M. V. Inberg

Oxygen Transport to Tissue under Normovolemic Moderate and Extreme Hemodilution during Coronary Bypass Operation

Oxygen transport to tissue was studied in 12 patients undergoing coronary bypass operation under normovolemic moderate and extreme hemodilution. Normovolemic moderate hemodilution (15 ml per kilogram of body weight), carried out immediately after induction of anesthesia, decreased the mean hematocrit from 0.43 to 0.33. Simultaneously, the cardiac index and the left ventricular filling pressure increased slightly but the systemic oxygen transport was reduced by 20%. The subcutaneous tissue oxygen tension (PO2) was approximately 40 mm Hg after induction of anesthesia and underwent a transient increase during moderate hemodilution. During cardiopulmonary bypass and extreme hemodilution, the mean hematocrit declined to 0.16. Concurrently, the mean tissue PO2 fell sharply and reached a minimum of 14 mm Hg at deepest hypothermia. After decannulation and reinfusion of autologous blood, the PO2 rose to 30 mm Hg. In general, total-body oxygen consumption changed along with tissue PO2. Blood lactate concentration underwent a clear increase in the early phase of extracorporeal circulation and remained rather stationary thereafter. No perioperative myocardial infarctions were encountered, and each patient made an uneventful recovery.

Total and proximal gastrectomy in the treatment of gastric carcinoma: A series of 305 cases

A total of 305 total or proximal gastrectomies for gastric carcinoma were performed in 291 patients. Of the tumors 51.5% were of the intestinal-type and 35.7% were of the diffuse-type of carcinoma. Proximal gastrectomy was performed in 68 patients, total gastrectomy in 230, and anastomotic resection in 7. In 25 patients a reresection for recurrent carcinoma was performed. After total gastrectomy the main reconstructive procedures were end-to-side esophago-jejunostomy and Roux-en-Y esophagojejunostomy. The hospital mortality rate was 13.4%. The main causes of death were anastomotic leakage and pulmonary embolism. The incidence of leakage was 10.8% and the complication proved fatal in 36.4% of the patients who developed it. After Roux-en-Y reconstruction only 8% of the patients with leakage died. After curative operations 27% of the patients survived for over 5 years (relative survival rate of 33%). The 5-year survival rates for the intestinal-type and diffusetype of carcinoma were similar, but the 10-year survival rate for intestinal-type of carcinoma was significantly better. In our view a relatively high mortality rate after total or proximal gastrectomy has to be accepted when older patients are concerned, and when no other curative procedure is possible on account of the site and extent of invasion of the tumor. However, in cases where radical resection can be achieved by means of subtotal gastrectomy, this method is best. At present, in cases of the diffuse-type of carcinoma of the corpus, we perform a total gastrectomy instead of subtotal gastrectomy. In the small series of reresections the results were encouraging.

Composite graft in annulo-aortic ectasia : Nineteen years' experience without graft inclusion

OBJECTIVE The original Bentall procedure for the surgery of annulo-aortic ectasia (AAE) includes the risk of leakage and pseudo-aneurysm formation in the coronary anastomosis. To avoid the complications mentioned above we have used the open technique without the graft inclusion. In this study we evaluate our early and late results. MATERIAL AND METHODS One hundred consecutive patients with annuloaortic ectasia underwent surgical repair with composite graft between December 1975 and February 1994. In all cases the aneurysmal tissue was radically resected and the origins of the coronary arteries were directly reimplanted to the tube prosthesis. No wrapping was used. Twenty-two patients met the clinical criteria of Marfan syndrome. Thirteen of the patients underwent an emergency operation, because of a rupture of aneurysm in 2 cases and an acute dissection in 11 cases. Additional procedures were performed in 16 patients: mitral valve replacement in 2, coronary artery bypass grafting in 12 patients and in 2 cases the tube prosthesis included aortic arch, too. RESULTS The overall hospital mortality was 3.0% (3/100). In the elective group there was one hospital death (1/87; 1.1%). In the emergency group two patients died in the operation room (2/13; 16.7%). There have been 13 late deaths among the 97 hospital survivors (13.4%). Four of the late deaths were surgery related. Routine control angiography was performed in all patients 6 months after surgery. Sixty patients who had lived at least 3 years after surgery were called to reangiography and 53 of them came. No pseudo-aneurysm or leakage at distal anastomosis or coronary anastomosis could be seen. A slight dilatation of one or both coronary origins was observed on 15 patients; 9 of whom had Marfan syndrome. CONCLUSIONS The open technique is simple and can be used in all anatomical variations of the annulo-aortic ectasia. The early and late results are at least comparable with those achieved by other techniques.

Use of Activated Clotting Time to Monitor Anticoagulation During Cardiac Surgery

The use of a fixed dosage schedule was compared with the use of activated clotting time (ACT) for monitoring heparin anticoagulation and its neutralization during and after extracorporeal circulation in patients undergoing coronary artery bypass grafting. Use of ACT resulted in a statistically significant decrease in heparin and protamine dosages and statistically significant reductions in postoperative blood loss and blood transfusion needs. Postoperative levels of blood hemoglobin concentration were significantly higher and the activated partial thromboplastin time was significantly shorter with ACT monitoring than with use of a fixed dosage schedule. The results confirmed the superiority of the ACT method for monitoring anticoagulation during cardiac surgery.

Desmosines in aneurysms of the ascending aorta (annulo-aortic ectasia)

Amino acid chromatography was used for determination of the elastin-specific amino acids desmosine and isodesmosine in acid hydrolyzates of intima-medial samples taken intraoperatively from aneurysms of human ascending aorta. Elastin concentration of the specimens was also estimated by hot alkali extraction followed by nitrogen determination of the extracted material and the insoluble residue. All patients studied had annulo-aortic ectasia i.e., dilatation of the aortic annulus and the ascending aorta. Two patients with the Marfan syndrome had low aortic elastin concentration determined by both methods. A third Marfan syndrome patient, youngest of the three, also had a slightly reduced concentration of elastin in the aorta. Aortic samples were studied from five patients who did not have the classical Marfan syndrome. Two patients of those five had decreased aortic elastin concentration. The change in elastin concentration was accompanied by high hydroxyproline/proline or hydroxylysine/lysine ratios which indicates that the proteins of the aneurysmatic aortic wall contained more collagen than the proteins of the control aortic wall. These findings point to a change in the structure or metabolism of elastin in the aortic wall in the Marfan syndrome and at least in some other patients with annulo-aortic ectasia.

Early Results and Complications of Coronary Artery Bypass Surgery: A Consecutive Series of 441 Patients

The mortality rate and early complications of coronary artery bypass surgery were assessed for the first 441 consecutive patients operated on at Turku University Hospital. The overall hospital mortality rate was 2.5%. Perioperative myocardial infarction (PMI) accounted for more than half of the deaths, cerebral thromboembolism and sudden coronary death each for one-fifth and left ventricular failure for one-tenth. Postoperative complications occurred in 17.7% of the patients. Bleeding and postpericardiotomy syndrome were the most common complications (in 5.2 and 3.6% of the patients). Sternal resuture was needed in 3.2% of the patients, and PMI occurred in 2.9%. PMI had a 46% mortality rate, with two-thirds of the deaths occurring in the operating theatre. Only PMI reached statistical significance as sole cause of death. Mode of myocardial protection, completeness of revascularization and severity of coronary disease did not influence the PMI rate. Graft patency overall was 92.8% on average 3 months after surgery. The respective patency rates for internal mammary artery grafts and vein grafts were 90.3 and 92.9%.

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.

Management of Instrumental and Spontaneous (Atraumatic) Perforations of the Oesophagus

Twenty-one patients with perforation of the oesophagus were diagnosed and treated at the University Central Hospital of Turku in 1960-1969. Fourteen of them were instrumental and seven spontaneous perforations. In the cases of instrumental perforation the rupture generally occurred in connection with dilatation of lye stricture. In instrumental perforations the diagnosis was mostly delayed and treatment conservative. The mortality rate was 14% (2/14). In perforations caused by lye stricture conservative therapy led to a good result for the fixation of the environment and adhesions limited the spread of a mediastinal infection. In contrast, radical surgery should be the aim in other perforations, especially cases with residual distal obstruction. Two of the seven patients with spontaneous perforation died. Our results substantiate the view that early closure of spontaneous perforation should be aimed at. Although two patients were cured with pleural canalization alone, another two patients treated by the s...

Prosthetic Valve Endocarditis

Prosthetic valve endocarditis is an infrequent but serious complication of valve surgery. It occurred in 25 (3.2%) of 772 patients who received aortic, mitral or double valve replacement in 1971-1987. The total follow-up time was 3,976 patient years, giving an incidence of 0.63/100 patient years. Staphylococci were the most common of the cultured organisms in early and late infections-60% and 64%, respectively. The endocarditis was disclosed at autopsy in two cases. Treatment was antibiotics alone in 11 cases, and surgery was required in 12, the indication always being congestive heart failure. C-reactive protein level fell more rapidly than erythrocyte sedimentation rate in response to antibiotic or surgical management. The mortality rate was 73% in the antibiotic group and 33% in the surgical group. The findings demonstrated that an infected valve prosthesis should be replaced without delay if complications develop.

Myocardial oxygen balance during hemodilution in patients undergoing coronary artery bypass grafting.

The myocardial (arterial-coronary sinus) balance of oxygen and lactate was studied before a cardiopulmonary bypass and during the first 5 min of a normothermic bypass in two patient groups undergoing coronary revascularization for multiple coronary artery disease. The hemodilution (HD) group was hemodiluted before the bypass with dextran 70 (15 ml/kg; resulting mean hematocrit 32%) and further at the beginning of the bypass due to nonhemic priming of the oxygenator (mean hematocrit 15%). The control (C) group was not diluted before the bypass, and four units of red blood cells were included in the oxygenator priming (mean hematocrit 27% after the beginning of the bypass). The preoperative dilution produced a decline in the coronary sinus blood oxygen tension and oxygen saturation, but no change in the arterial-coronary sinus lactate balance. After the first 5 min of the bypass, the heart produced lactate in both the HD group and the C group, but the lactate production was more pronounced in the HD group. At the same time, the coronary sinus blood oxygen saturation was lower in the HD group than in the C group. Hypotension frequently accompanied the beginning of the bypass in both groups. It is concluded that the hemodilution to a hematocrit level of 32% in patients undergoing coronary revascularization for multiple stable coronary artery disease produces compensatory changes in myocardial oxygen extraction, but no changes of a generalized ischemia can be demonstrated. The hemodilution to a hematocrit level of 15% produces myocardial ischemia in patients with a normothermic unloaded heart, adding to the effect of hypotension at the beginning of the bypass.