A New Simple and Objective Method for Graft Sizing in Valve-Sparing Root Replacement Using the Reimplantation Technique

The methods of graft sizing in valve-sparing surgery are criticized for their complexity and subjectivity in application. We propose a simple method for graft sizing in valve-sparing root replacement using the reimplantation technique. Practically, the height of the commissure between the noncoronary cusp and the left coronary cusp give the size of the graft. This new method of graft sizing was successfully applied in the last 27 consecutive patients with good immediate results. Graft sizing with this objective and reproducible simple method results in restoration of normal aortic valve geometry and function

Phosphorylation and translocation of heat shock protein 27 and αB-crystallin in human myocardium after cardioplegia and cardiopulmonary bypass

ObjectivesCardiac surgery using cardioplegia and cardiopulmonary bypass subjects myocardium to hypothermic reversible ischemic injury that can impair cardiac function. Research in animal and cell models demonstrates that acute myocardial ischemia/reperfusion injury causes phosphorylation of heat shock protein 27 and αB-crystallin. Phosphorylation of heat shock protein 27 and αB-crystallin is implicated in the regulation of both beneficial and detrimental responses to ischemic injury. The phosphorylation status of these proteins in human myocardium after ischemic insults associated with cardioplegia and cardiopulmonary bypass is unknown.MethodsRight atrial appendage and chest wall skeletal muscle samples were collected from patients before and after cardioplegia and cardiopulmonary bypass. Cardioplegia and cardiopulmonary bypass-induced changes in phosphorylation and localization of heat shock protein 27 and αB-crystallin were determined using immunoblot and confocal microscopy with total and phospho-specific antibodies.ResultsCardioplegia and cardiopulmonary bypass increased the phosphorylation of heat shock protein 27 on serine 15, 78, and 82, and αB-crystallin on serine 59 and 45, but not serine 19. The majority of heat shock protein 27 and αB-crystallin localized to I-bands of cardiac myofilaments and shifted to a detergent insoluble fraction after cardioplegia and cardiopulmonary bypass. Cardioplegia and cardiopulmonary bypass–induced phosphorylation of specific heat shock protein 27 and αB-crystallin residues were associated with additional subcellular locations. Increases in phosphorylation of heat shock protein 27 and αB-crystallin were negatively correlated with cardiac function after surgery.ConclusionCardiac surgery using cardioplegia and cardiopulmonary bypass is associated with phosphorylation and myofilament translocation of heat shock protein 27 and αB-crystallin in human myocardium. Phosphorylation of specific heat shock protein 27 and αB-crystallin serine residues is associated with distinct localization. Understanding the human myocardial small heat shock protein response may have significant implications for surgical myocardial protection

Insulin treatment enhances the myocardial angiogenic response in diabetes

ObjectiveGrowth factor and cell-based angiogenesis are attractive therapeutic options for diabetic patients with end-stage coronary disease. Reduced collateral vessel formation observed in diabetes is associated with increased expression of anti-angiogenic proteins, angiostatin and endostatin. The aim of this study was to determine the effects of insulin treatment on the diabetic angiogenic response to chronic myocardial ischemia.MethodsYucatan miniswine were treated with alloxan (pancreatic β-cell specific toxin, 150 mg/kg) and divided into two groups. In the diabetic group (DM, n = 8), blood glucose levels were kept greater than 250 mg/dL, and in the insulin-treated group (IDM, n = 6), intramuscular insulin was administered daily to keep blood glucose less than 150 mg/dL. A third group of age-matched swine served as nondiabetic controls (ND; n = 8). Eight weeks later, all animals underwent circumflex artery ameroid constrictor placement to induce chronic ischemia. Myocardial perfusion was assessed at 3 and 7 weeks after ameroid placement using microspheres. Microvascular function, capillary density, and myocardial expression of anti-angiogenic mediators were evaluated.ResultsDiabetic animals exhibited significant impairments in endothelium-dependent microvessel relaxation to adenosine diphosphate and substance P, which were reversed in insulin-treated animals. Collateral-dependent perfusion in the ischemic circumflex territory, which was profoundly reduced in diabetic animals (−0.18 ± 0.02 vs +0.23 ± 0.07 mL · min−1 · g−1; P < .001), improved significantly with insulin treatment (0.12 ± 0.05 mL · min−1 · g−1; P < .01). Myocardial expression of anti-angiogenic proteins, angiostatin and endostatin, showing a 4.3- and 3.6-fold increase in diabetic animals respectively (both P < .01 vs ND), was markedly reduced in insulin-treated animals (2.3- and 1.8-fold vs ND; both P < .01).ConclusionsInsulin treatment successfully reversed diabetic coronary endothelial dysfunction and significantly improved the endogenous angiogenic response. These pro-angiogenic effects may be mediated through downregulation of anti-angiogenic mediators. Insulin therapy appears to be a promising modality to enhance the angiogenic response in diabetic patients

Aortic valve repair with patch in non-rheumatic disease: indication, techniques and durability†

OBJECTIVES: To analyse the long-term outcomes of aortic valve (AV) repair with biological patch in patient with non-rheumatic valve disease. METHODS: From 1995 to 2011, 554 patients underwent elective (AV) repair; among them, 57 (mean age 45 ± 17 years) had cusp restoration using patch for non-rheumatic valve disease. Seven (12%) patients had unicuspid valve, 30 (53%) patients had bicuspid valve and 20 (35%) had tricuspid valve. Autologous pericardium was used in 26 patients (7 treated, 19 non-treated), bovine pericardium in 26, autologous tricuspid valve leaflet in 4 and aortic homograft cusp in 1. Patching was used to repair perforation (n = 20, 35%), commissural defect (n = 18, 32%), raphe repair (n = 17, 30%) or for cusp extension (n = 2, 3.5%). Echocardiographic and clinical follow-up was 98% complete and mean follow-up was 72 ± 42.5 months. RESULTS: No hospital mortality. At 8 years, overall survival was 90 ± 5% and freedom from valve-related death was 96 ± 3%. Two patients (3.5%) needed early reoperation for aortic regurgitation (AR); they underwent re-repair and the Ross procedure, respectively. Late reoperation was necessary in 9 patients (16%) for AR (n = 4), stenosis (n = 3) or mixed disease (n = 2). They had the Ross procedure (n = 6) or prosthetic valve replacement (n = 3) with no mortality. At 8 years, freedom from reoperation was 75 ± 9%. Freedom from reoperation was slightly higher in tricuspid compared with non-tricuspid valves (92 ± 7 vs 68 ± 11%, P = 0.18) and slightly higher for bovine (95 ± 5%) compared with autologous pericardium (73 ± 11%, P = 0.38), but differences were statistically not significant. In tricuspid valves, freedom from reoperation was higher in perforation repair compared with other techniques (100 vs 50 ± 35%, P = 0.02). In bicuspid valves, freedom from reoperation was similar between different repair techniques (P = 0.38). Late echocardiography showed AR 0-1 in 30 (53%) patients, AR 2 in 12 (21%) and no AR ≥ 3. Three patients presented a mean transvalvular gradient of 30-40 mmHg. Thromboembolic events occurred in 2 patients (0.6%/patient-year), bleeding events in 1 (0.3% /patient-year) and no endocarditis occurred. CONCLUSIONS: AV repair with biological patch is feasible for various aetiologies. The techniques are safe and medium-term durability is acceptable, even excellent for perforation repair in tricuspid valve morphology. Bovine pericardium is a good alternative to autologous pericardium

The role of annular dimension and annuloplasty in tricuspid aortic valve repair†

OBJECTIVES: Valve sparing reimplantation can improve the durability of bicuspid aortic valve repair compared with subcommissural annuloplasty, especially in patients with a large basal ring. This study analyses the effect of basal ring size and annuloplasty on valve repair in the setting of a tricuspid aortic valve. METHODS: From 1995 to 2013, 382 patients underwent elective tricuspid aortic valve repair. We included only those undergoing subcommissural annuloplasty, valve sparing reimplantation or no annuloplasty and in whom intraoperative transoesophageal echocardiography images were available for retrospective pre- and post-repair basal ring measurements (n = 323, subcommissural annuloplasty: 146, valve sparing reimplantation: 154, no annuloplasty: 23). In a subgroup of patients with available echocardiographic images, basal ring was retrospectively measured at the latest follow-up or prior to reoperation. subcommissural annuloplasty and valve sparing reimplantation were compared after matching for degree of aortic regurgitation and root size. RESULTS: All three groups differed significantly for most of preoperative characteristics. Hospital mortality was 0.9%. The median follow-up was 4.7 years. At 8 years, overall survival was 80 ± 5%. Freedom from reoperation and freedom from aortic regurgitation >1+ were 92 ± 5% and 71 ± 8%, respectively. In multivariate analysis, predictors of aortic regurgitation >1+ were left ventricular end-diastolic diameter (P = 0.003), cusp repair (P = 0.006), body surface area (P = 0.01) and subcommissural annuloplasty (P = 0.05). In subcommissural annuloplasty, freedom from aortic regurgitation >1+ was lower for patients with basal ring ≥28 mm compared with patients with basal ring 1+ was independent of basal ring size (P = 0.38). In matched comparison between subcommissural annuloplasty and valve sparing reimplantation, freedom from aortic regurgitation >1+ was not significantly different (P = 0.06), but in patients with basal ring ≥28 mm, valve sparing reimplantation was superior to subcommissural annuloplasty (P = 0.04). Despite similar intraoperative reduction in basal ring size in subcommissural annuloplasty and valve sparing reimplantation, patients with subcommissural annuloplasty exhibited greater increase in basal ring size during the follow-up compared with the valve sparing reimplantation group (P < 0.001). CONCLUSIONS: As with a bicuspid aortic valve, a large basal ring predicts recurrence of aortic regurgitation in patients with tricuspid aortic valve undergoing repair with the subcommissural annuloplasty technique. This recurrence is caused by basal ring dilatation over time after subcommissural annuloplasty. With the valve sparing reimplantation technique, large basal ring did not predict aortic regurgitation recurrence, as prosthetic-based circumferential annuloplasty displayed better stability over time. Stable circumferential annuloplasty is recommended in tricuspid aortic valve repair whenever the basal ring size is ≥28 mm

The internal thoracic artery skeletonization study: A paired, within-patient comparison [NCT00265499]

BACKGROUND: Traditional harvesting of the internal thoracic artery (ITA) for use as a conduit in coronary bypass surgery involves the dissection of a rim of tissue surrounding the artery on either side. Recent studies, primarily observational, have suggested that skeletonization of the ITA can improve conduit flow, increase length, and reduce the risk of deep sternal infection in high risk patients. Furthermore, skeletonization of the ITA can potentially preserve intercostal nerves and reduce post-operative pain and dysesthesias associated with ITA harvesting. In order to assess the effects of ITA skeletonization, we report a prospective, randomized, within-patient study design that shares many features of a cross-over study. METHODS: Patients undergoing bilateral internal thoracic artery harvest will be randomized to having one side skeletonized and the other harvested in a non-skeletonized manner. Outcome measures include ITA flow and length measured intra-operatively, post-operative pain and dysesthesia, evaluated at discharge, four weeks, and three months post-operatively, and sternal perfusion assessed using single photon emission computed tomography. Harvest times as well as safety endpoints of ITA injury will be recorded. DISCUSSION: This study design, using within-patient comparisons and paired analyses, minimizes the variability of the outcome measures, which is seldom possible in the evaluation of surgical techniques, with minimal chance of carryover effects that can hamper the interpretation of traditional cross-over studies. This study will provide a valid evaluation of clinically relevant effects of internal thoracic artery skeletonization in improving outcomes following coronary artery bypass surgery