Retrograde cardioplegia in CABG: is it really useful? The microcirculation and a capillary unit model.

Most surgeons, ourselves including, use retrograde cardioplegia in numerable operations in cardiac surgery. It is believed to be not only supplementary to antegrade, but also a unique alternative in special complicated cases. Regarding CABGs (coronary artery bypass grafts), many authors advocate its routine use together with antegrade, while others do not suggest it for standard practice. The existing disagreement on this special item is consequential to the different results among various protocols which have studied the effect of antegrade and retrograde perfusion. In these studies, fundamental variations in design, materials, and methods have resulted in an inability to compare results. Additionally, most of the published protocols studying cardioplegic arrest offer only a gross estimation of the microcirculatory perfusion, which is the basis of myocardial protection. Our present review is an attempt to elucidate the differences, explain the necessity of comparing retrograde cardioplegia alone with antegrade in CABGs for the reproduction of safe results, clarify the role of Thebesian veins and venovenous connections during retroperfusion, consider the critical anatomic differences between human hearts and those of animals which may result in serious study bias, and, finally, offer an explanation of what may really be going on in the microcirculation during antegrade and retrograde perfusion using a human capillary model.

A huge posteromedial mediastinal cyst complicated with vertebral dislodgment.

BACKGROUND: Mediastinal cysts compromise almost 20% of all mediastinal masses with bronchogenic subtype accounting for 60% of all cystic lesions. Although compression of adjoining soft tissues is usual, spinal complications and neurological symptoms are outmost rare and tend to characterize almost exclusively the neuroenteric cysts. CASE PRESENTATION: A young patient with intermittent, dull pain in his back and free medical history presented in the orthopaedic department of our hospital. There, the initial clinical and radiologic evaluation revealed a mediastinal mass and the patient was referred to the thoracic surgery department for further exploration. The following computed tomography (CT) and magnetic resonance imaging (MRI) shown a huge mediastinal cyst compressing the T4-T6 vertebral bodies. The neurological symptoms of the patient were attributed to this specific pathology due to the complete agreement between the location of the cyst and the nervous rule area of the compressed thoracic vertebrae. Despite our strongly suggestions for surgery the patient denied any treatment. CONCLUSION: In controversy with the common faith that the spine plays the role of the natural barrier to the further expansion of cystic lesions, our case clearly indicates that, exceptionally, mediastinal cysts may cause severe vertebral complications. Therefore, early excision should be considered especially in young patients or where close follow up is uncertain.

Spontaneous rupture of the colon sigmoid following spontaneous recurrent pneumothorax in a patient with Marfan syndrome.

BACKGROUND: Spontaneous ruptures of the colon and rectum are very rare clinical entities and always require laparotomy. In such cases, despite meticulous exploration an underlying pathology cannot be revealed and most reports in the world literature relate spontaneous colon ruptures with unusual connective tissue disorders such as Marfan or Ehlers-Danlos syndrome. Connective tissue diseases affect the structure and the synthesis of elastin and type III collagen, resulting in various systemic disorders. Among the several pulmonary manifestations, spontaneous pneumothorax is observed in about 5% of patients expressing one of the above syndromes. CASE REPORT: In the following report we present a unique case of spontaneous rupture of the sigmoid colon secondary to spontaneous recurrent contralateral pneumothorax. CONCLUSIONS: The aim of this presentation is to raise the level of suspicion in every surgeon and gastroenterologist to include connective tissue disorders in their differential diagnosis in any case of spontaneous colon rupture and, if found, to follow further diagnostic procedures in anticipation of any other visceral complications.