Abstract
A 63-year-old man, status post-mitral valve repair for severe mitral regurgitation secondary to ruptured chordae of the anterior leaflet, was admitted seven years after surgery because of a recent history of hematuria. A new apical pansystolic murmur was audible. Hemoglobin level was 5.7 g/dL. Results of other hematologic studies and a peripheral blood smear were indicative of mechanical hemolysis. Transesophageal echocardiography showed a high-velocity jet of mitral regurgitation that directly collided with the annuloplasty ring. At re-operation, one of the artificial neochordae to A2 and A3 segments was found to be disrupted. The mitral valve was replaced with a 33/31 mm On-X valve. Hemolytic anemia disappeared immediately after surgery.
Although mitral valve repair with artificial neochodae has been shown to have long-term durability, it should be recognized that artificial neochordae may rupture a long time after mitral valve repair. Also, although hemolytic anemia is known as an early complication after mitral valve repair, it is worth knowing that hemolytic anemia may occur as a late complication after mitral valve repair. Continuous long-term monitoring of the patients after mitral valve repair is recommended.
<Learning objectives: Artificial neochordae may at times rupture long period after mitral valve repair. Also, although hemolytic anemia is known as an early complication after mitral valve repair, it may occur as a complication due to late rupture of artificial neochordae. Continuous long-term monitoring of the patient after mitral valve repair is recommended.>
Keywords: Mitral valve repair, Late rupture of artificial neochordae, Natural history of artificial neochordae, Hemolytic anemia
Introduction
Mitral valve repair is considered the procedure of choice to correct mitral regurgitation for degenerative valve disease. The use of artificial neochordae has been validated clinically over the past two decades with excellent long-term durability [1] since the introduction of expanded polytetrafluoroethylene (ePTFE) sutures for chordal replacement during mitral valve repair. However, the natural history of artificial ePTFE sutures is not completely understood and long-term outcome remains to be elucidated. In this report, a patient with sudden onset of hematuria seven years after mitral valve repair is described. The patient was found to have ruptured ePTFE neochordae associated with hemolytic anemia, which is generally known as an early complication after mitral valve repair [2], [3].
Case report
A 63-year-old man, status post-mitral valve repair for severe mitral regurgitation secondary to ruptured chordae of the anterior leaflet, was transferred to our hospital seven years after surgery because of shortness of breath on exertion. The patient had been well until five months previously, when hematuria suddenly developed. He was treated with prednisone under the tentative diagnosis of Coombs-negative autoimmune hemolytic anemia at a near-by district hospital. Although hematuria spontaneously disappeared one month later, he continued to feel unwell. On examination, he had normal vital signs but markedly pale conjunctivae. The third heart sound and grade 4/6 pansystolic murmur were audible at the apex. Hemoglobin level was 5.7 g/dL. Hematologic studies revealed a negative Coombs’ test with haptoglobin of <10 mg/dL, lactate dehydrogenase of 1803 U/L, and total bilirubin of 1.9 mg/dL (indirect level of 1.3 mg/dL). A peripheral blood smear showed schistocytes, spherocytes, polychromasia, and red cell fragmentation, suggestive of mechanical hemolysis (Fig. 1A).
Fig. 1.
(A) A peripheral blood smear revealing schistocytes and red cell fragmentation (white arrows) due to mechanical shearing of red blood cells, spherocytes (black arrows), and polychromasia (red arrows). (B) Transesophageal echocardiography showing a rapid acceleration flow of transvalvular mitral regurgitation (arrow) that collided with the annuloplasty ring (arrowhead).
Ao, aorta; LA, left atrium; LV, left ventricle; MV, mitral valve.
Transesophageal echocardiography showed a rapid acceleration jet of mitral regurgitation that directly collided with the annuloplasty ring, redirecting the jet into the left atrium (Fig. 1B). The patient was taken for reoperation in which one of the artificial neochordae to A2 and A3 segments was found to be fractured (Fig. 2). Endothelialization of the annuloplasty ring was incomplete in the area that was struck by the regurgitant jet. All of the artificial neochordae, Duran ring, and the anterior leaflet were resected and a 33/31 mm On-X valve was implanted. The patient had an uneventful postoperative recovery with resolution of hemolytic anemia.
Fig. 2.
Gross view of explanted mitral valve, showing ruptured artificial chordae (white arrow) and intact chordae (black arrows).
Discussion
A simple peripheral blood smear and hematologic studies revealed features of mechanical hemolytic anemia, which is generally known as an early complication after mitral repair, in a patient with ruptured artificial neochordae seven years after initial surgery, which seems not often reported but indicates the importance of long-term follow-up.
Mitral valve repair is considered the gold standard in surgery for degenerative mitral regurgitation. Because of the excellent long-term durability of mitral valve repair with ePTFE sutures, the use of artificial neochordae has been validated clinically over the past two decades [1]. The morbidity and reoperation rates related to artificial neochordae are comparable to those of classical Carpentier techniques with ring annuloplasty, quadrangular leaflet resection, and shortening or transposition of chordae. David et al. reported that freedom from reoperation at 10 years was 94% in patients who received ePTFE neochordae and 97% in patients in whom repair was performed without neochordae [1].
To date, five cases of late rupture of neochordae [4], [5], [6], [7] and six cases of early and intermediate rupture of neochordae [2], [3], [8], [9], [10] have been reported (Table 1). Most of the cases were rupture of neochordae to the anterior leaflet, probably because of the higher mechanical stress on the anterior leaflet after mitral valve repair. Although mitral valve repair with ePTFE neochordae has been shown to have excellent long-term durability and a possible low rate of structural deterioration, it should be recognized that artificial neochordae may rupture a long time after mitral valve repair.
Table 1.
Late and early-intermediate rupture of neochordae and hemolytic anemia.
| Author | Patient no. | Age (yrs) | Sex | Time to diagnosis | Hemolytic anemia | Initial diagnosis and MV repair | Findings at reoperation | Surgical intervention |
|---|---|---|---|---|---|---|---|---|
| Late rupture (≥6 yrs) | ||||||||
| Butany et al. [4] | 1 | 76 | F | 14 yrs | No | Rheumatic MS: insertion of neochordae, mitral ring | Ruptured neochordae with calcification | MVR, CABG |
| Coutinho et al. [5] | 2 | 68 | M | 6 yrs | No | Elongated and ruptured AML chordae (A2, A3): two pairs of neochordae (CV-5), mitral ring | AML: ruptured two pairs of neochordae, no calcification | Re-repair |
| 3 | 67 | M | 11 yrs | No | Thin and elongated chordae: two pairs of neochordae (CV-5), mitral ring | AML: ruptured one pair of neochordae with calcification | MVR | |
| Farivar et al. [6] | 4 | 57 | M | 11 yrs | Yes | Ruptured AML chordae: partial resection AML, two pairs of neochordae, mitral ring | AML: ruptured two pairs of thickened and stiffened neochordae | MVR |
| Bortolotti et al. [7] | 5 | 51 | M | 11 yrs | No | Elongated chordae: two pairs of neochordae (CV-5) (A3), one pair of neochordae (CV-5) (P3), mitral ring | AML: ruptured two pairs of neochordae, minimal calcification | MVR, AVR |
| Present case | 6 | 63 | M | 7 yrs | Yes | Ruptured AML chordae (A2, A3): three pairs of neochordae (CV-5) AML, mitral ring | AML: ruptured one pair of neochordae | MVR |
| Early-intermediate rupture (≦36 mos) | ||||||||
| Yeo et al. [2] | 1 | 44 | M | 4 mos | Yes | Insertion of neochordae, mitral ring | Ruptured neochordae | Re-repair |
| Lam et al. [3] | 2 | – | – | – | Yes | Not available | Ruptured neochordae | Not available |
| Yamashita and Skarsgard [8] | 3 | 60 | F | 14 mos | Yes | Ruptured AML chordae (A2): six neochordae (CV-5) (A1, A2), eight neochordae (CV-5) (A2, A3), mitral ring | AML: ruptured neochordae (A2,A3) | MVR |
| 4 | 78 | M | 2 mos | Yes | Ruptured AML chordae (A2): eight neochordae (CV-5) (A1, A2), eight neochordae (CV-5) (A2, A3), mitral ring | AML: all of the neochordae and native chordae ruptured | MVR | |
| Castillo et al. [9] | 5 | 55 | M | 4 mos | – | Congenital shortened chordae: two neochordae (CV-3) AML, one neochordae (CV-3) PML (P2), mitral ring | AML: ruptured neochordae, fibrosis and calcification of A2, AML tear | MVR |
| Kudo et al. [10] | 6 | 60 | F | 36 mos | – | Ruptured AML chordae (A1,A2,A3): insertion of six neochordae (CV-5), mitral ring | AML: ruptured neochordae (A3) | MVR |
AML, anterior mitral valve; AVR, aortic valve replacement; CABG, coronary artery bypass grafting; F, female; M, male; MS; mitral stenosis; MV, mitral valve; MVR, mitral valve replacement.
Hemolytic anemia is usually caused by mechanical destruction of red blood cells (fragmentation hemolysis). Although hemolytic anemia is most often seen in patients with malfunctioning prosthetic valves, it may at times be seen following mitral valve repair. Patients who develop hemolytic anemia have a high-velocity regurgitant jet and usually present within the first six months of mitral valve repair [3], [8]. Suggested hydrodynamic mechanisms responsible for hemolysis include collision of the regurgitant jet, fragmentation, rapid acceleration, slow deceleration, and freejet [2], [3]. However, at reoperation, the initial mitral valve repair was surprisingly intact in the majority of patients [2], [3]. Yeo et al. reported 13 patients with hemolytic anemia early after mitral valve repair, and only one patient was found to have ruptured neochordae [2]. Lam et al. reported 32 patients with hemolytic anemia early after mitral valve repair, and again only one patient had ruptured neochordae [3]. Hemolytic anemia is therefore generally considered as a mode of early repair failure without ruptured neochordae. In this context, hemolytic anemia caused by rupture of artificial neochordae seven years after initial surgery in our patient seems exceptional. However, it is important to rule out mechanical hemolytic anemia in all patients with a history of mitral valve repair presenting with anemia and a new regurgitant murmur, regardless of length of period after surgery.
Conflict of interest
All authors have no conflict of interest.
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