Early Detection and Correction of Cerebral Desaturation With Noninvasive Oxy-Hemoglobin, Deoxy-Hemoglobin, and Total Hemoglobin in Cardiac Surgery: A Case Series.

Regional cerebral oxygen saturation (rS o2 ) obtained from near-infrared spectroscopy (NIRS) provides valuable information during cardiac surgery. The rS o2 is calculated from the proportion of oxygenated to total hemoglobin in the cerebral vasculature. Root O3 cerebral oximetry (Masimo) allows for individual identification of changes in total (ΔcHbi), oxygenated (Δ o2 Hbi), and deoxygenated (ΔHHbi) hemoglobin spectral absorptions. Variations in these parameters from baseline help identify the underlying mechanisms of cerebral desaturation. This case series represents the first preliminary description of Δ o2 Hbi, ΔHHbi, and ΔcHbi variations in 10 cardiac surgical settings. Hemoglobin spectral absorption changes can be classified according to 3 distinct variations of cerebral desaturation. Reduced cerebral oxygen content or increased cerebral metabolism without major blood flow changes is reflected by decreased Δ o2 Hbi, unchanged ΔcHbi, and increased ΔHHbi Reduced cerebral arterial blood flow is suggested by decreased Δ o2 Hbi and ΔcHbi, with variable ΔHHbi. Finally, acute cerebral congestion may be suspected with increased ΔHHbi and ΔcHbi with unchanged Δ o2 Hbi. Cerebral desaturation can also result from mixed mechanisms reflected by variable combination of those 3 patterns. Normal cerebral saturation can occur, where reduced cerebral oxygen content such as anemia is balanced by a reduction in cerebral oxygen consumption such as during hypothermia. A summative algorithm using rS o2 , Δ o2 Hbi, ΔHHbi, and ΔcHbi is proposed. Further explorations involving more patients should be performed to establish the potential role and limitations of monitoring hemoglobin spectral absorption signals.

Intra-abdominal pressure during and after cardiac surgery: a single-centre prospective cohort study.

PURPOSE: While intra-abdominal hypertension (IAH) has been associated with adverse outcomes in multiple settings, the epidemiology and clinical implications of IAH in the context of cardiac surgery are less known. In this study, we aimed to describe the prevalence of IAH in patients undergoing cardiac surgery and determine its association with patient characteristics and postoperative outcomes. METHODS: We conducted a single-centre prospective cohort study in which intra-abdominal pressure was measured in the operating room after general anesthesia (T1), after the surgical procedure (T2), and two hours after intensive care unit (ICU) admission (T3) in a subset of patients. Intra-abdominal hypertension was defined as intra-abdominal pressure (IAP) ≥ 12 mm Hg. Postoperative outcomes included death, acute kidney injury (AKI), and length of stay in the ICU and hospital. RESULTS: A total of 513 IAP measurements were obtained from 191 participants in the operating room and 131 participants in the ICU. Intra-abdominal hypertension was present in 105/191 (55%) at T1, 115/191 (60%) at T2, and 31/131 (24%) at T3. Intra-abdominal pressure was independently associated with body mass index, central venous pressure, and mean pulmonary artery pressure but was not associated with cumulative fluid balance. Intraoperative IAH was not associated with adverse outcomes including AKI. CONCLUSIONS: Intra-abdominal hypertension is very common during cardiac surgery but its clinical implications are uncertain.

RéSUMé: OBJECTIF: Bien que l'hypertension intra-abdominale (HIA) ait été associée à des issues indésirables dans de multiples contextes, l'épidémiologie et les implications cliniques de l'HIA dans le contexte de la chirurgie cardiaque sont moins connues. Dans cette étude, nous avons cherché à décrire la prévalence de l'HIA chez les patients bénéficiant d'une chirurgie cardiaque et à déterminer son association avec les caractéristiques des patients et les issues postopératoires. MéTHODE: Nous avons mené une étude de cohorte prospective monocentrique dans laquelle la pression intra-abdominale a été mesurée en salle d'opération après une anesthésie générale (T1), après l'intervention chirurgicale (T2) et deux heures après l'admission à l'unité de soins intensifs (USI) (T3) dans un sous-ensemble de patients. L'hypertension intra-abdominale a été définie comme une pression intra-abdominale (PIA) ≥ 12 mmHg. Les issues postopératoires comprenaient le décès, l'insuffisance rénale aiguë (IRA), et la durée du séjour à l'USI et à l'hôpital. RéSULTATS: Au total, 513 mesures de la PIA ont été obtenues auprès de 191 participants en salle d'opération et de 131 participants à l'USI. L'hypertension intra-abdominale était présente chez 105/191 patients (55 %) à T1, 115/191 (60 %) à T2 et 31/131 (24 %) à T3. La pression intra-abdominale était indépendamment associée à l'indice de masse corporelle, à la pression veineuse centrale et à la pression artérielle pulmonaire moyenne, mais n'était pas associée à un bilan hydrique cumulatif. L'HIA peropératoire n'était pas associée à des issues indésirables, y compris à l'IRA. CONCLUSION: L'hypertension intra-abdominale est très fréquente lors d'une chirurgie cardiaque, mais ses implications cliniques sont incertaines.

Endovascular Vena Cavae Occlusion Technique in Minimally Invasive Tricuspid Valve Surgery in Patients With Previous Cardiac Surgery.

OBJECTIVES: The aim of the present study was to describe a bicaval endovascular occlusion technique in minimally invasive tricuspid valve (TV) surgery in patients with previous cardiac surgery. DESIGN: Case series. SETTING: Single tertiary university center. PARTICIPANTS: The study comprised ten patients. INTERVENTIONS: Endovascular occlusion of vena cavae for minimally invasive TV redo surgery. MEASUREMENTS AND MAIN RESULTS: Between 2008 and 2017, ten patients with previous cardiac surgery underwent TV minimally invasive surgery (repair or replacement; isolated or with concomitant procedures) using the Coda balloon catheter (Cook Medical, Bloomington, IN) to occlude both vena cavae. Data were collected retrospectively from electronic medical records. Superior and inferior vena cava occlusion with Coda balloon catheters was successful with no complications. The drainage of the vena cavae was optimal with excellent surgical exposure. Cardiopulmonary bypass time was 131 ± 119 minutes, with 30% of patients undergoing aortic clamping (two with a Chitwood clamp, one with an endoaortic balloon). Intensive care unit length of stay was 3.9 ± 2.7 days, and the in-hospital mortality rate was 30%. CONCLUSION: Bicaval endovascular occlusion of vena cavae is a feasible and effective technique in patients with previous cardiac surgery who are undergoing a minimally invasive TV procedure. The high mortality rate is associated with the inherent risk of a redo surgery involving the TV.

Contemporary outcomes of aortic and mitral valve surgery for rheumatic heart disease in sub-Saharan Africa.

OBJECTIVES: Rheumatic heart disease is endemic in sub-Saharan Africa. There is a paucity of data on the outcomes of valvular surgery for rheumatic heart disease in the developing world. The objective of this study was to evaluate the outcomes of aortic and mitral valve surgery for rheumatic heart disease in Ethiopia. METHODS: Between 2009 and 2017, 240 consecutive patients with rheumatic heart disease underwent aortic and/or mitral surgery at the Cardiac Center of Ethiopia in Addis Ababa. These surgeries were performed in the context of 22 international humanitarian missions. Median follow-up was 2.3 (interquartile range, 0.5-4.0) years and 96% complete. Outcomes were compared between patients who underwent mechanical valve implantation (n = 90, 38%), bioprosthetic valve implantation (n = 58, 24%), and valve repair (n = 92, 38%). RESULTS: Mean age of patients was 19 ± 8 years, and 136 patients (57%) were female. Operative mortality occurred in 5 patients (2.1%) and was not significantly different between the groups. Eleven additional patients (5%) died at follow-up, and 55 patients (23%) had at least 1 major adverse valve-related event. Propensity score-adjusted Cox regression analysis demonstrated higher rates of death in the bioprosthetic group compared with the mechanical group (hazard ratio, 8.82; 95% confidence interval, 1.64-47.39; P = .011). Survival was not significantly different between the repair and mechanical groups (hazard ratio, 1.09; 95% confidence interval, 0.17-7.16; P = .93). Likewise, rates of major adverse valve-related event were higher in the bioprosthetic group compared with the mechanical group (hazard ratio, 2.71; 995% confidence interval, 1.13-6.49; P = .025), but not significantly different between the repair and mechanical groups (hazard ratio, 1.98; 95% confidence interval, 0.89-4.39; P = .092). CONCLUSIONS: Left-sided valve surgery for rheumatic heart disease in sub-Saharan Africa is associated with acceptable perioperative outcomes, but a high incidence of major adverse valve-related event at follow-up. The use of bioprosthetic valves is associated with poor outcomes in this patient population.

In Vivo Protamine Titration Using Activated Coagulation Time to Neutralize Heparin Anticoagulation in Cardiac Surgery: Proof of Concept.

OBJECTIVE: In vivo protamine titration (IVPT) is based on the observation of a plateau on the decay curve of the celite activated clotting times (ACTs) during protamine infusion for heparin reversal. The aim of the present study was to determine the optimal protamine/heparin ratio to reverse anticoagulation using IVPT curves. DESIGN: Prospective, randomized study. SETTING: Tertiary care university hospital. PARTICIPANTS: The study comprised 138 patients undergoing elective cardiac surgery requiring cardiopulmonary bypass. INTERVENTIONS: The control group was given a protamine infusion of 1.3 mg per 1 mg (100 U) of heparin over 21 minutes. ACT was measured every 3 minutes. In the test group, the protamine dose was prepared using the same ratio as for the control group, and ACT values were measured every 3 minutes until a plateau was reached (2 consecutive ACT values <160 s), at which time the protamine infusion was stopped. The protamine/heparin ratio, blood losses, transfusions, and heparin concentrations were recorded. RESULTS: The protamine dose was lower in the test group (456.00 ± 105.66 mg [control group] v 295.25 ± 100.60 mg [test group]; p < 0.0001). The mean protamine/heparin ratios were 1.30 ± 0.10 (control group) and 0.81 ± 0.22 (test group) (p < 0.0001). Heparin concentrations were greater in the test group 15 minutes (0.10 [0-0.2] U/mL v 0 [0-0.1] U/mL; p = < 0.0001) and 3 hours (0 [0-0.1] U/mL v 0 [0-0] U/mL; p = 0.0002) after protamine infusion. There was no difference in the blood losses and transfusion requirements. CONCLUSIONS: IVPT is safe and efficient in this low-risk population.

Acute Right Ventricular Failure in Cardiac Surgery During Cardiopulmonary Bypass Separation: A Retrospective Case Series of 12 Years' Experience With Intratracheal Milrinone Administration.

OBJECTIVE: To report the authors' 12 years of experience with intratracheal milrinone administration and to assess the efficacy and limitations of intratracheal milrinone bolus administration for the treatment of unexpected acute right ventricular (RV) failure in patients undergoing cardiac surgery. DESIGN: Retrospective analysis. SETTING: Single-center university hospital. PARTICIPANTS: One hundred seventy-six patients (4.6%) undergoing on-pump cardiac surgery. INTERVENTIONS: Endotracheal tube administration of milrinone (5-mg bolus) after unexpected acute RV failure during separation from cardiopulmonary bypass (CPB) weaning. RV failure was defined as the simultaneous presence of all of the following criteria: (1) hemodynamic instability or difficult separation from CPB with associated elevated central venous pressure or abnormal RV pressure waveform, (2) >20% reduction of RV fractional area change from baseline evaluated by transesophageal echocardiography, and (3) anatomical visualization of impaired or absent RV wall motion by direct intraoperative visual inspection. MEASUREMENTS AND MAIN RESULTS: Intratracheal milrinone administration was found to improve RV failure in 109 patients (61.9%) whereas RV failure persisted in 67 patients (38.1%). Using a multiple logistic regression model, severely decreased left ventricular ejection fraction (<35% v >50%) (adjusted odds ratio [OR] 3.72; 95% confidence interval [CI] 1.2-11.3; p = 0.012), longer CPB time (adjusted OR 1.014; CI 1.01-1.02; p = 0.001) and elevated postoperative fluid balance (adjusted OR 1.39; CI 1.1-1.8; p = 0.02) were found to be significant predictors of persistent RV failure. CONCLUSION: Intratracheal instillation of milrinone was associated with clinical improvement of RV failure occurring during separation from CPB in almost two-thirds of patients. Factors limiting its therapeutic efficacy include severe left ventricular dysfunction, increased fluid balance, and long CPB time.

Myocardial Protection in Minimally Invasive Mitral Valve Surgery: Retrograde Cardioplegia Alone Using Endovascular Coronary Sinus Catheter Compared With Combined Antegrade and Retrograde Cardioplegia.

OBJECTIVE: To compare myocardial protection with retrograde cardioplegia alone with antegrade and retrograde cardioplegia in minimally invasive mitral valve surgery (MIMS). DESIGN: Retrospective study. SETTING: Tertiary care university hospital. PARTICIPANTS: The authors studied 97 MIMS patients using retrograde cardioplegia alone and 118 MIMS patients using antegrade and retrograde cardioplegia. INTERVENTIONS: The data from patients admitted for MIMS using retrograde cardioplegia (MIMS retro) between 2009 to 2012 were compared with the data from patients undergoing MIMS with antegrade and retrograde cardioplegia (MIMS ante-retro) between 2006 and 2010 (control group). Cardioplegia in the MIMS retro group was delivered solely through an endovascular coronary sinus (CS) catheter positioned under echographic and fluoroscopic guidance. Antegrade and retrograde cardioplegia was used in the MIMS ante-retro group. Data regarding myocardial infarction (MI; creatine kinase Mb, troponin T, electrocardiogram), myocardial function, and hemodynamic stability were collected for comparison. MEASUREMENTS AND MAIN RESULTS: Adequate cardioplegia administration (CS pressure >30 mmHg and asystole) was attained in 74.2% of the patients with retrograde cardioplegia alone. In 23.7% of the patients, the addition of an antegrade cardioplegia was necessary. No difference was observed in the incidence of MI (0 MIMS retro v 1 for MIMS ante-retro, p = 0.3623), difficult separation from cardiopulmonary bypass, and postoperative malignant arrhythmia. No difference was found for maximal creatine kinase Mb (39.1 [28.0-49.1] v 37.9 [28.6-50.9]; p = 0.8299) and for maximal troponin T levels (0.39 [0.27-0.70] v 0.47 [0.32-0.79]; p = 0.1231) for MIMS retro and MIMS ante-retro, respectively. However, lactate levels in the MIMS retro group were significantly lower than in the MIMS ante-retro group (2.1 [1.4-3.05] v 2.4 [1.8-3.3], respectively; p = 0.0453). No difference was observed in duration of intensive care unit stay and death. MIMS retro patients had a shorter hospital stay (7.0 [6.0-8.0] v 8.0 [7.0-9.0] days; p = 0.0003). CONCLUSION: Retrograde cardioplegia administration alone provided comparable myocardial protection to antegrade and retrograde cardioplegia during MIMS, but was not sufficient to achieve asystole in one-fifth of patients.

Perioperative Right Ventricular Pressure Monitoring in Cardiac Surgery.

Right ventricular (RV) dysfunction is a cause of increased morbidity and mortality in both cardiac surgery and noncardiac surgery and in the intensive care unit. Early diagnosis of this condition still poses a challenge. The diagnosis of RV dysfunction traditionally is based on a combination of echocardiography, hemodynamic measurements, and clinical symptoms. This review describes the method of using RV pressure waveform analysis to diagnose and grade the severity of RV dysfunction. The authors describe the technique, optimal use, and pitfalls of this method, which has been used at the Montreal Heart Institute since 2002, and review the current literature on this method. The RV pressure waveform is obtained using a pulmonary artery catheter with the capability of measuring RV pressure by connecting a pressure transducer to the pacemaker port. The authors describe how RV pressure waveform analysis can facilitate the diagnosis of systolic and diastolic RV dysfunction, the evaluation of RV-arterial coupling, and help diagnose RV outflow tract obstruction. RV pressure waveform analysis also can be used to guide pharmacologic treatment and fluid resuscitation strategies for RV dysfunction.

Mini Right Anterior Thoracotomy Approach Versus Sternotomy for Resection of Intracardiac Myxoma.

OBJECTIVE: The standard approach in treating cardiac myxoma is the median full sternotomy. After recent advances in surgical techniques, the mini right anterior thoracotomy has emerged as an alternative method. METHODS: We performed a retrospective study to compare the clinical outcomes of the mini right anterior thoracotomy approach with those of the sternotomy approach for resection of cardiac myxoma at the Montreal Heart Institute. There were 20 patients treated using a mini right anterior thoracotomy (4-5 cm) and 23 patients were treated using a median sternotomy. RESULTS: No early mortalities were found in either group. Although the cardiopulmonary bypass time and aorta cross-clamp time were not significantly different between the two groups (64.3 mn ± 18 and 37.2 mn ± 15 vs 54.3 mn ± 25 and 37.20 mn ± 2), preoperative blood loss (106 mn ± 95 vs 338 mn ± 270) was significantly less in the mini right anterior thoracotomy group. The intensive care unit and hospital stay (1.65 days ± 1.2 and 5.70 days ± 3) were shorter with the mini right anterior thoracotomy approach. CONCLUSIONS: A minimally invasive surgery through mini right anterior thoracotomy is a good alternative technique for treating cardiac myxoma. Despite the small size of the experience, there is a clear diminution in preoperative blood loss and an interesting trend toward a shorter intensive care unit and hospital stay.

Subclavian and axillary vessel anatomy: a prospective observational ultrasound study.

PURPOSE: The primary objective of this study was to define the ultrasound-derived anatomy of the axillary/subclavian vessels. As a secondary objective, we evaluated the relationship between the vascular anatomy and demographic, anthropometric, and hemodynamic data of patients. METHODS: This observational anatomical study used bedside ultrasound with 150 cardiac surgical patients in the operating room. Bilateral axillary and subclavian anatomy was determined using a high-frequency ultrasound probe with fixed reference points. Images were recorded and analyzed, and correlation with demographic, anthropometric, and hemodynamic data was performed. RESULTS: The images were adequate to evaluate potential anatomical variations in 97.4% of patients with a body mass index as high as 46.4 kg·m-2. The mean (standard deviation) diameter of the axillary vein was 1.2 (0.3) cm on the right side and 1.1 (0.2) cm on the left side. The dimensions of the axillary vein were larger on the right side in 69% of patients. The vein was located directly over the artery in the mid-clavicular view in 67% of the patients and in lateral-clavicular view in only 7% of the patients. As we moved the probe laterally, the vein was lateralized in relation to the artery in 89% of patients. There was no significant correlation between the hemodynamic data and vessel size, although direct correlation was found between body mass index and the depth of the vessel (P < 0.001). The axillary vein area was smaller in females than in males (P < 0.002), and in 4% of patients, the axillary vein was in an aberrant position. CONCLUSIONS: In patients undergoing cardiac surgery, axillary vessel anatomy varied considerably, and the patients' hemodynamics could not predict the size of the axillary vessels. Only the patients' weight correlated moderately with the depth of the vein.

Myocardial Protection in Mitral Valve Surgery: Comparison Between Minimally Invasive Approach and Standard Sternotomy.

OBJECTIVE: To compare antegrade and retrograde cardioplegia administration in minimally invasive mitral valve surgery (MIMS) and open mitral valve surgery (OMS) for myocardial protection. DESIGN: Retrospective study. SETTING: Tertiary care university hospital. PARTICIPANTS: The study comprised 118 patients undergoing MIMS and 118 patients undergoing OMS. INTERVENTIONS: The data of patients admitted for MIMS from 2006 to 2010 were reviewed. Patients undergoing isolated elective OMS from 2004 to 2006 were used as a control group. Cardioplegia in the MIMS group was delivered via the distal port of the endoaortic clamp and an endovascular coronary sinus catheter positioned using echographic and fluoroscopic guidance. Antegrade and retrograde cardioplegia were used in OMS. Data regarding myocardial infarction (MI) (creatine kinase [CK]-MB, troponin T, electrocardiography); myocardial function; and hemodynamic stability were collected. MEASUREMENTS AND MAIN RESULTS: There was no difference in the perioperative MI incidence between both groups (1 in each group, p = 0.96). No statistically significant difference was found for maximal CK-MB (35.9 µg/L [25.1-50.1] v 37.9 µg/L [28.6-50.9]; p = 0.31) or the number of patients with CK-MB levels >50 µg/L (29 v 33; p = 0.55) or CK-MB >100 µg/L (3 v 4; p = 0.70) between the OMS and MIMS groups. However, maximum troponin T levels in the MIMS group were significantly lower (0.47 µg/L [0.32-0.79] v 0.65 µg/L [0.45-0.94]; p = 0.0007). No difference in the incidence of difficult weaning from bypass and intra-aortic balloon pump use between the MIMS and OMS groups was found. CONCLUSIONS: Antegrade and retrograde cardioplegia administration during MIMS and OMS provided comparable myocardial protection.

Low-Dose Versus High-Dose Tranexamic Acid Reduces the Risk of Nonischemic Seizures After Cardiac Surgery With Cardiopulmonary Bypass.

OBJECTIVE: The incidence of postoperative nonischemic seizures associated with the use of tranexamic acid (TXA) and the possibility of prevention with a low-dose regimen of TXA were evaluated. DESIGN: Retrospective study. SETTING: Tertiary care university hospital. PARTICIPANTS: A total of 12,195 patients who underwent cardiac surgical procedures under cardiopulmonary bypass (CPB) were evaluated. INTERVENTIONS: The files of every clinical seizure case diagnosed in the surgical intensive care unit between April 2006 and April 2014 were reviewed. Patients who experienced a postoperative seizure underwent a cerebral computed tomography scan to exclude an ischemic lesion. Dosage and type of antifibrinolytic used and surgery characteristics were retrieved from perfusion files. Low-dose TXA was defined as 1,000-mg bolus, 400-mg/h infusion, and 500 mg in CPB priming. High-dose TXA was defined as 30-mg/kg bolus, 15 mg/kg/h, and 2 mg/kg in CPB priming. RESULTS: No seizure was observed in the 886 patients who did not receive antifibrinolytics. A total of 98 clinical seizures (0.8%) were recorded in the intensive care unit, and ischemic cause was excluded in the majority of them after computed tomography scan results were reviewed (91 patients [93%]). Low-dose TXA was associated with fewer seizures than was high-dose TXA (46 of 7,452 cases [0.70%] v 34 of 2,190 cases [1.55%], respectively; p < 0.0001). Open-chamber cardiac surgery also was linked to a higher incidence of seizures compared with revascularization (80 of 6,662 [1.20%] and 11 of 5,533 [0.20%], respectively; p < 0.0001). CONCLUSIONS: Lower doses of TXA were associated with a lower incidence of nonischemic seizures compared with higher doses of the drug.

Assessment of fluid responsiveness with end-tidal carbon dioxide using a simplified passive leg raising maneuver: a prospective observational study.

BACKGROUND: Assessing fluid responsiveness is important in the management of patients with hemodynamic instability. Passive leg raising (PLR) is a validated dynamic method to induce a transient increase in cardiac preload and predict fluid responsiveness. Variations in end-tidal carbon dioxide (ETCO2) obtained by capnography correlate closely with variations in cardiac output when alveolar ventilation and carbon dioxide production are kept constant. In this prospective observational study, we tested the hypothesis that variations in ETCO2 induced by a simplified PLR maneuver can track changes in the cardiac index (CI) and thus predict fluid responsiveness. METHOD: A five-minute standardized PLR maneuver was performed in 90 paralyzed hemodynamically stable cardiac surgical patients receiving mechanical ventilation. Cardiac index was measured by thermodilution before and one minute after PLR. End-tidal CO2 measurements using capnography were obtained during the entire PLR maneuver. Fluid responsiveness was defined as a 15% increase in the CI. The Chi square test and Student's t test were used to compare responders and non-responders. Logistic regression analyses were then performed to determine factors of responsiveness. RESULTS: There were no differences between responders and non-responders in demographic and baseline hemodynamic variables. Fluid responsiveness was associated with an ETCO2 variation (ΔETCO2) of ≥ 2 mmHg during PLR [odds ratio (OR), 7.3; 95% confidence interval (CI), 2.7 to 20.2; P < 0.01; sensitivity 75%]. A low positive predictive value (54%) and a high negative predictive value (NPV) (86%) were observed. No other clinical or hemodynamic predictors were associated with fluid responsiveness. A logistic regression model established that a combination of ΔETCO2 ≥ 2 mmHg and a change in systolic blood pressure ≥ 10 mmHg induced by passive leg raising was predictive of fluid responsiveness (OR, 8.9; 95% CI, 2.5 to 32.2; P = 0.005). CONCLUSION: Use of a passive leg raising maneuver to induce variation in ETCO2 is a noninvasive and useful method to assess fluid responsiveness in paralyzed cardiac surgery patients receiving mechanical ventilation. Given its high NPV, fluid responsiveness is unlikely if a passive leg raising maneuver induces ΔETCO2 of < 2 mmHg.

Very high repair rate using minimally invasive surgery for the treatment of degenerative mitral insufficiency.

BACKGROUND: Minimally invasive mitral valve surgery (MIMVS) is an established alternative to median sternotomy for mitral valve repair. However, this technique has yet to gain widespread adoption, partly because of concerns that this approach might yield lower repair rates or repairs that are less durable than those performed through a sternotomy. The purpose of this study was to report our inaugural experience with MIMVS, with a focus on mitral valve repair rate and midterm outcomes. METHODS: Between May 2006 and April 2012, minimally invasive mitral valve repair was attempted in 200 consecutive patients with degenerative mitral disease. The approach used was a 4- to 5-cm right anterolateral minithoracotomy with femorofemoral cannulation for cardiopulmonary bypass. Mean follow-up was 2.9 ± 1.8 years, and follow-up was 99% complete. RESULTS: The mitral valve was successfully repaired in all but 2 patients, yielding a repair rate of 99%. Hospital mortality occurred in 2 patients (1%). Intraoperative conversion to sternotomy was necessary in 12 patients (6%), including 1 of the 2 unsuccessful repairs. Mean cardiopulmonary bypass and aortic cross-clamp times were 130.8 ± 41.3 minutes and 104.8 ± 35.6 minutes, respectively. Median hospital stay was 5 days. The 5-year survival and freedom from reoperation were 97.9% ± 1.5% and 98.1% ± 1.3%, respectively. CONCLUSIONS: A very high repair rate can be achieved using MIMVS for the treatment of degenerative mitral regurgitation, including during the learning phase. Midterm survival and freedom from valve-related reoperation are excellent. MIMVS is a safe and effective alternative to mitral valve repair through a sternotomy.

Preoperative vascular imaging for predicting intraoperative modification of peripheral arterial cannulation during minimally invasive mitral valve surgery.

OBJECTIVE: Minimally invasive mitral valve surgery using peripheral cannulation for cardiopulmonary bypass (CBP) is increasingly prevalent. Although conceptually straightforward, peripheral CBP involves challenges and risks specific to this method of perfusion. The utility of preoperative vascular imaging in predicting these technical challenges and preventing vascular complications was studied. METHODS: We performed a retrospective analysis of 73 consecutive patients undergoing minimally invasive mitral valve surgery using femorofemoral CBP with intraluminal aortic occlusion balloon catheter. All patients underwent preoperative computed tomography angiogram or magnetic resonance angiography to study the iliofemoral axes. RESULTS: None of the patients operated with this technique was found to have arterial stenoses. Patients with a femoral artery diameter of less than 7.3 mm needed bilateral or side-graft arterial cannulation significantly more frequently than patients with larger femoral arteries (46.2% vs 9.1%, P = 0.001). There was a trend toward more frequent modification of arterial cannulation strategy in patients with body surface area less than 1.7 m compared with larger patients (body surface area, 1.7-2.0) (26.3% vs 8.3%, P = 0.07). Patients needing high CBP flow rate (>5 L/min) were no more likely to need dual arterial cannulation (18.2% vs 19.1%, P = 0.68). No patient experienced a vascular complication. CONCLUSIONS: This preliminary study suggests that preoperative vascular imaging and patient evaluation may predict difficulties with femoral cannulation and perfusion, which can lead to better preoperative planning and potentially prevent vascular complications. Further data will be accumulated and analyzed to confirm these findings.

Innovative approaches in the perioperative care of the cardiac surgical patient in the operating room and intensive care unit.

Perioperative care for cardiac surgery is undergoing rapid evolution. Many of the changes involve the application of novel technologies to tackle common challenges in optimizing perioperative management. Herein, we illustrate recent advances in perioperative management by focusing on a number of novel components that we judge to be particularly important. These include: the introduction of brain and somatic oximetry; transesophageal echocardiographic hemodynamic monitoring and bedside focused ultrasound; ultrasound-guided vascular access; point-of-care coagulation surveillance; right ventricular pressure monitoring; novel inhaled treatment for right ventricular failure; new approaches for postoperative pain management; novel approaches in specialized care procedures to ensure quality control; and specific approaches to optimize the management for postoperative cardiac arrest. Herein, we discuss the reasons that each of these components are particularly important in improving perioperative care, describe how they can be addressed, and their impact in the care of patients who undergo cardiac surgery.

Minimally invasive mitral valve surgery: influence of aortic clamping technique on early outcomes.

BACKGROUND: Several methods of aortic clamping have been described for minimally invasive mitral valve surgery (MIMVS). The aim of this study was to compare the endoaortic balloon occlusion technique with the transthoracic clamp approach in terms of perioperative outcomes. METHODS: Between May 2006 and October 2011, a total of 259 patients underwent MIMVS through a 4 to 5 cm right anterolateral minithoracotomy. In 243 (93.8%) of these, the aorta was clamped using either the endoaortic balloon occlusion technique (endoballoon, n = 140) or the transthoracic clamp technique (transthoracic, n = 103). RESULTS: Patients in the endoballoon group had significantly longer operating time (4.3 ± 1.0 hours vs 3.2 ± 0.8 hours, p < 0.001), cardiopulmonary bypass time (143 ± 44 minutes vs 111 ± 29 minutes , p < 0.001), and cross-clamp time (114 ± 38 minutes vs 86 ± 23 minutes , p < 0.001). Perioperative blood loss was higher in the endoballoon group (287 ± 239 mL vs 213 ± 189 mL, p = 0.008) as was the mean postoperative creatinine kinase-MB level (36 ± 44 µg/L vs 26 ± 12 µg/L, p = 0.011). The repair rate was 99% or greater in both groups (p = 0.99). All patients left the operating room with no or trivial residual mitral regurgitation on transesophageal echocardiographic evaluation. In the endoballoon group there was 1 stroke (1%) and 5 myocardial infarctions (4%), compared with 2 strokes (2%) in the transthoracic group (p = not significant). There were 4 cases of postoperative cardiogenic shock, all of which occurred in the endoballoon group (p = 0.14). In-hospital mortality occurred in 2 patients from each group (p = 0.99). CONCLUSIONS: Minimally invasive mitral valve surgery can be performed successfully using either the endoaortic balloon technique or the transthoracic clamp approach. However, the transthoracic technique results in shorter operation time, less perioperative bleeding and better myocardial protection.

Reversal of decreases in cerebral saturation in high-risk cardiac surgery.

OBJECTIVES: To measure the incidence of cerebral desaturation during high-risk cardiac surgery and to evaluate strategies to reverse cerebral desaturation. DESIGN: Prospective observational study followed by a randomized controlled study with 1 intervention group and 1 control group. SETTING: Tertiary care center specialized in cardiac surgery. PARTICIPANTS: All patients were scheduled for high-risk cardiac surgery, 279 consecutive patients in the prospective study and 48 patients in the randomized study. INTERVENTIONS: An algorithmic approach of strategies to reverse cerebral desaturation. In the control group, no attempts were made to reverse cerebral desaturation. MEASUREMENTS AND MAIN RESULTS: Cerebral saturation was measured using near-infrared reflectance spectroscopy. A decrease of 20% from baseline for 15 seconds defined cerebral desaturation. The success or failure of the interventions was noted. Demographic data were collected. Models for predicting the probability and the reversal of cerebral desaturation were based on multiple logistic regressions. In the randomized study, 12 hours of measurements were continued in the intensive care unit without interventions. Differences in desaturation load (% desaturation × time) were compared between groups. Half of the high-risk patients had cerebral desaturation that could be reversed 88% of the time. Interventions resulted in smaller desaturation loads in the operating room and in the intensive care unit. CONCLUSIONS: Cerebral desaturation in high-risk cardiac surgery is frequent but can be reversed most of the time resulting in a smaller desaturation load. A large randomized study will be needed to measure the impact of reversing cerebral desaturation on patient's outcome.

The endovascular coronary sinus catheter in minimally invasive mitral and tricuspid valve surgery: a case series.

OBJECTIVES: To determine the safety and efficacy of a standardized approach to the use of an endovascular coronary sinus (CS) catheter during minimally invasive cardiac surgery. DESIGN: Case series. SETTING: University hospital. PARTICIPANTS: Patients undergoing mitral and/or tricuspid valve surgery using a minimally invasive cardiac surgery approach. INTERVENTIONS: An endovascular CS catheter was placed to enable the administration of retrograde cardioplegia using transesophageal echocardiography (TEE), fluoroscopy, and CS pressure measurements. MEASUREMENTS AND MAIN RESULTS: Data were collected from 96 patient records. A total of 95 (99.0%) endovascular coronary sinus catheters were positioned. The mean time to insert the catheter into the sinus ostium under TEE guidance was 6.3 ± 8.4 minutes. Confirmation of adequate positioning with fluoroscopy took an average of 9.1 ± 10.6 minutes for a mean total procedure time of 16.1 ± 14.1 minutes. Successful positioning, as defined by the ability to generate a perfusion pressure in the CS greater than 30 mmHg during surgery, was achieved in 87.5% of cases. During positioning, ventricularization of the CS pressure curve was observed in 86.0% of cases. The presence of ventricularization was associated with an increase in positioning success (odds ratio = 15.8; 95% confidence interval, 3.713-67.239). One patient developed extravasation of contrast agent after CS catheter placement, without evidence of CS rupture. CONCLUSIONS: Endovascular CS catheter insertion can be performed with a high rate of success for positioning and a low complication rate. During positioning, obtaining ventricularization is associated with an increased success rate.