The latest medical research on Cardiothoracic Surgery

The research magnet gathers the latest research from around the web, based on your specialty area. Below you will find a sample of some of the most recent articles from reputable medical journals about cardiothoracic surgery gathered by our medical AI research bot.

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Stent and leaflet stresses across generations of balloon-expandable transcatheter aortic valves.

Interactive Cardiovascular and Thoracic Surgery

Transcatheter aortic valve replacement (TAVR) is established therapy for severe aortic stenosis patients with intermediate-, high- and prohibitive-risk for surgery. A significant challenge when expanding TAVR to low-risk and younger patients is the unknown long-term durability. High leaflet stresses have been associated with surgical bioprosthetic valve degeneration. In this study, we examined the impact of changes in valve design across 3 generations of same-sized TAVR devices on stent and leaflet stresses.

The 26-mm Edwards SAPIEN, 23, 26 and 29 mm SAPIEN XT (XT) and 26 mm SAPIEN 3 (S3) (n = 1 each) underwent micro-computed tomography (micro-CT) scanning. Dynamic finite element computational simulations of 23-26 mm SAPIEN, 23-29 mm XT and 23-29 mm S3 were performed with physiological loading and micro-CT or scaled geometries.

Peak stresses were concentrated in the commissure area and along the bottom of the suture, representing areas most likely to develop structural valve degeneration across TAVR generations. Latest-generation S3 showed greatest 99th percentile principal stress on commissural leaflets for 26 and 29 mm, and increased stresses over XT for 23 mm. Percentage of higher stress areas within the leaflets steadily increased across generations, 3.8%, 3.9% and 5.7%, respectively, for 26 mm SAPIEN, XT and S3 with similar trend for 29-mm valves.

Using computational simulations based on high-fidelity modelling of balloon-expandable TAVRs, our study demonstrated that maximum stress areas existed in similar leaflet locations across SAPIEN generations, while the latest model S3 had the highest magnitude for both 26- and 29-mm valves. S3 also had the largest area of higher stresses than other generations, which would be prone to degeneration. Our study coupled with future long-term clinical outcomes >10 years will provide insight on biomechanics of TAVR degeneration.

Association of previous cardiac surgery with outcomes in left ventricular assist device patients.

Interactive Cardiovascular and Thoracic Surgery

History of prior cardiac surgery has traditionally been considered a risk factor for subsequent cardiac procedures. The aim of this study was to investigate the outcomes of patients implanted with a left ventricular assist device via redo sternotomy.

Prospectively collected data were reviewed for all patients implanted with a continuous-flow left ventricular assist device at a single institution from December 2006 through June 2018. Patients were separated into 2 cohorts: those with a history of prior cardiac surgery (redo sternotomy) and those undergoing primary sternotomy at the time of left ventricular assist device implantation. The primary outcome was overall survival.

Of the 321 patients included in the study, 77 (24%) were implanted via redo sternotomy and 244 (76%) via primary sternotomy. The redo sternotomy cohort was generally older (59 ± 10 vs 57 ± 12 years, P = 0.050) and had a higher incidence of ischaemic disease (70% vs 49%, P = 0.002). The Kaplan-Meier survival analysis demonstrated that overall survival was not significantly different between the redo sternotomy and primary sternotomy groups (6-month survival: 86% vs 92%; 5-year survival: 53% vs 51%; log-rank P = 0.590 for overall difference during follow-up). The propensity score analysis consistently showed that redo sternotomy was not significantly associated with mortality risk (hazard ratio 1.19, 95% confidence interval 0.73-1.93; P = 0.488). Redo sternotomy patients were more likely to require rehospitalization during their first year postoperatively (P = 0.020) and spent less time out of the hospital during the first year (P = 0.046).

The redo sternotomy cohort represents a more technically challenging patient population, but overall survival similar to that of primary sternotomy patients can be achieved.

Partial lung resection by uniportal video-assisted thoracoscopic surgery: technique and pitfalls.

European Journal of Heart Failure

The use of uniportal video-assisted thoracoscopic surgery (VATS) has increased worldwide. The number of facilities introducing this simple and cost...

Watch-and-wait strategy for type A intramural haematoma and acute aortic dissection with thrombosed false lumen of the ascending aorta: a Japanese single-centre experience.

European Journal of Heart Failure

In this study, we investigated the early and midterm outcomes of initial watch-and-wait strategy for Stanford type A intramural haematoma and acute aortic dissection with thrombosed false lumen of the ascending aorta in patients with a maximum aortic diameter of ≤50 mm, pain score of ≤3/10 and no ulcer-like projection in the ascending aorta.

Inpatient and outpatient records were retrospectively reviewed.

Of the 81 patients with type A intramural haematoma and acute aortic dissection with the thrombosed false lumen of the ascending aorta between April 2011 and April 2019, a watch-and-wait strategy was selected in 46 patients. The mean age of the patients was 68 years, and 22 (48%) patients were female. Ten patients underwent emergency pericardial drainage for cardiac tamponade at the time of presentation and 8 patients underwent aortic repair during hospitalization for new ulcer-like projection, re-dissection or rupture. In-hospital mortality occurred in 2 (4%) patients. During follow-up, survival at 1 and 2 years was 95% and 92%, respectively. There was no significant difference in survival or aortic events between patients in whom the watch-and-wait strategy and emergency surgical treatment were indicated.

The early and midterm outcomes of the initial watch-and-wait strategy were favourable for type A intramural haematoma and acute aortic dissection with the thrombosed false lumen of the ascending aorta in Japanese patients with a maximum aortic diameter of ≤50 mm, pain score of ≤3/10 and no ulcer-like projection. Further study is required to show the safety of this strategy.

Aortic valve-sparing root replacement in patients with bicuspid aortic valve: long-term outcome with the David I procedure over 20 years.

European Journal of Heart Failure

Aortic valve-sparing root replacement is an excellent treatment option for patients with intact tricuspid aortic valves. However, the durability in patients with bicuspid aortic valves is still a matter of debate. The aim of this study was to analyse the short- and long-term outcomes in patients with bicuspid aortic valves.

Between July 1993 and October 2015, a total of 582 patients underwent the David I procedure, 50 of whom had a bicuspid aortic valve. In these patients, the mean age was 46 ± 13 years, and 80% (n = 40) were men. Follow-up was complete for 100% of patients and comprised a total of 552 patient-years with a mean follow-up time of 11 ± 5.2 years.

In addition to the David procedure, cusp plication was performed in 34% (n = 17) of patients and commissure repair in 8% (n = 4) of patients. There were no in-hospital deaths, and 1 patient (2%) had a perioperative stroke. The 1-, 5-, 10- and 20-year survival rates of patients after discharge were 98%, 94%, 88% and 84%, respectively. The rates for freedom from valve-related reoperation at 1, 5, 10 and 20 years after initial surgery were 98%, 88%, 79% and 74%, respectively. Long-term freedom from reoperation was comparable to that of patients with tricuspid aortic valves (P = 0.2).

The David procedure has excellent short-term results in patients with a bicuspid aortic valve. In this study, the long-term durability of reimplanted bicuspid aortic valves was comparable to that of tricuspid valves. However, careful patient selection might have contributed to this, and further studies might be needed to definitely clarify this issue.

Surgical correction of coarctation of the aorta featuring an incomplete circle of Willis.

Interactive Cardiovascular and Thoracic Surgery

Although devastating complications during simple coarctation of aorta repair now occur less frequently, some unique cases still require extra cauti...

Does routine fenestration improve early and late postoperative outcomes in patients undergoing Fontan palliation?

Interactive Cardiovascular and Thoracic Surgery

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: 'In [patients undergoing Fonta...

The impact of cardiopulmonary bypass management on outcome: a propensity matched comparison between minimally invasive and conventional valve surgery.

Interactive Cardiovascular and Thoracic Surgery

Research concerning cardiopulmonary bypass (CPB) management during minimally invasive cardiac surgery (MICS) is scarce. We investigated the effect of CPB parameters such as pump flow, haemoglobin concentration and oxygen delivery on clinical outcome and renal function in a propensity matched comparison between MICS and median sternotomy (MS) for atrioventricular valve surgery.

A total of 356 patients undergoing MICS or MS for atrioventricular valve surgery between 2006 and 2017 were analysed retrospectively. Propensity score analysis matched 90 patients in the MS group with 143 in the MICS group. Logistic regression analysis was performed to investigate independent predictors of cardiac surgery-associated acute kidney injury in patients having MICS.

In MICS, CPB (142.9 ± 39.4 vs 101.0 ± 38.3 min; P < 0.001) and aortic cross-clamp duration (89.9 ± 30.6 vs 63.5 ± 23.0 min; P < 0.001) were significantly prolonged although no differences in clinical outcomes were detected. The pump flow index was lower [2.2 ± 0.2 vs 2.4 ± 0.1 l⋅(min⋅m2)-1; P < 0.001] whereas intraoperative haemoglobin levels were higher (9.25 ± 1.1 vs 8.8 ± 1.2; P = 0.004) and the nadir oxygen delivery was lower [260.8 ± 43.5 vs 273.7 ± 43.7 ml⋅(min⋅m2)-1; P = 0.029] during MICS. Regression analysis revealed that the nadir haemoglobin concentration during CPB was the sole independent predictor of cardiac surgery-associated acute kidney injury (odds ratio 0.67, 95% confidence interval 0.46-0.96; P = 0.029) in MICS but not in MS.

Specific cannulation-related issues lead to CPB management during MICS being confronted with flow restrictions because an average pump flow index ≤2.2 l/min/m2 is achieved in 40% of patients who have MICS compared to those who have a conventional MS. This study showed that increasing the haemoglobin level might be helpful to reduce the incidence of cardiac surgery-associated acute kidney injury after minimally invasive mitral valve surgery.

Study of the time-relationship of the mechano-electrical interaction in an animal model of tetralogy of Fallot: implications for the risk assessment of ventricular arrhythmias.

Interactive Cardiovascular and Thoracic Surgery

The long-term outcome of tetralogy of Fallot (TOF) is determined by progressive right ventricular (RV) dysfunction through pulmonary regurgitation (PR) and the risk of malignant arrhythmia. Although mechano-electrical coupling in TOF is well-known, its time effect on the inducibility of arrhythmia remains ill-defined. The goal of this study was to investigate the mechano-electrical properties at different times in animals with chronic PR.

PR was induced by a transannular patch with limited RV scarring in infant pigs. Haemodynamic assessment included biventricular pressure-volume loops after 3 (n = 8) and 6 months (n = 7) compared to controls (n = 5). The electrophysiological study included endocardial monophasic action potential registration, intraventricular conduction velocity and induction of ventricular arrhythmia by burst pacing.

Progressive RV dilation was achieved at 6 months (RV end-diastolic volume 143 ± 13 ml/m2-RV end-systolic volume 96 ± 7 ml/m2; P < 0.001), in association with depressed RV contractility (preload recruitable stroke work-slope: 19 ± 1 and 11 ± 3 Mw.ml-1.s-1 for control and 6 m; P < 0.001) and left ventricular contractility (preload recruitable stroke work-slope: 60 ± 13 and 40 ± 11 Mw.ml-1.s-1 for control and 6 m; P = 0.005). Concomitant to QRS prolongation, monophasic action potential90-duration and dispersion at the RV and left ventricle were increased at 6 months. Intraventricular conduction was delayed only in the RV at 6 months (1.8 ± 0.2 and 2.4 ± 0.6 m/s for group 6M and the control group; P = 0.035). Sustained ventricular arrhythmias were not inducible.

In animals yielding the sequelae of a contemporary operation for TOF, mechano-electrical alterations are progressive and affect predominantly the RV after midterm exposure of PR. Because ventricular arrhythmias were not inducible despite significant RV dilation, the data suggest that the haemodynamic RV deterioration effectively precedes the risk of inducing sustained arrhythmia after TOF repair and opens a window for renewed stratification of contemporary risk factors of ventricular arrhythmias in patients operated on with currently used pulmonary valve- and RV-related techniques.

Quality of Surgery and Outcome in Localized Gastrointestinal Stromal Tumors Treated Within an International Intergroup Randomized Clinical Trial of Adjuvant Imatinib.

JAMA Surgery

The association between quality of surgery and overall survival in patients affected by localized gastrointestinal stromal tumors (GIST) is not completely understood.

To assess the risk of death with and without imatinib according to microscopic margins status (R0/R1) using data from a randomized study on adjuvant imatinib.

This is a post hoc observational study on patients included in the randomized, open-label, phase III trial, performed between December 2004 and October 2008. Median follow-up was 9.1 years (IQR, 8-10 years). The study was performed at 112 hospitals in 12 countries. Inclusion criteria were diagnosis of primary GIST, with intermediate or high risk of relapse; no evidence of residual disease after surgery; older than 18 years; and no prior malignancies or concurrent severe/uncontrolled medical conditions. Data were analyzed between July 17, 2017, and March 1, 2020.

Patients were randomized after surgery to either receive imatinib (400 mg/d) for 2 years or no adjuvant treatment. Randomization was stratified by center, risk category (high vs intermediate), tumor site (gastric vs other), and quality of surgery (R0 vs R1). Tumor rupture was included in the R1 category but also analyzed separately.

Primary end point of this substudy was overall survival (OS), estimated using Kaplan-Meier method and compared between R0/R1 using Cox models adjusted for treatment and stratification factors.

A total of 908 patients were included; 51.4% were men (465) and 48.6% were women (440), and the median age was 59 years (range, 18-89 years). One hundred sixty-two (17.8%) had an R1 resection, and 97 of 162 (59.9%) had tumor rupture. There was a significant difference in OS for patients undergoing an R1 vs R0 resection, overall (hazard ratio [HR], 2.05; 95% CI, 1.45-2.89) and by treatment arm (HR, 2.65; 95% CI, 1.37-3.75 with adjuvant imatinib and HR, 1.86; 95% CI, 1.16-2.99 without adjuvant imatinib). When tumor rupture was excluded, this difference in OS between R1 and R0 resections disappeared (HR, 1.05; 95% CI, 0.54-2.01).

The difference in OS by quality of surgery with or without imatinib was associated with the presence of tumor rupture. When the latter was excluded, the presence of R1 margins was not associated with worse OS.

ClinicalTrials.gov Identifier: NCT00103168.

Association of Personality and Thinking Style With Effective Surgical Coaching.

JAMA Surgery

While interest in surgical coaching programs is rising, there is no objective method for selecting effective surgical coaches.

To identify a quantitative measure to determine who will be an effective surgical coach.

This prospective cohort study included coaches and coachees from 2 statewide peer surgical coaching programs: the Wisconsin Surgical Coaching Program and the Michigan Bariatric Surgical Collaborative coaching program. Data were collected from April 2014 to February 2018, and analysis began August 2018.

The Myers-Briggs Type Indicator was administered to coaches and coachees, and the Life Styles Inventory was administered to surgical coaches before their first coaching session.

Coach performance in the first coaching session and all coaching sessions using the Wisconsin Surgical Coaching Rubric.

Twenty-three surgical coaches and 38 coachees combined for a total of 65 unique pairs and 106 coaching sessions. Overall, 22 of 23 coaches (96%) and 32 of 38 coachees (84%) were men. An increase in a coach's Life Styles Inventory constructive style score correlated with an increase in overall coach performance for the first coaching session (r = 0.70; P = .002). Similarity in the coaching pair's Myers-Briggs Type Indicator judging/perceiving dichotomy was also associated with an increase in overall coach performance for their first coaching session (β = 0.38; P = .02). When all sessions were included in the analysis, these objective measures were no longer associated with coach performance.

Surgeons of all personalities and thinking styles can become an effective coach with appropriate training and experience. Coach training can be tailored to support diverse behavioral styles and preferences to maximize coach effectiveness.

Preoperative determination of artificial chordae tendineae length by transoesophageal echocardiography in totally endoscopic mitral valve repair.

Interactive Cardiovascular and Thoracic Surgery

Artificial chordae tendineae are widely used for surgical repair in patients with mitral regurgitation due to floppy mitral valve/mitral valve prolapse. Expanded polytetrafluoroethylene has been used to construct these artificial chordae; however, the determination of the optimal length of the chordae prior to surgery has been an issue. For this reason, such a method was developed and the results of its use are presented.

Forty-seven consecutive patients with significant mitral regurgitation due to floppy mitral valve/mitral valve prolapse who underwent totally endoscopic mitral valve surgery were studied. The chordae length was predetermined using transoesophageal echocardiography. The length between the top of the fibrous body of the papillary muscle and the coaptation line of the 2 leaflets of the mitral valve was measured and used to define the length of the chordae to be used for repair. Then under stereoscopic vision, a total endoscopic mitral valve repair was performed.

The predicted mean length of chordal loops was 19.76 ± 0.71 mm (median 20, range 16-28) and the actual mean length of chordal loops used was 19.68 ± 0.74 mm (median 20, range 16-26) demonstrating an excellent correlation between the two (r = 0.959). The mean number of chordae loops used per patient was 5.12 ± 0.62 (median 4, range 2-12). All patients at the time of discharge had no or trivial mitral regurgitation on transoesophageal echocardiography.

The chordae length used for mitral valve repair can be determined prior to surgery using transoesophageal echocardiography with a high degree of accuracy. Further, total endoscopic repair in this group of patients provides excellent results. For these reasons, it is expected that this method will replace most traditional approaches to cardiac surgeries in the years to come.