Sebastian Holinski

Ten Years of Clinical Results With a Tissue-Engineered Pulmonary Valve

BACKGROUND This study was performed to collect prospective safety and effectiveness data from a tissue-engineered heart valve implanted for reconstruction of the right ventricular outflow tract during the Ross operation. METHODS From May 2000 until June 2002, 11 consecutive patients, mean age 39.6 ± 10.3 years, received a tissue-engineered heart valve (additive and logistic European System for Cardiac Operative Risk Evaluation, respectively, 3.3 ± 1.3 and 2.8% ± 1.4%). Two to four weeks prior to the Ross operation a piece of forearm vein or saphenous vein was harvested to isolate, characterize, and expand endothelial cells. A cryopreserved pulmonary allograft was decellularized, coated, and seeded with autologous vascular endothelial cells, using a specially developed bioreactor. Cell seeding density was 1.1 × 10(5) ± 0.5 × 10(5) cells/cm(2) with a viability of 93.2% ± 2.1%. RESULTS All patients survived surgery. Postoperatively no fever of unknown origin was evident. Currently all patients are in New York Heart Association class I. Evaluation of the tissue-engineered heart valve by transthoracic echocardiography showed a mean pressure gradient of 5.4 ± 2.0 mm Hg at 10 years. Multislice computed tomography showed no calcification up to 10 years. CONCLUSIONS Tissue-engineered heart valves showed excellent hemodynamic performance and may prevent degeneration during long-term follow-up.

Noninvasive monitoring of cardiac function in a chronic ischemic heart failure model in the rat: Assessment with tissue Doppler and non-Doppler 2D strain echocardiography

ObjectivesFeasibility of noninvasive monitoring of cardiac function after surgically induced ischemic cardiomyopathy with tissue Doppler and non-Doppler 2D strain echocardiography in rats.BackgroundThe optimal method for quantitative assessment of global and regional ventricular function in rats with chronic heart failure for research purposes remains unclear.Methods20 rats underwent suture ligation of the left anterior descending coronary artery via a left thoracotomy to induce ischemic cardiomyopathy. Echocardiographic examination with estimation of left ventricular wall thickness, diameters, fractional shortening, ejection fraction, wall velocities as well as radial strain were performed before and 4 weeks after surgery.ResultsMean LVEF decreased from 70 ± 6% to 40 ± 8% (p < 0.0001) one month after the operation. LVEDD increased from 7 ± 1 mm to 9 ± 1 mm (p < 0.0001), systolic anterior velocity decreased from 0.79 ± 0.25 cm/s to 0.18 ± 0.19 cm/s (p < 0.0001). Radial 2D strain was significantly reduced after myocardial infarction of the septal (18.2 ± 6.6% vs 7.0 ± 5.9%, p < 0.001), anteroseptal (17.3 ± 5.2% vs 4.6 ± 3.0%, p < 0.0001), anterior (18.9 ± 5.9% vs 5.6 ± 2.5%, p < 0.0001), lateral (21.4 ± 4.9% vs 8.1 ± 3.5%, p < 0.0001) as well as posterior myocardial segments (19.3 ± 5.2% vs 15.4 ± 5.5%, p < 0.01). Inferior segments (19.2 ± 7.9% vs 17.8 ± 7.9%, ns) did not change at all.ConclusionIt is feasible to assess dimensions, global function, and regional contractility with echocardiography in rats suffering from chronic heart failure after myocardial infarction. Particularly regional function can be exactly evaluated if tissue Doppler and 2D strain is used.

Redo procedures for degenerated stentless aortic xenografts and the role of valve-in-valve transcatheter techniques†

Objectives This study evaluates reinterventions for degenerated stentless aortic xenografts. Methods Between 2010 and 2015, 52 consecutive patients (age 72.3 ± 9.7 years, EuroSCORE II 11.1 ± 8.9%) underwent reintervention for failed stentless aortic valves (60% porcine, 40% pericardial, 87% sub-coronary, 81% isolated/combined regurgitation). Results Based on age, EuroSCORE II, the presence of pulmonary hypertension, renal failure, a patent internal mammary artery graft and required concomitant procedures, the heart team assigned 25 patients to reoperation and 27 to valve-in-valve transcatheter aortic valve implantation (ViV-TAVI). Valve implantation was successful in all surgical (24% root replacement) and in 24 transcatheter cases (93% trans-femoral, 56% balloon-expandable). Procedural complications were aortic dissection ( n  = 1) during reoperation and coronary obstruction ( n  = 4), device malpositioning ( n  = 3), deployment of >1 valve ( n  = 2) and vascular access site complications ( n  = 2) during ViV-TAVI. Thirty-day mortality (10%, three ViV-TAVI patients, two surgical patients, P  = 1.0) was associated with preoperative renal failure, >1 concomitant procedure, life-threatening bleeding, coronary obstruction and necessity for prolonged circulatory support. ViV-TAVI was beneficial regarding ventilation time, transfusion requirements and the incidence of sepsis. Overall, functional (94% New York Heart Association Class I/II) and echocardiographic results (indexed effective orifice area 0.95 ± 0.27 cm 2 /m 2 , mean transvalvular gradient 14 ± 6.8 mmHg) were favourable. After ViV-TAVI, aortic regurgitation was mild and moderate in two and three patients. One-year survival was 82.3 ± 5.4% and similar after surgery (83.1 ± 7.7%) and ViV-TAVI (81.5 ± 7.5%, P  = 0.76). Conclusions Reinterventions for degenerated stentless aortic valves are challenging. Although ViV-TAVI is appropriate in high-risk patients, limitations and potential complications must be considered. Redo surgery has its place in low-risk patients and if concomitant procedures are required.

Predictive Power and Implication of EuroSCORE, EuroSCORE II and STS Score for Isolated Repeated Aortic Valve replacement

OBJECTIVE We evaluated the predictive power of the EuroSCORE, EuroSCORE II and Society of Thoracic Surgeons (STS) score for isolated redo aortic valve replacement. MATERIALS AND METHODS 78 consecutive patients underwent the aforementioned procedure mainly with a stentless valve prosthesis at our institution. Observed mortality was compared to the predicted mortality, Receiver Operating Characteristics (ROC) curves were calculated and the area under the curve (AUC) analyzed. RESULT Observed mortality was 11.5%. EuroSCORE and EuroScore II predicted a mortality of 28.2 ± 21.6% (p <0.001) and 10.2 ± 11.8% (p = 0.75), respectively. AUC of the EuroSCORE was 0.74 (95% CI: 0.62-0.83), p = 0.009 and of the EuroSCORE II 0.86 (95% CI: 0.76-0.93), p <0.0001. Optimal Youden index of the EuroSCORE II was 0.59 referring to a predicted mortality of 9.9% (sensitivity: 77.8% and specificity: 81.2%). Predicted mortality of STS score was 17.8 ± 10.6% (p = 0.08) and AUC was 0.64 (95% CI: 0.53-0.75), p = 0.06. CONCLUSION EuroSCORE II calculation was not only superior to EuroSCORE and STS score but led to a very realistic mortality prediction for this special procedure at our institution. A EuroSCORE II greater 10 should encourage to consider an alternative treatment.

Suitability of the Rat Subdermal Model for Tissue Engineering of Heart Valves

Background Tissue engineering (TE) is a promising approach to overcome problems associated with biological heart valve prosthesis. Currently several animal models are used to advance this method. The rat subdermal model is uncomplicated and widely used, but its suitability for TE has not yet been shown. Material/Methods Using the rat subdermal model we implanted two decellularized porcine aortic wall specimens (of which one was endothelialized) and one native porcine aortic wall specimen in 30 Lewis rats, respectively. Endothelial cells (EC) were harvested from the rat jugular veins. After explantation Hematoxylin/Eosin-staining, CD-68-positive cell staining, fibroblast-staining and Von-Willebrand factor staining were performed. Results All animals survived without complications. Endothelialization was confirmed to be effective by Giemsa staining. Histological evaluation of specimens in Hematoxylin/Eosin staining showed significant decrease (p<0.05) of inflammatory reaction (confirmed by CD-68-positive cell staining) after decellularization. All specimens showed strongest inflammatory reactions at areas of destroyed extracellular matrix. Fibroblasts could be detected in all specimens, with strongest infiltration in decellularized specimens (p<0.05). Surrounding endothelialized specimens had no monolayer of endothelial cells, but a higher density of blood vessels occurred (p<0.05). Conclusions The subdermal model provides excellent contact of host tissue with implanted specimens leading to rapid cellular infiltration; therefore, we could ascertain reduced inflammatory response to decellularized tissue. Due to the subdermal position, an absence of blood stream and mechanical stress occurs, which influences cellular repopulation; therefore, endothelialization did not lead to an EC monolayer, but rather to increased vascularization. Thus, the model appears ideal for investigating basic biological compatibility, but further questions must be researched using other models.

Covered Perforated Aortocoronary Saphenous Vein Graft Aneurysm

Abstract  We report a case of a 75‐year‐old man suffering from a covered perforated aneurysm of a saphenous bypass graft to the right coronary artery (RCA) constructed 22 years ago. Additional complete revascularization had been performed in 2001. A thoracic computed tomography scan for evaluation of fever of unknown origin had revealed a huge hematoma in front of the right heart. Coronary angiography showed open bypasses but an irregular‐shaped aneurysm of the venous graft to the RCA right before the distal anastomosis. Occurrence of a new right‐sided pleural effusion led to the emergent operation since rupture of the aneurysm and drainage into the pleura was likely. A massive precordial hematoma was found and the existence of the perforated aneurysm could be confirmed. After institution of cardiopulmonary bypass the graft was resected. Since the patient had a functioning bypass to the RIVP, there was no need for additional revascularization. The patient underwent an uneventful postoperative course.

From baby to man with a piggyback heart: long-term success of heterotopic heart transplantation

We present a case of a young man, who underwent heterotopic heart transplantation 20 years ago, when he was 6 months old. The baby suffered from severe intractable cardiomyopathy. In this desperate situation only a miniature, compromised donor heart became available. Today, the young man is fully active under minimal immunosuppression. His surgical course is reviewed and described.

Tissue engineering with a decellularized valve matrix

Tissue engineering requires scaffolds, which are of biologic or synthetic origin. Synthetic scaffolds have the advantage of sterility and no occurrence of immunologic barriers; however, the degradation process is unpredictable and thus the hemodynamic behavior is also unpredictable. Biologic scaffolds have the advantage that suitable animals, e.g., pigs, are abundant, the macroarchitecture is close to human anatomy which eases surgical handling and implantation, and their microarchitecture is adapted to load conditions. Disadvantages are the threats of rejection and infection, which also implies transmission of specific viruses. These drawbacks can be overcome only by complete decellularization.