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Biomedical subjects

Uwe Klima

Publications and source records attributed to Uwe Klima.

At least 19 recordsLinked to original sources
PubMed2006

Creatine kinase isoenzyme MB relative index as predictor of mortality on extracorporeal membrane oxygenation support for postcardiotomy cardiogenic shock in adult patients.

OBJECTIVE: Extracorporeal membrane oxygenation (ECMO) has been used as initial, biventricular circulatory support for patients with severe postcardiotomy cardiogenic shock (PCS). Due to its aggressiveness and limited weaning quote, concerns have been raised about maintenance of ECMO support regarding duration. However, it is frequently hazardous for physicians to make an individualized decision, whether and when discontinuation of ECMO support should be considered. We tried to find measurable values during ECMO support that could predict the patient mortality on ECMO support. METHODS: During a 9-year period, 32 patients (mean age 55.4+/-11.9; ranging from 30 to 75 years) with ECMO support for postcardiotomy cardiogenic shock were included in this study. RESULTS: Eighteen patients died without weaning (group I, 56.25%), while 14 patients could be weaned off the ECMO support (group II, 43.75%). In the group II, six patients (18.75%) died later in the postoperative course and eight patients (25%) survived to be discharged from hospital. The overall survival of all 32 patients at 30 days was 31.25% (n=10). At a follow-up period of 3.88+/-1.58 years, the overall survival rate was 12.5% (n=4). Mean duration of ECMO support was 2.7+/-1.7 days. The following variables were significantly different between the two groups: blood lactate level and the level of MB isoenzyme of creatine kinase (CK-MB) 48 h after ECMO initiation (p<0.01, p=0.001) as well as the CK-MB relative index as the ratio of CK-MB to total CK (p<0.001). Logistic regression identified that only the CK-MB relative index 48 h after ECMO initiation was associated with mortality on ECMO support (p=0.011, odds ratio=1.219, 95% confidence interval: 1.046-1.421). CONCLUSION: For adult non-transplantation patients with postcardiotomy cardiogenic shock, the CK-MB relative index 48 h after ECMO initiation can be a predictor of mortality on ECMO support. This might be a useful tool for considering a patient either for discontinuation of ECMO support or further treatment.

Adult↗
PubMed2006

Anastomotic obstruction after magnetic vascular coupling after minimally invasive direct coronary artery bypass grafting.

We report a 61-year-old man who required reoperation 8 months after minimally invasive direct coronary artery bypass grafting after magnetic vascular coupling due to a symptomatic subtotal obstruction at the anastomotic site. It was also determined that the patient had been noncompliant in following the prescribed postoperative antiplatelet therapy.

Anastomosis, Surgical↗
PubMed2006

Cerebral microembolization during antegrade selective cerebral perfusion.

BACKGROUND: This study quantified the number of intraoperative microemboli in patients undergoing aortic arch surgery using selective cerebral perfusion (SCP) in comparison with those in patients undergoing ascending aortic replacement without circulatory arrest and SCP. METHODS: A transcranial Doppler monitoring of the medial cerebral artery was performed in 15 patients undergoing proximal arch replacement with SCP (SCP group) and 15 patients undergoing replacement of the ascending aorta (control group). RESULTS: There was no significant difference in the high-intensity transient signal counts between the SCP group and the control group at any phase. In the SCP group, 4.8% of microemboli occurred during cross-clamping, and only 0.6% occurred during SCP. In the control group, 4.6% occurred during cross-clamping. Most microemboli occurred after removing the cross-clamps in both groups; 92.2% in the SCP group and 92.1% in the control group. CONCLUSIONS: The present study demonstrated that outbreak frequency of microemboli during SCP was very low, and thus implies that the risk of embolic event that may be caused by SCP is very low.

Aged↗
PubMed2006

Iatrogenic type A dissection after attempted stenting of a descending aortic aneurysm.

This case demonstrates an iatrogenic acute retrograde type A dissection of the aortic arch and ascending aorta during elective endovascular stenting of a proximal descending aortic aneurysm. This devastating complication necessitated emergent surgery with unfavorable postoperative outcome. Other than the known causes, the described retrograde type A dissection resulted from guidewire manipulation and iatrogenic creation of a false lumen, which was erroneously dilated and stented.

Aged↗
PubMed2006

Glycine application and right heart function in a porcine heart transplantation model.

Glycine reduces ischemia-reperfusion injury after experimental liver transplantation. We hypothesized that glycine might also protect right heart function in an isovolumic cardiac transplantation model. In six domestic donor pigs 150 ml of a 300 mmol L-glycine solution were administered intravenously. The hearts were then arrested with histidine-tryptophan-ketoglutarate solution. Animals without prior glycine infusion served as controls (n = 6). After 4 h of ischemia, hearts were transplanted into recipients. An isovolumic model was used in which the right ventricular (RV) volume was controlled in vivo using an intracavitary high-compliance balloon. After 1 and 2 h of reperfusion the RV balloon volume was gradually increased and the developed pressures were recorded (P(developed) = P(systolic) - P(diastolic)). Right ventricular failure was defined as a decrease in developed intracavitary pressure. Glycine hearts could be loaded with a significantly increased volume after 1 h (glycine: 53 +/- 13.7 ml vs. control: 32 +/- 11.7 ml; P = 0.015) and after 2 h (67 +/- 18.6 ml vs. 43 +/- 8.2 ml; P = 0.018). Maximal RV developed pressures were not significantly different between groups. Postischemic RV end-diastolic compliance was significantly higher in glycine-treated animals (P = 0.04). Glycine protects early postischemic RV compliance, but has no important influence on maximal developed pressures.

Animals↗
PubMed2006

Short moderate hypothermic circulatory arrest without any adjunctive cerebral protection for surgical repair of the ascending aorta extending into the proximal aortic arch: is it safe?

INTRODUCTION: We have been using only moderate hypothermic circulatory arrest (HCA) for patients with ascending aortic aneurysms extending into the proximal aortic arch if the distal anastomoses seem to be simple and easy. The aim of this study is to evaluate the early and midterm results of the use of moderate HCA without any adjunctive cerebral protection in such patients. METHODS: Between October 2000 and March 2005, 23 patients with an age range of 39 to 77 years (mean, 59.7 +/- 12.2 years) received surgical repair of the ascending aorta extending into the proximal aortic arch using HCA without any adjunctive cerebral protection. Mean circulatory arrest time was 7.5 +/- 2.0 minutes (range, 2-13 minutes), and mean core temperature at induction of the circulatory arrest was 26.7 +/- 1.4 degrees C (range, 24-30 degrees C). RESULTS: Operative mortality was 4.3% (1/23) due to unknown cause after successful extubation. Temporary neurological dysfunction was observed in only 1 patient (4.3%), and no persistent neurologic event was observed in any of the patients. One patient died 3 months after the operation due to a mediastinitis. No other cardiac or neurologic event was observed in the 21 surviving patients. CONCLUSION: Our results suggest that moderate HCA at 26 degrees C to 28 degrees C without any adjunctive cerebral protection within 10 minutes is safe in selected patients.

Adult↗
PubMed2005

Allopurinol/uricase and ibuprofen enhance engraftment of cardiomyocyte-enriched human embryonic stem cells and improve cardiac function following myocardial injury.

OBJECTIVE: A major limitation of stem cell transfer is early donor-cell death. Here, we seek to enhance myocardial repair following injury through transplantation of cardiomyocyte-enriched human embryonic stem cells (hESC) and recipient treatment with cytoprotective (allopurinol+uricase) and anti-inflammatory (ibuprofen) agents. METHODS: We injected 10(6) (15% hESC-derived cardiomyocytes) green fluorescent protein (GFP+) hESC in the infarcted area following left anterior descending artery (LAD)-ligation in SCID-beige mice. In Group I, 1.6 mg allopurinol and 0.2 mg of uricase were injected i.p. for 3 days prior to cell transplantation. In Group II, 0.35 mg/ml of ibuprofen were added to the drinking water before and after cell implantation. In Group III, the LAD was ligated and allopurinol/uricase was administered without cell treatment. In Group IV, ibuprofen was added to the drinking water and the LAD was ligated without additional cell treatment. In Group V, only cells were transplanted. Group VI involved infarcted controls and Group VII involved sham-operated mice (all groups: n=5). We evaluated heart function (ejection fraction (EF)) by MRI (4.7 T) 3 weeks later. The hearts were harvested for histology. RESULTS: Differentiated hESC formed clusters and expressed alpha-sarcomeric actin and Connexin 43. Cell treatment improved heart function, which was best in the ibuprofen- and allopurinol-treated groups (+cell transfer), compared to the infarcted controls [EF: Group I: 76.6+/-8.6%, Group II: 78.6+/-7.3%, Group III: 58.1+/-5.7%, Group IV: 53.9+/-5.2%, Group V: 57.7+/-7.5%, Group VI: 43.5+/-4.3%, and Group VII: 66.3+/-7.8%]. We did not observe tumors in any group. CONCLUSIONS: Allopurinol/uricase and ibuprofen enhance differentiated hESC-engraftment and myocardial restoration following transplantation into the injured heart.

Acute Disease↗
PubMed2005

Long-term physical activity and neurologic function after harvesting of the radial artery as T-graft or free graft in coronary revascularization.

BACKGROUND: Radial artery grafts in coronary revascularization are frequently used, either as a T-graft or as a free radial graft such as a saphenous venous graft. Besides the neurologic function of the hand after radial artery harvesting, which is questioned especially in the long-term perspective, no data on patients' lifestyle are available in this special cohort. Therefore we focused on both the patients' neurologic function as well as level of physical activity, along with their body mass index and smoking habits in this prospective, long-term study. METHODS: Two hundred eleven patients (187 males; 64 +/- 8 years; mean Canadian coronary scale, 2.4 +/- 0.7; ejection fraction, 59 +/- 15%) were enrolled and scheduled for elective radial artery harvesting in an open conventional technique. Follow-up of 26 +/- 5 months (range, 13 to 37 months) was performed by a direct telephone interview with patients, which was 100% complete. The majority of radial arteries were used in the T-graft technique (73.9%), 24.2% were used as a free graft, and 1.4% as a jump graft. RESULTS: One hundred sixty-five patients (78.2%) did not complain of any neurologic deficit at all. Numbness was distributed among the thumb (5.2%), the wrist (4.3%), and the incision site (3.3%). Hyposensitivity was predominantly at the wrist, followed by the thumb. Pain was distributed at the wrist (1.9%) and the thumb (1.5%). Aggravated sense of cold at the donor hand was evident in 11 patients (5.2%). No patient was compromised in their daily activities, such as piano playing or writing. Subjective well being improved in 147 patients (69.7%), was unchanged in 39 patients (18.5%), and was worse in 11 patients (5.3%) after radial artery harvesting. The mean Canadian coronary scale class improved significantly (1.3 +/- 0.6; p < 0.05). There were patients (44.5%) who performed no sports activity after the procedure and patients (11.8%) who performed sports every day of the week. There were patients (80.1%) who did not participate in heart sport groups, with only 27 patients (12.8%) participating in such heart sport groups once a week. One hundred seventy-one patients (81.0%) attended a cardiac rehabilitation program after the procedure. Body mass index did not change at all. There were patients (29%) who stopped smoking as of the procedure, whereas 10% of patients were active smokers 25 months after the procedure. CONCLUSIONS: Radial artery harvesting is associated with a minor number of neurologic complications such as numbness and hyposensitivity after a conventional pedicled harvesting technique without any compromise on patients' daily activities. Further emphasis has to be taken in the promotion of lifestyle changes after coronary revascularization. About half of the patients did not perform any regular physical activity 2 years after surgery; mean body mass index did not change; and nearly 10% continued to smoke.

Body Mass Index↗
PubMed2005

First clinical results with a 30 degrees end-to-side coronary anastomosis coupler.

OBJECTIVE: The purpose of this study is to evaluate the safety and efficacy of a novel 30 degrees end-to-side coronary anastomotic coupler (Converge Medical, Inc., Sunnyvale, CA) that facilitates a non-penetrating, sutureless vein graft to coronary artery anastomosis. MATERIAL AND METHODS: The Coupler utilizes a set of concentric mating frames approximating adjacent vessel tissue allowing for biological healing of the anastomosis. The frames are manufactured from Nitinol, a nickel titanium super-elastic metal alloy. The Nitinol frames attach the bypass graft to the coronary artery in a 30 degrees end-to-side configuration. Between November 2002 and March 2003 a total of 46 patients (44 male) with a mean age of 63.6+/-7.5 years were admitted for coronary artery revascularization and included in the study. The mean LVEF was 60.6+/-12.4%. RESULTS: Thirty-three patients were successfully treated with the Coupler. Nine patients did not meet the intraoperative inclusion criteria, and were excluded from the study due to small (<or=2.0mm) or severely calcified coronary vessels, or small vein grafts. Hemostasis could not be achieved with the Coupler in 3 patients, and in one patient the graft flow measured intraoperative was low. In these instances the Coupler was removed and the anastomosis was sutured without complication. Average mean flow rate using transit time method through the Coupler attached bypasses was 54+/-26ml/min. In a control angiography 2 months after surgery, 29 (96.7%) of the 30 connector grafts were patent. One stenosis of 50% occurred on the site of a connector anastomosis. Angiographic patency assessments for 81 hand sewn grafts revealed 73 (90.1%) patent grafts. CONCLUSION: Initial results indicate that the Converge Coupler can be used to create a safe and effective 30 degrees vein graft to coronary artery anastomosis under suitable conditions.

Aged↗
PubMed2005

Severe right heart failure after heart transplantation. A single-center experience.

We reviewed our heart transplantation recipient population, using hard criteria defining severe right heart failure (RHF), and analyzed possible risk factors for outcome after RHF. Between 1983 and 1998 621 cardiac transplantations were performed at our institution. RHF was defined by the necessity to implant an assist device or echocardiographically confirmed right ventricular ballooning with concomitant end organ failure. RHF patients were compared with a matched control group. Thirty-five patients (5.9%) with severe RHF after transplantation fulfilled inclusion criteria. Of these, 32 patients died, while none of the control patients died (P < 0.001). Increased preoperative pulmonary capillary wedge (P = 0.005) and mean pulmonary artery pressure (P = 0.006) were identified as significant risk factors for severe RHF. Severe RHF as defined in our study is irreversible in almost every case without differences among therapeutical concepts. Hence, improvement of postoperative outcome necessitates avoidance or aggressive therapy of possible risk factors.

Adult↗
PubMed2004

Magnetic Vascular Port in minimally invasive direct coronary artery bypass grafting.

BACKGROUND: Minimally invasive direct coronary artery bypass grafting (MIDCAB) is a well-established operative procedure. However, it is technically demanding and is therefore somewhat underused. We evaluated the clinical and angiographic outcome of patients undergoing a MIDCAB procedure with the Ventrica Magnetic Vascular Port (MVP) system. METHODS AND RESULTS: A Ventrica MVP system was used in 10 of 11 selected MIDCAB patients. The system consists of 6 magnetic clips, with 3 clips forming a set. One magnetic clip set is positioned at the arteriotomy of the target artery and of the bypass graft using a preloaded delivery system. These ports then form an anastomosis by magnetic coupling. The mean age of the 10 patients (6 male) was 60.3+/-11.0 years. Three patients had an angiogram at the time of discharge and 8 returned for a 6-month angiogram. The total procedure time was 128.2+/-12.2 minutes. The mean anastomotic time was 199 seconds. The mean ischemic time during the anastomosis was 146+/-146 seconds. There were no in-hospital complications and no device-related adverse events. All 3 predischarge and all 8 6-month angiograms showed patent anastomoses. CONCLUSIONS: The magnetic vascular port facilitates the MIDCAB procedure significantly and reduces the ischemic time during the anastomosis. This minimally invasive procedure has the potential to be an alternative to percutaneous transluminal coronary angioplasty and stenting in proximal left anterior descending (LAD) stenosis. It may expand the acceptance of hybrid procedures in which a left internal mammary artery (LIMA)-to-LAD graft optimally supplies the anterior wall and the septum while the circumflex and right coronary artery may be treated interventionally.

Aged↗
PubMed2004

Impact of multivessel coronary artery disease on outcome after isolated minimally invasive bypass grafting of the left anterior descending artery.

BACKGROUND: The outcome in patients treated surgically for coronary artery disease is known to be influenced by the extent of the disease. Whether this factor also has an effect in patients undergoing isolated minimally invasive revascularization of the left anterior descending (LAD) artery using the internal thoracic artery (ITA) (MIDCAB) has not been looked at. Thus, this study sought to evaluate the impact of multivessel disease (MVD) on midterm outcome after MIDCAB. METHODS: From 1996 to 1999, 411 patients received a MIDCAB at our institution and were now followed up. Isolated disease of the LAD (SVD -single vessel disease) was presented in 262 patients (63.7%) and 149 patients (36.3%) had MVD at the time of operation. The reasons for apparent incomplete revascularization in patients with MVD were very small target vessels (< 1.0-mm diameter), stenoses of less than 50%, distal localization of the stenoses, long-term patency after angioplasty, or an extensive risk for sternotomy and(or) cardiopulmonary bypass. The midterm outcome was evaluated by questionnaires sent to the patients and their physicians. RESULTS: The mean follow-up was 29.4 +/- 11.1 months. The incidence of myocardial infarction was significantly higher in MVD as compared to SVD patients (8.1% vs 1.9%, p = 0.04). Patients with MVD had significantly more subsequent percutaneous transluminal coronary angioplasty (10.7% vs 5.3%, p = 0.049) and a similar number of repeat surgical revascularizations as compared to SVD patients. Patients with MVD had a significantly higher total 3-year mortality as compared to SVD patients by Kaplan-Meier estimate (8.7% vs 3.1%, relative risk [RR] = 2.56, p = 0.011). The 3-year cardiac mortality was significantly higher in patients with MVD as compared to SVD (4.0% vs 0.4%, RR = 9.48, p = 0.0054). After adjustment of baseline characteristics by Cox regression analysis, the 3-year risk of cardiac death was significantly higher in the MVD groups (RR = 2.2, confidence interval [CI] 95%: 1.8 to 4.65, p = 0.029). CONCLUSIONS: Patients with isolated disease of the LAD appear to benefit from ITA grafting in the form of a MIDCAB procedure. Here, it should be an approach of choice. The results show that MVD is an independent risk factor for outcome in patients undergoing a MIDCAB procedure. Nevertheless, the midterm morbidity and mortality in MVD patients after a MIDCAB procedure where the LAD is the only target vessel for interventional or surgical treatment is acceptable despite a higher morbidity than in SVD patients.

Aged↗
PubMed2004

Impact of diabetes on outcome following isolated minimally invasive bypass grafting of the left anterior descending artery.

BACKGROUND: The outcome in patients treated by conventional coronary artery bypass grafting (CABG) for coronary artery disease is negatively influenced by the presence of diabetes. The relative effect of diabetes in patients undergoing isolated minimally invasive revascularization of the left anterior descending artery (LAD) using the internal thoracic artery (ITA) has as yet not specifically been looked at. Thus, this study sought to evaluate the impact of diabetes on mid-term outcome following minimally invasive coronary artery bypass grafting (MIDCAB). METHODS: From 1996 to 1999, 411 patients received a MIDCAB procedure at our institution and were now followed up. In this study population there were 63 diabetic patients (15.3%) and 348 nondiabetic patients (84.7%). Isolated proximal stenoses or an occlusion of the LAD were present in 262 patients (63.7%), whereas 149 (36.3%) had multi-vessel disease (MVD) at the time of the MIDCAB procedure. The clinical outcome was evaluated by questionnaires sent to the patients and their physicians. RESULTS: The mean follow-up was 29.4 +/- 11.1 months. The incidence of myocardial infarction was significantly higher in diabetics as compared to nondiabetics (9.5% vs 3.2%, p = 0.034). Diabetics and nondiabetics had similar rates of subsequent revascularization procedures during follow-up. Cumulative total survival of diabetic and nondiabetic patients was not statistically different. The 3-year cardiac mortality was however significantly higher in diabetic than in nondiabetic patients if MVD was initially present (Kaplan-Meier estimate: 10.7% vs 2.5%, relative risk [RR] = 5.5, p = 0.017 by log-rank test). The 3-year cardiac mortality in diabetic and nondiabetic patients with isolated disease of the LAD (single vessel disease [SVD]) was not significantly different. After adjustment of baseline characteristics by Cox regression analysis the 3-year risk of cardiac death was significantly higher in the diabetic group (RR = 1.82, CI 95%:1.2 to 3.3, p = 0.045). CONCLUSIONS: The results support diabetes to be an independent risk factor for outcome in patients with MVD undergoing a MIDCAB procedure in analogy to those undergoing CABG procedures. Diabetics with isolated disease of the LAD, however, benefit out of proportion from this treatment modality.

Aged↗
PubMed2003

Magnetic vascular coupling for distal anastomosis in coronary artery bypass grafting: a multicenter trial.

OBJECTIVE: The hand-sewn anastomosis is the "gold standard" for performing coronary artery bypass grafts. However, performing a hand-sewn anastomosis is more demanding and time-consuming when used in less invasive approaches such as small access, totally endoscopic or beating heart surgery. In conjunction with attempts to reduce the surgical trauma of coronary artery bypass grafts by using these less invasive approaches, alternative methods for constructing distal anastomoses should be explored. These data report on predischarge angiographic findings and 30-day clinical follow up of patients who have received a new distal anastomotic device. METHODS: In a multicenter trial, 32 patients (mean age: 65 +/- 9 years; 85% men) requiring multivessel coronary artery bypass surgery had 1 of the anastomoses performed using a novel anastomotic technology. The Magnetic Vascular Positioner System was used in 1 of the bypass grafts and the other bypasses were completed by conventional hand-sewn technique. The Magnetic Vascular Positioner System consists of 4 magnetic, gold-plated implants and 2 delivery devices that facilitate the creation of a functional end-to-side anastomosis. A predischarge angiogram was performed to evaluate graft patency. RESULTS: There were no device-related major adverse events. The application of the Magnetic Vascular Positioner device was successful in 32 of 41 cases (78%). Nine patients were intended for treatment but did not receive the Magnetic Vascular Positioner System. In 5 of the cases the coronary artery was too small; 1 case had a posterior wall plaque in the target artery; and 3 patients had a nonhemostatic anastomosis after coupling of the port and were subsequently converted to hand-sewn anastomoses. The median total Magnetic Vascular Positioner anastomotic time was 137 seconds with a range from 65 to 370 seconds. Overall patency rate of the Magnetic Vascular Positioner anastomosis was 93.5% versus 91.7% (P = not significant) in hand-sewn grafts. One patient (3.1%) died due to low cardiac output but had patent grafts at autopsy. One myocardial infarction (3.1%) occurred the day after a percutaneous transluminal coronary angioplasty of a hand-sewn graft. One prolonged mechanical ventilation (3.1%) was required because of pneumonia and adult respiratory distress syndrome. CONCLUSIONS: Magnetic vascular coupling in coronary surgery is safe and effective and has acceptable early patency rates. This new technique may facilitate beating heart and minimally invasive coronary artery bypass grafts.

Adult↗
PubMed2002

Combined correction of an adult scimitar syndrome and coronary artery bypass grafting.

Combined scimitar syndrome and coronary artery disease is a rare combination of congenital and acquired cardiac disease in adults. Hence, no guidelines for surgical correction are available. We report on the case of a 60-year-old man with coronary artery disease and scimitar syndrome. The patient underwent arterial coronary revascularization and simultaneous correction of the scimitar syndrome utilizing a new surgical approach with a modified pericardium-baffle reconstruction of the anomalous right pulmonary vein.

Combined Modality Therapy↗