The frozen elephant trunk: seeking a more definitive treatment for acute type A aortic dissection.

OBJECTIVES: Conventional treatment for type A aortic dissection includes replacement of the ascending aorta with an open distal anastomosis in the hemiarch position. The frozen elephant trunk (FET) is a hybrid technique that extends the repair to the descending thoracic aorta. The goal is to improve resolution of malperfusion syndrome and to induce positive aortic remodelling and reduce the need for reintervention on the downstream aorta. We aim to summarize the data on the short and long-term outcomes of this technique. METHODS: A thorough search of the literature was conducted isolating all articles dealing with aortic remodelling after the use of FET in case of type A acute aortic dissection. Keywords 'aortic dissection', 'frozen elephant trunk', 'aortic remodelling' and 'false lumen thrombosis' were used. Data for type B and chronic aortic dissections were excluded. RESULTS: FET use favourably influences aortic remodelling. The main advantages lie in the exclusion of distal entry tears in either the aortic arch or descending aorta thus restoring antegrade blood flow in the true lumen and inducing false lumen thrombosis. False lumen thrombosis is not only induced at the level of the stent deployment but also lower in the distal descending aorta. Moreover, it offers an adequate landing zone in the mid-descending aorta for second-stage endovascular or open surgical aortic repair, if needed. CONCLUSIONS: FET can be advantageous in the treatment of acute type A aortic dissection dealing with extended aortic pathology.

Anomalous circumflex artery: a benign variant generating a malignant potential after valve surgery.

Coronary artery anomalies are a diverse group of congenital disorders presenting with highly variable clinical manifestations. The anomalous origin of left circumflex artery from the right coronary sinus following a retro-aortic trajectory is a well-recognized anatomic variation. Despite its benign course, it can prove lethal in association with valvular surgery. When single aortic valve replacement or combined with mitral valve replacement is performed, the aberrant coronary vessel may be compressed by or between the prosthetic rings triggering postoperative lateral myocardial ischemia. If left untreated, the patient is at risk of sudden death or myocardial infarction with its detrimental complications. Skeletonization and mobilization of the aberrant coronary artery is the most widely accepted intervention, but valve downsizing or concomitant surgical or transcatheter revascularization have also been described. However, large series are lacking from the literature. Therefore, no guidelines exist. This study is a thorough review of the literature concerning the aforementioned anomaly in association with valvular surgery.

Ascending Aorta Dissection Before 5.5 cm Diameter; "It Wasn't Raining When Noah Built the Ark".

INTRODUCTION: The aim of this study was to compare mean maximum ascending aortic diameter at the time of acute aortic dissection with the current surgical threshold for elective ascending aortic operations on non-syndromic thoracic aortic aneurysms. MATERIAL AND METHODS: All consecutive non-syndromic adult patients admitted for acute type A aortic dissection in a single tertiary centre were prospectively enrolled from April 2020 to March 2021. The primary endpoint was the difference between mean maximum aortic diameter at the time of dissection and the 5.5 cm threshold for elective repair. Secondary endpoints included 30-day/in-hospital mortality, aortic length and comparison with normal controls, length/height ratio index, "actual" preoperative Euroscore II and "predicted" Euroscore II if electively operated. RESULTS: Among 31 patients ageing 67.3±12.03 years on average, mean maximum aortic diameter at the time of dissection was 5.13±0.66 cm, significantly lower than the guidelines-derived surgical threshold of 5.5 cm (p=0.004). Mean aortic length was 11±1.47 cm, also significantly longer compared normal controls reported in the literature (p<0.001). The 30-day/in-hospital mortality was 35.5%. Mean length/height ratio index was 6.18±0.76 cm/m. Finally, mean "actual" preoperative Euroscore II was 10.43±4.07 which was significantly higher than the 1.47±0.57 "predicted" Euroscore II (p<0.05). CONCLUSIONS: The maximum aortic diameter at the time of acute type A aortic dissection of non-syndromic cases was significantly lower than the current recommendation for elective repair. Lowering of the current diameter-based surgical threshold of 5.5 cm may be profitable in terms of prevention, but further investigations should be undertaken. Length-based thresholds could also add to timely aortic dissection prevention.

Surgical Treatment of Pulmonary Embolism and Chronic Thromboembolic Pulmonary Hypertension.

Venous thromboembolism clinically presents as deep venous thrombosis or acute pulmonary embolism and is globally recognized as the third most frequent acute cardiovascular syndrome after myocardial infarction and stroke. Although pulmonary embolism does not typically cause severe pulmonary hypertension in the acute setting, thrombus organization and fibrosis can lead to stenosis or obliteration of pulmonary arteries in a minority of patients, which in turn result in severe pulmonary hypertension and right heart failure. This disease is labeled chronic thromboembolic pulmonary hypertension and can occur after a single episode or multiple ones of pulmonary embolism. The cornerstone of pulmonary embolism treatment is medical therapy, whereas systemic thrombolytic therapy has to be considered for patients with hemodynamic instability. Given the current acceptable short-term surgical mortality, the potential of first-line surgical embolectomy as an alternative to medical thrombolysis has gained momentum as far as pulmonary embolism treatment is concerned. In contrast to pulmonary embolism, bilateral complete pulmonary endarterectomy under short deep hypothermic circulatory arrest intervals is the treatment of choice against chronic thromboembolic pulmonary hypertension, given patients' operability. Pulmonary endarterectomy is suggested in every operable patient when the operation is offered by an experienced multidisciplinary team, including at least one experienced surgeon. Surgical embolectomy should also be limited to large institutions since it also requires an experienced heart team. This review concerns a thorough discussion regarding surgical treatment of pulmonary embolism and chronic thromboembolic pulmonary hypertension. Eligibility criteria, operation-related complications and postoperative outcomes are discussed in detail.

Dantrolene Induces Mitigation of Myocardial Ischemia-Reperfusion Injury by Ryanodine Receptor Inhibition.

The impairment of intracellular calcium homeostasis plays an essential role during ischemia-reperfusion injury. Calcium release from sarcoplasmic reticulum which is triggered by myocardial ischemia is mainly mediated by ryanodine receptors. Dantrolene sodium is a ryanodine receptor antagonist. The objective of the present study was to evaluate the in-vivo impact of dantrolene sodium on myocardial ischemia-reperfusion injury in swine models. An in vivo, experimental trial comparing 10 experimental animals which received dantrolene sodium with 9 control swine models was conducted. Their left anterior descending coronary artery was temporarily occluded for 75 minutes via a vessel tourniquet, which was then released. Myocardial reperfusion was allowed for 24 hours. Dantrolene was administered at the onset of the reperfusion period and levels of troponin, creatine phosphokinase and creatine kinase myocardial band between the two groups were compared. Additionally, various other hemodynamic parameters and left ventricular morphology and function were examined. There were significantly lower values of troponin, creatine phosphokinase and creatine kinase myocardial band in the dantrolene group indicating less ischemia-reperfusion injury. Moreover, the postischemic cardiac index was also greater in the dantrolene group, whereas viable myocardium was also better preserved. In conclusion, the in vivo cardioprotective role of dantrolene sodium against ischemia-reperfusion injury in swine models was indicated in this study. Therefore, dantrolene sodium administration could be a promising treatment against ischemia-reperfusion injury in humans. However, large randomized clinical studies should be firstly carried out to prove this hypothesis.

A modern approach to aortic valve insufficiency: Aortic root restoration via HAART 300 internal annuloplasty ring.

BACKGROUND AND AIM OF THE STUDY: HAART 300 is an internal geometric annuloplasty ring. The safety and efficacy of this novel device in aortic valve (AV) repair in a single referral center are reported. METHODS: Twenty patients with trileaflet AV insufficiency with ascending aorta and/or aortic root enlargement were included. Subannular implantation was performed to correct annular dilatation, whereas concomitant leaflet repair was performed whenever required. All but two patients also received ascending aorta replacement, whereas selective sinus replacement was performed in all but five patients. RESULTS: Follow-up was for a maximum of 3.8 years and a mean of 2.2 years. Mean age was 54.2 years old. Moderate to severe preoperative AV insufficiency was noted in 75% of patients, whereas 70% of them had an ascending aorta over 45 mm. One patient was lost from follow-up. Overall mortality as well as major complication rates were zero. Early postoperatively, no more than mild AV regurgitation was detected, whereas only one patient appeared with moderate AV regurgitation during our 2.2-year follow-up. New York Heart Association class was also significantly lower compared to preoperative values and valve gradients remained low at last follow-up. CONCLUSIONS: Geometric ring annuloplasty is a safe and effective valve sparing approach to deal with AV insufficiency contributing to overall root reconstruction. Short-term results are excellent rendering this easily reproducible and versatile method very attractive.

External flail chest stabilization; The simple, low-cost way.

Flail chest is a life-threatening clinical entity which can be complicated by respiratory insufficiency. Paradoxical motion of a part of chest wall is the basic cause to put the blame on. Consequently, stabilization of the chest wall is occasionally of paramount importance to achieve early extubation in a patient with post-trauma respiratory insufficiency. Hereby, a simple, low cost, harmless and effective approach of external stabilization is presented.

Perceval S valve empire: healing the Achilles' heel of sutureless aortic valves.

Aortic valve replacement is the treatment of choice concerning aortic valve disease. Excellent short- and long-term clinical results are reported. Patients referred for aortic valve replacement are getting older and older, so bioprosthetic valves play a more central role worldwide. However, patient comorbidities are also increased more often rendering patients unsuitable for open conventional aortic valve replacement. As a result, transcatheter aortic valve implantation has become the treatment of choice in patients at very high surgical risk. However, the percutaneous technique is related to major disadvantages provided that the diseased native valve is left in place. Its durability is also uncertain. More recently, sutureless Perceval S valve bioprosthesis has gained ground in the field of aortic stenosis therapy filling the gap between conventional aortic valve replacement and transcatheter approach. Excellent hemodynamic and clinical results are reported. Its deployment is performed under direct view and ischemic and overall operative times are significantly decreased. Five-year follow-up results are also optimal. However, the "Achilles' heel" of sutureless technology is increased rates of postoperative permanent pacemaker implantation requirement compared to conventional approach. The incidence of this complication varies in literature. Patient-related factors such as preoperative conduction disorders, older age and short membranous septum are predictors of postoperative pacemaker requirement. However, several technical modifications regarding manufacturer recommendations can be adopted to mitigate this complication. Appropriate annular decalcification, higher guiding sutures placement, reduced balloon pressure and duration and avoiding of oversizing can contribute to prevent from this complication.

Congenital, acquired, or both? The only two congenitally based, acquired heart diseases.

Discrete subaortic stenosis (DSS) is a type of left ventricular outflow tract obstruction whereas double-chambered right ventricle is a form of right ventricular outflow tract obstruction. Both of these cardiac malformations share lots of similar characteristics which classify them as acquired developmental heart diseases despite their congenital anatomical substrate. Both of them are frequently associated to ventricular septal defects. The initial stimulus in their pathogenetic process is anatomical abnormalities or variations. Subsequently, a hemodynamic process is triggered finally leading to an abnormal subaortic fibroproliferative process with regard to DSS or to hypertrophy of ectopic muscles as far as double-chambered right ventricle is concerned. In many cases, these pathologies are developed secondarily to surgical management of other congenital or acquired heart defects. Moreover, high recurrence rates after initial successful surgical therapy, particularly regarding DSS, have been described. Finally, an interesting coexistence of DSS and double-chambered aortic ventricle has also been reported in some cases.

Aortocoronary saphenous vein graft aneurysm misdiagnosed as aortic arch aneurysm.

Coronary artery bypass grafting is the mainstay of revascularization worldwide. However, the most widely used saphenous vein grafts are related to a number of late sequelae. Aortocoronary saphenous vein graft aneurysms mainly diagnosed incidentally are one of these complications. Although rare, given the fatal risk of rupture if left untreated, management either with percutaneous intervention or open redo surgery should be considered. However, no guidelines are established in current scarce literature. Hereby, we present the successful percutaneous management of a huge saphenous vein graft aneurysm via coiling, avoiding the risks of repeat sternotomy.

Elective replacement of the ascending aorta: is the 5.5-cm threshold appropriate? The insidious, small aorta.

OBJECTIVES: As thoracic aortic aneurysm disease continues to cause significant morbidity and mortality in the general population, the cardiovascular community continues the search for the golden threshold of elective surgical replacement of the ascending aorta. METHODS: Thoracic aortic aneurysm is a common disease, classified within the 20 most common causes of death in patients over 65 years old. Once aortic complications like dissection or rupture occur, they can prove fatal. Prophylactic surgical replacement of the ascending aorta remains the mainstay of treatment to prevent these complications. Current American and European guidelines agree that the threshold for the diameter for elective replacement of the ascending aorta in non-syndromic, asymptomatic aneurysmal disease is 5.5 cm. Overall, aortic dissection is related to poor prognosis, thus making early intervention paramount. RESULTS: There is a critical size above which the risk of dissection or rupture becomes extremely high. However, a significant post-dissection increase in diameter is reported, thus rendering the predissection aortic diameter well below the current threshold for elective surgical replacement of the ascending aorta. Moreover, it is widely reported that the majority of acute aortic dissections would not meet the criteria for prophylactic surgery prior to dissection. Additionally, elective surgical ascending aortic replacement in the current era shows a significantly improved risk-benefit ratio, which justifies a more aggressive approach in the management of aortic aneurysmal disease. CONCLUSIONS: As a result, there is a lot of discussion in the literature about the requirement of a leftward shifting of the surgical threshold for elective aortic replacement.

Epicardial cardioverter defibrillator implantation due to post-fontan ventricular tachycardia.

Long-term survival of patients submitted to a Fontan procedure is reduced because of arrhythmias. Late post-Fontan ventricular tachycardia is extremely rare, but it can be fatal. Consequently, the implantation of an implantable cardioverter defibrillator may be required. The implantation of such a device after a Fontan operation can be rather difficult due to anatomic reasons that exclude transvenous approach. Epicardial ICD implantation is a treatment option for these patients. Transatrial approach, shock ICD coils placement in azygos vein or directly in the pericardium are possible alternatives. We hereby present a successful epicardial implantable cardioverter defibrillator implantation in a post-Fontan 39-year-old man suffering from ventricular tachycardia.

Cardioplegic storage solution: Is it the guardian of saphenous vein graft endothelium?

INTRODUCTION: Despite their suboptimal long-term patency, saphenous vein grafts are the most widely used conduits to achieve complete revascularization during coronary artery bypass grafting (CABG). Although vein storage critically impairs endothelial integrity, contradictory data concerning optimal storage solutions exist. The aim of this study is to explore any in vitro impact of cardioplegic solutions and temperature on vein grafts endothelial integrity during their storage. MATERIALS AND METHODS: A single-center, prospective trial including 40 consecutive patients was conducted. Eligibility criteria included patients submitted to CABG receiving at least one vein graft. An excess segment of the graft was harvested and divided into four different parts. Each one of them was stored under different conditions; either in a conventional heparin-enriched blood solution or in a cardioplegic solution, at room temperature (20°C-22°C) and in the refrigerator (5°C). Endothelial integrity was evaluated via immunohistochemistry using an antibody against CD31. RESULTS: Endothelial integrity (measured in a scale from 1-worst to 5-best) was significantly better after cardioplegic solution storage (2.83 ± 0.15 and 3.10 ± 0.13 in cold and room temperature, respectively) compared with storage in conventional solutions (2.23 ± 0.16 and 2.0 ± 0.15 in cold and room temperature, respectively). A significant effect of cardioplegic storage solution, as well as of cold temperature and cardioplegic solution interaction on endothelial preservation was reported, whereas storage temperature did not prove a significant factor by its own. CONCLUSIONS: Cardioplegic storage solutions result in significantly better endothelial preservation compared with conventional heparin-enriched blood solutions. The association with superior clinical outcomes remains to be proved.

Editor's Choice - Cryopreserved Allografts for Arterial Reconstruction after Aorto-Iliac Infection: A Systematic Review and Meta-Analysis.

OBJECTIVE: Native and aortic graft infections are rare, but they represent one of the most life threatening complications of vascular surgery. Several materials and surgical approaches have been developed so far. Among them, cryopreserved allografts have been proposed as a treatment option. A systematic review and meta-analysis was conducted to investigate the role of cryopreserved allografts for arterial reconstruction after aorto-iliac infection. METHODS: The current meta-analysis was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Patient baseline characteristics were investigated, along with 30 outcomes after use of cryopreserved arterial allografts for reconstruction after aorto-iliac infection. Pooled proportions with 95% CIs of outcome rates were calculated. RESULTS: A total of 31 studies, including 1,377 patients, finally participated in the meta-analysis. Among the early outcomes, 30 day mortality was 14.91% (95% CI 11.78-18.31). Peri-anastomotic rupture/allograft disruption rate was 5.90% (95% CI 2.77-9.88), while pooled aneurysmal degeneration/allograft dilatation was 4.99% (95% CI 1.60-9.68). A pooled rate of 3.11% (95% CI 1.60-4.98) was estimated for pseudoaneurysm formation after the use of cryopreserved arterial allografts, while the allograft thrombotic/stenotic complication rate and peri-anastomotic infection were 12.19% (95% CI 7.90-17.15) and 3.32% (95% CI 1.90-5.03), respectively. Mortality during follow up was 19.24% (95% CI 11.97-27.58), while allograft related mortality during follow up was 3.58% (95% CI 1.56-6.15). A pooled allograft related re-operation rate was estimated at 24.87% (95% CI 17.89-32.51). CONCLUSIONS: The use of cryopreserved allograft seems to be a safe and durable option with acceptable outcomes for treatment of aorto-iliac infection.

Frozen Elephant Trunk: An Alternative Surgical Weapon Against Extensive Thoracic Aorta Disease. A Three-Year Meta-Analysis.

BACKGROUND: Conventional open total arch replacement is the treatment of choice for surgical aortic arch pathologies. However, it is a two-stage procedure related to high cumulative and interval mortality rates. Hybrid type III aortic arch reconstruction, the so-called "frozen elephant trunk" is a one-stage alternative approach. METHODS: A meta-analysis and detailed review of the literature published from January 2013 until December 2016, concerning frozen elephant trunk hybrid approach was conducted and data for morbidity and mortality rates were extracted. RESULTS: Among 989 patients included, the pooled 30-day or in-hospital mortality rate was 5.04% (95%CI=1.13-10.74), stroke rate was 2.38% (95%CI=0.13-6.30), and the irreversible paraplegia due to spinal cord injury rate was 0.63% (95%CI=0.00-2.73). Finally, the pooled cumulative survival at 1year was remarkably high (86.7%, 95%CI=81.08-92.90). CONCLUSIONS: Frozen elephant trunk is a safe alternative to conventional elephant trunk repair for extensive aortic arch pathologies with acceptable short- and mid-term results, avoiding the interval mortality hazard.