Point-of-care testing for tranexamic acid efficacy: a proof-of-concept study in cardiac surgical patients.

BACKGROUND: Low-dose tranexamic acid (TXA) has been recently recommended for cardiopulmonary bypass (CPB) to reduce associated complications. Although point-of-care laboratory tests for TXA concentrations are unavailable, a novel TPA-test on the ClotPro® system can measure TXA-induced inhibition of fibrinolysis. We evaluated the performance of the TPA-test in vitro and in patients undergoing surgery requiring CPB. METHODS: Blood samples were obtained from six volunteers for in vitro evaluation of tissue plasminogen activator (tPA)-triggered fibrinolysis and the effects of TXA. This was followed by an observational study in 20 cardiac surgery patients to assess clinical effects of TXA on the TPA-test. RESULTS: Hyperfibrinolysis induced by tPA was inhibited by TXA ≥2 mg L-1 in a concentration-dependent manner, and was completely inhibited at TXA ≥10 mg L-1. In patients undergoing CPB, antifibrinolytic effect was detectable on TPA-test parameters after a 0.1 g bolus of TXA at the end of CPB, and complete inhibition of fibrinolysis was obtained with TXA ≥0.5 g. The antifibrinolytic effects of 1 g TXA on TPA-test parameters were gradually attenuated over 18 h after surgery. However, the fibrinolytic inhibition continued in four patients with estimated glomerular filtration rate (eGFR) ≤30 ml min-1 1.73 m-2. The eGFR had strong correlations with TPA-test parameters at 18 h after surgery (r=0.86-0.92; P<0.0001). CONCLUSIONS: The TPA-test is sensitive to low concentrations of TXA and serves as a practical monitoring tool for postoperative fibrinolytic activity in cardiac surgery patients. This test might be particularly useful in patients with severe renal impairment.

Utilizing a long sheath to minimize atheroma manipulation (minimal manipulation approach) during Zone 1 and 2 thoracic endovascular aortic repair with a shaggy aorta.

We have adopted a simple and reproducible approach, "minimal manipulation approach," since January 2021 in five patients to minimize the risk of thromboembolic events during Zone 1 and 2 thoracic endovascular aortic repair (TEVARs) with shaggy aorta. The approach consists of two parts: ① Use of a 65-cm-long sheath (dry seal) to deliver the endografts without touching the protruding atheroma. Covering the atheroma with the first endograft delivered at Zone 3 to the mid-descending aorta (paving the aorta), and second endograft insertion and deployment through the paved aorta with first endograft. ② Protection of the left subclavian artery using balloon catheter during TEVAR. No in-hospital mortality was recorded, and none of the patients had stroke, spinal cord ischemia, or distal embolic events.

Mid-Term Outcomes of "Complete Aortic Repair": Surgical or Endovascular Total Arch Replacement With Thoracoabdominal Fenestrated-Branched Endovascular Aortic Repair.

OBJECTIVE: To describe a single-center experience of "complete aortic repair" consisting of surgical or endovascular total arch replacement/repair (TAR) followed by thoracoabdominal fenestrated-branched endovascular aortic repair (FB-EVAR). METHODS: We reviewed 480 consecutive patients who underwent FB-EVAR with physician-modified endografts (PMEGs) or manufactured stent-grafts between 2013 and 2022. From those, we selected only patients treated with open or endovascular arch repair and distal FB-EVAR for aneurysms involving the ascending, arch and thoracoabdominal aortic segments (zones 0-9). Manufactured devices were used under an investigational device exemption protocol. Endpoints included early/in-hospital mortality, mid-term survival, freedom from secondary intervention, and target artery instability. RESULTS: There were 22 patients, 14 men and 8 women with a median age of 72±7 years. Thirteen postdissection and 9 degenerative aortic aneurysms were repaired with a mean maximum diameter of 67±11 mm. Time from index aortic procedure to aneurysm exclusion was 169 and 270 days in those undergoing 2- and 3-stage repair strategies, respectively. The ascending aorta and aortic arch were treated with 19 surgical and 3 endovascular TAR procedures. Three (16%) surgical arch procedures were performed elsewhere, and perioperative details were unavailable. Mean bypass, cross-clamp, and circulatory arrest times were 295±57, 216±63, and 46±11 minutes, respectively. There were 4 major adverse events (MAEs) in 2 patients: both required postoperative hemodialysis, 1 had postbypass cardiogenic shock necessitating extracorporeal membrane oxygenation, and the other required evacuation of an acute-on-chronic subdural hematoma. Thoracoabdominal aortic aneurysm repair was performed with 17 manufactured endografts and 5 PMEGs. There was no early mortality. Six (27%) patients experienced MAEs. There were 4 (18%) cases of spinal cord injury with 3 (75%) experiencing complete symptom resolution before discharge. Mean follow-up was 30±17 months in which there were 5 patient deaths-0 aortic related. Eight patients required ≥1 secondary intervention, and 6 target arteries demonstrated instability (3 IC, 1 IIIC endoleaks; 2 TA stenoses). Kaplan-Meier 3-year estimates of patient survival, freedom from secondary intervention, and target artery instability were 78±8%, 56±11%, and 68±11%, respectively. CONCLUSION: Complete aortic repair with staged surgical or endovascular TAR and distal FB-EVAR is safe and effective with satisfactory morbidity, mid-term survival, and target artery outcomes. CLINICAL IMPACT: The presented study demonstrates that repair of the entirety of the aorta - via total endovascular or hybrid means- is safe and effective with low rates of spinal cord ischemia. Cardiovascular specialists within comprehensive aortic teams at should feel confident that staged repair of the most complex degenerative and post-dissection thoracoabdominal aortic aneurysms can be safely performed in their patients with complication profile similar to that of less extensive repairs. Meticulous and intentional case planning is imperative for immediate and long-term success.

Side-by-side deployment of gore excluder legs at a narrow terminal aorta for endovascular aneurysm repair.

PURPOSE: A narrow terminal aorta is a risk factor for endograft occlusion after endovascular aneurysm repair. To minimize limb complications, we used Gore Excluder legs positioned side-by-side at the terminal aorta. We investigated the outcomes of our strategy for endovascular aneurysm repair in patients with a narrow terminal aorta. METHODS: We enrolled 61 patients who underwent endovascular aneurysm repair with a narrow terminal aorta (defined as < 18 mm in diameter) from April 2013 to October 2021. The standard procedure involves complete treatment with the Gore Excluder device. When other types of main body endografts were used, they were deployed proximal to the terminal aorta, and we used the Gore Excluder leg device in the bilateral limbs. Postoperatively, the intraluminal diameter of the legs at the terminal aorta was measured to assess the configuration. RESULTS: During the follow-up period (mean: 2.7 ± 2.0 years), there were no aorta-related deaths, endograft occlusions, or leg-related re-interventions. There were no significant differences between the pre- and postoperative ankle-brachial pressure index values in the dominant and non-dominant legs (p = 0.44 and p = 0.17, respectively). Postoperatively, the mean difference rate (defined as [dominant leg diameter-non-dominant leg diameter]/terminal aorta diameter) was 7.5 ± 7.1%. The difference rate was not significantly correlated with the terminal aortic diameter, calcification thickness, or circumferential calcification (r = 0.16, p = 0.22; r = 0.07, p = 0.59; and r = - 0.07, p = 0.61, respectively). CONCLUSIONS: Side-by-side deployment of Gore Excluder legs produces acceptable outcomes for endovascular aneurysm repair with a narrow terminal aorta. The endograft expansion at the terminal aorta is tolerable without influencing calcification distribution.

Whole Body Retrograde Perfusion Combined With Central Aortic Perfusion Strategy in the Repair of Distal Arch Pathology Through a Lateral Thoracotomy.

OBJECTIVE: To compare the results of the hypothermic circulatory arrest (HCA) + retrograde whole-body perfusion (RBP) technique with those of deep hypothermic circulatory arrest (DHCA-only) approach. METHODS: Limited data are available on cerebral protection techniques when distal arch repairs are performed through a lateral thoracotomy. In 2012, the RBP technique was introduced as adjunct to HCA during open distal arch repair via thoracotomy. We reviewed the results of the HCA + RBP technique compared with those of the DHCA-only approach. From February 2000 to November 2019, 189 patients (median age, 59 [IQR, 46 to 71] years; 30.7% female) underwent open distal arch repair via lateral thoracotomy to treat aortic aneurysms. The DHCA technique was used in 117 patients (62%, median age 53 [IQR, 41 to 60] years), whereas HCA + RBP was used in 72 patients (38%, median age 65 [IQR, 51 to 74] years). In HCA + RBP patients, cardiopulmonary bypass was interrupted when systemic cooling achieved isoelectric electroencephalogram; once the distal arch had been opened, RBP was then initiated via the venous cannula (flow of 700 to 1000 mL/min, central venous pressure <15 to 20 mm Hg). RESULTS: The stroke rate was significantly lower in the HCA + RBP group (3%, n=2) compared with the DHCA-only (12%, n=14) (P=.031), despite longer circulatory arrest times in HCA + RBP compared with the DHCA-only (31 [IQR, 25 to 40] minutes vs 22 [IQR, 17 to 30] minutes, respectively; P<.001). Operative mortality for patients undergoing HCA + RBP was 6.7% (n=4), whereas for those undergoing DHCA-only it was 10.4% (n=12) (P=.410). The 1-, 3-, and 5-year age-adjusted survival rates for the DHCA group are 86%, 81%, and 75%, respectively. The 1-, 3-, and 5-year age-adjusted survival rates for the HCA + RBP group are 88%, 88%, and 76%, respectively. CONCLUSION: The addition of RBP to HCA in the treatment of distal open arch repair via a lateral thoracotomy is safe and provides excellent neurological protection.

Resisting arrest: Perioperative confirmation and management of an iatrogenic aortocoronary arteriovenous fistula after coronary artery bypass grafting for redo cardiac surgery.

Although rare, iatrogenic aortocoronary arteriovenous fistulae (ACAVF) occur when a coronary graft is mistakenly anastomosed to an epicardial vein rather than its intended arterial target. Patients may be asymptomatic, demonstrate angina, dyspnea, arrhythmias, syncope, or diminished exercise capacity, and may have wide pulse pressures with evidence of coronary steal. A thorough insight into the disordered anatomy is critical to safely manage a patient for redo cardiac surgery, especially when attempting to arrest the heart. We present a case for redo cardiac surgery of an iatrogenic ACAVF confirmed perioperatively with multiple modalities and its intraoperative management.

Effect of Left Ventricular Hyperenhancement in Magnetic Resonance Imaging on Reverse Remodeling After Mitral Valve Repair for Moderate Ischemic Mitral Regurgitation.

We aimed to investigate cardiac magnetic resonance imaging (MRI)-derived predictors of a lack of left ventricular (LV) reverse remodeling after undersized mitral annuloplasty (uMAP) for moderate ischemic mitral regurgitation (IMR). We retrospectively reviewed 31 patients who underwent uMAP for moderate IMR and cardiac MRI evaluation between 2004 and 2017. Cardiac MRI evaluation included cine MRI LV and right ventricular volumetric measurements and gadolinium-enhanced MRI assessment of myocardial scarring. LV dimensions were assessed preoperatively, postoperatively, and at follow-up using serial transthoracic echocardiography, and the mid-term (median, 49 months) predictors of a lack of LV reverse remodeling were analyzed. At the mid-term follow-up (mean follow-up period: 85 ± 40 months), 15 patients exhibited reverse LV remodeling. The relative reduction in LV dimension at follow-up was negatively correlated with the preoperative number of LV segments with myocardial infarction (MI) (defined as an LV segment with >25% enhancement). The optimal cut-off for predicting a lack of reverse LV remodeling at follow-up was >5 LV segments with MI, with a sensitivity and specificity of 92% and 92%, respectively. This cut-off value also predicted all-cause mortality at follow-up, with a sensitivity and specificity of 88% and 67%, respectively. The presence of >5 LV segments with MI on gadolinium-enhanced MRI might be a useful predictor of lack of reverse LV remodeling and all-cause mortality outcomes after undersized mitral annuloplasty for moderate IMR.

A comparison of the ClotPro system with rotational thromboelastometry in cardiac surgery: a prospective observational study.

Viscoelastic coagulation tests have been increasingly used for hemostasis management in cardiac surgery. The ClotPro system is a novel viscoelastic device based on principles of rotational thromboelastometry. We aimed to compare ClotPro with ROTEM and plasma coagulation assays in cardiopulmonary bypass (CPB) patients. Blood samples were collected from 25 CPB patients at (1) baseline, (2) start of CPB, (3) end of CPB, and (4) end of surgery. The EX-test, IN-test, HI-test, FIB-test parameters on ClotPro were compared with corresponding ROTEM assay (EXTEM, INTEM, HEPTEM, and FIBTEM). Standard plasma coagulation assays and endogenous thrombin generation (TG) were simultaneously evaluated. Pearson correlation analyses showed moderate correlations between clotting times (CTs) (r = 0.63-0.67; p < 0.001, respectively), and strong correlations with maximal clot firmness (MCF) (r = 0.93-0.98; p < 0.001, respectively) between ClotPro and ROTEM. EX-test and IN-test MCF parameters were interchangeable with acceptable percentage errors (EX-test MCF: 7.3%, IN-test MCF: 8.3%), but FIB-test MCF (27.0%) and CT results were not (EX-test CT: 44.7%, IN-test CT: 31.4%). The correlations of PT/INR or peak TG with EX-test CTs were higher than with EXTEM CTs (PT/INR: r = 0.80 and 0.41, peak TG: 0.43 and 0.18, respectively). FIB-test MCF has strong correlation with plasma fibrinogen and factor XIII level (r = 0.84 and 0.66, respectively). ROC analyses showed that ClotPro was capable of emulating well-established ROTEM thresholds (area under curves: 0.83-1.00). ClotPro demonstrated strong correlations in MCF parameters of ROTEM in CPB patients. It may be reasonable to modify ROTEM-based transfusion algorithm pertaining to MCF parameters to establish cut-off values for ClotPro device.

Clinical outcomes of mitral valve repair for degenerative mitral regurgitation in elderly patients.

OBJECTIVES: This study analyzes the safety and outcomes of mitral valve repair for degenerative mitral valve regurgitation in patients 75 years of age or older. METHODS: We retrospectively reviewed the clinical results of 343 patients aged ≥75 years who underwent mitral valve repair for degenerative mitral valve regurgitation as a primary indication between January 1998 and June 2017. RESULTS: The median (interquartile range) age of the patients was 79.4 (76.9, 82.9) years, and 132 (38.5%) patients were women. Concomitant procedures were performed in 123 patients: tricuspid surgery in 68 (19.8%) and a maze procedure or pulmonary vein isolation in 55 (16.0%). Operative mortality was 1.2%. Operative complications included atrial fibrillation in 37.9%, prolonged ventilation in 7.0%, pacemaker implantation in 3.8, renal failure requiring dialysis in 1.5 and stroke in 3 (0.9%). The median follow-up was 7.4 years (interquartile range, 3.5-14.1 years). The cumulative incidence rates of mitral valve reoperation were 2.2%, 3.2% and 3.2% at 1, 5 and 10 years, respectively. Overall survival at 1, 5 and 10 years were 95%, 83% and 51%, respectively. Older age, smoking and over and underweight were associated with increased risk of mortality, while higher left ventricular ejection fraction and hypertension were associated with reduced risk. CONCLUSIONS: Mitral valve repair in elderly patients can be accomplished with low operative mortality and complications. Mitral valve repair in the elderly remains the preferred treatment for degenerative mitral regurgitation.

Sufficient cardiac unloading by Impella 5.0 in left ventricular rupture following mitral valve replacement: a case report.

A 72-year-old woman presented with exertional dyspnea. Echocardiography revealed severe mitral valve stenosis; therefore, mitral valve replacement was performed using a bioprosthetic valve. However, left ventricular wall rupture occurred following mitral valve replacement. Under re-cardiac arrest, we found a left ventricular tear under the posterior annulus of the mitral valve. We repaired the left ventricular muscle using a bovine pericardial patch and implanted a bioprosthetic valve again. Postoperatively, we implanted an Impella 5.0 heart pump through the right axillary artery to ensure left ventricular wall unloading. Systemic blood flow depended almost completely on mechanical circulatory assistance until postoperative day 3. After the fourth postoperative day, we started weaning the patient from Impella 5.0. Finally, it was completely discontinued on the sixth postoperative day. After that, the patient's condition was stable, and she was discharged 44 days postoperatively. Impella 5.0 is a potentially beneficial device for left ventricular unloading in patients with left ventricular wall rupture following mitral valve replacement.

Serial changes in cardiac sympathetic nervous function after transcatheter aortic valve replacement: A prospective observational study using 123I-meta-iodobenzylguanidine imaging.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) can rapidly improve cardiac sympathetic nervous function (CSNF) within 2 weeks in patients with aortic stenosis (AS). However, whether such short-term improvements will be sustained thereafter remains unclear. METHODS: Patients with severe AS who underwent TAVR between October 2017 and June 2019 were enrolled in this single-center, prospective, observational study. 123I-meta-iodobenzylguanidine imaging was performed at baseline, within 2 weeks after TAVR, and at 6 to 12 months post-TAVR to evaluate the heart-mediastinum ratio (H/M) and washout rate. RESULTS: Of 183 consecutive patients, 75 (19 men; median age: 86 years) were evaluated. The late H/M significantly improved within 2 weeks after TAVR (P = .041) and further improved over 6 to 12 months after TAVR (P = .041). Multivariate analysis revealed that the baseline mean aortic valve pressure gradient (mPG) was an independent predictor of mid-term improvement in the late H/M (> 0.1) (P = .037). Patients with a high baseline mPG (≥ 58 mmHg) exhibited a significantly greater increase in the late H/M than those with a low baseline mPG (< 42 mmHg) (0.24 vs 0.01; P = .029). CONCLUSION: CSNF demonstrated sustained improvement from within 2 weeks after TAVR until 6 to 12 months later. Such improvement was related to baseline hemodynamic AS severity.

Staged total arch replacement, followed by fenestrated-branched endovascular aortic repair, for patients with mega aortic syndrome.

OBJECTIVE: The aim of the present study was to review the clinical outcomes of a staged approach using total arch replacement (TAR) with an elephant trunk or a frozen elephant trunk, followed by fenestrated-branched endovascular aortic repair (F-BEVAR) for patients with mega aortic syndrome. METHODS: We reviewed the clinical data and outcomes of 11 consecutive patients (8 men; mean age, 71 ± 7 years) treated by staged TAR and F-BEVAR from January 2014 to December 2018. The F-BEVAR procedures were performed under a prospective, nonrandomized, physician-sponsored investigational device exemption protocol. All patients had had mega aortic syndrome, defined by an ascending aorta, arch, and extent I-II thoracoabdominal aortic aneurysm. The endpoints were 30-day mortality, major adverse events (MAE), patient survival, freedom from reintervention, and freedom from target vessel instability. RESULTS: Of the 11 patients, 6 had developed chronic postdissection aneurysms after previous Stanford A (three A11, two A10, one A9) dissection repair and 5 had had degenerative aneurysms with no suitable landing zone in the aortic arch. The thoracoabdominal aortic aneurysms were classified as extent I in four patients and extent II in seven. One patient had died within 30 days after TAR (9.0%). However, none of the remaining 10 patients who had undergone F-BEVAR had died. First-stage TAR resulted in MAE in three patients (27%), including one spinal cord injury. The mean length of stay was 12 ± 6 days. The mean interval between TAR and F-BEVAR was 245 ± 138 days with no aneurysm rupture during the interval. Second-stage F-BEVAR was associated with MAE in two patients (20%), including spinal cord injury in one patient from spinal hematoma due to placement of a cerebrospinal fluid drain. The mean follow-up period was 14 ± 10 months. At 2 years postoperatively, patient survival, primary patency, secondary patency, and freedom from renal-mesenteric target vessel instability was 80% ± 9%, 94% ± 6%, 100%, and 86% ± 8%, respectively. No aortic-related deaths occurred during the follow-up period. Four patients had required reintervention, all performed using an endovascular approach. CONCLUSIONS: A staged approach to treatment of mega aortic syndrome using TAR and F-BEVAR is a feasible alternative for selected high-risk patients. Larger clinical experience and longer follow-up are needed.

Two-Stage Redo Aortic Arch Repair in a Patient With an Isolated Left Vertebral Artery.

A 47-year-old male presented with an enlarging distal aortic arch false lumen 6 months status post ascending and hemiarch replacement with antegrade endograft insertion for acute type A aortic dissection complicated by lower body malperfusion. Preoperative computed tomographic angiography showed an isolated but dominant left vertebral artery. A 2-stage open surgical repair was performed. First, the left subclavian artery was transposed on the common carotid and vertebral onto the subclavian. At the second stage, a redo total arch reconstruction was done with bypass grafts taken to the innominate and left common carotid arteries. The patient did well postoperatively.

Techniques and outcomes of total aortic arch repair with frozen elephant trunk for DeBakey I dissections.

Total aortic arch replacement (TAR) with frozen elephant trunk (FET) technique (FET) has been increasingly used to treat a variety of aortic pathologies over the past two decades. Because FET can effectively treat the diseased arch and cover the proximal entry tear in the distal arch, it is a valuable option in the treatment of DeBakey I aortic dissections. This report focuses on the techniques and outcomes of TAR with FET for acute/chronic aortic dissection. A review of pooled literature including 27 observational studies showed in-hospital mortality, permanent stroke, and spinal cord injury rates of 8.4%, 5.9% and 2.6% for acute aortic dissections, and 7.5%, 4.0% and 4.6% for chronic aortic dissections, respectively. In most of the studies, complete false lumen thrombosis rate was achieved in 80% of patients at the level of FET for acute and chronic aortic dissections. Mid-term outcomes are equally promising. For chronic aortic dissections, positive remodeling of the non-stented distal aortic segments is less frequent leading to secondary reinterventions within 3 to 5 years. However, most studies have not applied distal abdominal extensions of the repair using fenestrated and branched endografts. In the current endovascular era, TAR + FET should be considered as an alternative to conventional open surgical repair in centers of excellence.

Chronic Type A Aortic Dissection After Transcatheter Aortic Valve Replacement.

An 87-year-old man with a hostile ascending aorta who underwent transfemoral transcatheter aortic valve replacement (TAVR) using a 26-mm Sapien 3 valve (Edwards Lifesciences, Irvine, CA) 2 years earlier presented with chronic type A aortic dissection, which was retrospectively caused by the edge of the pusher of the TAVR implantation system. Redo sternotomy and extraction of the Sapien valve, followed by replacement of the ascending aorta and the aortic valve, were performed successfully. Retrospective image analysis showed the importance of respecting the anatomy of the ascending aorta before considering transfemoral TAVR.

Bilateral internal thoracic artery grafting: in situ or composite?

Bilateral internal thoracic artery (BITA) grafting is considered a superior choice for coronary artery bypass grafting (CABG). While the 10-year outcomes of BITA grafting from the recent Arterial Revascularization Trial (ART) are still pending, numerous observational studies have demonstrated the advantages of BITA grafting. These include better long-term graft patency and freedom from arteriosclerosis, in addition to higher survival rate compared to CABG using only the left internal thoracic artery (ITA). The different BITA configurations are in situ and composite-the choice of optimal grafting configuration is challenging. Patient factors such as coronary anatomy, presence of a diseased ascending aorta and the potential need for a future redo sternotomy will influence the choice of the grafting strategy. In situ BITA grafting is associated with excellent clinical outcomes and has been extensively described in the literature. However, uncertainties remain regarding the ideal in situ configuration and design. Composite BITA grafting is the other option that maximizes right ITA (RITA) utilization. In this configuration, the RITA is able to reach the distal circumflex and right coronary artery branches. This approach decreases the need for a third graft conduit.