Ludwig C. Mueller

Multislice Computed Tomography in Infective Endocarditis Comparison With Transesophageal Echocardiography and Intraoperative Findings

OBJECTIVES The aim of this study was to assess the value of multislice computed tomography (CT) for the assessment of valvular abnormalities in patients with infective endocarditis (IE) in comparison with transesophageal echocardiography (TEE) and intraoperative findings. BACKGROUND Multislice CT has recently shown promising data regarding valvular imaging in a 4-dimensional fashion. METHODS Thirty-seven consecutive patients with clinically suspected IE were examined with TEE and 64-slice CT or dual-source CT. Twenty-nine patients had definite IE and underwent surgery. RESULTS The diagnostic performance of CT for the detection of evident valvular abnormalities for IE compared with TEE was: sensitivity 97%, specificity 88%, positive predictive value (PPV) 97%, and negative predictive value (NPV) 88% on a per-patient basis (n = 37; excellent intermodality agreement kappa = 0.84). CT correctly identified 26 of 27 (96%) patients with valvular vegetations and 9 of 9 (100%) patients with abscesses/pseudoaneurysms compared with the intraoperative specimen. On a per-valve-based analysis, diagnostic accuracy for the detection of vegetations and abscesses/pseudoaneurysms compared with surgery was: sensitivity 96%, specificity 97%, PPV 96%, NPV 97%, and sensitivity 100%, specificity 100%, PPV 100%, NPV 100%, respectively, without significant differences as compared with TEE. Vegetation size measurements by CT correlated (r = 0.95; p <0.001) with TEE (mean 7.6 +/- 5.6 mm). The mobility of vegetations was accurately diagnosed in 21 of 22 (96%) patients with CT, but all of 4 leaflet perforations (<or=2 mm) were missed. CT provided more accurate anatomic information regarding perivalvular extent of abscess/pseudoaneurysms than TEE. CONCLUSIONS Multislice CT shows good results in detecting valvular abnormalities in IE and could be applied in pre-operative planning and exclusion of coronary artery disease before surgery.

Zygomycosis and other rare filamentous fungal infections in solid organ transplant recipients

Fungi cause severe infections in solid organ transplant (SOT) recipients. Recently, a shift towards non‐Aspergillus filamentous fungal infections (nAFFI) was noticed. In a series of 2878 SOTs (kidney, pancreas, islets, liver, heart, lung, and bowel) performed between January 1995 and December 2006 at the Innsbruck medical university, eleven cases of nAFFI were diagnosed. The encountered species included Zygomyzetes (n = 8), and Alternaria alternate, Pseudallescheria boydii, Trichoderma spp. (one each); there were three liver and three heart, one intestinal, pancreas, lung, bilateral forearm and renal recipient each. Five patients died from nAFFI (zygomycosis: 4, Pseudallerichia boydii: 1); four were diagnosed postmortem. In five cases infection was surgically treated in combination with antifungals. Risk factors for nAFFI were renal failure (73%) and intensified immunosuppression (73%); two cases were associated with post‐transplant lymphoproliferative disorder, one with graft versus host disease. An increase in the incidence of nAFFI was observed parallel to introduction of caspofungin and voriconazole (three cases until 12/2003, seven cases thereafter). NAFFI are increasingly found in SOT recipients. If diagnosed in time, the outcome seems acceptable. Intensified immunosuppression and exposure to antifungals not active against zygomycetes may be risk factors. Surgical therapy may play an important role in these infections.

Shunt or Snare: Coronary Endothelial Damage due to Hemostatic Devices for Beating Heart Coronary Surgery

BACKGROUND Occlusion of coronary arteries during off-pump coronary bypass operations bears the potential for endothelial injury. The aim of this study was to elucidate the effects of hemostatic devices on the beating heart in human coronaries by means of scanning electron microscopy. METHODS The coronary arteries of 9 patients with dilated cardiomyopathy and 13 with ischemic heart disease undergoing heart transplantation were handled with intracoronary shunts as well as external snaring techniques on a beating heart, after cannulation but before starting cardiopulmonary bypass. Adjacent noninstrumented coronary artery segments served as controls. Integrity of endothelial lining was observed with scanning electron microscopy. RESULTS Nearly all coronary artery segments manipulated with a shunt exhibited a severe injury with extensive endothelial denudation. Endothelial injury was significantly higher after manipulation with intracoronary shunts compared with external occlusion devices (p < 0.001) or control specimens (p < 0.001). Plaque rupture was apparent in 3 samples. CONCLUSIONS Manipulation of human coronary arteries during off-pump operations leads to endothelial denudation and plaque rupture. From this investigation we conclude that insertion of intracoronary shunts during beating heart operations leads to severe endothelial denudation in human coronary arteries. We therefore recommend using shunts selectively in cases where critical ischemia or technical difficulties due to anatomic conditions are expected during anastomosis. The clinical significance of these structural damages has to be further investigated with clinical trials.

Severe endocarditis in transplant recipients – an epidemiologic study*

Infective endocarditis (IE) is reported with an incidence of 6/100 000 inhabitants in the general population. Even though immunosuppression predisposes to systemic infection, reports regarding IE after solid organ transplantation (SOT) are sparse. From 1989 to 2004, 2556 patients underwent SOT at the University Hospital Innsbruck. During this period, 27 transplant recipients were diagnosed IE. Nine patients (33.3%) were diagnosed at autopsy, eight patients (29.6%) were cured by antibiotic treatment and 10 patients (37.1%) underwent surgery. Overall mortality was 44.4% (12 patients). Staphylococcus was the predominant microorganism in 16 cases (59.3%), fungal infection was present in four patients (14.8%). Incidence of IE was 1% (95% CI: 0.67–1.49), indicating a 171‐fold risk compared with the overall population. IE after SOT constitutes a significant problem and is associated with an excessive high mortality. Alertness to this condition is indicated, as we might diagnose more cases of IE in the future.

Atrioesophageal Fistula After Percutaneous Transcatheter Ablation of Atrial Fibrillation

A 45-year-old white man presented to the emergency department because of fever and fluctuating neurological symptoms including weakness and sensory loss of the right limbs. Six weeks before admittance, the patient had undergone percutaneous transcatheter ablation of drug-refractory atrial fibrillation. Laboratory examination showed markedly elevated white cell count and inflammatory markers, as well as moderately increased cardiac troponin T; however, no chest pain or gastrointestinal symptoms were reported, and the ECG was normal. Computed tomography (CT) scan of the chest revealed a fistula between the …

Simple adaptations of surgical technique to critically reduce the risk of postoperative sternal complications in patients receiving bilateral internal thoracic arteries

OBJECTIVES Limited blood supply to the thoracic chest wall is a known risk factor for sternal wound complications after CABG. Therefore, bilateral internal thoracic arteries are still rarely utilized despite their proven superior graft patency. The aim of our study was to analyse whether modification of the surgical technique is able to limit the risk of sternal wound complications in patients receiving bilateral internal thoracic artery grafting. METHODS All 418 non-emergent CABG patients receiving bilateral internal thoracic artery CABG procedures (BITA) from January 2001 to January 2012 were analysed for sternal wound complications. Surgical technique together with known risk factors and relevant comorbidity were analysed for their effect on the occurrence of sternal wound complications by means of multivariate logistic regression analysis. RESULTS Sternal wound complications occurred in 25 patients (5.9%), with a sternal dehiscence rate of 2.4% (10 patients). In multivariate analysis, diabetes (odds ratio [OR]: 4.8, 95% CI: 1.9-11.7, P=0.001), but not obesity (OR: 1.6, 95% CI: 0.7-4.2, P=0.28) or chronic obstructive pulmonary disease (OR: 2.2, 95% CI: 0.87-5.6, P=0.1) was a relevant comorbid condition for sternal complications. Skeletonization of ITA grafts (OR: 0.17, 95% CI: 0.06-0.5, P=0.001) and the augmented use of sternal wires (OR: 0.24, 95% CI: 0.06-0.95, P=0.04) were highly effective in preventing sternal complications. The use of platelet-enriched-fibrin glue (PRF) sealant, however, was associated with more superficial sternal infections (OR: 3.7, 95% CI: 1.3-10.5, P=0.02). CONCLUSIONS Adjusted for common risk factors, skeletonization of BITA grafts together with augmented sternal wires is effective in preventing sternal complications. The use of PRF sealant, however, increased the risk for superficial wound complications.

Single time point measurement by C2 or C3 is highly predictive in cyclosporine area under the curve estimation immediately after lung transplantation

Abstract:  Background:  The two h post‐dose cyclosporine (CsA) concentration has been advocated as the optimal time point measurement for CsA area under the curve (AUC) estimation after solid organ transplantation. The aim of the study was to investigate whether intensified CsA monitoring is necessary, or if a single time point measurement is accurate to estimate the AUC in the very early period following lung transplantation (LuTX).

Prolonged But Successful Weaning from Left Ventricular Assist Device After Cardiac Decompensation due to Late-Recognized Coarctation of the Aorta in a Toddler

A 2-year-old boy was presented with late-recognized coarctation of the aorta and pulmonary hypertension due to left ventricular failure. The coarctation was corrected at the day of admission with a good postoperative result. However, weaning from the respirator failed despite multiple drug support due to left ventricular failure. Consequently, a left ventricular assist device (LVAD) was implanted 22 days later. The further course was complicated by systemic hypertension and ongoing pulmonary hypertension requiring extensive antihypertensive therapy. The first attempt to wean from LVAD failed and the left ventricle was left completely unloaded for additional 4 weeks. The second weaning attempt, using a very smooth weaning protocol, led to a recovered left ventricle and facilitated the removal of the assist device after a total of 120 days. The patient was discharged with normal cardiac function, but he still requires antihypertensive therapy. We believe that the slow reduction of the LVAD support was the key measure that leads to the successful weaning of the patient, thereby avoiding heart transplantation.

Cardiac transplantation complicated by acute thrombotic occlusion of the right coronary artery.

We report the case of a 63-year-old male patient undergoing cardiac transplantation due to fourth time aortic valve endocarditis. The postoperative course was complicated by thrombotic occlusion of the right coronary artery (RCA) causing acute right ventricular myocardial infarction, which required extracorporeal membrane oxygenation. The RCA could be reopened by catheter-based intervention and the patient stabilized. In order to avoid further immobilization, a right ventricular assist device was implanted and an aortocoronary bypass to the RCA was performed. After that, the patient stabilized progressively, could be weaned from the assist device, and was discharged home 6 weeks after transplantation. On coronary angiography, which is routinely performed 4 to 6 weeks after transplantation, a fistula from the RCA to the right ventricle was detected which was treated conservatively. Five months after transplantation, the patient is in good clinical condition without signs of recurrent endocarditis. This case shows that intense interdisciplinary cooperation of cardiac specialists allows the successful management of very complex patients in serious clinical conditions.

Mitral Valve Surgery via Partial Upper Sternotomy: Closing the Gap between Conventional Sternotomy and Right Lateral Minithoracotomy

BACKGROUND  Minithoracotomy (MT) has gained broad acceptance for mitral valve surgery (MVS) in the last decade. In the presence of defined limitations of MT, however, full sternotomy (FS) is still widely preferred. We assume that the less investigated partial upper sternotomy (PS) will permit the gap between MT and FS in MVS to be closed. The purpose of this study is to investigate a valid less invasive alternative to MT for isolated MVS or multivalve surgery. METHODS  This retrospective analysis includes data on 1,639 patients, who underwent either isolated or combined primary MVS at our department from May 2011 to August 2017. Out of these, 663 patients were operated via MT access. One-hundred three patients had been judged as not suitable for MT but feasible for PS approach in which 53.4% (n = 55) had isolated MVS and 46.6% patients (n = 48) underwent multivalve surgery. Concomitant myocardial revascularization was performed in 2.9% of the study patients (n = 3). RESULTS  Operative, 90-day, and 1-year mortality in the PS-cohort was 0, 1.0% (n = 1), and 3.3% (n = 3), respectively. During a median follow-up time of 1,115 days (interquartile range 398-1806), all-cause mortality was 5.8% (n = 6). Operative times for cardiopulmonary-bypass and cross-clamping were 167 minutes (140-198) and 107 minutes (93-132), respectively. Median length of stay at the intensive care unit and hospital was 1 (1-2) and 7 days (7-10), respectively. CONCLUSION  The presented results demonstrate that there is a cohort of patients, who are not candidates for MT in MVS but may be operated successfully by an alternative less invasive approach.