Roland Hetzer

Surgical management of acute aortic root endocarditis with viable homograft: 13-year experience.

OBJECTIVE Cryopreserved homograft valves have been used for acute infective aortic root endocarditis with great success but it is compounded by its availability in all sizes. The long-term clinical results of geometric mismatched homografts are not well defined and addressed. METHODS Over a 15-year period (April 1986-June 2001), 816 patients presented with active infective endocarditis. One hundred and eighty-two of the patients aged between 9 and 78 years (mean: 51.0 +/- 1.13 years) consisting of 142 males and 40 females received homograft aortic valves. One hundred and ten patients were in NYHA functional class III and 72 in class IV and in cardiogenic shock. Of the patients, 2.7% suffered from septic embolism. One hundred and twenty-four (68.1%) patients presented with periannular abscesses and 58 (31.9%) with no abscess while 107 native valve (NVE) and 75 prosthetic valve (PVE) endocarditis were diagnosed preoperatively by transesophageal echocardiography (TEE) and confirmed intraoperatively. Freehand subcoronary implantation (FSCI) was used in 106 patients and root replacement in 76 patients. RESULTS The operative death was 8.5% and for patients in NYHA functional class IV and in cardiogenic shock was 14.5%. Late mortality rate was 7.9%. Patient survival after discharge from hospital at 1 year was 97% and at 10 years was 91%, respectively. Thirty-one (22.1%) patients underwent reoperation after 1.7 years (mean) with two deaths (6.4%). Early (< or = 60 days) and late reinfection rate was 2.7 and 3.6%, respectively. Freedom from reoperation for matched and undersized homografts at 10-13 years was 85 and 55%, respectively. The univariate model identified undersized homograft (P=0.002), FSCI (P=0.09) and reinfection (P=0.0001) as independent risk factors for developing early and late valve dysfunction resulting in reoperation and homograft explant. CONCLUSION Early aggressive valve replacement with homograft for active infective aortic root endocarditis with periannular abscesses is more successful than delayed last resort surgery. Homografts exhibit excellent clinical performance and durability with a low rate of reinfection, if properly inserted. Undersized homograft is an incremental risk factor for early and late reoperation.

The impact of gelatin-resorcinol glue on aortic tissue: A histomorphologic evaluation

PURPOSE Although gelatin-resorcinol-formaldehyde glue has been used to treat acute aortic dissections for some time, concerns about formaldehydes mutagenicity and carcinogenicity made it imperative to develop a new glue compound. Gelatin-dialdehyde glue was produced by omitting the formaldehyde component and replacing it with two less toxic aldehydes, glutaraldehyde and glyoxal. This study evaluated the histomorphologic effects of the new glue through in vivo use on the aortic tissue of domestic pigs. METHODS Each animals infrarenal aorta was glued around an implanted prosthesis. Histomorphologic evaluation was performed after operation after 1 and 4 weeks. RESULTS The results demonstrated that the clinically observed tanning effect can be attributed primarily to the disintegration of the fiber texture, specifically collagenous, as well as smooth muscle fibers, and to the reciprocal alterations of the proteoglycan interstitial substance in the aortic wall. Macroscopic, microscopic, and electron microscopic analysis of the gluing process revealed an adequate healing process without any morphologically significant difference between formaldehyde and formaldehyde-free gelatin-resorcinol glue. CONCLUSIONS Gelatin-dialdehyde glue is able to produce the same effects in the area of the aortic wall as the substantially more toxic gelatin-resorcinol-formaldehyde glue and thus could be recommended for clinical trials for treating acute aortic dissections thus far yielding excellent initial results.

Electron-Beam Computed Tomography in the Assessment of Coronary Artery Disease After Heart Transplantation

BACKGROUND Our aim was to compare the electron-beam CT (EBCT) features of coronary arteries in heart transplant recipients with those of biplane coronary angiography and intracoronary ultrasound (ICUS). METHODS AND RESULTS We examined 112 heart transplant recipients (25 female; age, 17 to 69 years; median, 52 years) 1 to 153 months (median, 46 months) after surgery by EBCT to detect coronary artery calcifications. Calcifications were quantified by the Agatston scoring system. EBCT scores were compared with coronary angiography in all patients and ICUS of the left anterior descending coronary artery (LAD) in 100 patients. Coronary artery calcifications were found in 84 patients (75%). Angiographically, 16 patients displayed >50% coronary artery stenoses, all of whom had some degree of coronary artery calcification and only 1 of whom had a score of <55 (P<0.0001). With this threshold, EBCT had a sensitivity of 94%, a specificity of 79%, a positive predictive value of 43%, and a negative predictive value of 99% for detecting stenosis. ICUS confirmed the presence of calcified plaques in all patients with an LAD score >9. EBCT total calcium score was associated with the degree of intimal proliferation in that patients without ICUS features of allograft vasculopathy had a median score of 0 (25th percentile, 0; 75th percentile, 0), whereas patients with Stanford class IV vasculopathy had a median score of 41 (9 to 98, P<0.0001). CONCLUSIONS EBCT is a promising noninvasive test for the detection of coronary heart disease in cardiac transplant recipients.

Right Ventricular Function in Patients Treated With Inhaled Nitric Oxide After Cardiac Surgery for Congenital Heart Disease in Newborns and Children

Measurement of right ventricular (RV) function is essential for complete assessment of the effects of inhaled nitric oxide in the postoperative cardiac patient; nitric oxide therapy can result in a decrease in pulmonary vascular resistance and improved echocardiographic RV ejection fraction without necessarily inducing a significant change in pulmonary artery pressure.

Noninvasive diagnosis of cardiac rejection through echocardiographic tissue characterization

Ultrasonic tissue characterization is based on the assumption that microscopic tissue structures are identifiable by their acoustic properties. Our study group consisted of 23 cardiac recipients. Two-dimensional images were obtained within 2 hours of endomyocardial biopsy. The end-diastolic echo frames were digitized into the matrix of an image-processing system. A region of interest was placed into the anteroseptal segment of the left ventricle. The texture within the region of interest was analyzed using four major groups of texture analysis (first-order histogram, co-occurrence matrix, run-length statistic, and power spectrum). A total of 408 echocardiographic examinations were compared with histologic findings. The 117 initially calculated texture parameters were reduced incrementally using a series of discriminant analyses. A set of three texture parameters (inverse difference moment undirected, run-length nonuniformity vertical, and sector sum) was able to describe changed echocardiographic texture when rejection occurred. Using these three parameters, echocardiographic sensitivity was 89.0% and specificity was 83.6% for moderate rejection. We conclude that cardiac rejection is associated with echocardiographic texture alterations and that serial echocardiographic texture analysis can reliably identify rejection.

Pulmonary Interstitial and Vascular Abnormalities Following Cardiac Transplantation

Impairment of pulmonary diffusion (KCO) is frequently seen in patients following orthotopic heart transplantation (HTX). To assess potential histomorphological pulmonary causes of KCO abnormalities, we evaluated tissue samples from 73 patients who succumbed after HTX in the presence of KCO abnormalities, excluding those with infectious or primary pulmonary causes of death. In 97% of subjects, we observed considerable histomorphological changes in interstitial or vascular tissue or both. In 32% of samples, interstitial changes (eg, cell proliferation or fibrosis) were accompanied by vascular abnormalities, whereas more than two-thirds of the patients showed alterations in one of the two conditions. Hemosiderin-laden macrophages were observed in 48% of subjects. The mean alveolar-capillary wall thickness was significantly increased to 9.9 +/- 4.2 mum. The time of survival after HTX was not correlated with the incidence of pathological findings. The described vascular and interstitial pulmonary changes as well as the increased membrane thickness may cause the persistent impairment of KCO after HTX.

Nachweis viraler Genomstrukturen im Myokardgewebe von Herzklappenspendern

Zusammenfassung Virale Infekte sind häufig als Ursache inflammatorischer Herzerkrankungen beschrieben worden. Diese können im Rahmen einer chronisch persistierenden Verlaufsform zu einer andauernden Herzinsuffizienz führen und eine Herztransplantation (HTx) erforderlich machen. Sie sind auch als Hauptursache postoperativer Morbidität und Mortalität bei Herztransplantationspatienten (HTx-Patienten) bekannt. Bisher gibt es keine gesicherten Daten über das Vorkommen kardiotroper Viren in Homografts und das gesundheitliche Risiko für die Empfänger von Herzklappen.    In dieser Studie wurden, zwischen April und Dezember 2001, Myokardproben von 50 Spenderherzen – 34 Explantate von HTx-Patienten (Dominoherzen) mit einem Durchschnittsalter von 47 Jahren und 16 Explantate von Multiorganspendern (MOS), die für eine Organspende ungeeignet waren, mit einem Durchschnittsalter von 45 Jahren – mit der Methode der Polymerasekettenreaktion (PCR) auf das Vorhandensein von viralen Genomsequenzen von Enteroviren, Zytomegalieviren, Adenoviren und Influenzaviren untersucht. Die PCR-Befunde wurden mit der Serologie und den histopathologischen Befunden verglichen, um den Nutzen dieser Methoden für eine Herzklappenbank besser bewerten zu können. In 16 Spenderherzen (32%) konnten virale Genomsequenzen nachgewiesen werden, die auf eine virale Infektion im Myokard hinweisen. In 10 Herzen (20%) wurden Sequenzen von Enteroviren und in jeweils sechs Herzen (12%) von Zytomegalie- und Adenoviren nachgewiesen. In sechs Herzen wurden Doppelinfektionen mit zwei Virustypen gefunden. Alle untersuchten Herzen waren negativ auf Influenzaviren (Typ A und B). In 12 von 16 (75%) „infizierten” Spenderherzen wurden morphologische Veränderungen der Myokardarchitektur beobachtet. Unklar bleibt jedoch, ob diese auf die virale Infektionen zurück zu führen sind. Nur bei einem der 16 „infizierten” Spenderherzen wurde die Verwendung von Homografts für humane Zwecke, auf Grund einer histologisch nachgewiesenen floriden Myokarditis, abgelehnt. In diesem Herz wurde mittels PCR eine Enterovirus-Infektion nachgewiesen. Weitere Untersuchungen sind notwendig, um zu beurteilen, ob Herzen, die einen auf Viren positiven PCR-Befund haben, ein besonderes Risiko für die Empfänger von Herzklappen darstellen.    Die PCR ist eine schnelle und sensitive Methode, mit der Virusgenome im Herzgewebe nachgewiesen werden können. Die Implementierung der PCR-Diagnostik zum Nachweis viraler Erreger könnte daher zu einer deutlichen Verbesserung des Qualitätsmanagementsystems (QMS) einer Herzklappenbank führen. Die geforderte Qualitätskontrolle von Organen, Geweben und Zellen soll ein hohes Maß an Sicherheit nach dem neusten Stand der Wissenschaft gewährleisten. Die PCR ist ein nützliches Werkzeug, mit dem wichtige Fragen im Zusammenhang mit der Übertragung von viralen Infekten bei Herz- und Herzklappentransplantationen, akuten Infektionen, Reinfektionen und Komplikationen bezüglich späterer oder chronischer Organabstoßung beantwortet werden können.Summary Viral infections are an important cause of inflammatory cardiac diseases, which often demand heart transplantations (HTx) due to chronic cardiac insufficiency. They are also a major cause of postoperative morbidity and mortality in cardiac transplant recipients. Little is known about the presence of cardiotropic viruses in homografts and the risk of infection in recipients.    In our study, between April and December 2001, we analyzed myocardial samples from 50 hearts of heart-beating donors – 34 explants from cardiac transplant recipients (domino hearts), mean age 47 years and 16 explants from multiorgan donors (MOS), mean age 45 years – for the presence of viral genomes of enteroviruses, cytomegaloviruses, adenoviruses and influenza viruses by the polymerase chain reaction (PCR). The obtained PCR results were compared with the data from the histopathological and serological diagnostics to evaluate the use of the diagnostic methods for heart valve banking. In 16 hearts (32%), we found viral genome sequences indicating a viral infection of the myocardium. Enterovirus-specific sequences were found in 10 hearts (20%), cytomegalovirus and adenovirus DNA were amplified from six hearts, each 12%. In six hearts, double infections by two viruses were detected. However, all organs tested so far were negative for influenza virus (type A and B) genomes. In 12 out of 16 (75%) infected donor hearts morphological changes of the myocard structure were observed. Whether these changes are caused by viral infection remains unclear. Only one heart out of 16 was rejected for transplantation because of a florid myocarditis. In this heart an infection with enterovirus was detected by PCR. Viruses pose a potential risk to the recipient of a heart valve allograft. It must be investigated thoroughly if hearts, either virus positive in PCR only, or virus positive in PCR and suspicious in histological investigation apart from florid infections will cause infections in recipients.    As demonstrated here, PCR is a rapid and sensitive method to detect viral infection in heart tissues. Therefore, PCR analysis for viral infections may significantly improve the quality management system (QMS) in valve banking. Quality assurance for organs, tissues and cells requires high standards of safety based on the state of the art scientific knowledge. PCR will also be a useful tool to answer important questions regarding viral infections transmitted by heart or homograft transplantation, acute infections, relapse and complications regarding late or chronic rejection.

Postoperative Erfolgs- und Verlaufskontrollen thorakaler Aortenerkrankungen mittels Kernspintomographie

SummaryOperations of the thoracic aorta for aneurysms, dissections, or congenital malformations may lead to early or late complications. Therefore, postoperative control for documentation of the surgical results, for exclusion of early changes and for comparison with later controls is mandatory. To demonstrate that magnetic resonance imaging (MRI), which we already had used with good results for preoperative studies is also able to detect postoperative abnormalities, we examined 30 patients with thoracic aortic disease (20 male, 10 female, mean age 53 ± 13.7 years) with this diagnostic tool. There were 19 arteriosclerotic aneurysms, 10 dissections, and one aortic tumor. With MRI it was possible in all patients to visualize the results of the surgical treatment postoperatively. Early postoperative complications could be excluded, or demonstrated in one case of a retrograde aortic dissection or a hematopericardium. These pathological findings could also be shown by arterial digital subtraction angiography or echocardiography. Using MRI for follow-up of aortic dissections, the development of an aneurysm of the aortic root in a Marfan-patient could be detected. In all these patients, it was possible to differentiate true and false lumen and to detect the origin of major side branches. The diagnostic advantages of MRI, which we compared with other imaging methods, as echocardiography, computed tomography or angiography are that postoperative complications of thoracic aortic aneurysm surgery can be reliably detected and visualized in 3 different planes. Non-invasiveness, the omission of ionizing radiation and no risk of contrast media application underline that magnetical resonance imaging is an ideal method for follow-up after operation of the thoracic aorta.ZusammenfassungZwecks überprüfung, inwieweit die Kernspintomographie, die mit gutem Erfolg bereits in der präoperativen Diagnostik eingesetzt wird, eine sinnvolle Bereicherung des diagnostischen Instrumentariums bei der postoperativen Kontrolle thorakaler Aortenerkrankungen darstellt, haben wir zwischen dem 1. 4. 1986 und 30. 3. 1988 30 Patienten (20 männlich, 10 weiblich, mittleres Alter 53 Jahre ± 13,7 Jahre) nach Operation an der thorakalen Aorta kernspintomographisch untersucht. Es lagen 19 arteriosklerotische Aneurysmen, 10 Dissektionen sowie ein Tumor der , Aorta descendens vor. In allen 30 Patienten gelang es, kernspintomographisch postoperativ die Ergebnisse der chirurgischen Maßnahmen zu dokumentieren. Es konnten im frühen postoperativen Stadium Komplikationen ausgeschlossen bzw., wie in einem Fall eine retrograde Aortendissektion oder einem anderen ein Hämatoperikard nachgewiesen werden. In der postoperativen Verlaufskontrolle aortaler Dissektionen ließ sich eine aneurysmatische Dilatation der dissezierten Aorta distal der implantierten Prothese in allen Fällen darstellen. Wahres und falsches Lumen konnten differenziert werden. In einem Fall ließ sich die Ausbildung eines Aortenbulbusaneurysmas nachweisen. Zusammengefaßt lassen sich postoperative Komplikationen der thorakalen Aortenchirurgie mit der Kernspintomographie zuverlässig nachweisen und bildlich in 3 Ebenen darstellen. Nichtinvasibilität, das Fehlen einer ionisierenden Strahlung und das ausbleibende Risiko einer Kontrastmittelapplikation machten die Kernspintomographie zu einer idealen Methode für Folgeuntersuchungen nach Operation an der thorakalen Aorta.

Langzeit-Follow-up nach direkter intramyokardialer Implantation eines A. thoracica-interna-Pedikels (Vineberg-Operation)

We report on a patient with coronary artery 3-vessel disease who presented 30 years after a unilateral Vineberg operation with a patent graft. The patient successfully underwent coronary artery bypass grafting. The theoretical basis, operative variations and the results of this historical indirect revascularization procedure are briefly discussed. Wir berichten über einen Patienten mit koronarer Dreigefäßerkrankung, bei dem noch 30 Jahre nach Direktimplantation der Arteria thoracica interna in einen operativ geschaffenen intramyokardialen Tunnel (Vineberg-Operation) angiographisch ein Blutfluss über diesen Pedikel nachweisbar war, und der nun erfolgreich einer aortokoronaren Bypassoperation unterzogen wurde.    Die theoretische Basis, technische Variationen und die klinischen Ergebnisse nach dieser historischen Operationsmethode werden diskutiert.

Mechanische Herzunterstützungssysteme (2010)

Nach Jahrzehnten intensiver interdisziplinarer Forschung und Entwicklung und ersten Studien des Humaneinsatzes haben heute mechanische Pumpsysteme zur Unterstutzung oder zum Ersatz des versagenden Herzens (Ventricular Assist Devices, VAD, bzw. Total Artificial Heart, TAH) ihren festen Platz in der Behandlung des terminalen Herzversagens gefunden.