Biological Valves Impervious to Calcification: Is this Holy Grail a Cup Ready to Drink?

An indefinitely lasting bioprosthesis that does not require anticoagulation treatment is the holy grail of substitutive heart surgery. However, this goal is not yet in sight with the present state of technology. Over the past few years, tremendous advances have been achieved regarding tissue anticalcification processes, hemodynamic performance and future-proofing by ensuring compatibility with transcatheter valve-in-valve procedures. The Inspiris Resilia valve (Edwards Lifesciences, Irvine, CA) was designed to incorporate all of these enhancements. It is now leaving the experimental phase and is being tested in the real world. We present here a comprehensive review of the evolution of biological prostheses, details of new anticalcification technologies, and early results of published studies as well as the experience at the European Hospital (Rome, Italy), the site of the first European implant and a leading center in various protocols. In our two years of experience with the Inspiris Resilia, there have been no cases of structural valve deterioration, endocarditis, detachment or periprocedural complication, and gradients seem to be superior to those with the previous generation of Edwards valves. While longer-term experience is clearly needed, the results thus far are encouraging.

External Stents for Vein Grafts in Coronary Artery Bypass Grafting: Targeting Intimal Hyperplasia.

INTRODUCTION: Progressive saphenous vein graft (SVG) failure remains a key limitation to the long-term success of coronary artery bypass grafting (CABG). SVG disease after the first year is dominated by intimal hyperplasia, which predisposes the SVG to thrombosis and accelerated atherosclerosis. The objective of this study was to review and summarize the latest experimental and clinical data on the use of mechanical external stents for vein grafts. METHODS: In January 2020, the PubMed database was searched using the terms "external stent", "CABG", "saphenous vein graft" and "intimal hyperplasia". The results were reviewed and only randomized experimental and clinical studies that analyzed the effect of external stenting on venous intimal hyperplasia were included in the analysis, together with studies that investigated the clinical benefit of external stenting. RESULTS: Eight experimental and four clinical trials met the search criteria. Controlled trials in different large animal models concluded that external stenting significantly reduced intimal hyperplasia 3-6 months post implantation, and reduced both thrombosis rates and the development of lumen irregularities. Data from randomized controlled trials with a follow-up period of 1-4.5 years supported the pre-clinical findings and demonstrated that external stents significantly reduced vein graft disease. CONCLUSION: Strong evidence indicates that supporting the vein with external stents is safe and leads to clear advantages at both the anatomical and cellular levels. With the further accumulation of consistent positive results, external stenting of SVG may become the standard of care in future CABG.

Latest Advances in Cardiac Valvular Replacement.

The original monograph on valvular prostheses in Surgical Technology International was published in 1993. It represents a milestone and a reference point for critically organizing information on a complex and rapidly evolving topic. The last update was published in 2010. Since then, there have been significant developments regarding both "traditional" surgical prosthesis and valves for transcatheter implantation. Both bioprostheses and mechanical prostheses continue to evolve with respect to both their design and materials to further optimize hemodynamics and prevent a patient-prosthesis mismatch. Each type of prosthesis has its own Achilles's heel: limited durability leading to structural failure for bioprostheses, and the need for anticoagulation for mechanical prostheses. After a long period of only marginal improvements, new techniques for tissue preservation and manufacturing seem to have placed surgeons on the verge of a minor revolution regarding bioprostheses. In addition, in the realm of mechanical prostheses, the many promises of silicon-free pyrolitic carbon still need to be confirmed, while an extremely cautious approach with new anticoagulants has left patients out of the non-dose-adjusted revolution, which has radically improved the quality of life of other patients, such as those suffering from atrial fibrillation. On the other hand, transcatheter therapies are maturing, and the next few years will probably see an even stronger shift in the treatment of patients away from surgical theaters to cath labs, or perhaps to a new mixed theater (which could lead to a new mixed surgeon/catheter expert professional). This paper provides device descriptions and images of the technologies that are considered to be predominant, at least for the moment, to help orient surgeons and to serve as a reference for students. This report would not have been possible without the prior work of Profs. Denton Cooley and Eric Jamieson.

European Initial Hands-On Experience with HEMOPATCH, a Novel Sealing Hemostatic Patch: Application in General, Gastrointestinal, Biliopancreatic, Cardiac, and Urologic Surgery.

Topical hemostatic agents that can seal tissues and assist in the coagulation cascade of patients undergoing surgery have been readily available for several decades. Using either synthetic or animal/plant-derived materials, these agents represent a powerful tool to reduce postoperative bleeding complications in cases where mechanical or energy-driven hemostasis is not possible or insufficient. Recently, a novel sealing hemostatic patch, HEMOPATCH (Baxter International, Deerfield, IL), was developed. The device is a thin and flexible patch consisting of a specifically-formulated porous collagen matrix, coated on one side with a thin protein-binding layer. This gives the patch a dual mechanism of action, in which the two components interact to achieve hemostasis by sealing off the bleeding surface and initiating the body's own clotting mechanisms. Here we present a series of case reports that outline the quick, effective hemostatic sealing of HEMOPATCH in a variety of clinical applications, including solid organ, gastrointestinal, biliopancreatic, endocrine, cardiovascular, and urologic surgeries. Essentially a feasibility study, these reports demonstrate how HEMOPATCH can be applied to seal almost any bleeding surface encountered during a range of procedures. Our results show that the device is eminently capable in both via laparotomy and laparoscopic approaches, and in patients with impaired coagulation or highly variable anatomies. In conclusion, our cases document the ease-of-use, application, and immediate hemostatic effect of the patch across a broad range of surgical settings and paves the way for future randomized clinical trials with more extensive follow-up.

Systematic adjustment of root dimensions to cusp size in aortic valve repair: a computer simulation.

OBJECTIVES: Aortic valve repair requires the creation of a normal geometry of cusps and aortic root. Of the different dimensions, geometric cusp height is the most difficult to change while annular and sinotubular dimensions can be easily modified. The objective of this study was to investigate, by computer simulation, ideal combinations of annular and sinotubular junction size for a given geometric height. METHODS: Based on a literature review of anatomical data, a computational biomechanics model was generated for a tricuspid aortic valve. We aimed to determine the ideal relationships for the root dimensions, keeping geometric height constant and creating different combinations of the annular and sinotubular junction dimensions. Using this model, 125 virtual anatomies were created, with 25 different combinations of annulus and sinotubular junction. Effective height, coaptation height and mechanical cusp stress were calculated with the valves in closed configuration. RESULTS: Generally, within the analysed range of geometric heights, changes to the annular diameter yielded a stronger impact than sinotubular junction diameter changes for optimal valve configuration. The best results were obtained with the sinotubular junction being 2-4 mm larger than the annulus, leading to higher effective height, normal coaptation height and lower stress. Within the range tested, stenosis did not occur due to annular reduction. CONCLUSIONS: In tricuspid aortic valves, the geometric height can be used to predict ideal post-repair annular and sinotubular junction dimensions for optimal valve configuration. Such an ideal configuration is associated with reduced cusp stress.

Twenty-year experience of aortic valve reimplantation using the Valsalva graft.

OBJECTIVES: Over the past 20 years, valve-sparing aortic root replacement has aroused increasing interest because of a progressive attitude towards the preservation of natural tissue. Aortic reimplantation is the most used technique to spare the valve, allowing simultaneously aortic root replacement and aortic annular stabilization. The reimplantation into a graft with sinuses guarantees an optimal anatomic and functional reconstruction with established good results at 15 years. The aim of this study is to report the world longest follow-up (up to 20 years) of aortic valve reimplantation using the Valsalva graft. METHODS: From February 2000 to December 2021, 265 consecutive patients with aortic root aneurysm received aortic valve reimplantation using the Valsalva graft. From 2018, leaflet plication with the routine use of calliper was performed. For each patient, we performed both intraoperative and post-procedural transoesophageal echocardiography. All patients were followed with clinical assessment and echocardiography. The mean duration of follow-up was 85 ± 63 months. RESULTS: The study cohort had a median age of 55 ± 18 and 87.2% were male. The aortic root aneurysm was associated to bicuspid aortic valve in 18.9% of patients and to Marfan syndrome in 10.6% of cases. 55.9% had an aortic regurgitation ≥ 2+. Overall survival at 15 was 87.6 ± 3.4. Freedom from cardiac death was stable at 99.6 ± 0.4 at 5, 10 and 15 years. Freedom from recurrent AR ≥3+ and freedom from reoperation remained stable at 10 and 15 years at 92.2 ± 2.1 and 95.9 ± 1.6, respectively. There was a minimal incidence of infective endocarditis (0.8%), thromboembolism (2.2%) and haemorrhage (2.0%). Six out of 7 patients requiring reoperation had surgery in the first period of our experience (last in 2004). Early suboptimal results had a negative effect on residual aortic regurgitation. Moreover, we hypothesized that the routine use of calliper may have contributed to a further improvement of the outcome, even if these data need to be confirmed by a longer follow-up. CONCLUSIONS: The first long-term follow-up after aortic valve reimplantation using the Valsalva graft demonstrated excellent results. These long-term results gradually improved with learning curve, remaining stable during the second decade of observation. The systematic use of calliper may have contributed to a further improvement of the outcome.

Patient Blood Management in Microsurgical Procedures for Reconstructive Surgery.

Introduction: The main purpose of reconstructive surgery (RS) is to restore the integrity of soft tissues damaged by trauma, surgery, congenital deformity, burns, or infection. Microsurgical techniques consist of harvesting tissues that are separated from the vascular sources of the donor site and anastomosed to the vessels of the recipient site. In these procedures, there are some preoperative modifiable factors that have the potential to influence the outcome of the flap transfer and its anastomosis. The management of anemia, which is always present in the postoperative period and plays a decisive role in the implantation of the flap, covers significant importance, and is associated with clinical and laboratory settings of chronic inflammation. Methods: Chronic inflammatory anemia (ACD) is a constant condition in patients who have undergone RS and correlates with the perfusion of the free flap. The aim of this treatment protocol is to reduce the transfusion rate by maintaining both a good organ perfusion and correction of the patient's anemic state. From January 2017 to September 2019, we studied 16 patients (16 males, mean age 38 years) who underwent microsurgical procedures for RS. Their hemoglobin (Hb) levels, corpuscular indexes, transferrin saturation (TSAT) ferritin concentrations and creatinine clearance were measured the first day after surgery (T0), after the first week (T1), and after five weeks (T2). At T0, all the patients showed low hemoglobin levels (average 7.4 g/dL, STD 0.71 range 6.2-7.4 g dL-1), with an MCV of 72, MCH of 28, MCHC of 33, RDW of 16, serum iron of 35, ferritin of 28, Ret% of 1.36, TRF of 277, creatinine clearance of 119 and high ferritin levels (range 320-560 ng mL-1) with TSAT less than 20%. All the patients were assessed for their clinical status, medical history and comorbidities before the beginning of the therapy. Results: A collaboration between the two departments (Department of Transfusion Medicine and Department of Reconstructive Surgery) resulted in the application of a therapeutic protocol with erythropoietic stimulating agents (ESAs) (Binocrit 6000 UI/week) and intravenous iron every other day, starting the second day after surgery. Thirteen patients received ESAs and FCM (ferric carboxymaltose, 500-1000 mg per session), three patients received ESAs and iron gluconate (one vial every other day). No patients received blood transfusions. No side effects were observed, and most importantly, no limb or flap rejection occurred. Conclusions: Preliminary data from our protocol show an optimal therapeutic response, notwithstanding the very limited scientific literature and data available in this specific surgical field. The enrollment of further patients will allow us to validate this therapeutic protocol with statistically sound data.

Reimplantation versus aortic ring annuloplasty in bicuspid valve with borderline aortic root ectasia.

Objective: Bicuspid aortic valve repair can be achieved with the reimplantation technique or external ring annuloplasty. Reimplantation could be an "overtreatment" in nonaneurysmatic aortic roots. External ring repair, on the contrary, could be an "undertreatment" in dilated roots. The aim of this retrospective study is to compare the 2 techniques in patients with borderline aortic root dimensions, analyzing early results, aortic regurgitation recurrence, and root dilation over time. Methods: We selected patients with bicuspid aortic valve and ectasia of the aortic root (40-48 mm) who underwent reimplantation or external ring repair. We compared the 2 techniques, analyzing immediate postoperative and follow-up echocardiography. Only patients with at least 1 year of follow-up were included. Results: We obtained 2 groups of 21 patients (reimplantation) and 22 patients (external ring). Median follow-up time was 36 (40) months. There were no deaths during the follow-up periods. Three patients required reoperation in the external ring group because of recurrent aortic regurgitation, with a freedom from reoperation of 77.8% at 7 years (no reoperation was required in the reimplantation group). In the external ring group, we observed an immediate postoperative root diameter reduction and no significative expansion during follow-up (+0.4 mm/year, P = .184). Conclusions: Excellent results of reimplantation technique are confirmed and stable over time. Root diameter seems to remain stable over time when external ring technique was performed. The greater incidence of reoperation after external ring could be due to the progressive learning curve (256 patients vs 52 patients). Longer follow-up studies are needed.

Mitral repair of myxomatous valves with simple annuloplasty: a follow-up up to 12 years.

OBJECTIVES: Diffuse myxomatous mitral valve degeneration (DMD) represents a challenge in the reparative mitral valve surgery. A subgroup of patients with symmetrical DMD can be effectively treated with a simple band-annuloplasty with good early and mid-term results. Here, we evaluate the long-term outcomes in terms of freedom from reoperation, recurrence of moderate or severe mitral regurgitation (MR) and overall survival. METHODS: Between April 2006 and December 2020, patients with DMD causing severe MR and the echocardiographic features of symmetrical bileaflet prolapse, central regurgitant jet(s), annular dilation and no chordal ruptures were treated using a simple annuloplasty with a semi-rigid band. These patients were prospectively collected and retrospectively analysed. RESULTS: Seventy-five patients were enrolled. The mean clinical follow-up time was 104 [standard deviation (SD): 43] months, and echocardiographic follow-up time was 95 (SD: 43) months. The mean age was 54 (SD: 15) years, and 56% were females. Long-term overall survival was 98.2% [standard error (SE): 1.8], 93.7% (SE: 4.7) and 93.7% (SE: 4.7) at 4, 8 and 12 years, respectively. The freedom from reoperation was 100% at 4 and 8 years and 94.1% (SE: 5.7) at 12 years. The freedom from recurrent moderate or severe MR was 98.3% (SE: 1.7), 98.3% (SE: 1.7) and 92.8% (SE: 5.5) at 4, 8 and 12 years, respectively. CONCLUSIONS: Mitral repair with the simple band-annuloplasty for the treatment of MR due to symmetrical DMD seems to be stable and effective in the long term.

Towards a better comprehension of acute mesenteric ischemia after cardiac surgery. An analysis of 33 patients.

BACKGROUND: Acute mesenteric ischemia (AMI) after cardiac surgery is a rare but serious complication associated to high mortality. The time of onset is the key point to correctly evaluate the clinical scenarios. METHODS: Data from adult patients who underwent laparotomy for AMI after elective or urgent cardiac surgery were reviewed (January 2005 - December 2019) to report their anatomoclinical features in relationship to time of onset. Early events (within 48 hours) were allocated to Group 1, whereas late onsets were allocated to Group 2. RESULTS: The incidence of risk factors for non occlusive mesenteric ischemia was higher in Group 1 (chronic renal failure 80% vs 38.8%, P <0.05, use of inotropes 60% vs 5.5%, P <0.01, early oligo-anuria requiring CRRT 80% vs 16.6%, P <0.01, prolonged ventilation 46.6% vs 5.5%, P <0.05), where a significative occurrence of postoperative de novo atrial fibrillation was noted in Group 2 (55% vs 5.5%, P <0.01). The number of patients who required bowel resection was proportionally higher in the Group 2. CONCLUSIONS: Two well distinct categories of AMI after cardiac surgery can be classified. The first consists of patients with well-known risk factors developing ischemia as a result of severe visceral hypoperfusion The second consists of patients with low comorbidity who experience late AMI as a consequence of "trigger events", mainly de novo atrial fibrillation. This classification may be useful to better alert the medical staff to the possibility of bowel ischemia at any time after cardiac surgery, promoting early diagnosis and treatment. KEY WORDS: Mesenteric ischemia, Cardiovascular pathology.

External stenting of vein grafts in coronary artery bypass grating: interim results from a two centers prospective study.

BACKGROUND: previous studies evaluating external stents for saphenous vein grafts (SVG) in CABG were limited to on-pump isolated CABG and single grafting technique with one external stent per patient. The objective of this prospective study was to evaluate the safety and the short-term performance of external stents in a heterogeneous group of patients who underwent on- and off-pump CABG, single and sequential grafting. METHODS: 102 patients undergoing CABG were enrolled in two centers. All patients received internal mammary artery to the left anterior descending artery and additional arterial and/or venous grafts. In each patient, at least one SVG was supported with an external stent. Grafts' patency and SVG lumen uniformity were assessed using CT angiography at a pre-defined time window of 6-12 months post procedure. All patients were prospectively followed-up via phone call and/or visit every 6 months for Major Adverse Cardiac and Cerebrovascular Events. RESULTS: 51 patients (50%) underwent off-pump CABG and 23 patients (23%) were grafted with bilateral internal mammary arteries. Each patient received one or more SVG grafted in a sequential technique (44%) or as a single graft (56%). All SVG were externally stented in 84% of patients and in 16% (n = 16) one SVG was stented and one remained unsupported. At 6-12 months, patency rates of LIMA, RIMA, externally stented SVG and none-stented SVG were 100, 100, 98 and 87.5% respectively. 90% of the externally stented SVG had uniform lumen compared to 37% of the non-stented SVG. Clinical follow-up was completed for all patients with a mean duration of 20 months (range 6-54 months). During follow up period, one patient experienced myocardial infarction due to occlusion of the LIMA-LAD graft and one patient experienced a transient ischemic attack. CONCLUSIONS: External stenting of SVG is feasible and safe in CABG setting which includes off pump CABG and sequential SVG grafting and associated with acceptable early patency rates. TRIAL REGISTRATION: Study was registered at ClinicalTrials.gov. NCT01860274 (initial release 20.05.2013).

Long-term follow-up of Bentall procedure using the Perimount bioprosthesis and the Valsalva graft.

OBJECTIVES: Bentall procedure is the gold standard for aortic root pathologies when valve repair is not feasible. The development of durable bioprosthetic valves and improved vascular conduits allowed the implementation of bioprosthetic composite grafts; hereby, we performed a retrospective analysis of long-term follow-up of Bentall procedure using the Valsalva graft and the Perimount Magna Ease prosthesis. METHODS: From June 2000 to March 2019, 309 patients received an aortic root and valve replacement with a bioprosthetic composite graft. The mean age was 69 ± 6.9 years, and the majority were men (88%); most of them were affected by aortic stenosis (86%) and the mean aortic root diameter was 48.6 ± 5.5 mm. RESULTS: Freedom from cardiac death was 76.8% [confidence interval (CI) 32.5-94.0] at 16 years. Freedom from thromboembolism, haemorrhage, structural valve deterioration and infective endocarditis was 98.2% (CI 96.0-98.9), 95.2% (CI 87.1-98.2), 87.5% (CI 63.2-97.1) and 79.6% (CI 45.3-95.6) at 16 years, respectively. Freedom from reoperation was 74.7% (CI 41.9-90.6). CONCLUSIONS: These data indicate that, in experienced centres, the Bentall procedure is a safe and effective intervention. This is the first long-term follow-up that analyses the results after implantation of a composite graft made with the Perimount Magna Ease aortic valve and the Valsalva graft.

A direct correlation between commissural orientation and annular shape in bicuspid aortic valves: a new anatomical and computed tomography classification.

OBJECTIVES: The shape of the aortic annulus is still under debate. Recent findings suggest a possible gradual spectrum of circularity from tricuspid aortic valves (TAVs), to type 1 bicuspid aortic valves (BAVs) to type 0 BAVs. BAVs have been recently classified in a symmetrical (type A), asymmetrical (type B) or very asymmetrical (type C) phenotype according to the commissural orientation (CO) (160°-180°, 140°-159° and 120°-139°, respectively). The aim of this study is to verify in BAVs the correlation between the aortic annular shape and the CO of valve cusps and to suggest a new anatomical and geometric classification of BAVs based on CO and annular shape. METHODS: We retrospectively selected 191 consecutive patients who underwent both electrocardiography-gated computed tomography scan of the aortic root and transthoracic echocardiography between January 2016 and June 2019. The population was divided into 2 groups: 54 BAVs and 137 TAVs. We analysed the subgroup of BAV patients and divided them into group A, group B and group C depending on the CO. The shape of the aortic annulus was considered 'circular' or 'elliptic' according to the ellipticity index (EI).We studied the possible correlation between CO and annular shape in BAVs. We also analysed the subgroup of TAV patients studying their annular shape and EI. RESULTS: After univariate linear regression, BAV patients showed a significant correlation between the CO and the EI (R = -0, 445, R2 = 0, 198, P = 0.001). As the CO decreases, the EI increases and approaches an elliptical shape. After grouping BAVs according to the CO, a mean EI of 1.10 ± 0.07 was found in group A, 1.13 ± 0.08 in group B, 1.18 ± 0.07 in group C, P = 0.0097 indicating a gradual spectrum of ellipticity with the decrease of CO. TAVs subgroup showed a mean EI of 1.27 ± 0.09, suggesting that the more the CO is reduced in BAVs, the more the annulus probably tends towards the very elliptical shape of TAVs. CONCLUSIONS: This study shows a linear correlation between CO and annular shape in BAVs. In particular, the aortic annulus follows a continuous spectrum of ellipticity depending on the CO. These findings lay the groundwork for a new anatomical classification of BAVs based on CO and annular shape.