Open surgical repair for chronic type B aortic dissection: a systematic review

Patient-Specific Haemodynamic Analysis of Virtual Grafting Strategies in Type-B Aortic Dissection: Impact of Compliance Mismatch

INTRODUCTION

Compliance mismatch between the aortic wall and Dacron Grafts is a clinical problem concerning aortic haemodynamics and morphological degeneration. The aortic stiffness introduced by grafts can lead to an increased left ventricular (LV) afterload. This study quantifies the impact of compliance mismatch by virtually testing different Type-B aortic dissection (TBAD) surgical grafting strategies in patient-specific, compliant computational fluid dynamics (CFD) simulations.

MATERIALS AND METHODS

A post-operative case of TBAD was segmented from computed tomography angiography data. Three virtual surgeries were generated using different grafts; two additional cases with compliant grafts were assessed. Compliant CFD simulations were performed using a patient-specific inlet flow rate and three-element Windkessel outlet boundary conditions informed by 2D-Flow MRI data. The wall compliance was calibrated using Cine-MRI images. Pressure, wall shear stress (WSS) indices and energy loss (EL) were computed.

RESULTS

Increased aortic stiffness and longer grafts increased aortic pressure and EL. Implementing a compliant graft matching the aortic compliance of the patient reduced the pulse pressure by 11% and EL by 4%. The endothelial cell activation potential (ECAP) differed the most within the aneurysm, where the maximum percentage difference between the reference case and the mid (MDA) and complete (CDA) descending aorta replacements increased by 16% and 20%, respectively.

CONCLUSION

This study suggests that by minimising graft length and matching its compliance to the native aorta whilst aligning with surgical requirements, the risk of LV hypertrophy may be reduced. This provides evidence that compliance-matching grafts may enhance patient outcomes.

Outcomes of Complex Endovascular Treatment of Post-Dissection Aneurysms

OBJECTIVE

Reports of endovascular treatment of chronic post-dissection aneurysms are limited to high volumes centres, posing questions about generalisability.

METHODS

All endovascular repairs of intact pararenal and thoraco-abdominal aneurysms in the Vascular Quality Initiative from 2014 to 2021 were studied, and peri-operative and long term outcomes were compared between repairs of degenerative and post-dissection aneurysms. Peri-operative outcomes were compared using mixed effects logistic regression, and long term outcomes using Medicare linkage.

RESULTS

There were 123 patients who completed treatment for post-dissection aneurysms and 3 635 for degenerative aneurysms, with 36% of post-dissection repairs and 6.7% of degenerative repairs performed in a staged fashion (p < .001). The majority (84%) of post-dissection aneurysms were extensive thoraco-abdominal aneurysms (TAAAs: Crawford Type 1, 2, 3, 5), compared with 22% of degenerative aneurysms (p < .001). Physician modified endografts were the primary repair type for post-dissection (73%), while commercially available fenestrated grafts were the dominant repair for degenerative (48%). The first stage of staged procedures was associated with a 2.8% peri-operative mortality rate, 5.1% spinal cord ischaemia, and 8.9% thoraco-abdominal life altering events (the composite of peri-operative death, stroke, permanent spinal cord ischaemia, and dialysis). Th final stage procedure and fluoroscopy times were similar, but technical success was lower in post-dissection repairs (75% vs. 83%, p = .018), both due to issues with the main endograft or bridging vessels (11% vs. 6.6%, p = .055), and types 1and 3 endoleak at completion (17% vs. 10%, p = .035). In addition, high volume surgeons had two fold higher odds of technical success than their low volume counterparts. Adjusted peri-operative outcomes were similar between pathology types, including when comparisons were restricted to extensive TAAAs. Crude and adjusted three year survival were similar, but three year re-interventions were significantly higher following post-dissection repairs (p < .001).

CONCLUSION

Complex endovascular repair of chronic post-dissection aneurysms is feasible but is associated with high rates of re-interventions and non-trivial rates of lack of technical success. More data are needed to evaluate the long term durability of these procedures, and the utility of centralising these complex procedures.

Does adjuvant hepatic artery infusion chemotherapy improve patient outcomes for hepatocellular carcinoma following liver resection? A meta-analysis

BACKGROUND

Adjuvant hepatic artery infusion chemotherapy (HAIC) has been shown to be beneficial to the patient outcomes in hepatocellular carcinoma (HCC).

METHODS

Randomized controlled trials (RCTs) and non-RCTs were identified from six databases up to January 26, 2023. Patient outcomes were assessed using overall survival (OS) and disease-free survival (DFS). Data were presented as hazard ratios (HR, 95% confidence intervals, or CIs).

RESULTS

The present systematic review included 2 RCTs and 9 non-RCTs with a total of 1290 cases. Adjuvant HAIC improved OS (HR of 0.69; 95% CI of 0.56-0.84; p < 0.01) and DFS (HR of 0.64; 95% CI of 0.49-0.83; p < 0.01). Subgroup analysis showed that HCC patients with portal vein invasion (PVI) or microvascular invasion (MVI) benefit from adjuvant HAIC in terms of OS ((HR of 0.43; 95% CI of 0.19-0.95; p < 0.01) and (HR of 0.43; 95% CI of 0.19-0.95; p = 0.0373), respectively) and DFS ((HR of 0.38; 95% CI of 0.21-0.69; p < 0.01) and (HR of 0.73; 95% CI of 0.60-0.88; p = 0.0125), respectively). Adjuvant HAIC with the oxaliplatin-based approach significantly improved OS (HR of 0.60; 95% CI of 0.36-0.84; p = 0.02) and (HR of 0.59; 95% CI of 0.43-0.75; p < 0.01), respectively).

CONCLUSION

This meta-analysis demonstrated that postoperative adjuvant HAIC was beneficial in HCC patients with PVI and MVI. It remains unclear whether HAIC can improve the survival outcome in all HCC patients after hepatic resection.

MicroRNAs and drug resistance in colorectal cancer with special focus on 5-fluorouracil

Colorectal cancer is globally one of the most common cancers in all age groups. The current chemotherapy combinations for colorectal cancer treatment include 5-fluorouracil-based regimens; however, drug resistance remains one of the main reasons for chemotherapy failure and disease recurrence. Many studies have determined colorectal cancer chemoresistance mechanisms such as drug efflux, cell cycle arrest, DNA damage repair, apoptosis, autophagy, vital enzymes, epigenetic, epithelial-mesenchymal transition, stem cells, and immune system suppression. Several microRNAs affect drug resistance by regulating the drug resistance-related target genes in colorectal cancer. These drug resistance-related miRNAs may be used as promising biomarkers for predicting drug response or as potential therapeutic targets for treating patients with colorectal cancer. This work reviews and discuss the role of selected microRNAs in 5-fluorouracil resistance and their molecular mechanisms in colorectal cancer.

A single-center experience in the use of hybrid techniques for thoracic aortic pathology

The hybrid method of treating thoracic aortic pathology is devoid of the disadvantages of traditional open surgery and, at the same time, has a broader range of applications than the endovascular method. From 2014 to 2019, we researched 122 patients with thoracic aortic pathology treated with the hybrid method (open surgery with thoracic endovascular aortic repair (TEVAR) at the National M. Amosov Institute of Cardiovascular Surgery National Academy of Medical Science of Ukraine. In the general group, 34 patients had a descending aortic aneurysm without dissection or rupture; 71 patients had an aortic dissection (10 - acute, 9 - subacute, 52 - chronic), penetrating aortic ulcer (PAU) - 7, thoracoabdominal aneurysm (Crawford I-II) - 4, isolated aortic arch aneurysm - 2, residual enlargement aorta after previous ascending aortic grafting causing type A acute aortic dissection (TAAD) - 3, primary aortic thrombosis - 1. Patients admitted as elective surgery candidates had switched aortic arch vessels (debranching) in the first stage and TEVAR in the second stage. For emergencies (aortic rupture with uncontrolled bleeding, malperfusion syndrome), TEVAR operation was performed first. Long-term results of treatment after three and six months are satisfactory. The hybrid technique of aortic arch treatment using modern minimally invasive technologies can eliminate the pathology in the most dangerous segment of the main artery of the body, providing a reasonable level of hospital mortality - 4.2%, and a small number of neurological complications.

Endovascular versus open surgical repair for complicated chronic Type B aortic dissection

BACKGROUND

Type B aortic dissection can lead to serious and life-threatening complications such as aortic rupture, stroke, renal failure, and paraplegia, all of which require intervention. Traditionally, these complications have been treated with open surgery. Recently however, endovascular repair has been proposed as an alternative.

OBJECTIVES

To assess the effectiveness and safety of thoracic aortic endovascular repair versus open surgical repair for treatment of complicated chronic Type B aortic dissection (CBAD).

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, and AMED databases, as well as the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers, to 2 August 2021. We searched references of relevant articles retrieved through the electronic search for additional citations.

SELECTION CRITERIA

We considered all randomised controlled trials (RCTs) and controlled clinical trials (CCTs) assessing the effects of thoracic aortic endovascular repair (TEVAR) versus open surgical repair (OSR) for treatment of complicated chronic Type B aortic dissection (CBAD). Outcomes of interest were mortality (all-cause, dissection-related), neurological sequelae (stroke, spinal cord ischaemia/paresis-paralysis, vertebral insufficiency), morphological outcomes (false lumen thrombosis, progression of dissection, aortic diameters), acute renal failure, ischaemic symptoms (visceral ischaemia, limb ischaemia), re-intervention, and health-related quality of life.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all titles and abstracts identified by the searches to identify those that met the inclusion criteria. From title and abstract screening, we did not identify any trials (RCTs or CCTs) that required full-text assessment. 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 evidence using GRADE.

MAIN RESULTS

We did not identify any trials (RCTs or CCTs) that met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

Due to lack of RCTs or CCTs investigating the effectiveness and safety of TEVAR compared to OSR for patients with complicated CBAD, we are unable to provide any evidence to inform decision-making on the optimal intervention for these patients. High-quality RCTs or CCTs addressing this objective are necessary. However, conducting such studies will be challenging for this life-threatening disease.

[Hybrid treatment of a patient with dissecting thoracoabdominal aortic aneurysm and single kidney]

Presented herein is a clinical case report regarding a repeat intervention for a type II dissecting thoracoabdominal aortic aneurysm treated by means of a hybrid technique in a 76-year-old male patient with a single kidney, having 9 years previously endured resection of an aneurysm of the infrarenal aortic portion. The first stage consisted in prosthetic repair of the thoracoabdominal aortic aneurysm by an oblique anastomosis, with the second stage (7 days thereafter) being endoprosthetic repair of the descending thoracic aorta. The findings of check-up computed tomography at 16 months postoperatively demonstrated no negative dynamics.

Mid-Term Results of Frozen Elephant Trunk Technique for Chronic Aortic Dissection

Objective: In this study, we report our experience using the frozen elephant trunk (FET) technique for chronic aortic dissection. Methods: Between January 2011 and December 2017, 15 patients underwent total arch replacement (TAR) with the FET technique for chronic aortic dissection (CAD). Results: Hospital mortality was 6.7% (n=1). No patients experienced spinal cord injury. Distal stent-induced new entry (dSINE) occurred in the early postoperative period in one patient. There were four unplanned additional operations to manage dSINE. Five patients suffered from dSINE, and aortoesophageal fistula developed in three of them. Short insertion length of the FET and large angle between the distal edge of the FET and the descending aorta were significantly more common in the dSINE group than in the non-dSINE group. The cumulative survival rates at 1, 3, and 5 years were 93.3%, 93.3%, and 66.4%, respectively. The cumulative aortic event-free rates at 1, 2, and 3 years were 85.7%, 77.1%, and 52.9%, respectively. Conclusion: The FET technique for CAD provided good early results. Short insertion length of the FET, however, can induce dSINE, which requires an additional operation at mid-term. Thus, surgical indication of the FET technique for CAD must be discussed.

Reversed Elephant Trunk Technique for the Repair of Type B Aortic Dissection: A Case Report

We report a case of a type B aortic dissection with an aneurysm treated by the replacement of the proximal descending thoracic aorta via the reversed elephant trunk technique. A 48-year-old asymptomatic man was diagnosed with a type B aortic dissection, moderate aortic regurgitation, and a good biventricular function in March 2012. Four years later (April 2016), a contrast-enhanced computed tomography examination revealed an aneurysmal dilatation in the patient's descending thoracic aorta with a thrombosis in the proximal part of the false lumen, which warranted surgical repair. He underwent type B aortic dissection repair through the left posterolateral thoracotomy. Three months after the surgery, the patient developed a type A aortic dissection with severe aortic regurgitation, which was successfully managed via a Bentall procedure with arch replacement facilitated by the reversed elephant trunk technique performed during the initial surgery through thoracotomy. At 2 years follow-up, the patient was doing well with a normal left ventricular function.

Early and midterm outcomes of endovascular treatment for chronic aneurysmal aortic dissection: a retrospective study

BACKGROUND

The aim of this study was to evaluate endovascular treatment for enlarged Stanford type B chronic aneurysmal aortic dissection (CAAD). The conventional treatment for CAAD is open repair; however, the operative mortality is high in extensive prosthetic graft replacements.

METHODS

A retrospective single-center study was conducted on 74 consecutive patients who underwent endovascular treatment for CAAD in the past 8.5 years. In the partial exclusion (PE) group, entry sites in close proximity to the maximum diameter of CAAD were closed using a stent graft and reentry sites were left without closure. In the complete exclusion (CE) group, we attempted to close all entry and reentry sites.

RESULTS

A total of 43 patients (PE group) and 31 patients (CE group) were included with mean ages of 59 and 63 years, respectively. Operative mortalities of 2.3% and 0% were observed in the PE and CE groups, respectively. Complete tear closure was successful in 17 of 31 patients (54.8%) in the CE group. In the PE group, complete thrombosis of the false lumen was achieved in only one case (2.3%). Freedom rates from reentry closure were 90.2%, 86.9%, and 78.2% at 1, 3, and 5 years, respectively. The diameter of the true lumen/aorta changed from 16.9/62.9 mm to 30.2/53.6 mm and from 13.7/55.1 mm to 25.8/51.0 mm in the aortic arch and descending thoracic aorta, respectively. The freedom rates from secondary intervention in successful and unsuccessful CE cases were 92.9% and 69.1%, respectively, at 1 year and 92.9% and 53.7%, respectively, at 3 years.

CONCLUSION

Endovascular treatment for CAAD had favorable early and midterm outcomes.

Conservative management versus endovascular or open surgery in the spectrum of type B aortic dissection

Background

Type B aortic dissection is a life-threatening acute aortic condition often with acute ischemic signs or symptoms. With initial management focusing on alleviating malperfusion and pain, and avoiding propagation of dissection or rupture both systolic blood and pulse pressure should be reduced initially by an aggressive medical approach. In the setting of persistent signs of complications endovascular strategies have replaced open surgery and led to a fourfold increase in early survival and better long-term outcomes.

Methods

An electronic health database search was performed on articles published between January 2006 and July 2017. Publications were included in this review if (I) the index aortic pathology was type B aortic (distal) dissection; (II) when medical management, open surgical replacement or thoracic endovascular aortic repair were among those options; (III) when at least one of all basic outcome criteria such as survival, spinal cord ischemia and cerebrovascular accident was reported; (IV) when ≥15 serial patients were included. A total of 62 studies were eligible and analysed.

Results

Our manuscript has summarized data collected over 12 years on management specific outcomes in the setting of distal aortic dissection and provides an up-to-date interpretation of the published evidence. For complicated cases, treated acutely, the 30-day or in-hospital mortality was 7.3% when managed by endovascular means, whereas the pooled rate for 30-day or in-hospital mortality was 19.0% when subjected to open repair. For acute uncomplicated type B dissection usually treated with blood pressure lowering medications, the pooled 30-day or in-hospital mortality rate was 2.4%. Survival rates at 5 years averaged at 60% (40% mortality). Freedom from any aortic event ranged from 34.0% to 83.9%, underlining an inherent risk of progression and late complications. For chronic complicated type B dissection, the rates of stroke, paraplegia and operative mortality following endovascular repair ranged from 5% to 13%, 2% to 13% and 2 to 13%, respectively, while 5-year survival rates after open repair ranged from 60% to 90%. In chronic uncomplicated type B dissection almost 90% of patients survive initial hospitalization and were subjected to medical management with a 5-year survival of 50-80%. However, up to 20-55% of medically treated patients develop aneurysmal degeneration after 5 years with an unknown risk of rupture.

Conclusions

Currently, the less invasive strategy of endovascular repair (as compared to open surgery) provides improved 30-day or in-hospital survival in the setting of complicated acute type B aortic dissection and may seek broad application. Open surgical aortic reconstruction should be left to experienced aortic centres if endovascular management is not an option.

Regenerative therapies increase survivorship of avascular necrosis of the femoral head: a systematic review and meta-analysis

PURPOSE

The aim of this study was to document the available evidence on the use of regenerative techniques for the treatment of femoral head osteonecrosis (or avascular necrosis of femoral head, AVN) and to understand their benefit compared to core decompression (CD) alone in avoiding failure and the need for total hip replacement (THR).

METHODS

The search was conducted on three medical electronic databases according to PRISMA guidelines. The studies reporting number and timing of failures were included in a meta-analysis calculating cumulative survivorship with a Kaplan-Mayer curve. Moreover, the results on failures in treatment groups reported in RCT were compared with those documented in control groups, in order to understand the benefit of biological therapies compared to CD for the treatment of AVN.

RESULTS

Forty-eight studies were included in this systematic review, reporting results of different types of regenerative techniques: mesenchymal stem cell implantation in the osteonecrotic area, intra-arterial infiltration with mesenchymal stem cells, implantation of bioactive molecules, or platelet-rich plasma. Overall, reported results were good, with a cumulative survivorship of 80% after ten year follow-up, and better results when regenerative treatments were combined to CD compared to CD alone (89.9% vs 70.6%, p < 0.0001).

CONCLUSION

Regenerative therapies offer good clinical results for the treatment of AVN. The combination of CD with regenerative techniques provides a significant improvement in terms of survivorship over time compared with CD alone. Further studies are needed to identify the best procedure and the most suitable patients to benefit from regenerative treatments for AVN.

How should we manage type B aortic dissections?

Dissection of the descending aorta is a serious and potentially lethal event. Treatment options consist of medical therapy, open surgical replacement of the affected aorta and thoracic endovascular repair. In acute cases, medical treatment is started initially. When complicated, endovascular repair is generally considered as first choice treatment, except for connective tissue disorders where open surgery remains the standard. In stable, uncomplicated patients with risk factors for future aortic growth pre-emptive endovascular repair should be considered in the sub-acute phase of the dissection. The treatment strategy in chronic dissections is somewhat debated. Long-term results and aortic remodeling of endovascular repair are disappointing and open surgery remains the standard.

Thoracoabdominal aortic replacement for Crawford extent II aneurysm after thoracic endovascular aortic repair

BACKGROUND

The surgical treatment of Crawford extent II aneurysms after thoracic endovascular aortic repair (TEVAR) remains challenging, because of the need to remove the failed endograft and the complexity of the aortic reconstruction. We retrospectively reviewed our experience with surgical management of Crawford extent II aneurysms after TEVAR using thoracoabdominal aortic replacement (TAAR).

METHODS

Eleven patients (10 males, 1 female) with Crawford extent II aneurysm after TEVAR were treated with TAAR between August 2012 and May 2015. The indications included: diameter >5.0 cm; persistent pain; size increase >0.5 cm/year; and no suitable landing zone for re-TEVAR. Five patients underwent surgery under deep hypothermic cardiac arrest, two under mild hypothermic cardiopulmonary bypass, and four under direct aortic cross-clamping under normothermia. Two patients had Marfan syndrome.

RESULTS

There were no in-hospital deaths. Continuous renal replacement therapy was required in three patients. One patient needed re-intubation, and two patients had prolonged intubation (>72 h). One patient sustained paraplegia after surgery but recovered during follow-up. Cerebrospinal fluid drainage were used in four patients (3 immediately in the operation room, and 1 in the intensive care unit when the patient suffered paraplegia). One patient died during follow-up.

CONCLUSIONS

TAAR represents a feasible option for the treatment of Crawford extent II aneurysms after TEVAR, with acceptable surgical risks and favorable results.

[Endovascular versus conventional vascular surgery - old-fashioned thinking? Part 1: interventions on the aorta]

Endovascular therapy has widely replaced conventional open vascular surgical reconstruction. For this reason both techniques were widely considered to be competing approaches. Evidence-based data from randomized prospective trials, meta-analyses and clinical registries, however, demonstrated that both techniques should be used to complement each other. It became increasingly more evident that the use of either procedure depends on the underlying disease and the anatomical conditions, whereby a combination of both (hybrid approach) may be the preferred option in certain situations. This review focuses on the treatment of complicated acute type B aortic dissection, descending thoracic aortic aneurysms, thoracoabdominal aortic aneurysms as well as asymptomatic and ruptured abdominal aortic aneurysms.

Efficacy and Optimal Timing of Endovascular Treatment for Type B Aortic Dissection

OBJECTIVES

To determine the efficacy and the optimal timing of thoracic endovascular aortic repair (TEVAR) for closing the primary entry in uncomplicated patients with chronic type B aortic dissection and a patent false lumen (FL).

METHODS

Thirteen patients underwent TEVAR for aortic dissection between 2008 and 2012. These patients had chronic dissection with a patent FL and expansion of the aorta. Early TEVAR was performed for five patients within 1-7 months from the index dissection (TEVAR-EC group) and delayed TEVAR was performed for eight patients within 1-16 years (TEVAR-DC group). Changes in the diameters and volumes of the true lumen (TL) and FL and the aortic remodeling were assessed by multidetector computed tomography for 3 years after TEVAR.

RESULTS

The reduction rate of FL in the thoracic aorta was notably higher in the TEVAR-EC group than in the TEVAR-DC group regardless of the presence or absence of distal retrograde flow. There was a significant TL expansion despite different timings of TEVAR.

CONCLUSIONS

Early TEVAR resulted in good prognosis and preferable aortic remodeling in uncomplicated patients with chronic type B aortic dissection and a patent FL, and we recommend early TEVAR within seven months after the index dissection.

Systematic review and meta-analysis: techniques and a guide for the academic surgeon

With the rapidly growing literature across the surgical disciplines, there is a corresponding need to critically appraise and summarize the currently available evidence so they can be applied appropriately to patient care. The interpretation of systematic reviews is particularly challenging in cases where few robust clinical trials have been performed to address a particular question. However, risk of bias can be minimized and potentially useful conclusions can be drawn if strict review methodology is adhered to, including an exhaustive literature search, quality appraisal of primary studies, appropriate statistical methodology, assessment of confidence in estimates and risk of bias. Therefore, the following article aims to: (I) summarize to the important features of a thorough and rigorous systematic review or meta-analysis for the surgical literature; (II) highlight several underused statistical approaches which may yield further interesting insights compared to conventional pair-wise data synthesis techniques; and (III) propose a guide for thorough analysis and presentation of results.