Lars Oliver Conzelmann
University of Mainz
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Featured researches published by Lars Oliver Conzelmann.
The Annals of Thoracic Surgery | 2009
Lars Oliver Conzelmann; N Kayhan; U Mehlhorn; Ernst Weigang; Manfred Dahm; Christian F. Vahl
BACKGROUNDnThe optimal mode of arterial cannulation in acute type A aortic dissection is controversial. We retrospectively investigated our experience with direct true lumen cannulation as an alternative to standard cannulation procedures.nnnMETHODSnFrom April 2004 to August 2007, 29 patients (20 men, 9 women; mean age of 63.2 +/- 12.6 years) underwent emergency operation for acute type A aortic dissection with direct true lumen cannulation. After venous drainage into the venous reservoir, the ascending aorta was completely transected in the region between the sinotubular junction and innominate artery. After visual and digital identification of the true lumen, the arterial cannula was directly inserted into the true lumen and secured with a ligature.nnnRESULTSnMean aortic cross-clamp time was 77.4 +/- 28.3 minutes, and hypothermic circulatory arrest for the distal anastomosis was 10.4 +/- 11.0 minutes. All patients survived the surgical procedure. No surgical problems were observed by applying this strategy. Mean intensive care unit stay was 4.0 +/- 3.5 days. Postoperative mean ventilation time was 43.3 +/- 41.3 hours. One patient had a prolonged postoperative course and required permanent ventilation. Two patients required temporary hemofiltration. Neurologic disorders occurred in 6 patients: 2 had severe cerebral hypoxia, and 4 had temporary hemiplegia under good regression. All patients were alive at discharge.nnnCONCLUSIONSnDirect true lumen cannulation is a promising surgical strategy for emergency operations in type A aortic dissection. It is a simple, quick, and safe method to provide antegrade flow through the true aortic lumen.
European Journal of Cardio-Thoracic Surgery | 2016
Lars Oliver Conzelmann; Ernst Weigang; Uwe Mehlhorn; Ahmad Abugameh; Isabell Hoffmann; Maria Blettner; Christian D. Etz; Martin Czerny; Christian F. Vahl
OBJECTIVESnAcute aortic dissection type A (AADA) is an emergency with excessive mortality if surgery is delayed. Knowledge about independent predictors of mortality on surgically treated AADA patients is scarce. Therefore, this study was conducted to identify pre- and intraoperative risk factors for death.nnnMETHODSnBetween July 2006 and June 2010, 2137 surgically treated patients with AADA were enrolled in a multicentre, prospective German Registry for Acute Aortic Dissection type A (GERAADA), presenting perioperative status, operative strategies, postoperative outcomes and AADA-related risk factors for death. Multiple logistic regression analysis was performed to identify the influence of different parameters on 30-day mortality.nnnRESULTSnOverall 30-day mortality (16.9%) increased with age [adjusted odds ratio (OR) = 1.121] and among patients who were comatose (adjusted OR = 3.501) or those who underwent cardiopulmonary resuscitation (adjusted OR = 3.751; all P < 0.0001). The higher the number of organs that were malperfused, the risk for death was (adjusted OR for one organ = 1.651, two organs = 2.440, three organs or more = 3.393, P < 0.0001). Mortality increased with longer operating times (total, cardiopulmonary bypass, cardiac ischaemia and circulatory arrest; all P < 0.02). Arterial cannulation site for extracorporeal circulation, operative techniques and arch interventions had no significant impact on 30-day mortality (all P > 0.1). No significant risk factors, but relevant increases in mortality, were determined in patients suffering from hemiparesis pre- and postoperatively (each P < 0.01), and in patients experiencing paraparesis after surgery (P < 0.02).nnnCONCLUSIONSnGERAADA could detect significant disease- and surgery-related risk factors for death in AADA, influencing the outcome of surgically treated AADA patients. Comatose and resuscitated patients have the poorest outcome. Cannulation sites and operative techniques did not seem to affect mortality. Short operative times are associated with better outcomes.
Critical Care | 2008
N Kayhan; Benjamin Funke; Lars Oliver Conzelmann; Harald Winkler; Stefan Hofer; Jochen Steppan; Heinfried Schmidt; Hubert J. Bardenheuer; Cf Vahl; Markus A. Weigand
IntroductionThe treatment of septic conditions in critically ill patients is still one of medicines major challenges. Cyclic nucleotides, adenosine and its receptors play a pivotal role in the regulation of inflammatory responses and in limiting inflammatory tissue destruction. The aim of this study was to verify the hypothesis that adenosine deaminase-1 and cyclic guanosine monophosphate-stimulated phosphodiesterase inhibition by erythro-9-[2-hydroxyl-3-nonyl]-adenine could be beneficial in experimental endotoxicosis/sepsis.MethodWe used two established animal models for endotoxicosis and sepsis. Twenty-four male Wistar rats that had been given intravenous endotoxin (Escherichia coli lipopolysaccharide) were treated with either erythro-9-[2-hydroxyl-3-nonyl]-adenine infusion or 0.9% saline during a study length of 120 minutes. Sepsis in 84 female C57BL/6 mice was induced by caecal ligation and puncture. Animals were treated with repeated erythro-9-[2-hydroxyl-3-nonyl]-adenine injections after 0, 12 and 24 hours or 4, 12 and 24 hours for delayed treatment.ResultsIn endotoxaemic rats, intestinal production of hypoxanthine increased from 9.8 +/- 90.2 μmol/l at baseline to 411.4 +/- 124.6 μmol/l and uric acid formation increased from 1.5 +/- 2.3 mmol/l to 13.1 +/- 2.7 mmol/l after 120 minutes. In endotoxaemic animals treated with erythro-9-[2-hydroxyl-3-nonyl]-adenine, we found no elevation of adenosine metabolites. The lactulose/L-rhamnose ratio (14.3 versus 4.2 in control animals; p = 2.5 × 10-7) reflects a highly permeable small intestine and through the application of erythro-9-[2-hydroxyl-3-nonyl]-adenine, intestinal permeability could be re-established. The lipopolysaccharide animals had decreased L-rhamnose/3-O-methyl-D-glucose urine excretion ratios. Erythro-9-[2-hydroxyl-3-nonyl]-adenine reduced this effect. The mucosa damage score of the septic animals was higher compared with control and therapy animals (p < 0.05). Septic shock induction by caecal ligation and puncture resulted in a 160-hour survival rate of about 25%. In contrast, direct adenosine deaminase-1 inhibition resulted in a survival rate of about 75% (p = 0.0018). A protective effect was still present when erythro-9-[2-hydroxyl-3-nonyl]-adenine treatment was delayed for four hours (55%, p = 0.029).ConclusionsWe present further evidence of the beneficial effects achieved by administering erythro-9-[2-hydroxyl-3-nonyl]-adenine, an adenosine deaminase-1 and cyclic guanosine monophosphate-stimulated phosphodiesterase inhibitor, in an endotoxicosis and sepsis animal model. This suggests a potential therapeutic option in the treatment of septic conditions.
Interactive Cardiovascular and Thoracic Surgery | 2012
Lars Oliver Conzelmann; Ernst Weigang; U Mehlhorn; Christian F. Vahl
In acute aortic dissection type A (AADA), direct true lumen cannulation (DTLC) of the ascending aorta is a fast and safe cannulation site providing antegrade perfusion of the supraaortic and visceral vessels. An Overholt clamp is passed around the ascending aorta to place a Mersilene tape for later securing of the arterial cannula. After draining venous blood into the cardiopulmonary bypass system (CPB), the ascending aorta is transected and the aortic lumen inspected. The true lumen is identified and an arterial cannula inserted directly. Finally, the cannula is secured with the previously placed tape and CPB is initiated. DTLC can be used as arterial cannulation standard technique in operations for AADA.
Zeitschrift für Herz-,Thorax- und Gefäßchirurgie | 2009
Lars Oliver Conzelmann; O. Dapunt; Klaus Kallenbach; Matthias Karck; Ernst Weigang
ZusammenfassungEin deutschsprachiges Register für akute Aortendissektionen Typxa0A (GERAADA) wurde von der Arbeitsgemeinschaft „Aortenchirurgie und interventionelle Gefäßchirurgie“ der DGTHG im Juli 2006 eingeführt. Diese web-basierte Datenbank wurde entwickelt, um Daten von Patienten zu erfassen, die wegen einer akuten Aortendissektion Typxa0A operiert wurden. Ziel war es, aus den analysierten Daten zu lernen, wie man die chirurgische Behandlung verbessern könnte und welche Parameter das Patienten-Outcome möglicherweise beeinflussen. Zu Beginn nahmen 33xa0deutsche Herzzentren über einen Online-Zugang zum Register auf der Homepage der DGTHG teil; mittlerweile sind es 43xa0Zentren. Es wurden Daten, die den prä- und intraoperativen Status der Patienten, postoperative Komplikationen, mittelfristige Ergebnisse und Todesursachen betrafen, eingebracht. Mittlerweile konnten aus dem Register erste Ergebnisse und Trends abgeleitet werden, die allen teilnehmenden Zentren zur Verfügung stehen. Mittelfristig können alle Zentren von dem gemeinsamen Datenpool profitieren und ihr Therapieregime bei ihren Patienten kontinuierlich optimieren und den eigenen Erfolg, in Relation zum Gesamtkollektiv, mit Hilfe des Registers vergleichen.AbstractA German-language registry for acute aortic dissection type A (GERAADA) was set up by the working group for aortic surgery and interventional vascular surgery of the GSTCS in July 2006. This web-based database was developed to record data of patients who had undergone surgery for aortic dissections type A. The aim was to learn from analysing the data how to improve surgical treatment and to identify possible parameters affecting patient outcome. Initially, 33 German cardiac surgery centres participated via online access to the registry on the GSTCS’ homepage; meanwhile, there are 43 participating centres. Data concerning pre- and intra-operative status of patients, post-operative complications, mid-term results and circumstances of death have been recorded. Initial results and trends could be derived from the register, which are now available to all participating centres. All centres can benefit from this shared pool of registered data by continuously optimising their therapy regimes and comparing their success with that seen at other participating centres.
The Annals of Thoracic Surgery | 2011
Lars Oliver Conzelmann; U Mehlhorn; Ernst Weigang; N Kayhan; Christian F. Vahl
A 46-year-old man presented to the emergency room with pain in his left leg, dyspnea, and general cyanosis. During examination he collapsed and required resuscitation. Under suspicion of pulmonary embolism, a new portable click n run extracorporeal life support system (LIFEBRIDGE-B(2)T [Medizintechnik AG, Ampfing, Germany]) was implanted by the femoral vessels under resuscitation within 15 minutes of presentation. The patient was stabilized, despite severe decompensation (pH, 6.8), and could be transferred for a computed tomographic scan, which confirmed massive pulmonary embolism. Still connected to the life support system, the patient was transferred to the operating room. After a pulmonary thrombectomy was performed, the patient recovered without any organ dysfunction. A portable emergency extracorporeal life support may change clinical practice in the treatment of patients with severe hemodynamic deterioration at emergency care hospitals.
Clinical Research in Cardiology | 2017
Gerhard Schymik; Panagiotis Tzamalis; Valentin Herzberger; Jens Bergmann; Peter Bramlage; Alexander Würth; Lars Oliver Conzelmann; Armin Luik; Holger Schröfel
BackgroundPrevious studies into the effect of a reduced left ventricular ejection fraction (EF) on the short- and long-term prognosis of patients undergoing transcatheter aortic valve implantation (TAVI) have reported conflicting findings. We analysed data from the Karlsruhe TAVI registry with the aim of addressing this question.Methods and resultsPatients with aortic stenosis undergoing TAVI were divided into sub-groups according to EF: severely reduced (<30%; nxa0=xa0109), reduced (≥30 and ≤40%; nxa0=xa0201), and mid-range/preserved (>40%; nxa0=xa01690). VARC complications at 30xa0days for the population with severely reduced EF did not differ in comparison to the patients with mid-range/preserved EF. Patients with severely reduced EF had a significantly lower survival at 48xa0h (91.7 vs. 99.0%; pxa0<xa00.001), at 30xa0days (84.4 vs. 95.8%; pxa0<xa00.001) and at 1xa0year (66.1 vs. 85.0%, pxa0<xa00.001) compared to those with mid-range/preserved EF. The risk of death increased with age, peripheral arterial disease, poor self-care and chronic renal failure in patients with severely reduced EF.ConclusionsMortality post-TAVI was higher for patients with a reduced EF, although the excess comorbidity burden likely contributed to this. A reduced EF should not be considered a contraindication for TAVI per se, but the additional presence of comorbidity indicates increased risk for these patients.
European Journal of Cardio-Thoracic Surgery | 2016
Lars Oliver Conzelmann; Uwe Mehlhorn; Claus Schmitt; Gerhard Schymik
Coronary obstruction after valve-in-valve transcatheter aortic valve implantation: salvage with stent in the left main stem Lars Oliver Conzelmann*, Uwe Mehlhorn, Claus Schmitt and Gerhard Schymik a Department of Cardiac Surgery, HELIOS Clinics for Cardiac Surgery, Karlsruhe, Germany b Department of Cardiology, Medical Clinic IV, Municipal Hospital Karlsruhe, Academic Teaching Hospital of the University of Freiburg, Karlsruhe, Germany
European Journal of Cardio-Thoracic Surgery | 2018
Lars Oliver Conzelmann; Alexander Würth; Gerhard Schymik; Holger Schröfel; Tonic Anusic; Stefanie Temme; Panagiotis Tzamalis; Jan Gerhardus; Chirojit Mukherjee; Bernd-Dieter Gonska; Claus Schmitt; Uwe Mehlhorn
OBJECTIVESnTranscatheter aortic valve implantation (TAVI) in patients with low coronary heights is generally denied but is not impossible. Information about these high-risk procedures is sparse.nnnMETHODSnSince May 2008, data of more than 3000 patients who had TAVI were prospectively collected in the institutional TAVI Karlsruhe registry. Characteristics, peri- and postoperative outcome of patients with low coronary heights of ≤7u2009mm were analysed according to the Valve Academic Research Consortium-2.nnnRESULTSnEighty-six patients with an average coronary height of 6.4u2009±u20091.1u2009mm (mean age 81.0u2009±u20095.3u2009years, logistic EuroSCORE I 19.6u2009±u200913.3%) were treated. TAVI was performed in 72 transfemoral (83.7%) and 14 transapical (16.3%) cases using 44 CoreValve/Evolut R (51.2%), 21 Sapien XT/S3 (24.4%), 14 ACURATE (16.3%), 5 Lotus (5.8%) and 2 Portico (2.3%) prostheses. Ten procedures were valve-in-valve (VinV) TAVI (VinV, 11.6%). The 72-h, 30-day, 1-year and follow-up (3.0u2009±u20091.6u2009years) mortality rates were 2.3%, 8.0%, 10.5% and 26.7%, respectively. Within 30u2009days, 4 cardiac deaths and 3 non-cardiac deaths occurred (4.7% and 3.5%). Three coronary obstructions (3.5%) occurred-2 during VinV TAVI. One patient was connected to extracorporeal circulation that could not be weaned later due to an unsuccessful percutaneous coronary intervention. Another patient, the only conversion (1.2%), required delayed surgical valve replacement. The third patient died of right heart failure after aortic dissection. The procedural success rate was 95.3%. VinV procedures were associated with increased follow-up deaths (Pu2009<u20090.001; hazard ratio 7.96).nnnCONCLUSIONSnCoronary-related complications in TAVI procedures in patients with coronary heights ≤7u2009mm occurred less frequently, but once they occurred, they were serious. These TAVI procedures are feasible, with a high procedural success rate, but meticulous preoperative planning should be mandatory. In VinV procedures, the follow-up mortality rate is increased; therefore, we do not recommend these procedures.
BMJ Open | 2018
Gerhard Schymik; Valentin Herzberger; Jens Bergmann; Peter Bramlage; Lars Oliver Conzelmann; Alexander Würth; Armin Luik; Holger Schröfel; Panagiotis Tzamalis
Objectives Use of transcatheter aortic valve implantation (TAVI) to treat severe aortic stenosis (AS) has gained popularity, accompanied by an evolution of patient and clinical factors. We aimed to characterise changes and evaluate their impact on outcomes. Setting In this single-centre, German TAVIK registry patients undergoing TAVI between 2008 and 2015 were documented prospectively. Participants/interventions 2000 consecutive patients with AS undergoing TAVI were divided in four cohorts. 500 patients underwent TAVI in each of the following time bins: April 2008 to July 2010 (cohort I), July 2010 to April 2013 (cohort II), April 2012 to October 2013 (cohort III) and October 2013 to March 2015 (cohort IV). Results The mean age was 81.8 years, without significant variation across cohorts. Compared with cohort I, prior MI (5.4%vs11.0%; p<0.001) and New York Heart Association class IV (10.0%vs3.6%; p<0.001) were less common in cohort IV. Across cohorts, there was a fall in EuroSCORE (24.3%–18.7%), frailty (48.4%–17.0%) and use of transapical access (43.6%–29.0%), while transfemoral access increased (56.4%–71.0%; p<0.001 for each). Periprocedurally, there was a fall in moderate/severe aortic regurgitation (3.2%–0.0%) and rate of unplanned cardiopulmonary bypass (4.0%–1.0%; both p<0.001). A similar trend applied to 30-day rate of major vascular complications (5.2%–1.8%; p=0.006), life-threatening bleeding (7.0%–3.0%; p<0.001) and cardiovascular mortality (4.4%–1.8%; p=0.020). One-year post-TAVI, mortality and stroke rates did not differ. Conclusions Evolution of TAVI between 2008 and 2015 saw a trend towards its usage in lower risk patients and rapid progression towards improved safety. Evaluation and refinement should now continue to further lessen stroke and pacemaker rates.