Successful Use of Sternal-Sparing Minimally Invasive Surgery for Proximal Ascending Aortic Pathology

Minimally Invasive Approach for Replacement of the Ascending Aorta towards the Proximal Aortic Arch

Objectives: In recent years, minimally invasive approaches have been used with increasing frequency, even for more complex aortic procedures. However, evidence on the practicability and safety of expanding minimally invasive techniques from isolated operations of the ascending aorta towards more complex operations such as the hemiarch replacement is still scarce to date. Methods: A total of 86 patients undergoing elective surgical replacement of the ascending aorta with (n = 40) or without (n = 46) concomitant proximal aortic arch replacement between 2009 and 2023 were analyzed in a retrospective single-center analysis. Groups were compared regarding operation times, intra- and postoperative complications and long-term survival. Results: Operation times and ventilation times were significantly longer in the hemiarch replacement group. Despite this, no statistically significant differences between the two groups were observed for the duration of the ICU and hospital stay and postoperative complication rates. At ten-year follow-up, overall survival was 82.6% after isolated ascending aorta replacement and 86.3% after hemiarch replacement (p = 0.441). Conclusions: Expanding the indication for minimally invasive aortic surgery towards the proximal aortic arch resulted in comparable postoperative complication rates, length of hospital stay and overall long-term survival compared to the well-established minimally invasive isolated supracommissural ascending aorta replacement.

Surgery of the ascending aorta via a right anterior minithoracotomy: initial surgical experience of a single center

OBJECTIVES

Full median sternotomy (FMS) is the common surgical access for patients undergoing replacement of the ascending aorta (AA) with or without aortic valve replacement (AVR). The right anterior mini-thoracotomy (RAMT) approach has been increasingly adopted for AVR. This approach has been shown to decrease blood loss and hospital length of stay (LOS) compared with FMS. The RAMT approach may also be beneficial in selected patients requiring AA procedures with or without AVR. We present our initial clinical experience of patients who have undergone a RAMT for supracommissural replacement of the tubular AA with or without AVR.

METHODS

This is a single-center retrospective review of 10 patients who underwent an elective RAMT for replacement of the tubular AA with or without AVR between November 2019 and January 2022. Clinical outcomes evaluated include 30-day mortality, intensive care and hospital LOS, time to extubation, operative times, as well as postoperative complications such as stroke and bleeding.

RESULTS

Median cross-clamp and cardiopulmonary bypass times were 109 and 148 min, respectively. Median time to extubation was 2.5 h and median intensive care unit and hospital stay were 2 and 10 days, respectively. There were two re-thoracotomies for postoperative bleeding and two cases of sub-xiphoidal pericardial drainage for pericardial effusion. There were no strokes and no in-hospital nor 30-day mortalities.

CONCLUSIONS

The replacement of the AA with or without concomitant AVR can be performed through a RAMT in carefully selected patients. However, the safety of this approach, as compared to full/partial median sternotomy, remains to be proven.

External validation of a predictive model for reintubation after cardiac surgery: A retrospective, observational study

STUDY OBJECTIVE

Explore validation of a model to predict patients' risk of failing extubation, to help providers make informed, data-driven decisions regarding the optimal timing of extubation.

DESIGN

We performed temporal, geographic, and domain validations of a model for the risk of reintubation after cardiac surgery by assessing its performance on data sets from three academic medical centers, with temporal validation using data from the institution where the model was developed.

SETTING

Three academic medical centers in the United States.

PATIENTS

Adult patients arriving in the cardiac intensive care unit with an endotracheal tube in place after cardiac surgery.

INTERVENTIONS

Receiver operating characteristic (ROC) curves and concordance statistics were used as measures of discriminative ability, and calibration curves and Brier scores were used to assess the model's predictive ability.

MEASUREMENTS

Temporal validation was performed in 1642 patients with a reintubation rate of 4.8%, with the model demonstrating strong discrimination (optimism-corrected c-statistic 0.77) and low predictive error (Brier score 0.044) but poor model precision and recall (Optimal F1 score 0.29). Combined domain and geographic validation were performed in 2041 patients with a reintubation rate of 1.5%. The model displayed solid discriminative ability (optimism-corrected c-statistic = 0.73) and low predictive error (Brier score = 0.0149) but low precision and recall (Optimal F1 score = 0.13). Geographic validation was performed in 2489 patients with a reintubation rate of 1.6%, with the model displaying good discrimination (optimism-corrected c-statistic = 0.71) and predictive error (Brier score = 0.0152) but poor precision and recall (Optimal F1 score = 0.13).

MAIN RESULTS

The reintubation model displayed strong discriminative ability and low predictive error within each validation cohort.

CONCLUSIONS

Future work is needed to explore how to optimize models before local implementation.

Expanding the Minimally Invasive Approach towards the Ascending Aorta-A Practical Overview of the Currently Available Techniques

Minimally invasive techniques have gained immense importance in cardiovascular surgery. While minimal access strategies for coronary and mitral valve surgery are already widely accepted and often used as standard approaches, the application of minimally invasive techniques is currently expanded towards more complex operations of the ascending aorta as well. In this new and developing field, various techniques have been established and reported ranging from upper hemisternotomy approaches, which allow even extensive operations of the ascending aorta to be performed through a minimally invasive access to sternal sparing thoracotomy strategies, which completely avoid sternal trauma during ascending aorta replacements. All of these techniques place high demands on patient selection, preoperative planning, and practical surgical implementation. Application of these strategies is currently limited to high-volume centers and highly experienced surgeons. This narrative review gives an overview of the currently available techniques with a special focus on the practical execution as well as the advantages and disadvantages of the currently available techniques. The first results demonstrate the practicability and safety of minimally invasive techniques for replacement of the ascending aorta in a well-selected patient population. With success and complication rates comparable to classic full sternotomy, the proof of concept for minimally invasive replacement of the ascending aorta is now achieved.

Comparison of minimally invasive versus conventional thoracic aortic operations: Early and midterm results in a series of 624 patients

OBJECTIVE

Despite minimally invasive techniques having gained wider application in cardiac surgery, current evidence on minithoracic aortic surgery is still limited. The aim of this study was to compare early and midterm outcomes of patients undergoing operations of the proximal thoracic aorta through ministernotomy (MS) versus full sternotomy (FS).

METHODS

Data from 624 consecutive patients who underwent proximal aortic repair through MS (n = 214, 34.3%) and FS (n = 410, 65.7%) at two aortic centers were analyzed. Treatment selection bias was addressed using propensity score matching (MS vs. FS). After matching, two well-balanced groups of 202 patients each were created.

RESULTS

Median cardiopulmonary bypass and cross-clamp times were 88 and 68 min, respectively, with no difference between groups. Overall, 30-day mortality was 1% (n = 2) in MS and 0.5% (n = 1) in FS (p = .6). No difference was found in the rates of stroke (MS n = 5, 2.5%; FS n = 5, 2.5%), dialysis (MS n = 1, 0.5%; FS n = 4, 2%), bleeding (MS n = 7, 3.5%; FS n = 7, 3.5%), and blood transfusions (MS n = 67, 33.3%; FS n = 57, 28.4%). Patients receiving MS showed a lower incidence of respiratory insufficiency compared with FS (0% vs. 2.5%, p = .04). Intensive care unit and hospital stays were similar between groups. Two-year survival rate was 97.2% in MS and 96.5% in FS (p = .9).

CONCLUSIONS

Mini proximal aortic operations can be performed successfully without compromising the proven efficacy and safety of conventional access. In selected patients, MS was associated with very low mortality and morbidity rates. Additionally, MS demonstrated superior clinical outcomes as regards respiratory adverse events, when compared with FS.

Right-parasternal approach for aortic valve replacement and ascending aortic repair after ante-thoracic route gastric tube reconstruction

Due to the limitations of surgical incisions and approaches brought on by the presence of gastric tube (GT), open heart surgery following ante-thoracic route GT reconstruction remains challenging. A-73-year-old man, who had a history of esophageal resection and ante-thoracic route GT reconstruction required aortic valve replacement (AVR) concomitant with ascending aortic repair (AAR) for aortic stenosis and dilated ascending aorta. We performed open heart surgery via a right-parasternal approach to avoid injury to the GT and nutrient arteries. This approach provided a good operative field, similar to median sternotomy. To our knowledge, this is the first case of AVR concomitant with AAR after ante-thoracic route GT reconstruction via a right-parasternal approach. We consider that the right-parasternal approach is reasonable for patients with ante-thoracic route GT reconstruction.

Aortic valve replacement via right anterolateral minithoracotomy: preventing adverse events during the initial learning curve

BACKGROUND

Despite excellent outcomes and reduced invasiveness, the right anterolateral thoracotomy approach for aortic valve replacement (RALT-AVR) has not been broadly adopted. This study provides results regarding the initial experience and learning curve of a single surgeon performing this procedure.

METHODS

Periprocedural details and postoperative outcomes of the first 100 consecutive patients who underwent RALT-AVR at our institution were retrospectively analyzed. We conducted a cumulative sum analysis of surgical failure, defined as occurrence of 30-day-mortality, surgical revision for bleeding, conversion to sternotomy, 3^rd degree heart block, paravalvular leakage, postoperative stroke or mean transvalvular gradient >20 mmHg.

RESULTS

The cohort was of low surgical risk (mean EuroSCORE II 1.31%±0.85, mean STS PROM 1.45%±0.97), 58% were males. Median cross-clamp time was 67.5 (57.8-76) min, median CPB time 105 (91.8-119) min, and median operation time 164.5 (144.5-183.2) min. There were no conversions to full sternotomy, 4 cases of revision for bleeding and 2 pacemaker implantations for 3^rd degree heart block. Prosthesis function was good (median ΔPmean 10.9 [7.4-13.6] mmHg). Thirty-day-mortality was 0%. The log-likelihood graph never crossed the upper boundary, and after a steady decrease, crossed the lower boundary at 93 patients.

CONCLUSIONS

RALT-AVR can be performed with acceptable procedural times and satisfactory outcomes. For a well-trained surgeon, adapting to this new procedure does not expose patients to an increased risk, when patient selection and procedural planning are applied appropriately. Cumulative sum failure analysis is an appropriate tool to monitor the transition from standard AVR to the technically more demanding RALT-AVR.

Minimally invasive approach: is this the future of aortic surgery?

Median sternotomy incision has shown to be a safe and efficacious approach in patients who require thoracic aortic interventions and still represents the gold-standard access. Nevertheless, over the last decade, less invasive techniques have gained wider clinical application in cardiac surgery becoming the first-choice approach to treat heart valve diseases, in experienced centers. The popularization of less invasive techniques coupled with an increased patient demand for less invasive therapies has motivated aortic surgeons to apply minimally invasive approaches to more challenging procedures, such as aortic root replacement and arch repair. However, technical demands and the paucity of available clinical data have still limited the widespread adoption of minimally invasive thoracic aortic interventions. This review aimed to assess and comment on the surgical techniques and the current evidence on mini thoracic aortic surgery.

Minimally invasive versus conventional surgery of the ascending aorta and root: a systematic review and meta-analysis

Limited uptake of minimally invasive surgery (MIS) of the aorta hinders assessment of its efficacy compared to median sternotomy (MS). The objective of this systematic review is to compare operative and perioperative outcomes for MIS versus MS. Online databases Medline, EMBASE, Cochrane Library and Web of Science were searched from inception until July 2018. Both randomized and observational studies of patients undergoing aortic root, ascending aorta or aortic arch surgery by MIS versus MS were eligible for inclusion. Primary outcomes were 30-day mortality, reoperation for bleeding, perioperative renal impairment and neurological events. Intraoperative and postoperative timing measures were also evaluated. Thirteen observational studies were included comparing 1101 MIS and 1405 MS patients. The overall quality of evidence was very low for all outcomes. Mortality and the incidence of stroke were similar between the 2 cohorts. Meta-analysis demonstrated increased length of cardiopulmonary bypass (CPB) time for patients undergoing MS [standardized mean difference 0.36, 95% confidence interval (CI) 0.15-0.58; P = 0.001]. Patients receiving MS spent more time in hospital (standardized mean difference 0.30, 95% CI 0.17-0.43; P < 0.001) and intensive care (standardized mean difference 0.17, 95% CI 0.06-0.27; P < 0.001). Reoperation for bleeding (risk ratio 1.51, 95% CI 1.06-2.17; P = 0.024) and renal impairment (risk ratio 1.97, 95% CI 1.12-3.46; P = 0.019) were also greater for MS patients. There was substantial heterogeneity in meta-analyses for CPB and aortic cross-clamp timing outcomes. MIS may be associated with improved early clinical outcomes compared to MS, but the quality of the evidence is very low. Randomized evidence is needed to confirm these findings.

Midterm results of less invasive approach to ascending aorta and aortic root surgery

Background

Minimally invasive aortic valve (AV) surgery has become widely accepted alternative to standard sternotomy. Despite possible reduction in morbidity, this approach is not routinely performed for aortic surgery. Current report aimed to demonstrate early and mid-term outcomes in patients undergoing minimally invasive aortic root- and ascending aorta-replacement with or without concomitant AV replacement (AVR).

Methods

Between 2011 and 2018, 167 selected low- and intermediate risk patients (mean age: 64.1±11.3; 70% men; EuroSCORE II 2.58±3.26) underwent minimally invasive aortic surgery. The “V” shaped partial upper sternotomy was performed through a 6-cm skin incision. Patients were divided into minimally invasive root reimplantation/replacement/remodelling (root RRR), supracoronary aorta replacements (SCAR) and SCAR+AVR. Kaplan-Meier estimates of survival were used.

Results

Mean follow-up was 3.1 year (max 7.7 years). Of 167 patients, 82 (49%) underwent SCAR; 44 (26%) SCAR + AVR. Forty-one patients (25%) underwent minimally invasive root RRR. Average aortic diameter was 6.00±0.46 cm. The cardiopulmonary bypass and aortic cross-clamp time were 152.0±46.8 and 101.8±36.8 minutes. There was one conversion to sternotomy. Median intensive care unit stay was 2.0 (IQR: 1.0–3.0) days. Thirty-day mortality was 1%. Within investigated follow-up, there was one late reoperation due to aortic valve thrombosis; late survival was estimated at 95% without differences between types of surgery: hazard ratio, 0.81; 95% CI: 0.36–1.81; P=0.61.

Conclusions

Minimally invasive aortic surgery performed through “V” shaped partial upper sternotomy is feasible and safe in selected patients regardless of the extent of repair, from supracoronary aorta replacements to complex root surgery.

Review of cerebral perfusion strategies for aortic surgery with application for minimally invasive approaches

Aortic arch and hemiarch surgery necessitate the temporary interruption of blood perfusion to the brain. Despite its complexity, hemiarch and ascending aortic surgery can be performed via a minimally invasive approach. Due to the higher risk of neurological injury during a circulatory arrest, several techniques were developed to further protect the brain during this surgery. We searched the Embase, Medline, and Cochrane databases and identified articles reporting outcomes of antegrade and retrograde cerebral perfusion strategies. Herein, we outline surgical approaches, intra-operative technical considerations, and clinical outcomes of hemiarch and ascending aortic surgery. Hemiarch and ascending aortic surgery is associated with a higher risk of mortality and morbidity. Attention to the optimal approach and cerebral protection strategy has been shown to significantly affect outcomes and mitigate risk.

Right Anterior Mini-Thoracotomy for Discrete Fibromembranous Subaortic Stenosis

Discrete fibromembranous subaortic stenosis is a common type of subaortic stenosis causing clinically significant left ventricular outflow obstruction. Surgery for discrete subaortic stenosis is most often performed through a typical midline sternotomy. Herein, we present our experience with an adult patient who underwent a right mini-thoracotomy for subaortic membrane resection with central cannulation under direct operative vision.

Surgical management of the aorta in BAV patients

Patients with a bicuspid aortic valve (BAV) frequently develop aneurysms of the aortic root and tubular ascending aorta. Aneurysms of the aortic arch, in the absence of concomitant aortopathies, are much less common. According to the 2018 American Association of Thoracic Surgery consensus guidelines on BAV-related aortopathy, prophylactic surgical aortic repair / replacement is recommended starting at a maximum aortic diameter of 50 mm in patients with risk factors. Concomitant aortic surgery is also recommended at an aortic diameter of 45 mm in those patients with other indications for cardiac surgery (most commonly aortic valve procedures). The ultimate goal of prophylactic aortic surgery is the prevention of aortic catastrophes, e.g. aortic rupture or acute aortic dissection, which are associated with high morbidity and mortality. The surgical technique used - in elective and emergency cases - depends on the involvement and nature of the aortic valve disease, as well as the extent of aortic aneurysm formation. The current review focusses on the surgical management of the aortic root, tubular ascending aorta, and proximal aortic arch in BAV patients. Despite the abovementioned recommendations, many BAV patients develop acute aortic syndromes below the recommended aortic diameter thresholds. Further research is therefore required in order to identify high-risk BAV subgroups that would benefit from earlier surgical repair.

Right Mini-Thoracotomy Subaortic Membrane Resection

OBJECTIVE

Subaortic membrane is an anatomical intracardiac anomaly that may cause discrete subaortic stenosis and aortic insufficiency. Patients requiring subaortic membrane resection may benefit from a minimally invasive approach; however, subaortic membranes are typically resected through a median sternotomy. We present our initial clinical experience of adult patients who have undergone a mini-thoracotomy subaortic membrane resection.

METHODS

Eight patients who underwent an elective subaortic membrane resection performed through a mini-thoracotomy were retrospectively reviewed. A 5-cm mini-thoracotomy incision was made in the 2nd intercostal space; a videoscope was inserted through a separate incision within the same interspace. Cardiopulmonary bypass (CPB) was instituted via central arterial and peripheral venous cannulation and an aortotomy was made. The subaortic membrane was resected with shafted instruments. The left ventricular outflow tract was inspected and CPB was weaned. Thirty-day mortality, intensive care and hospital length of stay, ventilation time, operative times, postoperative morbidity, and need for additional procedures were evaluated.

RESULTS

The median CPB and cross-clamp times were 60 and 42 minutes, respectively. The median time to extubation was 3.6 hours. The median intensive care unit and hospital stay were 22 hours and 3 days, respectively. The postoperative left ventricular outflow tract mean gradients decreased significantly (26.5 vs. 9.4 mm Hg, P = 0.001). There were no conversions to sternotomy, perioperative strokes, or 30-day mortality.

CONCLUSIONS

Subaortic membranes can be resected through a mini-thoracotomy approach with excellent clinical results.

Titanium Fastener Utilization During HeartMate 3 Left Ventricular Assist Device Implantation

OBJECTIVE

The objective of this study was to investigate the feasibility of using titanium fasteners for securement of the inflow sewing ring during HeartMate 3 implantation. The secondary objective was to compare cardiopulmonary bypass and total operative times between the titanium fastener and hand-tied knot groups.

METHODS

Clearance between the sewing ring and the HeartMate 3 device was assessed in vitro. Thirty-one patients undergoing HeartMate 3 implantation via median sternotomy at a single center from April 2017 to February 2018 were reviewed. The sewing ring was secured with hand-tied knots (n = 18) or titanium fasteners (n = 13). Cannulation strategy and implantation technique were otherwise identical between groups. Central arterial and venous cannulation was performed for cardiopulmonary bypass. The left ventricular apex was cored, and the sewing ring was attached with hand-tied knots or titanium fasteners.

RESULTS

There was adequate clearance for the titanium fastener to secure the inflow sewing ring and then connect to the HeartMate 3 in vitro. The inflow sewing ring was successfully secured during HeartMate 3 implantation in the titanium fastener group. Cardiopulmonary bypass time was 75 and 92 minutes for the titanium fastener and hand-tied groups, respectively (P < 0.03). Total operative time was 177 and 193 minutes for the titanium fastener and hand-tied groups, respectively (P = 0.513).

CONCLUSIONS

The inflow sewing ring of the HeartMate 3 was efficiently secured using titanium fasteners. Titanium fasteners resulted in shorter cardiopulmonary bypass times compared with the hand-tied group. There was no difference in total operative time.

Right Mini-thoracotomy Bentall Procedure

Objective

Bentall procedures are traditionally performed through a median sternotomy. The right mini-thoracotomy approach is increasingly used in aortic valve replacement. This approach has been shown to have decreased blood loss and hospital length of stay compared with sternotomy. A right mini-thoracotomy approach may also be beneficial in selected patients requiring aortic root surgery. We present our initial clinical experience of patients who have undergone a right mini-thoracotomy Bentall.

Methods

This is a single-center retrospective review of seven patients who underwent a primary elective right anterior mini-thoracotomy Bentall. A thoracoscope was used in each case. Automated suturing technology was used for annular suturing in three of the seven patients. Clinical outcomes evaluated include 30-day mortality, intensive care and hospital length of stay, time to extubation, operative times, as well as postoperative sequelae including stroke, infection, and bleeding.

Results

Median cardiopulmonary bypass, cross-clamp, and circulatory arrest time were 217, 153, and 28 minutes, respectively. Median time to extubation was 10 hours and median intensive care unit and hospital stay was 1 and 4 days, respectively. One patient had a wound infection and one returned to the operating room for bleeding. There were no in-hospital or 30-day mortalities.

Conclusions

The Bentall procedure can be performed through a right anterior mini-thoracotomy in selected patients with excellent clinical results.