the procedure. The patient underwent rheumatic mitral valve repair with a 36 mm annuloplasty ring, tricuspid valve repair with a 28 mm ring, and left atrial plication for appendage closure. Cardiopulmonary bypass time was 121 minutes, with an aortic cross-clamp time of 77 minutes. 

This procedure followed the SCORE technique, a systematic method developed for rheumatic mitral repair.  

SCORE stands for Shaving, Checking, Opening, and Relaxing—four key steps designed to restore mobility and function to the rheumatic mitral valve by addressing both commissural fusion and subvalvular stenosis. 

Surgical steps 

Placement of the annuloplasty sutures was performed routinely. Valve assessment was conducted with two nerve hooks to expose the bilateral commissural area and determine the extent of fusion.  
 
The SCORE procedure was then carried out. First, shaving of the thickened area and minimal calcification in the C1 area was addressed with a 15# scalpel. Gentle pushing and shaving with the cutting edge upward facilitated dissection within the right plane to avoid leaflet perforation. Once the fibrotic plaque was removed, flexibility of the commissure was eventually achieved, allowing the following steps to proceed.  
 
During the checking phase, by repeatedly approximating the P1 and A1 toward the closure line, the exact commissural fusion course and insertion endpoint were ascertained, which is crucial for a precise commissurotomy in the following steps. 
 
For the commissurotomy, once the exact commissural fusion course and endpoint point were determined, commissurotomy was initiated from the fusion edge with a No. 11 scalpel blade. It was crucial to keep the cutting edge facing upward to avoid unintentional chordal rupture, a key factor contributing to postoperative pericommissural regurgitation. The supporting chordae beneath were carefully reallocated to the respective A1 and P1. 
 
In the relaxing phase, the fused anterior papillary muscles and chordae tendinea supporting C1 were fully exposed and assessed. Subsequently, a precise muscle division was performed to restore the normal subvalvular anatomy and relieve stenosis at the C1 level. Muscle splitting with the blade was kept no deeper than half of the length to avoid injury to the left ventricular (LV) posterior wall.  
 
This maneuver was repeated in the C2 area accordingly. 
 
Subsequently, in view of the extensive valve thickening and the young age of the patient, fibrous tissue stripping was added to maximize long-term durability and reduce the likelihood of reintervention. The purpose of this step was to restore leaflet pliability and enhance coaptation. While further studies and follow-up are needed to confirm whether this technique improves repair durability, intraoperative inspection confirmed a more normal-looking valve following the procedure. 
 
Completion of the mitral repair was finally achieved, with saline tests conducted before and after ring annuloplasty (size 36 mm) demonstrating satisfactory repair outcomes with no residual regurgitation and adequate mitral valve opening. 
 
Immediate postoperative transesophageal echocardiography (TEE) in the operating room confirmed significant improvement in leaflet motion, with complete elimination of subvalvular stenosis. The peak gradient was measured at 0.6mmHg and the mean gradient at 0.4 mmHg, while planimetry of the mitral orifice area (MOA) was 3.0 cm². No newly onset MR was detected. 
 
Conclusion 

This case demonstrated the efficacy of the SCORE technique in rheumatic mitral valve repair, successfully restoring function through systematic commissural and subvalvular reconstruction.

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