Abstract
A 75 year-old female with symptomatic severe mitral regurgitation of a bio-prosthetic valve secondary to valve leaflet perforation due to endocarditis underwent a mitral valve in valve replacement in an existing Hancock 27 mm valve using a trans-femoral/trans-septal approach. The procedure was complicated by an iatrogenic atrial septal defect post trans-septal puncture causing a severe right-to-left shunt due, possibly, to the combination of severe pulmonary hypertension and moderate tricuspid regurgitation the patient had suffered from at base line. Once the sheath was removed an immediate desaturation was observed which required emergent closure with an AMPLATZER ASD Occluder device (St. Jude Medical/Abbott Structural, St. Paul, Minnesota, MN). This stabilized the patient and returned her blood oxygen levels to normal. The case brings forth a rare but important complication that may occur during trans-septal procedures especially when using large sheaths. It emphasizes the importance of proper echocardiographic and hemodynamic evaluation prior to such procedures in order to be prepared for such complications.
Highlights
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Mitral Valve in Valve Implantation is a treatment option for prosthetic valve damage
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Trans -femoral procedure to implant the valve requires a trans-septal approach
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Commonly a minimal atrial septal defect remains, however it is not clinically significant
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Emergent need of atrial septal defect closure may occur if the patient is clinically unstable
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Hemodynamic assessment may be valuable to assess those patients who are at risk for such a complication
1
Introduction
Mitral regurgitation (MR) is the most prevalent form of valvular disease in the western world [ ]. Valve replacement or repair is indicated in most severe cases. Prior studies have demonstrated that the surgical risk is increased in patients with impaired left ventricular function, older age and comorbidities [ ]. The surgical risk is significantly further increased when adding prior cardiac surgery to the equation owing to the increased in-hospital mortality rates that are as high as 12% and a length of hospital stay of 2 to 3 weeks [ ]. Transcatheter trans-septal (TS) mitral valve in valve implantation (TMViV) provides a promising alternative with acceptable outcomes in high-risk patients with degenerated bioprostheses [ ]. Over the last two decades the rates of TS procedures has increased tremendously [ ]. However, these procedures carry a risk of iatrogenic complications. Persistent iatrogenic atrial septal defect (iASD) rates after using large TS sheaths for these structural interventions has increased with rates of up to 50% with 22Fr sheaths [ ]. Although the majority of iASDs are of no clinical and/or hemodynamic significance, a number of case reports have described clinically significant iASDs requiring rapid evaluation and emergent closure [ , ]. Due to the small number of cases little is known as to the reasons for this complication and thus no specific recommendations are provided regarding the possible evaluation prior to the procedure that might give hint to this complication and aid in better preparation. Nevertheless, once a right to left (R-L) shunt appears during the procedure, there is a clear indication to close the iASD immediately.
We present herein a case of an elderly patient with an unusually significant iASD occurring during a mitral valve in valve implantation. The need for rapid evaluation and treatment for a symptomatic iASD and pre-procedure assessment is also discussed.
2
Case presentation
The patient is a 79-year-old female patient with a bio-prosthetic mitral valve. Her medical history includes diabetes, hypertension, paroxysmal atrial fibrillation and status post stroke 7 years ago leaving her with right sided hemiplegia.
She underwent surgical mitral valve replacement with a Hancock 27 mm bio-prosthetic valve (Medtronic, Minneapolis, MN, USA) due to severe MR. Prior to surgery she underwent coronary angiography which revealed significant coronary disease and thus she had also had coronary bypass with a left internal mammary artery to the left anterior descending artery. Her echocardiography post-surgery demonstrated a normal functioning bio-prosthetic valve.
Six months post-surgery she was hospitalized for five days of fever and chills. In her admission she reported a tooth extraction 10 days prior to her admission, after receiving a single dose of 1 g amoxicillin prophylactically. During this hospitalization, six blood culture tests came back positive for Corynebacterium striatum , a transthoracic echocardiography showed no vegetations and no valvular malfunction. She was diagnosed with endocarditis and due to bacterial resistance was treated with vancomycin for a period of 6 weeks. A follow-up echocardiography demonstrated mildly elevated gradients across the mitral valve without vegetations.
Four months after completing her antibiotic treatment, the patient was hospitalized due to pulmonary edema. An echocardiography revealed severe MR of the bio-prosthetic valve with a perforation of one of the leaflets. The patient was treated conservatively; she responded well and was discharged. Due to the fact that she was considered to be at high risk for repeat surgical valve replacement, based on Society of Thoracic Surgeons (STS) score of 9.3% for redo surgery, prior stroke with residual right sided hemiplegia and severe pulmonary hypertension, she was readmitted electively for a TMViV procedure after meticulous Heart Team discussion.
On admission, the patient was stable and her oxygen saturation was normal. Her physical examination was normal except for a 3/6 holosystolic murmur heard best at the apex. Laboratory tests were normal aside for a hemoglobin of 10.7 g/dL, creatinine of 1.44 mg/dL and an LDH of 1251 U/L. Her ECG demonstrated a normal sinus rhythm, right bundle branch block, T wave inversion at V2-V4 chest leads and ST depression at V5-V6.
Just prior to the procedure, a transesophageal echo (TEE) was performed ( Fig. 1 ) which demonstrated severe MR, slightly increased gradients over the valve with a maximal/mean of 23/6 mm Hg, moderate tricuspid regurgitation, severe right ventricular (RV) dysfunction, severe bi-atrial enlargement and importantly, also severe pulmonary hypertension with estimated pulmonary artery systolic pressure of 61 mm Hg.
After gaining femoral access with a 16FR sheath, a TS puncture was performed and an AGILIS (St. Jude Medical/Abbott Structural, St. Paul, Minnesota, MN) deflectable catheter was then advanced across the septum, allowing for a 0.035′ guidewire placement in the left ventricle and exchanged for a pre-shaped stiff wire to allow for trans-atrial septal expansion with a 14 mm diameter ARMADA balloon (Abbott Vascular, CA, USA) ( Fig. 2 ).
A 29 mm Edwards SAPIEN 3 valve (Edwards Lifesciences, CA, USA) was implanted in the mitral position ( Fig. 3 ), once the valve was implanted the regurgitation was eliminated and the patients’ systolic blood pressure increased from 90 mm Hg to 150 mm Hg.
However, once the catheter was removed from across the septum, a sudden drop in oxygen saturation occurred from 99% to 87%. An echocardiogram ( Fig. 4 ) was immediately preformed revealing a 7 mm residual ASD with a significant practically unidirectional R-L shunt with a velocity time integral (VTI) of 41 cm, so that the volume across the defect at each beat was 16 cm 3 . We calculated that at a heart rate of 72 beats per minutes, it translates into a flow of 1.2 L/min through the ASD. Due to the emergent circumstances we were unable to calculate the Qp/Qs.
Due to the sudden clinical deterioration of the patient owing to a significant residual ASD with R-L shunt, we immediately prepared and implanted a 14 mm AMPLATZER ASD Occluder device (St. Jude Medical/Abbott Structural, St. Paul, Minnesota, MN). An immediate rise in oxygen saturation to 99% was observed once the device was implanted and sealed the septum. A TEE demonstrated no residual interatrial shunt ( Fig. 5 ). The patient was transferred in stable condition to the cardiac intensive care unit and was discharged from the hospital 5 days later. On echo prior to discharge no flow was noted through the ASD and her estimated systolic pulmonary artery pressure was 29 mmHg.
