Aortic Annuloplasty: Focus on the Use of an External Teflon Ring

Aortic annuloplasty has been clearly demonstrated to have a protective influence in aortic valve repair. Over the past 20 years, different annuloplasty concepts have been proposed by different groups. However, the most appropriate approach to enable long-term annular stability remains highly controversial. The aim of this article is to give a general overview of all types of aortic annuloplasty, particularly focusing on the use of an external Teflon ring, as proposed by our group. In this technique, external root dissection is performed in the same fashion as for reimplantation; the only difference is that it is necessary to go below the coronary ostia take-off. A series of pledgeted sutures (usually between 6 and 9 sutures) are placed at the level of the virtual basal ring. The external ring is made using a Teflon strip with a length of 8 to 9 cm, to reduce the annulus to a diameter of between 21 and 23 mm. The sub-annular sutures are then passed at the appropriate level through the Teflon strip and the strip is parachuted outside the aortic root base, passing under the coronary ostia. The two ends of the Teflon strip are tied at the level of the non-coronary sinus. Aortic annuloplasty is a crucial step to improve valve competence and stabilization. While several techniques offer good mid- to long-term results, annuloplasty with an external Teflon ring appears to be a simple and effective alternative to guarantee stable root diameters. Longer follow-up studies are needed to confirm the mid- to long-term results.

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.

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.

The percutaneous coronary angioplasty gets better, but the surgical coronary artery bypass does not stay behind

Coronary artery bypass grafting remains one of the most frequently performed cardiac operations, with well-established prognostic benefits in patients with multivessel coronary artery disease and left main disease. Despite an increasingly higher patients’ risk profile, the results of this procedure have significantly improved over time, with an evident and striking decrease in operative mortality and peri-operative complications. A fair amount of technical and technological refinements has further improved the short- and long-term results of coronary artery bypass surgery. The improvements in the beating heart coronary surgery and aortic ‘no-touch’ technique, in the appropriate use of conduits (bilateral internal mammary artery, radial artery, and composite conduits configuration), and in the optimization of venous grafts’ patency are reviewed.

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

Objective

Methods

Results

Conclusions

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.

OUP accepted manuscript

Cardiac myxoma is the most common primary benign cardiac tumor in adults and right atrial myxoma is a rare observation. We report a case of a 56-year-old woman who presented with dyspnea and diagnosed with a right atrial myxoma. Urgent operation through a right mini thoracotomy was done and myxoma was completely excised. Traditionally, median sternotomy with cardiopulmonary bypass is used for excision of cardiac myxoma. Excision through a mini thoracotomy for patients with right atrial myxoma appear to be safe, feasible and efficacious.

Giant Distal Anastomotic Pseudoaneurysm 35 Years after Bentall Operation Mimicking an “Elephant Trunk”

We present the case of a giant distal aortic pseudoaneurysm 35 years after a classic mechanical Bentall operation. Computed tomography and coronary angiography showed that this originated from the distal suture line. The proximal suture and coronary ostia appeared to be intact. At reoperation, we found a complete dehiscence of distal suture line: the graft was floating in the pseudoaneurysm, mimicking an “elephant trunk” procedure. This complication suggested a systematic and accurate follow-up of patients who underwent an original Bentall procedure.

[The completion Bentall procedure: aortic root and ascending aorta replacement after prior aortic valve replacement]

We describe the case of a patient with an ascending aorta and aortic root aneurysm who underwent aortic valve replacement, 14 years earlier, with a mechanical prosthesis, which was normally functioning at time of reoperation. We describe the "completion Bentall" technique - a modified Bentall technique -, a procedure for prosthesis-sparing aortic root replacement. This technique simplifies the original procedure in reinterventions, reducing complication rates and aortic cross-clamping and cardiopulmonary bypass times, with a good surgical result.

The Skirt and Collar of The Valsalva Graft: One Dress Fits All

In the original pre-formed Valsalva graft, the skirt is the defining feature. It is a self-expanding portion, obtained by 90° rotation of the Dacron fabric corrugation with respect to the rest of the graft. Due to this manufacturing feature, the skirt length is equal to the graft diameter and, once pressurized, it expands by 25-30% (up to 10 mm) from the nominal size. Proximal to this bulged portion, a small collar completes the prosthesis. By virtue of this anatomical design, the Valsalva graft is recommended for most aortic root surgeries including valve-sparing and Bentall procedures. The skirt, by recreating the pseudo-sinuses, represents the key feature of the graft when used for aortic valve-sparing procedures (remodeling and reimplantation). However, in the Bentall procedure, the graft collar is an important feature because it is useful to attach the Valsalva graft to the valve prosthesis sewing ring when making a valved conduit. Moreover, once the graft is pressurized, the whole volume of the skirt better accommodates the struts and the leaflets of biological and mechanical prostheses. Furthermore, the expanded skirt reduces the distance and the tension on the coronary button anastomosis, increasing safety and possibly reducing complication rates. This review demonstrates the versatility of the Valsalva graft in various scenarios of aortic root surgery, with special emphasis on different uses of the skirt and the collar.

Optimized use of the "skirt" of the Valsalva graft for the completion Bentall

We report the case of a patient with an aortic root aneurysm who had previously undergone aortic valve replacement with a large mechanical prosthesis which proved to be normally functioning at the time of reoperation. We describe a new technique of replacing the aortic root while retaining the existing aortic valve similar to the "completion Bentall" procedure using a 32 mm Valsalva graft by suturing the skirted portion of the graft to the sewing ring of the mechanical valve. The ability of the skirt to increase its diameter was the key of this approach.

Fate of a coronary artery intramural haematoma complicating aortic root surgery: a case report

Background

Coronary intramural haematoma (CIH) is an uncommon but potentially life-threatening complication during aortic root surgery (such as Bentall procedure). Depending on its extension it can lead to cardiogenic shock. Documented reports of this complication are lacking in literature.

Case summary

In the report we present a case of CIH and its management and we show a stepwise imaging of the healing process that gives an insight of the fate of CIHs.

Discussion

This case raises awareness of CIH as differential diagnosis for myocardial ischaemia during aortic root surgery. It underlines the effectiveness of immediate surgical revascularization, highlights the potential temporary role of coronary artery bypass graft that can stabilize the acute coronary syndrome and may give time to the CIH to reabsorb and native coronary circulation to re-establish.

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.

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.

Biological solutions to aortic root replacement: valve-sparing versus bioprosthetic conduit

Composite valve graft implantation described by Bentall and De Bono is a well-documented technique of aortic root replacement used for a large spectrum of pathologic conditions involving the aortic valve and the ascending aorta. While mechanical valves were initially used, biological prostheses were later introduced in order to avoid long-term anticoagulation and its related complications. The increasing age of patients who undergo aortic root surgery, and data supporting the use of a biological aortic valve in the younger population, have significantly increased the need for a composite biological valved conduit. However, parallel to the increased use of biological valve in the context of a Bentall operation, aortic valve-sparing (AVS) operation have also been performed in a growing number of patients. Sarsam and David described the remodeling and the reimplantation procedures more than 25 years ago with the aim of sparing otherwise normal aortic valves in the presence of a root aneurysm. Important achievements in this discipline have occurred over the past decade including development and refinement of valve preserving aortic root replacement techniques, development of a classification system for aortic insufficiency, surgical approaches to cusp disease with different cusp anatomy. Both procedures can now provide excellent root reconstruction and adequate clinical results in terms of late valve durability. The AVS technique offers several advantages over the Bentall procedure, such as no need for oral anticoagulation and lifestyle adjustments. AVS operations have become established alternatives to Bentall procedures for patients with aortic root pathology. However, data comparing the safety and durability of these approaches are lacking.

The combined role of sinuses of Valsalva and flow pulsatility improves energy loss of the aortic valve

OBJECTIVES

Normal aortic valve opening and closing movement is a complex mechanism mainly regulated by the blood flow characteristics and the cyclic modifications of the aortic root. Our previous in vitro observations demonstrated that the presence of the Valsalva sinuses, independently from root compliance, is important in reducing systolic pressure drop across the aortic valve. This in vitro study was designed to ascertain if this effect is dependent on the flow characteristics.

METHODS

Stentless 21, 23 and 25 mm aortic prostheses were sutured inside Dacron graft with and without sinuses. Hydrodynamic performance of the root models was investigated in steady-state (continuous) and unsteady-state (pulsatile) flow regimes. Aortic transvalvular pressure drop and effective orifice area (EOA) were evaluated.

RESULTS

The continuous flow analysis revealed that no marked differences in pressure drop characterized the two root configurations at flow regimes lower than 15 l/min, independently of valve size. Conversely, at higher flow regimes (up to 30 l/min) a relatively low pressure drop continued to characterize grafts with sinuses, whereas marked increments in pressure drop were measured in straight grafts, especially in the smaller size (77.05 ± 4.58 vs 23.80 ± 2.44 mmHg; 18.40 ± 1.31 vs 7.66 ± 0.37 mmHg and 29.54 ± 0.17 vs 7.12 ± 0.07 mmHg, for 21, 23 and 25 mm valve, respectively). Under pulsatile conditions, the presence of sinuses clearly confirmed lower pressure drops also more evident in the smaller valve sizes (53.89 ± 1.06 vs 11.6 ± 0.24 mmHg at 7 l/min for 21 mm valve). EOA values were always lower in the absence of sinuses. In continuous flow regimes, at 30 l/min EOA of 25 mm valve size was 3.67 ± 0.02 cm(2) in the Valsalva model versus 1.79 ± 0.01 cm(2) for the Straight model. In pulsatile tests, at 7 l/min a 25-valve size demonstrated an EOA of 5.47 ± 0.60 in the Valsalva model versus 2.50 ± 0.02 cm(2) in the Straight model.

CONCLUSIONS

These findings (i) confirm the hypothesis that the sinuses of Valsalva play a key role in optimizing the aortic haemodynamics during systole, minimizing energy losses; (ii) suggest that the sinuses of Valsalva are needed because of the complex nature of blood flow during ejection.

Long-term results of the valve reimplantation technique using a graft with sinuses

OBJECTIVE

Aortic valve reimplantation is the most commonly used technique to spare the aortic valve. Long-term results data are scarce and available only with the use of standard straight graft. We examined the long-term results of reimplantation of the aortic valve using a graft incorporating sinuses of Valsalva.

METHODS

From May 2000 to December 2014, 124 patients had an aortic valve reimplanted into a graft with sinuses of Valsalva. The mean age was 53 ± 13 years and the majority were men (87%). Marfan syndrome was present in 21 patients (17%) and 12% had a bicuspid valve. Patients were prospectively followed by means of transthoracic echocardiography. The mean follow-up was 63 ± 52 months.

RESULTS

Overall survival at 5, 10, and 13 years was 94.4% ± 2.2%, 90.5% ± 4.4%, and 81.4% ± 7.3%, respectively. Six patients required reoperation within a time frame of 6 to 96 months. None of the patients died at reoperation. Freedom from reoperation was 95.4% ± 2.3% at 5 years and 90.1% ± 4.3% at 10 and 13 years. All patients who needed reoperation had surgery during the first 5 years. Three patients had residual aortic insufficiency >2. Considering also all patients who underwent reoperation because of aortic insufficiency, freedom from moderate to severe residual aortic insufficiency was 94.1% ± 2.6% at 5 years, and 87.1% ± 4.7% at 10 and 13 years.

CONCLUSIONS

The majority of patients who had their valve reimplanted in a graft with sinuses continue to perform well after 10 years.

Intraaortic migration of an epicardial pacing wire: percutaneous extraction

Infrequent but serious complications have been described in association with temporary epicardial pacing wires. We describe the case of an intraaortic migration of an infected retained atrial temporary epicardial pacing wire and the transfemoral percutaneous interventional approach for its extraction.

Annular dilatation and loss of sino-tubular junction in aneurysmatic aorta: implications on leaflet quality at the time of surgery. A finite element study

OBJECTIVES

In the belief that stress is the main determinant of leaflet quality deterioration, we sought to evaluate the effect of annular and/or sino-tubular junction dilatation on leaflet stress. A finite element computer-assisted stress analysis was used to model four different anatomic conditions and analyse the consequent stress pattern on the aortic valve.

METHODS

Theoretical models of four aortic root configurations (normal, with dilated annulus, with loss of sino-tubular junction and with both dilatation simultaneously) were created with computer-aided design technique. The pattern of stress and strain was then analysed by means of finite elements analysis, when a uniform pressure of 100 mmHg was applied to the model. Analysis produced von Mises charts (colour-coded, computational, three-dimensional stress-pattern graphics) and bidimensional plots of compared stress on arc-linear line, which allowed direct comparison of stress in the four different conditions.

RESULTS

Stresses both on the free margin and on the 'belly' of the leaflet rose from 0.28 MPa (normal conditions) to 0.32 MPa (+14%) in case of isolated dilatation of the sino-tubular junction, while increased to 0.42 MPa (+67%) in case of isolated annular dilatation, with no substantial difference whether sino-tubular junction dilatation was present or not.

CONCLUSIONS

Annular dilatation is the key element determining an increased stress on aortic leaflets independently from an associated sino-tubular junction dilatation. The presence of annular dilatation associated with root aneurysm greatly decreases the chance of performing a valve sparing procedure without the need for additional manoeuvres on leaflet tissue. This information may lead to a refinement in the optimal surgical strategy.

Differences in aortic cusp coaptation between the reimplantation and the remodeling techniques of aortic valve-sparing surgery: an in vitro porcine model study

OBJECTIVES

We sought to evaluate the effects of the reimplantation type versus the remodeling type of aortic valve-sparing technique on the geometry of the same aortic root.

METHODS

Fifteen fresh isolated porcine hearts with normal aortic valves and a standard aortoventricular junction size of 23 mm were processed. An aortic valve-sparing replacement was performed by reimplanting the native aortic root inside a 28-mm Valsalva graft (Vascutek Ltd, Renfrewshire, UK). Hearts were subsequently implanted with instruments in a test circuit, and the aortic roots were pressurized at a fixed pressure of 100 mm Hg. Diameters of the aortoventricular junction, of the sinuses, and of the sinotubular junction, as well as effective height and coaptation height of aortic valve leaflets, were measured by echography. Transition from the reimplantation to the remodeling configuration was then achieved by longitudinally cutting the skirt of the graft from the annulus to the top of each commissure. The same measurements were then repeated.

RESULTS

After transition from the reimplantation to the remodeling configuration, significant increases in the sizes of the aortoventricular junction and of the sinuses were observed. Effective height and coaptation height significantly decreased, and the rounded cross-sectional profile of the aortic valve leaflets flattened.

CONCLUSIONS

In the same aortic root, transition from the reimplantation to the remodeling configuration of aortic valve-sparing surgery results in a significant increase in aortic root sizes and in a significant reduction of effective height and coaptation height, suggesting a less satisfactory result.

Role of the sinuses of Valsalva on the opening of the aortic valve

OBJECTIVE

The present in vitro study was designed to ascertain whether the presence of sinuses of Valsalva in the aortic root were able to regulate the valve effective orifice area and modulate the gradient across the valve independently from root compliance.

METHODS

Four different root configurations were prepared. Of the 4, 2 were silicon configurations with the same compliance, 1 with and 1 without sinuses of Valsalva, in which a 25-mm Solo stentless aortic valve was sutured inside. The other 2 configurations were obtained by substituting the upper part of the root with a straight Dacron graft or with a Valsalva graft in a remodeling fashion to reproduce the surgical situation. All roots were mounted in a pulse duplicator to measure the pressure decrease across the valve and effective orifice area at different cardiac outputs.

RESULTS

With increasing cardiac output up to 7 L/min, an increase in the pressure decrease across the valve was evident in both configurations without sinuses of Valsalva (7.90 ± 1.7 and 11 mm Hg ± 0.1 mm Hg, respectively) but not in those with sinuses (2.87 ± 0.5 and 2.42 mm Hg ± 0.5 mm Hg). Similarly, with increasing cardiac output, the effective orifice area increased significantly only in the roots with sinuses (5.13 ± 0.5 and 5.47 ± 0.5 vs 3.06 ± 0.3 and 2.50 cm(2) ± 0.02 cm(2), respectively).

CONCLUSIONS

When the cardiac output is increased to greater than the resting physiologic values, the presence of sinuses of Valsalva, independently of root compliance, prevents an increase in the pressure decrease across the valve by way of an increase of the effective orifice area.

Diastolic properties of the Sorin Solo, ATS 3F, Edwards Prima Plus and Medtronic Freestyle stentless valves: an independent in-vitro comparison

BACKGROUND AND AIM OF THE STUDY

Currently, little is known of the diastolic properties of stentless valves that affect stress and strain on leaflets and, hence, their durability. In a pressurized aortic root model, a series of in-vitro tests was conducted to determine how stentless valves behave in diastole, and how they adapt to different annulus-to-sinotubular junction (STJ) ratios.

METHODS

Sixteen 25 mm stentless aortic valves (four each of the Sorin Solo, ATS 3F, Edwards Prima Plus and Medtronic FreeStyle) were sutured into a 32 mm Valsalva graft, suspending the commissures into the expandable region (42 mm). The neoaortic root was pressurized and the size of the STJ progressively reduced by wrapping the neocommissural ridge with Dacron rings. Endoscopic views and ultrasound imaging were used to observe the geometry of the leaflets, regurgitation, and the height and level of leaflet coaptation at different annulus-to-STJ ratios.

RESULTS

Pericardial prostheses built to mimic a cylinder (ATS 3F and Sorin Solo) showed the greatest tolerance to STJ dilatation and a larger coaptation surface, but also a tendency to roll in on themselves in an italic S-shape if oversized. Valves built to mimic native aortic leaflets (porcine Prima Plus and Medtronic Freestyle) showed a reduced tolerance to STJ dilatation, resulting in regurgitation and a smaller coaptation surface, but also a reduced tendency to roll if oversized.

CONCLUSION

Despite similar systolic performances, stentless prostheses behave differently during diastole. The 3F and Solo valves benefit from a better tolerance to STJ dilatation, while the Prima Plus and Freestyle benefit from a more stable shape of closure under conditions of oversizing.

A method to avoid knot-tying in artificial chordae implantation for mitral valve repair

BACKGROUND AND AIM OF THE STUDY

Expanded polytetrafluoroethylene (ePTFE) neo-chordae implantation requires knot-tying inside the heart, which can be especially difficult if a minimally invasive approach is used. A system has been developed that allows the implantation of neo-chordae, without a need for knot-tying, in addition to a simultaneous and reversible length adjustment after the evaluation of valve continence using hydrostatic tests.

METHODS

The system consists of a suture with a needle at one end and a 20 mm pledgeted loop at the opposite end. The suture presents five stop-knots at constant (2 mm) intervals, starting 35 mm from the base of the loop. The suture is passed first through the leaflet, then through the papillary muscle, then inside a reversible noose-lace (cow-hitch) that is made on the loop. The noose-lace is closed under one of the knots of the suture coming from the papillary muscle. After closing the loop at a presumably optimal length, a hydrostatic test is performed. The chordal length can be modified by releasing the noose-lace and sliding it over another fixing-knot until an optimal distance is obtained.

RESULTS

Fourteen patients underwent repair with this technique. No deaths or major adverse events occurred. All patients underwent echocardiography at discharge, and again at six and 12 months after surgery. Thirteen patients had no residual insufficiency, and one patient had mild postoperative insufficiency but without progression of regurgitation at the sixth postoperative month.

CONCLUSION

This new technique facilitates artificial chordae implantation. The short-term results are satisfactory, but further follow up is required.

Double-arterial cannulation for aortic valve replacement with porcelain aorta

We describe a new technique of aortic valve replacement (AVR) in patients with porcelain aorta. Three patients (mean age 75 years) were treated. The cardiopulmonary bypass (CPB) was established after side-graft right axillary artery and direct femoral artery cannulation. Venous drainage was obtained by atrio-caval cannulation. The procedures were performed in mild hypothermia (30 degrees C). Cerebral perfusion was carried out by clamping the innominate artery and all epiaortic vessels. The aorta was endoclamped by a Foley balloon inserted into the isthmus. The aorta was then opened longitudinally for 10 cm to expose and replace the aortic valve. Near-infra-red spectroscopy (NIRS) and bilateral radial artery pressure were used to monitor effective cerebral perfusion. Operative mortality was absent. The mean time of CPB was 73 min. NIRS-derived tissue oxygenation was maintained above 55%. Postoperative course was uneventful. This technique has several advantages: first, the cannulation of right axillary and the common femoral artery allows simultaneous cerebral and systemic perfusion. Second, any form of cross-clamp is avoided and the aorta is occluded away from the epiaortic vessels. Third, there is an increased freedom to choose the best place for aortotomy.

Re-creation of a sinuslike graft expansion in Bentall procedure reduces stress at the coronary button anastomoses: A finite element study

OBJECTIVE

The Bentall procedure is routinely performed using a straight Dacron graft coupled with a mechanical or a biologic valve. Creation of coronary ostia buttons significantly reduces tension on the coronary anastomoses and consequently the incidence of pseudoaneurysm formation. We sought to evaluate if the use of a specifically designed graft with a sinuslike root portion that bulges out upon pressurization can reduce stress on coronary anastomoses. A finite element computer-assisted stress analysis was used to simulate these 2 different anatomic conditions and to analyze tension in computed tomographic scans obtained from patients operated on with either a straight or a "sinus" graft.

METHODS

Theoretical models of the procedures with finite element computer-aided design technique were created and tested with the Abaqus Standard Suite, verifying the pattern of stress and strain when a uniform pressure of 200 mm Hg was applied to the model. Next, using SimpleWare SCanIP technology, computed tomographic scans of patients having both procedures were used to obtain finite element mesh models. A uniform pressure of 200 mm Hg was then applied, and the distribution of stress and strain was analyzed.

RESULTS

Von Mises Charts are color-coded, computational, 3-dimensional stress-pattern graphics that show that stress around the coronary ostia in a standard straight graft model is nearly double compared with the model with sinuses (peak stress of 0.4 Mpa for the sinus model and 0.7 Mpa for the traditional straight model). In computed tomographic scan reconstructions, the stress contour is uniformly distributed in the graft with sinuses, and it is highly concentrated around the ostia in the straight graft. Accordingly, higher-peak stress values are registered in the straight configuration (1.8 MPa for the sinus graft and 2.5 MPa for standard graft).

CONCLUSION

Even though finite elements technique is necessarily a simplification of a real biologic environment, all tests seem to indicate that a standard tubular graft gives a higher stress to coronary sutures. Relieving the stress on the coronary anastomoses by using a graft with preformed sinuses of Valsalva may decrease the incidence of postoperative complications such as bleeding and late pseudoaneurysm formation.

Sorin Solo stentless valve: extended adaptability for sinotubular junction mismatch

Stentless valve continence is affected by the implantation technique, annular symmetry and dilatation of the sinotubular junction. We tested in vitro how the Sorin Solo stentless pericardial valve adapts to a slightly dilated sinotubular junction. Stentless Sorin Solo aortic valves (25 mm) were sutured into a 32-mm Valsalva graft suspending the commissures into the expandable region of the graft. The neo-aortic root was pressurized and sinotubular junction size progressively decreased by wrapping the neocommissural ridge with Dacron rings. Direct endoscopic view and ultrasound imaging were used to observe geometry and morphology of leaflets, regurgitation, height and level of leaflets coaptation. Fresh porcine valves of the same annular size were used as controls. Solo valves had mild regurgitation at baseline, became continent at 32 mm sinotubular junction size and remained continent at any size of reduction, with optimal coaptation height and level. Porcine valves had severe regurgitation at baseline, became continent at 30 mm and showed mild insufficiency and reduction of the coaptation level at a sinotubular junction of 28 mm. The Solo valve prevents residual valve regurgitation for a wider range of sinotubular junction mismatch when compared with natural porcine valves. This extended tolerance to sinotubular junction mismatch suggests a safe use of stentless valves even in suboptimal geometry roots.

Initial experience of an arterial shunt for bilateral antegrade cerebral perfusion during hypothermic circulatory arrest

PURPOSE

The purpose of this study is to describe an intravessel cerebral shunt that allows perfusion of both cerebral hemispheres through the axillary artery.

DESCRIPTION

The cerebral shunt is a 10-cm to 12-cm long cannula with a lumen for blood perfusion and two balloons, one at each distal end. The proximal balloon is adapted for retaining the proximal end of the catheter in the innominate artery; the second inflatable balloon is adapted for retaining the distal end of the catheter into the left common carotid artery.

EVALUATION

Three consecutive patients received bilateral brain perfusion through the right axillary artery with the use of this cerebral shunt.

CONCLUSIONS

The cerebral shunt allowed bilateral cerebral perfusion as verified with cerebral oximetry in the absence of any evident neurologic dysfunction.

Valsalva graft in the Bentall procedure: from mechanical valve to the BioValsalva, world's first biological aortic conduit

Aortic root replacement is the procedure of choice for patients with ascending aortic aneurysms and diseased aortic valve leaflets. The increasing age of patients who undergo aortic root surgery, and data that support the use of a biological aortic valve in the younger population, have significantly increased the need for a composite biological valved conduit. The third-generation Triplextrade (Terumo Vascutek, Renfrewshire, Scotland, UK) Dacron conduit with its three-layer technology, can be stored in glutaraldehyde along with biological prostheses while maintaining a complete blood impermeability. As the result of this fundamental improvement, the ready-to-use composite biological valved graft is currently available for the first time in different sizes, which avoids the need of assembling it on the surgical table. The procedure is expedited and a better hemostasis achieved because of the intrinsic characteristics of the new three-layered conduit. The BioValsalva (Terumo Vascutek, Renfrewshire, Scotland, UK) has been obtained by suturing a stentless aortic valve (Elan, Kohler, Leeds, UK) inside a Triplex Valsalva graft and combining the advantages of a biological valved conduit with the advantages of better leaflets dynamics, less tension on coronary ostia, and improved coronary flow proper of the Valsalva conduit. The authors' preliminary clinical experience with the BioValsalva is reported herein and the technique is discussed.

Sinotubular Junction Size Affects Aortic Root Geometry and Aortic Valve Function in the Aortic Valve Reimplantation Procedure: An In Vitro Study Using the Valsalva Graft

BACKGROUND

Sinotubular junction (STJ) size in aortic valve reimplantation procedures is usually predetermined on the basis of experience or intraoperative mathematical calculations. Given the small coaptation reserve of aortic valve leaflets, small errors can produce an incompetent aortic valve. We tested in vitro the effect of geometrically changing the relationship between aortic annulus size and STJ size on aortic root geometry and aortic valve function.

METHODS

Twenty-five-millimeter diameter scalloped porcine aortic roots were reimplanted into 32-mm Valsalva grafts (Vascutek, Renfrewshire, Scotland), suspending commissures into the expandable region of the graft itself. Neoaortic roots were pressurized up to 100 mm Hg. Sinotubular junction size was then changed by wrapping the neocommissural ridge with Dacron rings of decreasing size. Geometry of the aortic root, anatomy of aortic valve leaflets, and extent of their coaptation were analyzed by direct endoscopic view and by ultrasound imaging techniques.

RESULTS

Pressurizing unwrapped aortic root resulted in centrifugal displacement of commissures, aortic leaflets tethering and bending, and central aortic regurgitation. By reducing STJ size, coaptation height of aortic valve leaflets first increased to reach a maximum for an STJ size corresponding to 30 mm, and then decreased for further reduction of STJ size. Excess reduction of STJ size also resulted in prolapsed aortic leaflets and eccentric aortic regurgitation.

CONCLUSIONS

In the reimplantation procedure performed with a Valsalva graft, aortic valve function and leaflet coaptation can be optimized by optimizing STJ size.

A new method for artificial chordae length “tuning” in mitral valve repair: Preliminary experience

OBJECTIVES

Implanting expanded polytetrafluoroethylene neochordae is an established technique in treating complex mitral regurgitation. Difficulty in obtaining reliable preoperative and intraoperative measurements of an ideal neochordae length, as well as the unfeasibility of adjusting lengths once set in place with traditional techniques, led us to develop a system that allows rapid change of length after the evaluation of valve continence with hydrostatic tests.

METHODS

The system consists of two components: a papillary component with arrest knots at constant intervals and a leaflet component with a reversible noose-lace to fix the loop to 1 of the knots on the papillary component. After implantation and coupling of the two components at a presumable optimal length, a prosthetic ring is sutured in place. Hydrostatic testing is then performed. Optimal chordae length can be obtained by releasing the noose-lace and sliding it over another fixing-knot. The adjustment can be performed as often as required without placing stress on the anatomic structures.

RESULTS

Twenty patients underwent repair with this technique. No deaths or major adverse events occurred. All patients underwent echocardiography, both at discharge and 6 months after the operation. A total of 14 patients had no residual insufficiency, 5 patients had mild or trivial postoperative insufficiency without progression of regurgitation at the sixth month, and only 1 patient had mild insufficiency at discharge progressing to moderate insufficiency at the sixth month.

CONCLUSION

This new technique facilitates an otherwise complicated procedure. Short-term results are satisfactory, but further follow-up is required.

In vitro evaluation of aortic valve prosthesis in a novel valved conduit with pseudosinuses of Valsalva

OBJECTIVE

This study was undertaken to determine whether the presence of vortices immediately above a prosthetic aortic valve could negatively influence the in vitro hydrodynamic performances of a biologic or mechanical valve implanted in a new Dacron polyester fabric conduit that incorporates sculpted sinuses of Valsalva.

METHODS

With a computer-controlled pulse duplicator, the in vitro performance (pressure differences, closure and leakage volumes, and energy losses) of a 25-mm mechanical or biologic prosthesis implanted in a standard Dacron straight conduit or in the new Dacron graft with a sculpted sinus were analyzed and compared.

RESULTS

The mechanical and biologic prostheses at 7 L/min cardiac output showed pressure drops across the valve of 8.72 mm Hg and 13.45 mm Hg, respectively, when inserted in the new Valsalva-style graft and of 7.97 mm Hg and 12.94 mm Hg, respectively, when inserted in the standard graft. The closure and leakage volumes for mechanical valves were higher than those for biologic valves; however, the presence or absence of sinuses did not result in significant differences in closure and leakage volumes. The maximal total energy losses were 5.89% and 9.49% for mechanical and biologic valves, respectively. No differences were evident between the two different Dacron grafts for each prosthetic heart valve.

CONCLUSION

The normal opening and closing behavior of a prosthetic aortic valve was not altered or modified by a different root shape above the heart valve. The presence of vortices inside the pseudosinuses of Valsalva did not influence the hydrodynamic properties of the biologic and mechanical valves tested.

The effect of bilateral internal thoracic artery harvesting on superficial and deep sternal infection: The role of skeletonization

OBJECTIVE

To determine the relative risk of sternal dehiscence in patients undergoing bilateral internal thoracic artery harvesting and to assess whether and to what extent the technique of artery skeletonization might reduce this risk.

METHODS

Prospectively collected data on patients undergoing coronary artery bypass operations with at least a single internal thoracic artery were reviewed. The last 450 patients receiving bilateral internal thoracic artery grafts were compared with 450 patients who received a single internal thoracic artery during the same period. The left internal thoracic artery was always harvested in a pedicled fashion. Among patients receiving a bilateral internal thoracic artery, both arteries were harvested in a pedicled fashion in 300 cases, whereas both internal thoracic arteries were skeletonized in the remaining 150 cases.

RESULTS

Compared with a single internal thoracic artery, harvesting both internal thoracic arteries either in a skeletonized or in a pedicled fashion increased the chance of deep (1.1% vs 3.3% vs 4.7%; P = .01) or superficial (4.8% vs 7.8% vs 12%; P = .002) sternal infection. However, the technique of artery harvesting (odds ratio, 4.1; 95% confidence interval, 1.4-12.1); the presence of peripheral arteriopathy (odds ratio, 3.1; 95% confidence interval, 1.2-8.5), and resternotomy for bleeding (odds ratio, 8.2; 95% confidence interval, 2.0-33.6) were the only independent predictors for deep sternal infection, whereas the technique of artery harvesting (odds ratio, 3.0; 95% confidence interval, 1.6-5.4), female sex (odds ratio, 2.2; 95% confidence interval, 1.2-4.2), and diabetes (odds ratio, 1.7; 95% confidence interval, 1.0-2.9) were the only independent predictors of superficial sternal infection. In diabetic patients, there was no difference in the incidence of deep sternal infection among patients receiving a single internal thoracic artery or double skeletonized internal thoracic arteries ( P = .4).

CONCLUSIONS

Bilateral internal thoracic artery harvesting carries a higher risk of sternal infection than harvesting a single internal thoracic artery. Skeletonization of both internal thoracic arteries significantly decreases this risk. A strategy of bilateral thoracic artery grafting can also be offered to patients at high risk for wound infection.