Management of patients with acute aortic syndrome through a regional rapid transport system

The Role of Integrated Air Transport System in Managing Patients with Abdominal Aortic Aneurysm Rupture

OBJECTIVE

Ruptured abdominal aortic aneurysms (rAAAs) are highly morbid emergencies. Not all hospitals are equipped to repair them, and an air ambulance network may aid in regionalising specialty care to quaternary referral centres. The association between travel distance by air ambulance and rAAA mortality in patients transferred as an emergency for repair was examined.

METHODS

A retrospective review of institutional data. Adults with rAAA (2002 - 2019) transferred from an outside hospital (OSH) to a single quaternary referral centre for repair via air ambulance were identified. Patients who arrived via ground transport or post-repair at an OSH for continued critical care were excluded. Patients were divided into near and far groups based on the 75th percentile of the straight line travel distance (> 72 miles) between hospitals. The primary outcome was 30 day mortality. Multivariable logistic regression was used to assess the association between distance and mortality after adjusting for age, sex, ethnicity, cardiovascular comorbidities, and repair type.

RESULTS

A total of 290 patients with rAAA were transported a median distance of 40.4 miles (interquartile range 25.5, 72.7) with 215 (74.1%) near and 75 (25.9%) far patients. Both the near and far groups had similar ages, sex, and ethnicity. There was no difference in pre-operative loss of consciousness, intubation, or cardiac arrest between groups. Endovascular aneurysm repair utilisation and intra-operative aortic occlusion balloon use were also similar. Neither the observed (26.8% vs. 23.9%, p = .61) nor the adjusted odds ratio (0.70, 95% confidence interval 0.36 - 1.39, p = .32) 30 day mortality rate differed significantly between the near and far groups.

CONCLUSION

Increasing distance travelled during transfer by air ambulance was not associated with worse outcomes in patients with rAAA. The findings support the regionalisation of rAAA repair to large quaternary centres via an integrated and robust air ambulance network.

Role of Helicopter Transfer and Cloud-Type Imaging for Acute Type A Aortic Dissection

BACKGROUND

 This study explored if long-distance transfer was safe for patients suffering from acute aortic dissection type A (AADA) and also analyzed the effectiveness of helicopter transfer and cloud-type imaging transfer systems for such patients in northern Hokkaido, Japan.

METHODS AND RESULTS

 The study included 112 consecutive patients who underwent emergency surgical treatment for AADA from April 2014 to September 2020. The patients were divided into two groups according to the location of referral source hospitals: the Asahikawa city group (group A, n = 49) and the out-of-the-city group (group O, n = 63). Use of helicopter transfer (n = 13) and cloud-type telemedicine (n = 20) in group O were reviewed as subanalyses.Transfer distance differed between groups (4.2 ± 3.5 km in group A vs 107.3 ± 69.2 km in group O; p = 0.0001), but 30-day mortality (10.2% in group A vs 7.9% in group O; p = 0.676) and hospital mortality (12.2% in group A vs 9.5% in group O; p = 0.687) did not differ. Operative outcomes did not differ with or without helicopter and cloud-type telemedicine, but diagnosis-to-operation time was shorter with helicopter (240.0 ± 70.8 vs 320.0 ± 78.5 minutes; p = 0.031) and telemedicine (242.0 ± 75.2 vs 319.0 ± 83.8 minutes; p = 0.007).

CONCLUSION

 We found that long-distance transfer did not impair surgical outcomes in AADA patients, and both helicopter transfer and cloud-type telemedicine system could contribute to the reduction of diagnosis-to-operation time in the large Hokkaido area. Further studies are mandatory to investigate if both the systems will improve clinical outcomes.

Influence of a regional network combined with a systematic multidisciplinary approach on the outcomes of patients with acute type A aortic dissection

BACKGROUND

Whether in patients with acute type A aortic dissection reduction of intervals between onset of symptoms and diagnosis influences patient outcomes is still not completely defined.

METHODS

In 199 patients with acute type A aortic dissection, the efficacy of a systematic multidisciplinary approach and institution of a regional network were evaluated; 90 patients operated before 2016 (Group1) were compared with 109 repaired after 2016 (Group2) for early and late outcomes.

RESULTS

Mortality was reduced from 13% in Group1 to 4% in Group2 (p = 0.013). In Group2 a more patients (46%) had arch replacement compared to Group1 (29%)(p = 0.06). In Group2 axillary artery cannulation was almost routinely used (91% vs 67%, p < 0.001) with shorter circulatory arrest time (37 vs 44 min, p < 0.001). The interval from diagnosis to surgery dropped from 210 min in Group1 to 160 min in Group2 (p < 0.001); this reduction was evident both in patients admitted to the emergency department of a spoke and/or a hub center. Patients presenting with or developing shock were reduced from Group1 to Group2 and in particular those reaching the hub center from spoke centers. Survival at 1 and 5 years was 82 ± 4% and 70 ± 5% in Group1 vs 92 ± 3% and 87 ± 8% in Group2 (p = 0.007).

CONCLUSIONS

Outcomes of patients with acute type A aortic dissection improved using a systematic multidisciplinary approach while a network between spoke and hub centers reduced intervals between diagnosis, transportation to hub center and repair, limiting the incidence of tamponade and shock.

Benchmarking a Center of Excellence in Vascular Surgery: Using Acute Physiology and Chronic Health Evaluation II to Validate Outcomes in a Tertiary Care Institute

OBJECTIVE

The Society of Vascular Surgery (SVS) has made it a top priority to implement verification of vascular "centers of excellence". Our institutional aortic network was established in 2008 in order to standardize care of patients with suspected acute aortic pathology. The implementation and success of this program has been previously reported. We sought to use our experience as a benchmark for which to develop prognostic modeling to quantify clinical status upon admission and help predict outcomes. Our objective was to validate the Acute Physiology and Chronic Health Evaluation (APACHE) II scoring system using a cohort of aortic emergencies transferred by an organized transfer network.

METHOD

This was a retrospective, single institution review of patients transferred through an institutional aortic network for acute aortic pathology from 2017-2018. Demographics, comorbidities, aortic diagnosis, APACHE II score, as well as 30-day mortality were recorded. Associations with 30-day mortality were evaluated using two-sample t-tests, ANOVA models, Pearson chi-square tests and Fisher exact tests. Receiver operating characteristic (ROC) curves were fit overall and by pathology to predict 30-day mortality by Apache II total score.

RESULTS

There were 395 consecutive transfers were identified. The mean age was 64.7 years. Diagnoses included Type A Dissection (n = 134), Type B (n = 81), Aortic Aneurysm (n = 122), and PAU/IMH (n = 27). Mean APACHE II score on arrival was 12. Overall there were 53 deaths (13.4%) in the cohort. Patients that died had significantly higher Apache II total scores (11.3 vs 16.5, P < .001). The area under the receiver operator characteristic (ROC) curve (AUC) was .66 for the full cohort, indicating a poor clinical prediction test.

CONCLUSION

APACHE II score is a poor predictor of 30-day mortality in a large transfer network accepting all aortic emergencies. The authors believe further refining a prognostic model for diverse population will not only help in predicting outcomes but to objectively quantify illness severity in order to have a basis for comparison among institutions and verification of "centers of excellence".

Simple Death Risk Models to Predict In-hospital Outcomes in Acute Aortic Dissection in Emergency Department

Objective

We sought to find a bedside prognosis prediction model based on clinical and image parameters to determine the in-hospital outcomes of acute aortic dissection (AAD) in the emergency department.

Methods

Patients who presented with AAD from January 2010 to December 2019 were retrospectively recruited in our derivation cohort. Then we prospectively collected patients with AAD from January 2020 to December 2021 as the validation cohort. We collected the demographics, medical history, treatment options, and in-hospital outcomes. All enrolled patients underwent computed tomography angiography. The image data were systematically reviewed for anatomic criteria in a retrospective fashion by three professional radiologists. A series of radiological parameters, including the extent of dissection, the site of the intimal tear, entry tear diameter, aortic diameter at each level, maximum false lumen diameter, and presence of pericardial effusion were collected.

Results

Of the 449 patients in the derivation cohort, 345 (76.8%) were male, the mean age was 61 years, and 298 (66.4%) had a history of hypertension. Surgical repair was performed in 327 (72.8%) cases in the derivation cohort, and the overall crude in-hospital mortality of AAD was 10.9%. Multivariate logistic regression analysis showed that predictors of in-hospital mortality in AAD included age, Marfan syndrome, type A aortic dissection, surgical repair, and maximum false lumen diameter. A final prognostic model incorporating these five predictors showed good calibration and discrimination in the derivation and validation cohorts. As for type A aortic dissection, 3-level type A aortic dissection clinical prognosis score (3ADPS) including 5 clinical and image variables scored from −2 to 5 was established: (1) moderate risk of death if 3ADPS is <0; (2) high risk of death if 3ADPS is 1–2; (3) very high risk of death if 3ADPS is more than 3. The area under the receiver operator characteristic curves in the validation cohorts was 0.833 (95% CI, 0.700–0.967).

Conclusion

Age, Marfan syndrome, type A aortic dissection, surgical repair, and maximum false lumen diameter can significantly affect the in-hospital outcomes of AAD. And 3ADPS contributes to the prediction of in-hospital prognosis of type A aortic dissection rapidly and effectively. As multivariable risk prediction tools, the risk models were readily available for emergency doctors to predict in-hospital mortality of patients with AAD in extreme clinical risk.

Misdiagnosis of Thoracic Aortic Disease Occurs Commonly in Emergency Transfers

BACKGROUND

Acute aortic syndromes (AAS) are prone to misdiagnosis by facilities with limited diagnostic experience. We assessed long-term trends in misdiagnosis among patients transferred to a tertiary care facility with presumed AAS.

METHODS

Our institutional transfer center database was queried for emergency transfers in patients with a diagnosis of acute aortic syndromes or thoracic aortic aneurysm between January 2008 and May 2018. 784 patients were classified as emergency transfer for presumed AAS. Transferring diagnosis and actual diagnosis were compared through a review of physician notes and radiology reports from referring facilities and our center.

RESULTS

Mean age was 62 years, with 61% (n=478) men. Differences in transferring diagnosis and actual diagnosis were identified in 89 (11.4%) patients. Among misdiagnosed patients, the wrong classification of Stanford Type A or Type B dissections was identified among 24 (27%) patients. Twenty-three (26%) patients with a referring diagnosis of aortic dissection were found to have no dissection. Eighteen patients (20%) transferred for contained/impending rupture did not have signs of rupture. All misdiagnoses were secondary to misinterpretation of radiographic imaging, with motion artifacts (n=14, 16%) and post-surgical changes (n=22, 25%) being common sources of diagnostic error. Sixty-four (72%) patients underwent repeat scans at our facility due to limited access or sub-optimal quality of outside imaging.

CONCLUSIONS

While AAS misdiagnosis rates appear to be improving from the prior decade, there are opportunities for improved physician awareness through campaigns such as "Think Aorta." Centralized web-based imaging may prevent the costly hazards of unnecessary emergency transfer.

Time is of the essence: where can we improve care in acute aortic dissection?

OBJECTIVES

In acute aortic dissection type A various components of the diagnostic and logistic pathways may affect the time to definitive treatment. This study aimed to characterize these components and to identify factors delaying the optimal management within our institutional referral network.

METHODS

Between January 2017 and January 2020, 96 consecutive patients with classical aortic dissection type A were admitted (28%) or referred (72%) to our tertiary care centre and analysed retrospectively. Data are presented as medians (25th-75th quartile).

RESULTS

Median age was 66 years (56-74), 63% were male. Most of the patients were primarily admitted to a cardiology department (40%), whereas about a fourth were admitted to departments for internal medicine (26%) and general surgery (27%). The median interval from the onset of symptoms to hospital admission was 2.1 (1-4.4) h. From admission to confirmed diagnosis it took 2.1 (0.6-9.5) h and the median interval from confirmed diagnosis to admission at our specialized tertiary care aortic centre was 1.5 (0.9-2.4) h. Following admission to our centre, 1.1 (0.5-1.9) h passed until the induction of anaesthesia and 0.8 (0.0-1.1) h until the start of surgery. The total interval from the onset of symptoms to the start of surgery was 7.6 h (5.1-12.3).

CONCLUSIONS

The marked variability of the time from symptoms to diagnosis at any medical facility demonstrates the importance of awareness in the optimization of the treatment of acute aortic dissection type A.

Management strategy for lower extremity malperfusion due to acute aortic dissection

OBJECTIVE

Aortic dissection can result in devastating cerebral, visceral, renal, spinal, and extremity ischemia. We describe the management and outcomes of patients presenting with aortic dissection and lower extremity malperfusion (LEM).

METHODS

A single-center institutional aortic database was queried for patients with aortic dissection and LEM from 2011 to 2019. The primary end point was resolution of LEM after aortic repair. Secondary end points were amputation, in-hospital mortality, time to intervention, and postoperative complications.

RESULTS

Of 769 patients with aortic dissection, 42 (5.5%) presented acutely with LEM: 16 with Stanford type A and 26 Stanford type B aortic dissection (age 55 ± 13 years; 90% men). Most presented as Rutherford IIB symptoms, but patients with type A had Rutherford III more often, compared with those with type B. Aortic repair was performed before limb interventions in 36 patients (86%; 19 TEVAR, 16 open arch and ascending repair, and 1 open descending aortic repair with fenestration). Seven (19%) had immediate failure with persistent malperfusion recognized in the operating room and underwent additional limb intervention, including extra-anatomic revascularization (n = 4), iliac stenting (n = 2), and femoral patch with septal fenestration or tacking (n = 2). Three patients (8%) had early delayed failure requiring extra-anatomic bypass in two and amputation in one. In contrast, six patients had limb-first intervention with extra-anatomic revascularization. None had immediate failure, but one-half had early delayed failure requiring proximal aortic intervention: two TEVAR and one open aortic fenestration. Limb-first patients were more likely to have early delayed failure compared with aortic dissection treated first patients (50% vs 8%; P = .029). The amputation rate was 2%, occurring in one type A patient. The overall in-hospital mortality was 7% (n = 3), with no difference between type A and type B aortic dissection. There was no difference in surgical site infection, postoperative dialysis need, stroke, and myocardial infarction.

CONCLUSIONS

In patients presenting with acute aortic dissection with limb ischemia, resolution of the malperfusion occurs in the majority of cases after primary aortic dissection intervention, emphasizing the usefulness of urgent TEVAR for complicated type B and open repair of type A before lower extremity intervention. Limb-first interventions have a higher early delayed failure rate and thus require more frequent reoperation. However, the overall amputation rate in LEM owing to aortic dissection remains low.

Incidence and Mortality Rates of Thoracic Aortic Dissection in Korea - Inferred from the Nationwide Health Insurance Claims

BACKGROUND

Aortic dissection (AD) is one of the most catastrophic diseases and is associated with high morbidity and mortality. The aim of this study is to investigate the hospital incidence and mortality rates of thoracic AD in Korea using a nationwide database.

METHODS

We conducted a nationwide population-based study using the health claims data of the National Health Insurance Service in Korea. From 2005 to 2016, adult patients newly diagnosed with AD were included. All patients were divided into the following four subgroups by treatment: type A surgical repair (TASR), type B surgical repair (TBSR), thoracic endovascular aortic repair (TEVAR), and medical management (MM). The incidence rate, mortality rate, and risk factors of in-hospital mortality were evaluated.

RESULTS

In total, 18,565 patients were newly diagnosed with AD (TASR, n = 4,319 [23.3%]; TBSR, n = 186 [1.0%]; TEVAR, n = 697 [3.8%]; MM, n = 13,363 [72.0%]). The overall AD incidence rate was 3.76 per 100,000 person-years and exhibited a gradual increase during the study period (3.29 to 4.82, P < 0.001). The overall in-hospital mortality rate was 10.84% and remained consistent (P = 0.57). However, the in-hospital mortality rate decreased in the TASR subgroup (18.23 to 11.27%, P = 0.046). An older age, the female sex, hypertension, and chronic kidney disease were independent risk factors for in-hospital mortality.

CONCLUSION

The incidence of thoracic AD has gradually increased in Korea. The in-hospital mortality in the TASR subgroup decreased over the decade, although the overall mortality of AD patients did not change.

Factors Affecting Outcomes in Acute Type A Aortic Dissection: A Systematic Review

Acute type A aortic dissection is a clinical emergency and is associated with significant morbidity and mortality rates if not managed promptly in specialised and high-volume centres. The mortality rate is increased by 1% for each hour delay in management; however, with advancement in clinical practice, diagnostic imaging and clinician awareness, this has been dramatically reduced to below 30% in most international centres. Not only timing of recognition of the pathology, but also other factors can significantly affect outcomes of such critical pathology. This includes, but is not limited to, age, extent of the pathology, existence of connective tissue disorders, hypertension, diabetes mellitus and surgeon experience. This narrative review will focus on current clinical practice and the evidence behind optimising each factor to minimise adverse outcomes in such high-risk cohort.

Management of Acute Aortic Dissection During Critical Care Air Medical Transport

Acute aortic dissection is a time-critical emergency that air medical teams must be capable of transporting. Aortic dissections can manifest a myriad of complications in which prompt recognition and tailored treatments may mitigate additional physiological burden and limit dissection flap propagation. The purpose of this review is to discuss specific critical scenarios that air medical providers may be faced with and to equip them with a pathophysiological understanding of the disease and best practices for the management of acute aortic dissections.

[Type A acute aortic syndromes: Assessment of the management delays in an emergency medicine network]

OBJECTIVE

To assess the diagnostic delay (between first hospital medical contact and diagnosis) and the surgical delay (between diagnosis and incision) of type A acute aortic syndromes (AAAS) within the RENAU (REseau Nord Alpin des Urgences), organizing the management of emergency medicine care in the French North Alpine Arc.

PROCEDURE

Multicenter retrospective study between 2012 and 2016 on the AAAS operated in the RENAU heart surgical centers (Annecy, Grenoble). Post-traumatic, iatrogenic or chronic lesions, incidental discoveries and deaths before surgery were excluded.

RESULTS

One hundred and ninety-seven patients were included with a median age [IQR] of 65 years [58; 73] of which 67% were men. The median diagnosis delay was 88min [46;241] and the median surgical delay was 193min [146;249]. Initial management was performed by the SMUR for 102 patients (52%), 7% of whom received a pre-hospital transthoracic ultrasound. 52 patients (26%) presented themselves spontaneously to the emergency department. Patients were initially admitted in a center without cardiac surgery in 65% of cases. The CT scan was the diagnostic test in 81% of cases. The postoperative hospital mortality was 16%.

CONCLUSION

Referring to IRAD data reporting a median diagnostic and surgical delay of 258min each, our study suggests that the RENAU organization may be associated with reduced diagnostic and surgical delays for patients with SAAA.

Postoperative Development of Abdominal Compartment Syndrome among Patients Undergoing Endovascular Aortic Repair for Ruptured Abdominal Aortic Aneurysms

BACKGROUND

Abdominal compartment syndrome (ACS) has a reported incidence of 9%-14% among trauma patients. However, in patients with similar hemodynamic changes, the incidence of ACS remains unclear. Our aim was to determine the incidence of ACS among patients undergoing endovascular aortic repair (EVAR) for ruptured abdominal aortic aneurysms (rAAAs) and to identify associated risk factors.

METHODS

A retrospective review was performed for consecutive patients who underwent EVAR for rAAA from March 2010 to November 2016 at our institution. The development of ACS was diagnosed based on a variety of factors, including bladder pressure, laboratory abnormalities, hemodynamic monitoring, and clinical evaluation. Previously validated risk factors for ACS development in trauma and EVAR patients (preoperative hypotension, aggressive fluid resuscitation, postoperative anemia, use of an aorto-uniiliac graft, and placement of an aortic occlusive balloon) were analyzed. Association between patient characteristics and ACS development was analyzed using the Fisher's exact test.

RESULTS

During the study period, 25 patients had image-confirmed rAAA and underwent emergent EVAR. Mortality rate was 28% (n = 7), and ACS incidence was 12% (n = 3). Of the analyzed risk factors, hypotension on arrival (P = 0.037), transfusion of 3 or more units of packed red blood cells (P = 0.037), and postoperative anemia (P = 0.02) were all significantly associated with postoperative ACS development. In addition, having greater than 3 of the studied risk factors was associated with increased odds of developing ACS (P = 0.015), and having greater than 4 of the studied risk factors showed the strongest association with ACS development (P = 0.0017).

CONCLUSIONS

Overresuscitation should be avoided in patients with rAAA. In addition, patients who present with multiple risk factors for ACS should be monitored very closely with serial bladder pressures and may require decompression laparotomy immediately after EVAR.