Ann Thorac Surg 2001;71:1670-1672
© 2001 The Society of Thoracic Surgeons
Case report
Dissection of atrial septum after mitral valve replacement
Omar Di Gregorio, MDa,
Carmela Nardi, MDb,
Aldo Milano, MD, PhDa,
Marco De Carlo, MDb,
Maria Grana, MDc,
Uberto Bortolotti, MDa,*
a Division of Cardiac Surgery, Cardiac and Thoracic Department, University of Pisa Medical School, Pisa, Italy
b Division of Cardiology, Cardiac and Thoracic Department, University of Pisa Medical School, Pisa, Italy
c Division of Anesthesiology, Cardiac and Thoracic Department, University of Pisa Medical School, Pisa, Italy
Accepted for publication June 2, 2000.
* Address reprint requests to Dr Bortolotti, U. O. Cardiochirurgia, Ospedale Cisanello, Via Paradisa 2, 56124 Pisa, Italy (Email: u.bortolotti{at}cardchir.med.unipi.it).
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Abstract
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We report a patient who presented with paraprosthetic leak complicated by dissection of the interatrial septum after mitral valve replacement. A review of the literature provides confirmation that only 3 cases have been previously reported of this potential, albeit extremely rare, complication of prosthetic mitral valve replacement. Prosthesis oversizing and improper mitral annular handling appeared to be the predisposing factors of this complication.
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Introduction
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Many complications have been recognized to occur both early and late after cardiac valve replacement with various types of prostheses [1]. Among these the incidence of periprosthetic leaks is low but nevertheless a substantial mortality has been reported at reoperation [2, 3]. We report a patient who developed an early periprosthetic leak following mitral valve replacement (MVR) associated to dissection of the interatrial septum; the latter complication has been reported previously only three times in the literature [4–6].
In June 1999, a 55-year-old man, with a body surface area of 1.82 m2, had an MVR operation with a 31 mm St Jude Medical prosthesis (St Jude Medical, Inc, St Paul, MN) at another hospital because of severe mitral regurgitation. The postoperative course was complicated by pneumothorax, renal, and respiratory insufficiency, which required prolonged mechanical respiratory assistance and eventually a tracheostomy. Subsequently fever developed with positive sputum cultures for Staphylococcus aureus and chest roentgenogram findings of a pulmonary infiltrate with progressive deterioration of respiratory insufficiency. At this time a transthoracic two-dimensional echocardiogram raised the suspicion of recurrent mitral regurgitation due to a periprosthetic leak, and the patient was transferred to our unit for further treatment (approximately 1 month after the operation) at a relatives’ request. On admission to our intensive care unit the patient was mechanically ventilated and on moderate inotropic support with borderline hemodynamics. Chest roentgenogram showed basilar infiltrates and signs of pulmonary congestion. A transthoracic two-dimensional echocardiogram confirmed the presence of 3+ mitral regurgitation caused by a periprosthetic leak showing also a significant systolic flow from the left ventricle into an unusual structure that was interpreted as a chamber into the left atrial septum. A few hours after admission, progressive hemodynamic deterioration developed with hypotension, oliguria, and acidosis prompting reoperation despite a prothrombin activity of 30%. At reoperation, coarse pericardial adhesion was dissected after repeat median sternotomy. A transesophageal echocardiography confirmed the presence of severe mitral regurgitation and communication between the mitral annular area and the interatrial septum (Figs 1 and 2).
Moderately hypothermic cardiopulmonary bypass was instituted and the heart was arrested with antegrade cold blood cardioplegia. The left atrium was opened and a large prosthetic leak was noted between 2 and 4 o’clock at the posterolateral commissure with no apparent signs of active infection. The mitral prosthesis, which had been implanted by means of multiple buttress sutures, was explanted evidenceing in the commissural area almost no residual annular tissue and confirming the presence of a septal false chamber with inflow at the posteromedial aspect of the mitral annulus. A 29 mm Sorin Bicarbon prosthesis (Sorin Biomedica Cardio, Saluggia, Italy) was inserted using multiple stitches reinforced by Teflon felts placed in the supraannular position. At the site of the posterior commissure deep bites were taken to secure the prosthesis and simultaneously close the left atrial inflow to the septal dissection. The left atriotomy was closed, the air was evacuated, and the aortic cross-clamp was released. During rewarming the right atrium was opened and signs of blood infiltration of the interatrial septum were noted with a laceration at the floor of the fossa ovalis, which was closed by a continuous suture. The patient was weaned from bypass with moderate inotropic support, maintained on mechanical ventilation for 12 days, discharged to the ward on postoperative day 17, and transferred for rehabilitation to another hospital 15 days later. At the first follow-up visit (4 months after his second operation), he is doing well and the control echocardiogram shows a well-functioning mitral prosthesis.
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Fig 1. Transesophageal two-dimensional echocardiogram showing the atrial septal cavity (*) which dilates during ventricular systole. Arrows point to the left atrial wall of the cavity.
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Fig 2. Color Doppler shows two regurgitant systolic jets into the atrial septal cavity (left jet) and into the left atrium through the periprosthetic leak (right jet), respectively.
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Comment
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Dissection of the interatrial septum is a rare complication of MVR, which has been reported only three times so far (Table 1). The first case was reported by Goda and colleagues [4] in 1994 in a patient whose complication was diagnosed with transesophageal echo on the postoperative day 3 after replacement of a failing mitral bioprosthesis. Li Mandri and colleagues [5] observed the second case in 1994 in a 61-year-old man who had MVR with a mechanical prosthesis after a failed valvuloplasty. Dissection of the atrial septum was disclosed by transesophageal echocardiography a few days after the operation and he was treated by direct suture of both inflow and outflow of the newly created false chamber within the septum. However, the authors did not extensively discuss the mechanism underlying this complication. The third case was reported in the same year by Pretre and colleagues [6] who described dissection of the atrial septum occurring in a 74-year-old man 6 years and 2 months after MVR with a porcine bioprosthesis. The lesion was associated with recurrent periprosthetic leak and was dealt with by prosthetic replacement and direct suture of the interatrial cavity. An improper handling of the mitral annulus during the previous operation was considered as potential mechanism for this complication, which may have been favored by insertion of a large prosthesis as well. Interestingly, this complication also has been reported after percutaneous mitral balloon valvuloplasty for mitral stenosis [7].
In our patient, dissection of the interatrial septum occurred early after MVR and it was associated with a periprosthetic leak. Occurrence of such a combination of events explains the stormy postoperative course and persistent respiratory distress with inability to wean the patient from ventilatory support. In this case a combination of two mechanisms, oversizing of the mitral prosthesis and overzealous excision of mitral valve tissue, most likely explain both such complications. Indeed, it appeared that at the site of the leak little residual annular tissue was left so that stitches were previously passed into the atrial muscle with resultant tearing and subsequent dissection of the septum. Furthermore, at reoperation a smaller but still adequate mitral prosthesis proved to fit perfectly into the annulus.
The present case confirms that awareness of rare but potential complications after MVR is essential for the surgeon, particularly since it again underlines the importance of proper manipulation of the mitral annulus and related structures during MVR. It also emphasizes the effectiveness of transthoracic and transesophageal echocardiography in the postoperative management of patients after prosthetic valve replacement, and their role in detecting unusual complications after mitral valve procedures.
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References
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- Roberts WC. Complications of cardiac valve replacement. characteristic abnormalities of prostheses pertaining to any or a specific site. Am Heart J 1982;103:113-122.[Medline]
- Dhasmana JP, Blackstsone EH, Kirklin JW, Kouchoukos NT. Factors associated with periprosthetic leakage following primary mitral valve replacement. with special consideration of the suture technique. Ann Thorac Surg 1983;35:170-178.[Abstract/Free Full Text]
- Orszulak TA, Schaff HV, Danielson GK, Pluth JR, Puga FJ, Piehler JM. Results of reoperation for periprosthetic leakage Ann Thorac Surg 1983;35:584-589.[Abstract/Free Full Text]
- Goda T, Ishii K, Shiiya N, Oba J, Matsui Y, Yasuda K. Acute dissection of the interatrial septum after re-replacement of the mitral valve—a case report Nippon Kyobu Geka Gakkai Zasshi 1994;42:1092-1095.[Medline]
- Li Mandri G, Schwartz A, Rose EA, et al. Atrial septal dissection after mitral valve replacement demonstrated by transesophageal echocardiography Am Heart J 1994;127:219-221.[Medline]
- Pretre R, Murith N, Neidhart P, Luthi P, Faidutti B. Dissection of the atrial septum following mitral valve surgery J Card Surg 1994;9:61-64.[Medline]
- Tseng CD, Hsu KL, Tseng YZ, Chiang FT, Hwang JJ, Lin FY. Penetration of the interatrial septum. a rare complication of percutaneous transluminal mitral commissurotomy. J Formos Med Assoc 1997;96:272-275.[Medline]
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Abstract
Introduction
