Aortic root replacement with Medtronic Freestyle bioprosthesis: 25-year experience.

BACKGROUND: Stentless porcine bioprothesis is a surgical strategy to treat aortic root disease. Use has been limited due to the concern for long-term valve degeneration. This study evaluated the perioperative and late outcomes of patients with aortic root disease requiring root replacement. METHODS: A total of 409 patients underwent aortic root replacement by a single surgeon using a stentless porcine bioroot between February 1996 and May 2020. The cohort was divided into two groups (age ≤65 and >65 years). Descriptive statistics were used to analyze the data and Kaplan-Meier curves used to evaluate long-term outcomes. RESULTS: Patients age >65 years were more likely to be female (p = .01), have hypertension (p = .01), require circulatory arrest (p = .01), and have concomitant coronary artery bypass grafting (CABG) (p = .04). Baseline creatinine >1.8 (p = .20), diabetes (p = .06), and ejection fraction (p = .20) were similar between groups. The 1-, 5-, and 10-year survival for patients age ≤65 years were 92%, 87%, and 69%, respectively, significantly better than patients age >65 (88%, 73%, and 43%, respectively) (p < .01, Figure 1). The 1-, 5-, and 10-year freedom from reoperation for patients ≤65 years were 99%, 97%, and 93% versus 99%, 98%, and 96% in patients age >65 years, respectively (p = .24). CONCLUSION: Patients with aortic root disease can be treated with acceptable perioperative outcomes, long-term survival, and low reoperation rates using a stentless porcine bioprothesis. It should be considered irrespective of age due to its excellent durability and freedom from anti-coagulation requirement.

Risk Factors and Outcomes in Redo Coronary Artery Bypass Grafting.

BACKGROUND: Reoperative coronary artery bypass grafting (redo-CABG) has declined during the last decade, while use of percutaneous coronary intervention (PCI) has increased. The aim of this retrospective study was to evaluate risk factors, in-hospital mortality, and long-term survival between first-time CABG and redo-CABG. METHODS: From January 2009 to December 2015, 2,581 patients underwent first-time CABG procedures while 132 underwent isolated redo-CABG. Logistic regression was used to identify risk factors predictive of redo-CABG and after propensity matching the in-hospital morbidity and long-term all-cause mortality were compared. RESULTS: Risk factors for redo-CABG were prior PCI, dyslipidaemia, diabetes and hypertension. After propensity matching there were no significant differences between the redo-CABG (n = 126) and first-time CABG groups (n = 232) in baseline characteristics. The adjusted in-hospital mortality was 3.1% for redo-CABG and 2.1% for first-time CABG (p = 0.55). Redo-CABG required significantly more intraoperative red blood cells (p = 0.03), platelets (p < 0.001), cryoprecipitate (p < 0.007) and fresh frozen plasma (p < 0.001) than first-time CABG. There was no significant difference in reoperation for bleeding (p = 0.72), prolonged ventilation (p = 0.98), postoperative stroke (p = 0.92) or dialysis (p = 0.44). The survival at 1, 3 and 5 years for redo-CABG was 93.5%, 90%, and 85% respectively, and 95.5%, 94.5%, 93% for first-time CABG, respectively (p = 0.2). CONCLUSIONS: Prior PCI after first time CABG and the risk factors for atherosclerotic disease are predictive for redo-CABG. An increased use of blood products is required during redo-CABG. After propensity matching, in-hospital mortality and long-term survival for redo-CABG is comparable to first-time operation. Re-sternotomy does not impact the survival in redo-CABG.

Effect of the stop-flow technique on cardiac retention of c-kit positive human cardiac stem cells after intracoronary infusion in a porcine model of chronic ischemic cardiomyopathy.

It is commonly thought that the optimal method for intracoronary administration of cells is to stop coronary flow during cell infusion, in order to prolong cell/vascular wall contact, enhance adhesion, and promote extravasation of cells into the interstitial space. However, occlusion of a coronary artery with a balloon involves serious risks of vascular damage and/or dissection, particularly in non-stented segments such as those commonly found in patients with heart failure. It remains unknown whether the use of the stop-flow technique results in improved donor cell retention. Acute myocardial infarction was produced in 14 pigs. One to two months later, pigs received 10 million indium-111 oxyquinoline (oxine)-labeled c-kit(pos) human cardiac stem cells (hCSCs) via intracoronary infusion with (n = 7) or without (n = 7) balloon inflation. Pigs received cyclosporine to prevent acute graft rejection. Animals were euthanized 24 h later and hearts harvested for radioactivity measurements. With the stop-flow technique, the retention of hCSCs at 24 h was 5.41 ± 0.80 % of the injected dose (n = 7), compared with 4.87 ± 0.62 % without coronary occlusion (n = 7), (P = 0.60). When cells are delivered intracoronarily in a clinically relevant porcine model of chronic ischemic cardiomyopathy, the use of the stop-flow technique does not result in greater myocardial cell retention at 24 h compared with non-occlusive infusion. These results have practical implications for the design of cell therapy trials. Our observations suggest that the increased risk of complications secondary to coronary manipulation and occlusion is not warranted.

Cannula Placement for Cerebral Protection Without Circulatory Arrest in Patients Undergoing Hemiarch Aortic Aneurysm Repair.

BACKGROUND: Aortic aneurysms involving the proximal aortic arch, which require hemiarch-type repair, typically require circulatory arrest with antegrade cerebral perfusion. Left carotid antegrade cerebral perfusion (LCP) via distal arch cannulation without circulatory arrest was used in this study's patient population. The goal was to assess the operative efficiency and clinical outcomes of using a distal arch cannulation technique that would not require any hypothermic circulatory arrest (HCA) time compared with more traditional brachiocephalic artery cannulation with right-sided unilateral antegrade cerebral perfusion (RCP) and HCA. METHODS: A single-center retrospective review of patients with replacement of the distal ascending aorta involving the proximal arch was performed. Patients with an intramural hematoma or dissection were excluded. Between January 2015 and December 2019, 68 adult patients had undergone a hemiarch repair because of aneurysmal disease. Analysis of baseline demographics, operative data, and clinical outcomes was performed. RESULTS: Comparing the 68 patients: 21 patients were treated with RCP (via brachiocephalic artery graft with HCA), and 47 patients were treated with LCP (via distal aortic arch cannulation with cross-clamp between the brachiocephalic and left common carotid arteries without HCA). Baseline characteristics and outcomes were evaluated for both groups. The LCP group was younger (LCP median [IQR] age, 60 [53-65] years vs RCP median [IQR] age, 67 [59-71] years]. Sex, race, body mass index, comorbidities, and ejection fraction were similar between the groups. Cardiopulmonary bypass time (LCP, 123 minutes vs RCP, 149 minutes) and unilateral cerebral perfusion time (LCP, 17 minutes vs RCP, 22 minutes) were longer in the RCP group. Bleeding, prolonged ventilatory support, kidney failure, and length of stay were similar. In-hospital mortality was 2% in the LCP group vs 0% in the RCP group. Stroke occurred in 2 patients (4.2%) in the LCP group and in 0% of the RCP group. Mortality at 6 months in the LCP and RCP groups was 3% and 10%, respectively. CONCLUSION: Distal arch cannulation with LCP without HCA is a reasonable and safe alternative strategy for patients requiring hemiarch replacement for aneurysmal disease. This technique may provide additional benefits by avoiding circulatory arrest in these complex cases.

Early and midterm outcomes following surgery for acute type A aortic dissection.

OBJECTIVE: Surgical repair of acute Type A aortic dissection (AADA) is still associated with high in-hospital mortality. We evaluated the impact of perioperative risk factors on early and midterm survival. METHODS: Retrospective (2002-2011) database analysis at a single institution of 132 consecutive AADA patients (88 male, age 59.8 ± 13.6). All but five patients underwent repair with open distal anastomoses and hypothermic circulatory arrest: aortic valve replacement/root replacement (n=44, 33.3%) and valve re-suspension/repair (n=88, 66.7%). Ascending aorta, hemi-arch, and total arch repairs were performed in 11, 113, and eight patients, respectively. Antegrade and retrograde cerebral perfusion were used in all but six patients. RESULTS: Overall in-hospital mortality was 17.4% (n=23). Actuarial survival at one, five, and eight years was 82%, 72%, and 62%, respectively. Perfusion time (cardiopulmonary bypass) (226.5 ± 71.3 vs. 177.5 ± 51.7, p=0.0002), aortic cross-clamp time (min) (132.8 ± 45.7 vs. 109.8 ± 41.2, p=0.01), aortic arch (T2) tear (31% vs. 14%, p=0.03), instability (26% vs. 11%, p=0.02), postoperative stroke (38% vs. 14%, p=0.009), and low cardiac output (50% vs. 15%, p=0.04) all correlated with increased perioperative mortality. A Cox proportional hazard model showed perfusion time (hazard ratio [HR]=1.01), postoperative stroke (HR=2.73), age (HR=1.03), and unstability (HR=1.8) as significant risk factors (p<0.05) affecting the overall survival. CONCLUSION: There is a modern trend towards improving overall perioperative outcomes after surgical repair of AADA; however, early mortality and morbidity remain high even in aortic surgery referral centers.

Inflammatory aneurysms of the ascending aorta: diagnosis and surgical treatment.

Inflammatory aortic aneurysms (IAAs) are rare and located mainly in the infra-renal abdominal aorta. The ascending aorta has been typically spared from this process. We report on two cases of ascending aortic inflammatory aneurysms and describe the available literature on this rare entity.

Dual Left Main Coronary Arteries With Ischemia and Coronary Steal.

A 59-year-old man had angina and an abnormal perfusion scan. Work-up revealed 2 left main coronary arteries: the anomalous artery originated from the right coronary cusp and took an aberrant interventricular septal course; the other artery was atretic. He underwent surgical unroofing, with resolution of symptoms. (Level of Difficulty: Intermediate.).

Optimum surgical treatment for tricuspid valve infective endocarditis: An analysis of the Society of Thoracic Surgeons national database.

OBJECTIVE: The incidence of intravenous drug-associated tricuspid valve endocarditis in the United States is rapidly increasing. Our goal was to evaluate the outcomes of isolated tricuspid valve operations using the Society of Thoracic Surgeon Adult Cardiac Surgical Database. METHODS: From July 2011 to December 2016, 1613 patients with intravenous drug-associated tricuspid valve endocarditis underwent isolated tricuspid valve operations for endocarditis. Patients were stratified on the basis of type of tricuspid valve operation: valvectomy in 119 (7%), repair in 532 (33%), and replacement in 962 (60%). Risk factors and 30-day outcomes were compared among groups using Kruskal-Wallis and Pearson's chi-square tests. Multivariable logistic regression evaluated risk-adjusted operative mortality and morbidity by operative technique. RESULTS: Age, gender, race, and renal function were comparable among groups. Compared with the repair and replacement groups, the valvectomy group had a higher rate of acute infection (90% vs 79%, 84%; P < .01), Model for End-Stage Liver Disease score (10.17 vs 8.44, 9.74, P < .01), and urgent/emergency surgery (91% vs 75%, 83%; P < .01), respectively. Operative mortality was higher in those undergoing valvectomy (16%) (P < .01) compared with repair (2%) or replacement (3%). After risk adjustment, valvectomy was associated with a higher risk of operative mortality compared with repair (odds ratio, 3.82; P < .01), whereas there was no difference in operative mortality between repair and replacement (odds ratio, 0.95; P = .89). CONCLUSIONS: This contemporary series of intravenous drug-associated tricuspid valve endocarditis reveals that valvectomy is an independent predictor of operative mortality. When anatomically possible, repair should be the preferred management for tricuspid valve endocarditis to avoid recurrent valve infection and prosthetic valve degeneration.

Is internal mammary artery graft beneficial in emergent coronary artery bypass surgery? A Society of Thoracic Surgeons national database analysis.

BACKGROUND: Often, only saphenous vein grafts (SVGs) are used in emergent coronary artery bypass graft (CABG) procedures to provide quicker myocardial revascularization despite its lower long-term patency relative to the internal mammary artery (IMA) grafts. We examined differences between IMA and non-IMA graft recipients in emergent CABGs and its impact on in-hospital outcomes. METHODS: Retrospective review of Society of Thoracic Surgeon National Database was done to identify patients age ≥18 years undergoing primary emergent isolated CABG between 2013 and 2016. Emergent salvage, non-LAD disease, subclavian stenosis and revascularization with other arterial grafts were excluded. The study population was divided in two groups: IMA and non-IMA groups. Demographics, preoperative, intraoperative factors and postoperative outcomes were analyzed between the groups. RESULTS: Of 18,280 emergent CABGs during the study period, 16281 had IMA used and 1999 had only vein grafts. The IMA group was younger, more likely to be male, had lower creatinine and higher ejection fraction. The non-IMA and IMA groups were then propensity risk matched with ratio of 1:2 which showed significantly higher in-hospital mortality in the non-IMA group (15% vs. 7%, P<0.0001). The non-IMA groups also had higher rates bleeding (5% vs. 3%, P<0.01), renal failure (10% vs.6%, P<0.0001) and prolonged vent (44% vs. 30%, P<0.0001). CONCLUSIONS: IMA grafts in primary isolated emergent CABGs are associated with significantly lower rates of in-hospital mortality. Even for emergent CABG there may be a clinical benefit in using IMA grafts rather than SVGs only.

Alternative surgical strategy for the treatment of a mycotic aortic arch aneurysm.

We report the case of a 69-year-old man who presented with a symptomatic mycotic aneurysm of the aortic arch. Diagnosis was confirmed by positron emission tomography and by blood cultures positive for Salmonella species. A complete resection of the aortic arch process was performed via left thoracotomy using a cryopreserved aortic homograft and normothermic left heart bypass. The left-sided cerebral vessels were clamped, and adequacy of collateral left brain flow and oxygenation was confirmed by neurophysiologic monitoring. Using this less-invasive operative strategy, we avoided the risks inherent to deep hypothermic circulatory arrest and the use of prosthetic materials.

Safety of intracoronary infusion of 20 million C-kit positive human cardiac stem cells in pigs.

BACKGROUND: There is mounting interest in using c-kit positive human cardiac stem cells (c-kit(pos) hCSCs) to repair infarcted myocardium in patients with ischemic cardiomyopathy. A recent phase I clinical trial (SCIPIO) has shown that intracoronary infusion of 1 million hCSCs is safe. Higher doses of CSCs may provide superior reparative ability; however, it is unknown if doses >1 million cells are safe. To address this issue, we examined the effects of 20 million hCSCs in pigs. METHODS: Right atrial appendage samples were obtained from patients undergoing cardiac surgery. The tissue was processed by an established protocol with eventual immunomagnetic sorting to obtain in vitro expanded hCSCs. A cumulative dose of 20 million cells was given intracoronarily to pigs without stop flow. Safety was assessed by measurement of serial biomarkers (cardiac: troponin I and CK-MB, renal: creatinine and BUN, and hepatic: AST, ALT, and alkaline phosphatase) and echocardiography pre- and post-infusion. hCSC retention 30 days after infusion was quantified by PCR for human genomic DNA. All personnel were blinded as to group assignment. RESULTS: Compared with vehicle-treated controls (n=5), pigs that received 20 million hCSCs (n=9) showed no significant change in cardiac function or end organ damage (assessed by organ specific biomarkers) that could be attributed to hCSCs (P>0.05 in all cases). No hCSCs could be detected in left ventricular samples 30 days after infusion. CONCLUSIONS: Intracoronary infusion of 20 million c-kit positive hCSCs in pigs (equivalent to ~40 million hCSCs in humans) does not cause acute cardiac injury, impairment of cardiac function, or liver and renal injury. These results have immediate translational value and lay the groundwork for using doses of CSCs >1 million in future clinical trials. Further studies are needed to ascertain whether administration of >1 million hCSCs is associated with greater efficacy in patients with ischemic cardiomyopathy.

Cerebral oximetry for cardiac and vascular surgery.

The technology of transcranial near-infrared spectroscopy (NIRS) for the measurement of cerebral oxygen balance was introduced 25 years ago. Until very recently, there has been only occasional interest in its use during surgical monitoring. Now, however, substantial technologic advances and numerous clinical studies have, at least partly, succeeded in overcoming long-standing and widespread misunderstanding and skepticism regarding its value. Our goals are to clarify common misconceptions about near-infrared spectroscopy and acquaint the reader with the substantial literature that now supports cerebral oximetric monitoring in cardiac and major vascular surgery.

Clinical outcome after triple-valve operations in the modern era: are elderly patients at increased surgical risk?

BACKGROUND: Despite modern advances in surgical care, triple-valve surgery (TVS) remains a challenge and carries a mortality of 10% to 20%. No validated risk score is available for TVS, and the effect of advanced age is unknown. This study examined our results in the modern era with the aim of identifying perioperative predictors of adverse outcomes. METHODS: Between 1997 and 2013, 131 patients (mean age, 67.2±13.4 years) underwent TVS at our institution. Sixty-eight patients (51.9%) were aged 70 years and older. The most common etiology for aortic and mitral disease was degenerative (77.1%), rheumatic (10%), and endocarditis or prosthetic-related, or both, in the rest. Tricuspid valve disease was functional in 96%. New York Heart Association functional class III/IV was present in 69.4%, and 24% had had previous cardiac operations. One or more concomitant cardiac procedures were performed in 77 patients (58.8%), including coronary revascularization in 54. All aortic procedures were replacements, 14 patients required a prosthetic root conduit and 7 thoracic aorta replacement. Mitral replacements were used in 55%, repairs in 45%, and 96.2% of tricuspid procedures were repairs. Univariate and multivariate analyses were used to determine predictors of adverse outcomes. RESULTS: The 30-day and hospital mortality was 10.6% (n=14). Major complications occurred in 70 (53.4%). Univariate analysis identified New York Heart Association functional class III/IV (p=0.04), preoperative renal failure requiring dialysis (p=0.04), urgent operation (p=0.04), intraaortic balloon pump placement (p=0.02), and postoperative low cardiac output (p<0.0001) as predictors for early death. Proximal aortic operations, urgent operation, and New York Heart Association class IV correlated with increased early mortality (p<0.04) in patients aged 70 and older in addition to their decreased overall survival and decreased likelihood of discharge to home. Overall actuarial survival at 1, 5, and 10 years was 84.5%, 75%, and 45%, respectively. CONCLUSIONS: TVS remains a surgical challenge in the modern era. Despite a trend of increasing age and surgical risk, the early mortality rate and long-term survival remain respectable. Advanced age is associated with increased perioperative risk, but age per se should not be a contraindication for TVS.

Antegrade versus retrograde cerebral protection in repair of acute ascending aortic dissection.

The objective of this study was to compare retrograde with antegrade cerebral protection during acute aortic dissection repair using cerebral oximetry measurements. Fifty consecutive acute ascending aortic dissection repairs were analyzed. Cerebral oximetry data were collected for 41 of 50. Eight patients who had antegrade cerebral protection alone and 29 of 41 had retrograde cerebral protection alone. The per cent change in cerebral oximetry values during deep hypothermic circulatory arrest from baseline and from prearrest values was compared for the two groups using Student t test. The per cent change from baseline for the antegrade patients was: right 13.8 per cent and left -2.5 per cent; the per cent change from baseline for retrograde patients was: right 0.8 per cent and left 0.2 per cent (P values 0.216 and 0.725, respectively). The per cent change from the prearrest value for the antegrade patients was: right -12 per cent and left -15 per cent; the per cent change from prearrest for retrograde patients was: right -15 per cent and left -16 per cent (P values 0.514 and 0.956, respectively). No compelling evidence for an advantage to either antegrade or retrograde cerebral perfusion was detected. Further study with a focus on neurologic outcomes is warranted.

Thoracic aortic mobile thrombus: is there a role for early surgical intervention?

BACKGROUND: The diagnosis of thoracic aortic mobile thrombus (TAMT) is rare and is usually made after debilitating embolic events. The optimal treatment strategy is unknown. We report 14 patients with TAMT and aim to better define the role of early (less than 2 weeks) surgical thrombectomy. METHODS: Between February 1996 and February 2010, we treated 14 patients (9 women; aged 32 to 84 years, mean age 51 years) with TAMT. Hypercoagulable disorders or a strong family history of vascular thrombosis, or both, occurred in 9 patients. Diagnosis was made by transesophageal echocardiogram in 6, computed tomography angiography in 7, and digital subtraction angiography in 1. Embolic locations were extremities (n=9), cerebral (n=6), and abdominal (n=6). Aortic thrombi (n=17) locations were ascending/arch (n=7), descending (n=8), and thoracoabdominal (n=2). RESULTS: All patients were initially treated with heparin and aspirin. Thoracic aortic thrombectomies were performed in 8 patients within 2 weeks of diagnosis: left thoracotomy (n=5), thoracoabdominal (n=1), and median sternotomy (n=2). Left atrial-femoral bypass was used in 5 patients, cardiopulmonary bypass in 2, and no support in 1. Additional procedures were celiac artery (n=1) and left subclavian artery (n=2) thrombectomies. Procedures for embolic complications were performed in 7 patients before aortic thrombectomy. Operative mortality was 0%, with no recurrent embolic events after 24±16 months. One patient had thrombectomy of the ascending aorta and medical therapy with warfarin and aspirin for a second concurrent small thrombus in the descending aorta. One patient presented with multiorgan failure and died shortly after admission. Six patients treated medically were discharged on a regimen of oral warfarin and aspirin (14±11 months follow-up), with 2 fatal recurrent embolic events within 6 weeks (p=0.09). CONCLUSIONS: Thoracic aortic mobile thrombus is rare and is commonly associated with morbid thromboembolic events. In our experience, early surgical aortic thrombectomy had a low operative risk and may prevent fatal recurrent embolic events.

Proximal thoracic aortic replacement for aneurysmal disease using the freestyle stentless bioprosthesis: a 10-year experience.

BACKGROUND: Porcine bioprosthesis (bioroots) are an attractive surgical strategy for ascending aorta and arch replacement. This study evaluated the perioperative and late outcomes using this strategy for proximal aortic aneurysmal disease. METHODS: Between March 1998 and November 2009, 170 patients (40% women; median age, 70 years) underwent proximal thoracic aortic replacement using the Freestyle (Medtronics Inc, Minneapolis, MN) bioroot, with graft extension in 149 (87.6%). Aneurysmal etiology included degenerative-atherosclerotic (91.2%), acute dissection (5.3%), and chronic dissection (3.5%); 78% had greater than moderate aortic insufficiency. Surgical procedures were bioroot alone or with aortoplasty (12.3%), bioroot with ascending aortic graft (38.2%), bioroot with hemiarch graft (44.1%), and bioroot with total arch (5.3%). Hypothermic circulatory arrest was required in 49%. RESULTS: The 30-day mortality was 4.7% (n=8). The overall complication rate was 58% (n=100), including stroke (6.5%), renal failure (9.2%), respiratory failure (25.9%), and postoperative bleeding (7.6%). Mean hospitalization was 10.5±7.3 days; 38 were discharged to a rehabilitation facility (23.5%). Predictors of 30-day/hospital death were coronary artery disease (p=0.0003), renal insufficiency (p<0.0001), emergent/urgent procedure (p=0.02), and hypothermic circulatory arrest (p=0.002). The 1-year, 5-year, and 10-year survivals were 90%, 80%, and 35% respectively. Freedom from endocarditis and reoperation was 96% at 1 year and 94% and 95% at 5 years, respectively. CONCLUSIONS: Proximal thoracic aortic replacement using a porcine bioroot as part of the repair can be achieved with low perioperative mortality and acceptable late survival in a predominantly elderly population.

Hemiarch aortic replacement for acute type A dissection in a Marfan patient with twin pregnancy.

Type A aortic dissection is a high risk surgical emergency. Its occurrence during pregnancy represents an extremely high risk for death and sequelae for both the mother and the fetus. Surgical treatment in the form of cesarean delivery and aortic repair using hypothermia and circulatory arrest is mandatory in most patients. We report the case of a 29-year-old Marfan female with an acute type A aortic dissection at 34 weeks of a twin pregnancy. She underwent cesarean delivery of male twins followed by repair of the ascending aorta and proximal arch using deep hypothermia and circulatory arrest. The mother and twin babies survived without sequelae and are alive at two years.