Should less-invasive aortic valve replacement be avoided in patients with pulmonary dysfunction?

Comparative Evaluation of the Incidence of Postoperative Pulmonary Complications After Minimally Invasive Valve Surgery vs. Full Sternotomy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials and Propensity Score-Matched Studies

Background: Postoperative pulmonary complications remain a leading cause of increased morbidity, mortality, longer hospital stays, and increased costs after cardiac surgery; therefore, our study aims to analyze whether minimally invasive valve surgery (MIVS) for both aortic and mitral valves can improve pulmonary function and reduce the incidence of postoperative pulmonary complications when compared with the full median sternotomy (FS) approach. Methods: A comprehensive systematic literature research was performed for studies comparing MIVS and FS up to February 2021. Randomized controlled trials (RCTs) and propensity score-matching (PSM) studies comparing early respiratory function and pulmonary complications after MIVS and FS were extracted and analyzed. Secondary outcomes included intra- and postoperative outcomes. Results: A total of 10,194 patients from 30 studies (6 RCTs and 24 PSM studies) were analyzed. Early mortality differed significantly between the groups (MIVS 1.2 vs. FS 1.9%; p = 0.005). Compared with FS, MIVS significantly lowered the incidence of postoperative pulmonary complications (odds ratio 0.79, 95% confidence interval [0.67, 0.93]; p = 0.004) and improved early postoperative respiratory function status (mean difference -24.83 [-29.90, -19.76]; p < 0.00001). Blood transfusion amount was significantly lower after MIVS (p < 0.02), whereas cardiopulmonary bypass time and aortic cross-clamp time were significantly longer after MIVS (p < 0.00001). Conclusions: Our study showed that minimally invasive valve surgery decreases the incidence of postoperative pulmonary complications and improves postoperative respiratory function status.

Planning for minimally invasive aortic valve replacement: key steps for patient assessment

Minimally invasive aortic valve replacement (MIAVR) has proved to be a safe approach for the treatment of aortic valve stenosis and/or insufficiency and is associated with a number of additional benefits for patients. This includes reduced blood loss, reduced transfusion requirements, reduced length of hospital stay and improved aesthetic appearance. As all types of minimally invasive surgery rely on optimizing exposure within a more limited field of view, a thorough preoperative assessment of patients is important to identify and address potential exposure problems. MIAVR through an upper hemisternotomy is considered feasible in almost every patient, but various clinical conditions or anatomical variations can complicate the procedure and may impact on the postoperative outcome. MIAVR through an anterior right thoracotomy requires suitable anatomy, and this should be evaluated preoperatively through a computed tomography or magnetic resonance imaging scan. In this review, we aimed to present an overview of the current literature and to reflect on our personal experiences with MIAVR techniques. This should provide an aid-especially to surgeons wanting to start or have little experience with MIAVR-for a structured preoperative patient assessment and planning to increase the chance of a safe procedure with a good outcome.

The incidence, predictive factors and prognosis of acute pulmonary complications after transcatheter aortic valve implantation

OBJECTIVES

Although acute pulmonary complications (APCs), such as the exacerbation of pulmonary disease (PD) or a newly developed pulmonary event, are thought to be catastrophic after invasive therapy, little is known about the occurrence of APCs after transcatheter aortic valve implantation (TAVI). This study aims to clarify the incidence, predictive factors and impact of APCs on prognosis after TAVI.

METHODS

We identified 749 patients who underwent TAVI, using data from the Optimized CathEter vAlvular iNtervention (OCEAN-TAVI) Japanese multicentre registry. APCs were defined as exacerbation of a comorbidity or newly developed PD during hospitalization. Patients were divided into 2 groups: an APC group (1.5%, 11/749) and a non-APC group (98.5%, 738/749). Clinical and prognostic outcomes were compared, and predictive factors for APCs were assessed.

RESULTS

Procedure-related death did not differ between the groups (0.4% vs 0.0%, P = 1.00), although 30-day mortality was significantly higher in the APC group than in the non-APC group (27.3% vs 1.6%, P = 0.001) and the difference in cumulative 1-year mortality increased further (72.7% vs 8.6%, log-rank test: P < 0.001). In particular, concomitant PD and transapical (TA) approach were identified as predictors of APCs after TAVI [univariable odds ratio (uOR) = 24.2, 95% confidence interval (CI) = 3.08-189.9, P = 0.002; uOR = 3.69, 95% CI = 1.11-12.3, P = 0.033, respectively].

CONCLUSIONS

Although rare, the occurrence of APCs after TAVI was associated with extremely poor prognosis. Patients undergoing TAVI with concomitant PD and/or TA require careful consideration to avoid the risk of APCs.

Minimally invasive aortic valve replacement in high risk patient groups

Minimally invasive aortic valve replacement (AVR) aims to preserve the sternal integrity and improve postoperative outcomes. In low risk patients, this technique can be achieved with comparable mortality to the conventional approach and there is evidence of possible reduction in intensive care and hospital length of stay, transfusion requirement, renal dysfunction, improved respiratory function and increased patient satisfaction. In this review, we aim to asses if these benefits can be transferred to the high risk patient groups. We therefore, discuss the available evidence for the following high risk groups: elderly patients, re-operative surgery, poor lung function, pulmonary hypertension, obesity, concomitant procedures and high risk score cohorts.

Function of the Respiratory System in Elderly Patients After Aortic Valve Replacement

OBJECTIVE

To compare the function of the respiratory system after aortic valve replacement through median sternotomy (AVR) or the minimally invasive right anterior minithoracotomy (RAT-AVR) approach among elderly (aged≥75 years) patients.

DESIGN

Observational cohort study.

SETTINGS

University hospital.

PARTICIPANTS

The study included 65 elderly patients scheduled for RAT-AVR and 82 for standard AVR.

INTERVENTIONS

Pulmonary function tests (PFT) were performed preoperatively, 1 week, 1 month, and 3 months after surgery. In addition, respiratory complications were analyzed.

MEASUREMENTS AND MAIN RESULTS

Respiratory complications occurred in 12.3% of patients in the RAT-AVR group and 18.3% of patients in the AVR group (p = 0.445). Mechanical ventilation time in the intensive care unit was 7.7±3.6 hours for RAT-AVR patients and 9.7±5.4 hours for AVR patients (p = 0.003). Most PFT were worse in the AVR group than in the RAT-AVR group when performed 1 week after surgery. After 1 month, forced expiratory volume in the first second, vital capacity, and total lung capacity differed significantly in favor of the RAT-AVR group (p = 0.002, p<0.001, and p = 0.001, respectively). After 3 months, the PFT parameters still had not returned to preoperative values, but the differences were no longer significant between the RAT-AVR and AVR groups. The multivariable median regression analysis demonstrated that RAT-AVR surgery was a key factor in a patient's higher postoperative PFT parameter values.

CONCLUSIONS

RAT-AVR surgery resulted in shorter postoperative mechanical ventilation time and improved the recovery of pulmonary function in elderly patients, but it did not reduce the incidence of pulmonary complications when compared with surgery performed through a median sternotomy.

Enhancing the Value of Population-Based Risk Scores for Institutional-Level Use

BACKGROUND

We hypothesized that factors associated with an institution's residual risk unaccounted for by population-based models may be identifiable and used to enhance the value of population-based risk scores for quality improvement.

METHODS

From January 2000 to January 2010, 4,971 patients underwent aortic valve replacement (AVR), either isolated (n = 2,660) or with concomitant coronary artery bypass grafting (AVR+CABG; n = 2,311). Operative mortality and major morbidity and mortality predicted by The Society of Thoracic Surgeons (STS) risk models were compared with observed values. After adjusting for patients' STS score, additional and refined risk factors were sought to explain residual risk. Differences between STS model coefficients (risk-factor strength) and those specific to our institution were calculated.

RESULTS

Observed operative mortality was less than predicted for AVR (1.6% [42 of 2,660] vs 2.8%, p < 0.0001) and AVR+CABG (2.6% [59 of 2,311] vs 4.9%, p < 0.0001). Observed major morbidity and mortality was also lower than predicted for isolated AVR (14.6% [389 of 2,660] vs 17.5%, p < 0.0001) and AVR+CABG (20.0% [462 of 2,311] vs 25.8%, p < 0.0001). Shorter height, higher bilirubin, and lower albumin were identified as additional institution-specific risk factors, and body surface area, creatinine, glomerular filtration rate, blood urea nitrogen, and heart failure across all levels of functional class were identified as refined risk-factor variables associated with residual risk. In many instances, risk-factor strength differed substantially from that of STS models.

CONCLUSIONS

Scores derived from population-based models can be enhanced for institutional level use by adjusting for institution-specific additional and refined risk factors. Identifying these and measuring differences in institution-specific versus population-based risk-factor strength can identify areas to target for quality improvement initiatives.

Early outcomes after isolated aortic valve replacement with rapid deployment aortic valve

OBJECTIVE

Minimal access aortic valve replacement is associated with favorable clinical outcomes; however, several meta-analyses have reported significantly longer crossclamp times compared with a full sternotomy. We examined the procedural and early safety outcomes after isolated rapid deployment aortic valve replacement by surgical approach in patients enrolled in the Surgical Treatment of Aortic Stenosis With a Next Generation Surgical Aortic Valve trial.

METHODS

The Surgical Treatment of Aortic Stenosis With a Next Generation Surgical Aortic Valve trial was a prospective, multicenter, single-arm study, with successful implants in 287 patients with aortic valve stenosis who underwent rapid deployment aortic valve replacement using the EDWARDS INTUITY Valve System (Edwards Lifesciences, Irvine, Calif). Patients were evaluated perioperatively for procedural times and technical success rates; at discharge, for hospital length of stay; and, at 30 days, for early adverse events.

RESULTS

A total of 158 patients underwent isolated aortic valve replacement through a full sternotomy (n = 71), upper hemisternotomy (n = 77), or right anterior thoracotomy (n = 10). Mean age at baseline was 75.7 ± 7.2 years. Mean aortic crossclamp and cardiopulmonary bypass times (minutes) were similar for full sternotomy and upper hemisternotomy, 43.5 ± 32.5/71.6 ± 41.8 and 43.1 ± 13.1/69.6 ± 19.1, respectively, and significantly longer for right anterior thoracotomy, 88.3 ± 18.6/122.2 ± 22.1 (P < .000). Early adverse event rates were similar, and in-hospital mortality rates were low regardless of surgical approach.

CONCLUSIONS

These data suggest that isolated rapid deployment aortic valve replacement through an upper hemisternotomy can lead to shorter crossclamp times than has been reported historically in the literature. This may facilitate minimal access aortic valve replacement by eliminating the issue of prolonged crossclamp times. Further, low in-hospital mortality and new permanent pacemaker implant rates were observed regardless of surgical approach.

Minimally invasive aortic valve surgery: Cleveland Clinic experience

BACKGROUND

Minimally invasive surgery has become a routine approach for aortic valve disease over the last 18 years at the Cleveland Clinic. It is performed in isolation or in combination with other procedures. The objective of this study is to review trends and outcomes in these patients.

METHODS

Cleveland Clinic Cardiovascular Information Registry (CVIR) was searched for aortic valve procedures from 1996 to 2013. All patients undergoing isolated or combined aortic valve operations were included for analysis. The incision type and procedure type were reviewed and trends were evaluated over time. Cleveland Clinic outcomes with minimally invasive approaches to the aortic valve are reviewed.

RESULTS

A total of 22,766 aortic valve surgical procedures were performed in this 18-year timeframe. Of these, 3,385 (14.9%) were minimally invasive procedures (MIPs) and 2,379 (10.5%) were isolated minimally invasive aortic valves. MIPs increased from 12.4% to 29.6% of the total aortic valve volume over the period of the study. Combined procedures, including concomitant surgery on the aorta, mitral valve, tricuspid valve, and arrhythmia surgery increased over time as well. Overall mortality for primary and reoperative aortic valve operations continues to decline and has consistently been less than 1% for several years.

CONCLUSIONS

A programmed approach to minimally invasive aortic valve surgery (MIAVS) with careful patient selection, appropriate use of preoperative imaging, and selective conversion to sternotomy when necessary, allows for aortic valve replacement (AVR) and a wide range of concomitant procedures to be performed safely in a large number of patients.