Theodosios Dosios

Effect of impaired vasa vasorum flow on the structure and mechanics of the thoracic aorta: implications for the pathogenesis of aortic dissection

OBJECTIVE To investigate the alterations of structure and mechanical properties of the aortic wall, resulting from impairment of vasa vasorum flow. METHODS Eight healthy Landrace pigs were subjected to interruption of vasa vasorum flow to the upper segment of their descending thoracic aorta. Under sterile conditions, the periaortic tissue was excised and the contiguous intercostal arteries were ligated. Ten sham-operated pigs were used as controls. Fifteen days postoperatively, the animals were sacrificed and their upper descending thoracic aortas were removed. Histology, and collagen and elastin content determination by image analysis technique were performed. Mechanical analysis of aortic strips was carried out with a uniaxial tension device and stress-strain curves were obtained. RESULTS In contrast to normal aortic walls of the control group, histology of the avascular aortas revealed severe ischemic necrosis of the outer media along with abnormal straightening of the elastin and collagen fibers, without significant collagen and elastin content changes. The borderline between the outer ischemic and inner non-ischemic media was sharp, and an outset of dissection was observed at this point. Mechanical analysis showed that at the same level of strain, the ischemic aorta was significantly stiffer at both low (P=0.03) and high strains (P=0. 003). CONCLUSIONS Impairment of blood supply to the thoracic aorta leads to abnormal morphology of elastin and collagen fibers of the outer media, resulting in increased aortic stiffness under a wide range of stresses. In the clinical setting, decreased vasa vasorum flow, reportedly occurring in arterial hypertension, may increase the stiffness of the outer media of the thoracic aorta and produce interlaminar shear stresses, contributing to the development of aortic dissection.

Surgical Treatment for Lung Hydatid Disease

Abstract. Lung is the second most common site for hydatid disease after the liver. The aim of this study is to present the clinical symptomatology, diagnostic evaluation, and surgical techniques for the treatment of lung hydatid disease. During the last 25 years, 42 patients with lung hydatid cysts were treated surgically in our department. In four patients there were cysts in the liver and in one case in the spleen. The cysts were located in the right lung in 16 patients (38%), in the left lung in 23 patients (54.8%), and in both lungs in 3 patients (7.14%). Eighteen patients (42.9%) presented with complications: suppuration in one patient (2.4%), rupture to the bronchial tree in 16 patients (38%), and pneumothorax in one patient (2.4%). Diagnosis was established preoperatively in all cases; chest radiography and computed tomography were most helpful for diagnosis. Forty-six operations were performed in 42 patients; three patients with bilateral cysts underwent staged thoracotomies, and one patient was reoperated for recurrent disease. All cases were managed surgically, with several types of radical (34 cases) or conservative (12 cases) procedures. Radical procedures were lobectomy and rarely pneumonectomy, which were used more often during the first half of the study period. Cystectomy with capitonnage, the most commonly performed conservative procedure, was mainly used during the second half of the study period. Postoperative morbidity was 15.2% and the 30-day mortality rate was 0%. In one case there was postoperative hemorrhage that required reexploration. The median hospital stay for uncomplicated cases was 12 days and for complicated cases 21 days. In conclusion, pulmonary hydatidosis often presents with complications requiring emergency surgery. A lung-conserving operation is the treatment of choice for lung hydatid disease and offers a good surgical outcome with a minimal recurrence rate.

p53 and bcl-2 protein expression in non-small-cell lung carcinoma

The diagnostic significance of p53 and bcl‐2 proteins in epithelial non–small‐cell lung cancers was examined, and the relationship between these proteins expression and other disease parameters, including stage of the disease and tumor differentiation, were studied.

Post-Vagotomy Mechanical Characteristics and Structure of the Thoracic Aortic Wall

This study assessed the long-term effect of vagotomy on the structure and passive mechanical characteristics of the thoracic aorta under a wide range of stresses in vitro. Eight healthy Landrace pigs underwent bilateral vagotomy distal to the origin of the recurrent laryngeal nerve, and 10 pigs were sham-operated. Three months post-surgery, the aorta was excised and specimens from the ascending aorta, arch, and descending thoracic aorta were subjected to histomorphometrical evaluation and uniaxial tensile-testing until failure. Elastic modulus-stress data were plotted and submitted to regression analysis. Structural remodeling after vagotomy was characterized as vascular growth in the ascending aorta and arch, and as thinning in the descending thoracic aorta. In the aortic segments of vagotomized animals, the area density of elastin and collagen was increased, but smooth muscle density was decreased. Similar differences in regression parameters and failure strength between groups were found in all aortic segments, indicating that the vessel wall was stiffer and stronger in vagotomized animals. In the clinical setting, disease states or drugs blocking the regulatory role of the vagi nerves on the aortic wall may have undesirable consequences on the mechanical performance of the thoracic aorta, and therefore on hemodynamic homeostasis.

Topographic anatomy of bronchial arteries in the pig: a corrosion cast study

The anatomy of porcine bronchial circulation has not been fully described. The purpose of this study was to investigate the extrapulmonary topographic anatomy of bronchial arteries in pig. Ten pigs weighing 15–25 kg were studied. Between one and four bronchial arteries were found in each pig. The bronchoesophageal artery (BEA), tracheobronchial artery (TBA), inferior bronchial artery (IBA) and accessory bronchial artery (ABA) were present in 10/10, 8/10, 6/10 and 2/10 animals, respectively. The trunk of BEA had a diameter of about 3 mm, a length of 1–7 mm, and originated from the anterior and medial aspect of the descending thoracic aorta at the level between the 2nd and 4th thoracic vertebrae (T2–T4) in all animals. The extrapulmonary topographic anatomy of bronchial arteries in pigs exhibits similarities to that of humans. BEA is the main blood supplier of the porcine tracheobronchial tree with a relatively constant location of origin and a sufficient size for anastomosis. These characteristics render BEA the ideal vessel for bronchial revascularization in pigs.

Evaporative water loss of adult surgical patients in Greece

Abstract Daily evaporative water loss was studied in seventy-two adult surgical patients in Greece. It was found to average 1,480 ml in preoperative patients and 1,751 ml in postoperative ones. It is concluded that the daily amount of water given to surgical patients for replacement of evaporative water loss in temperate climates should be 1,500 to 2,000 ml.

An alternative approach for the surgical management of hydatid disease of the liver.

Abstract. Hydatid disease of the liver still remains a serious medical problem. As a result of increased travelling and immigration, it has also appeared in previously unaffected countries and is now well manifested in countries where the medical personnel lack the experience to treat this problem. We report an alternative method for the surgical management of hydatid disease of the liver, especially that located over the right superior-posterior aspect of the liver. Through a lateral right thoracotomy, we have a better exposure of the cyst and by using the right hemidiaphragm we achieve the same beneficial effect as omentoplasty does.

The Mechanical Performance and Histomorphological Structure of the Descending Aorta in Hyperthyroidism

Thyroid hormones decrease systemic vascular resistance by directly affecting vascular smooth muscle relaxation. There is limited literature about their effect on the mechanical performance of the aortic wall. Therefore, the authors determined the influence of hyperthyroidism on the mechanical properties and histomorphological structure of the descending thoracic aorta in rats. Severe hyperthyroidism was induced in 20 male Wistar rats by administering L-thyroxine (T4) in their drinking water for 8 weeks; age-matched normal euthyroid rats acted as controls. Animals were sacrificed, and the mechanical and histomorphometrical characteristics of the descending thoracic aorta were studied. The aortic wall of hyperthyroid rats was stiffer than that of euthyroid animals at the upper physiologic levels of stress or strain (p < 0.05) but less stiff at the lower physiologic and lower levels (p < 0.05). The aorta of hyperthyroid animals compared with that of euthyroid ones showed an increase of the internal and external diameters (p < 0.05), the media area (p < 0.05), the number of smooth muscle cell nuclei (p < 0.05), and the collagen density (p < 0.05) and a decrease in the elastin laminae thickness (p < 0.001) and elastin density (p < 0.001). In hyperthyroid rats, the aortic wall was stiffer at the upper physiologic and higher levels of stress and strain. These changes correlated with microstructural changes of the aortic wall. The coexistence of hyperthyroidism with disease states or clinical conditions that predispose to increased arterial pressure may be associated with increased arterial stiffness and have undesirable consequences on the mechanical performance of the thoracic aorta and hemodynamic homeostasis. These changes could lead to an increased risk for developing vascular complications.

Myoplasty versus omentoplasty in the surgical treatment of hydatidosis of the liver dome

Background and aimsEven though surgery is the mainstay in the management of hydatid disease of the liver, controversies still exist about the preferred operating technique. This study was conducted to evaluate myoplasty versus omentoplasty for the surgical treatment of hepatic dome hydatidosis.Patients and methodsSixty-two patients with a hydatid cyst located over the right superior–posterior part of the liver or a cyst adherent to the right hemidiaphragm were classified into two groups according to the type of surgical approach. Group A comprised 50 patients who had undergone thoracoabdominal, right subcostal, or right paramedian incision. Group B comprised 12 patients who had undergone posterior–lateral thoracotomy. Twenty-four patients with a right thoracoabdominal incision underwent partial excision of the cyst with omentoplasty (18 patients), external drainage (four patients), and marsupialization (two patients).ResultsTwenty-six patients with a right subcostal or paramedian incision underwent partial resection of the cyst with omentoplasty (15 patients), external drainage (eight patients), and combination of procedures (three patients). Twelve patients that had undergone a right thoracotomy underwent partial excision of the cyst wall with myoplasty of the right hemidiaphragm. Surgical approaches such as thoracoabdominal, right subcostal, or paramedian incision were associated with higher morbidity rate than thoracotomy alone (P<0.03). In addition, patients with myoplasty of the right hemidiaphragm were associated with a lower morbidity rate than those with omentoplasty (P<0.02). Five patients had recurrent disease and were reoperated upon. Partial cystectomy and myoplasty of the right hemidiaphragm was performed with excellent results.ConclusionsThese results suggest that a thoracic approach, with myoplasty of the right hemidiaphragm and high-vacuum drainage, might produce low complication and recurrence rates and the best clinical results. Consequently, it is a promising procedure that requires more application and evaluation.