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.

Twenty-year outcomes of minimally invasive direct coronary artery bypass surgery: The Leipzig experience.

OBJECTIVE: Minimally invasive direct coronary artery bypass (MIDCAB) surgery involving left anterior descending coronary artery grafting with the left internal thoracic artery through a left anterior small thoracotomy is being routinely performed in some specified centers for patients with isolated complex left anterior descending coronary artery disease, but very few reports regarding long-term outcomes exist in literature. Our study was aimed at assessing and analyzing the early and long-term outcomes of a large cohort of patients who underwent MIDCAB procedures and identifying the effects of changing trends in patient characteristics on early mortality. METHODS: A total of 2667 patients, who underwent MIDCAB procedures between 1996 and 2018, were divided into 3 groups on the basis of the year of surgery: group A, 1996-2003 (n = 1333); group B, 2004-2010 (n = 627) and group C, 2011-2018 (n = 707). Groupwise characteristics and early postoperative outcomes were compared. Long-term survival for all patients was analyzed and predictors for late mortality were identified using Cox proportional hazards methods. RESULTS: The mean age was 64.5 ± 10.9 years and 691 (25.9%) patients were female. Group C patients (log EuroSCORE I = 4.9 ± 6.9) were older with more cardiac risk factors and comorbidities than groups A (log EuroSCORE I = 3.1 ± 4.5) and B (log EuroSCORE I = 3.5 ± 4.7). Overall and groupwise in-hospital mortality was 0.9%, 1.0%, 0.6%, and 1.0% (P = .7), respectively. Overall 10-, 15-, and 20-year survival estimates for all patients were 77.7 ± 0.9%, 66.1 ± 1.2%, and 55.6 ± 1.6%, respectively. CONCLUSIONS: MIDCAB can be safely performed with very good early and long-term outcomes. In-hospital mortality remained constant over the 22-year period of the study despite worsening demographic profile of patients.

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.

Iatrogenic Type A Aortic Dissection: Challenges and Frontiers-Contemporary Single Center Data and Clinical Perspective.

Iatrogenic aortic dissection (IAD) is a rare but devastating complication in cardiac surgery and related procedures. Due to its rarity, published data on emergency surgery following IAD are limited. Herein, we discuss IAD occurring intra- and postoperatively, including those occurring during transcatheter aortic valve replacement and cardiac catheterization, and present benchmark data from our consecutive, single-center experience. We demonstrate changes in patient characteristics, surgical approaches, and outcomes over a 23-year period.

Impact of distal aortic perfusion on 'segmental steal' depleting spinal cord blood flow-a quantitative experimental approach.

OBJECTIVES: Aortic steal is an underestimated risk factor for intraoperative spinal cord ischaemia. A negative effect on spinal cord perfusion in thoraco-abdominal aneurysm repair has been suspected if blood drains away from the cord initiated by a reversal of the arterial pressure gradient. The amount of blood and pressure loss via back-bleeding of segmental arteries and the impact of distal aortic perfusion (DaP) have not been analysed yet. The aim of our study was to quantify 'segmental steal' in vivo during simulated thoraco-abdominal aneurysm repair and to determine the impact of DaP on steal and spinal cord perfusion. METHODS: Ten juvenile pigs were put on cardiopulmonary bypass with DaP and visceral arteries were ligated. 'Segmental steal' was quantified by draining against gravity with/without DaP. Blood volume of 'segmental steal' was quantified and microspheres were injected for Post mortem spinal cord perfusion analysis. 'Segmental steal' was quantified with/without DaP-and with stopped DaP. RESULTS: Quantification revealed a significantly higher steal on cardiopulmonary bypass with DaP with a mean difference of 24(11) ml/min. In all spinal cord segments, blood flow was diminished during steal drainage on DaP, compared to 'no steal'. The least perfused region was the low thoracic to upper lumbar segment. CONCLUSIONS: 'Segmental steal' is a relevant threat to spinal cord perfusion-even with the utilization of DaP-diminishing spinal cord perfusion. The blood volume lost by back-bleeding of segmental arteries is not to be underestimated and occlusion of segmental arteries should be considered in thoraco-abdominal aneurysm repair.

Is implantable cardioverter defibrillator surgery in patients with an implanted left ventricular assist device safe under uninterrupted oral anticoagulation?

BACKGROUND: Implantable cardioverter-defibrillator (ICD) surgery in patients with implanted left ventricular assist devices (LVAD) is associated with an increased risk of bleeding complications because of the need to ensure that these patients are adequately anticoagulated. Our study aimed to evaluate the safety of our new strategy of uninterrupted oral anticoagulation compared to heparin-bridging during the surgical interval. METHODS: Between January 2009 and January 2020, 116 patients with LVAD underwent ICD surgery. Since January 2015, 60 patients were operated under continued sufficient oral anticoagulation with a vitamin k antagonist (VKA group). Fifty-six patients underwent a heparin-bridging regimen (heparin group). Demographics, perioperative data, complications, and mortality were analyzed. RESULTS: Bleeding complications attributable to the surgical intervention occurred more often (19.6% vs. 10.0%, p = 0.142) and at a higher rate of re-exploratory surgery (14.3% vs. 5.0%, p = 0.088) in the heparin group without reaching statistical significance. Moreover, the heparin group patients' postoperative total length of stay was 10 days longer (17.8 ± 23.8 days vs. 8.3 ± 9.5 days, p = 0.007). There were no procedure-related deaths, no thromboembolic events, and no LVAD-related thrombosis. CONCLUSION: Our strategy of uninterrupted oral anticoagulation is safe and results in a reduction by more than half the number of days in hospital without an increase in adverse events.

Ischemic Spinal Cord Injury-Experimental Evidence and Evolution of Protective Measures.

BACKGROUND: Paraplegia remains one of the most devastating complications of descending and thoracoabdominal aortic repair. The aim of this review is to outline the current state of art in the rapidly developing field of spinal cord injury research. METHODS: A review of PubMed and Web of Science databases was performed using the following terms and their combinations: spinal cord, injury, ischemia, ischemia-reperfusion, ischemic spinal cord injury, paraplegia, paraparesis. Articles published before July 2019 were screened and included if considered relevant. RESULTS: The review focuses on the topic of spinal cord injury and the developments concerning methods of monitoring, diagnosing, and preventing spinal cord injury. CONCLUSIONS: Translation of novel technologies from bench to bedside and into everyday clinical practice is challenging; however, each of the developing areas holds great promise in spinal cord injury prevention.

Mapping the collateral network: Optimal near-infrared spectroscopy optode placement.

BACKGROUND: Paraplegia after extensive aortic procedures is a disastrous complication, and maintenance of adequate spinal cord perfusion/oxygenation is pivotal to its prevention. Collateral network (CN) near-infrared spectroscopy (cnNIRS) has been introduced as a noninvasive method for indirect spinal cord oxygenation monitoring. However, the CN has not been investigated in its entirety using this monitoring modality. This study aimed to identify the optimal cnNIRS positioning in an acute large animal model for routine clinical use. METHODS: The paraspinous CN was measured from the high thoracic region to the low lumbar region (T4-L5) using cnNIRS in 10 juvenile pigs (plus reference data from 7 animals) during aortic ischemia and reperfusion. These data were compared with data on direct regional tissue perfusion of the CN and the spinal cord. RESULTS: After aortic cross-clamping, cnNIRS at the mid-thoracic to the low lumbar level decreased rapidly to a nadir at 10 minutes of distal ischemia (mean difference, 18.3 ± 11% to 44.5 ± 9%; P < .001 to .045), with more pronounced changes in the caudal regions. High thoracic cnNIRS remained stable (mean difference, 4.3 ± 4%; P = .915). Measurements of cnNIRS, CN, and spinal cord regional perfusion demonstrated comparable curve progressions starting from the mid-thoracic region (r = 0.5-0.7; P < .001). CONCLUSIONS: cnNIRS is capable of detecting relevant changes during ischemia and reperfusion from the mid-thoracic level downward with characteristic oxygenation patterns corresponding to CN and spinal cord regional perfusion. For extensive aortic procedures, noninvasive cnNIRS placement appears to be useful from the mid-thoracic level (T7-T9) to the lower lumbar level (L3-L5) and also may serve as a versatile monitoring method for procedures limited to the proximal thoracic aorta.

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.

Interventions Triggered During Routine Use of NIRS Cerebral Oxygenation Monitoring in Cardiac Surgical Patients.

OBJECTIVE: The purpose of this study was to determine the incidence and types of interventions triggered during a drop of baseline near-infraredspectroscopy (NIRS) values in consecutive cardiac surgical patients. DESIGN: A single-center, retrospective observational study. SETTING: A university-affiliated tertiary care center. PARTICIPANTS: Three thousand three hundred two consecutive cardiac surgical patients from October 2016 to August 2017 Interventions: None. MEASUREMENTS AND MAIN RESULTS: Of the 1,972 patients who met the inclusion criteria, 576 (29.2%) patients showed NIRS deviation of -20% from baseline. Interventions performed during the drop of baseline NIRS values were documented in 285 (14.4%) patients, with a total of 391 interventions. Three hundred fifteen (80%) interventions were triggered by a deviation in NIRS and concomitant changes in standard monitoring parameters. Seventy-six (20%) interventions were triggered by NIRS deviation alone, with no concomitant pathologic deviation in standard monitoring. A total of 279 (71%) interventions were performed on patients who had no recommendation for NIRS monitoring by current national guidelines. Out of these, 30 (7.7%) interventions (1.3% of all patients) were performed based on NIRS monitoring alone. The higher risk deviation group had longer intensive care unit and hospital lengths of stays (one and 15 days) and postoperative delirium when compared with the no-deviation group (zero and 13 days) Conclusions: The authors' data suggested that most interventions triggered during the drop of baseline values during routine use of NIRS would have also been triggered by the concomitant changes in standard monitoring parameters. Routine use of NIRS for all cardiac surgical patients still is debatable and needs to be evaluated in a large prospective trial.

Spinal cord monitoring using collateral network near-infrared spectroscopy during extended aortic arch surgery with a frozen elephant trunk.

The true incidence of spinal cord injury associated with modern hybrid extended arch/descending aortic procedures utilizing a frozen elephant trunk (fET) remains unclear, and it is estimated with ~5-8%. Prolonged distal arrest without sufficient hypothermic protection as well as extended coverage of segmental arteries have been suggested to cause this complication, previously uncommon in open arch surgery. Recently, extensive clinical and experimental research led to the implementation of a new method of collateral network near-infrared spectroscopy (cnNIRS) to non-invasively monitor spinal cord oxygenation in the setting of extensive thoracoabdominal aortic repair. To date, limited experience with this method during arch procedures exists. Based on recent experiments regarding the optimal cnNIRS optode placement, we used this method for the first time during an fET procedure to document mid-thoracic paraspinous oxygenation levels.

Effect of cerebrospinal fluid pressure elevation on spinal cord perfusion during aortic cross-clamping with distal aortic perfusion.

OBJECTIVES: Distal aortic perfusion (DaP) is a widely accepted protective adjunct facilitating early reinstitution of visceral perfusion during extended thoracic and thoraco-abdominal aortic repair. DaP has also been suggested to secure distal inflow to the paraspinal collateral network via the hypogastric arteries and thereby reduce the risk of spinal cord ischaemia. However, an increase in cerebrospinal fluid (CSF) pressure is frequently observed during thoracoabdominal aortic aneurysm repair. The aim of this study was to evaluate the effects of DaP on regional spinal cord blood flow (SCBF) during descending aortic cross-clamping and iatrogenic elevation of cerebrospinal fluid pressure. METHODS: Eight juvenile pigs underwent central cannulation for cardiopulmonary bypass according to our established experimental protocol followed by aortic cross-clamping of the descending thoracic and abdominal aorta-mimicking sequential aortic clamping-with the initiation of DaP. Thereafter, CSF pressure elevation was induced by the infusion of blood plasma until baseline CSF pressure was tripled. At each time-point, microspheres of different colours were injected allowing for regional SCBF analysis. RESULTS: DaP led to a pronounced hyperperfusion of the distal spinal cord [SCBF up to 480%, standard deviation (SD): 313%, compared to baseline]. However, DaP provided no or only limited additional flow to the upper and middle segments of the spinal cord (C1-Th7: 5% of baseline, SD: 5%; Th8-L2: 24%, SD: 39%), which was compensated by proximal flow only at C1-Th7 level. Furthermore, DaP could not counteract an experimental CSF pressure elevation, which led to a further decrease in regional SCBF most pronounced in the mid-thoracic spinal cord segment. CONCLUSIONS: Protective DaP during thoraco-abdominal aortic repair may be associated with inadequate spinal protection particularly at the mid-thoracic spinal cord level ('watershed area') and result in the adverse effect of a potentially dangerous hyperperfusion of the distal spinal cord segments.

Experimental near-infrared spectroscopy-guided minimally invasive segmental artery occlusion.

OBJECTIVES: Minimally invasive staged segmental artery (SA) coil- and plug embolization is a new method for paraplegia prevention associated with extensive aortic procedures. Near-infrared spectroscopy of the paraspinal collateral network (cnNIRS) has emerged as a non-invasive method for spinal cord monitoring. The aim of this study was to evaluate cnNIRS to guide minimally invasive SA occlusion. METHODS: In a chronic large animal experiment, 18 juvenile pigs underwent two-stage minimally invasive staged SA coil- and plug embolization for complete SA occlusion. Coil-embolization was performed either by SA main stem occlusion (characteristic of pig anatomy) or separately for the left- and right SA. Lumbar cnNIRS was recorded during and after the procedure. Neurological status was assessed up to 3 days after complete SA occlusion. RESULTS: Mean time from SA coil embolization to minimum cnNIRS values was 11 ± 5 min with an average decrease from 101 ± 2% to 78 ± 8% of baseline (difference: -23 ± 9, P < 0.001). Lumbar cnNIRS demonstrated significant differences between left and right when SAs were occluded separately in all cases (-7 ± 4%, 1 min after first SA occlusion; P = 0.001). Permanent paraplegia occurred in 2 (11%) and any kind of neurological deficit-temporary or permanent-in 7 animals (39%). Association between lumbar cnNIRS and neurological outcome after minimally invasive staged SA coil- and plug embolization suggests positive correlation (R = 0.5, P = 0.052). CONCLUSIONS: Lumbar cnNIRS independently reacts to unilateral SA occlusion. cnNIRS-guided SA occlusion is feasible and may become a useful adjunct facilitating adequate and complete vessel occlusion.

Impact of a surgical approach for implantation of durable left ventricular assist devices in patients on extracorporeal life support.

BACKGROUND: The aim of this study was to evaluate the impact of the surgical approach on the postoperative outcome in patients who underwent left ventricular assist device (LVAD) implantation after having received veno-arterial extracorporeal life support (va-ECLS) using data from a European registry (ECLS-VAD). Five hundred and thirty-one patients were included. METHODS: A propensity score-adjusted outcome analysis was performed, resulting in 324 patients in the full sternotomy (FS) group and 39 in the less invasive surgery (LIS) group. RESULTS: The surgery lasted in median 236 min in the FS group versus 263 min in the LIS group (p = 0.289). The median chest tube output during the first 24 h was similar in both groups. Patients who underwent implantation with an FS required more blood products during the first 24 postoperative hours (median 16 vs. 12, p = 0.033). The incidence of revision due to bleeding was also higher (35.5 vs. 15.4%, p = 0.016). A temporary postoperative right ventricular assist device was necessary in 45.1 (FS) versus 23.1% (LIS) of patients, respectively (p = 0.067). No stroke occurred in the LIS group during the first 30 days after surgery (7.4% in the FS group). The incidence of stroke and of renal, hepatic, and respiratory failure during the follow-up was similar in both groups. The 30-day and one-year survival were similar in both groups. CONCLUSION: LIS for implantation of a durable LVAD in patients on va-ECLS implanted for cardiogenic shock is associated with less revision due to bleeding, less administration of blood products and absence of perioperative stroke, with no impact on survival.

Spinal cord protection in thoracoabdominal aortic aneurysm surgery: a multimodal approach.

Spinal cord injury (SCI) is one major complication of open and endovascular thoracic and thoracoabdominal aortic aneurysm repair. Despite numerous neuroprotective adjuncts, the incidence of SCI remains high. This review article discusses established and novel adjuncts for spinal cord protection, including priming and preconditioning of the paraspinal collateral network, intraoperative systemic hypothermia, distal aortic perfusion, motor- and somatosensory evoked potentials and noninvasive cnNIRS monitoring as well as peri- and postoperative drainage of cerebrospinal fluid. Regardless of the positive influence of many of these strategies on neurologic outcome, to date no strategy assures definitive preservation of spinal cord integrity during and after aortic aneurysm repair.