Magnetic resonance imaging of atherosclerotic plaque with ultrasmall superparamagnetic particles of iron oxide in hyperlipidemic rabbits

BACKGROUND

Based on the observation that ultrasmall superparamagnetic particles of iron oxides (USPIOs) are phagocytosed by cells of the mononuclear phagocytic system, the purpose of this study was to evaluate their use as a marker of atherosclerosis-associated inflammatory changes in the vessel wall before luminal narrowing is present.

METHODS AND RESULTS

Experiments were conducted on 6 heritable hyperlipidemic and 3 New Zealand White rabbits. 3D MR angiography (MRA) of the thoracic aorta was performed on all rabbits by use of a conventional paramagnetic contrast agent that failed to reveal any abnormalities. One week later, all rabbits except 1 of the hyperlipidemic animals were injected with a USPIO contrast agent (Sinerem, Guerbet) at a dose of 1 mmol Fe/kg. 3D MRA data sets collected over the subsequent 5 days showed increasing signal in the aortic lumen. Whereas the aortic wall of the control rabbits remained smooth and bright, marked susceptibility effects became evident on day 4 within the aortic walls of hyperlipidemic rabbits. Ex vivo imaging of aortic specimens confirmed the in vivo results. Histopathology documented marked Fe uptake in macrophages embedded in atherosclerotic plaque of the hyperlipidemic rabbits. Electron microscopy showed multiple cytoplasmic Fe particles in macrophages. No such changes were seen in control rabbits or in the hyperlipidemic rabbit that had not received Sinerem.

CONCLUSIONS

USPIOs are phagocytosed by macrophages in atherosclerotic plaques of the aortic wall of hyperlipidemic rabbits in a quantity sufficient to cause susceptibility effects detectable by MRI.

Surgery for acute type a aortic dissection: comparison of techniques

OBJECTIVE

In order to determine the optimal surgical strategy for acute ascending aortic dissection, the graft inclusion technique was compared with the open resection technique.

METHODS

Between 1985 and 1995 a consecutive series of 193 patients (77% male, mean age 58 years) had emergency surgery during a mean interval of 13.2 h after onset of symptoms. Graft replacement of the ascending aorta was performed in all patients (supracoronary graft 143/193=74%, aortic root replacement 50/193=26%, aortic valve replacement 73/193=38%, arch replacement 44/193=20%) The open resection technique was applied in 93 patients and the inclusion technique in 100 patients with a Cabrol-shunt in 26%. Preoperative risk factors were equally distributed between groups (inclusion technique vs. open technique): left ventricular ejection fraction<45% (13 vs. 2%, not significant (n.s.)), neurological deficit (31 vs. 25%; n.s.), systolic blood pressure<90 mm Hg (20 vs. 15%, n.s.) pericardial tamponade (25 vs. 9%, n.s.), renal failure (6 vs. 4%; n.s.).

RESULTS

The overall early mortality was 24%. Following graft inclusion it was 31% compared with 16% in the open technique group (P=0.0154). Postoperative complications (graft inclusion vs. open technique): myocardial infarction (9 vs. 12%, n.s.), low cardiac output (40 vs. 32%, n.s.), reexploration for hemorrhage (23 vs. 25%, n.s.). Survival at 8 years was significantly increased in the open technique group (P=0.0300). Pseudoaneurysm formation occurred in 3% of patients and only after graft inclusion. Freedom from reoperation was 80% at 8 years and did not differ between groups. Graft inclusion was an independent significant predictor of early (P=0.0069; relative risk=2.3673) and late mortality (P=0.0119; relative risk=2.0981).

CONCLUSIONS

Surgery of acute ascending aortic dissection still carries a considerable early mortality whereas the late outcome is satisfactory. The open resection technique is the method of choice showing superior early and late results and avoiding pseudoaneurysm formation. The inclusion technique may be indicated in situations with increased risk of bleeding. A consequent decompression of the perigraft-space could reduce the rate of pseudoaneurysms.

Use of an emboli containment and retrieval system during percutaneous coronary angioplasty in native coronary arteries

BACKGROUND

Prevention of distal embolisation during percutaneous coronary revascularisation may be necessary to reduce postinterventional morbidity and mortality.

METHODS AND RESULTS

We employed a newly developed emboli containment and retrieval system in native coronary arteries during percutaneous coronary angioplasty and stenting in 39 selected patients (mean age 58.9 +/- 10.1 years, 11 females) presenting with acute (n = 22; 8 LAD, 3 LCX, 11 RCA), subacute (n = 7; 2 LAD, 2 LCX, 3 RCA) or chronic (n = 6; 2 LAD, 4 RCA) total or subtotal occlusion of an infarct-related vessel, or with severe stenosis and symptoms of unstable angina (n = 4; 2 LAD, 2 RCA). Protection device-assisted angioplasty with stent implantation was uneventful in all patients with good angiographic results and normal postprocedural flow. Intermittent aggravation of anginal pain during inflation of the occlusive balloon (from 2.5 to a maximum of 25 minutes cumulative inflation time) was observed in 19 of the 36 conscious patients (7 with acute, 7 with subacute and 3 with chronic occlusion, and 2 with unstable angina), but caused neither interruption of distal occlusion nor haemodynamic instability. In 31 patients the aspirates contained visible debris. Histological analysis showed particles up to 12 mm in size, consisting of necrotic core, inflammatory cells, cholesterol debris, and old and fresh thrombi. In 8 patients the aspirated particles were too small to allow microscopic diagnosis or debris was absent.

CONCLUSIONS

This preliminary report demonstrates the feasibility of using a protection device in native coronary arteries to prevent distal embolisation of particulate matter that is mobilised during percutaneous interventions. To the extent that this material contributes to the mechanisms of distal embolisation, noreflow and infarction, this device may help to reduce such complications. Appropriately designed trials are required to assess the clinical benefit of this system.

FloSeal: a new hemostyptic agent in peripheral vascular surgery

BACKGROUND

Bleeding is a common and often severe side-effect in vascular surgery. The use of glue is widely accepted to achieve a dry surgical field. The application of sealant is limited when the surface is covered with blood. Aim of this study was to evaluate a new sealant (FloSeal) in patients undergoing vascular surgery.

PATIENTS AND METHODS

Between June 1998 and July 1999 a total of 17 patients with peripheral vascular interventions was included in this investigation. Effectiveness was measured by bleeding severity prior and after application, time to hemostasis, amount of fusion matrix necessary for hemostasis, the potential need for additional hemostatic measures, or the need for reoperations to control the bleeding.

RESULTS

In 15 out of 17 patients bleeding was controlled with FloSeal alone, two patients required further surgical or hemostatic treatment. There were no local or systemic complications after use of this product.

CONCLUSION

FloSeal is an advantageous hemostatic tool.

[Special problems after lung transplantation: walking a tightrope between infection and graft rejection]

Between November 1992 and September 1999 84 lungs have been transplanted at University Hospital Zurich. Currently the 1-year survival rate is up to 85%. However, long-term success is limited by the development of chronic rejection in the form of bronchiolitis obliterans. The risk factors are repeated episodes of acute rejection and infections, due to cytomegalovirus in particular. Both can occur in asymptomatic patients and are sometimes detected only by transbronchial lung biopsy. At the Zurich Lung Transplant Centre biopsies are performed as surveillance biopsies in asymptomatic patients in the first 6 months after transplantation, for clinical indications and as follow-up biopsies after a pathological result. Open lung biopsies are performed for special indications only. We evaluated 408 transbronchial biopsies taken between November 1992 and September 1999. Relevant findings were present in 46% of biopsies in symptomatic patients. Relevant acute rejection episodes were diagnosed in 15% of surveillance biopsies. Overall, 72% of acute rejection episodes requiring therapy and 33% of biopsies detecting cytomegalovirus were found in surveillance biopsies. 7 of 11 late (> 45 days postoperative) and 1 of 5 early (< or = 45 days postoperative) open lung biopsies revealed new diagnoses. Transbronchial biopsy after lung transplantation is at present the gold standard for diagnosis of acute rejection and cytomegalovirus pneumonia of the lung.

[Surgical repair of aortic coarctation in adults over 30 years of age]

Coarctation of the aorta is nowadays rarely observed among adult population, as it is usually detected and treated during infancy. The natural history of this disease however is known to lead to early death due to the consequences of severe arterial hypertension. We report on 3 patients older than 30 years, recently operated on in our cardiosurgical units. Two of them were foreigners recently arrived in Switzerland, of 46 and 32 years old respectively. The medical examination highlighted severe hypertension and bilateral absence of femoral pulses. The third patient was a Swiss citizen and had a similar examination. Chest X-rays clearly showed rib notching, and the suspected diagnosis was confirmed with angiography. Three different surgical techniques were chosen, according to the peroperative situation. In one case, the stenosis was resected and an end-to-end anastomosis could be performed. In another case, the occlusion was complete and extended over 3 centimeters. The resected segment was replaced by a prosthetic graft. In the third case, we performed a synthetic patch graft aortoplasty. Postoperative care were simple in every cases. Coarctation of the aorta must be evoked among the possible etiologies of severe hypertension, as the surgical treatment is of real benefit and with reduced morbidity.

Apoptosis induced by ischemia and reperfusion in experimental lung transplantation

BACKGROUND

Apoptosis is a distinct form of single-cell death in response to injury. Time course of apoptosis in lung parenchymal cells during posttransplant reperfusion and the influence of oxygen content during preservation on apoptosis of parenchymal cells are studied.

METHODS

Orthotopic syngenic single left lung transplantation was performed in male Fischer (F344) rats after 18 hours of cold ischemia (n = 5 in all groups). Apoptotic cells were stained by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) technique. Strictly TUNEL-positive pneumocytes were counted on anonymized slides by a pathologist on 100 fields (x400) per specimen (mean +/- SEM).

RESULTS

The peak of apoptotic pneumocytes occurred 2 hours after reperfusion (16.8 +/- 2.2 pneumocytes/100 fields [p/100f]; p = 0.000012 vs controls, lungs fixed after 18 hours of ischemia), whereas the lowest level of apoptotic pneumocytes was seen in lungs fixed after harvest (1.4 +/- 0.51 p/100f) and lungs not undergoing reperfusion (2.8 +/- 0.49 p/100f). Four hours after reperfusion, the number of apoptotic pneumocytes was lower than 2 hours after reperfusion (13.6 +/- 3.1 p/100f; p = 0.00032 vs controls), with a further decline at 8 hours (6.4 +/- 1.5 p/100f) and 12 hours after reperfusion (4.0 + 1.2 p/100f). Interestingly, lungs inflated with N2 before storage revealed a significantly lower level of TUNEL-positive pneumocytes 2 hours after reperfusion (8.8 2.0 p/100f) compared with lungs inflated with 100% O2 (p = 0.0052).

CONCLUSIONS

Apoptosis of pneumocytes after posttransplant lung reperfusion is a very early event. Prolonged hypothermic preservation without reperfusion, however, does not lead to an elevated rate of apoptotic pneumocytes in lung grafts.

Paravalvular leakage after mitral valve replacement: improved long-term survival with aggressive surgery?

BACKGROUND

Following mitral valve replacement, surgical closure of paravalvular leaks is usually advised in severely symptomatic patients and in those requiring blood transfusions for persisting haemolysis. However, the long-term prognosis of less symptomatic patients or those not needing blood transfusions is unknown.

METHODS

Between 1987 and 1997, we observed 96 patients with mitral paravalvular leakage. A paraprosthetic leak was diagnosed after a median time of 119 days (range: 1 day-23 years) after primary mitral valve replacement. During an average follow-up of 5 years (range: 1-23 years), 50/96 patients were referred for surgical closure.

RESULTS

Compared with patients who received conservative treatment, those referred for surgery had a significantly lower mean preoperative haematocrit (P = 0.002) with a higher proportion of patients being in the NYHA class III/IV (P = 0.03). Age, gender, left ventricular function and number and size of leaks did not differ between the groups. The 30-day postoperative mortality for valve reoperation was 6% (3/50); during follow-up three further patients died, resulting in an overall mortality rate of 12%. In the group treated conservatively there was a mortality rate of 26% (12/46). Thus, the actuarial survival for patients referred for surgery was 98, 90 and 88% after 1, 5 and 10 years, compared with 90, 75 and 68% for patients treated conservatively (long-rank P = 0.03). In addition, there was a significant increase in mean haematocrit levels (P = 0.0001) and an improvement in NYHA class III/IV symptoms (P = 0.002), vertigo (P = 0.001) and fatigue (P = 0.001) after surgery.

CONCLUSIONS

Following mitral valve replacement, a more aggressive surgical treatment is recommended for patients with paraprosthetic leaks. Surgery should be offered to less symptomatic patients, as well as those not requiring blood transfusion.

[Minimally invasive coronary bypass: optimal performance after a learning period]

Minimally invasive cardiac surgery requires a learning period before the advantages of the method can be demonstrated. We report the progress of our results over 21 consecutive months. 27 patients were considered for minimally invasive coronary bypass via a small thoracotomy. We compare the results of four consecutive groups corresponding to an initial period (July-December 1997; n = 7; 66.8 +/- 8.9 years), an intermediate period (January-June 1998; n = 4; 48.1 +/- 11.2 years), an advanced period (July-December 1998; n = 7; 62.9 +/- 7.0 years) and a current period (January-March 1999; n = 7; 59.3 +/- 10.9 years). 2 patients were converted to sternotomy during the first year of experience. The operating time was reduced from 124 +/- 14 min and 118 +/- 20 min during the initial and intermediate periods to 99 +/- 18 and 98 +/- 18 min during the last two periods. The ICU stay was 2.6 +/- 1.1 days during the initial period and diminished respectively to 1.5 +/- 0.6, 1.7 +/- 0.8 and 1.6 +/- 0.5 days during the intermediate, advanced and current periods. The postoperative hospital stay was reduced from 9.0 +/- 1.4 days to 6.3 +/- 4.6, 5.2 +/- 1.7 and 5.9 +/- 1.5 days respectively. The benefits of minimally invasive coronary bypass were estimated by comparing the results of the last two periods with those of patients operated on through a sternotomy, on a beating heart (n = 12; 62.6 +/- 8.2) or under CPB (n = 81; 63.0 +/- 8.5). In these situations, operative time was 144 +/- 41 min and 180 +/- 35 min respectively. The ICU stay was 1.5 +/- 0.6 and 2.2 +/- 0.9 days, and the postoperative hospital stay was 7.5 +/- 2.8 and 8.6 +/- 3.0 days. We conclude that a learning period is necessary before the real benefits of the minimally invasive approach to coronary disease can be demonstrated. This method will soon replace traditional sternotomy in certain indications.

Cytokine-mediated Bax deficiency and consequent delayed neutrophil apoptosis: a general mechanism to accumulate effector cells in inflammation

Neutrophils are important effector cells in immunity to microorganisms, particularly bacteria. Here, we show that the process of neutrophil apoptosis is delayed in several inflammatory diseases, suggesting that this phenomenon may represent a general feature contributing to the development of neutrophilia, and, therefore, in many cases to host defense against infection. The delay of neutrophil apoptosis was associated with markedly reduced levels of Bax, a pro-apoptotic member of the Bcl-2 family. Such Bax-deficient cells were also observed upon stimulation of normal neutrophils with cytokines present at sites of neutrophilic inflammation, such as granulocyte and granulocyte-macrophage colony-stimulating factors, in vitro. Moreover, Bax-deficient neutrophils generated by using Bax antisense oligodeoxynucleotides demonstrated delayed apoptosis, providing direct evidence for a role of Bax as a pro-apoptotic molecule in these cells. Interestingly, the Bax gene was reexpressed in Bax-deficient neutrophils under conditions of cytokine withdrawal. Thus, both granulocyte expansion and the resolution of inflammation appear to be regulated by the expression of the Bax gene in neutrophils.

Recent experience with the arterial switch operation in transposition of the great arteries

OBJECTIVE

Review of our experience with the technically demanding arterial switch operation in transposition of the great arteries in children.

METHODS

Twenty-seven children who underwent an arterial switch operation in our clinic were retrospectively reviewed. Except for one child (operated on at eight months), the operation was performed during the neonatal period. The underlying pathology was d-transposition of the great arteries in 25 children and a double outlet right ventricle of transposition type in 2. Five children had an associated ventricular septum defect and 1 aortic isthmus coarctation. The pattern of the coronary arteries was favourable in 18 children, difficult in 7 and dangerous in 3. The operation was performed in cardiopulmonary bypass for repair of the transposition and in a period of deep hypothermic circulatory arrest for repair of the intracardiac defects.

RESULTS

One child died perioperatively and 1 postoperatively (operative mortality 7%) from myocardial ischaemia following unsuccessful transfer of a dangerous pattern of coronary arteries. Another child, a low-birth weight baby, died 80 days after the operation from respiratory failure. Postoperative morbidity occurred in 10 patients and medium-term morbidity in 6 patients who presented various degrees of stenosis of a pulmonary artery. During a median follow-up of 18 months no patient required reoperation. The children are asymptomatic and thriving satisfactorily.

CONCLUSION

Because it restores the heart physiology, the arterial switch operation is considered the procedure of choice for correction of transposition of the great arteries. The operation involves acceptable mortality and morbidity. Transfer of difficult coronary artery patterns and development of stenosis on the pulmonary arteries remain problematic.

Corrective use of the 2.5-mm GFX stent for suboptimal angioplasty results in small coronary arteries

To evaluate the clinical efficacy of endoluminal stenting in the setting of percutaneous intervention for small coronary artery lesions, we reviewed our results on stenting with the 2.5-mm GFX stent (Arterial Vascular Engineering, Santa Rosa, CA) during an 18-month study period. A total of 120 patients with significant coronary artery disease in vessels </=2.6 mm were followed up clinically. Procedural success (defined as angiographic residual stenosis <20% without clinical complications) was obtained in 94% of cases. In-hospital complications were death (1%), non-Q-wave myocardial infarction (5%), and urgent repeat percutaneous intervention because of stent thrombosis (3%). During a mean follow-up of 9.8 months (range, 6-23 months), the following complications were noted: myocardial infarction (1%), clinical need for repeat intervention (13%) requiring repeat percutaneous treatment (12%) and surgical revascularization (1%). In conclusion, transcatheter application of a specifically designed stent for coronary artery disease in small vessels seems safe and efficient with a low incidence of adverse events during follow-up. Cathet. Cardiovasc. Intervent. 48:157-161, 1999.

[Cardiovascular disease in pregnancy]

There is a heterogeneous population of young women with cardiovascular disease contemplating pregnancy. Many of the conditions are rare and require teams with expertise in the management of such patients. A specific congenital or acquired cardiovascular anomaly and its physiology must be understood. The nature of prior surgical procedures and the residua and sequelae following therapy are essential to manage a pregnant woman with cardiovascular disease. Physiologic changes during pregnancy and after delivery must be known. Counseling includes maternal and fetal risk stratification and genetic counseling regarding inherited disorders. The outcome of pregnancy is favourable in many women with good functional class. These patients can be reassured. A multidisciplinary approach may be crucial to manage this population during pregnancy, labour, delivery and in the postpartum period to avoid serious maternal and fetal complications. Women with intermediate and high risk pregnancy must be followed and managed in a high risk pregnancy unit and a team from obstetricians, cardiologists, anesthetists, pediatricians, neonatologists and cardiac surgeons who are skilled in high risk pregnancies. Vaginal delivery is the method of choice in many women (class 1 woman) and cesarean section is seldom a cardiac indication. Contraindications for pregnancy are: poor maternal functional class, poor ventricular function, severe cyanosis without pulmonary hypertension (oxygen saturation < or = 85%), pulmonary vascular disease, severe mitral stenosis, severe left ventricular outflow tract obstruction, Marfan syndrome with aortic dilatation (> 40 mm) and aortic valve involvement (moderate to severe aortic regurgitation), symptomatic hypertrophic obstructive cardiomyopathy. Preconception counseling must be offered if unfavourable outcome is likely. Tubal ligation is probably the safest and most appropriate method of sterilization if there is a high risk pregnancy.

Composite graft replacement of the aortic root: long-term results, incidence of reoperations

BACKGROUND

Long-term results after composite graft replacement of the aortic root may depend on the insertion technique.

METHODS

181 consecutive patients (mean age 53 years; 153 men) operated on between 1983 and 1993 were studied. Indications for surgery were annuloaortic ectasia (n=98), acute aortic dissection (n = 46), other indications (n = 12), and various indications after previous aortic valve replacement (n = 25). Mean follow-up was 28 months. The open-button technique was performed in 74 patients (41 %) and the Bentall inclusion technique in 107 patients (59%), with a Cabrol shunt to the right atrium in 16 patients.

RESULTS

Overall survival was 75% after 7 years, significantly decreased in acute aortic dissection (p = 0.0019) and without difference between the two surgical techniques (p = 0.3166). Reoperation-free survival was 69% at 7 years and significantly decreased after acute dissection (p = 0.0421 ). Pseudoaneurysm formation only occurred in 3 patients operated with the Bentall technique not including a Cabrol shunt.

CONCLUSIONS

Long-term results are satisfactory. In acute aortic dissection survival is decreased and late reoperations more frequent. The open technique is safe in non-dissection and in acute dissection and avoids pseudoaneurysm formation. The Bentall technique combined with Cabrol shunt is indicated if there is a high risk of hemorrhage. Long-term monitoring of the aorta is mandatory in patients with acute dissection and/or Marfan disease.

Extended follow-up after atrial repair for transposition of the great arteries: a younger age at surgery improves late survival

BACKGROUND

Surgical treatment for transposition of the great arteries (TGA) usually involves anatomic repair, although atrial repair is used in cases with special coronary artery patterns.

METHODS

Records of all 239 patients surviving at least 30 days after atrial correction of TGA between 1962 and 1987 at the University Hospital in Zurich were reviewed. The mean length of follow-up time was 13.7 years (median 14.9 years; range from 0.05 to 30.1 years). The average age at surgery was 45.7 months (range from 7 days to 24.4 years). One hundred twenty-one patients had a simple TGA, whereas the remaining 118 had a complex TGA.

RESULTS

The surviving patients were in NYHA class I at time of follow-up. The most common reasons for death were systemic right ventricular dysfunction and sudden rhythm disturbances. There was a major risk for late cardiac event in patients over 3 years old at operation (p = 0.02) and also in patients with complex TGA (p = 0.03). However, date of surgery, previous surgery, or the postoperative requirement for a pacemaker did not greatly affect late cardiac mortality.

CONCLUSIONS

Although the procedure of choice for TGA is the arterial switch operation, the promising findings of the current long-term study, which reports the longest follow-up to date, indicate that the atrial switch operation is a good alternative procedure for the rare cases where the use of arterial switch procedures is limited.

Five-year outcome in patients with isolated proximal left anterior descending coronary artery stenosis treated by angioplasty or left internal mammary artery grafting. A prospective trial

BACKGROUND

Percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass surgery (CABG) improve the clinical status of patients with isolated proximal left anterior descending coronary artery stenosis. At 2 years, only additional revascularization was more frequently required after PTCA.

METHODS AND RESULTS

We monitored 134 patients randomized to PTCA (n=68) or CABG (n=66) for </=5 years. End points were death, myocardial infarction, need for additional revascularization, clinical status, and medical treatment. At 5 years, 6 patients (9%) had died in the PTCA group versus 2 (3%) in the CABG group (P=0.12). One patient in each group died of a cardiac cause. Myocardial infarction was more frequent after PTCA (15% versus 4%; P=0.0001), but Q-wave infarction was not (6% in the PTCA group versus 3% in the CABG group; P=0.8). Additional revascularization was required in 38% of patients in the PTCA group versus 9% in the CABG group (P=0.0001). Functional status was comparable, with 6% of patients after PTCA and 3% after CABG in functional class III or IV. Finally, after PTCA or CABG, 62% and 91% of patients, respectively, were free of events (P=0.0001).

CONCLUSIONS

The 5-year prognosis of patients with isolated proximal left anterior descending coronary artery stenosis is good. Both PTCA and CABG improve clinical status, but revascularization was needed more frequently after PTCA. There is an excess incidence of non-Q-wave myocardial infarction in the PTCA group that does not affect the vital or symptomatic outcome.

Immobility as a major cause of bone remodeling in residents of a long-stay geriatric ward

Residents of a long-stay geriatric ward at the University Hospital Basel were included in a study to investigate the effects of hypovitaminosis D and immobility. All 91 women (mean age 82.5 years) and 92 men (mean age 78.7 years) were enrolled in the study. Measurements included bone resorption, as measured by urinary deoxypyridinoline (dpd), serum 25-hydroxyvitamin D (25OHD), serum intact parathyroid hormone (iPTH), and their correlations with a four grade mobility score. Mobility score reflected the degree of weight bearing, ranging from walking independently to primarily bed bound. In 86% of all residents, serum 25OHD levels were below the normal limit of 12 ng/ml. Secondary hyperparathyroidism (HPT) was detected in 24% of all patients, using 55 pg/ml as the upper limit for serum iPTH. No significant correlation was found between urinary dpd and serum 25OHD or serum iPTH. Mobility index and both urinary dpd (f: P = 0.001, r = 0.37; m: P < 0.0001, r = 0.47) and serum calcium (female: P = 0.007, r = 0.28; male: P = 0.02, r = 0.24) were positively related. In institutionalized elderly people with a high prevalence of vitamin D deficiency serum intact PTH levels did not correlate with bone resorption as measured by urinary deoxypyridinolin. However, more immobile subjects had significantly higher excretion rates for urinary dpd and higher serum calcium levels. Our results suggest that in elderly people immobility may contribute to bone loss that might preempt the development of secondary HPT through elevation of serum calcium.

Differentiation-related expression of the Thomsen-Friedenreich glycotope in developing human lung and in lung carcinoma: lack of association with malignancy

BACKGROUND

It has been proposed that the Thomsen-Friedenreich glycotope represents a general carcinoma-associated antigen and a candidate for the development of a tumor vaccine. However, the expression of the unmasked and masked (sialylated) forms in lung carcinomas, as well as in developing and adult human lung, has not been documented sufficiently.

METHODS

Sections from 82 lung carcinomas, including squamous cell carcinomas, adenocarcinomas, and large cell and small cell carcinomas, as well as sections of developing and adult human lung were studied using the lectin amaranthin and a monoclonal antibody.

RESULTS

All lung carcinomas but one bronchiolo-alveolar carcinoma were unreactive for the Thomsen-Friedenreich glycotope, whereas its sialylated form was detectable in well-differentiated squamous cell carcinomas and adenocarcinomas, including bronchiolo-alveolar carcinomas. Both unmasked and masked Thomsen-Friedenreich glycotopes were undetectable in large cell and small cell lung carcinomas. In all developmental stages of lung, the Thomsen-Friedenreich glycotope was expressed only in epithelia of the most peripheral parts of the bronchial tree, whereas its sialylated form was expressed in epithelia of all parts of the bronchial tree. In adult lung, the Thomsen-Friedenreich glycotope was expressed in pneumocytes, whereas its sialylated form was expressed ubiquitously in all epithelia.

CONCLUSIONS

The Thomsen-Friedenreich glycotope in human lung represents a differentiation antigen, rather than a carcinoma-associated antigen. The sialylated form is expressed constitutively in both developing and adult lung and well-differentiated lung carcinomas. Thus, the Thomsen-Friedenreich glycotope is of limited value in the diagnosis of lung carcinoma, and there is no rationale for a Thomsen-Friedenreich glycotope-based immunotherapy for patients with this disease.

Conservative treatment of the aortic root in acute type A dissection

OBJECTIVE

In acute type A dissection long-term results of conservative aortic root surgery were compared with the outcome of primary valve and/or root replacement.

METHODS

Between 1985 and 1995, 199 patients (mean age 59 years, 154 men) were operated on. The aortic root was involved in the dissection process and valve incompetence of varying degree was present without exception. Replacement of a proximal aortic segment was standard procedure in all patients. The aortic valve was preserved in 126 patients: commissural suture resuspension (12 patients), root reconstruction with GRF-glue (gelatine-resorcin-formaldehyde/glutaraldehyde-glue) (114 patients). Valve replacement was performed in 73 patients (50 composite grafts, 23 valve prostheses with separate supracoronary grafts). Preoperative risk factors (valve replacement vs. preservation): coronary artery disease (11 vs. 8%, NS), tamponade (18 vs. 17%, NS), unstable hemodynamics (22 vs. 15%, NS), renal failure (4 vs. 6%, NS), neurologic disorder (19 vs. 32%, NS).

RESULTS

The overall early mortality was 23.6% (47/199 patients) and increased after commissural suture resuspension compared with GRF-glue reconstruction (P = NS). Parameters of the early postoperative period did not differ between conservative treatment and root/valve replacement: low cardiac output, 34 versus 38% (P = NS); myocardial infarction, 10 versus 11% (P = NS); hemorrhage, 25 versus 23% (P = NS); duration of intensive care (P = NS). Survival was 61% after 8 years without difference between the two principal treatment groups (P = NS) and between the two conservative subgroups (P = NS). At 2 years, GRF-glue reconstruction had an increased freedom from reoperation on the aortic root (92 vs. 70%, P = 0.0253) and event free survival (77 vs. 41%, P = 0.0224) compared with suture resuspension. Commissural suture resuspension was an independent, significant predictor for reoperation (P = 0.0221, relative risk = 4.7130).

CONCLUSION

Surgery for acute type A dissection still carries a considerable early risk. Preservation of the aortic root is safe in the absence of Marfan or annuloaortic ectasia, but a certain incidence of reoperations on the aortic valve and the aortic root has to be accepted. Root reconstruction using GRF-glue is the method of choice and is superior to suture resuspension, with a significantly better reoperation-free and event-free survival.

Bronchiolitis obliterans organizing pneumonia associated with polymyalgia rheumatica

The association of bronchiolitis obliterans organizing pneumonia (BOOP) with polymyalgia rheumatica is rare, and only one case has previously been described. This study reports on the case of an 80 yr-old male who presented with malaise, nonproductive cough and exertional dyspnoea for several weeks, along with a history of bilateral shoulder and pelvic girdle pain of several months' duration. The chest radiograph revealed a pneumonic infiltrate in the right lower lobe, which was unresponsive to antibiotics. Bronchoscopy, bronchoalveolar lavage and a transbronchial lung biopsy established the diagnosis of BOOP. The patient improved consistently on steroids. As in other connective diseases, organizing pneumonia may be one of the early manifestations of polymyalgia rheumatica.

Congenital subaortic stenosis by accessory mitral valve tissue, recognition and management

Accessory mitral valve tissue as the single cause for left ventricular outflow tract obstruction is a very rare cardiac malformation in normally connected hearts. We report a case in which this condition was present as single cause for left ventricular outflow tract obstruction. The surgical technique is described and a review of the literature presented.

Tissue engineering in cardiovascular surgery: MTT, a rapid and reliable quantitative method to assess the optimal human cell seeding on polymeric meshes

OBJECTIVE

Currently used valve substitutes for valve replacement have certain disadvantages that limit their long-term benefits such as poor durability, risks of infection, thromboembolism or rejection. A tissue engineered autologous valve composed of living tissue is expected to overcome these shortcomings with natural existing biological mechanisms for growth, repair, remodeling and development. The aim of the study was to improve cell seeding methods for developing tissue-engineered valve tissue.

METHODS

Human aortic myofibroblasts were seeded on polyglycolic acid (PGA) meshes. Cell attachment and growth of myofibroblasts on the PGA scaffolds with different seeding intervals were compared to determine an optimal seeding interval. In addition, scanning electron microscopy study of the seeded meshes was also performed to document tissue development.

RESULTS

There was a direct correlation between cell numbers assessed by direct counting and MTT(3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltertra-zoliu m bromide) assay. Both attach rate and cell growth seeded on meshes with long intervals (24 and 36 h) were significantly higher than those seeded with short intervals (2 and 12 h) (P<0.01), there was no significant difference between 24- and 36-h seeding interval. Scanning electron microscopy also documented more cell attachment with long seeding intervals resulting in a more solid tissue like structure.

CONCLUSION

It is feasible to use human aortic myofibroblasts to develop a new functional tissue in vitro. Twenty-four hours is an optimal seeding interval for seeding human aortic myofibroblasts on PGA scaffolds and MTT test is a rapid and reliable quantitative method to assess the optimal human cell seeding on polymeric meshes.