U. Tochtermann

Does the completeness of revascularization affect early survival after coronary artery bypass grafting in elderly patients

OBJECTIVE Usefulness and risks of incomplete versus complete revascularization are still matters of ongoing discussions. Because an increasing number of elderly patients are undergoing coronary artery bypass grafting (CABG), the question arises whether a less extensive surgical approach is more prudent than complete revascularization. METHODS Of 6531 patients undergoing isolated CABG, 859 were 75 and older at the time of operation. Mean age of the 859 patients was 77+/-2.7 years (median: 76 years); 65% were men. Follow-up enquiry by questionnaire was performed at the 180th postoperative day with a completeness of 95.6%. Assessment of the impact of incomplete revascularization utilized both multivariable analysis and propensity score matching to account for selection factors. RESULTS Incomplete revascularization was performed in 133 patients (16%). The most common reasons for incomplete revascularization were small vessels (55%) and massive calcification (32%). Mortality until 180 days after CABG was higher (n=32; 24%) after incomplete than after complete revascularization (n=105; 15%; P=0.005). By logistic multivariable regression, incomplete revascularization was identified as an independent risk factor for death (Odds ratio, 1.8; P=0.015). By time-related analysis, incomplete revascularization predominantly affected the early period after CABG (P=0.001). Aortic cross clamping time was only slightly shorter for the group with incomplete (59+/-27 min (median: 55 min) vs. 63+/-26 min (median: 58 min); P=0.1). CONCLUSIONS Incomplete revascularization increases the early risk of death after CABG in patients aged 75 years and older. The potential compensating benefit of the shorter aortic cross clamping time does not outweigh the advantages of complete revascularization. Thus, in the era of high-volume interventional approaches and minimally invasive techniques, the advantages of complete revascularization need to be considered.

Right ventricular function after brain death: Response to an increased afterload

OBJECTIVE A major cause of early postoperative morbidity and mortality after cardiac transplantation is right ventricular (RV) failure which is attributed to the inability of the donors RV to acutely compensate for the recipients elevated pulmonary vascular resistance. This study was performed to determine: (1) the acute effects of brain death on the RV function; and (2) the adaptation potential of the RV to a progressive increase in RV afterload. METHODS In 13 anesthetized, open-chest dogs (eight with brain death vs. five control with sham operation), brain death was induced by inflation of a subdural balloon catheter. Heart rate, RV systolic and end-diastolic pressure (RVSP, RVEDP), pulmonary arterial pressure (PAP), and cardiac output (CO), and pressure-length loops (sonomicrometry) were recorded. Afterload increase was induced 2 h after brain death induction by constriction of the pulmonary artery with an increase in RVP from 25 to 50 mmHg in 5 mmHg steps. RESULTS Cushing phenomenon occurred within a few minutes after brain death induction, with a significant increase of HR (229 +/- 10 vs. 89 +/- 6 min(-1), P < 0.001), CO (3.2 +/- 0.2 vs. 1.7 +/- 0.1 l/min, P < 0.001), PAP (30.4 +/- 2.5 vs. 15.5 +/- 1.3 mmHg, P < 0.01) RVSP (55 +/- 5 vs. 23 +/- 2 mmHg, P < 0.001) and RVEDP (7.4 +/- 0.9 vs. 3.3 +/- 0.6 mmHg, P < 0.001). All these values were also significantly (P < 0.01) higher than the time corresponding values of the control group. The analysis of the pressure-length loops showed a hypercontractile state. Within 15-60 min, all parameters turned to baseline and remained stable for up to 2 h. When afterload was increased progressively, RVEDP increased markedly in the brain death and slightly in the control group (9.4 +/- 0.7 vs. 4.2 +/- 1.1 mmHg, P < 0.01, at RVSP = 50 mmHg). On the other hand, the increase of peak positive dP/dt was significantly higher in the control group (430 +/- 37 vs. 644 +/- 55 mmHg/s, P < 0.01, at RVP = 50 mmHg). However, global RV pump function characterized by CO and stroke work was similar in both groups. While regional RV contractility remained unchanged in the brain death group in terms of pressure-length relationships, RV contractility significantly increased in the control group. CONCLUSION (1) Brain death per se does not result in an acute impairment of RV function. (2) While control animals adapt to an increased afterload by the homeometric, as well as the heterometric regulation, after brain death, an increase in RV preload follows elevations in RV afterload by the Frank-Starling mechanism subserving the increased stroke work required to ensure unchanged pump function.

Interruption of bronchial circulation leads to a severe decrease in peribronchial oxygen tension in standard lung transplantation technique

OBJECTIVE In clinical practice lung transplantation is the only procedure where the transplanted organ is left without its own arterial perfusion. With the interruption of the bronchial arteries the nutritive support is dependent on collateral flow by the pulmonary artery and the oxygen tension of desaturated central venous blood, representing an abnormal physiology. METHODS To analyze this problem systematically, we used a standard single left lung transplantation model in the pig (n = 12). In accordance with the clinical standard, lung preservation was performed with modified Euro-Collins solution with addition of prostacycline. The duration of ischemia was set to 4 h. Before and after single left lung transplantation tissue oxygen tension in the peribronchial tissue was measured with Licox tissue pO2 microprobes. For validation, the myocardial tissue oxygen tension was recorded simultaneously. The hemodynamic assessment included continuous flow measurement of the left and right pulmonary artery using Transsonic ultrasound flow probes. After transplantation the animals were observed for 4 h. For hypothetic augmentation of collateral blood flow to the peribronchial tissue we administered Nitric oxide (10 ppm) to the ventilation in six pigs (group B). Six pigs (group A) served as a control without the addition of nitric oxide (NO). All pigs were ventilated with a FiO2 of 0.5 resulting in paO2 values between 160 and 200 mmHg. RESULTS In both groups single lung transplantation led to a significant decrease in peribronchial tissue oxygen tension throughout the observation period. Pre-Tx values of peribronchial tissue oxygen tension (38.31 +/- 6.56 mmHg) decreased to 9.72 +/- 2.55 mmHg in group A and 10.3 +/- 3.61 mmHg in group B after 4 h, which could not be altered by a FiO2 of 1.0 (P < 0.0001). The addition of NO in group B led to a significantly augmented flow in the left pulmonary artery (0.63 +/- 0.31 l/min in group B vs. 0.46 +/- 0.26 l/min group A, P < 0.001) representing 67 vs. 49% of the pre-Tx flow in groups B and A, respectively, but the peribronchial tissue oxygen tension was not influenced (P > 0.05). In both groups A and B, the central venous pO2 did not differ in the postoperative period (41.83 +/- 3.27 mmHg group A vs. 43.26 +/- 2.98 mmHg group B) and was kept in a comparable range to the pretransplantation values (45.23 +/- 3.41 mmHg pre-Tx). CONCLUSIONS The persistence of a very low peribronchial tissue oxygen tension in the early phase after lung transplantation cannot be influenced by improved pulmonary artery flow and solely relates to the central venous pO2, which cannot be augmented by the addition of NO. This mechanism might be a trigger for anastomotic healing problems, infectious complications and later development of obliterative bronchiolitis (OB).

High defibrillation threshold in patients with implantable defibrillator: how effective is the subcutaneous finger lead?

OBJECTIVE Even in the era of high output implantable cardioverter defibrillator (ICD) devices, a certain proportion of patients cannot be successfully defibrillated with 10 J safety margin. In practice, either the use of a single- or double-coil lead does not guarantee successful termination of induced ventricular fibrillation. Therefore, we investigated the effectiveness of the subcutaneous finger lead placed at the subcutaneous tissue dorsal to the left ventricle in terms of defibrillation threshold (DFT) lowering. METHODS Two thousand, eight hundred and three consecutive, unselected patients underwent first-time ICD implantation or ICD device exchange from 6/1999 through 3/2007. The mean age of the patients was 65.4 years. A total of 79.3% of the patients were male. The only implanted subcutaneous lead was the 6996 model by Medtronic Inc. RESULTS One hundred and seventy-seven patients (6.3%) received a subcutaneous finger lead implantation. According to the current institutional DFT testing protocol, any failure of the two standard DFT tests in first-time ICD implantation or a failure at the single test in ICD exchange operations was the trigger for subcutaneous finger lead implantation. The proportion of subcutaneous finger lead implantations increased parallel to a markedly larger amount of implantations. Since high output devices became standard, the implantation number of subcutaneous finger leads decreases. The mean of unsuccessful DFTs prior to subcutaneous finger lead implantation was 27.2+/-5.3 J. After subcutaneous finger lead implantation, the mean successful DFT was 17.9+/-3.3 J. No complication due to subcutaneous finger lead implantation occurred. CONCLUSION The subcutaneous finger lead is a quick, safe and effective method for DFT lowering.

Ruptured pseudoaneurysm of the pulmonary artery--rare manifestation of a primary pulmonary artery sarcoma.

A 64-year-old male developed chest pain while gardening. Aortic dissection and coronary artery disease were excluded but chest computed tomography (CT) scan showed an aneurysmic enlargement of the pulmonary artery and a fluttering structure within. He underwent immediate sternotomy for replacement of the pulmonary artery. Histology showed an intimal sarcoma of both branches of the pulmonary artery. The pulmonary artery was replaced by a T-shaped Gore-Tex-prosthesis.

Efficiency of a computer network in the administrative and medical field of cardiac surgery : concept of and experience with a departmental system

We report on a pilot project implementing electronic data processing (EDP) in the Department of Cardiac Surgery of the University of Heidelberg, based on a concept of complete integration of a medical database system into everyday clinical routine. A computer network was installed and has been in use since August 1988 as a department system supporting both the administrative and the medical side of the department (documentation, information, research, archives, organization, secretarial office, billing, statistics and communication). With a computer-assisted documentation system and standardized data acquisition, nearly 80% of letters and reports on operations are written automatically without any further need for dictation. Automatic computer controlled follow-up has been initiated to cover all patients operated on in our hospital. The complete integration of a new method of clinical documentation and EDP into everyday clinical routine and the extensive use of computer-derived information have proved to be significant advances. Our practice of computer-assisted information management and departmental organization serves the patient by; (1) providing up-to-date valid information for the clinical staff; (2) establishing and stabilizing contact and communication with physicians elsewhere, e.g. cardiologists; (3) facilitating pre- and postoperative contact with patients; (4) helping to optimize medical treatment by routine statistical data analysis (quality assurance); (5) creating a clear and logical computer-assisted departmental organizational structure; (6) permitting long-term evaluation of operative results based on a standardized computer-controlled follow-up procedure; (7) improving the quality of medical and administrative data.

Left atrial wall dissection, mitral valve prosthesis dehiscence and pericardial hematoma: complex findings after successful cardiac resuscitation

Sirs, A 84-year-old woman, under stable condition after mitral valve replacement with a Hancock bioprosthesis for severe mitral regurgitation secondary to partial rupture chordae tendineae with flail P2 segment with no evidence of papillary muscle compromise, and a saphenous vein graft to the left anterior descending coronary artery was transferred after surgical procedure to the internal medicine intensive care unit. The patient was under permanent mechanical ventilation after successful cardiopulmonary resuscitation in the setting of an acute non-ST elevation myocardial infarction that took place 5 days before surgery. Preserved left ventricular systolic function was confirmed with laevocardiography and with echocardiography during follow-up. Clinical course was stable until 8 days after surgery, when she suddenly deteriorated hemodynamically requiring cardiopulmonary resuscitation. A comprehensive transthoracic and transesophageal echocardiographic examination conducted after successful resuscitation showed a posterior dehiscence of the bioprosthesis with severe para-prosthetic leak, a large hematoma localized posterior to the left ventricle and to the left atrium (Fig. 1a–c, Movies 1–3). This diagnosis was thereafter also documented in a computed tomography conducted during preparation for intervention (Fig. 1d, Movie 4). An emergency surgery conducted afterwards confirmed all but one diagnosis, the effusion at the left atrium was not a pericardial but an intramural hematoma. By reviewing digital images of transesophageal examination offline, a definite pericardial line (Fig. 1a, arrow) could be clearly seen. Surgical repair was attempted, but no substantial compact atrial tissue could be found that would hold the suture, even with use of corresponding surgical patches. Despite heroic efforts, surgery was unsuccessful. Ventricular rupture, valvular dehiscence and atrial dissection are possible complications due to pronounced tissue friability. This condition can be found in older ages, infectious states, myxomatous mitral valve, tissue calcifications, several connective tissue disorders [1], thoracic trauma, cardiopulmonary resuscitation and in acute postoperative phase. Left ventricular rupture after mitral valve replacement is a rare and lethal complication, with an incidence of 0.24% and mortality of 61.5% [2]. Left atrial dissection after mitral valve operation occurs in approximately 0.8% of cases [3]. Higher perioperative risks of cardiac surgical procedures in older ages compared to younger patients are acceptable, with good midand long-term survival. However, combined procedures and increased comorbidity require more resources and have a higher in-hospital mortality [4]. Transesophageal echocardiography is a valuable tool Electronic supplementary material The online version of this article (doi:10.1007/s00392-009-0087-0) contains supplementary material, which is available to authorized users.

Surgical Treatment of Aortic Valve Endocarditis With Left Ventricular-Aortic Discontinuity

BACKGROUND The periannular expansion of infection is a serious complication of infective endocarditis associated with high morbidity and mortality. The present study evaluates the results of aortic annular reconstruction in active infective endocarditis with left ventricular-aortic discontinuity. METHODS Left ventricular-aortic discontinuity was diagnosed by echocardiography in 25 (21 men, 4 female; mean age 60.2 ± 13.2 years) of 269 patients who underwent surgery for active native or prosthetic aortic valve endocarditis between January 2001 and October 2011. Seventeen (68%) and 8 (32%) patients had native and prosthetic valve endocarditis, respectively. Aortic root abscesses were radically debrided in all patients. The aortic annulus was reconstructed using autologous pericardium in 20 patients and a Dacron patch in 2. Isolated aortic valves were replaced with a bioprosthesis in 9 (36%) patients and a mechanical prosthesis in 13 (52%). Mechanical composite grafts were implanted in 3 (12%) patients. The mean follow-up was 29.1 ± 23.6 months and complete. RESULTS Thirty-day mortality was 20% (n = 5). Survival at 3 years was 80% ± 8% with no significant difference between native and prosthetic valve endocarditis (log-rank, p = 0.69). Endocarditis did not recur during follow-up. CONCLUSIONS Despite procedural progress, surgery for aortic valve endocarditis with left ventricular-aortic discontinuity remains associated with significant in-hospital mortality, but mid-term survival after the perioperative period is good. Annular reconstruction with a pericardial patch is technically safe.

Stabilität des Euro-Score als Instrument zur Identifikation von Patientenrisikogruppen – Abhängigkeit des verwendeten Dokumentationssystems

From the different methods for risk adjustment, scores allow a rough classification of the patients. The Euroscore represents one of the most modern scores. The most recent version of the documentation system of the German Society for Thoracic and Cardiovascular Surgery may be used without extended extra-work to evaluate the Euroscore despite the presence of various limitations. The investigation of the scores with nearly complete adaptation of the variables of the quality assurance documentation to the original definition showed no substantial differences between the score groups. However, many methodological implications favor the development of self-evaluated models to obtain a most recent weight for each risk factor and to be able to take into account new therapeutical options. These models can be evaluated by the existing database and extended by the most recent data.From the different methods for risk adjustment, scores allow a rough classification of the patients. The Euroscore represents one of the most modern scores. The most recent version of the documentation system of the German Society for Thoracic and Cardiovascular Surgery may be used without extended extra-work to evaluate the Euroscore despite the presence of various limitations. The investigation of the scores with nearly complete adaptation of the variables of the quality assurance documentation to the original definition showed no substantial differences between the score groups. However, many methodological implications favor the development of self-evaluated models to obtain a most recent weight for each risk factor and to be able to take into account new therapeutical options. These models can be evaluated by the existing database and extended by the most recent data. Von verschiedenen Verfahren für die Risikoadjustierung erlauben Scores eine grobe Klassifikation der Patienten. Der Euro-Score stellt einen der modernsten Scores dar, dessen Einsatz trotz bestehender Limitationen auch ohne aufwendige Zusatzerfassung der in der derzeit gültigen Fassung der bundesweiten Qualitätssicherung Herzchirurgie fehlender Information gerechtfertigt erscheint. Die Untersuchung des Scores unter nahezu vollständiger Adaptation der Variablen an die Originaldefinition und der über die Definition innerhalb der bundesweiten Qualitätssicherung Herzchirurgie modifizierten Version ergab keinen erheblichen Unterschied der Gruppierungen. Dennoch sprechen zahlreiche methodische Implikationen für die Entwicklung eigener Modelle, um ein möglichst aktuelles Gewicht der Risikofaktoren, aber auch um neue Verfahren und Behandlungskonzepte berücksichtigen zu können. Diese Modelle können anhand der bereits bestehenden Datenbank evaluiert und um jeweils aktuelle Daten ergänzt werden.

Septic rupture of the ascending aorta after aortocoronary bypass surgery

We describe an exceptional case of non-fatal septic rupture of the ascending aorta in a patient with sternal dehiscence, deep sternal wound infection (DSWI) and pleural empyema after aortocoronary bypass surgery. Routine follow-up computed tomography (CT) detected a mediastinal pseudoaneurysm originating from the ascending aorta. Thereby, massive and irregular sternal bone defects and contrast-enhancing mediastinal soft tissue suggest osteomyelitis and highly-active and aggressive DSWI as initial triggers. Urgent thoracotomy 1 day later included ascending aorta reconstruction, total sternum resection and broad wound debridement. Follow-up CT 1 year later showed a regular postoperative result in a fully recovered patient.