Tapani Havia

Pancreatic Tissue Perfusion in Experimental Acute Pancreatitis

OBJECTIVE To investigate pancreatic tissue perfusion and oxygenation in severe and mild experimental acute pancreatitis in pigs. DESIGN Randomised controlled experiment. SETTING Animal laboratory, Finland. ANIMALS 24 domestic pigs weighing 21-27 kg. INTERVENTIONS 24 pigs were randomised into severe acute pancreatitis, mild acute pancreatitis and control groups (n = 8 in each). The pancreatic duct of eight anaesthetised and mechanically ventilated pigs was cannulated and taurocholic acid was infused into the pancreatic duct to induce severe acute pancreatitis. Eight animals received intraductally infused saline and developed mild acute pancreatitis. Eight pigs had their ducts cannulated alone, and served as controls. MAIN OUTCOME MEASURES Pancreatic tissue oxygenation, laser Doppler red cell flux, central haemodynamics. RESULTS Intraductally infused taurocholic acid rapidly induced macroscopically and histologically proven severe necrotising acute pancreatitis. Histological changes characterising mild acute pancreatitis were seen in animals after intraductal saline infusion. Pancreatic tissue oxygen tension decreased in the severe group and increased in the mild group during the six-hour study period. Laser Doppler red cell flux decreased in the severe group. Central haemodynamics, arterial blood gases, and acid base balances were stable throughout the study period in all groups. CONCLUSION The present model of severe acute pancreatitis significantly impairs pancreatic oxygenation in the early phase. In mild acute pancreatitis, pancreatic oxygenation increases.

Surgical treatment of aneurysms of the ascending aorta. With special reference to cystic medial necrosis of the aorta.

The clinical series comprised 14 patients with aneurysms of the ascending aorta. In the autopsy series, there were additionally 19 patients, who had died suddenly as a results of free perforation or dissection of the ascending aorta. In the clinical series, the cause of the aneurysmal formation was cystic medial necrosis in 10 patients, 8 of whom had severe aortic valve insufficiency. Twelve patients were operated on using extracorporeal circulation, Both the ascending aorta and aortic valve were replaced with prosthesis in 6 cases. Three patients underwent emergency surgery due to pericardial tamponade. All three died, despite a technically successful operation. One patient out of 9 electively operated upon died. A follow-up examination was carried out on the 5 surviving cystic medial necrosis patients. Aneurysms of the sinuses of Valsalva developed after supracoronary resection in 2 patients. The results showed that elective operations in the event of aneurysms of the ascending aorta can be carried out with an acceptably low mortality rate. However, after supracoronary resection, in cases of cystic medial necrosis, the risk of developing aneurysms of the proximal aortic remnant seems obvious. Therefore, in patients in whom the whole aortic root is involved, total removal of the ascending aorta and re-implantation of the coronary ostia into the prosthetic tube is preferable.

What happens to the Valtrac® anastomosis of the colon?

Late results after colonic anastomoses performed with the biofragmentable anastomosis ring (BAR; Valtrac®; Davis & Geck, Wayne, NJ) were evaluated in 30 patients who had undergone a left-sided colonic or rectosigmoid anastomosis a mean of 24.5 (range, 12–38) months earlier. Patients were asked about their late postoperative recovery and their bowel habits. A barium enema was performed, and then a flexible endoscopy was done, during which the anastomotic area was evaluated both in macroscopic terms and histologically. One of the patients had died, and three refused to participate in the investigation. Of the remaining 26 patients, one had been reoperated on 22 months after the primary sigmoid resection. The reason for reoperation was an anastomotic stricture. One of the patients was admitted to the hospital during the study and was operated on for reasons not related to the anastomosis. Twenty-four patients underwent the study scheme. All had recovered uneventfully. Sixteen anastomoses could not be identified radiologically and seven not even during endoscopy. Histologically, there was mild-to-moderate fibrosis and scarring in 17 anastomoses, and, in the seven that could not be identified, only normal colonic mucosa was found. The late results of BAR anastomoses are satisfying, and the rate of complications is acceptable.

Central haemodynamics in experimental acute pancreatitis

OBJECTIVE To investigate central haemodynamics in severe and mild acute pancreatitis in pigs. DESIGN Randomised controlled experiment. SETTING Animal laboratory, Finland. SUBJECTS 24 domestic pigs weighing 21-27 kg. INTERVENTIONS In 8 anaesthetised and mechanically ventilated pigs the pancreatic duct was cannulated and taurocholic acid was infused to induce severe acute pancreatitis. Eight animals received intraductal saline infusion and developed mild acute pancreatitis. Eight pigs were cannulated alone and served as controls. MAIN OUTCOME MEASURES Cardiac index, heart rate, mean arterial pressure, central venous pressure, mean pulmonary arterial pressure, pulmonary arterial occlusion pressure, haemoglobin, arterial blood gases and acid base balance. RESULTS Intraductally infused taurocholic acid rapidly induced severe necrotising acute pancreatitis as assessed both macroscopically and histologically. Histological changes of mild acute pancreatitis were seen in animals after intraductal saline infusion. Central haemodynamics, arterial blood gases, and acid base balances were stable throughout the study period in all groups. The main finding was haemoconcentration as indicated by the increase in arterial haemoglobin concentration in pigs with mild and severe acute pancreatitis. CONCLUSION Haemoconcentration precedes central haemodynamic alterations in experimental acute pancreatitis.

Management of Oesophageal Carcinoma: A Report of 267 Cases

A series of 267 patients with oesophageal carcinoma is presented. There were 151 women and 116 men; the mean age was 65 years. During the whole period 1960–1971 surgical excision was the treatment of choice. The overall operability was 45.2% and the re-sectability of the whole material 30.3%, but 66.9% of the cases were considered operable. Eighty-one patients were treated by surgical excision and anastomosis. The method of choice was one-stage oesophagectomy and oesophagogastrostomy. Altogether 87 patients received irradiation therapy alone. This group consisted of patients who were found inoperable at exploration or estimated to be unsuitable for radical surgery. In the group of 99 patients without active therapy, feeding gastrostomy or a Celestin tube was used in 43 cases.Early mortality rate after oesophageal resection was 18.5%; 13% during the last 6-year period. During this period one-third of the patients were more than 70 years of age. Anastomotic leakage was verified in five cases (6.2%), three o...

Catalytic activity of phospholipase A2 in blood plasma and pancreatic tissue perfusion in early experimental acute pancreatitis

Background: To investigate the sequence of changes in the catalytic activity of phospholipase A2 in plasma and pancreatic tissue perfusion and oxygenation in mild and severe acute pancreatitis in pigs. Methods: Twenty-four pigs were randomized into the groups of severe acute pancreatitis, mild acute pancreatitis, and controls. The pancreatic duct of eight anesthetized and mechanically ventilated pigs was cannulated, and taurocholic acid was infused into the pancreatic duct to induce severe acute pancreatitis. Eight animals received intraductal saline and developed mild acute pancreatitis. Eight pigs were cannulated only and served as controls. Results: Central hemodynamics, arterial blood gases, and acid-base balance were stable throughout the study period in all three groups. Pancreatic tissue oxygenation decreased in pigs with severe acute pancreatitis and increased in animals with mild acute pancreatitis. The catalytic activity of phospholipase A2 in plasma remained stable, and there was no difference between the groups. Similarly, C-reactive protein values remained within the normal range during the study period in all groups. Conclusion: Plasma phospholipase A2 levels do not react to the changes in pancreatic tissue perfusion in the early phase of mild and severe acute pancreatitis.

Does normothermia afford better conditions for myocardial oxygenation than hypothermia during artificial coronary perfusion? A clinical study of aortic valve replacement patients.

Myocardial oxygenation and lactate metabolism, changes in haemoglobin oxygen affinity and postoperative myocardial recovery were studied during normothermic (NCP) and hypothermic (HCP) coronary perfusion in association with aortic valve replacements. The P50 values were maintained at prebypass levels in the NCP-group, but were significantly lower in the HCP-group than in the NCP-group during and after bypass. This was reflected in a greater oxygen extraction from the haemoglobin by the myocardium only after bypass. During coronary perfusion, the arterial-coronary sinus oxygen content difference decreased by about 70% and the coronary sinus blood PO2 and oxygen saturation increased by about 60% and 80%, respectively. During rewarming after hypothermia in the HCP-group there was a marked lactate production by the myocardium in 3 out of 8 patients. After bypass the myocardial oxygen extraction was only slightly diminished as compared to the preoperative control in both groups. At this stage ne signs of defec...

Elevated Mid-Myocardial Oxygen Tension in the Fibrillating Heart During Cardiopulmonary Bypass

Mid-myocardial tissue oxygen tension was measured in the left ventricular wall of the hearts of ten dogs by means of a Silastic tonometer implanted earlier. During cardiopulmonary bypass, myocardial PO2 was significantly higher in a spontaneously fibrillating heart (5.4 +/- 0.9 kPa) than during the initial beating period (3.7 +/- 0.5 kPa) or after defibrillation (4.0 +/- 0.7 kPa). In general, there was a tendency towards increased myocardial blood flow, elevated oxygen uptake and reduced coronary sinus oxygen content during ventricular fibrillation, compared with the situation in the beating heart. Myocardial lactate extraction remained unchanged during the different phases of cardiopulmonary bypass. The increase in mid-myocardial oxygen tension during ventricular fibrillation was probably due to increased total myocardial blood flow and redistribution of regional myocardial circulation. In two additional dogs, ventricular fibrillation resulted in left ventricular distension and a simultaneous fall of myocardial oxygen tension, which indicates the necessity of left ventricular decompression suction in a fibrillating heart during cardiopulmonary bypass.

Parenchymal Gas Tensions in Canine Lung

Lung parenchymal oxygen and carbon dioxide tensions were measured in dogs by using chronically implanted Silastic tubes. The effects of pulmonary arterial ligation and bronchial occlusion on lung tissue gases were recorded. Prevention of venous return to the lung increased parenchymal oxygen tension markedly. Obstruction of airways and bronchial arteries resulted in a profound decrease in parenchymal oxygenation.