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Dive into the research topics where Johannes Kroll is active.

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Featured researches published by Johannes Kroll.


Circulation | 2015

Aneurysms of the Pulmonary Artery

Maximilian Kreibich; Matthias Siepe; Johannes Kroll; René Höhn; Jochen Grohmann; Friedhelm Beyersdorf

Pulmonary artery (PA) aneurysms (PAAs) are rare and infrequently diagnosed. Deterling and Clagett1 discovered 8 cases of PAAs in 109 571 consecutive postmortem examinations. PAAs generally occurred in a younger age group than aortic aneurysms with an equal sex incidence.2 Eighty-nine percent of all PAAs were located in the main PA, whereas only 11% were located in the pulmonary branches.3 When affecting the PA branches, PAAs in the left PA were more common than in the right PA.1 An aneurysm is defined as a focal dilatation of a blood vessel involving all 3 layers of the vessel wall. Pseudoaneurysms, on the other hand, do not involve all layers of the arterial wall but possess a higher risk of rupture. In computed tomography, the upper limit for adults of the main PA diameter is 29 mm, and the upper limit of the interlobar PA is 17 mm.4 Therefore, Nguyen et al5 describe a PAA as a focal dilatation of the PA beyond its maximal normal caliber. In contrast, Brown and Plotnick6 define a PAA as a PA with a diameter exceeding 40 mm, distinguishing between an ectasia of the PA and a true PAA. However, both definitions do not relate the PAA threshold to body dimensions or to the diameters of other vessels. In our center, the upper limit of the main PA diameter (29 mm) was defined as a PAA. In case of a PAA in children, the PAA size was compared with the normal values according to the method of Kampmann et al.7 In high-risk patients, the diameter of the PAA was indexed to the body weight according to patients presenting with an aneurysm of the aorta. Various origins of PAA have been described, allowing us to differentiate among congenital causes, …


European Journal of Cardio-Thoracic Surgery | 2016

Geometric ring annuloplasty as an adjunct to aortic valve repair: clinical investigation of the HAART 300 device

Domenico Mazzitelli; Theodor Fischlein; J. Scott Rankin; Yeong-Hoon Choi; Christof Stamm; Steffen Pfeiffer; Jan Pirk; Christian Detter; Johannes Kroll; Friedhelm Beyersdorf; Griffin Cd; Malakh Shrestha; Christian Nöbauer; Philip S. Crooke; Christian Schreiber; Rüdiger Lange

OBJECTIVES This study assessed the safety and efficacy of an internal geometric annuloplasty ring in a regulatory trial of aortic valve reconstruction (ClinicalTrials.gov Identifier: NCT01400841). METHODS Sixty-five patients with predominant moderate-to-severe trileaflet aortic insufficiency (AI) underwent aortic valve repair with an average age of 63 ± 13 years (mean ± SD). All had initial implantation of an internal aortic annuloplasty ring to correct annular dilatation and facilitate leaflet reconstruction. Leaflet plication was performed for prolapse in 80% of patients, and more complex leaflet procedures, usually employing autologous pericardium, were required in 22%. Ascending aortic and/or root aneurysms were replaced in 62%. RESULTS Follow-up was for a maximum of 3 years and a mean of 2 years. No in-hospital operative mortalities, major complications or early or late valve-related events occurred. The annular diameter before repair was 26.5 ± 2.3 mm, and the average ring diameter used was 21.5 ± 1.6 mm. The preoperative AI grade (0-4) was 2.9 ± 0.8 and improved after repair to 0.6 ± 0.7 (P < 0.0001), as did the NYHA class. The mean valve gradient was 8.6 ± 4.3 mmHg, and at 3 years, the Kaplan-Meier survival rate was 95%, with no valve-related mortality. Over the 3 years, aortic valve replacement was required in 7 patients (10.8%) for reasons usually related to surgical technique. Most repair failures occurred early, and results stabilized after 6 months. No structural complications of the rings were observed. CONCLUSIONS Geometric ring annuloplasty was a safe and effective adjunct to aortic valve repair. Initial correction of annular dilatation seemed to facilitate overall reconstruction. Because most early repair failures were technical, increasing experience with geometric ring annuloplasty for aortic valve reconstruction has the potential to standardize and improve outcomes.


Interactive Cardiovascular and Thoracic Surgery | 2014

Shear-stress induced acquired von Willebrand syndrome in children with congenital heart disease

Florian Loeffelbein; Dominika Funk; Lea Nakamura; Barbara Zieger; Jochen Grohmann; Matthias Siepe; Johannes Kroll; Brigitte Stiller

OBJECTIVES To determine the frequency and severity of acquired von Willebrand syndrome (AVWS) in children with stenotic congenital heart disease (CHD) before and after intervention. METHODS In this single-centre prospective observational case-control study, 50 children [median age: 26 (range, 0-175) months, bodyweight: 9.5 (2.2-7.5) kg] underwent catheter interventions or cardiac surgery. A total of 26 children with high stenosis [mean gradient: 80 (range, 52-130) mmHg] represented the stenosis group and 24 without relevant stenosis (<20 mmHg) served as the control group. von Willebrand factor (VWF) was analysed with respect to quantity and function before and after corrective or palliative intervention. RESULTS Demographic data were comparable. The stenosis group had more surgical and the control group more interventional procedures (P = 0.025). Before intervention, 13 patients from the stenosis group (50%) showed a significant reduction in VWF-multimers compared with no patients in the control group (P <0.001). Collagen binding capacity (VWF:CB) was lower in the stenosis group [0.5 (0.2-2.6) U/ml vs 0.8 (0.4-2.1) U/ml, P <0.05), as was the collagen binding capacity to antigen ratio (VWF:CB/Ag) [0.8 (0.4-1.4) U/ml vs 1 (0.4-1.7) U/ml, P <0.001). After intervention, VWF parameters normalized rapidly within the first 24 h after the procedure and showed no group differences. {VWF:CB [1.7 (0.6-3.7) vs 1.7 (0.6-4.2) U/ml, P = n.s.], VWF:CB/Ag [1.1 (0.5-2.9) vs 1.2 (0.7-2.2), P = n.s} Time in the intensive care unit, respirator time, duration of stay and bleeding before and after intervention were not significantly different. CONCLUSIONS AVWS is detected in half of the children with high intra- or extracardiac stenoses and resolves completely after surgical or interventional repair. Even when undergoing surgery on cardiopulmonary bypass, excessive surgical site bleeding was not detected in our study patients.


Pediatric Critical Care Medicine | 2017

Long-Term Follow-Up on Health-Related Quality of Life After Mechanical Circulatory Support in Children.

Thilo Fleck; Georg Dangel; Felix Bächle; Christoph Benk; Jochen Grohmann; Johannes Kroll; Matthias Siepe; René Höhn; Janbernd Kirschner; Friedhelm Beyersdorf; Brigitte Stiller

Objective: The objective of this study was to evaluate health-related quality of life in long-term survivors of mechanical circulatory support after acute cardiopulmonary failure. Design: Prospective follow-up study. Setting: Single-institutional in a center for congenital heart disease and pediatric cardiology. Patients: Fifty patients who underwent 58 mechanical circulatory support therapies in our institution from 2001 to 2012. Median age was 2 (0–213) months, and median supporting time was 5 (1–234) days. Indication groups: 1) extracorporeal life support in low cardiac output: 30 cases (52%); 2) extracorporeal cardiopulmonary resuscitation: 13 cases (22%); 3) extracorporeal membrane oxygenation in acute respiratory distress syndrome: four cases (7%); and 4) ventricular assist devices: 11 cases (19%). Interventions: Health-related quality of life was measured using standardized questionnaires according to the age group and completed by either parent proxies in children under 7 years old or the survivors themselves. Measurements and Main Results: Fifty percentage of the patients were discharged home, and 22 long-term survivors (44%) were studied prospectively for health-related quality of life. Median follow-up period was 4.5 (0.3–11.3) years. Median age at follow-up was 5 (0.6–29) years old. Nineteen long-term survivors filled in the health-related quality of life questionnaires and were classified into three age groups: 0–4 years (n = 7): median health-related quality of life score, 69 (59–86) points; 4–12 years (n = 7): median health-related quality of life score, 50 (48–85) points; older than 12 years (n = 5): median health-related quality of life score, 90 (80–100) points. Conclusion: Long-term survivors’ health-related quality of life as reported by their parents is lower than that of healthy children. However, the self-assessed health-related quality of life of the patients older than 12 years in our group is comparable to a healthy control population.


Interactive Cardiovascular and Thoracic Surgery | 2015

No-React® Injectable BioPulmonic™ valves re-evaluated: discouraging follow-up results

Jochen Grohmann; René Höhn; Thilo Fleck; Brigitte Stiller; Elena Neumann; Matthias Sigler; Johannes Kroll; Friedhelm Beyersdorf; Matthias Siepe

OBJECTIVES The No-React® Injectable BioPulmonic™ valve (BioIntegral) was introduced for minimally invasive off-pump replacement of the pulmonary valve almost 10 years ago. We present our mid- to long-term follow-up results. METHODS We conducted a retrospective analysis of all 7 patients treated at our institution at the median age of 9 (range 1-24) years. The children underwent cardiac catheterization when worsening strain on the right heart was suspected after examining their medical history and/or observing significant changes on echocardiography. RESULTS After a median follow-up period lasting 5.2 (range 0.7-6.7) years, all patients presented the indication for recatheterization, particularly because the maximum instantaneous velocity measured by Doppler had revealed systolic gradients of a median 63 (dP 18-74) mmHg across the right ventricular outflow. Catheterization confirmed severe stenosis in 2, and moderate stenosis together with moderate insufficiency in 4 patients. We observed two principal failure mechanisms: technical problems resulting from poor alignment to the right ventricular outflow tract and structural problems leading to neointimal proliferation even in cases with appropriate prosthesis positioning. At median of 5.7 (0.7-7) years after implantation, 6 of the 7 patients underwent valve rereplacement. Redo surgery was necessary in 3, and percutaneous valve-in-valve implantation in the remaining 3 patients. Histological analysis of two explanted valves confirmed significant neointima proliferation and thickened valve cusps leading to stenosis of the graft. CONCLUSIONS These mid-term results after implantation of the No-React® Injectable BioPulmonic™ valve are disappointing. Graft failure was mainly due to neointimal formation and valve malposition.


Artificial Organs | 2018

Implementing and Assessing a Standardized Protocol for Weaning Children Successfully From Extracorporeal Life Support: STANDARDIZED WEANING CHILDREN FROM ECLS

Rouven Kubicki; René Höhn; Jochen Grohmann; Thilo Fleck; Katja Reineker; Johannes Kroll; Matthias Siepe; Christoph Benk; Rolf Klemm; Frank Humburger; Brigitte Stiller

Extracorporeal life support (ECLS) weaning is a complex interdisciplinary process with no clear guidelines. To assess ventricular and pulmonary function as well as hemodynamics including end-organ recovery during ECLS weaning, we developed a standardized weaning protocol. We reviewed our experience 2 years later to assess its feasibility and efficacy. In 2015 we established an inter-professional, standardized, stepwise protocol for weaning from ECLS. If the patient did not require further surgery, weaning was conducted bedside in the intensive care unit (ICU). Most of the weaning procedures are guided via echocardiography. Data acquisition began at baseline level, followed by four-step course (each step lasting 10 min), entailing flow-reduction and ending 30 min after decannulation. Moreover, data from the preprotocol era are presented. Between May 2015 and 2017, 26 consecutive patients (18 male), median age 177 days (2 days-20 years) required ECLS with median support of 4 (2-11) days. Excluding eight not weanable patients, 21 standardized weaning procedures were protocolled in the remaining 18 children. Our generally successful protocol-guided weaning rate (with at least 24-h survival) was 89%, with a discharge home rate of 58%. Practical application of the novel standard protocol seems to facilitate ECLS weaning and to improve its success rate. The protocol can be administered as part of standard bedside ICU assessment.


World Journal of Cardiology | 2017

Dysphagia after arteria lusoria dextra surgery: Anatomical considerations before redo-surgery

Judith Mayer; Natascha van der Werf-Grohmann; Johannes Kroll; Ute Spiekerkoetter; Brigitte Stiller; Jochen Grohmann

Aberrant right subclavian artery (arteria lusoria) is the most common congenital root anomaly, remaining asymptomatic in most cases. Nevertheless, some of the 20%-40% of those affected present tracheo-esophageal symptoms. We report on a 6-year-old previously healthy girl presenting with progressive dysphagia over 4 wk. Diagnostics including barium swallow, echocardiography and magnetic resonance angiography (MRA) revealed a retro-esophageal compression by an aberrant right subclavian artery. Despite the successful, uneventful transposition of this arteria lusoria to the right common carotid via right-sided thoracotomy, the girl was suffering from persisting dysphagia. Another barium swallow showed the persistent compression of the esophagus on the level where the arteria lusoria had originated. As MRA showed no evidence of a significant re-obstruction by the transected vascular stump, we suspected a persisting ligamentum arteriosum. After a second surgical intervention via left-sided thoracotomy consisting of transecting the obviously persisting ligamentum and shortening the remaining arterial stump of the aberrant right subclavian artery, the patient recovered fully. In this case report we discuss the potential relevance of a persisting ligamentum arteriosum for patients with left aortic arch suffering from dysphagia lusoria and rational means of diagnosing, as well as the surgical options to prevent re-do surgery.


The Annals of Thoracic Surgery | 2017

Primary Coiling of the Left Ventricle in Hypoplastic Left Heart With Ventriculo-Coronary Connections

Johanna Hummel; Brigitte Stiller; Johannes Kroll; Jochen Grohmann

n hypoplastic left heart syndrome (HLHS), the signifiIcance of anatomic variants on outcome remains controversial [1, 2]. The HLHS subtype with mitral stenosis and aortic atresia (MS-AA) was recently associated with the highest mortality [1]. Ventriculo-coronary connections (VCCs) are exclusively found in conjunction with MS-AA. Thus, coronary steal via VCCs may be considered the main risk factor for the poorest outcomes (Fig 1: [A] bidirectional VCC-flow; [B] left coronary reverse flow; Video 1). We describe a novel hybrid approach during Norwood stage 1 palliation to limit coronary runoff; an end-hole catheter is introduced under visual control through the opened atria and mitral valve into the left ventricle. Guided by echocardiography, a microcoil system (off-label) is deployed until the cavity is tightly packed (Video 2). This is a causal approach toward VCC-related coronary runoff that can be considered in


Thoracic and Cardiovascular Surgeon | 2016

No-React® Injectable BioPulmonic™ Valves Re-evaluated: Discouraging Follow-up Results

Matthias Siepe; R. Höhn; Thilo Fleck; Brigitte Stiller; E. Neumann; M. Sigler; Johannes Kroll; Friedhelm Beyersdorf; Jochen Grohmann

OBJECTIVES: The No-React® Injectable BioPulmonicTM valve (BioIntegral) was introduced for minimally invasive off-pump replacement of the pulmonary valve almost 10 years ago. We present our midto long-term follow-up results. METHODS: We conducted a retrospective analysis of all 7 patients treated at our institution at the median age of 9 (range 1–24) years. The children underwent cardiac catheterization when worsening strain on the right heart was suspected after examining their medical history and/or observing significant changes on echocardiography. RESULTS: After a median follow-up period lasting 5.2 (range 0.7–6.7) years, all patients presented the indication for recatheterization, particularly because the maximum instantaneous velocity measured by Doppler had revealed systolic gradients of a median 63 (dP 18–74) mmHg across the right ventricular outflow. Catheterization confirmed severe stenosis in 2, and moderate stenosis together with moderate insufficiency in 4 patients. We observed two principal failure mechanisms: technical problems resulting from poor alignment to the right ventricular outflow tract and structural problems leading to neointimal proliferation even in cases with appropriate prosthesis positioning. At median of 5.7 (0.7–7) years after implantation, 6 of the 7 patients underwent valve rereplacement. Redo surgery was necessary in 3, and percutaneous valve-in-valve implantation in the remaining 3 patients. Histological analysis of two explanted valves confirmed significant neointima proliferation and thickened valve cusps leading to stenosis of the graft. CONCLUSIONS: These mid-term results after implantation of the No-React® Injectable BioPulmonicTM valve are disappointing. Graft failure was mainly due to neointimal formation and valve malposition.


The Thoracic & Cardiovascular Surgeon Reports | 2016

A Technical Modification for Establishing Selective Antegrade Cerebral Perfusion during Pulmonary Endarterectomy

Martin Czerny; Patrick von Samson; Bernward Passlick; Friedhelm Beyersdorf; Johannes Kroll

Pulmonary endarterectomy (PEA) due to chronic thromboembolic pulmonary hypertension (CTEPH) is mainly performed in deep hypothermic circulatory arrest without additional cerebroprotective means. A 49-year-old man was treated by PEA for CTEPH by using selective antegrade cerebral perfusion by advancing the tip of the systemic perfusion cannula into the brachiocephalic trunk. The postoperative course was uneventful.

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Thilo Fleck

University of Freiburg

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René Höhn

University of Freiburg

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Rolf Klemm

University of Freiburg

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