Acute Pulmonary Embolectomy Three Days following a Coronary Artery Bypass Graft Procedure

Pulmonary embolism is very rarely reported early after cardiac surgery, most probably due to full heparinisation during cardiopulmonary bypass. We report a 66-year-old man without thromboembolic history who presented three days after a coronary artery bypass grafting procedure with acute dyspnoea and haemodynamic instability. A CT scan confirmed paracentral bilateral pulmonary embolism requiring an urgent and successful embolectomy. Review of the literature confirms that pulmonary embolism may occur in up to 3% of post-cardiopulmonary bypass patients.

The possibility of pulmonary embolism must be taken into consideration in post-cardiopulmonary bypass patients with acute onset of chest pain and respiratory insufficiency.

Common Femoral Artery — Uncommon Aneurysms

Background and Aims:

Femoral artery aneurysms are rare. Their natural history, tendency to embolize or rupture are not well known.

Material and Methods:

Data of all patients seen 1996–2002 with femoral artery aneurysms at the Swiss Cardiovascular Center were analysed. Nine patients with 13 aneurysms of the common femoral artery (CFA) were identified. Only true aneurysms with a diameter of at least 2.5 cm were included. All patients were male, mean age 70 years (range: 57–85 years). Four patients had bilateral femoral aneurysms. Risk factors included hypertension (9/9), smoking (7/9). One of the aneurysms was palpable in 5/9. Four patients were asymptomatic, 5 had Fontaine class II claudication. Five patients also had an aortic aneurysm (AAA), one a thoracic aneurysm; and 6/9 popliteal aneurysms. In all patients, diagnosis was confirmed with duplex scan. Angiography was performed preoperatively.

Results:

The aneurysms were operated on electively using aneurysm secclusion and interposition grafting. There were no significant perioperative complications. Median hospital stay was 8 days.

Conclusion:

CFA aneurysms are rare. They are palpable in nearly half of the cases. They rarely cause thrombotic or embolic complications, but are almost always connected to other aneurysms. Patients with CFA aneurysms should be screened with duplex scan. Operative therapy is straightforward, few complications can be expected. Postoperative follow-up with annual duplex scans is suggested.

Spontaneous Dissection of Common Iliac Artery

Spontaneous dissection of the iliac artery is very rare but known as a complication of highenergy traumatic injuries and has been reported in connection with pregnancy, collagen diseases, and alpha-1-antitrypsin deficiency. The authors report a 42-year-old man with an acute dissection of the common iliac artery during exercise. Groin pain and claudication were the early symptoms. Computerized angiotomography was diagnostic. Operative iliac artery reconstruction was performed. A prerelease control computed tomography examination showed a dissection of the distal aorta and left iliac artery. To their knowledge, the combination of the 2 dissections has not been previously published.

Management of aortic aneurysms in patients with connective tissue disease

Acute dissection and rupture of aortic aneurysms comprise for 1-2% of all deaths in developed countries. Dilation of the aorta is caused by several different mechanisms including inherited disorders of connective tissue. Recent reports estimate that 20% of patients presenting with thoracic aortic disease do have an underlying genetic basis of disease.

Fine-tuning of substrate architecture and surface chemistry promotes muscle tissue development

Tissue engineering has been increasingly brought to the scientific spotlight in response to the tremendous demand for regeneration, restoration or substitution of skeletal or cardiac muscle after traumatic injury, tumour ablation or myocardial infarction. In vitro generation of a highly organized and contractile muscle tissue, however, crucially depends on an appropriate design of the cell culture substrate. The present work evaluated the impact of substrate properties, in particular morphology, chemical surface composition and mechanical properties, on muscle cell fate. To this end, aligned and randomly oriented micron (3.3±0.8 μm) or nano (237±98 nm) scaled fibrous poly(ε-caprolactone) non-wovens were processed by electrospinning. A nanometer-thick oxygen functional hydrocarbon coating was deposited by a radio frequency plasma process. C2C12 muscle cells were grown on pure and as-functionalized substrates and analysed for viability, proliferation, spatial orientation, differentiation and contractility. Cell orientation has been shown to depend strongly on substrate architecture, being most pronounced on micron-scaled parallel-oriented fibres. Oxygen functional hydrocarbons, representing stable, non-immunogenic surface groups, were identified as strong triggers for myotube differentiation. Accordingly, the highest myotube density (28±15% of total substrate area), sarcomeric striation and contractility were found on plasma-coated substrates. The current study highlights the manifold material characteristics to be addressed during the substrate design process and provides insight into processes to improve bio-interfaces.

Soluble type A substance in fresh-frozen plasma as a function of ABO and Secretor genotypes and Lewis phenotype

Soluble ABO blood group substance (SAS) in fresh-frozen plasma (FFP) and its cognate alloantibody titer reduction capacity (TRC) are not considered when prescribing this product for plasma exchange (PEX) therapy of ABO incompatible transplant recipients. SAS was quantified in 250 single FFPs using ELISA. Total and IgG class-specific anti-A TRCs of FFPs were measured using a microhemagglutination inhibition assay. SAS level depended not only on the A subtype (p < 0.0001) and the Secretor status (p < 0.0001), but also on the expression of ALe(b) in A1 secretors (p < 0.0001). The variation was as great as 137.6 arbitrary units (aU) for 14 A1 Le(a-b-) secretors and 1.2 aU for 6 A2 non-secretors. Homozygous expression of the A1, A2 and Secretor alleles did not increase SAS levels. Only total anti-A TRC, but not IgG class-specific TRC depended on the detected SAS level (r = 0.566, p = 0.0003).

Bovine mesenteric vein graft (ProCol) in critical limb ischaemia with tissue loss and infection

OBJECTIVES

Poor results have been reported following infrainguinal reconstructions using heterogenous grafts. The objective of this study was to assess the use of bovine mesenteric vein (ProCol) graft in patients with critical limb ischaemia (CLI), tissue loss/infection and no autologous vein available for reconstruction.

METHODS

Prospective analysis of 32 patients with CLI and tissue loss/infection, in whom reconstruction with ProCol was undertaken between October 1999 and May 2002.

RESULTS

The primary patency rate was 16% at 1 month. After thrombectomy, the secondary patency rate was 50% at 1 month and 26% at 14 months. No graft infections were seen. Aneurysmal dilatation of the graft occurred in 2 (6%). Limb salvage at 14 months was 47%.

CONCLUSION

In patients with critical limb ischaemia, tissue loss/infection and no available vein, the ProCol graft may be an alternative. However, primary patency is a problem. In situations without tissue loss/infection, where the risk of graft infection is less, prosthetic material may be a better alternative.

The Sorin Pericardial Bioprosthesis: The Stentless Aortic Valve with Excellent Hemodynamic Performance

Fragestellung: Die Sorin PericarbonTM Freedom Stentless Aortenklappe verfügt über eine sehr gute hämodynamische Funktion und eine hohe Widerstandsfähigkeit. In dieser Studie stellen wir die früh- und mittelfristigen Resultate mit dieser Klappenprothese vor. Methodik: 31 konsekutive Patienten (16 Frauen und 15 Männer) wurden nach Implantation einer Sorin PericarbonTM Freedom Stentless Aortenklappe untersucht. Das mittlere Lebensalter betrug 64 +/- 17 Jahre. Präoperativ litten fünf Patienten an einer isolierten Aortenklappenstenose, drei Patienten an einer isolierten Aortenklappeninsuffizienz, ein Patient wies ein kombiniertes Aortenvitium auf. Drei Patienten hatten zusätzlich eine Mitralklappeninsuffizienz, 14 Patienten eine koronare Herzkrankheit und ein Patient eine kongenitale Aortenisthmusstenose. Bei drei Patienten bestand eine akute Aortenklappenendokarditis. 18 Patienten wurden als Hoch-Risiko-Patienten (EuroSCORE 9 +/- 2) klassifiziert. Die mittlere linksventrikuläre Auswurfsfraktion betrug 52.5 +/- 15.0%. Ergebnisse: Alle implantierten Klappenprothesen wurden, bezogen auf die intraoperative Anulusausmessung, um 2mm grösser gewählt. 16 Patienten erhielten isolierte Klappenersatzoperationen. Als Zusatzeingriffe wurden drei Mitralklappenrekonstruktionen, 12 aorto-koronare Bypass-Operationen und eine Resektion einer Aortenisthmusstenose in Kombination mit einem VSD-Verschluss durchgeführt. Drei Eingriffe waren Re-Operationen. Die postoperative Früh-Mortalität war 6.4% (zwei Hoch-Risiko-Patienten). Beide Todesfälle waren nicht klappenbedingt. Vier Patienten entwickelten postoperativ ein Low-Output-Syndrom und erhielten eine intra-aortale Ballon-Pumpe. Die sechs Monate postoperativ durchgeführte Echokardiographie erbrachte tiefe transvalvuläre Mean- und Peak-Gradienten (9.6 +/- 4.4 bzw. 20.6 +/- 5.9mmHg) sowie eine signifikante Regression der linksventrikulären Hypertrophie(linksventrikulärer Massenindex 126.5 +/- 27.3 vs. 189.6 +/- 45.3g/m2, p = 0.0313) und eine Verbesserung der systolischen Auswurfsfraktion (58 +/- 9.8 vs. 52.5 +/- 15.0%, p = 0.9749). Schlussfolgerungen: Die Sorin PericarbonTM Freedom Stentless Aortenklappe zeigte eine hervorragende hemodynamische Funktion, die nach sechs Monaten durch tiefe transvalvulären Gradienten, Regression der linksventrikulären Hypertrophie sowie Anstieg der systolischen Auswurfsfraktion charakterisiert ist. Aussagen bezüglich Lebensdauer und Abnützung des biologischen Gewebes können erst nach Durchführung von Langzeit-Untersuchungen erhoben werden.

Association of ABO histo-blood group B allele with myocardial infarction

To investigate a possible association of ABO blood group alleles with myocardial infarction, a case-control study comprising 177 patients (median age 57.0 years; range 32-72 years) and 89 controls was performed. The distributions of the ABO blood-genotype O1, O2, A1, A2 and B alleles were assessed by analysis of genomic DNA, using the sequence-specific primer-polymerase chain reaction (PCR-SSP) technique to investigate exons VI and VII on chromosome 9. The prevalence of the B allele was 2.5 times higher amongst patients with a history of myocardial infarction than amongst controls (16.3 vs. 6.7%; P = 0.034, Fisher's exact test). There was an association between patients carrying the B allele and myocardial infarction, with an odds ratio (OR) of 2.7 (95% confidence interval 1.1-6.8). The B allele remained an independent risk factor for myocardial infarction (P = 0.038) when classical risk factors were adjusted for by unconditional logistic regression. In conclusion, the ABO blood group B allele was found to be an independent risk factor for myocardial infarction.

Aprotinin reduces blood loss in off-pump coronary artery bypass (OPCAB) surgery

OBJECTIVE

Effects of aprotinin in off-pump coronary artery bypass (OPCAB) surgery have not yet been described. This study analyses hemostasiologic changes and potential benefit in OPCAB patients treated with aprotinin.

METHODS

In a prospective, double-blind, randomized study 47 patients undergoing OPCAB surgery were investigated. Patients received either aprotinin (2 x 10(6) KIU loading dose and 0.5 x 10(6) KIU/h during surgery, n=22) or saline solution (control, n=25). Activated clotting time was adjusted to a target of 250 s intraoperatively. Blood samples were taken up to 18h postoperatively: complete hematologic and hemostasiologic parameters including fibrinopeptide A (FPA) and D-dimer in a subgroup of 31 patients were analyzed. Blood loss, blood transfusion and other clinical data were collected.

RESULTS

Both groups showed comparable demographic and intraoperative variables. Forty-one (87%) patients of the whole study group received aspirin within 7 days prior to surgery. Number of grafts per patient were comparable (2.9+/-1.0 [mean+/-SD] in the aprotinin group and 2.8+/-1.2 in control, P=0.83). Blood loss during the first 18 h in intensive care unit was significantly reduced in patients treated with aprotinin (median [25th-75th percentiles]: 500 [395-755] ml vs. 930 [800-1170] ml, P<0.001). Postoperatively only two patients (10%) in the aprotinin group received packed red blood cells, whereas eight (35%) in the control group (P=0.07). Perioperatively FPA levels reflecting thrombin generation were elevated in both groups. The increase in D-dimer levels after surgery was significantly inhibited in the aprotinin group (P<0.001). Early clinical outcome was similar in both groups.

CONCLUSIONS

Aprotinin significantly reduces blood loss in patients undergoing OPCAB surgery. Inhibition of enhanced fibrinolysis can be observed. FPA generation during and after OPCAB surgery seems not to be influenced by aprotinin.