Ascending aorta replacement vs. total aortic arch replacement in the treatment of acute type A dissection: a meta-analysis

OBJECTIVE

Acute type A aortic dissection (ATAAD) is a severe, rapidly progressing disease which typically requires patients to undergo emergency surgical intervention. Despite advancements in surgical procedures, still, ATAAD remains a surgical emergency associated with high mortality. The aim of this systematic review and meta-analysis was to compare whether either ascending aorta replacement (AR) or total aortic arch replacement (TR) leads to improved short- and long-term clinical outcomes.

MATERIALS AND METHODS

A search of PubMed, Embase, Science Direct, Web of Science, SciELO, BIOSIS, and China National Knowledge Infrastructure (CNKI) databases were supplemented by searching through bibliographies of key articles. Thereafter, data on early and late prognostic factors were extracted. A systematic review and meta-analysis of 15 studies were performed to compare whether either AR or TR leads to a reduction in the risk of in-hospital and short-term mortality, postoperative complications, re-operation rate, and long-term mortality.

RESULTS

A total of 15 cohort studies (n = 2822 patients with ATAAD; AR with HA, partial arch = 1911, TR = 911) were deemed eligible and included in the meta-analysis. Compared with TR, AR led to a significantly lower risk of in-hospital mortality (RR = 0.77; 95% CI: 0.61-0.96), shorter cardiopulmonary bypass time (CPB, mean difference = -53.09; 95% CI: -56.68--49.50), circulatory arrest time (CA, mean difference = -8.09; 95% CI: -9.04-7.15), and antegrade cerebral perfusion (ACP, mean difference = -28.62; 95% CI: -30.23--27.00). Differences in the incidence rates of neurological dysfunctions and renal dialysis were not significant. The pooled rate of aortic re-operation was lower in TR group (AR 7.6% vs. TR 5.3%), albeit not significantly (risk ratio = 1.39; 95% CI: 0.94-2.07; p = 0.10).

CONCLUSIONS

These findings demonstrate that AR is associated with a lower early mortality rate and shorter operative times overall. Nevertheless, the incidence of postoperative complications in patients undergoing AR is comparable to that of patients undergoing TR. Further prospective follow-up data needs to be collected and analyzed to discern whether there are statistically significant differences in the risks of re-operation and long-term mortality between AR and TR procedures.

Thrombocytopenia in an animal model of malaria is associated with an increased caspase-mediated death of thrombocytes

Infection of mice with Plasmodium Berghei Anka (PbA) leads to a thrombocytopenia, due to a reduced platelet life span, eventually associated with a syndrome of severe or cerebral malaria (CM). Thrombocytopenia was associated with an increase in the number of microparticles (mcp) in plasma. More than >60% of these mcp were of platelet origin, as seen by staining with an anti-platelet antibody. The thrombocytopenia and the amount of mcp were decreased in mice treated with anti CD40L mAb, suggesting that CD40L is the main effector of the thrombocytopenia. Caspase-1, -3, -6, -8, -9 were activated in platelets from infected mice, as seen by the binding of labeled probes or the amount of pro-caspase-3. Treatment of infected mice with the caspases inhibitor ZVAD-fmk decreased the number of mcp and the thrombocytopenia, showing that platelet caspases are responsible for platelet fragmentation. In addition, the caspase inhibitor also caused a decrease in the mortality associated with CM, indicating a critical role of caspases in the expression of CM.

Hyperoxia increases leptin production: a mechanism mediated through endogenous elevation of corticosterone

Leptin, a cytokine involved in the regulation of food intake, has been reported to be decreased in lung diseases such as chronic obstructive pulmonary disease and cystic fibrosis and increased in critically ill patients with sepsis. We investigated the role of leptin during hyperoxia in mice, which results in alveolar edema, severe weight loss, and death within 3-4 days. In oxygen-breathing mice, serum leptin was increased six- to sevenfold and its mRNA was upregulated in white adipose tissue. Leptin elevation could not be attributed to changes in circulating tumor necrosis factor-alpha but was completely dependent on endogenous corticosterone elevation because adrenalectomized mice did not exhibit any increase in leptin levels. Using leptin-deficient mice and wild-type mice treated with anti-leptin antibody, we demonstrate that weight loss was leptin independent. Lung damage was moderately attenuated in leptin-deficient mice but was not modified by anti-leptin antibody or leptin administration, suggesting that leptin does not play an essential role in the direct and short-term effects of oxygen-induced injury.

Role of CD40-CVD40L in mouse severe malaria

We explored the role of CD40-CD40L (CD154) in the severe malaria elicited by Plasmodium berghei anka infection in mice. Mortality was >90% by day 8 after infection in +/+ mice, but markedly decreased in CD40-/- or in CD40L-/- mice, as well as in +/+ mice treated with anti-CD40L monoclonal antibody. Parasitemia was similar in the different conditions. Breakdown of the blood-brain barrier was evident in infected +/+, but not in CD40-/- mice. Thrombocytopenia was less severe in CD40-/- mice than in the +/+ controls. Sequestration of macrophages in brain venules and alveolar capillaries was reduced in CD40-/- or in CD40L-/- mice, whereas sequestration of parasitized red blood cells or polymorphonuclear leukocytes in alveolar capillaries was CD40-CD40L-independent. CD40 mRNA was increased in the brain and lung of infected mice whereas CD40L was increased in the lung. Tumor necrosis factor plasma levels were similarly increased in infected +/+ or CD40-/- mice. Expression of CD54 and its mRNA levels in the brain were moderately decreased in CD40-deficient mice. Thus the mortality associated with severe malaria requires CD40-CD40L interaction that contributes to the breakdown of the blood-brain barrier, macrophage sequestration, and platelet consumption.

Coexistence of tuberculous constrictive pericarditis and right atrial tuberculoma: a case report

Tuberculous constrictive pericarditis is a rare condition with a high mortality rate. The coexistence of constrictive pericarditis and intracardiac tuberculoma has not previously been reported. We report the case of a 65-year-old man presenting with left-side pleural effusion and signs of systemic venous congestion for 2 months. Echocardiography and computerized tomography showed a thickened pericardium and a mass in the right atrium. Pericardiectomy and excision of the right atrial mass were performed. Pathologic examination of the pericardium and the right atrial mass both revealed chronic granulomatous inflammation with acid-fast bacilli and confirmed the diagnosis of tuberculous constrictive pericarditis and right atrial tuberculoma. This case reminds us of the possibility of this type of rare combination of tuberculous constrictive pericarditis and intracardiac right atrial tuberculoma, and the need for complete imaging studies when such cases are encountered.

Application of pusher in mini-invasive patent ductus arteriosus ligation

The possibility of a residual shunt is a major drawback to current minimally invasive procedures for the treatment of patent ductus arteriosus (PDA). From April 1997 to October 1999, 30 patients (10 males, 20 females) underwent PDA ligation by a modified technique that uses a pusher for securing the ligate of PDA via posterolateral minithoracotomy at our hospital. No complication or mortality occurred. Postoperative echocardiography also revealed no residual shunt. In this article, we introduce this simple, safe procedure for PDA ligation.

Brachial plexus injury following coronary artery bypass surgery: a case report

Postoperative brachial plexus injury, often manifesting as a variety of upper extremity neuropathies, is a recognized and not uncommon complication following cardiac surgery that requires a median sternotomy. In general, the vast majority of its neurological symptoms are transient and need no treatment. Nevertheless, in very rare cases, the peripheral neuropathies will persist and cause disability. We treated a 67-year-old male patient complicated by permanent paresthesia and paralysis of the left upper extremity after an eventful coronary artery bypass surgery. The nerve conduction measurements and electromyography all revealed a C5 to T1 lesion. After carefully reviewing the surgical course and referring to the published literature, we tentatively concluded that compression or overstretching produced by wide and prolonged sternal separation of the brachial plexus was the most likely etiology. Asymmetrical traction of the sternal halves during internal mammary artery harvesting might also have contributed to this nerve injury. We surmised, therefore, that brachial plexus injury could be minimized by an exact median sternotomy, a lower position and the smallest possible opening for the sternal retractor, and the avoidance of constant and asymmetrical traction on the sternal halves.

Mitral valve replacement in the presence of massive posterior annular calcification

Replacement of the mitral valve in the presence of extensive calcification of the posterior annulus is a technical challenge. The heavily calcified annulus often results in difficulties of seating the prosthesis and later periprosthetic leakage. A radical calcium debridement may leave a friable and thin annulus that contributes to the risks of prosthesis dehiscence and ventricular perforation. To avoid technical difficulties and associated catastrophic complications, we devised a new technique of mitral valve replacement that allows a surgeon to implant a prosthesis securely. This technique involves inserting a larger single tilting disc mechanical valve (Medtronic Hall disc) with intra-atrial anchorage over the posterior sector of the calcified annulus, orienting the working (major) orifice of the mechanical valve anteriorly, and thereby tilting the lesser occluder segment of the disc upward into the atrium and away from the calcification in diastole. By utilizing this method, we have successfully performed mitral valve replacement in two patients who exhibited massive calcification of the posterior mitral annulus. Postoperative transeosophageal echocardiography showed excellent hemodynamic performance of the implanted valves. We therefore recommend this simple, safe, and time-saving procedure as a feasible method to deal with this surgical dilemma.

Endoscopic saphenous vein harvest decreases leg wound complication in coronary artery bypass grafting patients

BACKGROUND

Coronary artery bypass grafting (CABG) is the most common procedure performed in adult cardiovascular surgery. The most frequently used conduit is the greater saphenous vein. Using traditional methods, the complication rate of the leg is relatively high (up to 24%). To decrease the complication rate, we used the Endo-Path to harvest the greater saphenous vein.

METHODS AND RESULTS

From May 1997 through March 1999, a total of 135 patients received the CABG operation. We excluded the patients who died immediately postoperatively or had concomitant surgical procedures. Sixty patients received the endoscopic saphenous vein harvest procedure (group A), while another 59 patients (group B) did not. No important differences were noted between the two groups in respect to the number of distal anastomoses, length of harvested vein, total surgical time, and length of ICU stay. However, the leg wound complication rate decreased from 20.3% to 5.0% (p < 0.001).

CONCLUSIONS

Although the long-term patency rate needs time to be proven, the endoscopic greater saphenous vein harvest method is an attractive and effective method.

Keratinocyte growth factor protects alveolar epithelium and endothelium from oxygen-induced injury in mice

Keratinocyte growth factor (KGF) has been used successfully to prevent alveolar damage induced by oxygen exposure in rodents. However, this treatment was used intratracheally and before oxygen exposure, which limited its clinical application. In the present study, mice were treated with the recombinant human KGF intravenously before (days -2 and -1) or during (days 0 and +1) oxygen exposure. In both cases, lung damage was attenuated. KGF increased the number of cells incorporating bromodeoxyuridine (BrdU) in the septa and in bronchial epithelium of air-breathing mice but not of oxygen-exposed mice, indicating that the protective effect of KGF is not necessarily associated with proliferation. Oxygen-induced damage of alveolar epithelium and, unexpectedly, of endothelium was prevented by KGF treatment as seen by electron microscopy. We investigated the effect of KGF on different mechanisms known to be involved in oxygen toxicity. The induction of p53, Bax, and Bcl-x mRNAs during hyperoxia was to a large extent prevented by KGF. Surfactant proteins A and B mRNAs were not markedly modified by KGF. The anti-fibrinolytic activity observed in the alveoli during hyperoxia was to a large extent prevented by KGF, most probably by suppressing the expression of plasminogen activator inhibitor-1 (PAI-1) mRNA and protein. As PAI-1 -/- mice are more resistant to hyperoxia, KGF might act, at least in part, by decreasing the expression of this protease inhibitor and by restoring the fibrinolytic activity into the lungs.