Sex-related differences in outcome of thoracic aortic surgery.

BACKGROUND: Sex-related dissimilarities' influence on outcomes following thoracic aortic surgery is poorly understood. Our aim is to examine sex-related disparities in patients undergoing thoracic aortic aneurysm (TAA). METHODS: A total of 455 cases undergoing thoracic aortic aneurysm (TAA) surgery were consecutively enrolled between December 2009 and December 2015 in a Chinese hospital. Primary outcomes, including overall mortality and related risk factors, were evaluated. Cox regression is utilized to recognize the independent risk factor of these consequences. RESULTS: Females, compared to males, had greater indexed aortic diameters and higher aortic transvalvular pressure differences. For the location of aortic aneurysms, females had a higher rate of aortic arch involvement, while males had a higher rate of root involvement. Females underwent less frequent complex proximal aortic operations compared with males (29.5% versus 46.9%; p < 0.001). Women and men both had a lower rate of aortic transvalvular pressure difference and LV volume index 7 days after thoracic aortic surgery. The overall mortality for the women's groups (11%) was suggestively greater compared to 4.9% for the men's groups (p = 0.026). Renal failure and aortic arch involvement were the main risk factors associated with males' survival, while maximum indexed aortic diameter and cross-clamp time were the risk factors associated with females' survival. CONCLUSIONS: The outcome after TAA surgery was less favorable in women with significantly increased overall mortality. It highlights the need to focus on implementing personalized surgery strategies and gender-specific guidelines in treating female patients following TAA surgery.

Recombinant Activated Factor VII (rFVIIa) for Bleeding After Thoracic Aortic Surgery: A Scoping Review of Current Literature.

BACKGROUND: Bleeding after surgery on the thoracic aorta is a frequent complication, and can be associated with a significant increase in morbidity and mortality. Recombinant activated factor VII (rFVIIa) was developed initially for treating patients with hemophilia; however, it has been used increasingly "off-label" to achieve hemostasis after thoracic aortic procedures. OBJECTIVE: This scoping review aimed to present the available literature on the role of rFVIIa in the management of refractory postoperative bleeding after thoracic aortic surgery. METHODS/RESULTS: An electronic database search was conducted using Medline, Embase, Cochrane Library, and Google Scholar in June 2023. The authors included studies that reported the use of rFVIIa in patients undergoing surgical repair of ascending or descending aortic aneurysm or dissection. Single-case reports were excluded. Ten publications with a pooled number of 649 patients (319 patients received rFVIIa and 330 in the control groups) were identified: 3 case series, 6 retrospective studies, and 1 nonrandomized clinical trial. All studies reported the potential role of rFVIIa in correcting coagulopathy and reducing postoperative blood loss in this group of patients. Overall, there was not enough evidence to suggest that rFVIIa was associated with higher rates of thromboembolic complications or mortality. CONCLUSION: Limited evidence suggests that rFVIIa may be useful in managing postoperative refractory bleeding in patients undergoing thoracic aortic surgery. However, the impact of rFVIIa on thromboembolic complications and mortality rates remains unclear.

Mediastinal perigraft seroma after thoracic aortic surgery.

OBJECTIVES: We investigated pertinent factors associated with mediastinal perigraft seroma (PGS) after thoracic aortic surgery. In addition, we provided a clinical review of this entity, as reports reviewing abundant mediastinal PGS cases are rare. METHODS: Eighty-two patients who underwent either ascending aortic replacement or aortic arch replacement between 2016 and 2022 in our institution were enrolled in the present study. Postoperative computed tomography scans were performed to detect fluid capsules with a diameter ≥3.0 cm and radiodensity ≤25 Hounsfield units. Patients who did and who did not develop PGS formation were compared. Variables with a statistically significant difference between these groups were included in a multiple logistic regression analysis along with other factors associated with PGS in the literature. RESULTS: The incidence rate of PGS was 14.6% (12/82). The average radiodensity of the mass was 16.6 ± 6.3 Hounsfield units. The average onset of PGS was 8.5 months post-surgery. Multivariate logistic regression analysis revealed that ejection fraction [odds ratio (OR): 1.25, 95% confidence interval (CI): 1.03-1.50, P = 0.021], aortic dissection (versus degenerative aortic aneurysm) (OR: 6.61, 95% CI: 1.35-32.4, P = 0.02) and warfarin use (OR: 6.67, 95% CI: 1.19-37.1, P = 0.03) significantly contributed to mediastinal PGS after thoracic aortic surgery. CONCLUSIONS: High ejection fraction, warfarin use and aortic dissection (versus degenerative aortic aneurysm) contributed significantly to mediastinal PGS formation after thoracic aortic surgery. Careful serial postoperative imaging studies and fluid analysis can be used to guide treatment plans. CLINICAL TRIAL REGISTRATION: UMIN-CTR (University hospital Medical Information Network-Clinical Trial Registry) Registration number: UMIN000050764.

Granulomatous inflammation mimicking a hematoma around the replaced ascending aorta in magnetic resonance imaging: a case report.

BACKGROUND: Granulomatous inflammation results from various causes including infections and allergic reactions. It can appear as high signal intensity in T2-weighted or contrast-enhanced T1-weighted magnetic resonance imaging (MRI). Here, we describe a case of granulomatous inflammation looking like a hematoma on an ascending aortic graft in MRI. CASE PRESENTATION: A 75-year-old female was undergoing assessment for chest pain. She had a history of hemi-arch replacement for aortic dissection 10 years earlier. The initial chest computed tomography and subsequent chest MRI were suggestive of a hematoma, implying a pseudoaneurysm of the thoracic aorta, which is associated with high mortality in reoperation. Through redo median sternotomy, severe adhesion was found in the retrosternal space. A sac in the pericardial space contained yellowish and pus-like material, confirming that there was no hematoma around the ascending aortic graft. The pathologic finding was chronic necrotizing granulomatous inflammation. Microbiological tests including polymerase chain reaction analysis were negative. CONCLUSION: Our experience indicates that an MRI finding of a hematoma at the site long after cardiovascular surgery suggests that there may be granulomatous inflammation.

Determination of selective antegrade perfusion flow rate in aortic arch surgery to restore baseline cerebral near-infrared spectroscopy values: a single-centre observational study.

OBJECTIVES: Neuroprotection during aortic arch surgery involves selective antegrade cerebral perfusion. The parameters of cerebral perfusion, e.g. flow rate, are inconsistent across centres and are subject of debate. The aim of this study was to determine the cerebral perfusion flow rate during hypothermic circulatory arrest required to meet preoperative awake baseline regional cerebral oxygen saturation (rSO2). METHODS: Patients scheduled for aortic arch surgery with hypothermic circulatory arrest were enrolled in this prospective observational study. After initiation of hypothermic circulatory arrest, bilateral selective antegrade cerebral perfusion was established and cerebral flow rate was continuously increased. The primary end point was the difference of cerebral saturation from baseline during cerebral perfusion flow rates of 6, 8 and 10 ml/kg/min. RESULTS: A total of 40 patients were included. During antegrade cerebral perfusion, rSO2 was significantly lower than the baseline at 6 ml/kg/min [-7.3, 95% confidence interval (CI): -1.7, -12.9; P = 0.0015]. In contrast, flow rates of 8 and 10 ml/kg/min resulted in rSO2 that did not significantly differ from the baseline (-2; 95% CI: -4.3, 8.3; P > 0.99 and 1.8; 95% CI: -8.5%, 4.8%; P > 0.99). Cerebral saturation was significantly more likely to meet baseline values during selective antegrade cerebral perfusion with 8 ml/kg/min than at 6 ml/kg/min (44.1%; 95% CI: 27.4%, 60.8% vs 11.8%; 95% CI: 0.9%, 22.6%; P = 0.0001). CONCLUSIONS: At 8 ml/kg/min cerebral flow rate during selective antegrade cerebral perfusion, regional cerebral oximetry baseline values are significantly more likely to be achieved than at 6 ml/kg/min. Further increasing the cerebral flow rate to 10 ml/kg/min does not significantly improve rSO2.

Knowledge, attitudes, and practice preferences in the surgical threshold for ascending aortic aneurysm among Canadian cardiac surgeons.

OBJECTIVE: The survey aimed to assess the practice patterns of Canadian cardiac surgeons on the size threshold at which patients with ascending aortic aneurysm would be offered surgery. METHODS: A 18-question electronic survey was electronically distributed to 148 practicing cardiac surgeons in Canada via email from January to August 2020. Questions presented clinical scenarios focusing on modifying a single variable, and respondents were asked to identify their surgical size threshold for each of the clinical scenarios. RESULTS: The individual response rate was 62.0% (91/148) and institutional response rate was 89.3% (25/29). For an incidental asymptomatic ascending aortic aneurysm in a 60-year-old otherwise-healthy male patient with a tricuspid aortic valve and bicuspid aortic valve of 1.9 m2, 20.2% of the respondents would recommend surgery when the aneurysm was <5.5 cm. A significant number of surgeons modified their surgical threshold in response to changes to BSA, bicuspid aortic valve, growth rate, age, occupation, symptom, and family history (P < .01). Notably, if the patient had a bicuspid aortic valve, 41.0% of respondents lowered their threshold for surgery, with only 43.0% recommending surgery at ≥5.5 cm (P < .01). CONCLUSIONS: Practice variations exist in the current size threshold for surgery of ascending aortic aneurysms in Canada. These differences between surgeons are further accentuated in the context of bicuspid aortic valve, smaller body stature, younger age, low growth rate, family history, and for the performance of isometric exercise. These represent important areas where future prospective studies are required to inform best practice.

Association between frailty and long-term outcomes among patients undergoing thoracic aortic surgery via median sternotomy.

OBJECTIVE: Preoperative assessment of frailty is important for predicting postoperative outcomes. This study investigated the association between frailty and late outcomes among patients who underwent thoracic aortic surgery via median sternotomy. METHODS: A total of 1010 patients underwent thoracic aortic surgery via median sternotomy between April 2008 and December 2016. Patients < 65 years of age, those who underwent urgent or emergent surgery, and those with incomplete data were excluded; as such, 374 patients were ultimately included in the present study. Frailty was evaluated using an index comprising history of dementia, body mass index < 18.5 kg/m2, and hypoalbuminemia. A frailty score from 0 to 3 was determined by assigning 1 point for each criterion met. Frailty was defined as a score ≥ 1. Patients were categorized into of 2 groups: frail (n = 52) and non-frail (n = 322). The mean follow-up was 6.1 ± 3.1 years. RESULTS: Overall in-hospital mortality did not differ between the frail and non-frail groups. However, the incidence of re-exploration for bleeding and discharge to a health care facility was higher in the frail group than in the non-frail group. Multivariable analysis revealed that preoperative frailty was an independent predictor of late mortality during follow-up [hazard ratio 3.71 (95% confidence interval 2.16-6.37); P < 0.001]. CONCLUSION: Preoperative frailty was associated with late mortality after thoracic aortic surgery. Assessment of preoperative frailty using a simple frailty index may be useful in the decision-making process for elderly patients.

Effect of fibrinogen replacement therapy on bleeding outcomes and 1-year mortality in patients undergoing thoracic aortic surgery: a retrospective cohort study.

PURPOSE: This study aimed to examine the effect of fibrinogen replacement therapy with cryoprecipitate or fibrinogen concentrate on bleeding outcomes and 1-year mortality in patients undergoing thoracic aortic surgery. METHODS: We retrospectively studied 439 consecutive patients who underwent thoracic aortic surgery with cardiopulmonary bypass between January 1st, 2010 and December 31st, 2019 and identified patients who received cryoprecipitate or fibrinogen concentrate (the fibrinogen replacement group) and those who did not (the control group). Multivariate analyses were performed to examine the associations of fibrinogen replacement therapy with perioperative major bleeding (i.e., excessive hemorrhage or blood transfusion), re-exploration for bleeding, and 1-year mortality. RESULTS: There were 285 patients in the fibrinogen replacement group who received 2.2 ± 1.0 g of concentrated fibrinogen amount and 154 patients in the control group. The incidence of major bleeding in the fibrinogen replacement group was less than that in the control group in patients with fibrinogen level < 150 mg/dL during cardiopulmonary bypass (49.7% versus 74.6%, p = 0.0007, multivariate odds ratio; 0.33, 95% confidence intervals; 0.12-0.91, p = 0.03), but not in patients with fibrinogen level ≥ 150 mg/dL (25.0% versus 29.6%, p = 0.51). No significant difference was found in re-exploration for bleeding (1.0% versus 1.3%, p = 1.00) or 1-year mortality (10.4% versus 5.3%, multivariate Cox proportional-hazard ratio; 1.03, 95% confidence intervals; 0.82-1.31, p = 0.74) between the fibrinogen replacement group and the control group. CONCLUSIONS: The results of this study indicate that 2-3 g of fibrinogen replacement reduces the incidence of major bleeding in patients with hypofibrinogenemia during cardiopulmonary bypass in thoracic aortic surgery.

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.

Triplex vascular prostheses elongation in post-operative course.

Triplex (Terumo Corp, Tokyo, Japan) is a relatively new vascular protheses with a non-biodegradable coating material. We experienced two cases of graft elongation in Triplex grafts post-operatively. In one of the cases, the graft elongation led to occlusion of the left subclavian artery. In the other case, the graft elongation resulted in a pseudoaneurysm of the ascending aorta. A unique feature of Triplex grafts is that they may reduce post-operative inflammation reaction; however, they could also invite a limited adhesion formation with the surrounding tissue, which contribute to prostheses elongation, due to a lack of prostheses stability and fixation. A careful observation based on the feature of implanted protheses is required.

The effect of posterior pericardiotomy after thoracic aortic surgery.

BACKGROUND: Postoperative pericardial effusion is common after cardiovascular surgery. We aimed to examine the effectiveness of posterior pericardiotomy in reducing the incidence of postoperative pericardial effusion and postoperative atrial fibrillation after thoracic aortic surgery. METHODS: This study included 201 patients who underwent thoracic aortic open surgery between January 2014 and November 2021. We compared surgical outcomes between patients who underwent posterior pericardiotomy and those who did not. RESULTS: The group that did not undergo posterior pericardiotomy had significantly longer mechanical ventilation duration than the group who did, both in the overall (p = 0.005) and in the propensity-matched cohorts (p = 0.001). The lengths of intensive care unit and hospital stays were significantly longer in the group that did not undergo posterior pericardiotomy compared to the group that did, both in the overall and in the propensity-matched cohorts. The occurrence of postoperative atrial fibrillation and stroke did not differ significantly between the two groups. The amount of pericardial drainage was not significantly lower in the group that underwent posterior pericardiotomy in the overall cohorts (p = 0.09), but the difference was significant in the propensity-matched cohorts (p = 0.04). The amount of mediastinal drainage was significantly lower in the group that underwent posterior pericardiotomy, both in the overall cohorts (< 0.001) and in the propensity-matched cohort (< 0.001). Late pericardial tamponade occurred significantly more frequently in the group that did not undergo posterior pericardiotomy than in the group that did, both in the overall (p = 0.03) and in the propensity-matched cohorts (p = 0.03). CONCLUSIONS: Posterior pericardiotomy has no effect on reducing postoperative atrial fibrillation after thoracic aortic surgery. However, posterior pericardiotomy reduced the occurrence of late pericardial tamponade, length of ICU stay, length of hospital stay, and mechanical ventilation duration after surgery.

Risk factors for impaired neurological outcome after thoracic aortic surgery.

Background: We aimed to identify risk factors for an impaired postoperative neurological outcome after thoracic aortic surgery. Methods: Data from all patients undergoing thoracic aortic surgery between 2010 and 2020 at our institution were collected and analyzed retrospectively. Logistic regression analysis was used to identify independent risk factors for permanent postoperative neurological deficit (ND) (stroke), which was defined as a ND lasting at least seven days. Results: Thoracic aortic surgery was performed in 1,334 patients. Of these, 286 (21.4%) underwent emergency surgery. The mean EuroSCORE II was 8.6±10.1. A perioperative stroke occurred in 94 patients (7.0%). Of all strokes, 62.8% (n=59) were considered of embolic and 24.5% (n=23) of hemodynamic origin. In elective procedures, stroke rates ranged from 0.5% after valve-sparing root replacement to 8.1% after arch surgery. Adjusted logistic regression identified advanced age [>70 years; odds ratio (OR), 1.83; P=0.009], acute type A dissection (ATAD) (OR, 1.69; P=0.0495), aortic arch surgery (OR, 3.24; P<0.001), concomitant coronary artery bypass grafting (CABG) (OR, 2.19; P=0.005), and high extracorporeal circulation (ECC) time (>230 min; OR, 1.70; P=0.034) as independent risk factors for all strokes. Secondary endpoint analyses revealed that risk factors for hemodynamic stroke were arch surgery, advanced age (>70 years), atherosclerosis, and ATAD. Risk factors for embolic stroke were arch surgery, concomitant CABG and preoperative cerebral malperfusion. Conclusions: Identified independent risk factors for all strokes were advanced age, ATAD, arch surgery, concomitant CABG, and high ECC time. Hemodynamic and embolic strokes show distinct risk profiles.

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. Supplementary Information: The online version contains supplementary material available at 10.1007/s12055-021-01258-2.

Prediction of Acute Kidney Injury by Cystatin C and [TIMP-2]*[IGFBP7] after Thoracic Aortic Surgery with Moderate Hypothermic Circulatory Arrest.

(1) Background: Acute kidney injury (AKI) is a common complication following thoracic aortic surgery (TAS), with moderate hypothermic circulatory arrest (MHCA). However, prediction of AKI with classical tools remains uncertain. Therefore, it was the aim of the present study to evaluate the role of new biomarkers in patients after MHCA. (2) Methods: 101 consecutive patients were prospectively enrolled. Measurements of urinary [TIMP-2]*[IGFBP7] and Cystatin C in the blood were performed perioperatively. Primary endpoint was the occurrence of AKI stage 2 or 3 (KDIGO-classification) within 48 h after surgery (AKI group). (3) Results: Mean age of patients was 69.1 ± 10.9 years, 35 patients were female (34%), and 13 patients (13%) met the primary endpoint. Patients in the AKI group had a prolonged ICU-stay (6.9 ± 7.4 days vs. 2.5 ± 3.1 days, p < 0.001) as well as a higher 30-day-mortality (9/28 vs. 1/74, p < 0.001). Preoperative serum creatinine (169.73 ± 148.97 µmol/L vs. 89.74 ± 30.04 µmol/L, p = 0.027) as well as Cystatin C (2.41 ± 1.54 mg/L vs. 1.13 ± 0.35 mg/L, p = 0.029) were higher in these patients. [TIMP-2]*[IGFBP7] increased significantly four hours after surgery (0.6 ± 0.69 mg/L vs. 0.37 ± 0.56 mg/L, p = 0.03) in the AKI group. Preoperative Cystatin C (AUC 0.828, p < 0.001) and serum creatinine (AUC 0.686, p = 0.002) as well as [TIMP-2]*[IGFBP7] 4 h after surgery (AUC 0.724, p = 0.020) were able to predict postoperative AKI. The predictive capacity of Cystatin C was superior to serum creatinine (p = 0.0211) (4) Conclusion: Cystatin C represents a very sensitive and specific biomarker to predict AKI in patients undergoing thoracic surgery with MHCA even before surgery, whereas the predictive capacity of [TIMP-2]*[IGFBP7] is only moderate and inferior to that of serum creatinine.

Association between prehospital transfer distance and surgical mortality in emergency thoracic aortic surgery.

OBJECTIVE: To examine whether there is an association between prehospital transfer distance and surgical mortality in emergency thoracic aortic surgery. METHODS: A retrospective cohort study using a national clinical database in Japan was conducted. Patients who underwent emergency thoracic aortic surgery from January 1, 2014, to December 31, 2016, were included. Patients with type B dissection were excluded. A multilevel logistic regression analysis was performed to examine the association between prehospital transfer distance and surgical mortality. In addition, an instrumental variable analysis was performed to address unmeasured confounding. RESULTS: A total of 12,004 patients underwent emergency thoracic aortic surgeries at 495 hospitals. Surgical mortality was 13.8%. The risk-adjusted mortality odds ratio for standardized distance (mean 12.8 km, standard deviation 15.2 km) was 0.94 (95% confidence interval, 0.87-1.01; P = .09). Instrumental variable analysis did not reveal a significant association between transfer distance and surgical mortality as well. CONCLUSIONS: No significant association was found between surgical mortality and prehospital transfer distance in emergency thoracic aortic surgery cases. Suspected cases of acute thoracic aortic syndrome may be transferred safely to distant high-volume hospitals.

Postoperative and mid-term hemodynamic changes after replacement of the ascending aorta.

OBJECTIVES: To evaluate aortic distensibility and pulse waveform patterns associated with the ascending aortic aneurysm, and to analyze the postoperative and mid-term hemodynamic changes induced by prosthetic replacement of the ascending aorta. METHODS: Central blood pressure waves were recorded at the carotid artery level by means of a validated transcutaneous arterial tonometer in 30 patients undergoing prosthetic replacement of ascending aortic aneurysm and in 30 control patients. Measurements were obtained the day before surgery and 5 to 7 days and 16 to 20 months after surgery. RESULTS: The ascending aortic aneurysm was associated with a less steep slope of early systolic phase of the pressure curve (pulsus tardus) compared with a control group (0.54 ± 0.18 mm Hg/ms vs 0.69 ± 0.26 mm Hg/ms; P = .011). Replacing the ascending aorta with a noncompliant vascular prosthesis steepened the pulse pressure slope during the early systolic phase in the postoperative period (0.77 ± .29 mm Hg/ms), providing values comparable with those of the control group in the mid-term (0.67 ± .20 mm Hg/ms). No change in aortic stiffness was found either postoperatively or in the mid-term after ascending aorta surgical replacement (carotid-femoral pulse wave velocity: preoperative, 9.0 ± 2.6 m/s; postoperative, 9.0 ± 2.9 m/s; mid-term postoperative, 9.3 ± 2.8 m/s). CONCLUSIONS: This study does not confirm the assumption that substitution of the viscoelastic ascending aorta with a rigid prosthesis can cause serious hemodynamic alterations downstream, because we did not observe a worsening of global aortic distensibility after insertion of a rigid prosthetic aorta. The ascending aortic aneurysm is associated with a pulsus tardus.

Does deeper hypothermia reduce the risk of acute kidney injury after circulatory arrest for aortic arch surgery?

OBJECTIVES: The impact of hypothermic circulatory arrest (HCA) temperature on postoperative acute kidney injury (AKI) has not been evaluated. This study examined the association between circulatory arrest temperatures and AKI in patients undergoing proximal aortic surgery with HCA. METHODS: A total of 759 consecutive patients who underwent proximal aortic surgery (ascending ± valve ± root) including arch replacement requiring HCA between July 2005 and December 2016 were identified from a prospectively maintained institutional aortic surgery database. The primary outcome was AKI as defined by Risk, Injury, Failure, Loss, End Stage Renal Disease (ESRD) criteria. The association between minimum nasopharyngeal (NP) and bladder temperatures during HCA and postoperative AKI was assessed, adjusting for patient-level factors using multivariable logistic regression. RESULTS: A total of 85% (n = 645) of patients underwent deep hypothermia (14.1-20.0°C), 11% (n = 83) low-moderate hypothermia (20.1-24.0°C) and 4% (n = 31) high-moderate hypothermia (24.1-28.0°C) as classified by NP temperature. When analysed by bladder temperature, 59% (n = 447) underwent deep hypothermia, 22% (n = 170) low-moderate, 16% (n = 118) high-moderate and 3% mild (n = 24) (28.1-34.0°C) hypothermia. The median systemic circulatory arrest time was 17 min. The incidence of AKI did not differ between hypothermia groups, whether analysed using minimum NP or bladder temperature. In the multivariable analysis, the association between degree of hypothermia and AKI remained non-significant whether analysed as a categorical variable (hypothermia group) or as a continuous variable (minimum NP or bladder temperature) (all P > 0.05). CONCLUSIONS: In patients undergoing proximal aortic surgery including arch replacement requiring HCA, degree of systemic hypothermia was not associated with the risk of AKI. These data suggest that moderate hypothermia does not confer increased risk of AKI for patients requiring circulatory arrest, although additional prospective data are needed.

Intravenous injection of adult human bone marrow mesenchymal stromal cells attenuates spinal cord ischemia/reperfusion injury in a murine aortic arch crossclamping model.

Objective: We sought to investigate the efficacy of human bone marrow mesenchymal stem/stromal cell (hBM-MSC) in a murine spinal cord ischemia/reperfusion (SCIR) model. Methods: C57BL/6J mice were subjected to SCIR by crossclamping the aortic arch and left subclavian artery for 5.5 minutes. Two hours after reperfusion, hBM-MSCs (hBM-MSC group) or phosphate-buffered saline (control group) were intravenously injected without immunosuppressant. Hindlimb motor function was assessed until day 28 after reperfusion using the Basso Mouse Scale (BMS). The lumbar spinal cord was harvested at hour 24 and day 28, and the histologic number of NeuN-positive motor neurons in 3 cross-sections of each lumbar spinal cord and the gene expression were evaluated. Results: BMS score was 0 throughout the study period in all control mice. BMS score was significantly greater in the hBM-MSC group than the control group from hour 8 (P < .05) to day 28 (P < .01). The numbers of motor neurons at hour 24 (P < .01) and day 28 (P < .05) were significantly preserved in the hBM-MSC group than the control group. mRNA expression levels of proinflammatory cytokines were significantly lower (P < .05), and those of insulin-like growth factor-1 (P < .01) and proangiogenic factors (P < .05) were significantly greater in the hBM-MSC group than the control group at hour 24. Conclusions: hBM-MSC therapy may attenuate SCIR injury by preserving motor neurons, at least in part, through inhibition of proinflammatory cytokines and upregulation of proangiogenic factors in the reperfusion-injured spinal cord.

Chronic kidney disease stage stratifies short- and long-term outcomes after aortic root replacement.

OBJECTIVES: Chronic kidney disease (CKD) is prevalent in patients undergoing cardiovascular surgery, and it negatively impacts procedural outcomes; however, its influence on the outcomes of aortic surgery has not been well studied. This study aims to elucidate the importance of CKD on the outcomes of aortic root replacement (ARR). METHODS: Patients who underwent ARR between 2005 and 2019 were retrospectively reviewed (n = 882). Patients were divided into 3 groups based on the Kidney Disease: Improving Global Outcomes criteria: Group 1 [estimated glomerular filtration rate (eGFR) ≥ 60 ml/min/1.73 m2, n = 421); Group 2 (eGFR = 30-59 ml/min/1.73 m2, n = 424); and Group 3 (eGFR < 30 ml/min/1.73 m2, n = 37). To reduce potential confounding, a propensity score matching was also performed between Group 1 and the combined group of Group 2 and Group 3. The primary end point was 10-year survival. Secondary end points were in-hospital mortality and perioperative morbidity. RESULTS: Severe CKD patients presented with more advanced overall chronic and acute illnesses. Kaplan-Meier analysis showed a significant correlation between CKD stage and 10-year survival (log-rank P < 0.001). The number of events for Group 1 was 15, Group 2 was 49 and Group 3 was 11 in 10 years. Group 3 had significantly higher in-hospital mortality (13.5% vs 3.5% in Group 2 vs 0.7% in Group 1, P < 0.001) and stroke (8.1% vs 7.1% vs 1.2%, P < 0.001) as well as introduction to new dialysis (27.0% vs 5.4% vs 1.7%, P < 0.001). eGFR was shown to be an independent predictor of mortality (hazard ratio, 0.98; 95% confidence interval, 0.96-0.99). Comparison between propensity matched groups showed similar postoperative outcomes, and eGFR was still identified as a predictor of mortality (hazard ratio, 0.97; 95% confidence interval, 0.95-0.99). CONCLUSIONS: Higher stage in CKD negatively impacts the long-term survival in patients who are undergoing ARR.