Neochordal Goldilocks: Analyzing the biomechanics of neochord length on papillary muscle forces suggests higher tolerance to shorter neochordae

OBJECTIVE

Estimating neochord lengths during mitral valve repair is challenging, because approximation must be performed largely based on intuition and surgical experience. Little data exist on quantifying the effects of neochord length misestimation. We aimed to evaluate the impact of neochord length on papillary muscle forces and mitral valve hemodynamics, which is especially pertinent because increased forces have been linked to aberrant mitral valve biomechanics.

METHODS

Porcine mitral valves (n = 8) were mounted in an ex vivo heart simulator, and papillary muscles were fixed to high-resolution strain gauges while hemodynamic data were recorded. We used an adjustable system to modulate neochord lengths. Optimal length was qualitatively verified by a single experienced operator, and neochordae were randomly lengthened or shortened in 1-mm increments up to ±5 mm from the optimal length.

RESULTS

Optimal length neochordae resulted in the lowest peak composite papillary muscle forces (6.94 ± 0.29 N), significantly different from all lengths greater than ±1 mm. Both longer and shorter neochordae increased forces linearly according to difference from optimal length. Both peak papillary muscle forces and mitral regurgitation scaled more aggressively for longer versus shorter neochordae by factors of 1.6 and 6.9, respectively.

CONCLUSIONS

Leveraging precision ex vivo heart simulation, we found that millimeter-level neochord length differences can result in significant differences in papillary muscle forces and mitral regurgitation, thereby altering valvular biomechanics. Differences in lengthened versus shortened neochordae scaling of forces and mitral regurgitation may indicate different levels of biomechanical tolerance toward longer and shorter neochordae. Our findings highlight the need for more thorough biomechanical understanding of neochordal mitral valve repair.

Left ventricular fibrosis and CMR tissue characterization of papillary muscles in mitral valve prolapse patients

PURPOSE

Mitral valve prolapse (MVP) is associated with left ventricle (LV) fibrosis, including the papillary muscles (PM), which is in turn linked to malignant arrhythmias. This study aims to evaluate comprehensive tissue characterization of the PM by cardiovascular magnetic resonance (CMR) imaging and its association with LV fibrosis observed by intraoperative biopsies.

METHODS

MVP patients with indication for surgery due to severe mitral regurgitation (n = 19) underwent a preoperative CMR with characterization of the PM: dark-appearance on cine, T1 mapping, conventional bright blood (BB) and dark blood (DB) late gadolinium enhancement (LGE). CMR T1 mapping was performed on 21 healthy volunteers as controls. LV inferobasal myocardial biopsies were obtained in MVP patients and compared to CMR findings.

RESULTS

MVP patients (54 ± 10 years old, 14 male) had a dark-appearance of the PM with higher native T1 and extracellular volume (ECV) values compared with healthy volunteers (1096 ± 78ms vs. 994 ± 54ms and 33.9 ± 5.6% vs. 25.9 ± 3.1%, respectively, p < 0.001). Seventeen MVP patients (89.5%) had fibrosis by biopsy. BB-LGE + in LV and PM was identified in 5 (26.3%) patients, while DB-LGE + was observed in LV in 9 (47.4%) and in PM in 15 (78.9%) patients. DB-LGE + in PM was the only technique that showed no difference with detection of LV fibrosis by biopsy. Posteromedial PM was more frequently affected than the anterolateral (73.7% vs. 36.8%, p = 0.039) and correlated with biopsy-proven LV fibrosis (Rho 0.529, p = 0.029).

CONCLUSIONS

CMR imaging in MVP patients referred for surgery shows a dark-appearance of the PM with higher T1 and ECV values compared with healthy volunteers. The presence of a positive DB-LGE at the posteromedial PM by CMR may serve as a better predictor of biopsy-proven LV inferobasal fibrosis than conventional CMR techniques.

Sex-Related Differences After Proximal Aortic Surgery: Outcome Analysis of 1773 Consecutive Patients

BACKGROUND

Guidelines on the management of aortic aneurysm disease do not account for sex differences regarding surgical procedures on the proximal aorta, although faster aneurysm growth, increased rupture risk, and higher postoperative mortality have been found in women. We therefore analyzed outcome differences between men and women receiving operations on the proximal aorta.

METHODS

A total of 1773 patients underwent nonemergency surgical procedures on the aortic valve (AV) and proximal aorta at our institution between 2000 and 2018. Of these, 772 patients (21.8% women) received a Bentall procedure, 349 (20.3% women) had AV-sparing root replacement, and 652 (31.1% women) underwent AV and supracommissural ascending aorta replacement. Primary outcomes were in-hospital mortality and midterm survival.

RESULTS

When assessing sex-related differences within the entire group of patients that received an operation on the proximal aorta, women were found to be older, had a lower body mass index, and were smokers less often. Despite shorter procedural times, median ventilation times and intensive care unit length of stay were longer in women. In-house mortality was also higher in women (3.6% vs 0.9%, P < .001). Multivariable logistic regression revealed age (odds ratio [OR], 1.8; 95% CI, 1.4-2.3 per 5 years added; P < .001), female sex (OR, 2.6; 95% CI, 1.2-5.8; P = .02), and urgent surgery (OR, 3.1; 95% CI, 1.2-7.3; P = .01) as independent risk factors for in-house death. Midterm survival was lower for women in the entire cohort (P = .02) and particularly within the Bentall subgroup (P = .004).

CONCLUSIONS

Female sex is an independent risk factor for operative mortality in patients undergoing proximal aortic surgery but is currently not addressed in guidelines. More research should focus on etiology and prevention of these worse outcomes in female patients.

The Feasibility of Less-Invasive Bentall Surgery: A Real-World Analysis

OBJECTIVE

Minimally invasive approaches are being used increasingly in cardiac surgery and applied in a wider range of operations, including complex aortic procedures. The aim of this study was to examine the safety and feasibility of a partial upper sternotomy approach for isolated elective aortic root replacement (a modified Bentall procedure).

METHODS

We performed a retrospective analysis of 768 consecutive patients who had undergone isolated Bentall surgery between January 2000 and January 2021 at our institution, with the exclusion of re-operations, endocarditis, acute aortic dissections, and root replacement with major concomitant procedures such as multi-valve or coronary bypass surgery. A total of 98 patients were operated on via partial sternotomy (PS) and were matched 2:1 to 196 patients operated on via full sternotomy (FS).

RESULTS

The procedure time was 12 min longer in the PS group (205 min vs. 192.5 min in the FS group, p = 0.002), however, cardiopulmonary bypass and aortic cross-clamp times were comparable between groups. Eight PS-procedures were converted to full sternotomy, predominantly for bleeding complications (n = 6). Re-exploration for acute bleeding was necessary in 11% of the PS group and 4.1% of the FS group (p = 0.02). Five FS patients and none in the PS group required emergency coronary bypass grafting for postoperative coronary obstruction (p = 0.2). PS patients were hospitalized for a significantly shorter period (9.5 days vs. 10.5 days in the FS group, respectively). There were no significant differences regarding in-hospital (p = 0.4) and mid-term mortality (p = 0.73), as well as for other perioperative complications.

CONCLUSIONS

Performing Bentall operations via partial upper sternotomy is associated with similar perfusion and cross-clamp times, as well as overall mortality, when compared to a full sternotomy approach. A low threshold for conversion to full sternotomy should be accepted if limited access proves insufficient for the handling of intraoperative complications, particularly bleeding.

Utilization of Engineering Advances for Detailed Biomechanical Characterization of the Mitral-Ventricular Relationship to Optimize Repair Strategies: A Comprehensive Review

The geometrical details and biomechanical relationships of the mitral valve-left ventricular apparatus are very complex and have posed as an area of research interest for decades. These characteristics play a major role in identifying and perfecting the optimal approaches to treat diseases of this system when the restoration of biomechanical and mechano-biological conditions becomes the main target. Over the years, engineering approaches have helped to revolutionize the field in this regard. Furthermore, advanced modelling modalities have contributed greatly to the development of novel devices and less invasive strategies. This article provides an overview and narrative of the evolution of mitral valve therapy with special focus on two diseases frequently encountered by cardiac surgeons and interventional cardiologists: ischemic and degenerative mitral regurgitation.

Atrial Dysfunction in Significant Atrial Functional Mitral Regurgitation: Phenotypes and Prognostic Implications

BACKGROUND

Atrial functional mitral regurgitation (AFMR) is associated with increased morbidity and mortality. Left atrial (LA) size and function in AFMR are poorly characterized. We aimed to assess LA function by reservoir strain (LASr) and estimated reservoir work (LAWr) and their impact on outcome in AFMR.

METHODS

Consecutive patients at our institution between 2001 and 2019 and with significant (moderate or greater) AFMR were examined. LAWr was estimated as LASr×LA reservoir volume, and patients were grouped by median LASr and LAWr. Outcomes were all-cause death or heart failure hospitalizations.

RESULTS

Five hundred fifteen AFMR patients were followed up for 5 (1-17) years. Patients had previously documented atrial fibrillation (AF; 37%), heart failure with preserved ejection fraction (HFpEF) without AF (24%), or both (HFpEF+AF, 39%). LA volume was largest in AF, while LA function parameters were most impaired in the combined HFpEF+AF group. During follow-up, patients with low LASr or LAWr had higher risk of death (P<0.001) and heart failure hospitalization (P<0.05). In Cox regression analyses, low LASr and LAWr, but not LA volume or left ventricular function, were associated with a higher risk of death (LASr: hazard ratio, 2.3 [95% CI, 1.6-3.5]; LAWr: hazard ratio, 3.4 [95% CI, 2.4-4.9]; both P<0.001) after adjustment for clinical and echocardiographic confounders. Low LASr and LAWr were strongest associated with death in HFpEF and HFpEF+AF.

CONCLUSIONS

LA reservoir function but not LA size is a robust predictor of outcome in significant AFMR. This provides mechanistic insights into the interplay of functional versus geometric LA changes in AFMR.

Abnormal Mechanics Relate to Myocardial Fibrosis and Ventricular Arrhythmias in Patients With Mitral Valve Prolapse

BACKGROUND

The relation between ventricular arrhythmia and fibrosis in mitral valve prolapse (MVP) is reported, but underlying valve-induced mechanisms remain unknown. We evaluated the association between abnormal MVP-related mechanics and myocardial fibrosis, and their association with arrhythmia.

METHODS

We studied 113 patients with MVP with both echocardiogram and gadolinium cardiac magnetic resonance imaging for myocardial fibrosis. Two-dimensional and speckle-tracking echocardiography evaluated mitral regurgitation, superior leaflet and papillary muscle displacement with associated exaggerated basal myocardial systolic curling, and myocardial longitudinal strain. Follow-up assessed arrhythmic events (nonsustained or sustained ventricular tachycardia or ventricular fibrillation).

RESULTS

Myocardial fibrosis was observed in 43 patients with MVP, predominantly in the basal-midventricular inferior-lateral wall and papillary muscles. Patients with MVP with fibrosis had greater mitral regurgitation, prolapse, and superior papillary muscle displacement with basal curling and more impaired inferior-posterior basal strain than those without fibrosis (P<0.001). An abnormal strain pattern with distinct peaks pre-end-systole and post-end-systole in inferior-lateral wall was frequent in patients with fibrosis (81 versus 26%, P<0.001) but absent in patients without MVP with basal inferior-lateral wall fibrosis (n=20). During median follow-up of 1008 days, 36 of 87 patients with MVP with >6-month follow-up developed ventricular arrhythmias associated (univariable) with fibrosis, greater prolapse, mitral annular disjunction, and double-peak strain. In multivariable analysis, double-peak strain showed incremental risk of arrhythmia over fibrosis.

CONCLUSIONS

Basal inferior-posterior myocardial fibrosis in MVP is associated with abnormal MVP-related myocardial mechanics, which are potentially associated with ventricular arrhythmia. These associations suggest pathophysiological links between MVP-related mechanical abnormalities and myocardial fibrosis, which also may relate to ventricular arrhythmia and offer potential imaging markers of increased arrhythmic risk.

Left Atrial Function and Not Volume Predicts Mid-to-Late Atrial Fibrillation after Mitral Valve Repair

OBJECTIVES

Patients undergoing surgical mitral valve repair for degenerative mitral regurgitation are at risk of even late postoperative atrial fibrillation (AF). Left atrial (LA) functionhas been shown superior to LA volume in evaluating risk of AF in diverse cardiac conditions. We therefore investigated the prognostic value of LA function and volume in predicting mid-to-late postoperative AF after mitral valve repair (>30 days postoperatively).

METHODS

We retrospectively identified all patients who underwent mitral valve repair for degenerative mitral regurgitation between 2012-2019 at our institution. Exclusion criteria were preoperative AF, concomitant procedures, re-operations, missing or insufficiently processable preoperative echocardiograms, and missing follow-up. LA function and volume measurements were conducted using speckle-tracking strain echocardiographic analysis. Postoperative LA function was measured in a subgroup with sufficient postoperative echocardiograms.

RESULTS

We included 251 patients, of which 39 (15.5%) experienced AF in the mid-to-late postoperative period. Reduced LA strain parameters and more than mild preoperative tricuspid regurgitation were independently associated with mid-to-late postoperative AF. LA volume index had no association with mid-to-late postoperative AF in univariable analysis and did not improve performance of multivariable models. Patients with mid-to-late AF exhibited diminished improvement in LA function after surgery.

CONCLUSION

In mitral valve repair patients, LA function (but not volume) showed independent predictive value for mid-to-late postoperative AF. Including left atrial function into surgical decision making and approach may identify patients who will benefit from earlier intervention with the aim to prevent irreversible left atrial damage with consequent risk of postoperative AF.

Histopathological insights into mitral valve prolapse-induced fibrosis

Mitral valve prolapse (MVP) is a cardiac valve disease that not only affects the mitral valve (MV), provoking mitral regurgitation, but also leads to maladaptive structural changes in the heart. Such structural changes include the formation of left ventricular (LV) regionalized fibrosis, especially affecting the papillary muscles and inferobasal LV wall. The occurrence of regional fibrosis in MVP patients is hypothesized to be a consequence of increased mechanical stress on the papillary muscles and surrounding myocardium during systole and altered mitral annular motion. These mechanisms appear to induce fibrosis in valve-linked regions, independent of volume-overload remodeling effects of mitral regurgitation. In clinical practice, quantification of myocardial fibrosis is performed with cardiovascular magnetic resonance (CMR) imaging, even though CMR has sensitivity limitations in detecting myocardial fibrosis, especially in detecting interstitial fibrosis. Regional LV fibrosis is clinically relevant because even in the absence of mitral regurgitation, it has been associated with ventricular arrhythmias and sudden cardiac death in MVP patients. Myocardial fibrosis may also be associated with LV dysfunction following MV surgery. The current article provides an overview of current histopathological studies investigating LV fibrosis and remodeling in MVP patients. In addition, we elucidate the ability of histopathological studies to quantify fibrotic remodeling in MVP and gain deeper understanding of the pathophysiological processes. Furthermore, molecular changes such as alterations in collagen expression in MVP patients are reviewed.

Is perioperative fast-track management the future of proximal aortic repair?

OBJECTIVES

The Bentall procedure is the gold standard for patients with combined aortic root dilation and valve dysfunction. Over the past decade, fast-track (FT) perioperative anaesthetic management protocols have progressively evolved. We reviewed our results for selected patients undergoing Bentall surgery under an FT protocol.

METHODS

We retrospectively analysed a consecutive cohort of patients who underwent elective Bentall procedures at our institution between 2000 and 2018. Complex aortic root repair (i.e. David and Ross procedure, redo surgery, major concomitant procedures, emergency repair for acute dissections) was excluded. Patients who underwent conventional perioperative treatment and those treated according to our institutional FT concept were compared following 1:1 propensity score matching.

RESULTS

Of 772 patients who fit the in- and exclusion criteria, 565 were treated conventionally post-surgery, while 207 were treated using the FT protocol. Propensity score matching resulted in 197 pairs, with no differences in baseline characteristics after matching. In-house mortality, 30-day mortality and overall all-cause long-term mortality were comparable between the FT and the conventionally treated cohort. Postoperative anaesthetic care unit/intensive care unit length-of-stay (6.2 vs 20.6 h, P = 0.03) and postoperative ventilation times (158.9 vs 465.5 min, P < 0.001) were significantly shorter in the FT cohort. There were no differences in rates of postoperative adverse events.

CONCLUSIONS

In centres with experienced anaesthesiologists, perioperative FT management is non-inferior to conventionally treated patients undergoing elective Bentall procedures without compromising patient safety.

Building a successful minimally invasive mitral valve repair program before introducing the robotic approach: The Massachusetts General Hospital experience

Background

Patients with mitral valve prolapse (MVP) requiring surgical repair (MVr) are increasingly operated using minimally invasive strategies. Skill acquisition may be facilitated by a dedicated MVr program. We present here our institutional experience in establishing minimally invasive MVr (starting in 2014), laying the foundation to introduce robotic MVr.

Methods

We reviewed all patients that had undergone MVr for MVP via sternotomy or mini-thoracotomy between January 2013 and December 2020 at our institution. In addition, all cases of robotic MVr between January 2021 and August 2022 were analyzed. Case complexity, repair techniques, and outcomes are presented for the conventional sternotomy, right mini-thoracotomy and robotic approaches. A subgroup analysis comparing only isolated MVr cases via sternotomy vs. right mini-thoracotomy was conducted using propensity score matching.

Results

Between 2013 and 2020, 799 patients were operated for native MVP at our institution, of which 761 (95.2%) received planned MVr (263 [34.6%] via mini-thoracotomy) and 38 (4.8%) received planned MV replacement. With increasing proportions of minimally invasive procedures (2014: 14.8%, 2020: 46.5%), we observed a continuous growth in overall institutional volume of MVP (n = 69 in 2013; n = 127 in 2020) and markedly improved institutional rates of successful MVr, with 95.4% in 2013 vs. 99.2% in 2020. Over this period, a higher complexity of cases were treated minimally-invasively and increased use of neochord implantation ± limited leaflet resection was observed. Patients operated minimally invasively had longer aortic cross-clamp times (94 vs. 88 min, p = 0.001) but shorter ventilation times (4.4 vs. 4.8 h, p = 0.002) and hospital stays (5 vs. 6 days, p < 0.001) than those operated via sternotomy, with no significant differences in other outcome variables. A total of 16 patients underwent robotically assisted MVr with successful repair in all cases.

Conclusion

A focused approach towards minimally invasive MVr has transformed the overall MVr strategy (incision; repair techniques) at our institution, leading to a growth in MVr volume and improved repair rates without significant complications. On this foundation, robotic MVr was first introduced at our institution in 2021 with excellent outcomes. This emphasizes the importance of building a competent team to perform these challenging operations, especially during the initial learning curve.

Microvascular assessment of fascio-cutaneous flaps by ultrasound: A large animal study

Objectives: Blood perfusion quality of a flap is the main prognostic factor for success. Microvascular evaluation remains mostly inaccessible. We aimed to evaluate the microflow imaging mode, MV-Flow, in assessing flap microvascularization in a pig model of the fascio-cutaneous flap. Methods: On five pigs, bilateral saphenous fascio-cutaneous flaps were procured on the superficial femoral vessels. A conventional ultrasound evaluation in pulsed Doppler and color Doppler was conducted on the ten flaps allowing for the calculation of the saphenous artery flow rate. The MV-Flow mode was then applied: for qualitative analysis, with identification of saphenous artery collaterals; then quantitative, with repeated measurements of the Vascularity Index (VI), percentage of pixels where flow is detected relative to the total ultrasound view area. The measurements were then repeated after increasing arterial flow by clamping the distal femoral artery. Results: The MV-Flow mode allowed a better follow-up of the saphenous artery's collaterals and detected microflows not seen with the color Doppler. The VI was correlated to the saphenous artery flow rate (Spearman rho of 0.64; p = 0.002) and allowed to monitor the flap perfusion variations. Conclusion: Ultrasound imaging of microvascularization by MV-Flow mode and its quantification by VI provides valuable information in evaluating the microvascularization of flaps.

Native and Post-Repair Residual Mitral Valve Prolapse Increases Forces Exerted on the Papillary Muscles: A Possible Mechanism for Localized Fibrosis?

BACKGROUND

Recent studies have linked mitral valve prolapse to localized myocardial fibrosis, ventricular arrhythmia, and even sudden cardiac death independent of mitral regurgitation or hemodynamic dysfunction. The primary mechanistic theory is rooted in increased papillary muscle traction and forces due to prolapse, yet no biomechanical evidence exists showing increased forces. Our objective was to evaluate the biomechanical relationship between prolapse and papillary muscle forces, leveraging advances in ex vivo modeling and technologies. We hypothesized that mitral valve prolapse with limited hemodynamic dysfunction leads to significantly higher papillary muscle forces, which could be a possible trigger for cellular and electrophysiological changes in the papillary muscles and adjacent myocardium.

METHODS

We developed an ex vivo papillary muscle force transduction and novel neochord length adjustment system capable of modeling targeted prolapse. Using 3 unique ovine models of mitral valve prolapse (bileaflet or posterior leaflet prolapse), we directly measured hemodynamics and forces, comparing physiologic and prolapsing valves.

RESULTS

We found that bileaflet prolapse significantly increases papillary muscle forces by 5% to 15% compared with an optimally coapting valve, which are correlated with statistically significant decreases in coaptation length. Moreover, we observed significant changes in the force profiles for prolapsing valves when compared with normal controls.

CONCLUSIONS

We discovered that bileaflet prolapse with the absence of hemodynamic dysfunction results in significantly elevated forces and altered dynamics on the papillary muscles. Our work suggests that the sole reduction of mitral regurgitation without addressing reduced coaptation lengths and thus increased leaflet surface area exposed to ventricular pressure gradients (ie, billowing leaflets) is insufficient for an optimal repair.

Aortic root replacement in bicuspid versus tricuspid aortic valve patients

Background

Concomitant replacement of the aortic root and aortic valve is a widely used treatment strategy in elective patients with aortic valve stenosis and root aneurysm. It is also a strategy frequently employed in patients with acute aortic dissection type A (AADA), involving the aortic root. Although more patients have undergone valve sparing procedures over the past decades, the classic ‘modified Bentall technique’ remains a valid option, particularly for patients with a bicuspid aortic valve (BAV). We aimed to compare the results of elective and emergency modified Bentall procedures in patients with bicuspid and tricuspid aortic valves (TAVs).

Methods

We retrospectively reviewed our database for patients undergoing either elective or emergency modified Bentall procedures between 2000 and 2018 and identified 827 elective cases (44% BAV) and 258 emergency cases (15% BAV). Analysis of intra- and postoperative outcomes and early mortality was performed. Due to inequality of the groups, a matching analysis was performed.

Results

We found BAV patients to be significantly younger (elective: 58±18 vs. 65±14, P<0.001; emergency: 49±17 vs. 62±19, P<0.001) and healthier at time of surgery. In the AADA cohort, malperfusion rate was not different between bicuspid and tricuspid patients, however bicuspid AADA patients presented more often with an entry in the aortic root. After matching, procedure times and early outcomes did not differ between the groups, except for significantly higher rates of respiratory failure in elective TAV patients (10% vs. 5%, P=0.033). The 30-day mortality was 2% in elective cases and 22% in emergency AADA surgery. A subgroup analysis of elective patients with aortic diameter <55 mm also showed excellent outcomes.

Conclusions

After adjustment for preoperative inequalities, no differences in early mortality and outcomes were found between bicuspid and tricuspid patients receiving elective or emergency modified Bentall surgery.

Supracommissural replacement of the ascending aorta and the aortic valve via partial versus full sternotomy-a propensity-matched comparison in a high-volume centre

OBJECTIVES

Full sternotomy (FS) is the common surgical access for patients undergoing open aortic valve replacement (AVR) with concomitant supracommissural replacement of the tubular ascending aorta. Since minimally invasive approaches are being used with increasing frequency in cardiac surgery, the aim of this study was to compare outcomes of patients undergoing AVR with supracommissural replacement of the tubular ascending aorta via FS versus partial upper sternotomy (PS).

METHODS

We included all patients who underwent elective AVR with concomitant supracommissural replacement of the tubular ascending aorta at our institution between 2000 and 2015. Exclusion criteria were emergency surgery, other major concomitant procedures and reoperations. After 2:1 propensity score matching, outcomes of patients with PS and FS were compared.

RESULTS

A total of 652 consecutive patients were included, 117 patients operated via PS and 234 patients operated via FS. Cardiopulmonary bypass time and aortic cross-clamp time of the PS and FS groups were 89 vs 92 min (P = 0.2) and 65 vs 70 min (P = 0.3), respectively. Postoperative morbidity was low and there were no significant differences in postoperative outcomes between patient groups. In-hospital mortality was 1.7% in the PS vs 0.4% in the FS group (P = 0.3). Kaplan-Meier analysis revealed no difference in mid-term survival (P = 0.3). Reoperation rates for valve or aortic complications were very low with no significant difference between groups.

CONCLUSIONS

In a high-volume centre with extensive experience in minimally invasive cardiac surgery, AVR with concomitant supracommissural replacement of the tubular ascending aorta via PS results in similar outcomes with regard to safety and longevity when compared to conventional FS.

Minimally Invasive Coronary Revascularisation Surgery: A Focused Review of the Available Literature

Minimally invasive coronary revascularisation was originally developed in the mid 1990s as minimally invasive direct coronary artery bypass (MIDCAB) grafting is a less invasive approach compared to conventional coronary artery bypass grafting (CABG) to address targets in the left anterior descending coronary artery (LAD). Since then, MIDCAB has evolved with the adoption of a robotic platform and the possibility to perform multivessel bypass procedures. Minimally invasive coronary revascularisation surgery also allows for a combination between the benefits of CABG and percutaneous coronary interventions for non-LAD lesions – a hybrid approach. Hybrid coronary revascularisation results in fewer blood transfusions, shorter hospital stay, decreased ventilation times and patients return to work sooner when compared to conventional CABG. This article reviews the available literature, describes standard approaches and considers topics, such as limited access procedures, indications and patient selection, diagnostics and imaging, techniques, anastomotic devices, hybrid coronary revascularisation and outcome analysis.

Minithoracotomy versus full sternotomy for isolated aortic valve replacement: Propensity matched data from two centers

BACKGROUND

Minimally invasive approaches to isolated aortic valve replacement (AVR) continue to gain popularity. This study compares outcomes of AVR through right anterolateral thoracotomy (RALT) to those of AVR through full median sternotomy (MS).

METHODS

Outcomes of two propensity-matched groups of 85 each, out of 250 patients that underwent isolated AVR through RALT or MS at our two institutions, were compared in a retrospective study.

RESULTS

Propensity score matching resulted in 85 matched pairs with balanced preoperative characteristics. Procedure times were significantly shorter in the RALT group (median difference: 13 min [-25 to -0.5]; p = .039), cardiopulmonary bypass times were longer (median difference: 17 min [10-23.5]; p = < .001) and ventilation times shorter (median difference: 259 min [-390 to -122.5]; p = < .001). There was no significant difference in aortic cross-clamp times (median difference: 1.5 min [-3.5 to 6.5]; p = .573). The RALT group had lower rates of perioperative platelet transfusions (odds ratio [OR] = 0.00 [0.00-0.59]; p = .0078) and postoperative pneumonia (OR = 0.10 [0.00-0.70]; p = .012), as well as shorter hospitalization times (median difference: 2.5 days [-4.5 to -1]; p = .005). There were no significant differences regarding paravalvular leakage (p = .25), postoperative stroke (p = 1), postoperative atrial fibrillation (p = .12) or 1-year-mortality (p = 1).

CONCLUSIONS

This study found RALT to be an equally safe approach to surgical AVR as MS. Furthermore, RALT showed advantages regarding important aspects of postoperative recovery, especially concerning pulmonary function.

Surgical treatment of outflow graft kinking complicated by external obstruction with a fibrin mass in a patient with LVAD

BACKGROUND

Outflow graft (OG) obstruction is a dangerous complication that may occur for various reasons after left ventricular assist device (LVAD) implantation.

CASE SUMMARY

We describe the case of a 51-year-old patient on LVAD support who developed significant OG kinking and external OG obstruction due to a fibrin mass causing severe stenosis. Both the OG kinking and external obstruction were eliminated via a left lateral thoracotomy.

Minimally invasive surgical aortic valve replacement: The RALT approach

Less-invasive techniques for cardiothoracic surgical procedures are designed to limit surgical trauma, but the technical requirements and preoperative planning are more demanding than those for conventional sternotomy. Patient selection, interdisciplinary collaboration, and surgical skills are key factors for procedural success. Aortic valve replacement is frequently performed through an upper hemisternotomy, but the right anterior minithoracotomy represents an even less traumatic, technical advancement. Preoperative assessment of the ascending aorta in relation to the sternum is mandatory to select patients and the intercostal access site. This description of the surgical technique focuses on the specific procedural details including the obligatory planning with computed tomography and our cannulation strategy. We also sought to define the anatomical ascending aorta-sternal relationship, as it is of utmost importance in preoperative computed tomographic planning.

Cognitive impairment after cytotoxic chemotherapy

Background

Neurotoxicity is a frequent side effect of cytotoxic chemotherapy and affects a large number of patients. Despite the high medical need, few research efforts have addressed the impact of cytotoxic agents on cognition (ie, postchemotherapy cognitive impairment; PCCI). One unsolved question is whether individual cytotoxic drugs have differential effects on cognition. We thus examine the current state of research regarding PCCI. Neurological symptoms after targeted therapies and immunotherapies are not part of this review.

Methods

A literature search was conducted in the PubMed database, and 1215 articles were reviewed for predefined inclusion and exclusion criteria. Thirty articles were included in the systematic review.

Results

Twenty-five of the included studies report significant cognitive impairment. Of these, 21 studies investigated patients with breast cancer. Patients mainly received combinations of 5-fluorouracil, epirubicin, cyclophosphamide, doxorubicin, and taxanes (FEC/FEC-T). Five studies found no significant cognitive impairment in chemotherapy patients. Of these, 2 studies investigated patients with colon cancer receiving 5-fluorouracil and oxaliplatin (FOLFOX). Independent risk factors for PCCI were patient age, mood alterations, cognitive reserve, and the presence of apolipoprotein E e4 alleles.

Conclusions

There is evidence that certain chemotherapy regimens cause PCCI more frequently than others as evidenced by 21 out of 23 studies in breast cancer patients (mainly FEC-T), whereas 2 out of 3 studies with colon cancer patients (FOLFOX) did not observe significant changes. Further studies are needed defining patient cohorts by treatment protocol in addition to cancer type to elucidate the effects of individual cytotoxic drugs on cognitive functions.