Endovascular versus conventional medical treatment for uncomplicated chronic type B aortic dissection

Interventions in Acute or Subacute Phase for Type B Aortic Dissection

The treatment strategy for acute and subacute Stanford type B aortic dissection has changed significantly since the advent of thoracic endovascular aortic repair (TEVAR). Indication for invasive treatment: In addition to the conventional complicated cases (rupture or malperfusion case), the indication for invasive treatment now includes cases with refractory hypertension, persistent or recurrent pain, large aortic diameter, and other conditions that are considered to have a poor prognosis with conservative treatment. Treatment methods: TEVAR is the first choice for acute, subacute, and early chronic-stage treatment, and when this is not possible, other techniques (fenestration and graft replacement) are chosen. Treatment timing: The timing of invasive treatment should be emergent in life-threatening conditions (for rupture or malperfusion case) and immediate in symptomatic cases, while in other cases, preemptive TEVAR is considered appropriate on a scheduled timing within 6 months of onset. (This is a translation of Jpn J Vasc Surg 2023; 32: 157-163.).

Drugs to reduce bleeding and transfusion in major open vascular or endovascular surgery: a systematic review and network meta-analysis

BACKGROUND

Vascular surgery may be followed by internal bleeding due to inadequate surgical haemostasis, abnormal clotting, or surgical complications. Bleeding ranges from minor, with no transfusion requirement, to massive, requiring multiple blood product transfusions. There are a number of drugs, given systemically or applied locally, which may reduce the need for blood transfusion.

OBJECTIVES

To assess the effectiveness and safety of anti-fibrinolytic and haemostatic drugs and agents in reducing bleeding and the need for blood transfusion in people undergoing major vascular surgery or vascular procedures with a risk of moderate or severe (> 500 mL) blood loss.

SEARCH METHODS

We searched: Cochrane Central Register of Controlled Trials; MEDLINE; Embase; CINAHL, and Transfusion Evidence Library. We also searched the WHO ICTRP and ClinicalTrials.gov trial registries for ongoing and unpublished trials. Searches used a combination of MeSH and free text terms from database inception to 31 March 2022, without restriction on language or publication status.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in adults of drug treatments to reduce bleeding due to major vascular surgery or vascular procedures with a risk of moderate or severe blood loss, which used placebo, usual care or another drug regimen as control.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were units of red cells transfused and all-cause mortality. Our secondary outcomes included risk of receiving an allogeneic blood product, risk of reoperation or repeat procedure due to bleeding, risk of a thromboembolic event, risk of a serious adverse event and length of hospital stay. We used GRADE to assess certainty of evidence.

MAIN RESULTS

We included 22 RCTs with 3393 participants analysed, of which one RCT with 69 participants was reported only in abstract form, with no usable data. Seven RCTs evaluated systemic drug treatments (three aprotinin, two desmopressin, two tranexamic acid) and 15 RCTs evaluated topical drug treatments (drug-containing bioabsorbable dressings or glues), including fibrin, thrombin, collagen, gelatin, synthetic sealants and one investigational new agent. Most trials were conducted in high-income countries and the majority of the trials only included participants undergoing elective surgery. We also identified two ongoing RCTs. We were unable to perform the planned network meta-analysis due to the sparse reporting of outcomes relevant to this review. Systemic drug treatments We identified seven trials of three systemic drugs: aprotinin, desmopressin and tranexamic acid, all with placebo controls. The trials of aprotinin and desmopressin were small with very low-certainty evidence for all of our outcomes. Tranexamic acid versus placebo was the systemic drug comparison with the largest number of participants (2 trials; 1460 participants), both at low risk of bias. The largest of these included a total of 9535 individuals undergoing a number of different higher risk surgeries and reported limited information on the vascular subgroup (1399 participants). Neither trial reported the number of units of red cells transfused per participant up to 30 days. Three outcomes were associated with very low-certainty evidence due to the very wide confidence intervals (CIs) resulting from small study sizes and low number of events. These were: all-cause mortality up to 30 days; number of participants requiring an allogeneic blood transfusion up to 30 days; and risk of requiring a repeat procedure or operation due to bleeding. Tranexamic acid may have no effect on the risk of thromboembolic events up to 30 days (risk ratio (RR) 1.10, 95% CI 0.88 to 1.36; 1 trial, 1360 participants; low-certainty evidence due to imprecision). There is one large ongoing trial (8320 participants) comparing tranexamic acid versus placebo in people undergoing non-cardiac surgery who are at high risk of requiring a red cell transfusion. This aims to complete recruitment in April 2023. This trial has primary outcomes of proportion of participants transfused with red blood cells and incidence of venous thromboembolism (DVT or PE). Topical drug treatments Most trials of topical drug treatments were at high risk of bias due to their open-label design (compared with usual care, or liquids were compared with sponges). All of the trials were small, most were very small, and few reported clinically relevant outcomes in the postoperative period. Fibrin sealant versus usual care was the topical drug comparison with the largest number of participants (5 trials, 784 participants). The five trials that compared fibrin sealant with usual care were all at high risk of bias, due to the open-label trial design with no measures put in place to minimise reporting bias. All of the trials were funded by pharmaceutical companies. None of the five trials reported the number of red cells transfused per participant up to 30 days or the number of participants requiring an allogeneic blood transfusion up to 30 days. The other three outcomes were associated with very low-certainty evidence with wide confidence intervals due to small sample sizes and the low number of events, these were: all-cause mortality up to 30 days; risk of requiring a repeat procedure due to bleeding; and risk of thromboembolic disease up to 30 days. We identified one large trial (500 participants) comparing fibrin sealant versus usual care in participants undergoing abdominal aortic aneurysm repair, which has not yet started recruitment. This trial lists death due to arterial disease and reintervention rates as primary outcomes.

AUTHORS' CONCLUSIONS

Because of a lack of data, we are uncertain whether any systemic or topical treatments used to reduce bleeding due to major vascular surgery have an effect on: all-cause mortality up to 30 days; risk of requiring a repeat procedure or operation due to bleeding; number of red cells transfused per participant up to 30 days or the number of participants requiring an allogeneic blood transfusion up to 30 days. There may be no effect of tranexamic acid on the risk of thromboembolic events up to 30 days, this is important as there has been concern that this risk may be increased. Trials with sample size targets of thousands of participants and clinically relevant outcomes are needed, and we look forward to seeing the results of the ongoing trials in the future.

Outcomes and risk management in type B aortic dissection patients with acute kidney injury: a concise review

Purpose

Type B aortic dissection is a rare but life-threatening disease. Thoracic endovascular aortic repair (TEVAR) was widely used for Type B aortic dissection patients in the last decade due to the lower mortality and morbidity compared with open chest surgical repair (OCSR). AKI in type B aortic dissection is a well-recognized complication and indicates poor short-term and long-term outcome. The objective of this concise review was to identify the risk factors and the impact of AKI on type B aortic dissection patients.

Methods and results

A literature search was performed using PubMed, Embase, MEDLINE, and Cochrane Library with the search terms ‘type B aortic dissection’ and ‘acute kidney injury’ (AKI), and all English-language literatures published in print or available online from inception through August 2020 were thoroughly reviewed. Studies that reported relative AKI risks and outcomes in type B aortic dissection patient were included. Major mechanisms of AKI in type B aortic dissection included renal hypoperfusion, inflammation response, and the use of contrast medium. Type B aortic dissection patients with AKI significantly had increased hospital stay duration, need of renal replacement therapy, and 30-d and 1-year mortality.

Conclusions

AKI in type B aortic dissection is a well-recognized complication and associated with poor short-term and long-term outcome. Early identification of high-risk patients, early diagnosis of AKI, stabilization of the hemodynamic parameters, avoidance of nephrotoxic drugs, and optimization of the use of contrast agents are the major strategies for the reduction of AKI in type B aortic dissection patients.

Use of 3D Printing in Preoperative Planning and Training for Aortic Endovascular Repair and Aortic Valve Disease

Introduction

Three-dimensional (3D) printing has become an affordable tool for assisting heart surgeons in the aorta endovascular field, both in surgical planning, education and training of residents and students. This technique permits the construction of physical prototypes from conventional medical images by converting the anatomical information into computer aided design (CAD) files.

Objective

To present the 3D printing feature on developing prototypes leading to improved aortic endovascular surgical planning, as well as transcatheter aortic valve implantation, and mainly enabling training of the surgical procedure to be performed on patient's specific condition.

Methods

Six 3D printed real scale prototypes were built representing different aortic diseases, taken from real patients, to simulate the correction of the disease with endoprosthesis deployment.

Results

In the hybrid room, the 3D prototypes were examined under fluoroscopy, making it possible to obtain images that clearly delimited the walls of the aorta and its details. The endovascular simulation was then able to be performed, by correctly positioning the endoprosthesis, followed by its deployment.

Conclusion

The 3D printing allowed the construction of aortic diseases realistic prototypes, offering a 3D view from the two-dimensional image of computed tomography (CT) angiography, allowing better surgical planning and surgeon training in the specific case beforehand.

Assessing Aortic Remodeling after Thoracic Endovascular Aortic Repair (TEVAR) in DeBakey IIIb Aortic Dissection: A Retrospective Study

PURPOSE

This study analyzed the different levels of aortic remodeling in patients with DeBakey IIIb aortic dissection (AD) after thoracic endovascular aortic repair (TEVAR) at a single center.

METHODS

In all, 66 patients with DeBakey IIIb AD who underwent TEVAR in the acute (Group A) or subacute phase (Group SA) from January 2012 to October 2016 were included in the study. The change in aortic lumen (A), true lumen (TL), false lumen (FL), and true lumen index (TLi) at different levels were analyzed.

RESULTS

There was no statistically significant difference in the clinical information and morphologic imaging findings in Groups A and SA. At proximal levels (levels A-C), there was no difference in aortic remodeling parameters, that is, increased TL, decreased FL, and increased TLi at levels B and C and stable A at levels A-C, in both groups. Moreover, the above parameters were illustrated using a box-and-whisker plot, which revealed the unstable acute phase by the larger distribution interval and the median and abnormal values of the right skew distribution in Group A.

CONCLUSION

Postoperative surveillance is important for patients of both acute and subacute AD.

Endovascular management of acute aortic dissection

Acute dissection of the thoracic aorta is a potentially life-threatening condition which requires collaborative treatment from multiple specialties for optimal patient outcomes. Dissections involving the ascending aorta and aortic arch have traditionally been managed entirely by surgery, while dissections beyond the arch vessels have most commonly been relegated to medical management. This algorithm has been undergoing a paradigm shift over the past two decades due to improvements in stent graft technology, better understanding of the hemodynamic interactions of the true and false lumen and their influence on organ and limb perfusion, and improvements in medical management and long term surveillance for dissection-related complications. This manuscript includes a brief discussion of the pathogenesis and etiology of dissection, followed by an in-depth review of the medical and endovascular techniques utilized to treat patients afflicted by this condition.

Aortic Dissection Limited to Abdominal Aorta: an Underrecognized Entity?

BACKGROUND

Aortic dissection limited to the abdominal aorta is a rare clinical entity with non-specific clinical features. Optimal treatment, as well as natural history and progression of the disease, remain unclear. In 1992 we -reported 5 cases of isolated abdominal aortic dissection (IAAD) and in the present paper we update our series with 5 additional patients. A concise literature review is also provided.

METHODS

Between 1992 and 2014, we diagnosed 5 patients with IAAD (4 men, mean age 60.6 years, range 45-77). No patient presented with acute onset of symptoms. One patient was diagnosed with a periumbilical bruit, and diagnosis was made with magnetic resonance (MR)-angiography. Other diagnoses were incidental findings on computed tomographic (CT) scanning. Dissection was located infrarenally in four cases and at the celiac trunk in one case.

RESULTS

All cases were treated conservatively with hypertension control and close follow-up. Follow-up period ranged from 10 months to 20 years and was performed yearly by CT- or MR-angiography and blood pressure monitoring. All patients remained symptom-free, all dissection lengths remained stable. Slowly increasing post-dissection aneurysmal dilatation was encountered in two patients. We combined results of these five new patients with five previously diagnosed and reported patients at our center. Treatment was surgical in only one out of 10 patients. There was no disease-related mortality during follow-up.

CONCLUSIONS

Based on our case series, IAAD remains a rare clinical condition with relative benign clinical course. Treatment was almost exclusively conservative. Recent publications state IAAD might be underrecognized and under-diagnosed compared to thoracic aortic dissections.

Management of acute aortic dissection

A new appraisal of the management of acute aortic dissection is timely because of recent developments in diagnostic strategies (including biomarkers and imaging), endograft design, and surgical treatment, which have led to a better understanding of the epidemiology, risk factors, and molecular nature of aortic dissection. Although open surgery is the main treatment for proximal aortic repair, use of endovascular management is now established for complicated distal dissection and distal arch repair, and has recently been discussed as a pre-emptive measure to avoid late complications by inducing aortic remodelling.

First-line beta-blockers versus other antihypertensive medications for chronic type B aortic dissection

BACKGROUND

Thoracic aortic dissection (TAD) is a severe and often lethal complication in people with hypertension. Current practice in the treatment of chronic type B aortic dissections is the use of beta-blockers as first-line therapy to decrease aortic wall stress. Other antihypertensive medications, such as calcium channel blockers (CCBs), angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs), have been suggested for the medical therapy of type B TAD.

OBJECTIVES

To assess the effects of first-line beta-blockers compared with other first-line antihypertensive drug classes for treating chronic type B TAD.

SEARCH METHODS

We searched the Database of Abstracts of Reviews of Effects (DARE) for related reviews. We searched the Hypertension Group Specialised Register (1946 to 26 January 2014), the Cochrane Central Register of Controlled Trials (2014, Issue 1), MEDLINE (1946 to 24 January 2014), MEDLINE In-Process, EMBASE (1974 to 24 January 2014) and ClinicalTrials.gov (to 26 January 2014).

SELECTION CRITERIA

We considered randomized controlled trials (RCTs) comparing different antihypertensive medications in the treatment of chronic type B TAD to be eligible for inclusion. Total mortality rate was the primary outcome of this review. Secondary outcomes included total non-fatal adverse events relating to TADs and number of people not requiring surgical treatment.

DATA COLLECTION AND ANALYSIS

Two review authors (KC, PL) independently reviewed titles and abstracts and decided on studies to include based on the inclusion criteria. We resolved discrepancies between the two review authors by discussion.

MAIN RESULTS

After a thorough review of the search results, we identified no studies that met the inclusion criteria.

AUTHORS' CONCLUSIONS

We did not find any RCTs that compared first-line beta-blockers with other first-line antihypertensive medications for the treatment of chronic type B TAD. Therefore, there is no RCT evidence to support the current guidelines recommending the use of beta-blockers. RCTs are required to assess the benefits and harms of beta-blockers and other antihypertensive medications as first-line treatment of chronic type B TAD.