Continuous Glucose Monitoring System After Coronary Artery Bypass Graft Surgery: A Feasibility Study.

BACKGROUND: Blood glucose level variability has been associated with increased risk of complication in the postoperative setting of cardiovascular surgery. Although interesting for optimization of blood glucose management in this context, continuous blood glucose (CBG) devices can have a limited reliability in this context, in particular because of the use of paracetamol. The aim of this study was to evaluate the reliability of Dexcom G6®, a recently developed continuous glucose monitoring device. METHODS: We performed a prospective, observational, non-randomized, single-centre study comparing Dexcom G6® CBG level monitoring with the standard methods routinely used in this context. The standard blood glucose values were paired to the time corresponding values measured with Dexcom G6®. Agreement between the two methods and potential correlation in case of paracetamol use were calculated. RESULTS: From May 2020 to August 2021, 36 out of 206 patients operated for isolated coronary artery bypass grafting were enrolled; 673 paired blood glucose level were analyzed. Global agreement (ρc) was 0.85 (95% C.I.: 0.84-0.86), intensive care unit agreement was 0.78 (95%C.I.: 0.74-0.82) and ward agreement was 0.91 (95%C.I.: 0.89-0.93). In the diabetic population, it was 0.87 (95%C.I.: 0.85-0.90). When paracetamol was used, the difference was 0.02 mmol/l (95%C.I.: 0.29-0.33). CONCLUSIONS: Dexcom G6® provides good blood glucose level accuracy in the postoperative context of cardiac surgery compared to the standard methods of measurements. The results are particularly reliable in the ward where the need for repeated capillary glucose measurements implies patient discomfort and time-consuming manipulations for the nursing staff.

Optimizing CO2 field flooding during sternotomy: In vitro confirmation of the Karolinska studies.

Although CO2 field-flooding was first used during cardiac surgery more than 60 years ago, its efficacy is still disputed. The invisible nature of the gas and the difficulty in determining the "safe" quantity to protect the patient are two of the main obstacles to overcome for its validation. Moreover, CO2 concentration in the chest cavity is highly sensitive to procedural aspects, such suction and hand movements. Based on our review of the existing literature, we identified four major factors that influence the intra-cavity CO2 concentration during open-heart surgery: type of delivery device (diffuser), delivery CO2 flow rate, diffuser position around the wound cavity, and its orientation inside the cavity. In this initial study, only steady state conditions were considered to establish a basic understanding on the effect of the four above-mentioned factors. Transient factors, such as suction or hand movements, will be reported separately.

Cardiac surgery simulation - part 2: Step-by-step Konno operation in a preclinical model.

This operation is performed on a preclinical model (porcine heart) that has been positioned and fixed inside a plastic mannequin, simulating the human anatomy. This set-up allows surgical operations to be performed at almost the same depth and orientation as in the operating theatre. The preclinical model allows the exact simulation of most of the key movements and steps of major adult and congenital operations. In this case, we replicate the Konno operation. This intervention addresses localized subaortic stenosis involving the left outflow tract or the narrowing of the left ventriculo-aortic junction.

del Nido versus hematic cardioplegia in minimally invasive aortic valve surgery.

BACKGROUND: The quality of a myocardial protection of a single-dose del Nido cardioplegia versus multiple dose blood-based cardioplegia on myocardial injury, outcomes and operative times in patients undergoing minimally invasive aortic valve replacement is basically unreported. METHODS AND RESULTS: Preoperative and post-operative data, as well as technical details from isolated minimally invasive aortic valve replacements, performed using single-dose or multiple-dose cardioplegia were prospectively collected and retrospectively analysed. A total of 110 patients undergoing minimally invasive valve replacements at our institution composed two groups: 55 patients in the blood cardioplegia group (BloCa) and 55 in the del Nido group (DeNiCa). The two-matched groups were comparable in terms of preoperative variables. In the DeNiCa group, there was a statistically significant less need for cardiac defibrillation after aortic cross-clamp release (p < 0.001). Moreover, the BloCa group received intraoperatively more blood transfusions (p = 0.001) and more insulin administration for higher glucose levels (p < 0.001). The BloCa group showed higher intraoperative lactate levels (p = 0.01). Need for post-operative inotropic and vasoactive support, Creatine Kinase-MB levels after 6 and 12 h, onset of post-operative atrial fibrillation and length of stay were similar. No deaths occurred in neither groups. CONCLUSION: Single-dose del Nido cardioplegia in the setting of minimally invasive aortic surgery seems to offer adequate myocardial protection, comparable to multiple dose hematic cardioplegia. It has been documented a lower peri-operative need of defibrillation after cross-clamp release, lactate- and glucose peak values, as well as less blood transfusions compared to blood cardioplegic strategy.

Digital interprofessional communication with families in a cardiac surgery unit: insights from the pandemic.

Background: The COVID-19 pandemic entailed cutting off the usual access to hospitals, denying patients daily visits from their relatives and friends. The standard communication between medical staff and relatives also suffered, with a perceived negative impact on overall care. We developed an electronic communication solution to re-establish a proactive daily communication with patients' families. Methods: The communication software allowed families to receive daily interprofessional (medical, nursing, and physiotherapy) updates by text message, on patients' postoperative clinical state. Appreciation and performance of this communication was evaluated through a prospective randomised study. Two groups were compared (group D, 32 patients "Digital" receiving daily SMS, and group S, 16 patients "Standard" without SMS), assessing satisfaction through dedicated surveys under COVID-19 restrictions. Moreover, private outgoing vs. incoming communication flow between patients and their relatives (phone calls and text messages, for both groups) were analysed at different timeframes of the postoperative hospital stay. Results: Mean age of the population was 66 ± 7 years for both groups. The digital communication service was successfully adopted in group D in all cases, sending overall 155 communications (4.84 per patient). Calls received from relatives were 13 in group D vs. 22 in group S (0.4 vs. 1.4 calls per patient, p = 0.002). Patients' outgoing vs. incoming traffic flow was equal in the two groups for every timeframe (first two postoperative days vs. the rest), independently from digital communication. Comparing satisfaction of communication (from 1 to 7), level of information and understandability resulted in 6.7 in group D vs. 5.6 in group S (p = 0.004). Appreciation of digital communication was highest during the first three postoperative days. Conclusion: The restrictions caused by the COVID-19 pandemic generated simple and effective ideas on digital solutions for interprofessional communication. Offering this digital service, which complements rather than replace the classic communication, eased the need of the families to be informed and significantly enhanced the overall satisfaction regarding the healthcare service. Summary: The COVID-19 pandemic has interrupted access to hospital patients and cut off physical contact, denying patients, their families, and medical staff the necessary constant communication about the progress of their stay. It has become necessary, therefore, to compensate for the lack of "physical" face-to-face interaction by introducing innovative digital communication solutions. Our interprofessional project aims to assess the overall satisfaction and acceptance of digital communication service between the hospital and the families, updating on postoperative clinical condition of patients. Specifically, the introduction of a digital communication module attached to the electronic patient record allows relatives to be informed on a daily basis. The development of this module/software enabled families to receive daily, interprofessional and proactive digital updates, on their relative ones' postoperative stay.

Cardiac surgery simulation: step-by-step Nicks procedure in a preclinical model.

We demonstrate the Nicks operation, one of the posterior aortic root enlargement procedures, on a preclinical model (porcine heart). The goal of this operation is to facilitate the implementation of a suitably sized aortic prosthetic valve. The procedure is performed by making a longitudinal incision through the non-coronary sinus without entering the fibrous body between the aortic valve and the anterior leaflet of the mitral valve and inserting a patch to enlarge the annulus.

Mid-Term Clinical Outcomes and Hemodynamic Performances of Trifecta and Perimount Bioprostheses following Aortic Valve Replacement.

Aims of the Study: We evaluated the clinical outcome and the hemodynamic and freedom from structural valve degeneration of two standard aortic bioprostheses. Methods: Clinical results, echocardiographic findings and follow-up data of patients operated for isolated or combined aortic valve replacement with the Perimount or the Trifecta bioprosthesis were prospectively collected, retrospectively analysed and compared. We weighted all the analyses by the inverse of the propensity of choosing either valves. Results: Between April 2015 and December 2019, 168 consecutive patients (all comers) underwent aortic valve replacement with Trifecta (n = 86) or Perimount (n = 82) bioprostheses. Mean age was 70.8 ± 8.6 and 68.8 ± 8.6 years for the Trifecta and Perimount groups, respectively (p = 0.120). Perimount patients presented a greater body mass index (27.6 ± 4.5 vs. 26.0 ± 4.2; p = 0.022), and 23% of them suffered from angina functional class 2-3 (23.2% vs. 5.8%; p = 0.002). Mean ejection fraction was 53.7 ± 11.9% (Trifecta) and 54.5 ± 10.4% (Perimount) (p = 0.994), with mean gradients of 40.4 ± 15.9 mmHg (Trifecta) and 42.3 ± 20.6 mmHg (Perimount) (p = 0.710). Mean EuroSCORE-II was 7 ± 11% and 6 ± 9% for the Trifecta and Perimount group, respectively (p = 0.553). Trifecta patients more often underwent isolated aortic valve replacement (45.3% vs. 26.8%; p = 0.016) and annulus enlargement (10.5% vs. 2.4%; p = 0.058). All-cause mortality at 30 days was 3.5% (Trifecta) and 8.5% (Perimount), (p = 0.203) while new pacemaker implantation (1.2% vs. 2.5%; p = 0.609) and stroke rate (1.2% vs. 2.5%; p = 0.609) were similar. Acute MACCE were observed in 5% (Trifecta) and 9% (Perimount) of patients with an unweighted OR of 2.22 (95%CI 0.64-7.66; p = 0.196) and a weighted OR of 1.10 (95%CI: 0.44-2.76, p = 0.836). Cumulative survival at 24 months was 98% (95%CI: 0.91-0.99) and 96% (95%CI: 0.85-0.99) for Trifecta and Perimount groups, respectively (log-rank test; p = 0.555). The 2-year freedom from MACCE was 94% (95%CI: 0.65-0.99) for Trifecta and 96% (95%CI: 0.86-0.99) for Perimount (log-rank test; p = 0.759, HR 1.46 (95%CI: 0.13-16.48)) in the unweighted analysis (not estimable in the weighted analysis). During the follow-up (median time: 384 vs. 593 days; p = 0.0001) there were no re-operations for structural valve degeneration. Mean valve gradient at discharge was lower for Trifecta across all valve sizes (7.9 ± 3.2 vs. 12.1 ± 4.7 mmHg; p < 0.001), but the difference did not persist during follow-up (8.2 ± 3.7 mmHg for Trifecta, 8.9 ± 3.6 mmHg for Perimount; p = 0.224); Conclusions: Postoperative outcome and mid-term follow-up were similar. An early better hemodynamic performance was detected for the Trifecta valve but did not persist over time. No difference in the reoperation rate for structural valve degeneration was found.

Long-Term Outcomes and Risk Factors Analysis for Patients Undergoing Thoracic Endovascular Aorta Repair (TEVAR), According to the Aortic Pathologies.

BACKGROUND: Thoracic endovascular aortic repair (TEVAR) has become a standard treatment for acute and chronic thoracic aorta diseases. We analyzed long-term outcomes and risk factors of TEVAR procedures according to the aortic pathology. METHODS: Demographics, indications, technical details, and outcomes of patients undergoing TEVAR procedures in our institutions were prospectively collected and retrospectively analyzed. Overall survival was determined using Kaplan-Meier methods while log-rank tests were used to compare the survival between groups. Cox regression analysis was used to identify risk factors. RESULTS: Between June 2002 and April 2020, 116 patients underwent TEVAR for different thoracic aorta diseases. Among them, 47 patients (41%) underwent TEVAR for aneurysmatic aortic disease, 26 (22%) for type-B aortic dissection, 23 (20%) for penetrating aortic ulcer, 11 (9%) after previous type-A dissection treatment, and 9 (8%) for traumatic aortic injury. Patients with posttraumatic aortic injury were younger (P < 0.01) with less hypertension (P < 0.01), diabetes (P < 0.01), and prior cardiac surgery (P < 0.01). Survival was different based on indication for TEVAR (log rank 0.024). Patients after previous type-A dissection treatment had the worst survival rate (50% at 5 years) while survival for aneurysmatic aortic disease was 55% at 5 years. No late death occurred in the traumatic group. Cox-regression model identified independent predictors for mortality: age (hazard ratio [HR]: 1.05, 95% confidence interval [CI]: 1.01-1.09, P = 0.006), male gender (HR: 3.2, 95% CI: 1.1-9.2, P = 0.028), moderate chronic obstructive pulmonary disease (HR: 2.1, 95% CI: 1.02-4.55, P = 0.043), previous cardiac surgery (HR: 2.1, 95% CI: 1.008-4.5, P = 0.048), and treatment indication for aneurysm (HR: 2.6, 95% CI: 1.2-5.2, P = 0.008). CONCLUSIONS: TEVAR is a safe and effective procedure with excellent long-term results in case of traumatic aortic injury. The overall long-term survival is affected by aortic pathology, associated comorbidities, gender, and previous cardiac surgery.

Cardiac surgery simulation: Step-by-step hemi-Yacoub operation in a preclinical model.

We demonstrate a hemi-Yacoub operation on a preclinical model (porcine heart). It is an alternative remodelling technique for the management of dilatation of the ascending aorta with the involvement of the aortic root, particularly the noncoronary sinus or in case of an aortic dissection. The goal of this operation is to replace selectively the dilated/dissected portion (noncoronary sinus), thereby avoiding replacement of the entire aortic root.

Resection of thymic carcinoma after induction therapy and reconstruction of right ventricular outflow tract with pulmonary homograft.

Treatment of malignant epithelial thymic tumours, including thymoma and thymic carcinoma, is based on surgical resection, whenever possible. Mainstay of surgical treatment is complete resection with clear margins. This may require resection of adjacent structures, even major vessels. We describe a case of resection of the main pulmonary artery trunk and reconstruction with cadaveric homograft after induction chemo-radiotherapy for a locally advanced thymic carcinoma. Written informed consent was obtained from the patient.

Ten-Year Experience with Transapical and Direct Transaortic Transcatheter Aortic Valve Replacement to Address Patients with Aortic Stenosis and Peripheral Vascular Disease.

Objective: Transcatheter aortic valve replacement (TAVR) through alternative access routes is indicated in patients with severe aortic valve stenosis and diseased peripheral arteries. We analysed and compared the outcome of patients undergoing transapical (TA) and direct transaortic (TAO) TAVR procedures. Methods: Preoperative characteristics, procedural details, and thirty-day outcome of patients undergoing transapical (TA-TAVR group) and direct transaortic (TAO-TAVR group) TAVR procedures were prospectively collected and retrospectively analysed. Results: From March 2012 to March 2022, 81 TA and 82 TAO-TAVR (total: 163 cases) were performed with balloon-expanding (n = 120; 73.6%) and self-expandable (n = 43; 26.4%) valves. The mean age was 79.7 ± 6.2 and 81.9 ± 6.7 years for the TA- and TAO-TAVR groups, respectively (p = 0.032). Females were more represented in the TAO-TAVR group (56% vs. 32%; p = 0.003) while TA-TAVR patients showed a higher prevalence of previous vascular surgery (20% vs. 6%; p = 0.01), previous cardiac surgery (51% vs. 3.6%; p < 0.001), and porcelain aorta (22% vs. 5%; p = 0.001). The mean ejection fraction was 49.0 ± 14.6% (TA) and 53.5 ± 12.2% (TAO) (p = 0.035) while mean gradients were 35.6 ± 13.2 mmHg (TA) and 40.4 ± 16.1 mmHg (TAO) (p = 0.045). The median EuroSCORE-II was 5.0% (IQR: 3.0−11.0) and 3.9% (IQR: 2.5−5.4) for the TA- and TAO-TAVR groups, respectively (p = 0.005). The procedural time was shorter for TA procedures (97 min (IQR: 882−118) vs. 102 min (IQR: 88−129); p = 0.133). Mortality at day 30 was 6% in both groups (p = 1.000); the permanent pacemaker implantation rate was similar (8.6% vs. 9.7%; p = 1.000), and hospital stay was shorter for the TAO group (8 days (IQR: 6−11) vs. 10 days (IQR: 7−13); p = 0.025). Conclusions: Our results show that transapical and direct transaortic TAVR in high-risk patients with diseased peripheral arteries provide satisfactory clinical results with similar thirty-day outcomes.

Cardiac surgery simulation - part 1: Step-by-step David procedure in a preclinical model.

We performed this operation on a preclinical model (porcine heart) that has been positioned and fixed inside a plastic mannequin that simulates the human anatomy. This simulation allows surgical operations to be performed at almost the same depth and orientation at which they would be performed on a patient in an operating room. The preclinical model allows the exact simulation of most of the key movements and steps of major coronary and valve surgery. In this case, we show the salient steps of the David I operation.

Twenty-year experience with skeletonized bilateral internal thoracic arteries for surgical myocardial revascularization. A single center experience.

BACKGROUND AND AIM OF THE STUDY: The mammary artery shows excellent long-term patency and encourages the use of skeletonized bilateral internal thoracic arteries (BITA) for coronary surgery. We analyzed the long-term outcome of patients operated for myocardial revascularization with BITA in a single center. MATERIALS AND METHODS: Clinical data and surgical details of patients undergoing coronary surgery with BITA were prospectively collected and retrospectively analyzed. Selected variables were studied as risk factors for sternal wound complication and a subanalysis of clinical outcome for patients aged 70 years or greater was performed. A long-term follow-up of the study group is provided. RESULTS: From January 2001 to November 2021, 750 patients underwent myocardial revascularization using BITA grafts (mean age: 61 ± 9.5 years; males: 91%) at our institute. Patients with triple-vessel disease were 81%, 15.3% of all procedures were performed off-pump and 3.6% were urgent cases. Hospital mortality was 0.5%. Sternal wound complication was observed in 67 patients (9.0%) with 7 deep sternal wound infections (0.9%). Female gender (odds ratios [OR]: 3.7, p < 0.01), BMI >30 (OR: 1.8, p = 0.04), smoking (OR: 1.8, p = 0.02), and chronic kidney failure (OR: 3.7, p = 0.05) were independent predictors for sternal complications. During a mean follow-up time of 8.7 ± 5.3 years, 34 patients (4.5%) underwent a repeated myocardial revascularization, and there were 89 all-cause deaths (11.9%) and the cumulative survival at 5, 10, 15, and 20 years was 97%, 89%, 76%, and 60% for the whole study group 92%, 74%, 47%, and 43% for the subgroup of elderly patients (mean age: 74 ± 3.5 years). CONCLUSIONS: Use of skeletonized bilateral thoracic arteries shows low-rate of wound infection and good long-term outcome with low risk of repeated revascularizations, regardless of patients' age.

Transcatheter mitral valve replacement in native mitral valve with severe mitral annular calcification: Skirting the Sapien 3 to reduce the risk of paravalvular leaks.

Background: Mitral annular calcification (MAC) may represent a significant challenge for heart surgeons with an extremely high perioperative risk during mitral valve (MV) surgery. The risk is further increased when patients fail to be eligible for any percutaneous treatment, particularly because circumferential calcifications involving the anterior leaflet suggest a critical obstruction of the left ventricular outflow tract (LVOT). Objectives: The objective of this study was to evaluate residual mitral regurgitation (MR) after surgical mitral valve replacement using a Sapien 3 Ultra (Edwards Lifesciences, CA, USA) transcatheter aortic valve implantation (TAVI) prosthesis, reinforced with a pericardial skirt, in high-risk selected patients with severe MAC. Methods: Since 2020, five high-risk patients (mean age 70 years; 63-76; four women) with severe mitral disease in the context of severe MAC (computed tomography-based mean MAC Score 8.2 ± 1.1) were operated on after we adopted this novel technique. The operations were performed under general anesthesia, using a transapical TAVI delivery system to position the Sapien 3 in the mitral position under direct vision. To reinforce and avoid paravalvular leakages, a pericardial skirt was previously sewn around the prosthesis, securing it to the annulus and perivalvular atrial surface. Results: Sapien 3 Ultra implantation was successful without residual MR in all five patients (mild paravalvular leak in one case). Four patients had a 29-mm valve implanted, while one had a 26-mm valve implanted. Predilatation of the native annulus was never performed. Perfusion and clamping times were 134 ± 53 mins and 108 ± 43 mins, respectively. The presence of the pericardial skirt reduced the risk of leakage between the prosthesis and the rigid calcium surface, with final mean and maximal gradients of the TAVI prosthesis of 4.1 and 10.8 mmHg, respectively. There were no left ventricular outflow tract obstructions (mean LVOT gradient of 8 ± 1 mmHg). All patients were discharged, and neither mortality nor prosthetic dysfunction, nor residual mitral regurgitation was recorded. During follow-up, the last patient treated (MAC Score 10, severe calcification of the mitro-aortic junction) returned to our attention with a significant recurrent jet originating from the anterolateral commissure, currently medically treated, given the prohibitive redo risk. Conclusion: Direct open surgical implantation of the Sapien 3 valve can be safely done in patients with severe MAC in dedicated centers. Reinforcing the TAVI prosthesis by sewing a pericardial skirt led to satisfactory perioperative and early postoperative results, reducing paravalvular leakages. Complex anatomies have a CERTAIN risk of recurrence.

Patient tilt improves efficacy of CO2 field-flooding in minimally invasive cardiac surgery.

OBJECTIVE: Space limitations during minimally invasive cardiac surgery impede consistent use of CO2 field-flooding. We compared different gas delivery methods, flow rates and the effect of patient inclination. METHODS: A gastight model of MICS surgery with internal organs and right thoracotomy wound was created from a mannequin and equipped with a CO2 concentration sensor in the left ventricle. Maximum achievable CO2 concentration was compared for gas delivery via three commercial CO2 diffusors (CarbonMini, Temed, Andocor) and also via a trocar with side port. Gas flow rates of 1, 3, 5 and 8 L per minute were tested. The model was placed either in supine position or with 20° oblique tilt. A simplified transparent model was also created and placed in an optical test bench to evaluate the gas cloud motions via real-time visualization. RESULTS: The trocar consistently achieved higher CO2 concentrations inside the left ventricle. At 1 l/min, approximately 2.5 min were needed to fill the supine model to its maximum CO2 concentration, which was limited to a range of 48-82% in the left ventricle. At higher flow rates, filling time and concentration were significantly improved. In a tilted model, all devices and all flow rates generated on average 99% CO2 in the ventricle. Imaging revealed constant gas exchange via the main incision, with CO2 outflow via bottom and air inflow via the top of the incision. CONCLUSIONS: CO2 field flooding in minimally invasive cardiac surgery is highly effective if the patient is tilted. Else a flow rate of 5 l/min is recommended to achieve the same protection.

Percutaneous Venous Cannulation for Minimally Invasive Cardiac Surgery: The Safest and Effective Technique Described Step-by-Step.

The current cardiac surgical landscape, with the expansion of minimally invasive operations, ECMO, and some interventional therapies, requires a thorough knowledge of peripheral cannulation techniques. In particular, venous cannulation may appear trivial and complication-free, but this does not reflect the reality. A venous cannulation which is not perfectly performed can lead to serious life-threatening complications in several steps. The technique we describe step by step is the current gold standard in terms of safety and efficacy: from the use of ultrasound for ultrasound-guided puncture to safe advancement of super stiff guidewires by means of a sentinel catheter, and concluding with smooth insertion of the venous cannula over the stiff guidewire up to the SVC. Moreover, a list of bailout maneuvers to solve complications is presented along with a report of institutional clinical experience since the adoption of this technique.

The use of balloon-expandable Sapien-3 valve in redo aortic valve replacement and the potential risk of left main stem occlusion.

Redo aortic valve surgery for the failure of a previously implanted valve is always challenging. In case of small-sized implanted valves, the use of a balloon-expanding Sapien-3 valve can enhance the final effective orifice area, avoid annulus enlargement complex techniques, and can reduce operative time and morbidities. We describe a case where after explanting a failed 19 mm St. Jude mechanical aortic valve and further deployment of a 23 mm Sapien-3 valve, the left coronary ostia was obstructed by the skirt of the transcatheter prosthesis. After careful removal of a little part of the skirt, we were able to restore the coronary flow and the patient had a favorable outcome.

Embedded Computational Heart Model for External Ventricular Assist Device Investigations.

PURPOSE: External cardiac assist devices are based on a promising and simple concept for treating heart failure, but they are surprisingly difficult to design. Thus, a structured approach combining experiments with computer-based optimization is essential. The latter provides the motivation for the work presented in this paper. METHODS: We present a computational modeling framework for realistic representation of the heart's tissue structure, electrophysiology and actuation. The passive heart tissue is described by a nonlinear anisotropic material law, considering fiber and sheetlet directions. For muscle contraction, an orthotropic active-strain model is employed, initiated by a periodically propagating electrical potential. The model allows for boundary conditions at the epicardium accounting for external assist devices, and it is coupled to a circulation network providing appropriate pressure boundary conditions inside the ventricles. RESULTS: Simulated results from an unsupported healthy and a pathological heart model are presented and reproduce accurate deformations compared to phenomenological measurements. Moreover, cardiac output and ventricular pressure signals are in good agreement too. By investigating the impact of applying an exemplary external actuation to the pathological heart model, it shows that cardiac patches can restore a healthy blood flow. CONCLUSION: We demonstrate that the devised computational modeling framework is capable of predicting characteristic trends (e.g. apex shortening, wall thickening and apex twisting) of a healthy heart, and that it can be used to study pathological hearts and external activation thereof.

Gaseous Microemboli in the Cardiopulmonary Bypass Circuit: Presentation of a Systematic Data Collection Protocol Applied at Istituto Cardiocentro Ticino.

Air emboli are reported to enter the cardiovascular system during cardiac surgery despite air-bubble filters in the arterial line of the cardiopulmonary bypass (CPB). A potential association with stroke, covert cerebral insults and cognitive decline after cardiac surgery has been hypothesized. Although most of the previous studies failed to prove it, this hypothesis cannot be rejected because the situation in the operating room (OR) is multifactorial and complex. Therefore, rigorous and standardized protocols are needed to investigate sources, patterns, as well as effective quantity and volume of air embolism.  We hereby present our protocol in detail for systematic data collection as a standard quality control measure at our center, where air bubbles in the cardiopulmonary bypass circuit are measured by a commercial bubble counter. We also show a preview of the type of information that can be obtained for future analysis. The eventual aim is to determine a potential association between air emboli and adverse postoperative outcomes, as well as to identify major sources of air bubbles generation and in the long run to find effective prevention strategies.