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Dive into the research topics where Tim Kaufeld is active.

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Featured researches published by Tim Kaufeld.


European Journal of Cardio-Thoracic Surgery | 2016

Do not leave the heart arrested. Non-cardioplegic continuous myocardial perfusion during complex aortic arch repair improves cardiac outcome

Andreas Martens; Nurbol Koigeldiyev; Erik Beckmann; Felix Fleissner; Tim Kaufeld; Heike Krueger; Detlev Stanelle; Jakob Puntigam; Axel Haverich; Malakh Shrestha

OBJECTIVES Myocardial protection with cardioplegia alone may be inadequate during complex aortic arch surgery, potentially resulting in postoperative myocardial insufficiency. We hypothesized that non-cardioplegic continuous myocardial perfusion (CMP) is feasible and safe to protect the heart while operating on the aortic arch, and improves cardiac outcome. METHODS Between April 2010 and April 2014, 144 patients (60% male, age: 60 ± 13 years) underwent complex aortic arch repair in our institution using prefabricated, branched aortic arch grafts. In 36 patients, the hearts were protected with a combination of cardioplegic cardiac arrest during cardiac procedures and subsequent non-cardioplegic CMP group during aortic arch repair. In 108 patients, myocardial protection was achieved by cardioplegic arrest (CA group) only. RESULTS Preoperative risk factors were comparable in both groups. Acute aortic dissection was the indication for surgery in 42% (CMP) and 44% (CA) of patients; 22% (CMP) and 29% (CA) of patients underwent reoperations. Concomitant cardiac procedures were similar. CMP patients received a frozen elephant trunk more frequently (89 vs 66%, P = 0.0096). Cardiopulmonary bypass time (242 ± 50 vs 264 ± 68 min; P = 0.046), and cardiac ischaemic time (49 ± 32 vs 149 ± 56 min, P < 0.0001) were significantly lower in the CMP group. There were no conversions to CA in the CMP group. Aortic arch repair was not prolonged by CMP. Low cardiac output syndrome occurred less frequently in the CMP group (3 vs 22%, P = 0.0052). Thirty-day mortality was significantly lower in the CMP group (6 vs 21%, P = 0.040). There were no cardiac deaths in the CMP group (0 vs 9%, P = 0.067). Neurological outcome was comparable. Blood loss was higher in the CA group (P < 0.001). CONCLUSIONS Routinely protecting the heart during complex aortic arch repair with non-cardioplegic CMP is a valuable new concept. The CMP technique is feasible and safe, does not prolong aortic arch repair, reduces myocardial damage and improves cardiac outcome. Further evaluation in a larger patient cohort is warranted to establish this novel technique.


Journal of Heart and Lung Transplantation | 2015

Survival and spirometry outcomes after lung transplantation from donors aged 70 years and older

W. Sommer; F. Ius; J. Salman; M. Avsar; I. Tudorache; C. Kühn; Bettina Wiegmann; Georg Marsch; Tim Kaufeld; Norman Zinne; Thomas Fuehner; Mark Greer; Jens Gottlieb; Dietmar Boethig; Axel Haverich; Tobias Welte; G. Warnecke

BACKGROUND Mediocre donation rates and increasing demand for lung transplantation leads transplant centers to consider extended-criteria donor lungs. Arguably, the largest remaining non-utilized lung donor segment is the elderly individual, already considered for visceral organ donation but not thoracic. So far, transplantation of donor lungs aged ≥ 70 years is rarely reported, and recipient outcomes are unknown. Accordingly, we report a single-center series of lung transplantations from donors aged ≥ 70 years and compare outcomes with contemporary lung transplantations from younger donors. METHODS All bilateral lung transplantations performed at our center between March 2011 and July 2014 were analyzed, and 2 cohorts were built according to lung donor age. RESULTS A total of 440 bilateral lung transplantations were performed from 413 donors aged <70 years, and 27 donors aged ≥70 years. Donor characteristics did not differ in sex, donor time on mechanical ventilation before retrieval, or donor partial pressure of arterial oxygen/fraction of inspired oxygen ratio. Older donors were significantly less often positive for smoking history (43.7% vs 14.8%, p = 0.003) or for abnormal bronchoscopy results (52.9% vs 15.8%, p = 0.002). Recipients receiving donor lungs aged <70 years were younger than those receiving older donor lungs ≥ 70 (49.8 [range, 35-58] vs 58 [range, 53-62] years, p < 0.0001). Underlying diagnoses did not differ significantly between the groups. Post-operative mechanical ventilation times (15 [range, 10-59] vs 27.5 [range, 10-75.8] hours), intensive care unit stays (3 [range, 1-5] vs 3 [range, 1-8] days), and total hospital lengths of stay (24 [range, 22-40.5] vs 24 [range, 22-40] days) of the recipients did not differ significantly between the two groups. The percentage predicted forced expiratory volume in 1 second was 86.5% ± 26.2% 12 months after transplantation of younger lungs vs 72.2% ± 23.8% (p = 0.01) after transplantation of older lungs. Differentiating the spirometry findings according to underlying diseases showed significantly lower forced expiratory volume in 1 second values after transplantation of donor lungs aged ≥70 only in idiopathic pulmonary fibrosis recipients but not in emphysema patients. Patient survival up to 36 months was not significantly different, with 1-year survival being 92.9% for younger vs 95.5% for older donor lungs. CONCLUSION Use of donor lungs aged ≥70 years for transplantation is safe, without compromising survival. However, spirometry findings after transplantation with donors ≥70 years indicate better functional outcomes in emphysema recipients than in idiopathic pulmonary fibrosis recipients.


Interactive Cardiovascular and Thoracic Surgery | 2016

Aortic valve replacement with sutureless prosthesis: better than root enlargement to avoid patient-prosthesis mismatch?

Erik Beckmann; Andreas Martens; Firas Abd Alhadi; Klaus Hoeffler; Julia Umminger; Tim Kaufeld; Samir Sarikouch; Nurbol Koigeldiev; Serghei Cebotari; Jan D. Schmitto; Axel Haverich; Malakh Shrestha

OBJECTIVES Aortic valve replacement in patients with a small aortic annulus may result in patient-prosthesis mismatch (PPM). Aortic root enlargement (ARE) can reduce PPM, but leads to extended cardiac ischaemia times. Sutureless valves have the potential to prevent PPM while reducing cardiac ischaemia times. METHODS Between January 2007 and December 2011, a total of 128 patients with a small aortic annulus underwent surgery for aortic valve stenosis at our centre. Thirty-six (17% male, n = 6) patients received conventional valve replacement with ARE and 92 (16% male, n = 18) subjects received sutureless valve implantation (Sorin Perceval). We conducted a comparative, retrospective study with follow-up. RESULTS The sutureless group showed a significantly higher age (79 years) than the ARE patients (62 years, P < 0.001) and received significantly more concomitant cardiac procedures (33%, n = 30 vs 6%, n = 2, P = 0.001). The mean operation, cardiopulmonary bypass and cross-clamp times were significantly lower in sutureless patients (147 ± 42, 67 ± 26 and 35 ± 13 min, respectively) than in ARE patients (181 ± 41, 105 ± 29 and 70 ± 19 min, respectively, P < 0.001). The mean postoperative effective orifice area (EOA) indexed to the body surface area was 0.91 ± 0.2 cm(2)/m(2) in ARE patients and 0.83 ± 0.14 cm(2)/m(2) in sutureless patients (P = 0.040). The rate of patients with severe PPM was 6% (n = 2) in ARE patients and 11% (n = 8%) in sutureless patients (not significant, n.s.). The 30-day mortality rates were 2% (n = 2) in sutureless patients and 6% (n = 2) in ARE patients (n.s.). The 1- and 5-year survival rates of the sutureless group were 92 and 54% years, respectively, whereas the 1- and 5-year survival rates of the ARE group were 76% (n.s.). CONCLUSIONS Although the sutureless valve patients received significantly more concomitant procedures, all operation-associated times were significantly shorter. Despite sutureless valve patients being older, the 30-day mortality and survival rates were comparable in the two groups. Since the indexed EOA was only slightly lower and the incidence of severe PPM was not significantly higher in the sutureless valve patients, we conclude that sutureless valve implantation is an alternative to conventional ARE to treat a small aortic annulus and avoid PPM, especially in geriatric patients who benefit from the quick implantation process.


Artificial Organs | 2015

Cardiac awake extracorporeal life support-bridge to decision?

W. Sommer; Georg Marsch; Tim Kaufeld; Philipp Röntgen; Gernot Beutel; Joern Tongers; G. Warnecke; I. Tudorache; Bernhard Schieffer; Axel Haverich; C. Kühn

Severe acute heart failure requires immediate intensive care unit (ICU) treatment, but prognosis and outcome of further treatment regimens largely depends on the preprocedural status of the patient. Especially, multiorgan failure including mechanical ventilation are unfavorable predictors of clinical outcome. Here, we report a strategy of immediate initiation of extracorporeal life support (ECLS) in awake and spontaneously breathing patients with acute heart failure to achieve early multiorgan recovery and gain sufficient time for further treatment planning. Twenty-three patients with severe cardiac failure refractory to standard medical management underwent ECLS treatment, after first clinical signs of cardiac failure appeared to avoid mechanical ventilation. Hemodynamic parameters and renal and liver functions were monitored. Outcome at 1 and 6 months was determined. Patients 46.1 ± 15.5 years of age were placed on ECLS due to various underlying diagnosis: ischemic heart disease (n = 6), dilatative cardiomyopathy (n = 4), myocarditis (n = 2), graft failure following heart transplantation (n = 6), or other diseases (n = 5). ECLS lasted 11.9 ± 12.9 days. Hemodynamic stabilization was achieved immediately after ECLS initiation. Vasopressors were reduced subsequently and the cardiac situation improved indicated by central venous saturation, which increased from 38.5 ± 11.3% before to 74.26 ± 8.4% (P < 0.0001) 24 h after ECLS initiation. Similarly, serum lactate levels decreased from 4.7 ± 4.6 to 1.7 ± 1.51 mmol/L (P = 0.003). Cumulative 30-day survival was 87.5%, and 6-month survival was 70.8%. In acute cardiac failure, early ECLS treatment is a safe, feasible treatment in awake patients allowing a gain of time for final decision. Moreover, this strategy avoids complications associated with sedation and mechanical ventilation and leads to recovery of secondary organ function, enabling destination therapy.


European Journal of Cardio-Thoracic Surgery | 2017

Single-centre experience with the frozen elephant trunk technique in 251 patients over 15 years

Malakh Shrestha; Andreas Martens; Tim Kaufeld; Erik Beckmann; Sebastian Bertele; Heike Krueger; Julia Neuser; Felix Fleissner; F. Ius; Firas Abd Alhadi; Jasmin S. Hanke; Jan D. Schmitto; Serghei Cebotari; Matthias Karck; Axel Haverich; Ajay Chavan

OBJECTIVES Our goal was to present our 15-year experience (2001-2015) with the frozen elephant trunk (FET) technique. METHODS A total of 251 patients (82 with aortic aneurysms, 96 with acute aortic dissection type A, 4 with acute type B dissections, 52 with chronic aortic dissection type A, 17 with chronic type B dissection and 67 redo cases) underwent FET implantation with either the custom-made Chavan-Haverich (n = 66), the Jotec E-vita (n = 31) or the Vascutek Thoraflex hybrid (n = 154) prosthesis. The cases were assigned to an early period (2001-2011) and a contemporary period (2012-present). RESULTS Mean cardiopulmonary bypass time, aortic cross-clamp time, circulatory arrest time and selective antegrade cerebral perfusion time were 241 ± 72, 125 ± 59, 56 ± 30 and 81 ± 34 min, respectively. Incidence of rethoracotomy for bleeding, stroke, spinal cord injury, prolonged ventilatory support (>96 h) and long-term dialysis were 18, 14, 2, 24 and 2%, respectively. The in-hospital mortality rate was 11% (in acute aortic dissection type A, 12%). Of the 2 patients with graft infections, 1 died and the other had a protracted hospital stay. There were 49 second-stage procedures in the downstream aorta: either open surgical [n = 25 (thoraco-abdominal, n = 15; descending, n = 6; infrarenal, n = 4)] or transfemoral endovascular (n = 23). Elective thoracic endovascular aneurysm repair R implantation was successful in all 23 cases. CONCLUSIONS FET results are comparable with those of the published results of the conventional elephant trunk technique. FET is an ideal landing zone for subsequent transfemoral endovascular completion. Patients with graft infections may have dismal results.


European Journal of Cardio-Thoracic Surgery | 2017

Valve-sparing David I procedure in acute aortic type A dissection: a 20-year experience with more than 100 patients†

Erik Beckmann; Andreas Martens; Jana Pertz; Tim Kaufeld; Julia Umminger; Jasmin S. Hanke; Jan D. Schmitto; Serghei Cebotari; Axel Haverich; Malakh Shrestha

OBJECTIVES The aortic valve-sparing David procedure has been applied to the elective treatment of patients with aortic aneurysms with excellent results. The use of this technique in patients with acute aortic dissection type A (AADA) is still a matter of debate. We present our long-term experience with 109 patients with AADA who had the valve-sparing David I procedure. METHODS Between July 1993 and October 2015, 109 patients with AADA had the valve-sparing David I procedure at our centre. We conducted a retrospective review with follow-up. RESULTS The mean age was 54 ± 12 years; 78 (72%) patients were men. Marfan syndrome was present in 6 (5%) patients and bicuspid aortic valve in 3 (3%). Only 4 (4%) patients received the isolated David procedure; 50 (46%) underwent additional proximal, 13 (12%) subtotal and 42 (39%) total aortic arch replacement. The in-hospital mortality rate was 11% ( n  = 12). Intraoperative/discharge echocardiography showed aortic insufficiency ≤ I° in 93 of 97 patients (96%). Mean follow-up time was 8.3 ± 5.7 years. The survival rate after discharge at 1, 5 and 10 years was 94%, 90% and 78%, respectively. Thirteen percent ( n  = 13) of patients underwent valve-related reoperation. Freedom from valve-related reoperation at 1, 5 and 10 years was 96%, 88% and 85%, respectively. Compared to patients who underwent the David I procedure for any reason other than AADA, there were no significant differences in long-term survival rates ( P  = 0.29) and freedom from a valve-related reoperation ( P  = 0.39). CONCLUSIONS The valve-sparing David I procedure has acceptable long-term results even in emergent operations for AADA and is not inferior when performed in elective settings.


European Journal of Cardio-Thoracic Surgery | 2017

Is the frozen elephant trunk procedure superior to the conventional elephant trunk procedure for completion of the second stage

Saad Rustum; Erik Beckmann; Mathias Wilhelmi; Heike Krueger; Tim Kaufeld; Julia Umminger; Axel Haverich; Andreas Martens; Malakh Shrestha

OBJECTIVES Our goal was to compare the results and outcomes of second‐stage completion in patients who had previously undergone the elephant trunk (ET) or the frozen elephant trunk (FET) procedure for the treatment of complex aortic arch and descending aortic disease. METHODS Between August 2001 and December 2014, 53 patients [mean age 61 ± 13 years, 64% (n = 34) male] underwent a second‐stage completion procedure. Of these patients, 32% (n = 17) had a previous ET procedure and 68% (n = 36) a previous FET procedure as a first‐stage procedure. RESULTS The median times to the second‐stage procedure were 7 (0‐78) months in the ET group and 8 (0‐66) months in the FET group. The second‐stage procedure included thoracic endovascular aortic repair in 53% (n = 28) of patients and open surgical repair in 47% (n = 25). More endovascular interventions were performed in FET patients (61%, n = 22) than in the ET group (35%, n = 6, P = 0.117). The in‐hospital mortality rate was significantly lower in the FET (8%, n = 3) group compared with the ET group (29%, n = 5, P = 0.045). The median follow‐up time after the second‐stage operation for the entire cohort was 4.6 (0.4‐10.4) years. The 5‐year survival rate was 76% in the ET patients versus 89% in the FET patients (log‐rank: P = 0.11). CONCLUSIONS We observed a significantly lower in‐hospital mortality rate in the FET group compared to the ET group. This result might be explained by the higher rate of endovascular completion in the FET group. We assume that the FET procedure offers the benefit of a more ideal landing zone, thus facilitating endovascular completion.


Revista Espanola De Cardiologia | 2018

Prognostic Value of the Nutritional Risk Index in Candidates for Continuous Flow Left Ventricular Assist Device Therapy

Aitor Uribarri; Sebastian V. Rojas; Jasmin S. Hanke; Günes Dogan; T. Siemeni; Tim Kaufeld; F. Ius; Tobias Goecke; Sara Rojas-Hernandez; G. Warnecke; Christoph Bara; M. Avsar; Axel Haverich

INTRODUCTION AND OBJECTIVES Malnutrition has been shown to affect clinical outcomes in patients with heart failure. The aim of this study was to analyze the impact of preoperative nutritional status assessed by the nutritional risk index (NRI) on the prognosis of patients with a continuous-flow left ventricular assist device (cf-LVAD). METHODS We performed a retrospective study of 279 patients who underwent cf-LVAD implantation between 2009 and 2015 in our center. Preoperative NRI was calculated and the patients were followed-up for 1 year. The association between preoperative NRI and postoperative clinical events was analyzed using multivariable logistic regression. RESULTS The prevalence of severe (NRI <83.5), moderate (83.5 ≤ NRI <97.5) and mild (97.5 ≤ NRI <100) nutritional risk was 5.4%, 21.5%, and 9.3%. Mortality rates 1 year after cf-LVAD implantation in these 3 categories were 53.3%, 31.7%, 23.1% vs 18.0% (P <.001) in patients with a normal IRN. A normal preoperative NRI value was an independent predictor of lower risk of death from any cause during follow-up (aHR per 1 unit, 0.961; 95%CI, 0.941-0.981; P <.001) was and a predictor for a lower risk of postoperative infections (aOR, 0.968; 95%CI, 0.946-0.991; P=.007), respiratory failure (aOR, 0,961; 95%CI, 0.936-0.987; P=.004), and right heart failure (aOR, 0.963; 95%CI, 0.934-0.992; P=.014). CONCLUSIONS Malnourished patients are at increased risk for postoperative complications and death after cf-LVAD implantation. Assessment of nutritional risk could improve patient selection and the early initiation of nutritional support.


European Journal of Cardio-Thoracic Surgery | 2018

Valve-sparing aortic root replacement (David I procedure) in Marfan disease: single-centre 20-year experience in more than 100 patients†

Andreas Martens; Erik Beckmann; Tim Kaufeld; Felix Fleissner; Julia Neuser; Wilhelm Korte; Constanze Merz; Heike Krueger; Axel Haverich; Malakh Shrestha

OBJECTIVES Valve-sparing aortic root replacement (VSARR) is recommended for patients with aortic root dilatation and preserved aortic valve cusp morphology. The durability of VSARR in Marfan patients has been questioned. The aim of our study was to establish the long-term outcomes of VSARR in Marfan patients. METHODS Between 1993 and 2015, 582 patients underwent VSARR (David I reimplantation) at our institution. Of these patients, 104 had Marfan disease. Thirteen surgeons performed the procedures in this group. The mean follow-up time was 12 ± 5.4 years (1201 patient-years). RESULTS Early mortality was 0.96%, and long-term survival was 91% at 10 years and 76% at 20 years in Marfan patients. Marfan patients had a significantly better survival compared to non-Marfan patients (P < 0.0001). Freedom from aortic-valve reoperation was 86% at 10 years and 80% at 20 years in Marfan patients. The reoperation rate was similar in Marfan and non-Marfan patients (P = 0.60). Morphological perioperative features (untreated prolapse, commissural plasty, cusp plasty and graft size mismatch) predicted long-term mortality (P = 0.0054). Graft size mismatch and untreated prolapse predicted structural valve deterioration (both P < 0.0001). Long-term valve function in event-free survivors was excellent [mean gradient 4.2 (2.9-6.9), 98% aortic regurgitation ≤ mild]. There were no valve-related thromboembolic or bleeding events. The endocarditis rate was 0.96%. Only 17% of the patients were on oral anticoagulants during the follow-up. CONCLUSIONS VSARR using the David I reimplantation technique results in excellent long-term outcomes in Marfan patients. We present the longest follow-up period so far. The genetic disease does not affect long-term valve function. The durability of the repair is affected by morphological perioperative criteria depending on surgical expertise, and dedicated training is recommended.


The Annals of Thoracic Surgery | 2016

A Close Call: An Impacted Knife Injury to the Thorax

Tim Kaufeld; Christian Zeckey; Steffen Marquardt; Christian Krettek; Axel Haverich; I. Tudorache

A 21-year-old woman with a history of psychiatric treatment was admitted to the emergency department with self-inflicted stab wounds to the neck, chest, and abdomen as the result of a suicide attempt. Inspection showed a seemingly superficial cut at the jugular fossa. The patients mother stated that one long ceramic kitchen bread knife was totally embedded in the right thorax. Further diagnostic measures showed the missing kitchen bread knife penetrating the right chest, with the path of insertion starting 2 cm above the right clavicle and the blade in contact with the right hilum and ending next to the seventh thoracic vertebra. Retrieval the object was a challenging problem.

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F. Ius

Hannover Medical School

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G. Warnecke

Hannover Medical School

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M. Avsar

Hannover Medical School

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