Aortic Dissection Surgery Research Articles

Correlation between cerebral oxygen saturation monitored by near-infrared spectroscopy during operation and risk of stroke after acute type A aortic dissection surgery

Objective: Near-infrared spectroscopy (NIRS) is widely used for intraoperative cerebral oxygen saturation monitoring in patients with acute type A aortic dissection. This study aimed to investigate the correlation between NIRS-derived oxygen saturation and risk of postoperative stroke. Methods: This study included 193 patients with acute type A aortic dissection undergoing emergency surgery and elective unilateral cerebral perfusion via the right axillary artery at the Department of Cardiothoracic Surgery, Nanjing Drum Tower Hospital, Nanjing, China, from 2018 to 2020. NIRS was used for intraoperative cerebral oxygen saturation monitoring, and the basal values and the lowest values of cerebral oxygen saturation during deep hypothermic circulatory arrest (DHCA) were recorded. The patients were divided into no-stroke group (n=178, 92.2%) and stroke group (n=15, 7.8%) according to the absence or presence of postoperative stroke. The differences in preoperative, operative and postoperative clinical differences between the two groups were compared, and the relationship between the lowest cerebral oxygen saturation value and the change in cerebral oxygen saturation value ((base-lowest)/basal) and postoperative stroke were analyzed. Results: The proportion of preoperative atrial fibrillation (6.7% vs. 0.6%, P=0.026), and the proportion of preoperative hypotension (26.7% vs. 9.0%, P=0.031) were significantly higher in the stroke group than no-stroke group. There were no differences in the surgical approach between the two groups. Cardiopulmonary bypass (CPB) time ((256.1±84.8) h vs.(217.8±58.4) h, P=0.020), postoperative mechanical ventilation time ((139.3±172.8) h vs. (35.6±45.6) h, P<0.001) were significantly longer in stroke group as compared to no-stroke group. Incidence of postoperative tracheotomy (20.0% vs. 1.1%, P<0.001), acute kidney injury (73.3% vs. 30.3%, P=0.001) and continuous renal replacement therapy (46.7% vs. 11.8%, P<0.001) as well as mortality (20.0% vs. 5.1%, P=0.022) were significantly higher in the stroke group than in non-stroke group. There was no significant difference in the basal NIRS value and the lowest NIRS value during DHCA between the two groups. Patients in the stroke group had a significantly greater intraoperative change rate of right NIRS as compared to no-stroke group (15.2%±15.7% vs. 9.2%±7.0%, P=0.006). Conclusions: NIRS is valuable for monitoring cerebral oxygen saturation during acute type A aortic dissection surgery, and the rate change of NIRS during operation correlates significantly with postoperative stroke.

Left axillary cannulation for acute type A aortic dissection

The most commonly used arterial cannulation sites for type A aortic dissection are right axillary artery, femoral artery and both. Direct central aortic cannulation has also been reported. In rare cases, it is extremely difficult to choose an arterial cannulation site for type A aortic dissection due to involvement of the right axillary and both femoral arteries. Herein, we present a 39-year-old male with acute type A aortic dissection with involvement of the right axillary and both femoral arteries. Left axillary cannulation was made and selective cerebral perfusion was performed through direct left common carotid artery cannulation during circulatory arrest. Surgery was performed to replace the ascending aorta and total arch combined with a frozen elephant trunk implantation. The patient recovered uneventfully. To our knowledge, this is a rare case of total aortic arch replacement with frozen elephant trunk implantation through left axillary arterial cannulation for type A aortic dissection in the literature. Left axillary cannulation is a safe and useful choice for type A aortic dissection surgery when right axillary and femoral cannulation are not safe and reliable.

Effect of waiting time for COVID-19 screening on postoperative outcomes of type A aortic dissection: An institutional study.

BackgroundSince November 2020, all patients undergoing emergency surgery at our hospital have been subjected to preoperative reverse transcription polymerase chain reaction (RT-PCR) screening to prevent nosocomial COVID-19 infection, with admission to the operating room requiring a negative result. Herein, we compared the pre- and postoperative outcomes of acute type A aortic dissection surgery before and after implementing the RT-PCR screening for all patients.MethodsWe compared the postoperative results of 105 patients who underwent acute type A aortic dissection emergency surgery from January 2019 to October 2020 (Group I) and 109 patients who underwent the surgery following RT-PCR screening from November 2020 to March 2022 (Group II).ResultsThe average waiting time from arrival at the hospital to admission to the operating room was 36 and 81 min in Groups I and II, respectively. Ruptured cardiac tamponade was observed preoperatively in 26.6% and 21.1% of Groups I and II patients, respectively. The preoperative waiting time due to RT-PCR screening did not contribute to the cardiac tamponade. Surgical complications such as bleeding (reopened chest), respiratory failure, cerebral neuropathy, or mediastinitis did not increase significantly. The number of deaths 30 days after surgery (Group I = 13 and Group II = 3) showed no significant difference between the groups. There were no cases of nosocomial COVID-19 infections.ConclusionsPreoperative COVID-19 screening is an important method to prevent nosocomial infections. The associated waiting time did not affect the number of preoperative ruptures or affect postoperative complications or mortality.

Impact of fluid balance and blood transfusion during extracorporeal circulation on outcome for acute type A aortic dissection surgery.

In thoracic aortic surgery, fluid replacement and blood transfusion during extracorporeal circulation (ECC) are associated with increased coagulopathy, elevated inflammatory response, and end-organ dysfunction. The optimal strategy has not been established in this regard. The aim of this study was to evaluate the effect of the fluid balance during ECC in thoracic aortic dissection surgery on outcome. Between 2009 and 2020, 358 patients suffering from acute type A aortic dissection (ATAAD) underwent aortic surgery at our heart center. In-hospital mortality, major complications (postoperative stroke, respiratory failure, heart failure, acute renal failure), and follow-up mortality were assessed. Logistic regression analysis was used to identify whether fluid balance and blood transfusion during ECC were risk factors for occurring adverse events. The in-hospital mortality amounted to 20.4%. Major complications included temporary neurologic deficit in 13.4%, permanent neurologic deficit in 6.1%, acute renal failure in 32.7%, prolonged ventilation for respiratory failure in 17.9%, and acute heart failure in 10.9% of cases. At a mean of 42 months after discharge of 285 survivors, follow-up mortality was 13.3%. Multivariate analysis revealed major complications as well as the risk of in-hospital and follow-up mortality to increase with fluid balance and blood transfusion during ECC. Fluid balance and blood transfusion during ECC present with predictive potential concerning the risk of postoperative adverse events.

TG/HDL-C ratio predicts in-hospital mortality in patients with acute type A aortic dissection

BackgroundIn recent years, abnormalities in serum lipids and lipoproteins have been shown to be associated with cardiovascular disease risk. However, their prognostic value for acute type A aortic dissection is unclear. This study analyzed the correlation between triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) ratio and in-hospital mortality in patients with AAAD, and aimed to investigate the clinical significance of preoperative blood lipids and lipoproteins on the prognosis of acute type A aortic dissection.MethodsA total of 361 patients who underwent type A aortic dissection surgery in Fujian Cardiac Medical Center from June 2018 to March 2020 were retrospectively collected. According to the baseline TG/HDL-C ratio, the patients were divided into 3 groups according to the tertile method, the low TG/HDL-C ratio T1 group (< 1.18) and the middle TG/HDL-C ratio T2 group (1.18–1.70). T3 group with high TG/HDL-C ratio (> 1.70). Kaplan–Meier was used for survival analysis, and Cox proportional hazards regression model was used to analyze the factors affecting the prognosis of patients. The receiver operating characteristic (ROC) curve was used for the diagnostic efficacy.ResultsAmong the 361 patients in this study, the mean age was 52.4 ± 11.3 years, 73 (20.2%) were female, and 82 (22.7%) died in hospital. Kaplan–Meier curve showed that with the increase of TG/HDL-C ratio, the risk of in-hospital death gradually increased (P < 0.001). Multivariate Cox regression analysis showed that age (HR = 1.031), body mass index (HR = 1.052), hypertension (HR = 3.491), white blood cells (HR = 1.073), TG/HDL-C ratio (HR = 1.604), MODS (HR = 1.652) was positively correlated with in-hospital mortality (P < 0.05). After adjusting for age, sex, and other risk factors, a significant association was found between the TG/HDL-C ratio and in-hospital mortality for acute type A aortic dissection (HR = 1.472, 95% CI, 1.354–3.451, P = 0.019).ConclusionPatients with type A aortic dissection have obvious abnormal blood lipid metabolism, and serum TG/HDL-C levels are positively correlated with in-hospital mortality in patients with AAAD.

Early dynamic behavior of lactate in predicting continuous renal replacement therapy after surgery for acute type A aortic dissection.

BackgroundIt has been well known that hyperlactatemia is an independent risk factor for postoperative mortality in patients who received acute type A aortic dissection (ATAAD) surgery. Some patients may require the assistance of continuous renal replacement therapy (CRRT) for acute postoperative renal deficiency and often associate with increased mortality rate. This study aimed to examine the association between the early dynamic change of lactate levels and postoperative CRRT in ATAAD patients who received surgical repairment.MethodsThis retrospective study included 503 patients who received ATAAD surgeries. Serum lactate levels were measured before operation and at 0, 1, 3, 6, 12, 24 h post intensive care unit (ICU) admission. We examined the association between dynamic changes of lactate and CRRT.ResultsAmong all patients, 19.9% (100 patients) required CRRT. Our data showed that the lactate levels were higher in the CRRT group at all timepoints compared to the non-CRRT group. In a multivariate model, lactate levels at 12 h post ICU admission [odds ratio (OR), 1.362; p = 0.007] was identified as an independent predictor for requiring CRRT. Unsurprisingly, 30-day mortality in the CRRT group (41%) was 8.2 times higher than in the non-CRRT group (5%). To better understand the associations between CRRT and lactate levels, patients in the CRRT group were further stratified into the non-survivor group (n = 41) and survivor group (n = 59) based on the 30-day mortality. Elevated lactate levels measured upon ICU admission (OR, 1.284; p = 0.001) and decreased 24 h lactate clearance (OR, 0.237; p = 0.039) were independent risk factors for 30-day mortality in patients who received CRRT. The area under the curve to predict requirement for CRRT at 6 and 12 h post CICU admission were 0.714 and 0.722, respectively, corresponding to lactate cut-off levels of 4.15 and 2.45 mmol/L.ConclusionThe CRRT is commonly required in patients who received ATAAD surgery and often associated with worse mortality. Early dynamic changes of lactate levels can be used to predict the requirement of postoperative CRRT.

Risk factors in the development of postoperative complications after reconstructive surgery on the thoracic aorta.

Aim To determine risk factors responsible for developing postoperative complications after the thoracic aorta reconstructive surgery. Methods Medical records of 100 patients, who had undergone elective or emergency thoracic aorta reconstructive surgery at the Clinic for Cardiovascular Surgery, University Clinical Center Tuzla, were analysed. Intraoperative data as cross-clamp time (CCT), duration of cardiopulmonary bypass (CPBT) and hypothermic circulatory arrest time (HCAT) were evaluated. Univariate analysis was used to show risk factors for developing postoperative cardiac, respiratory, surgical and renal complications. Results Between May 2019 and April 2021, 48 Bentall procedures (BP), 23 ascending aortic replacements (AAR), 20 BP and coronary artery bypass grafting (CABG) and 9 aortic valve replacements (AVR) with AAR were performed. Incidence of postoperative complications in the elective and emergency groups was as follows: respiratory 20% vs 38% (p=0.049), cardiac 18% vs 70% (p=0.015), renal 16% vs 48% (p=0.027) and surgical 4% vs 6% (p>0.05). Intrahospital 30 days morbidity was 44% with mortality rate of 13%. The results showed that CPBT>180 minutes was a risk factor for respiratory (p=0.034), cardiac (p=0.020) and renal (p=0.027) postoperative complications after acute type A aortic dissection surgery. Conclusion CPBT > 180 min is a risk factor for postoperative development of respiratory, cardiac and renal complications. Postoperative cardiac and renal complications were associated with longer HCAT.

Long-term results of bare metal stents and frozen elephant trunk prosthesis using in aortic dissection surgery

Aim. Comparative assessment of long-term results of bare metal stents and frozen elephant trunk prosthesis using in aortic dissection I DeBakey type.Methods. The retrospective comparative evaluation of different surgery results (2001–2017) in 213 patients with DeBakey type I aortic dissection was performed. Patients was divided in to 3 groups: Group 1 — standard treatment (hemiarch or total arch replacement) (n = 121), Group 2 — arch reconstruction with bare metal stent (n = 55), Group 3 — arch reconstruction with frozen elephant trunk prosthesis (n = 37). For groups equation we used propensity score matching analysis (PSM).Results. A pairwise comparison with the formation of three groups equated by the PSM method was performed. Long-term mortality in PSM 1 was 88 [82; 96] % (Group 1) и 89 [79; 100] % — (Group 2) respectively (p = 0.893). Long-term mortality in PSM 2 was 85 [71; 100] % in Group 1 and 94 [84; 100] % — Group 3 respectively (p = 0.342). Long-term mortality in PSM 3 was 88 [77; 100] % in Group 2 и 80 [64; 100] % — Group 3 respectively (p = 0.457). Freedom from aortic and mortality events (surrogate end point) in PSM 1 was 68% and 75% (p&gt;0.999), PSM 2 was 50% and 100% (p = 0.006), PSM 3 was 73% and 89% (p = 0.22).Conclusion. There were no any statistical differences in long-term mortality and in surrogate end point (aortic events and mortality) between groups, but there was a trend to better results in Group 3.

Preliminary evaluation of the Chinese version of the patient-reported outcomes measurement information system 29-item profile in patients with aortic dissection

BackgroundThe Patient-Reported Outcomes Measurement Information System 29-item Profile (PROMIS-29) has been widely used to measure health outcomes from the patient’s perspective. It has not been validated in adults with aortic disease. The aim of this study was to explore the reliability and validity of the Chinese PROMIS-29 among patients undergoing surgery for aortic dissection (AD).MethodsA cross-sectional design was applied. Eligible patients completed a questionnaire that contained the PROMIS-29 and legacy measures, including the Short Form-12 Health Survey (SF-12), 8-item Somatic Symptom Scale (SSS-8), Generalized Anxiety Disorder–2 (GAD-2), and Patient Health Questionnaire-2 (PHQ-2). The structural validity of the PROMIS-29 was evaluated using confirmatory factor analysis (CFA). Reliability was evaluated with Cronbach’s α. Construct validity was assessed by calculating Spearman’s rank correlations and comparing known-group differences.ResultsIn total, a sample of 327 AD patients was included in the final analysis. Most of them were male (89%) with a mean age of 52.7 (± 10.3). CFA revealed good model fit of the seven-factor structure within PROMIS-29, as well as most domains in single-factor analysis. Reliability was confirmed with Cronbach’s α > 0.90. Correlations between comparable domains of the PROMIS-29 and those of legacy questionnaires and most know-group comparisons were observed as hypothesized.ConclusionsThis study found evidence for acceptable structural validity, construct validity and internal consistency of the PROMIS-29 in a sample of AD patients. It can be applied to AD survivors by researchers or clinicians, measuring outcomes after surgery and identifying those with worse health status.

The impact of age and sex on in-hospital outcomes in acute type A aortic dissection surgery.

BackgroundOlder age and female sex are thought to be risk factors for adverse outcomes after repair of acute type A aortic dissection (AAAD). The aim of this study is to analyze age- and sex-related outcomes in patients undergoing AAAD repair.MethodsRetrospective analysis of patients undergoing emergency AAAD repair. Patients were divided in Group A, patients aged ≥75 years and Group B <75. Intraoperative and postoperative data were compared between groups before and after propensity score matching. Sex differences were analyzed by age group.ResultsBetween January 2006 and December 2018, 638 patients underwent emergency AAAD repair. Group A included 143 patients (22.4%), Group B 495 (77.6%). More patients in Group A presented with circulatory collapse (Penn C 26.6% vs. 9.7%, P=0.001) while Group B presented with circulatory collapse-branch malperfusion (Penn BC 29.3% vs. 15.4% P=0.001). After propensity score matching, Group B patients received more complex aortic root (33.6% vs. 23.2%, P=0.019) and concomitant bypass surgery (12.3% vs. 6.3%, P=0.042). There was no significant difference in in-hospital mortality between age groups (18% vs. 12% P=0.12). In Group B, in-hospital mortality was significantly higher in females (22.2% vs. 8.2%, P=0.028). Differences in mortality disappeared after the age of 75 (18.3% vs. 19.4% P=0.87).ConclusionsMorbidity and mortality are comparable between patients under and over 75 years after AAAD repair. Female patients <75 had higher in-hospital mortality than their male counterparts.

Is Exercise Blood Pressure Putting the Brake on Exercise Rehabilitation after Acute Type A Aortic Dissection Surgery?

(1) Background: Exercise is recommended to improve physical fitness in patients recovering from acute type A aortic dissection (ATAAD). However, surgery corrects the diseased blood vessels and reduces the risk of ATAAD, but it does not redefine a safe exercise blood pressure (BP) threshold. This review aimed to discuss whether the safe threshold of exercise BP can be upregulated after ATAAD surgery to increase exercise intensity with additional benefits. (2) Data sources: The PubMed databases were searched with the keywords “type A acute aortic dissection surgery”, “exercise”, “BP”, “stress”, and variations of these terms. (3) Study selection: Data from clinical trials, guidelines, and recent reviews were selected for review. (4) Results: Regular exercise can be considered a cardioprotective intervention for aortic dissection patients by attenuating hemodynamic responses at rest and during exercise. Previous studies have mainly focused on moderate-intensity aerobic exercise. In practice, the exercise systolic BP of some patients was higher than 160 mm Hg without adverse events, which indicates that the training intensity may be underestimated for patients after ATAAD surgery. Limited studies suggest a light-to-moderate resistance training for selected patients because it may cause a greater increase in BP. (5) Conclusions: Moderate-intensity continuous aerobic exercise supplemented by low-intensity resistance training is appropriate for cardiac rehabilitation after ATAAD surgery. The BP increase based on the normal exercise BP response, corresponding to the moderate-intensity is relatively safe. For high-risk post-ATAAD patients, considering the overall volume of training, personalizing the exercise regimen to remain within “safe” BP limits, and avoiding excessive fluctuations in BP should be the primary considerations for exercise training.

The orthostatic hypotension in patients with Stanford type A aortic dissection after surgery

Abstract Funding Acknowledgements Type of funding sources: None. Background Orthostatic hypotension (OH) is sometimes observed during cardiac rehabilitation in patients with surgery for aortic dissection. However, little is known about the primary determinant of OH and influence of surgical range on incidence of OH. Purpose The aim of this study was to elucidate the incidence of OH in patients with surgery for aortic dissection, and compare it between the patients with ascending aortic replacement surgery (ascending group) and those with ascending aorta and hemiarch or total arch replacement surgery (arch group). Methods We analyzed 59 patients who underwent emergent surgery due to Stanford type A aortic dissection from January 2014 to March 2018, and compared the incidence of OH between ascending group (n = 28, age 69.8 ± 11.3 years) and arch group (n = 31, age 64.1 ± 13.0 years). Results The incidence of OH in total patients was 30.5%. There were no significant differences in patient characteristics including body tall, body weight, antihypertensive use and progress of rehabilitation between 2 groups. The arch group showed a significant higher incidence of OH as compared with ascending group (arch group: 46.4% vs. ascending group: 16.1%, p = 0.03). Moreover, the patients who occurred OH were significantly taller than those who did not occur OH. Conclusions OH was observed in about one third of patients with surgery for aortic dissection and it showed a close relationship with patient’s height and the range repaired by surgical operation. More careful cardiac rehabilitation is needed for tall patients with large area replacement of aorta.

Intraoperative nadir hematocrit as a poor outcome predictor after acute type A aortic dissection surgey.

Acute type A aortic dissection is a life-threatening disease associated with high morbidity and mortality that requires urgent surgical intervention. Hemodilution is inevitable in cardiac operations performed with cardiopulmonary bypass, which leads to nadir hematocrit levels. Studies have shown that nadir hematocrit levels are associated with poor postoperative outcomes. The management strategy of intraoperative anemia in these operations is still controversial. Should we follow the patients with intraoperative low hematocrit values or should we transfuse them? In addition to intraoperative nadir hematocrit, cannulation strategies play an important role in early postoperative outcomes after aortic dissection surgery.

Prognosis factors for death within 90 days of discharge in patients with acute kidney injury requiring continuous renal replacement therapy after surgery for Stanford type A acute aortic dissection

Objective: To investigate the prognosis factors for death within 90 days after discharge in patients with acute kidney injury(AKI) treated requiring continuous renal replacement therapy(CRRT) undergoing surgery for acute Standford type A aortic dissection. Methods: The clinic data of 126 patients undergoing CRRT for postoperative AKI after acute type A aortic dissection surgery in the Center for Cardiac Intensive Care, Beijing Anzhen Hospital from July 2016 to February 2019 were analyzed retrospectively. There were 83 males and 43 females, aging (52.9±11.2) years(range: 25 to 70 years). The patients' demographic characteristics, disease-related information, perioperative data, laboratory indexes during CRRT, complications, and survival information within 90 days after discharge were recorded. Independent prognosis factors for death within 90 days of discharge were determined by Kaplan-Meier survival analysis, univariate and multifactorial Cox regression analysis. Results: Totally 57 of 126 patients(45.2%) died over the first 90 days after discharge. Kaplan-Meier survival analysis and univariate Cox regression analysis showed that there were significant differences between the non-survival and survival group including ≥65 years old, high lactate values 12 hours after CRRT, pulmonary infection, liver dysfunction, presence of permanent neurological complications, and postoperative ejection fraction(EF)<45%. Multifactorial Cox regression analysis revealed that ≥65 years old(HR=2.14, 95%CI: 1.09 to 4.21, P=0.03), high lactate values 12 hours after CRRT(HR=1.13, 95%CI: 1.06 to 1.20, P=0.01) and postoperative EF<45%(HR=2.21, 95%CI: 1.09 to 4.51, P=0.03) were independent prognosis factors for patients' death within 90 days after hospital discharge. Conclusions: ≥65 years old, high lactate values 12 hours after CRRT and postoperative EF<45% are independent prognosis factors for death within 90 days after discharge in patients undergoing CRRT for AKI after acute type A aortic dissection surgery. Proper identification and management of prognosis factors could be beneficial to improve patients' outcomes.

Preoperative Nomogram and Risk Calculator for Postoperative Hypoxemia and Related Clinical Outcomes Following Stanford Type A Acute Aortic Dissection Surgery.

BackgroundHypoxemia is a common complication after Stanford type A acute aortic dissection surgery (AADS), however, few studies about hypoxemia after AADS exist. The aims of this study were to identify independent risk factors for hypoxemia after AADS and to clarify its association with clinical outcomes.MethodsPatients undergoing AADS from 2016 to 2019 in our hospital were identified and used as a training set. Preoperative variables were first screened by univariate analysis and then entered into a multivariate logistic regression analysis to identify independent risk factors. A nomogram and an online risk calculator were constructed based on the logistic model to facilitate clinical practice and was externally validated in an independent dataset.ResultsSevere hypoxemia developed in 119 of the 492 included patients (24.2%) and poorer clinical outcomes were observed in these patients. Five independent risk factors for severe hypoxemia after AADS were identified by multivariate analysis, including older age, smoking history, renal insufficiency, higher body mass index, and white blood cell count. The model showed good calibration, discrimination, and clinical utility in the training set, and was well validated in the validation set. Risk stratification was performed and three risk groups were defined as low, medium, and high risk groups. Hypertension was identified as an independent risk factor for moderate hypoxemia besides the five predictors mentioned above, and renal insufficiency was not significant for mild hypoxemia by multivariate analysis. In addition, although frozen elephant trunk was associated with increased risk of postoperative hypoxemia in the univariate analysis, frozen elephant trunk was also not identified as an independent risk factor for postoperative hypoxemia in the multivariate analysis.ConclusionHypoxemia was frequent following AADS, related to poorer clinical outcomes. Predictors were identified and a nomogram as well as an online risk calculator predicting severe hypoxemia after AADS was developed and validated, which may be helpful for risk estimation and perioperative management.

Prone Position in Treatment of Hypoxemia in Patients Who Underwent Type A Aortic Dissection Surgery.

Postoperative hypoxemia is a high-risk complication after acute type A aortic dissection (TAAD) surgery. Prone position (PP) is an effective treatment for acute respiratory failure, which may improve the gas exchange of the injured lung and the patient's survival. PP is reported to improve the respiratory condition after cardiac surgery. However, limited data exist on the effect of PP in patients who underwent acute TAAD surgery. We retrospectively analyzed the clinical outcomes of seven patients with severe hypoxemia who underwent PP after acute TAAD surgery. The results of arterial blood gas, chest X-ray, and survival were collected. Seven patients (3 female, mean age 48.3±11.7 years) were recruited in this study. All patients received total arch replacement and frozen elephant trunk implantation procedure. The PaO2 at day 1 after PP was higher than before PP (126.3±49.3 vs. 77.8±15.5 mmHg). The oxygenation index rose sharply from 83.0 (80.0, 87.0) to 188.3±56.5 at day 3 after PP. There was no significant difference in heart rate between before and after PP procedure. Chest X-ray showed the diffuse shadow was significantly improved after PP. All patients responded well to PP, and all patients were discharged except for one patient, who died perioperatively due to multiple organ failure. PP is a safe and feasible option for severe hypoxemia patients after TAAD surgery.

False lumen thrombus following aortic dissection diagnosed as the source of repeat lower extremity emboli with angioscopy: a case report

BackgroundAcute arterial embolization caused by a free-floating thrombus of the false lumen after surgery for acute aortic dissection is a rare complication; hence, determining its cause may be difficult. We report a case in which angioscopy was valuable in diagnosing and treating the unstable thrombus within the false lumen.Case presentationThe patient was a 71-year-old woman who underwent hemiarch replacement for Stanford type A acute aortic dissection. Two months after the operation, left renal infarction occurred. Eighteen months after the operation, the patient visited the hospital for treatment of intermittent claudication of her left leg. Computed tomography (CT) showed occlusion below the left common femoral artery. Surgical thrombectomy was performed for acute lower extremity arterial occlusion. One month later, thrombectomy was performed again for the same phenomenon and again after 2 months. She had no history of cardiac arrhythmia. No obvious source for the repeat embolization could be found on echocardiography or enhanced CT. Angiography was performed to further identify the cause, revealing a new entry site at the distal anastomosis, which exhibited antegrade flow into the false lumen. Furthermore, selective false lumen angiography via the re-entry revealed a thrombus in the false lumen corresponding to the descending aorta. A non-obstructive angioscopy system in the false lumen revealed a free-floating thrombus. As the patient had undergone multiple surgeries over a short period and desired minimally invasive treatment, coil embolization of the new entry site as well as false lumen was performed. As a result, blood flow from the true to the false lumen resolved. More than 1 year has passed following coil embolization with no signs of embolism.ConclusionsWe experienced a case of repeat embolism caused by unstable thrombus formation in the false lumen resulting from antegrade blood flow in the false lumen secondary to development of a new entry site. Angioscopy revealed that this antegrade flow caused formation of an unstable thrombus which caused recurrent acute lower extremity arterial occlusion. Therefore, angioscopy may be a useful option for the diagnosis of false lumen thrombosis.

Prediction model for postoperative severe acute lung injury in patients undergoing acute type A aortic dissection surgery.

This study aimed to establish a risk assessment model to predict postoperative severe acute lung injury (ALI) risk in patients with acute type A aortic dissection (ATAAD). Consecutive patients with ATAAD admitted to our hospital were included in this retrospective assessment and placed in the postoperative severe ALI and nonsevere ALI groups based on the presence or absence of ALI within 72 h postoperatively (oxygen index [OI] ≤ 100 mmHg). Patients were then randomly divided into training and validation groups in a ratio of 8:2. Univariate and multivariate stepwise forward logistic regression analyses were used to statistically assess data and establish the prediction model. The prediction model's effectiveness was evaluated via 10-fold cross-validation of the validation group to facilitate the construction of a nomogram. After the screening, 479 patients were included in the study: 132 (27.6%) in the postoperative severe ALI group and 347 (72.4%) in the postoperative nonsevere ALI group. Based on multivariate logistics regression analyses, the following variables were included in the model: coronary heart disease, cardiopulmonary bypass (CPB) ≥ 257.5 min, left atrium diameter ≥ 35.5 mm, hemoglobin ≤ 139.5 g/L, preCPB OI ≤ 100 mmHg, intensive care unit OI ≤ 100 mmHg, left ventricular posterior wall thickness ≥ 10.5 mm, and neutrophilic granulocyte percentage ≥ 0.824. The area under the receiver operating characteristic (ROC) curve of the modeling group was 0.805 and differences between observed and predicted values were not deemed statistically significant via the Hosmer-Lemeshow test (χ2 = 6.037, df = 8, p = .643). For the validation group, the area under the ROC curve was 0.778, and observed and predicted value differences were insignificant when assessed using the Hosmer-Lemeshow test (χ2 = 3.3782, df = 7; p = .848). The average 10-fold cross-validation score was 0.756. This study established a prediction model and developed a nomogram to determine the risk of postoperative severe ALI after ATAAD. Variables used in the model were easy to obtain clinically and the effectiveness of the model was good.

Unsolved issues in acute type A aortic dissection.

Surgery for acute type A aortic dissection remains challenging with considerable mortality and morbidity despite the remarkable advances in this field. Particularly, surgical outcomes of acute type A aortic dissection are known to be associated with the hospital volume. The optimal cerebral protective method and extent of surgery have been long-standing controversies in acute type A aortic dissection surgery. Given that data from randomized trial are not available and future trials are also unrealistic, observational data based on large registry or meta-analyses may alternatively provide reliable and reasonable evidence. With regard to neuroprotective methods for arch repair, currently available observational data strongly suggest that there are no overt superiority among unilateral-antegrade cerebral perfusion, bilateral-antegrade cerebral perfusion, and retrograde cerebral perfusion, by which their availabilities are still open in real clinical practices depending on institutional preferences. When deciding the extent of arch repair in acute DeBakey type I aortic dissection, multiple factors should be considered altogether such as aortic anatomic characteristics as well as patient's risk profiles for optimizing early safety and late aortic longevity.

Predictors and outcomes of postoperative tracheostomy in patients undergoing acute type A aortic dissection surgery

BackgroundDespite surgical advances, acute type A aortic dissection remains a life-threatening disease with high mortality and morbidity. Tracheostomy is usually used for patients who need prolonged mechanical ventilation in the intensive care unit (ICU). However, data on the risk factors for requiring tracheostomy and the impact of tracheostomy on outcomes in patients after Stanford type A acute aortic dissection surgery (AADS) are limited.MethodsA retrospective single-institutional study including consecutive patients who underwent AADS between January 2016 and December 2019 was conducted. Patients who died intraoperatively were excluded. Univariate analysis and multivariate logistic regression analysis were used to identify independent risk factors for postoperative tracheostomy (POT). A nomogram to predict the probability of POT was constructed based on independent predictors and their beta-coefficients. The area under the receiver operating characteristic curve (AUC) was performed to assess the discrimination of the model. Calibration plots and the Hosmer–Lemeshow test were used to evaluate calibration. Clinical usefulness of the nomogram was assessed by decision curve analysis. Propensity score matching analysis was used to analyze the correlation between requiring tracheostomy and clinical prognosis.ResultsThere were 492 patients included in this study for analysis, including 55 patients (11.2%) requiring tracheostomy after AADS. Compared with patients without POT, patients with POT experienced longer ICU and hospital stay and higher mortality. Age, cerebrovascular disease history, preoperative white blood cell (WBC) count and renal insufficiency, intraoperative amount of red blood cell (RBC) transfusion and platelet transfusion were identified as independent risk factors for POT. Our constructed nomogram had good discrimination with an AUC = 0.793 (0.729–0.856). Good calibration and clinical utility were observed through the calibration and decision curves, respectively. For better clinical application, we defined four intervals that stratified patients from very low to high risk for occurrence of POT.ConclusionsOur study identified preoperative and intraoperative risk factors for POT and found that requiring tracheostomy was related to the poor outcomes in patients undergoing AADS. The established prediction model was validated with well predictive performance and clinical utility, and it may be useful for individual risk assessment and early clinical decision-making to reduce the incidence of tracheostomy.