Pneumonectomy for lung cancer in heart transplant recipient.

Prolonged nonspecific immunosuppression after solid-organ transplantation is associated with an increased risk of certain cancers. Review of the medical literature reveals that the combination of profound immunossuppression (triple-drug immunosuppression), a heavy smoking history, advanced age and a working exposition puts cardiac transplant recipients at increased risk for the development of aggressive lung cancer. These tumors in cardiac transplant recipients carry a poor prognosis. We present one case of bronchogenic carcinoma in a cardiac transplant patient. The patient was operated to resect the tumor and a long-term cure and a good quality of life should, however, be offered.

Ca(2+) handling in isolated human atrial myocardium.

Physiologically, human atrial and ventricular myocardium are coupled by an identical beating rate and rhythm. However, contractile behavior in atrial myocardium may be different from that in ventricular myocardium, and little is known about intracellular Ca(2+) handling in human atrium under physiological conditions. We used rapid cooling contractures (RCCs) to assess sarcoplasmic reticulum (SR) Ca(2+) content and the photoprotein aequorin to assess intracellular Ca(2+) transients in atrial and ventricular muscle strips isolated from nonfailing human hearts. In atrial myocardium (n = 19), isometric twitch force frequency dependently (0. 25-3 Hz) increased by 78 +/- 25% (at 3 Hz; P < 0.05). In parallel, aequorin light signals increased by 111 +/- 57% (P < 0.05) and RCC amplitudes by 49 +/- 13% (P < 0.05). Similar results were obtained in ventricular myocardium (n = 13). SR Ca(2+) uptake (relative to Na(+)/Ca(2+) exchange) frequency dependently increased in atrial and ventricular myocardium (P < 0.05). With increasing rest intervals (1-240 s), atrial myocardium (n = 7) exhibited a parallel decrease in postrest twitch force (at 240 s by 68 +/- 5%, P < 0.05) and RCCs (by 49 +/- 10%, P < 0.05). In contrast, postrest twitch force and RCCs significantly increased in ventricular myocardium (n = 6). We conclude that in human atrial and ventricular myocardium the positive force-frequency relation results from increased SR Ca(2+) turnover. In contrast, rest intervals in atrial myocardium are associated with depressed contractility and intracellular Ca(2+) handling, which may be due to rest-dependent SR Ca(2+) loss (Ca(2+) leak) and subsequent Ca(2+) extrusion via Na(+)/Ca(2+) exchange. Therefore, the influence of rate and rhythm on mechanical performance is not uniform in atrial and ventricular myocardium.

Haemodynamic changes during minimally invasive coronary artery bypass surgery using high-dose esmolol.

UNLABELLED: We aimed to investigate the effects of high-dose esmolol on haemodynamics and oxygen extraction in minimally invasive direct coronary artery bypass (MIDCAB) surgery patients. METHODS: In 18 patients, heart rate (HR), mean arterial (MAP), central venous (CVP), pulmonary capillary wedge pressure (PCWP), cardiac output (CO), and mixed venous oxygen saturation (Sv0(2)) were prospectively measured after induction of anaesthesia (T1), start of surgery (T2), during bypass grafting with beta-blockade (T3), and at the end of surgery (T4). RESULTS: Mean esmolol dose at T3 was 0.44+/-0.2mgkg(-1)min(-1). HR was unchanged, whereas significant decreases in mean CO (3.1+/-0. 8 vs 4.8+/-1.0lmin(-1)m(-2), pre-esmolol), MAP (53+/-10 vs 89+/-14mmHg), and SvO(2) (65+/-10 vs 81+/-4%) were observed during esmolol administration. All haemodynamic parameters normalized immediately after termination of esmolol (T4). CONCLUSIONS: Despite unchanged HR esmolol reduced CO and MAP suggesting a favorable reduction of myocardial oxygen consumption. Mean Sv0(2) during esmolol administration reflects an acceptable ratio of whole-body oxygen delivery and consumption. Haemodynamic changes with high-dose esmolol during MIDCAB surgery remain within safety margins.

Comparison of cardiac output assessed by pulse-contour analysis and thermodilution in patients undergoing minimally invasive direct coronary artery bypass grafting.

OBJECTIVE: To investigate the precision and accuracy of continuous pulse contour cardiac output (PCCO) compared with intermittent transcardiopulmonary (TCPCO) and pulmonary artery thermodilution (TDCO) measurements in patients undergoing minimally invasive coronary bypass surgery (MIDCAB). DESIGN: Prospective, controlled, clinical study. SETTING: University hospital. PARTICIPANTS: Twelve patients undergoing MIDCAB. INTERVENTIONS: Thirty-six measurements of PCCO and thermodilution cardiac output (CO) were simultaneously performed after the start of surgery, during bypass grafting, and at the end of surgery. TCPCO and TDCO were simultaneously assessed by three injections of ice-cold saline randomly spread over the respiratory cycle. The pulse contour device was initially calibrated with an additional set of aortic thermodilution measurements. MEASUREMENTS AND MAIN RESULTS: Absolute values of CO ranged between 1.6 and 9.2 L/min. A close agreement among the three techniques was observed at all measurements. Mean bias between PCCO and TDCO and TCPCO was 0.003 L/min (2 SD of differences between methods = 1.26 L/min) and 0.27 L/min (2 SD of differences between methods = 1.16 L/min), respectively. The correlation coefficients were r2 = 0.90 for TCPCO versus PCCO and r2 = 0.88 for TDCO versus PCCO. CONCLUSION: The results of the present study show that compared with thermodilution CO, pulse contour analysis enables accurate measurement of continuous CO in patients undergoing MIDCAB.

Calcification tendency of various biological aortic valves in an experimental animal model.

The present study aimed at investigating the influence of fixation methods on the ultrastructure and calcium content of five different aortic biovalves. Biovalves subcutaneously implanted in Wistar rats for 12 weeks demonstrated significant differences in their calcium contents. Using Scheffe tests, two different groups of biovalves could be distinguished: (i) valves with high calcium content, such as Toronto-SPV (165 +/- 42 mg/g dry tissue) and Intact (193 +/- 36 mg/g dry tissue), and (ii) valves with low calcium content, such as Mosaic (2.7 +/- 1.8 mg/g dry tissue), Freestyle (2.3 +/- 1.1 mg/g dry tissue) and Hancock-II (3.6 +/- 1.2 mg/g dry tissue) (P < 0.05). All biovalves with an ultrastructurally preserved endothelium exhibited a low calcification tendency. The data suggest that if the endothelium is lost as a result of the fixation procedure, then calcification can only be prevented by appropriate anticalcification methods.

The stentless Toronto SPV bioprosthesis for aortic valve replacement.

The Toronto SPV bioprosthesis for aortic valve replacement has been prospectively evaluated in 100 patients, since March 1993. Intraoperative transoesophageal and postoperative transthoracic echocardiography were used to assess valve function. Follow-up was complete in 74 patients at 6 months and in 38 patients at 1 year. The average valve size implanted was 26.5 mm. Some 37 patients had additional coronary artery bypass grafting surgery. The hospital mortality rate was 4%. Non-structural valve dysfunction occurred in one patient and late endocarditis in another patient required operation. There were no other valve complications. None of the patients developed clinically relevant aortic valve incompetence during follow-up and there was a significant decrease in pressure gradients, increase in valve orifice areas and decrease in left ventricular hypertrophy.

A technique for extracorporeal circulation in the Goettingen minipig allowing recovery and long-term follow-up.

The objective of our study was to establish an animal model with extracorporeal circulation (ECC) for investigations on the long-term tolerability of different pericardial substitutes using the Goettingen minipig. A combination of halothane (0.4-0.6% vaporizer setting) in oxygen and nitrous oxide (FiO2 0.33), with the opioid piritramide (75 micrograms/kg/h i.v.) was used for anaesthesia. A muscle relaxant was not administered. Due to the size of the animals (mean body weight 37.6 kg) the operative procedure was the same as in humans. Specific changes preceding or following initiation of cardiopulmonary bypass (CPB), such as inactivation of the coagulation system (400 IU heparin/kg i.v.), haemodilution, and hypothermia (32 degrees C), did not result in any complication. We did not induce cardiac arrest during CPB in order to facilitate haemodynamic stability after weaning from CPB. In three animals a temporary increase in blood pressure occurred after protamine (2.5-3.0 mg/kg i.v.) was given to reverse the heparinization. Within 60 minutes after the end of surgery all animals could be extubated when spontaneous breathing and cough reflex were present. The postoperative follow-up period of nine months was uneventful apart from one animal which developed a superficial wound in the thoracic scar area. We conclude that our technique for ECC is a safe method allowing recovery and long-term follow-up after cardiac surgery in a porcine animal model.

Tonsillar carcinoma in the early postoperative course following heart transplantation.

A 45-year-old male with end-stage dilative cardiomyopathy was referred for heart transplantation (HTx). Apart from severe heart disease the patient had an unremarkable medical history. Risk factors were heavy smoking and moderate consumption of alcohol. Preoperative screening including a thorough ENT status did not reveal any other risk factor or contraindication for heart transplantation. HTx was performed three months later. Immunosuppressive therapy consisted of triple-drug therapy and induction therapy with antithymocyte globulin. The patient had an uneventful perioperative course. One month after transplantation the patient developed a rapidly growing squamous cell carcinoma of the left tonsil with local metastasis. Because of the rapid growth and size of the tumor surgical treatment was already impossible at that early time. Despite a course of chemotherapy the tumor continued to grow; treatment was changed to radiation therapy resulting in partial remission. Cyclosporine and azathioprine dosages were reduced at the same time. 9 months following HTx the patient developed a rapidly growing recurrence. As there were no further therapeutic options, immunosuppressive therapy was completely discontinued with the patient's agreement. He died 2 months later. The rapid tumor growth and its early manifestation following HTx suggest a preexistent occult carcinoma. A more extensive and repetitive preoperative screening in HTx candidates who are heavy smokers should be considered.

[New treatment methods in heart valve surgery--the Toronto SPV stentless bioprosthesis]. / Neue Behandlungsverfahren in der Herzklappenchirurgie--Die Toronto SPV Stentlose Bioprothese.

Stentless valves may be an alternative to conventional stented bioprostheses and homografts. From all tissue valves homografts proved to have the best long term results. But homografts are not always available. Stentless bioprostheses are similar to homografts concerning in implantation technique, valve anatomy and physiologic function. The stentless design leads to remodeling of the left ventricle and the aortic root, resulting in a superior hemodynamic profile. Nevertheless long term results are required.

The Toronto SPV bioprosthesis: one-year results in 100 patients.

BACKGROUND: We studied the long-term results of heart valve replacement with the Toronto SPV bioprosthesis. METHODS: From March 1993 until July 1994 the Toronto stentless bioprosthesis was implanted in 100 selected patients with a mean age of 70.7 years. The predominant aortic valve lesion was stenosis in 94 and insufficiency in 6 cases. Eighty-eight patients received a valve 25 mm in diameter or larger. Additional coronary artery bypass grafting was performed in 37 cases. Hospital mortality was 4%. Seventy-four patients were seen at 6 months and 38 patients at 1 year follow-up. RESULTS: Structural deterioration, thromboembolism or hemorrhage were not encountered. Nonstructural dysfunction lead to reoperation in 1 patient. Another patient presented with endocarditis at 1 year postoperatively. There were no other valve-related complications. Echocardiographic mean pressure gradients ranged from 7.7 to 11.1 mm Hg postoperatively. There was a significant decrease in pressure gradients at 6 months of follow-up. Minimal aortic valve incompetence was seen in 3 patients. CONCLUSIONS: The Toronto stentless bioprosthesis has superior hemodynamics and is an excellent alternative to conventional stented bioprostheses. Long-term evaluation has to prove whether this promising new valve can live up to its expectations.

Hemodynamic assessment of the stentless Toronto SPV bioprosthesis by echocardiography.

Since March 1993 the Toronto SPVTM bioprosthesis has been implanted in 100 patients. Our prospective study evaluated the echocardiographic valve characteristics and the influence of the echocardiographic assessment on surgical technique. Transesophageal echocardiography (TEE) was applied before and during surgery, and transthoracic echocardiography (TTE) postoperatively. The average valve size implanted was 26.5 mm. Follow up was complete in 74 patients at six months and in 38 patients at one year. Pre-cardiopulmonary bypass (CPB) TEE valve sizing was accurate by +/- 1 mm in 81 patients as compared to mechanical sizing. Post-CPB valve closure was concentric in 99 patients. Minimal aortic incompetence was present in seven patients at one week, in two patients at six months and in one patient at one year. Mean pressure gradients ranged from 7.7 to 11.1 mmHg postoperatively. Overall mortality was 4%. One patient with non-structural dysfunction and another with endocarditis at one year postoperatively were reoperated successfully. At follow up there was a significant decrease in transvalvular pressure gradients and an increase in valve orifice areas. In 32 patients a decrease in left ventricular posterior wall (LVPW) hypertrophy was found (p < 0.001). There was a decrease in tissue depth and recurrence of the dynamic movement of the aortic root. It is concluded that TEE valve sizing is reliable for early valve selection. Valve incompetence is not a clinically relevant issue using the oversizing technique. Improved hemodynamics at follow up can be explained by remodeling of the aortic root and by a decrease in left ventricular hypertrophy. The excellent hemodynamic profile, resembling native aortic valve function, is impressive and has to be confirmed by long term evaluation.

Fractured strut of Björk-Shiley 70 degrees convexo-concave mitral valve prosthesis found in left coronary artery. Use of a portable transcutaneous cardiopulmonary bypass system for successful valve replacement.

Strut fractures followed by disk escape of Björk-Shiley convexo-concave valve prostheses are a well-known problem. This article discusses the case of a successfully treated patient who was admitted to our institution with extreme and prolonged cardiogenic shock. The strut was dislodged into the main stem of the left coronary artery and the disk into the iuxtarenal abdominal aorta. The intent of this report is, in particular, to illustrate the management problems. Immediately after diagnosis, circulation and oxygenation were ensured by use of a portable cardiopulmonary bypass support (CPS) system whose circulation lines were introduced subcutaneously. Thus the transfer to the operating room and the surgical intervention were able to start under controlled conditions. The disk was removed by Fogarty catheter manoevre without any problems during the same operation, using a transpericardial access to the descending thoracic aorta. In our opinion, the primary insertion of the CPS and the avoidance of an additional laparotomy in disk removal help promote the survival of such critically ill patients.