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The Impact of Dedicated Aortic Teams and Centralisation of Aortic Services, and
Surgeon or Centre Specific Volumes on
Outcomes of Acute Type A Aortic Dissection
Amer Harky1*, Jeffrey Shi Kai Chan2, Ciaran Grafton-Clarke3 and Ahmed Al-Adhami4
1Department of Vascular Surgery, Countess of Chester Hospital, UK
2Faculty of Medicine, The Chinese University of Hong Kong, HK
3School of Medicine, University of Liverpool, UK
4Department of Cardiothoracic Surgery, Golden Jubilee National Hospital, UK
Submission:July 06, 2018; Published: August 24, 2018
*Corresponding author: Amer Harky, Department of Vascular Surgery, Countess of Chester Hospital Chester, CH2 1UL, United Kingdom,
How to cite this article: Amer H, Chan J S K, Ciaran G C, Ahmed Al-Adhami. The Impact of Dedicated Aortic Teams and Centralisation of Aortic Services,
and Surgeon or Centre Specific Volumes on Outcomes of Acute Type A Aortic Dissection. J Cardiol & Cardiovasc Ther. 2018; 12(1): 555828. DOI: 10.19080/JOCCT.2018.12.555828
Keywords: Aortic dissection; Surgeon volume; Aortic team
Acute Type A aortic dissection (ATAAD) is a surgical emergency with a high expected mortality and morbidity particularly if not managed operatively within the first 24 hours [1,2]. The gold standard treatment for aortic dissection remains open surgical repair  and although the mortality rates can be as high as 90%, 75% - 90% long term survival rates can be achieved if treatment is immediately constituted in the form of open surgical repair . Survival in patients with ATAAD is however variable with multifactorial predictors and determinants. Reports from the International Registry of Acute Aortic Dissection (IRAD) and the Society for Cardiothoracic Surgery in Great Britain and Ireland have reported operative mortality rates of 25.1% and 22.8% respectively [5,6]. In contrast, the German registry for Acute Aortic Dissection Type A (GERAADA) has reported lower mortality rates (17%)  and even lower motility figures of less than 10% being published by several single-centre studies [8-10]. In this short review we aim the impact of dedicated aortic teams, and surgeon or centre specific volumes on outcomes of acute type A aortic dissection.
In a multi-centre national observational database study examining the surgeon volume-outcome relationship, Bashir et al.  evaluated data from 1550 patients who underwent ATAAD repair by 249 individual consultant surgeons across United
Kingdom (UK) between 2007 and 2013. Although overall operative mortality was 18.3%, on multivariate analysis operating surgeons with a mean annual volume of 4 cases or less exhibited higher operative mortality rates than those with higher mean annual volumes (19.3% vs 12.6% respectively, p=0.015). Furthermore, in two separate large North-American studies undertaken by Chikwe et al.  and Kinpp et al. , outcomes of 5184 and 3013 patients with acute aortic dissections, respectively, were analysed. Both studies evaluated the effects of centre volumes on operative mortality but Chikwe and colleagues however have also assessed the impact of individual surgeon volume on outcomes and overall performance. Chikwe et al.  reported that surgeons with an average of less than 1 aortic dissection repair annually had a mean operative mortality of 27.5%, compared with 17.0% for those performing 5 or more such procedures annually (odds ratio 1.78; 95% confidence interval 1.39 to 2.29; p < 0.001). A similar inverse relationship was seen between institution volume and operative mortality with higher mortality rates (27.4% versus 16.4%; p < 0.001) in low volume institutions (3 or fewer acute aortic dissection repairs per year) than high volume centres (13 or more aortic dissection annually). Despite disagreements in what defines low, medium or high-volume surgery, there was consensus in both studies on the effect of centre volume on mortality with high volume centres reporting lower mortality rates than their lower volume counterparts. Annual operative volume was inversely proportional with mortality.
Similarly, in a systematic review of 79,131 patients by
Mariscalclo and colleagues , high-volume centres or individual
surgeons had lower mortality rates (OR 0.51; 95% CI 0.46-0.56,
and OR 0.41, 95% CI 0.25-0.66, respectively). All these findings
were also corroborated by several studies supporting the idea
that ATAAD should be managed by high volume centres and highvolume
operating surgeons [14-16].
Although It is clear from published literature that patients
with ATAAD have better outcomes if treated in high volume
centres by high-volume surgeons [3,10-16]. However, the
impact of establishing dedicated teams for aortic surgery on the
perioperative outcomes is less well studied .
In a large study by Andersen et al. , outcomes of 128 patients
undergoing surgery before (56 patients) and after (72 patients)
the introduction of a multidisciplinary Thoracic Aortic Surgery
Program (TASP) with a dedicated aortic team were analysed.
Reported operative mortality rates significantly improved from
33.9% to 2.8%. These results were further supported by a recent
systematic review of observational studies  concluding that
centres with specific multidisciplinary aortic programmes and
dedicated on-call aortic teams showed a significant reduction in
mortality following surgery for acute aortic syndrome (OR 0.31;
95% CI 0.19–0.5, and OR 0.37; 95% CI 0.15-0.87, respectively).
Several other studies have taken further steps and have
reported on the impact of a dedicated on- call aortic team and
multidisciplinary meeting that resulted in improved perioperative
outcomes, especially lower mortality rates [19-21]. Among
those studies, Lenos et al.  reported a lower mortality rate
in centres with a TASP (4% vs 21.8%, p< 0.001), and similarly
Beller and associates  report improved mortality (9.7% vs
30.8%, P=0.014) in their single centre following introduction
of multidisciplinary aortic surgery team and standardised
management protocols for ATAAD patients. Moreover, in a study
evaluating outcomes of general thoracic aortic surgery, Sales et
al.  reported a total reduction in all-cause operative mortality
(9.7% vs 22.9%, p=0.008) after introduction of the Centre of
Aortic Surgery highlighting its importance of dedicated aortic
teams in achieving better outcomes.
With regionalisation and centralisation of subspecialist
services such as aortic surgery, it is evident that this there are
several advantages, including the positive volume-outcome
effect and concentration of resources. In contrast however, it is
also important to note that centralisation is almost invariably
associated with reduced access to subspecialist services and any
such steps must be accompanied with an analysis of the regional
geography, population and needs.
Published literature surrounding the impact of centralisation
of aortic services (with dedicated on-call and aortic
multidisciplinary teams) including the management patients with
type A aortic dissection is growing with increasing supportive
evidence to suggest improved mortality and morbidity. Surgeon
and institutional case volume were independently associated with
improved outcomes after aortic dissection repair.