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Risk Factors For Sternal Breakdown in Cardiac Surgery Patients
478
Heart, Lung and Circulation 2013;22:455–489
2012 ANZSCTS Annual Scientific Meeting
ABSTRACTS
Table 1. Cardiac MRI parameters in the complicated and uncomplicated groups (Mean ± SEM p < 0.05). CMR parameters LVEF (%)
Complicated (n = 10)
Uncomplicated (n = 21)
30 ± 2
37 ± 2
2.57 ± 0.2
2.93 ± 0.2
LV scar burden (% of myocardial mass)
19 ± 1
7±2
RVEF (%)
41 ± 5
52 ± 2
91 ± 7
71 ± 4
Cl
(L/min/m3 )
RVEDVi
(mL/m2 )
Fig. 1. Contrast CMR of a patient with ICM showing infero-postehor transmural infarction (incl. post, papillary muscle).
Introduction: • Risk scoring in coronary artery bypass surgery (e.g. euroSCORE) may lack the specificity to accurately predict outcomes in high-risk patients. • Cardiac magnetic resonance imaging (CMR) is a non-invasive method of examining myocardial volumes, function, and viability using delayed enhancement with higher spatial resolution, larger fields of view, unrestricted imaging planes, and lower operator dependency compared to conventional imaging modalities. • We sought to establish if parameters derived from preoperative CMR correlate with short-term outcomes in patients undergoing high-risk coronary artery graft surgery (CAGS). Methods: • Thirty-one (31) consecutive patients with high euroSCORE (22 ± 4) and low EF (38% ± 2) who underwent CAGS and in whom contrast CMR (1.5 T) was performed preoperatively were retrospectively recruited into the study. • CMR parameters were recorded and clinical data such as bypass time, ionotropic requirement, time in ICU, and major complications associated with surgery were noted (i.e. mortality, MACCE, prolonged intubation, renal failure requiring haemodialysis). • Ten (10) patients were identified as having a complicated postoperative course (i.e. two or more organ related or surgical complications, ICU admission > 4 days, mortality). Results • EuroSCOREs were similar between the complicated and uncomplicated groups (22 ± 5 vs. 25 ± 4 respectively, p = 0.96) (Fig. 1; Table 1). • CMR analysis showed that patients in the complicated group had: • Lower left ventricular ejection fraction (LVEF) compared to the uncomplicated group (30 ± 2% vs. 37 ± 2%, p < 0.05) • Lower Cl (2.57 ± 0.2 vs. 2.93 ± 0.2 L/min/m3 , p < 0.05) • Greater LV scar burden (19 ± 1% vs 7 ± 2% of myocardial mass, p < 0.05) • Lower RVEF (41 ± 5% vs 52 ± 2, p < 0.05) • Greater indexed right ventricular end-diastolic volume (RVEDVi; 91 ± 7 vs 71 ± 4 mL/m2 , p < 0.05)
Conclusions: • Some CMR parameters correlate with early postoperative outcomes in high-risk CAGS patients. • CMR may be a valuable adjunct to clinical and other risk assessment tools and may improve patient selection in high-risk CAGS. ANZSCTSASM 2012 http://dx.doi.org/10.1016/j.hlc.2013.03.050 2012 Poster Presentation/Panel 25 Risk Factors For Sternal Breakdown in Cardiac Surgery Patients Jivesh Choudhary, Sarah Gabriel, James McGree, Muslim Mustaev, Yasangi Ranawaka, Peter Tesar The Prince Charles Hospital, Brisbane, Australia Introduction: Sternal wound infections and delayed sternal wound healing, following open heart surgery are an infrequent occurrence, but can have significant impact on patient morbidity, length of stay, and cost of care. These potentially life-threatening complications occur in up to 1–5% of patients following cardiac surgery. The aim of the study was to identify the risk factors for sternal wound dehiscence in cardiac surgical patients to identify future patients who may benefit from the use of a sternal fixation device. Methods: The cardiac surgical database identified 1086 patients who underwent cardiac surgery through full median sternotomy, including heart transplantation, at the Prince Charles Hospital from January to December 2011. Twenty-three patients required surgical repair of the sternum due to sternal wound breakdown. The remaining 1063 patients without sternal wound complications composed the non-breakdown group. The patients’ pre-operative risk factors, perioperative data and variables and post operative morbidities were analysed. An initial exploratory analysis was conducted using variable plots and summary statistics to identify common risk factors. Data analysis was performed investigating the relationship between breakdown (binary response) and the explanatory variables via the logistic regression model. Given there were a large number of possibly influential explanatory variables, a variable selection procedure was used to determine which variables were important. All
computation was performed in the R-package statistical software, version 2.13. Results: Of the treatment group requiring surgical repair of the sternum, 15 were males and eight were females. The mean age of the patients was 67.1 ± 10.6 years (62.1 ± 15.6 years in the non-breakdown group). The mean body mass index (BMI) in the breakdown and nonbreakdown groups was 31.3 ± 4.6 and 28.2 ± 5.3 kg/m2 , respectively. The risk factors for breakdown of the sternum were identified as: previous surgery for peripheral vascular disease (PVD) (p = 0.027); operations involving aortic wall reconstruction (AW) (p = 0.021); heart transplantation (HTx) (p = 0.010); family history of ischaemic heart disease (FHIHD) (p = 0.02); severe respiratory disease (RD) (p = 1.08e−06); BMI (p = 0.005); and harvesting left internal mammary artery (LIMA) (p = 0.0006). The odds ratios (95% CI) of breakdown in the patients with previous surgery for PVD was 4.92 (2.39–10.16), AW 5.27 (2.57–10.82), HTx 20.69 (6.34–67.53), FHIHD 4.06 (2.22–7.42), severe RD 36.95 (17.63–77.46), BMI 1.12 (1.08–1.17), LIMA 4.58 (2.95–7.12). Notably, the probability of the sternal breakdown was estimated to be 20 times higher in the patients having had HTx and 37 times higher in the patients having severe RD (FVC < 40%) and 1.12 times higher for every unit increase of BMI. Discussion: Seven perioperative risk factors were identified which may affect natural course of the sternal wound healing leading to breakdown of the sternum. These patients should undergo thorough review preoperatively. A special attention should be paid while closing the chest of those patients involving application of sternal fixating devices. http://dx.doi.org/10.1016/j.hlc.2013.03.051 2012 Poster Presentation/Panel 26 Early Experience of Transcatheter Aortic Valve Implantation Through Ascending Aorta Kan Nawata ∗ , Robert G. Stuklis, Joseph K. Montarello, Stephen Worthley D’Arcy Sutherland Cardiothoracic Surgical Unit, Department of Cardiology, Royal Adelaide Hospital, Adelaide, SA, Australia Introduction: Transcatheter aortic valve implantation has emerged and rapidly gained credibility as a useful alternative to treat patients with inoperable aortic stenosis. By their nature these patients often have severe peripheral arteriopathy which precludes the transfemoral or subclavian approach. Transcatheter aortic valve implantation via ascending aortic approach was first reported in 2009 by Bauernschmitt et al. (CoreValve) and in 2010 by Bapat (SAPIEN valve) as an alternative option for no-access patients. Our institute conducted an initial cohort of four patients and we present the outcomes here. Methods: Four patients underwent transcatheter aortic valve implantation through the ascending aorta via a mini-sternotomy in three cases, and one via a right anterior mini-thoracotomy. Procedures were performed under general anesthesia using angiographic and
2012 ANZSCTS Annual Scientific Meeting
479
trans-oesophageal echocardiogram guidance. The team consisted of two interventional cardiologists and one cardiac surgeon. Results: Mean age was 85 years (± 6 years) and mean euroSCORE was 14%. For all the cases, satisfactory surgical exposure of the distal ascending aorta was obtained. Procedural success was 100% with trivial paravalvular leak in three cases and no leak in one case. Post-operatively mean ICU length of stay was 10.5 days. Three patients developed acute renal failure and three required reintubation or non-invasive ventilation. One of them died of metabolic acidosis due to intestinal ischaemia on day 10. One patient had acute liver dysfunction and one patient required the implantation of a permanent pacemaker. One patient was transferred to a rehabilitation hospital and the others remain inpatients. Conclusions: Partial sternotomy and mini-thoracotomy via 1st intercostal space gave an excellent surgical field for transcatheter aortic valve implantation through distal ascending aortic puncture for patients without suitable percutaneous access. Considering their preoperative high risk background, careful postoperative monitoring of renal function and respiratory status is of importance, even if procedure itself is uneventful. The impact of partial sternotomy in this cohort should not be underestimated. http://dx.doi.org/10.1016/j.hlc.2013.03.052 2012 Poster Presentation/Panel 27 Surgical Palliation in Single Ventricle Patients with Dextrocardia Chin Poh ∗ , Mary Xu, John C. Galetti, Ajay Iyengar, Michael Cheung, Christian P. Brizard, Igor E. Konstantinov, Yves d’Udekem Background: Dextrocardia is found in a significant proportion of patients undergoing a single-ventricle repair. Surgical outcomes in this cohort are unclear. Methods: The records of all consecutive 41 patients with single ventricle physiology and dextrocardia were reviewed. Of this cohort, 19 patients had heterotaxy syndrome. Twenty-five of the 41 patients had atrio-ventricular valve regurgitation (AVVR) on presentation (mild: 13; moderate: nine; severe: three). Results: Of the 41 patients, one patient died before intervention. Initial surgical palliation was performed in 31 patients. Four patients died post-operatively and four interim deaths occurred between initial palliation and BCPS. Thirty of the surviving 32 patients underwent BCPS, with two peri-operative deaths. There were four interim deaths before Fontan surgery. Twenty-two of the surviving 25 patients underwent Fontan procedure. There was one post-operative mortality. Survival to the age of 15 years was 56% (95% CI: 39–70%). Patients with moderate or severe regurgitation had higher mortality if they were managed conservatively rather than by surgery (5/6 vs 2/6). Patients with bilateral BCPS had better operative outcomes and survival compared to peers with unilateral anastomosis (OR = 27; p = 0.005; 95% CI: 2.7–269).
ABSTRACTS
Heart, Lung and Circulation 2013;22:455–489
Heart, Lung and Circulation 2013;22:455–489
2012 ANZSCTS Annual Scientific Meeting
ABSTRACTS
Table 1. Cardiac MRI parameters in the complicated and uncomplicated groups (Mean ± SEM p < 0.05). CMR parameters LVEF (%)
Complicated (n = 10)
Uncomplicated (n = 21)
30 ± 2
37 ± 2
2.57 ± 0.2
2.93 ± 0.2
LV scar burden (% of myocardial mass)
19 ± 1
7±2
RVEF (%)
41 ± 5
52 ± 2
91 ± 7
71 ± 4
Cl
(L/min/m3 )
RVEDVi
(mL/m2 )
Fig. 1. Contrast CMR of a patient with ICM showing infero-postehor transmural infarction (incl. post, papillary muscle).
Introduction: • Risk scoring in coronary artery bypass surgery (e.g. euroSCORE) may lack the specificity to accurately predict outcomes in high-risk patients. • Cardiac magnetic resonance imaging (CMR) is a non-invasive method of examining myocardial volumes, function, and viability using delayed enhancement with higher spatial resolution, larger fields of view, unrestricted imaging planes, and lower operator dependency compared to conventional imaging modalities. • We sought to establish if parameters derived from preoperative CMR correlate with short-term outcomes in patients undergoing high-risk coronary artery graft surgery (CAGS). Methods: • Thirty-one (31) consecutive patients with high euroSCORE (22 ± 4) and low EF (38% ± 2) who underwent CAGS and in whom contrast CMR (1.5 T) was performed preoperatively were retrospectively recruited into the study. • CMR parameters were recorded and clinical data such as bypass time, ionotropic requirement, time in ICU, and major complications associated with surgery were noted (i.e. mortality, MACCE, prolonged intubation, renal failure requiring haemodialysis). • Ten (10) patients were identified as having a complicated postoperative course (i.e. two or more organ related or surgical complications, ICU admission > 4 days, mortality). Results • EuroSCOREs were similar between the complicated and uncomplicated groups (22 ± 5 vs. 25 ± 4 respectively, p = 0.96) (Fig. 1; Table 1). • CMR analysis showed that patients in the complicated group had: • Lower left ventricular ejection fraction (LVEF) compared to the uncomplicated group (30 ± 2% vs. 37 ± 2%, p < 0.05) • Lower Cl (2.57 ± 0.2 vs. 2.93 ± 0.2 L/min/m3 , p < 0.05) • Greater LV scar burden (19 ± 1% vs 7 ± 2% of myocardial mass, p < 0.05) • Lower RVEF (41 ± 5% vs 52 ± 2, p < 0.05) • Greater indexed right ventricular end-diastolic volume (RVEDVi; 91 ± 7 vs 71 ± 4 mL/m2 , p < 0.05)
Conclusions: • Some CMR parameters correlate with early postoperative outcomes in high-risk CAGS patients. • CMR may be a valuable adjunct to clinical and other risk assessment tools and may improve patient selection in high-risk CAGS. ANZSCTSASM 2012 http://dx.doi.org/10.1016/j.hlc.2013.03.050 2012 Poster Presentation/Panel 25 Risk Factors For Sternal Breakdown in Cardiac Surgery Patients Jivesh Choudhary, Sarah Gabriel, James McGree, Muslim Mustaev, Yasangi Ranawaka, Peter Tesar The Prince Charles Hospital, Brisbane, Australia Introduction: Sternal wound infections and delayed sternal wound healing, following open heart surgery are an infrequent occurrence, but can have significant impact on patient morbidity, length of stay, and cost of care. These potentially life-threatening complications occur in up to 1–5% of patients following cardiac surgery. The aim of the study was to identify the risk factors for sternal wound dehiscence in cardiac surgical patients to identify future patients who may benefit from the use of a sternal fixation device. Methods: The cardiac surgical database identified 1086 patients who underwent cardiac surgery through full median sternotomy, including heart transplantation, at the Prince Charles Hospital from January to December 2011. Twenty-three patients required surgical repair of the sternum due to sternal wound breakdown. The remaining 1063 patients without sternal wound complications composed the non-breakdown group. The patients’ pre-operative risk factors, perioperative data and variables and post operative morbidities were analysed. An initial exploratory analysis was conducted using variable plots and summary statistics to identify common risk factors. Data analysis was performed investigating the relationship between breakdown (binary response) and the explanatory variables via the logistic regression model. Given there were a large number of possibly influential explanatory variables, a variable selection procedure was used to determine which variables were important. All
computation was performed in the R-package statistical software, version 2.13. Results: Of the treatment group requiring surgical repair of the sternum, 15 were males and eight were females. The mean age of the patients was 67.1 ± 10.6 years (62.1 ± 15.6 years in the non-breakdown group). The mean body mass index (BMI) in the breakdown and nonbreakdown groups was 31.3 ± 4.6 and 28.2 ± 5.3 kg/m2 , respectively. The risk factors for breakdown of the sternum were identified as: previous surgery for peripheral vascular disease (PVD) (p = 0.027); operations involving aortic wall reconstruction (AW) (p = 0.021); heart transplantation (HTx) (p = 0.010); family history of ischaemic heart disease (FHIHD) (p = 0.02); severe respiratory disease (RD) (p = 1.08e−06); BMI (p = 0.005); and harvesting left internal mammary artery (LIMA) (p = 0.0006). The odds ratios (95% CI) of breakdown in the patients with previous surgery for PVD was 4.92 (2.39–10.16), AW 5.27 (2.57–10.82), HTx 20.69 (6.34–67.53), FHIHD 4.06 (2.22–7.42), severe RD 36.95 (17.63–77.46), BMI 1.12 (1.08–1.17), LIMA 4.58 (2.95–7.12). Notably, the probability of the sternal breakdown was estimated to be 20 times higher in the patients having had HTx and 37 times higher in the patients having severe RD (FVC < 40%) and 1.12 times higher for every unit increase of BMI. Discussion: Seven perioperative risk factors were identified which may affect natural course of the sternal wound healing leading to breakdown of the sternum. These patients should undergo thorough review preoperatively. A special attention should be paid while closing the chest of those patients involving application of sternal fixating devices. http://dx.doi.org/10.1016/j.hlc.2013.03.051 2012 Poster Presentation/Panel 26 Early Experience of Transcatheter Aortic Valve Implantation Through Ascending Aorta Kan Nawata ∗ , Robert G. Stuklis, Joseph K. Montarello, Stephen Worthley D’Arcy Sutherland Cardiothoracic Surgical Unit, Department of Cardiology, Royal Adelaide Hospital, Adelaide, SA, Australia Introduction: Transcatheter aortic valve implantation has emerged and rapidly gained credibility as a useful alternative to treat patients with inoperable aortic stenosis. By their nature these patients often have severe peripheral arteriopathy which precludes the transfemoral or subclavian approach. Transcatheter aortic valve implantation via ascending aortic approach was first reported in 2009 by Bauernschmitt et al. (CoreValve) and in 2010 by Bapat (SAPIEN valve) as an alternative option for no-access patients. Our institute conducted an initial cohort of four patients and we present the outcomes here. Methods: Four patients underwent transcatheter aortic valve implantation through the ascending aorta via a mini-sternotomy in three cases, and one via a right anterior mini-thoracotomy. Procedures were performed under general anesthesia using angiographic and
2012 ANZSCTS Annual Scientific Meeting
479
trans-oesophageal echocardiogram guidance. The team consisted of two interventional cardiologists and one cardiac surgeon. Results: Mean age was 85 years (± 6 years) and mean euroSCORE was 14%. For all the cases, satisfactory surgical exposure of the distal ascending aorta was obtained. Procedural success was 100% with trivial paravalvular leak in three cases and no leak in one case. Post-operatively mean ICU length of stay was 10.5 days. Three patients developed acute renal failure and three required reintubation or non-invasive ventilation. One of them died of metabolic acidosis due to intestinal ischaemia on day 10. One patient had acute liver dysfunction and one patient required the implantation of a permanent pacemaker. One patient was transferred to a rehabilitation hospital and the others remain inpatients. Conclusions: Partial sternotomy and mini-thoracotomy via 1st intercostal space gave an excellent surgical field for transcatheter aortic valve implantation through distal ascending aortic puncture for patients without suitable percutaneous access. Considering their preoperative high risk background, careful postoperative monitoring of renal function and respiratory status is of importance, even if procedure itself is uneventful. The impact of partial sternotomy in this cohort should not be underestimated. http://dx.doi.org/10.1016/j.hlc.2013.03.052 2012 Poster Presentation/Panel 27 Surgical Palliation in Single Ventricle Patients with Dextrocardia Chin Poh ∗ , Mary Xu, John C. Galetti, Ajay Iyengar, Michael Cheung, Christian P. Brizard, Igor E. Konstantinov, Yves d’Udekem Background: Dextrocardia is found in a significant proportion of patients undergoing a single-ventricle repair. Surgical outcomes in this cohort are unclear. Methods: The records of all consecutive 41 patients with single ventricle physiology and dextrocardia were reviewed. Of this cohort, 19 patients had heterotaxy syndrome. Twenty-five of the 41 patients had atrio-ventricular valve regurgitation (AVVR) on presentation (mild: 13; moderate: nine; severe: three). Results: Of the 41 patients, one patient died before intervention. Initial surgical palliation was performed in 31 patients. Four patients died post-operatively and four interim deaths occurred between initial palliation and BCPS. Thirty of the surviving 32 patients underwent BCPS, with two peri-operative deaths. There were four interim deaths before Fontan surgery. Twenty-two of the surviving 25 patients underwent Fontan procedure. There was one post-operative mortality. Survival to the age of 15 years was 56% (95% CI: 39–70%). Patients with moderate or severe regurgitation had higher mortality if they were managed conservatively rather than by surgery (5/6 vs 2/6). Patients with bilateral BCPS had better operative outcomes and survival compared to peers with unilateral anastomosis (OR = 27; p = 0.005; 95% CI: 2.7–269).
ABSTRACTS
Heart, Lung and Circulation 2013;22:455–489