Anterior Leaflet Augmentation With CorMatrix Porcine Extracellular Matrix in Twenty-Five Patients: Unexpected Patch Failures and Histologic Analysis.
BACKGROUND
This study reported on the treatment of Carpentier type IIIa and type IIIb mitral regurgitation (MR) with a large patch anterior mitral valve leaflet augmentation technique using CorMatrix (CorMatrix Cardiovascular Inc, Alpharetta, GA) extracellular matrix (ECM).


METHODS
A single-site chart review was conducted on patients who underwent anterior leaflet augmentation performed with the Da Vinci surgical robot (Intuitive Surgical, Sunnyvale, CA) or through a median sternotomy. Only patients who had anterior leaflet augmentation with porcine intestine ECM or autologous pericardium were included. Follow-up echocardiography was performed on all patients. Histologic specimens were available on ECM patches from a subset of patients who required reoperation.


RESULTS
Between August 2011 and April 2014, 44 patients (mean age, 62.6 ± 12.2 years) underwent anterior leaflet augmentation with either porcine intestinal ECM or autologous pericardium at the Temple University Hospital in Philadelphia. Two (4%) late deaths occurred, one in each group. One patient who underwent ECM augmentation died of non-cardiac-related causes 7 months after discharge as a result of complications of chronic renal failure. The second late death occurred 5 months after discharge because of complications of a stroke in a patient in the pericardial augmentation group. Eight (32%) of the patients with ECM had recurrence of severe MR on echocardiography at an average time of 201 ± 98 days. Seven (28%) patients required reoperation because of failure of the ECM patch including perforation (4%), excessive patch dilation (20%), and suture line dehiscence (4%). In contrast, none of the patients with pericardial augmentation developed severe MR or required operation. Statistical analysis of the patients with ECM augmentation demonstrated no correlation of the following: age; sex; comorbid conditions such as diabetes, chronic obstructive pulmonary disease, and hypertension; left ventricular ejection fraction; surgical approach; annuloplasty size; or type of MR with patch failure. A lower body mass index was the only factor associated with recurrent severe regurgitation on univariate analysis (p = 0.039). Histologic study of the four available explants demonstrated intense inflammation without evidence of host integration. The remaining 15 (60%) patients had normal mitral leaflet structure and function on follow-up echocardiograms out to 12 months.


CONCLUSIONS
For type III MR, a large anterior leaflet patch technique with porcine ECM was associated with a 32% recurrence rate of severe MR related directly to patch failure. Further research and development should be performed on the use of ECM materials with a goal to decrease the failure rate experienced in this study.
Department of Surgery, Dwight D. Eisenhower Army Medical Center, Augusta, Georgia.
Thomas M
TM
Kelley
Department of Cardiovascular Surgery, Temple University School of Medicine, Philadelphia, Pennsylvania.
Mohammed
M
Kashem
Department of Cardiovascular Surgery, Temple University School of Medicine, Philadelphia, Pennsylvania.
He
H
Wang
Department of Cardiovascular Surgery, Temple University School of Medicine, Philadelphia, Pennsylvania.
James
J
McCarthy
Department of Cardiovascular Surgery, Temple University School of Medicine, Philadelphia, Pennsylvania.
Nels D
ND
Carroll
Department of Cardiovascular Surgery, Temple University School of Medicine, Philadelphia, Pennsylvania.
G William
GW
Moser
Department of Cardiothoracic Surgery, Weill Cornell Medical College, New York, New York. Electronic address: sloaneguy@med.cornell.edu.
T Sloane
TS
Guy
D000818:Animals; D001705:Bioprosthesis; D004452:Echocardiography; D005109:Extracellular Matrix / Q000637:transplantation*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000175:diagnosis / Q000601:surgery*; D010496:Pericardium / Q000637:transplantation*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012189:Retrospective Studies; D013552:Swine