Biomedical subjects
Ernst Wolner
Publications and source records attributed to Ernst Wolner.
Reconstitution of blood supply of the denuded bronchial stump.
BACKGROUND: Our aim was to study the process of microcirculatory reconstitution in the bronchial stump after pneumonectomy. METHODS: Eighteen juvenile pigs (median weight 40.6 kg) were randomly assigned to three groups. In all animals left pneumonectomy was performed and the stapled bronchial stump (median length 3.8 cm) carefully denuded. Group I animals received coverage of the stump by intercostal flap. In group II, the stump was covered with TachoComb, an impermeable hemostatic fleece; and group III served as a control without any coverage of the stump. Animals were sacrificed at day 14 after surgery. Vascular density was evaluated in serial histologic sections at multiple levels stained with CD-31 antibody. One-way analysis of variance and the Wilcoxon test were used for data analysis. RESULTS: At autopsy, stumps of group III animals were totally covered by adjacent mediastinal structures. In group I, intercostal flaps were viable and completely healed to the bronchial stumps. There were no signs of infection or stump insufficiency in these groups. In all group II animals, empyema developed, and stumps were found necrotic at macroscopic and histologic evaluation. Statistical analysis revealed significantly lower vascular density of mature vessels in the area of the bronchial stump in group II compared with both other groups. CONCLUSIONS: Reconstitution of microcirculation of the denuded bronchial stump after pneumonectomy takes place in a centripetal way from adjacent viable tissue. Hence, the purpose of covering the bronchial stump is the improvement of blood supply rather than mechanical reinforcement.
Physiology of continuous blood flow in recipients of rotary cardiac assist devices.
The beating heart and the resultant pulse wave have been a symbol of life for centuries. The development history of roller pumps for cardiopulmonary bypass shows that the human body tolerates non-pulsatile blood flow, at least for short-term support. Over the last few years, many types of rotary blood pumps have been developed for clinical use in patients requiring mid- to long-term support. Although early clinical experiences in patients with long-term support have been promising, the matter of whether pulsatile flow is needed or not remains controversial. Therefore, this review summarizes the observed clinical consequences of continuous blood flow in patients supported by rotary blood pumps and relates these consequences to underlying experimental studies.
Surgical ablation of atrial fibrillation with off-pump, epicardial, high-intensity focused ultrasound: results of a multicenter trial.
BACKGROUND: A simplified alternative to the Cox maze procedure to treat atrial fibrillation with epicardial high-intensity focused ultrasound was evaluated clinically, and the initial clinical results were assessed at the 6-month follow-up visit. METHODS: From September 2002 through February 2004, 103 patients were prospectively enrolled in a multicenter study. Atrial fibrillation duration ranged from 6 to 240 months (mean, 44 months) and was permanent in 76 (74%) patients, paroxysmal in 22 (21%) patients, and persistent in 5 (5%) patients. All patients had concomitant operations, and ablation was performed epicardially on the beating heart before the concomitant procedure. The device automatically created a circumferential left atrial ablation around the pulmonary veins in an average of 10 minutes, and an additional mitral line was created epicardially in 35 (34%) patients with a handheld device by using the same technology. RESULTS: No complications or deaths were device or procedure related. There were 4 (3.8%) early deaths and 2 late extracardiac deaths. The 6-month follow-up was complete in all survivors. At the 6-month visit, freedom from atrial fibrillation was 85% in the entire study group (80% in patients with permanent atrial fibrillation, 88% in the 35 patients who had the additional mitral line, and 100% in patients with paroxysmal atrial fibrillation). A pacemaker was implanted in 8 patients. Only the duration and type of atrial fibrillation significantly increased the risk of recurrence. CONCLUSION: Epicardial, off-pump, beating-heart ablation with acoustic energy is safe and cures 80% of patients with permanent atrial fibrillation associated with long-standing structural heart disease.
An alternative approach in treating an aortic arch aneurysm with an anatomic variant by supraaortic reconstruction and stent-graft placement.
We report the case of a 78-year-old man who presented with an aortic arch aneurysm that involved the origin of the left carotid artery and extended up to the origin of the brachiocephalic trunk. The left vertebral artery originated separately from the arch. The patient was treated by a reversed bifurcated prosthesis from the ascending aorta to the brachiocephalic trunk as well as to the left common carotid artery, and a simultaneous left-sided vertebral-to-carotid artery transposition was also performed. Metachronously, the patient later underwent successful endovascular stent-graft placement into the entire aortic arch.
Is the transpulmonary pressure gradient a predictor for mortality after orthotopic cardiac transplantation?
Elevated pulmonary vascular resistance (PVR) is a well-known risk factor for right ventricular failure after orthotopic cardiac transplantation. The influence of preoperative transpulmonary pressure gradient (TPG) and PVR on post-transplant 30 days mortality was evaluated. To analyze the response of PVR and TPG to cardiac transplantation, we analyzed 718 adult patients undergoing primary cardiac transplantation. Indications for operation were: 35.2% ischemic cardiomyopathy (ICM), 61.2% idiopathic dilated cardiomyopathy (DCM), and 3.3% other diagnosis (e.g. hypertrophic cardiomyopathy). The mean age (51.9) and the mean ischemic time (169.7 min) were comparable between 30 days survivors and nonsurvivors. Student's t-tests and chi-square analysis were used to compare data from 30-day survivors and nonsurvivors. Statistical significance was defined as P < 0.05. Fisher's exact test and multiple logistic regression analysis was performed to evaluate the relationship between hemodynamic parameters and outcome after transplantation. Primary end-point was 30 days mortality and secondary end-point long-term survival of patient groups with different TPG and PVR values. In survivors the mean TPG was 10.3 +/- 5.1 (mean +/- SD) vs. 13 +/- 6.6 in patients who died after transplantation (P = 0.0012). The PVR was 2.6 +/- 1.4 vs. 3.5 +/- 2.2 (P = 0.0012). In multivariate logistic regression, the parameters TPG and PVR exhibit a significant influence between survivors and nonsurvivors after cardiac transplantation within 30 days (TPG: P = 0.0012; PVR: P = 0.0012). The mortality rates in patients with TPG > 11 mmHg and PVR < 2.8 Wood units or TPG < 11 mmHg and PVR > 2.8 Wood units were comparable to those with TPG < 11 mmHg and PVR < 2.8 mmHg. The TPG is an important predictor in nonrejection-related early mortality after orthotopic cardiac transplantation. The determination of TPG in combination with PVR is a more reliable predictor of early post-transplant survival than PVR alone.
In vivo measurement of levofloxacin penetration into lung tissue after cardiac surgery.
Nosocomial pneumonia is a severe complication after cardiac surgery (CS). Levofloxacin, a fluoroquinolone, qualifies for the therapy of postoperative pneumonia. However, penetration properties of levofloxacin into the lung tissue could be substantially affected by CS: atelectasis, low cardiac output after CS, high volume loads, and inflammatory capillary leak potentially influence drug distribution. The aim of our study was to gain information on interstitial antibiotic concentrations in lung tissue in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass. Therefore, six patients undergoing elective CS participated in this prospective study. A dose of 500 mg of levofloxacin was administered intravenously in addition to standard antibiotic prophylaxis immediately after the end of surgery. Time versus concentration profiles of levofloxacin in the interstitial lung tissue and plasma were determined. A microdialysis technique was used for lung interstitial concentration measurements. The microdialysis procedure was well tolerated in all patients and no adverse events were observed. The median area under the concentration curve (AUC) of levofloxacin in interstitial lung fluid was 18.6 microg.h/ml (range, 10.1 to 33.6). The median AUC for tissue (AUC(tissue)) of unbound levofloxacin/AUC(total) in plasma was 0.6 (range, 0.4 to 0.9). The median unbound AUC(tissue)/MIC was 2.4 (range, 1.3 to 4.2) for Pseudomonas aeruginosa. Our study demonstrated the feasibility and safety of microdialysis in human lung tissue in vivo after CS. The unbound AUC/MIC ratio revealed that levofloxacin used in the described manner was borderline sufficient for the treatment of nosocomial pneumonia caused by Klebsiella pneumoniae and insufficient for the treatment of pneumonia caused by Pseudomonas aeruginosa, because the breakpoint of 30 to 40 for AUC/MIC could not be reached by the conventionally used dosage schema in our post-CS setting. Penetration was lower than in previous reports.
The decellularized porcine heart valve matrix in tissue engineering: platelet adhesion and activation.
An approach in tissue engineering of heart valves is the use of decellularized xenogeneic matrices to avoid immune response after implantation. The decellularization process must preserve the structural components of the extracellular matrix to provide a biomechanically stable scaffold. However, it is known that in vascular lesions platelet adhesion to extracellular matrix components occurs and platelet activation is induced. In the present study we examined the effects of a decellularized porcine heart valve matrix on thrombocyte activation and the influence of re-endothelialisation in vitro. Porcine pulmonary conduits were decellularized using Triton X-100, Na-deoxycholate and Igepal CA-630 followed by a ribonuclease digestion. Cryostat sections of decellularized heart valves with and without seeding with human umbilical vein endothelial cells (HUVEC) were incubated with platelet rich plasma. Samples were either stained with fluorescent antibodies for CD41 and PAC-I (recognizing the activated fibrinogen receptor) or fixed with glutaraldehyde. Thereafter, the samples were processed for laser scanning microscopy (LSM) or scanning electron microscopy (SEM). Examination by LSM showed numerous platelets with co-localized staining for CD41 and PAC-1 on the nonseeded decellularized heart valve matrix whereas after seeding with endothelial cells no platelet activation was detected. SEM revealed platelet adhesion and aggregate formation only on the surface of the non-seeded or partially denuded matrix specimens. We show in this study that the decellularized porcine matrix acts as a platelet-activating surface. Seeding with endothelial cells effectively abolishes the platelet adhesion and activation and therefore is necessary to eliminate thrombogenicity in tissue engineered heart valves.
Improved outcome in thoracoabdominal aortic aneurysm repair: the role of cerebrospinal fluid drainage.
INTRODUCTION: To evaluate the protective effect and the optimum duration of cerebrospinal fluid drainage (CSFD) during and after thoracoabdominal aortic aneurysm (TAAA) repair. METHODS: From April 2001 to October 2003, we retrospectively compared 17 (n = 17) consecutive patients who have been electively operated on by Martin Grabenwoger for left heart bypass and selective perfusion of the visceral and renal organs. RESULTS: The first 7 patients had CSFD for 72 hours; the duration of CSFD was increased to 100 hours in the remaining 10 patients. Median drained cerebrospinal fluid (CSF) volume was 680 milliliters in the 72-hour group versus 1441 milliliters in the 100-hour group. A characteristic increase in CSF volume was noted between POD No. 2 and POD No. 4 indicating persistent spinal cord edema. Univariate and multivariate analysis demonstrated that CSFD for 100 hours is a significant predictor for decreased incidence of late onset paraplegia (p < 0.001). The overall incidence of postoperative neurological deficit was 17.6% (3 of 17). There was one patient (6%) who developed permanent paraplegia and two patients (12%) with transient paraplegia. These patients sustained late-onset paraplegia 72 hours after surgery for removal of a CSFD device. Complete motor function could be restored after re-insertion of a CSFD device. In one patient, permanent paraplegia was evident after awakening from anesthesia. Because of technical difficulties, only two intercostal arteries could be re-implanted, which was obviously not sufficient to restore spinal cord perfusion. In contrast, no neurological deficit occurred in patients in whom a CSFD instrument was left for 100 hours. CONCLUSION: The extended duration of CSFD may lower the risk of late-onset paraplegia and could improve outcome in patients undergoing thoracoabdominal aortic surgery.
Total endoscopic CABG using robotics on beating heart.
BACKGROUND: The implementation of a total endoscopic coronary surgery on the beating heart with the aid of the Da Vinci surgical system (Intuitive, Sunnyvale, CA) requires a stepwise learning process. After cadaveric training and clinical start of the program in November 2002, we gained experience with arrested heart procedures starting in May 2003. In November 2003, we moved to beating heart surgery. METHODS: From November 2003 to January 2005, 14 patients with coronary artery disease (mean age of 62 +/- 5 years, female to male ratio 2:12) were operated with the intention to perform a beating heart TECAB (totally endoscopic coronary artery bypass grafting) procedure. RESULTS: Total conversion rate was 35% (5/14), due to pleural adhesions in 2 patients, injury of the lung during port placement, inability to occlude the LAD with saddle loops, atherosclerotic diseased mammary artery in 1 patient each. Mean operating time was 298 +/- 110 minutes with a steady decline throughout the study period (first 5 patients: 342 +/- 61 minutes, patients 6 to 9: 337 +/- 87 minutes, last 4 patients: 290 +/- 53 minutes), resulting in a 60 minute shorter operating time. Mean ICU stay was 1.3 days and hospital stay lasted on average 8.4 +/- 2.8 days. CONCLUSION: Total endoscopic bypass surgery on the beating heart with the Da Vinci surgical system can be safely implemented in clinical use. The learning curve results in a constantly decreasing procedure time due to a more effective table team-console surgeon-robotic system interaction and a moderate conversion rate.
Soluble ST2 protein in cardiac surgery: a possible negative feedback loop to prevent uncontrolled inflammatory reactions.
BACKGROUND: Recent reports have demonstrated that cardiopulmonary bypass (CBP) utilization leads to a TH2 cytokine bias in patients undergoing coronary artery bypass grafting (CABG) operation. The relation of soluble ST2 and secretion of IL-10, markers of TH2 T-cell activation, and IL-13 in relation to immunoglobulin isotope production is not known in patients undergoing On- versus Off-pump (CABG) procedure. METHODS: 30 patients were prospectively included in the study (On- vs Off-pump CABG, each n = 15). Serum samples were obtained prior to, and 30 min, 60 min and 24hrs after operation. ELISA was utilized to detect sST2 and IL-10, IL-13 and immunoglobulin isotype production. RESULTS: In both cohorts we could demonstrate a significant rise of ST2 24 hours after the CABG procedure. In the On-pump group ST2 levels (pg/ml) before the operation, at 30 and 60 minutes and after 24 hours were 115.3 +/- 25, 71.2 +/- 15, 114.1 +/- 26 and 4231.9 +/- 520, respectively. In the Off-pump group they were 200.3 +/- 109, 91.2 +/- 20, 137 +/- 29 and 4144.9 +/- 488 (both, p < 0.0001, p < 0.0001, respectively). IL-10 (pg/ml) levels rose from preoperative values of 6.2 +/- 1.6 in the On-pump group and 7.91 +/- 1.8 in the Off-pump group to 33.14 +/- 8.7 and 13.72 +/- 3 after 60 minutes (p 0.0189, p 0.0397, respectively). IL-13 levels and immunoglobulin production did not change significantly within the study period irrespective of the operation procedure used. CONCLUSION: In conclusion, our results demonstrate that sST2 and IL-10, markers of TH2 cytokine producing cells, are increased in CABG operation, irrespective of the procedure selected, and settles a longstanding controversy concerning the shift from Th1 to Th2 cells.
Thrombophilia associated with anti-CD154 monoclonal antibody treatment and its prophylaxis in nonhuman primates.
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Comparison of combined prophylaxis of cytomegalovirus hyperimmune globulin plus ganciclovir versus cytomegalovirus hyperimmune globulin alone in high-risk heart transplant recipients.
BACKGROUND: Seronegative heart transplant recipients who receive an allograft from seropositive donors have a higher risk of developing cytomegalovirus (CMV) disease and cardiac allograft vasculopathy (CAV) and dysfunction. Neither CMV-specific hyperimmune globulin nor ganciclovir as sole CMV prophylaxis is sufficient to prevent CMV disease in high-risk patients. We retrospectively evaluated the efficacy of CMV-hyperimmune globulin with and without ganciclovir in 207 D+/R- heart transplant recipients. METHODS: The study population was divided into two groups: Group A was composed of 96 patients who received CMV hyperimmune globulin as sole CMV prophylaxis, and group B was composed of 111 patients who received combined CMV prophylaxis. All recipients were subjected to quadruple cytolytic immunosuppression. Primary and secondary end points included prevention of CMV-associated death, CMV disease and productive infection, CAV, and overall infection. RESULTS: There was no difference in overall survival between the two groups. Four patients in the group A died of CMV sepsis, whereas no CMV-associated death was observed in group B (P =0.0326). The actuarial incidence of CMV disease was significantly lower in patients who received double CMV prophylaxis (32.29 vs. 11.71, P =0.0003). Although no difference was observed with regard to productive CMV infection (53.12 vs. 65.77, P =not significant), CAV and overall infection rates were significantly higher in the first group (7.29 vs. 0.9, P =0.0157 and 70.83 vs. 62.16, P =0.03, respectively). CONCLUSIONS: Double CMV prophylaxis consisting of CMV hyperimmune globulin and ganciclovir is able to abolish CMV death and prevent CMV disease in high-risk heart transplant recipients. Therefore, the use of a combination regimen is recommended for seronegative recipients with seropositive donors.
Increased levels of soluble ST2 protein and IgG1 production in patients with sepsis and trauma.
OBJECTIVE: T1/ST2, a member of the interleukin (IL)-1 receptor superfamily, is predominantly expressed on type-2 T helper (Th2) cells but not Th1 cells, and plays a role in cell proliferation and Th2 immune response. The relation of soluble ST2, Th1-Th2 cytokine profile, and immunoglobulin (Ig) production in sepsis and trauma patients is not well known. DESIGN AND SETTING: Case-control study at a university hospital intensive care unit. PATIENTS: Fifteen patients recruited within 24-48 h of diagnosis of sepsis, 13 trauma patients recruited within 24 h after admission to the ICU, 11 patients who underwent abdominal surgery, and 15 healthy volunteers served as control. MEASUREMENTS AND RESULTS: ELISA was utilized to detect serum soluble ST2, IL-2, IFN-gamma, IL-10, and Ig production. Serum levels of soluble ST2 were significantly increased in septic patients (8420+/-2169 pg/ml) as compared with trauma (2936+/-826 pg/ml), abdominal surgery (1423+/-373 pg/ml), and healthy controls (316+/-72 pg/ml; p<0.001, respectively). These results were accompanied by an increase of IgG1 and IgG2 production, and decrease of IL-2 and IFN-gamma synthesis in septic patients. IL-10 was significantly increased in both septic and trauma patients. CONCLUSIONS: Our results demonstrate that soluble ST2, a marker for Th2 cytokine producing cells, is increased in sepsis and trauma patients, and they provide further evidence for a shift from Th1- to Th2-biased cells.
Sealing of the mediastinum with a local hemostyptic agent reduces chest tube duration after complete mediastinal lymph node dissection for stage I and II non-small cell lung carcinoma.
BACKGROUND: We assessed the impact of coverage of the mediastinum with a local hemostyptic agent as well as the impact of perioperative thromboembolic prophylaxis on cumulative chest drain volume and on the duration of chest tubes after surgical resection with complete mediastinal lymph node dissection for stage I or II non-small cell lung cancer. METHODS: In a prospective, randomized two-by-two factorial design, 80 patients with clinical stage I or II non-small cell lung cancer were allocated to one of two surgical therapy arms (TachoComb or conventional surgical hemostasis) and one of two anticoagulation arms (enoxaparin 4,000 IU or dalteparin 5,000 IU). Primary end point was cumulative chest drain volume; secondary end point was duration of chest tubes. Additionally clinical data were obtained. RESULTS: Comparison of the surgical arms revealed significantly lower cumulative chest drain volumes and thereby an earlier chest tube removal in the TachoComb group (p = 0.045). With regard to thromboembolic prophylaxis, a significantly earlier chest tube removal was found for patients treated with dalteparin (p = 0.039). Analysis of the interaction of surgical and anticoagulation treatment revealed the combined use of TachoComb and dalteparin was superior to other combinations (cumulative chest drain volumes 498 +/- 67 mL versus 1,000 +/- 88 mL, 924 +/- 87 mL, and 895 +/- 118 mL; p = 0.008; mean duration of chest tubes 1.78 +/- 0.15 days versus 2.96 +/- 0.21 days, 2.93 +/- 0.17 days, and 3.06 +/- 0.27 days; p = 0.019). CONCLUSIONS: The combined use of a local hemostyptic agent and dalteparin seems superior as compared with other regimens of hemostasis and thromboembolic prophylaxis in patients undergoing surgical resection and complete mediastinal lymph node dissection for stage I and II non-small cell lung cancer with regard to cumulative chest drain volume as well as duration of chest tubes.
Lung wedge resection improves outcome in stage I primary spontaneous pneumothorax.
BACKGROUND: To evaluate the role of apical lung wedge resection in patients with recurrent primary spontaneous pneumothorax with no endoscopic abnormalities at surgery as compared with simple apical pleurectomy. METHODS: We performed a retrospective analysis on 126 consecutive video-assisted thoracoscopic surgery (VATS) procedures in 113 patients treated for stage I recurrent PSP between January 1994 and December 2001. Two surgical strategies were applied: simple apical pleurectomy (57 procedures, 45.2%: group A) and apical pleurectomy together with an apical lung wedge resection (69 procedures, 54.8%: group B). RESULTS: Mean duration of chest tubes was 1.4 days (range, 1 to 7), mean hospital stay was 2.4 days. Three patients (2.4%) required redo VATS, 2 in group A (3.5%) for persistent air leak and 1 (1.4%) in group B for apical hematothorax. Mean follow-up was 38.7 months. Overall recurrence rate was 3.2%. Four patients in group A (7%) experienced recurrent ipsilateral pneumothoraces 4 to 73 weeks (mean, 30.2) after surgery. No recurrences were observed in group B (p = 0.009). CONCLUSIONS: In this selected group of patients without endoscopical abnormalities, VATS offers low recurrence rates. However, these data suggest that apical pleurectomy should be accompanied by apical lung wedge resection even for this favorable category of patients.
Triangular plication of the anterior mitral leaflet: a new operative technique.
This study describes the technique of triangular plication in patients with mitral valve incompetence that is due to segmental anterior leaflet prolapse. A nonabsorbable suture plicates the prolapsed leaflet area towards the ventricular aspect in a triangular fashion by decreasing the suture width towards the leaflet base. Because no leaflet tissue is resected, this technique allows for the intraoperative correction of an imperfect plication. Triangular plication was successful in all except one patient. In this patient, a failed repair was corrected with mitral valve replacement. Freedom from mitral valve incompetence of more than grade 0-I was 100% at 12 months and 86% at 36 months postoperatively.
Neurocognitive deficit following coronary artery bypass grafting: a prospective study of surgical patients and nonsurgical controls.
BACKGROUND: To objectively measure long-term neurocognitive deficit in patients undergoing coronary artery bypass grafting and compare the findings with nonsurgical controls. METHODS: We prospectively measured neurocognitive function in patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass (n = 104; mean age 64.1 years old; EuroSCORE 2.7 [means]). A cohort of age- and sex-matched patients (n = 80; mean age 63.4 years old) served as nonsurgical controls. After CABG, neurocognitive function was serially reevaluated at 7-day (n = 104), 4-month (n = 100), and 3-year follow-up (n = 88). Neurocognitive function was objectively measured by means of cognitive P300 evoked potentials. Additionally, standard psychometric tests were performed (Trailmaking Test A, Mini Mental State Examination). RESULTS: As compared to preoperative measures (364 +/- 36 ms), cognitive P300 evoked potentials were prolonged (=impaired) at 7-day (381 +/- 36 ms; p = 0.001), 4-month (378 +/- 31 ms; p = 0.08), and 3-year follow-up (379 +/- 35 ms; p = 0.002), respectively. Trailmaking Test A was abnormal, as compared to preoperative, at 3-year follow-up (p < 0.001). Before the operation, surgical patients were fully comparable in P300 measures to nonsurgical controls (363 +/- 32 ms; p = 0.362). Most importantly, throughout the entire postoperative follow-up cognitive measures in surgical patients were prolonged (=impaired) as compared with controls (7-day p = 0.001; 4-month p = 0.002 and 3-year p = 0.003, respectively). In stepwise multivariate regression analysis, neurocognitive deficit at 4-month follow-up (p < 0.001), age (p = 0.012), and persistent atrial fibrillation (p = 0.024) were predictive for long-term neurocognitive deficit at 3-year follow-up. CONCLUSIONS: As shown by means of objective measures, and in comparison to nonsurgical controls, coronary artery bypass grafting with cardiopulmonary bypass grafting causes long-term neurocognitive deficit.