Malperfusion in Acute Type A Aortic Dissection: Management Strategies

AKI-Pro score for predicting progression to severe acute kidney injury or death in patients with early acute kidney injury after cardiac surgery

BACKGROUND

No reliable clinical tools exist to predict acute kidney injury (AKI) progression. We aim to explore a scoring system for predicting the composite outcome of progression to severe AKI or death within seven days among early AKI patients after cardiac surgery.

METHODS

In this study, we used two independent cohorts, and patients who experienced mild/moderate AKI within 48 h after cardiac surgery were enrolled. Eventually, 3188 patients from the MIMIC-IV database were used as the derivation cohort, while 499 patients from the Zhongshan cohort were used as external validation. The primary outcome was defined by the composite outcome of progression to severe AKI or death within seven days after enrollment. The variables identified by LASSO regression analysis were entered into logistic regression models and were used to construct the risk score.

RESULTS

The composite outcome accounted for 3.7% (n = 119) and 7.6% (n = 38) of the derivation and validation cohorts, respectively. Six predictors were assembled into a risk score (AKI-Pro score), including female, baseline eGFR, aortic surgery, modified furosemide responsiveness index (mFRI), SOFA, and AKI stage. And we stratified the risk score into four groups: low, moderate, high, and very high risk. The risk score displayed satisfied predictive discrimination and calibration in the derivation and validation cohort. The AKI-Pro score discriminated the composite outcome better than CRATE score, Cleveland score, AKICS score, Simplified renal index, and SRI risk score (all P < 0.05).

CONCLUSIONS

The AKI-Pro score is a new clinical tool that could assist clinicians to identify early AKI patients at high risk for AKI progression or death.

Surgical choice for the treatment of partial intestinal ischemic necrosis caused by acute type a aortic dissection combined with malperfusion of superior mesenteric artery

Acute type A aortic dissection is a severe cardiovascular disease characterized by rapid onset and high mortality. Traditionally, urgent open aortic repair is performed after admission to prevent aortic rupture and death. However, when combined with malperfusion syndrome, the low perfusion of the superior mesenteric artery can further lead to intestinal necrosis, significantly impacting the surgery's prognosis and potentially resulting in adverse consequences, bringing. This presents great significant challenges in treatment. Based on recent domestic and international research literature, this paper reviews the mechanism, current treatment approaches, and selection of surgical methods for poor organ perfusion caused by acute type A aortic dissection. The literature review findings suggest that central aortic repair can be employed for the treatment of acute type A aortic dissection with inadequate perfusion of the superior mesenteric artery. The superior mesenteric artery can be windowed and (/or) stented, followed by delayed aortic repair. Priority should be given to revascularization of the superior mesenteric artery, followed by central aortic repair. During central aortic repair, direct blood perfusion should be performed on the distal true lumen of the superior mesenteric artery, leading to resulting in favorable therapeutic outcomes. The research results indicate that even after surgical aortic repair, intestinal ischemic necrosis may still occur. In such cases, prompt laparotomy and necessary necrotic bowel resection are crucial for saving the patient's life.

Teduglutide-induced acute gastric mucosal necrosis in short bowel syndrome with hepatorenal failure: Case report

INTRODUCTION

Short bowel syndrome (SBS) resulting from acute aortic dissection (AAD)-induced visceral malperfusions leads to chronic intestinal failure (CIF), necessitating patients to adopt home parenteral nutrition to prevent malabsorption. Teduglutide (TED), a glucagon-like peptide-2 analog, is a promising pharmacotherapy for intestinal rehabilitation that reduces parenteral support and improves the quality of life. Gastric mucosal necrosis, a rare gastrointestinal disorder, had never been observed as an adverse event relevant to this drug. We report a case of mucosal necrosis in the stomach after TED treatment for SBS-CIF with hepatorenal failure.

PRESENTATION OF CASE

A 68-year-old Japanese man who underwent massive intestinal resection for AAD experienced malnutrition and diarrhea caused by SBS-CIF. The patient received TED to improve intestinal absorption and entero-hepatic circulation besides controlling infectious diseases. Endoscopy showed mucosal hyperplasia in the stomach and duodenum 1.5 months after TED administration. The patient consented to enteral nutrition via a nasogastric tube because of anorexia. The nutritional status gradually improved after initiating enteral feeding. However, the patient experienced hematemesis 13 days after enteral feeding, and endoscopy revealed acute gastric mucosal necrosis, followed by fatal septic shock.

DISCUSSION

For patients with SBS, TED is expected to increase intestinal absorption through epithelial proliferation. When SBS is accompanied by multiple ischemic organ failure, TED therapeutic effects remain unclear as malnutrition-associated infectious diseases are refractory, and many underlying mechanisms can be involved.

CONCLUSION

TED administration should be deliberately considered for patients with SBS-CIF and multiple organ failure experiencing uncontrolled systemic infection.

Development and validation of a prediction model for postoperative ischemic stroke following total arch replacement and frozen elephant trunk under mild hypothermia

Background

Early identification of postoperative ischemic stroke among patients with acute DeBakey type I aortic dissection (ADIAD) is of great significance to taking timely effective treatment. We aimed to develop and validate a prediction model for postoperative ischemic stroke in ADIAD patients who underwent total arch replacement (TAR) and frozen elephant trunk (FET) under mild hypothermia.

Methods

ADIAD patients who underwent TAR and FET between January 2017 and April 2023 were enrolled in our study. Preoperative and intraoperative variables were selected using pairwise comparisons, the Least Absolute Shrinkage and Selection Operator (LASSO), and logistic regression to construct a prediction model for postoperative ischemic stroke. The accuracy and calibration of the model were assessed using 1000 bootstrap resamples for internal validation, with the area under the receiver operating characteristic curve (AUC) and the Hosmer-Lemeshow test. The AUC was also used to evaluate the model's accuracy in the validation cohort.

Results

The development cohort included 246 patients. The mean [standard deviation (SD)] age of patients in the cohort was 50.7 (11.2) years, 196 (79.7%) were men, and 22 (8.9%) were diagnosed with postoperative ischemic stroke. The validation cohort included 73 patients with a mean (SD) age of 52.5 (11.9) years, 58 (79.5%) were men and 3 (4.1%) were diagnosed with postoperative ischemic stroke. Three variables out of the initial 40 potential predictors were included in the final prediction model: the platelet count [odd ratio (OR), 0.992; 95% confidence interval (CI), 0.983-1.000], the presence of innominate artery dissection (OR, 3.400; 95% CI, 1.027-11.260), and the flow of selective cerebral perfusion (OR, 0.147; 95% CI, 0.046-0.469). The mean AUC in the development cohort was 0.77 (95% CI, 0.68-0.87), and calibration was checked with the Hosmer-Lemeshow test (P = 0.78). In the validation cohort, the AUC was 0.98 (95% CI, 0.94-1.00). A prediction model and a clinical impact curve were developed for practical purposes.

Conclusions

In this study, we have developed a prediction model with competent discriminative ability and calibration. This model can be used for early assessment of the risk of postoperative ischemic stroke in patients with ADIAD following TAR and FET under mild hypothermia.

Outcomes of two-stage type II hybrid aortic arch repair in elderly patients with acute type A aortic dissection

Acute type A aortic dissection (a-TAAD) is a severe disease characterized by high mortality, which can be fatal in elderly patients. The objective of this study was to investigate the safety and efficacy of two-stage type II hybrid aortic arch repair (HAR) in elderly patients with acute type A aortic dissection (a-TAAD). This was a single-center, retrospective study involving 119 patients with a-TAAD, including 82 males and 37 females, aged 22-81 years old. Eighty-eight patients underwent total aortic arch replacement (TAR) with frozen elephant trunk (FET) implantation (TAR with FET group) and 31 patients underwent two-stage type II HAR (HAR group). Propensity score matching was applied to adjust for preoperative data, and match 25 pairs. The preoperative, perioperative, postoperative and follow-up data were recorded. Fifteen patients died during the perioperative period; 13 cases were in the TAR with FET group and 2 cases were in the HAR group. The age, body mass index, cerebral infarction, renal insufficiency were significantly higher, and the 24-h fluid drainage, the incidence of acute liver injury, acute kidney injury and pulmonary infection were lower in the HAR group (all P < 0.05). Moreover, the mechanical ventilation time, intensive care unit time, hospital stay time were shorter in the HAR group (all P < 0.05). The follow-up period ranged from 12 to 54 months, with 7 deaths (9.3%) in the TAR with FET group and 2 deaths (6.9%) in the HAR group. The true lumen of the aortic arch and the middle descending thoracic aorta were larger and the false lumen thrombosis rates of the middle descending thoracic aorta and renal artery level were higher in the HAR group (all P < 0.05). Two-stage type II HAR is a safe and effective method for the treatment of elderly patients with a-TAAD. It may be a good choice for elderly patients with a-TAAD and comorbidities.

Optimized strategy to improve the outcomes of acute type A aortic dissection with malperfusion syndrome

BACKGROUND

The mortality of acute type A aortic dissection (ATAAD) with malperfusion syndrome (MPS) is high. However, the management strategy remains controversial. We aimed to evaluate the strategy for MPS at our institution.

METHODS

Among 724 patients with ATAAD, 167 patients with MPS were treated with immediate central repair (first stage) or an optimized strategy (second stage). In the second stage, the optimized strategy used was based on 6-hour threshold from symptom onset. For MPS with symptom onset within 6 hours, immediate central repair was performed, followed by endovascular reperfusion if malperfusion persisted. With symptom onset beyond 6 hours, individualized delayed central repair was performed. We compared outcomes between the first and second stages.

RESULTS

The in-hospital mortality of ATAAD was significantly decreased when the optimized strategy was used (4.3% in the second stage vs 12.5% in the first stage; P < .01). In the second stage, the in-hospital mortality for MPS was decreased (10.2% vs 33.9%; P < .01). Moreover, the in-hospital mortality for MPS with symptom onset within 6 hours and beyond 6 hours decreased from 24% to 7.5% and from 41.2% to 11.8%, respectively. The operative mortality of MPS in the second stage was comparable to that in patients without MPS (4.0% vs 2.4%; P > .05).

CONCLUSIONS

The optimized strategy significantly improved the outcomes of MPS. The 6-hour threshold from symptom onset could be very useful in determining the timing of central repair. For patients with MPS symptom onset within 6 hours, immediate central repair is reasonable; for those with symptom onset beyond 6 hours, individualized delayed central repair should be considered.

Preoperative Imaging Signs of Cerebral Malperfusion in Acute Type A Aortic Dissection: Influence on Outcomes and Prognostic Implications-A 20-Year Experience

BACKGROUND

Acute type A aortic dissection (ATAAD) continues to be a subject of active research due to its high mortality rates and associated complications. Cerebral malperfusion in ATAAD can have a devastating impact on patients' neurological function and overall quality of life. We aimed to explore the risk profile and prognosis in ATAAD patients presenting with preoperative imaging signs of cerebral malperfusion (PSCM).

METHODS

We obtained patient data from our Aortic Dissection Registry, which included 480 consecutive ATAAD cases who underwent surgical repair between 2001 and 2021. Primary endpoint outcomes included the in-hospital and 30-day mortality, postoperative new neurological deficit, mechanical ventilation hours, and intensive care unit (ICU) length of stay.

RESULTS

Of the total cohort, 82 patients (17.1%) had PSCM. Both groups had similar distributions in terms of age, sex, and body mass index. The patients in the PSCM group presented with a higher logistic EuroSCORE (47, IQR [31, 64] vs. 24, IQR [15, 39]; p < 0.001) and a higher portion of patients with a previous cardiac surgery (7.3% vs. 2.0%; p = 0.020). Intraoperatively, the bypass, cardioplegia, and aortic cross-clamp times were similar between both groups. However, the patients in the PSCM group received significantly more intraoperative packed red blood cells, fresh frozen plasma, and platelets transfusions (p < 0.05). Following the surgery, the patients who presented with PSCM had markedly longer ventilation hours (108.5 h, IQR [44, 277] vs. 43 h, IQR [16, 158], p < 0.001) and a significantly longer ICU length of stay (7 days, IQR [4, 13] vs. 5 days, IQR [2, 11]; p = 0.013). Additionally, the patients with PSCM had significantly higher rates of postoperative new neurological deficits (35.4% vs. 19.4%; p = 0.002). In the Cox regression analysis, PSCM was associated with significantly poorer long-term survival (hazard ratio (HR) 1.75, 95%CI [1.20-2.53], p = 0.003). Surprisingly, hypertension was shown as a protective factor against long-term mortality (HR: 0.59, 95%CI [0.43-0.82], p = 0.001).

CONCLUSION

PSCM in ATAAD patients is linked to worse postoperative outcomes and poorer long-term survival, emphasizing the need for early recognition and tailored management.

Lower-extremity malperfusion syndrome in patients undergoing proximal aortic surgery for acute type A aortic dissection

Objective

Data regarding management of lower-extremity malperfusion in the setting of type A aortic dissection are limited. This study aimed to compare acute type A aortic dissection with lower-extremity malperfusion outcomes in patients undergoing lower-extremity revascularization with no revascularization.

Methods

Consecutive patients undergoing acute type A aortic dissection surgery were identified from a prospectively maintained database. Perioperative variables were compared between patients with and without lower-extremity malperfusion. Factors associated with lower-extremity malperfusion, revascularization, and mortality were determined using univariable Cox regression and Firth's penalized likelihood modeling.

Results

From January 2007 to December 2021, 601 patients underwent proximal aortic repair for acute type A aortic dissection at a quaternary care center. Of these, 85 of 601 patients (14%) presented with lower-extremity malperfusion and were more often male (P = .02), had concomitant moderate or greater aortic insufficiency (P = .05), had lower ejection fraction (P = .004), had preoperative dialysis dependence (P = .01), and had additional cerebral, visceral, and renal malperfusion syndromes (P < .001). Kaplan-Meier estimated survival fared worse with lower-extremity malperfusion compared with no lower-extremity malperfusion at 1, 5, and 10 years (84% vs 77%, 74% vs 71%, 65% vs 52%, respectively, P = .03). In the lower-extremity malperfusion group, 15 of 85 patients (18%) underwent lower-extremity revascularization without significant differences in postoperative morbidity and mortality compared with patients not undergoing revascularization. Need for peripheral revascularization was associated with peripheral vascular disease (hazard ratio, 3.7 [1.0-14.0], P = .05) and pulse deficit (hazard ratio, 5.6 [1.3-24.0], P = .02) at presentation.

Conclusions

Patients presenting with type A aortic dissection and lower-extremity malperfusion have worse overall survival compared with those without lower-extremity malperfusion. However, not all patients with type A aortic dissection and lower-extremity malperfusion require revascularization.

Evaluation of Two Online Risk Prediction Models for the Mortality Rate of Acute Type A Aortic Dissection Surgery: The German Registry of Acute Aortic Dissection Type A Score and the European System for Cardiac Operative Risk Evaluation II

EuroSCORE II is one of the most widely utilized cardiovascular surgery risk scoring systems. Recently, a new online score calculator, namely the German Registry of Acute Aortic Dissection Type A (GERAADA), was launched to predict 30-day surgical mortality for acute type A aortic dissection (ATAAD) patients. The aim of this study is to evaluate the predictive performance of these two scores. We calculated the two scores for 1346 ATAAD patients from January 2012 to December 2021. The overall performance was evaluated using Brier scores and Hosmer-Lemeshow statistics. Receiver Operating Characteristic (ROC) curves were employed to assess diagnostic ability, and the standardized mortality ratio (SMR) was utilized to evaluate calibration. The GERAADA score and EuroSCORE II predicted 30-day mortality rates of 14.7% and 3.1%, respectively, while the observed rate was 12.5%. The predictive ability of EuroSCORE II (AUC 0.708, 95% CI: 0.664-0.792) was superior to that of the GERAADA score (0.648, 95% CI: 0.605-0.692). The GERAADA score had higher sensitivity but lower specificity than EuroSCORE II. And the GERAADA score may overestimate mortality (0.76, 95% CI: 0.65-0.89), while EuroSCORE II may underestimate the mortality rate (3.17, 95% CI: 2.92-3.44). The EuroSCORE II was superior in predicting surgical mortality among ATAAD patients. But the observed 30-day mortality rate certified a good calibration for the GERAADA score.

Validation of the German Registry for Acute Aortic Dissection Type A Score in predicting 30-day mortality after type A aortic dissection surgery

OBJECTIVES

No reliable scores are available to predict mortality following surgery for type A acute aortic dissection (TAAAD). Recently, the German Registry of Acute Aortic Dissection Type A (GERAADA) score has been developed. We aim to compare how the GERAADA score performs in predicting operative mortality for TAAAD to the European System for Cardiac Operative Risk Evaluation (EuroSCORE) II.

METHODS

We calculated the GERAADA score and EuroSCORE II in patients who underwent TAAAD repair at the Bristol Heart Institute. As there are no precise criteria to calculate the GERAADA score, we used 2 methods: a Clinical-GERAADA score, which evaluated malperfusion with clinical and radiological evidence, and a Radiological-GERAADA score, where malperfusion was assessed by computed tomography scan alone.

RESULTS

207 consecutive patients had surgery for TAAAD, and the observed 30-day mortality was 15%. The Clinical-GERAADA score showed the strongest discriminative power with an area under the curve (AUC) of 0.80 [95% confidence interval (CI) 0.71-0.89], while the Radiological-GERAADA score had an AUC of 0.77 (95% CI 0.67-0.87). EuroSCORE II showed acceptable discriminative power with an AUC of 0.77 (95% CI 0.67-0.87).

CONCLUSIONS

Clinical GERAADA score performed better than the other scores and it is specific and easy to use in the context of a TAAAD. Further validation of the new criteria for malperfusion is needed.

Risk factors for early death after surgery in patients with acute Stanford type A aortic dissection: A systematic review and meta-analysis

BACKGROUND

There are many risk factors related to early death after surgery among patients with acute Stanford type A aortic dissection (ATAAD) that have been analyzed in previous studies, but no evidence-based study has been conducted to confirm these risk factors.

AIMS

The aims of this study were to investigate risk factors for early death after surgery in patients with ATAAD via systematic review and meta-analysis and assess evidence-based strategies for preventing adverse events.

METHODS

The protocol for this study was prospectively registered with PROSPERO (CRD 42022332772). The authors systematically searched PubMed, Ovid, Scopus, Web of Science and Cochrane Library following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines from database construction to May 2021. Studies that met the selection criteria were determined by two independent researchers, and the odds ratios (ORs) and 95% confidence intervals (95% CIs) were reported for the risk factors and were pooled using Stata 15.0.

RESULTS

A total of 23 studies including 5510 patients met the inclusion criteria, and 10 risk factors were analyzed in this meta-analysis. The preoperative risk factors for early death after surgery in patients with ATAAD were age [(OR: 1.03, 95% CI (1.01, 1.06)], male sex [(OR: 1.43, 95% CI (1.06, 1.92)], shock [(OR: 1.91, 95% CI (1.06, 3.45)], malperfusion [(OR: 3.45, 95% CI (2.24, 5.31)] and cardiac tamponade [(OR: 3.89, 95% CI (1.17, 12.98)].

CONCLUSION

Patients with ATAAD who have an older age, male sex, shock, malperfusion and cardiac tamponade have a higher risk for early death after surgery. However, more highly homogenous studies are needed to demonstrate these results. Clinical staff should pay more attention to these factors and take individual actions to reduce mortality after surgery in patients with ATAAD.

ALDH2 knockout protects against aortic dissection

Background

The incidence and mortality of aortic dissection (AD) are increasing. In pathological studies, macrophages, T lymphocytes and dendritic cells were found in the tunica media of the aorta. Acetaldehyde dehydrogenase 2 (ALDH₂) gene polymorphisms are associated with a high incidence of hypertension in Asian populations. However, there is no clear evidence of the relationship between ALDH₂ and aortic dissection in Asians. The aim of this study was to investigate the incidence of aortic dissection in different ALDH₂ genotypes and explore changes in the vasculature.

Materials and methods

Three-week-old male mice were administered freshly prepared β-aminopropionitrile solution dissolved in drinking water (1 g/kg/d) for 28 days to induce TAD. An animal ultrasound imaging system was used to observe the formation of arterial dissection and changes in cardiac function. Subsequently, mice were euthanized by cervical dislocation. The aortas were fixed for HE staining and EVG staining to observe aortic elastic fiber tears and pseudoluma formation under a microscope.

Results

Knockout of ALDH₂ mitigated β-aminopropionitrile-induced TAD formation in animal studies. Ultrasound results showed that ALDH₂ knockout reduced the degree of ascending aortic widening and the incidence of aortic dissection rupture. Pathological sections of multiple aortic segments showed that the protective effect of ALDH₂ knockout was observed in not only the ascending aorta but also the aortic arch and descending aorta. The expression levels of genes related to NK CD56bright cells, Th17 cells, T cells and T helper cells were decreased in ALDH₂ knockout mice treated with β-aminopropionitrile for 28 days.

Conclusion

ALDH₂ knockout protects against aortic dissection by altering the inflammatory response and immune response and protecting elastic fibers.