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Gelatin-resorcin-formaldehyde-glutaraldehyde (GRF) biologic glue is an available adjunct to repair acute ascending aortic dissections. Permanent complete heart block complicated the operative repair of 2 of 6 patients. The pathophysiology of heart block resulting from either the acute dissecting process or the technique of applying GRF glue is discussed.

We read with great interest the state-of-the-art article by Brochhausen et al. regarding the pectus excavatum and we agree with the authors that its surgical treatment by various techniques can improve long term results in terms of cosmetics and potential cardiorespiratory function [1, 2]. Therefore, we would like to comment on the surgical approach. Criteria for the surgical treatment of pectus excavatum, according to Kelly and colleagues, are related to the severity of symptoms and anatomical deformity followed by two or more criteria such as computerized tomography-index (or Haller-index) greater than 3.25, signs of cardiac and or pulmonary compression on computerized tomography or echocardiography, mitral valve prolapse, arrhythmias and restrictive lung disease [2]. The minimally invasive Nuss procedure is safe [3]. In the relatively recent (study period 1987-2006) review of 18 series, reporting on 1949 children with a mean age of 10.6 years, there was no mortality and the incidence of morbidity was 15.4%. The average operative time was 68 minutes (from 28 to 200 min) and the average hospitalization was 5.5 days (from 2 to 27 days) [3]. The most common reported complications were bar related events (5.7%), pneumothorax (3.5%), wound infections (2.2%) and pleuropulmonary complications (2%) such as pleural effusions, atelectasis, and pneumonia [3]. In addition to common complications, Swanson and Colombani have reported on three cases within a period of 1 year with reactive pectus carinatum in patients who underwent pectus excavatum repair (two patients underwent minimally invasive Nuss procedure and one patient the Ravitch procedure). It should be noted that the pectus carinatum resolved in one patient who had an early bar removal. The other two patients required surgical correction at 3 and 6 years after the first surgical intervention .The need for close follow up for the early identification and successful treatment of this complication, particularly in the first six postoperative months, is of paramount importance [4]. In addition, Willekes et al. in their retrospective study of a 26-year experience with pectus deformities repair in 120 children with a mean age of 8.4 years (from 3 to 21 years) found that the long-term results of pectus deformities repair (excavatum and carinatum) through a vertical midline approach are excellent and the outcome with a temporary sternal bar is superior to that without a bar (p = 0.004). Nine patients had an associated congenital heart defect and underwent successfully simultaneous pectus excavatum and intracardiac repair with no additional morbidity [5]. In conclusion, surgical repair of pectus excavatum by various techniques has good long term results. However, a multidisciplinary approach and assessment of these patients on an individual basis is very important when considering the timing and type of procedure. A combined simultaneous approach in dealing with concomitant congenital or acquired heart conditions can be performed safely by an experienced team [2, 5].

The vascular endothelium is a complex modulator of a variety of biological systems and may well be the key to definitive success in the treatment of cardiovascular disorders. Surgically-induced endothelial injury may occur preoperatively during cardiac catheterization and intraoperatively from mechanical manipulation, ischemia, hypothermia, and exposure to cardioplegic solutions. The normal endothelium is antithrombogenic and yet promotes platelet aggregation and coagulation if injured. Vasospasm, occlusive intimal hyperplasia, and accelerated arteriosclerosis can also all occur as a result of endothelial injury. Furthermore, endothelial injury is harmful even in the absence of disruption of its monolayer integrity. Thus, preservation of the endothelium should be an additional objective for all cardiovascular surgeons. Synthetic vascular grafts, cardiac valves, and artificial ventricles do not spontaneously endothelialize and thus usually require some form of anticoagulation to maintain patency. Hence, endothelialization of prosthetic implants became an attractive concept. A number of different methods of obtaining an endothelial lining of prosthetic material has since been developed; these include facilitated endothelial cell migration, and endothelial cell seeding by using either venous or microvascular endothelial cells. Manipulating the endothelium might well provide the next major advancement for therapeutic and preventive measures for cardiovascular disease.

Endothelial cell damage caused by myocardial cardioplegic solutions (Bretschneider HTK and St. Thomas' Hospital No. 2) or renal and hepatic cold storage solutions (modified Collins and University of Wisconsin solution) was assessed in monolayer cultures of adult human venous endothelial cells at 4 degrees to 10 degrees C with phase-contrast microscopy. St. Thomas' Hospital solution caused the cells to contract, resulting in disruption of monolayer integrity and opening of intercellular gaps, and resulted in a 24-hour postexposure survival of 51.0% +/- 2.4%. Bretschneider HTK solution altered cellular morphology less and produced the best postexposure survival (80.2% +/- 2.6%; p less than 0.001). Although morphology was altered the least with University of Wisconsin solution, postexposure survival with this solution, which was similar to that with modified Collins solution, was superior to that with St. Thomas' (p less than 0.01) but inferior to that with Bretschneider HTK (p less than 0.05). The superior protection provided by Bretschneider HTK was due to its additives histidine, tryptophan, and KH-2-oxygluterate (p less than 0.005), and to its low chloride content (p less than 0.005). Furthermore, modifying St. Thomas' solution by decreasing its chloride content improved cell survival to 71.2% +/- 2.3% (p less than 0.001). Normothermic (37 degrees C) exposure to Bretschneider HTK, modified Collins, and University of Wisconsin solution was cytotoxic, whereas normothermic exposure to St. Thomas' cardioplegia was not. In conclusion, the preservation solution that is the least harmful to endothelial cells at hypothermia is Bretschneider HTK cardioplegic solution.

In light of the rapidly increasing use of percutaneous transluminal coronary angioplasty, valvular balloon dilatation has recently been recommended in paediatric and adult cases as an alternative to various classical operative techniques (1, 2). Interventional cardiology seems to avoid traumatic surgery, and valvular balloon dilatation might have a lower mortality and morbidity rate, and repeat dilatations are thought to be easier to perform. In Table 1, an attempt is made to compare these postulated benefits with those of “classic” cardiac surgical techniques which, in general, provide well established and documented results.