Aortic Root Replacement With Stentless Porcine Xenografts: Early and Late Outcomes in 132 Patients

The Sutureless Biological Bentall Procedure: A New Technique to Create a Modular Valve-Conduit Construct

The Perceval sutureless valve (Corcym, Saluggia, Italy) has been effectively adopted by surgeons for the treatment of degenerative aortic valve stenosis. Its simplified true sutureless implantation technique has proven useful for minimally invasive cases, but the use of Perceval as part of more complex root replacement has not previously been described. We present a novel technical modification to the manufactured biologic Bentall, called the sutureless biological Bentall. This technique allows for a true modular valve-conduit construction that will simplify future reintervention.

Transcatheter valve-in-valve implantation for degenerated stentless aortic bioroots

Background

Open surgical repair of a failed valve-sparing aortic root replacement (VSARR) or stentless bioroot aortic root replacement (bio-ARR) entails significant operative risks. Whether valve-in-valve transcatheter aortic valve replacement (ViV-TAVR) is feasible in patients with a previous VSARR or stentless bio-ARR remains unclear, given lingering concerns about the ill-defined aortic annulus in these patients and the potential for coronary obstruction. We present our experience with patients who had a previous VSARR or stentless bio-ARR and underwent ViV-TAVR to repair a degenerated aortic valve with combined valvular disease, aortic insufficiency and aortic stenosis.

Methods

In this retrospective data review, we identified and analyzed consecutive patients with a previous VSARR or stentless bio-ARR who underwent ViV-TAVR between December 1, 2014 and August 31, 2019.

Results

ViV-TAVR was performed in twelve high-risk patients with previous VSARR or bio-ARR during the study period. Of these, seven received Medtronic Freestyle porcine stentless bioprosthetic aortic roots, three received homograft aortic roots, one underwent a Ross procedure and one underwent VSARR. ViV-TAVR restored satisfactory valve function in all patients, and technical success was 100%. No patient had more than mild regurgitation after implantation. No thirty-day mortality was seen. One patient had major bleeding after transapical access, one patient had a transient ischemic stroke, and one patient needed permanent pacemaker implantation. At a median last follow-up of 21.5 months (interquartile range, 9.0-69.0 months), all patients remained alive and had satisfactory valve function.

Conclusions

In this study, ViV-TAVR was a clinically effective option for treating patients with a failed stentless bio-ARR or previous VSARR. Short-term and intermediate-term results after these procedures were favorable. These findings may have important implications for treating high-risk patients with structural aortic root deterioration and call for better transcatheter heart valves that are suitable for treating aortic insufficiency.

Does BioGlue contribute to anastomotic pseudoaneurysm after thoracic aortic surgery?

BACKGROUND

Although bovine serum albumin-glutaraldehyde glue (BioGlue®) has been successfully used as a hemostatic adjunct in aortic surgical procedures, there are reports that it may lead to anastomotic pseudoaneurysm formation. We seek to examine if the use of BioGlue is associated with a high incidence of anastomotic pseudoaneurysm formation following surgical repair of thoracic aortic disease.

METHODS

We reviewed the medical records and follow-up computed tomography (CT) scans of patients from 2001 to 2015 in whom BioGlue was used during surgical repair of thoracic aortic disease to detect postoperative anastomotic pseudoaneurysm formation.

RESULTS

A total of 233 patients with BioGlue use were identified. Mean age was 63.5±14.0 years (median 66; range 14-88; 25-75%, IQR 54-74 years) and 149 were male (63.9%). Surgical indication was thoracic aortic aneurysm in 169 (72.5%) patients, aortic dissection in 49 (21.0%), intramural hematoma in 9 (3.9%), penetrating aortic ulcer in 3 (1.3%) and other in 3 (1.3%). Emergency/urgent surgery was performed in 68 cases (29.2%). Operative mortality was 7.3% (17/233). Re-exploration for bleeding and neurologic deficits occurred in 24 (10.3%) and 21 (9.0%) patients respectively. All operative survivors were followed (100%, 216/216) and CT follow-up was available in 81.9% (177/216) for a mean duration of 2.4 years (median 0.6; 25-75% IQR 0.2-3.6 years). Anastomotic pseudoaneurysm was detected in 1 patient (0.6%) at 3 years postoperatively. This was an elderly female with extremely frail tissues who underwent a reoperative ascending and arch replacement for dissection.

CONCLUSIONS

The use of BioGlue in thoracic aortic surgery was not associated with excess incidence of anastomotic pseudoaneurysm formation following surgical repair of thoracic aortic disease. Its use need not be discouraged on this basis.

Porcine models of muscular dystrophy

Duchenne muscular dystrophy is a progressive, fatal, X-linked disease caused by a failure to accumulate the cytoskeletal protein dystrophin. This disease has been studied using a variety of animal models including fish, mice, rats, and dogs. While these models have contributed substantially to our mechanistic understanding of the disease and disease progression, limitations inherent to each model have slowed the clinical advancement of therapies, which necessitates the development of novel large-animal models. Several porcine dystrophin-deficient models have been identified, although disease severity may be so severe as to limit their potential contributions to the field. We have recently identified and completed the initial characterization of a natural porcine model of dystrophin insufficiency. Muscles from these animals display characteristic focal necrosis concomitant with decreased abundance and localization of dystrophin-glycoprotein complex components. These pigs recapitulate many of the cardinal features of muscular dystrophy, have elevated serum creatine kinase activity, and preliminarily appear to display altered locomotion. They also suffer from sudden death preceded by EKG abnormalities. Pig dystrophinopathy models could allow refinement of dosing strategies in human-sized animals in preparation for clinical trials. From an animal handling perspective, these pigs can generally be treated normally, with the understanding that acute stress can lead to sudden death. In summary, the ability to create genetically modified pig models and the serendipitous discovery of genetic disease in the swine industry has resulted in the emergence of new animal tools to facilitate the critical objective of improving the quality and length of life for boys afflicted with such a devastating disease.

Long Term Outcomes Following Freestyle Stentless Aortic Bioprosthesis Implantation: An Australian Experience

BACKGROUND

The Freestyle stentless bioprosthesis (FSB) has been demonstrated to be a durable prosthesis in the aortic position. We present data following Freestyle implantation for up to 10 years post-operatively and compare this with previously published results.

METHODS

A retrospective cohort analysis of 237 patients following FSB implantation occurred at five Australian hospitals. Follow-up data included clinical and echocardiographic outcomes.

RESULTS

The cohort was 81.4% male with age 63.2±13.0 years and was followed for a mean of 2.4±2.3 years (range 0-10.9 years, total 569 patient-years). The FSB was implanted as a full aortic root replacement in 87.8% patients. The 30-day all cause mortality was 4.2% (2.0% for elective surgery). Cumulative survival at one, five and 10 years was 91.7±1.9%, 82.8±3.8% and 56.5±10.5%, respectively. Freedom from re-intervention at one, five and 10 years was 99.5±0.5%, 91.6±3.7% and 72.3±10.5%, respectively. At latest echocardiographic review (mean 2.3±2.1 years post-operatively), 92.6% had trivial or no aortic regurgitation. Predictors of post-operative mortality included active endocarditis, acute aortic dissection and peripheral vascular disease.

CONCLUSIONS

We report acceptable short and long term outcomes following FSB implantation in a cohort of comparatively younger patients with thoracic aortic disease. The durability of this bioprosthesis in the younger population remains to be confirmed.

Pseudoaneurysm formation after medtronic freestyle porcine aortic bioprosthesis implantation: a word of caution

BACKGROUND

A growing literature describes aneurysmal deterioration after implantation of the stentless porcine aortic Medtronic Freestyle bioprosthesis (MFB; Medtronic Inc, Minneapolis, MN), with some suggesting inadequate tissue fixation with immune response as a cause. However, disjointed reports make the significance of these findings difficult to interpret. We address this concern by aggregating available data.

METHODS

We reviewed institutional data, the Food and Drug Administration's Manufacturer and User Facility Device Experience registry, and the medical literature for mention of aneurysm or pseudoaneurysm after MFB. Case details were aggregated, and the rate of aneurysmal deterioration was estimated. Immunohistopathologic examination of institutional explanted specimens was performed to elucidate a cause.

RESULTS

We found 42 cases of aneurysmal deterioration with adequate detail for analysis; all occurred with full root replacement and valve sizes ranging from 23 to 29 mm. The rate of aneurysmal deterioration considering all data sources was 1.1% (9 of 851; 95% confidence interval, 0.5% to 2.0%) vs 4.7% (4 of 86; 95% confidence interval, 1.3% to 11.5%) at our institution, where yearly surveillance imaging is performed. Rate of aneurysmal deterioration appeared constant until 5 years after the operation; however, events are reported out to 10 years. Consistent with previous reports, histopathology demonstrated an immune cell infiltrate in areas of MFB wall breakdown.

CONCLUSIONS

Aneurysmal deterioration is an increasingly described complication of MFB implantation as a full root, with an incidence as high as 4.7%. Given the observed immune reaction and lack of occurrence in smaller (19-mm and 21-mm) valve sizes, inadequate pressure fixation of larger valves is a potential etiology. Patients with MFB require annual surveillance imaging, and consideration of this complication should factor into preoperative decision making because treatment mandates redo root replacement, which may not be feasible in high-risk patients.

Case Report and Review of Literature: Late Retrograde Type A Aortic Dissection With Rupture after Repair of Type B Aortic Dissection with a GORE TAG Endovascular Prosthesis

Acute aortic dissection is the most common catastrophic condition of the aorta. Treatment options include open surgery and thoracic endovascular aortic reconstruction (TEVAR). We present a late Type A dissection as a complication of the management of descending aortic dissections with TEVAR and a review of the literature. TEVAR of the thoracic aorta is a viable treatment option for the management of complicated descending thoracic aortic dissections. Careful patient selection is necessary as medical therapy successfully treats the majority of uncomplicated Type B dissections. TEVAR should be reserved for patients with complicated Type B dissections or those who fail nonoperative management. Close postoperative monitoring is necessary when TEVAR is performed and should be accompanied by lifelong surveillance. A high level of suspicion is important to identify retrograde Type A dissections in these patients given its rarity and the ambiguity of its clinical presentation.

The Bentall procedure with a biological valved conduit: substitute options and techniques

As originally described by Bentall and De Bono, aortic root replacement with reimplantation of the coronary arteries using a composite valved conduit represents the gold standard intervention in patients with aneurysmal disease or dissection involving the aortic root. Over the last decade, the number of Bentall procedures performed using biological valved conduit has dramatically expanded mainly due to the increased incidence of aortic disease in the aging population. Here, we sought to describe the commercially available biological composite grafts and the techniques that, to the best of our knowledge, are most frequently used in this setting.

Long-term results after aortic root replacement using self-assembled valve composite grafts in patients with small aortic annulus

OBJECTIVES

The study was aimed to evaluate operative and long-term results after complete root replacement using self-assembled valve composite grafts in patients with a small aortic annulus.

METHODS

Among 547 consecutive patients who received the Bentall procedure between 2000 and 2012, a total of 29 patients (61 ± 10; range 42-79 years) had an annulus of ≤20 mm (mean 19.0 ± 0.9). Patients with a native aortic valve (22) suffered from stenosis, insufficiency or mixed defect in 10, 10 and 2 cases, respectively. Among the remaining 7 patients with an artificial aortic valve, there were 3 symptomatic prosthesis-patient mismatches, 3 valve prosthesis deteriorations (1 structural and 2 none-structural) and 1 paravalvular leak. Indication for aortic root replacement was true or false aneurysm, porcelain aorta and intraoperative aortic wall injury in 17, 6 and 6 patients, respectively.

RESULTS

The composite graft for complete aortic root replacement was assembled using a mechanical (26) or biological (3) valve prosthesis placed inside a vascular graft with a median size of 24 (range 22-26) mm. The margin of the tube beneath the valve was anastomosed to the aortic annulus, and coronary ostia were implanted in the usual manner. The mean transvalvular gradient at discharge was 10.8 ± 3.9 mmHg and remained virtually unchanged at the follow-up completed for all patients. Early mortality was 0. During the mean follow-up of 95.8 ± 43.7 months, 2 patients died (54 and 146 months after surgery) due to pulmonary embolism and myocardial infarction, respectively.

CONCLUSIONS

In patients with a small aortic annulus who need complete aortic root replacement, an oversizing of the valve can be easily achieved using modified, self-assembled composite grafts. Offering excellent haemodynamic characteristics, these grafts lead to prevention of prosthesis-patient mismatch and result in very good and durable functional and clinical results.