Faculty Bibliography

Cardiac surgery patients with infected implantable cardioverter defibrillator hardware face high morbidity with both surgical and nonoperative management options. We present a case of infected epicardial patch defibrillator leads in a patient with prohibitively high risk of death with open surgical removal. As a less morbid alternative, an Eloesser flap was used to convert his presenting mediastinal empyema necessitans into a chronic, manageable wound.

OBJECTIVE: Although the benefits of minimally invasive valvular surgery are well established, the applicability of extending these techniques to reoperative aortic valve surgery is unknown. We evaluated our experience with a minimally invasive approach to this patient population. METHODS: From January 2010 to September 2015, 21 patients underwent reoperative isolated aortic valve replacement via a minimally invasive approach by a single surgeon. All patients had preoperative evaluation with computerized tomography and coronary catheterization. Surgical approaches were right anterior thoracotomy (6/21) or upper hemisternotomy (15/21). Central aortic cannulation was preferred with femoral artery cannulation used in four patients (19%). In patients with left internal mammary artery (LIMA) grafts, no attempt to dissect or occlude the graft was made. Cold blood cardioplegia was administered antegrade (12/21) or retrograde (9/21); systemic cooling with a mean low temperature of 27.5 degrees C was employed. RESULTS: Mean age was 75.1 years with a range from 33 to 92 years, and 67% (14/21) were male. All procedures were completed with a minimally invasive approach. Mean +/- SD cross-clamp time was 51.5 +/- 9.2 minutes. Fourteen patients had patent LIMA grafts. No aortic, LIMA, or cardiac injuries occurred. There were no hospital deaths nor occurrences of perioperative myocardial infarction, stroke, wound infection, renal failure, or endocarditis/sepsis. One patient required a reoperation for bleeding. Sixty-two percent of patients were discharged to home; mean +/- SD length of stay was 6 +/- 3 days. CONCLUSIONS: With appropriate preoperative evaluation and careful surgical planning, a minimally invasive approach to reoperative aortic valve surgery can be performed in a safe and effective manner.

BACKGROUND: Recurrence of mitral regurgitation (MR) after undersized mitral annuloplasty (MA) for ischemic MR is as high as 60%, with the recurrence rate likely due to continued dilation of the left ventricle (LV). To better understand the causes of recurrent MR, we studied the effect of undersized MA on strain in the LV wall. We hypothesize that the acute change in ventricular shape induced by MA will cause increased strain in regions nearest the mitral valve. METHODS: Finite element models were previously reported, based on cardiac magnetic resonance images of 5 sheep with mild to moderate ischemic MR. A 24-mm saddle-shaped rigid annuloplasty ring was modeled and used to simulate virtual MA. Longitudinal and myofiber strains were calculated at end-diastole and end-systole, with preoperative early diastolic geometry as the reference state. RESULTS: The undersized MA significantly increased longitudinal strain at end-diastole in the lateral LV wall. The effect was greatest in the proximal-lateral endocardial surface, where longitudinal strain after MA was approximately triple the preoperative strain (11.17% +/- 2.15% vs 3.45% +/- 0.92%, p = 0.0057). In contrast, postoperative end-diastolic fiber strain decreased in this same region (2.53% +/- 2.14% vs 7.72% +/- 1.79%, p = 0.0060). There were no significant changes in either strain type at end-systole. CONCLUSIONS: Undersized MA increased longitudinal strain in the proximal lateral LV wall at end-diastole. This procedure-related strain at the proximal-lateral LV wall may foster continued LV enlargement and subsequent recurrence of mitral regurgitation.

BACKGROUND: The TRANSFORM (Multicenter Experience With Rapid Deployment Edwards INTUITY Valve System for Aortic Valve Replacement) trial (NCT01700439) evaluated the performance of the INTUITY rapid deployment aortic valve replacement (RDAVR) system in patients with severe aortic stenosis. METHODS: TRANSFORM was a prospective, nonrandomized, multicenter (n = 29), single-arm trial. INTUITY is comprised of a cloth-covered balloon-expandable frame attached to a Carpentier-Edwards PERIMOUNT Magna Ease aortic valve. Primary and effectiveness endpoints were evaluated at 1 year. RESULTS: Between 2012 and 2015, 839 patients underwent RDAVR. Mean age was 73.5 +/- 8.3 years. Full sternotomy (FS) was used in 59% and minimally invasive surgical incisions in 41%. Technical success rate was 95%. For isolated RDAVR, mean crossclamp and cardiopulmonary bypass times for FS were 49.3 +/- 26.9 minutes and 69.2 +/- 34.7 minutes, respectively, and for minimally invasive surgical 63.1 +/- 25.4 minutes and 84.6 +/- 33.5 minutes, respectively. These times were favorable compared with Society of Thoracic Surgeons database comparators for FS: 76.3 minutes and 104.2 minutes, respectively, and for minimally invasive surgical, 82.9 minutes and 111.4 minutes, respectively (P < .001). At 30 days, all-cause mortality was 0.8%; valve explant, 0.1%; thromboembolism, 3.5%; and major bleeding, 1.3%. In patients with isolated aortic valve replacement, the rate of permanent pacemaker implantation was 11.9%. At 1 year, mean effective orifice area was 1.7 cm2; mean gradient, 10.3 mm Hg; and moderate and severe paravalvular leak, 1.2% and 0.4%, respectively. CONCLUSIONS: INTUITY RDAVR performed effectively in this North American trial. It may lead to a relative reduction in aortic crossclamp time and cardiopulmonary bypass time and has excellent hemodynamic performance. Pacemaker implantation rate observed was somewhat greater than European trials and requires further investigation.

OBJECTIVE: In patients with atrial fibrillation, 90% of embolic strokes originate from the left atrial appendage (LAA). Successful exclusion of the LAA is associated with a lower stroke rate in patients with atrial fibrillation. Surgical oversewing of the LAA is often incomplete when evaluated with transesophageal echocardiogram (TEE). External closure techniques of suturing and stapling have also demonstrated high failure rates with persistent flow and large stumps. We hypothesized that the precise visualization of a robotic LAA closure (RLAAC) would result in superior closure rates. METHODS: Before robotic mitral repair, patients underwent RLAAC; the base of the LAA was oversewn using a running 4-0 polytetrafluoroethylene suture in two layers. Postoperatively, the LAA was interrogated in multiple TEE views. Incomplete closure was defined as any flow across the LAA suture line or a residual stump of greater than 1 cm. RESULTS: Seventy-nine consecutive patients underwent RLAAC; no injuries occurred. On postrepair TEE, 73 of 79 patients had LAAs visualized well enough to thoroughly evaluate. Successful ligation was confirmed in 64 (87.7%) of 73 patients. Seven patients (9.6%) had small jet flow into the LAA; no residual stumps were noted. Two patients (2.7%) had undetermined flow. CONCLUSIONS: We have demonstrated excellent success with RLAAC; we postulate that this may be due to improved intracardiac visualization. Robotic LAA closure was more successful (87.7%) than previously reported results from the Left Atrial Appendage Occlusion Study for suture exclusion (45.5%) and staple closure (72.7%). With success rates equivalent to transcatheter device closures, RLAAC should be considered for robotic mitral valve surgical patients.

BACKGROUND: Recurrent mitral regurgitation after mitral valve repair is common, occurring in nearly 50% of patients within 10 years of surgery. Durability of repair is partly related to stress distribution over the mitral leaflets. We hypothesized that repair with neochords (NCs) results in lower stress than leaflet resection (LR). MATERIALS AND METHODS: Magnetic resonance imaging and 3D echocardiography were performed before surgical repair of P2 prolapse in a single patient. A finite element model of the left ventricle and mitral valve was created previously, and the modeling program LS-DYNA was used to calculate leaflet stress for the following repairs: Triangular LR; LR with ring annuloplasty (LR + RA); One NC; Two NCs; and 2NC + RA. RESULTS: (1) NC placement resulted in stable posterior leaflet stress: Baseline versus 2 NC at end diastole (ED), 12.1 versus 12.0 kPa, at end systole (ES) 20.3 versus 21.7 kPa. (2) In contrast, LR increased posterior leaflet stress: Baseline versus LR at ED 12.1 versus 40.8 kPa, at ES 20.3 versus 46.1 kPa. (3) All repair types reduced anterior leaflet stress: Baseline versus 2 NC versus LR 34.2 versus 25.8 versus 20.6 kPa at ED and 80.8 versus 76.8 versus 67.8 kPa at ES. (4) The addition of RA reduced leaflet stress relative to repair without RA. CONCLUSIONS: Neochord repair restored normal leaflet coaptation without creating excessive leaflet stress, whereas leaflet resection more than doubled stress across the posterior leaflet. The excess stress created by leaflet resection was partially, but not completely, mitigated by ring annuloplasty.