Hybrid versus conventional open repair for aortic arch dissection

Background

A dissection of the aorta is a separation or tear of the intima from the media. This tear allows blood to flow not only through the original aortic flow channel (known as the true lumen), but also through a second channel between the intima and media (known as the false lumen). A dissection can then develop along the artery, secondary to the blood flowing into the space. Aortic dissection is a life-threatening condition which can rapidly be fatal. Aortic dissection that affects the ascending aorta, aortic arch and the descending aorta is a challenge for physicians. There is debate on the best surgical approach for aortic arch dissection. People with ascending aortic dissection have poor rates of survival. Currently, open surgical repair is regarded as the standard treatment for aortic arch dissection.

Study characteristics and key results

We searched medical databases for clinical trials that compared the use of a hybrid technique versus open surgical technique for people who suffered from arterial dissection of the aortic arch (last search February 2021). We identified one ongoing study and two unpublished studies, which met the inclusion criteria for the review. However, due to a lack of published study data, we could not compare the outcomes of hybrid repair to conventional open repair for aortic arch dissection.

Certainty of the evidence

In the absence of study data for those identified as eligible for inclusion in the review, it was not possible to assess the certainty of the evidence.

Conclusion

There is an absence of data for patients with this type of condition. Reasons may include its acute nature, and the need to intervene quickly in a surgical environment; patients with aortic arch dissection often suffer from many other conditions, which prevent them having particular surgeries; and often centres and surgical expertise may be lacking in this area, leading to a culture of using conventional rather than contemporary methods.

Future studies need to have adequate sample sizes and follow-up, and assess clinically relevant outcomes, in order to determine the best treatment for people with aortic arch dissection. It must be noted that this may not be feasible due to the reasons mentioned.

Authors' conclusions: 

This review revealed one ongoing RCT and two unpublished RCTs evaluating hybrid versus conventional open repair for aortic arch surgery. Observational data suggest that hybrid repair for aortic arch dissection could potentially be favourable, but conclusions can not be drawn from these studies, which are highly selective, and are based on the clinical status of the patient, the presence of comorbidities and the skills of the operators. However, a conclusion about its definitive benefit over conventional open surgical repair cannot be made from this review without published RCTs or CCTs.

Future RCTs or CCTs need to have adequate sample sizes and follow-up, and assess clinically-relevant outcomes, in order to determine the optimal treatment for people with aortic arch dissection. It must be noted that this may not be feasible, due to the reasons mentioned.

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Background: 

A dissection of the aorta is a separation or tear of the intima from the media. This tear allows blood to flow not only through the original aortic flow channel (known as the true lumen), but also through a second channel between the intima and media (known as the false lumen). Aortic dissection is a life-threatening condition which can be rapidly fatal. There is debate on the optimal surgical approach for aortic arch dissection. People with ascending aortic dissection have poor rates of survival. Currently open surgical repair is regarded as the standard treatment for aortic arch dissection. We intend to review the role of hybrid and open repair in aortic arch dissection.

Objectives: 

To assess the effectiveness and safety of a hybrid technique of treatment over conventional open repair in the management of aortic arch dissection.

Search strategy: 

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and AMED databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 8 February 2021. We also undertook reference checking for additional studies.

Selection criteria: 

We included randomised controlled trials (RCTs) and clinical controlled trials (CCTs), which compared the effects of hybrid repair techniques versus open surgical repair of aortic arch dissection. Outcomes of interest were dissection-related mortality and all-cause mortality, neurological deficit, cardiac injury, respiratory compromise, renal ischaemia, false lumen thrombosis (defined by partial or complete thrombosis) and mesenteric ischaemia.

Data collection and analysis: 

Two review authors independently screened all records identified by the literature searches to identify those that met our inclusion criteria. We planned to undertake data collection and analysis in accordance with recommendations described in the Cochrane Handbook for Systematic Reviews of Interventions. We planned to assess the certainty of the evidence using GRADE.

Main results: 

We identified one ongoing study and two unpublished studies that met the inclusion criteria for the review. Due to a lack of study data, we could not compare the outcomes of hybrid repair to conventional open repair for aortic arch dissection.