Axel Henze

Management of Thrombo-Embolism after Aortic Valve Replacement with the Björk-Shiley Tilting Disc Valve: Medicamental Prevention with Dicumarol in Comparison with Dipyridamole—Acetylsalicylic Acid. Surgical Treatment of Prosthetic Thrombosis

Dicumarol anticoagulation poved very effective in the prevention of thromboembolic complications after aortic valve replacement with the Björk-Shiley tilting disc valve. We have, however, encountered six late deaths because of massive cerebral hemorrhage, which represent 3% of the patients who were maintained on dicumarol medication at that time. This unacceptable mortality prompted us to introduce two programmes, one without anticoagulation and another one with dipyridamole-acetylsalicylic acid. Furthermore, dicumarol was terminated in patients with haemorrhagic episodes, instable anticoagulation, pregnancy, and in those reguiring surgery. The results were disappointing, however, and the majority of the patients involved were therefore put on dicumarol medication. Eleven of the 64 consecutive patients taking dipyridamole - acetylsalicylic acid had thrombo-embolic episodes during a mean follow-up period of 9 months...

Ruptured Sinus of Valsalva Aneurysms

Ruptured aneurysms of the aortic sinuses of Valsalva have been a surgical rarity at the Karolinska Hospital. Only nine such cases were operated on over a 13-year period (1968-1971). All nine aneurysms were of congenital type. They originated in the right coronary or the non-coronary sinus and drained into the right ventricle or the right atrium. All five ventricular entries were combined with a VSD in the membranous septum. No patient was in critical condition, despite significant left-to-right shunt and reduced aortic diastolic pressure. Aortic root angiography conclusively demonstrated the rupture per se, but even complete invasive examination failed to reveal two VSDs which were detected at surgery. Coexistent cardiac defects (5 VSDs, one ASD and one infundibular pulmonic stricture) were corrected in conjunction with the aneurysmal repair. The aneurysm was closed at its base. Isolated patched mattress sutures were always used. If tension-free approximation seemed unlikely, a patch was instead stitched to the margin of the defect. Reoperation was required in two cases because of recurrent fistulation. No patient died and the prognosis after repair appeared to be good. The transaortic supravalvular approach is preferred as the anatomically safest way to obtain closure at the aneurysmal base. A probe passed through the defect may help to identify the chamber of entry. A VSD is most likely to be present if the rupture drains into the right ventricle. These coexistent VSDs are often located in the membranous septum and they may be amenable to transaortic or transatrial repair.(ABSTRACT TRUNCATED AT 250 WORDS)

Early and Late Patency of Aortocoronary Vein Grafts

Early patency (two weeks) of 331 aortocoronary vein grafts was 89%. Late patency (one year) of 122 restudied grafts was 80%. A cumulative one year patency of 72% was calculated. Patency was similar for SV grafts, sutured distal to stenosis and segmental obstruction. Early patency was significantly decreased when the peroperative graft blood flow was 20 ml/min or less or the diameter of the recipient coronary artery was smaller than 1.5 mm. Cumulative one year patency was lower in symptomatic patients (54%) than in those who underwent consecutive reevaluation (80%). There was a trend towards improved patency rates for graft anastomosed to the left anterior descending coronary artery and grafts without pre-existing pathological changes. Patient parameters, such as at operation, sex, smoking habits, hypertension, lipid abnormalities, diabetes, previous myocardial infarction or depressed left ventricular function, had no bearing on patency. Graft failure occurring, despite refined surgical technique, is usually due to pathological changes of the vein graft per se or the recipient coronary artery and its vascular bed.

Central haemodynamics at rest and during exercise before and after aortic valve replacement with the Bjork - Shiley tilting disc valve in patients with isolated aortic stenosis.

A pre- and postoperative haemodynamic study at rest and during exercise was performed in 37/53 consecutive patients with isolated aortic stenosis operated upon with the Bjork-Shiley tilting disc valve. After operation there was a significant average decrease in heart volume in supine position and a significant increase in working capacity. Total haemoglobin decreased slightly, but blood volume remained unchanged as did the kinetics of circulation at rest and during exercise. Left and right ventricular pump function, as judged from systolic and end-diastolic pressures, mean atrial pressures and left ventricular systolic and diastolic work, was improved following operation. Marked reductions were found in left ventricular systolic pressures at rest and during exercise. Left ventricular end-diastolic, pulmonary artery and right heart pressures decreased significantly. Pulmonary vascular resistance remained unchanged. After operation the systolic aortic pressure and pulse pressure increased significantly duri...

Failing Transcervical Thymectomy in Myasthenia Gravis: An Evaluation of Transsternal Re-exploration

Twenty cases of failing transcervical thymectomy are reported. They were selected for transsternal re-exploration from a series of 95 patients who had previously undergone transcervical thymectomy because of myasthenia gravis (MG). A specific method for pre-operative detection of remnants of the non-tumorous thymic gland is lacking, but the applied clinical selection criteria were so far reliable: generalized, disabling, fluctuating MG despite cholinesterase inhibitor and/or immunosuppressive treatment, and no or inconsistent improvement after transcervical thymectomy. At transsternal re-exploration the commonest findings were intact lower thymic lobes with persistent venous drainage into the brachiocephalic vein. Presence of thymic tissue was histologically confirmed in all the excised specimens (weight range 10-60, mean 23 g), and the examination showed thymic hyperplasia in 18 cases, fatty involution of the gland in two, and a lympho-epithelial thymoma in one case. The re-operation was followed by objectively registrable improvement in all but one of the 20 patients during observation periods of 8-75 (mean 21) months. There was statistically significant reduction in disability scores (means 8.2-4.9) and in need for anticholinesterase medication (to 67% of pretreatment dose). Immunosuppression became unnecessary in 6 of 11 patients and could be reduced in 4 patients. The incidence of failure in transcervical thymectomy was alarmingly high (27%), and more re-operations are anticipated. Since the transcervical approach involves a high risk of incomplete thymectomy, its use should be abandoned. However, in most of the patients with re-operation, subsequent progress has been sufficiently promising for advocacy of sternotomy whenever the clinical criteria of failure are fulfilled.

Coronary Ostial Stenosis

Coronary ostial stenosis developing after aortic valve replacement is a clinically well-recognized entity. This non-atheromatous intimal proliferation may be limited to the proximal part of the coronary artery, probably as a complication of intra-operative coronary perfusion. It may also occur in association with widespread intimal thickening in the aortic root, presumedly as a reaction to turbulence around aortic ball valve prostheses. We have encountered this process in 2/508 patients (0.4%), who underwent aortic valve replacement with the Bjork-Shiley tilting disc valve prosthesis. The coronary perfusion technique was identical in all the operations. Both the above-mentioned patients experienced disabling angina pectoris within 5 months of valve replacement and had developed a short stenosis proximally in the main left coronary artery. Both were relieved by coronary artery bypass grafting. Our first 160 consecutive aortic valve replacements with the Bjork-Shiley prosthesis were analysed with reference ...

Encapsulation of the Björk-Shiley Aortic Disc Valve Prosthesis Caused by the Lack of Anticoagulation Treatment

We have never experienced encapsulation or massive thrombosis of a Bjork-Shiley aortic valve prosthesis in a patient receiving an adequate anticoagulation treatment. An encapsulation has, however, been described after many different types of heart valve replacements. Early diagnosis and emergency operation are mandatory. We have only encountered two cases of massive thrombosis in Bjork-Shiley tilting disc valve prostheses in the aortic position out of 300 implants. Anticoagulant treatment was not given in either case. One patient died before final diagnosis was made and the other underwent an emergency operation. It was possible to clean out all thrombus material on both sides of the valve after temporary removal of ths disc and rotation of the valve. This method cannot, however, be recommended for general use. If the surgeons are not experienced in the proper removal of the disc, they will bend the struts so that the disc will not function properly after re-insertion. The insertion of a new prosthesis is...

Cerebral Blood Flow and Cerebral Metabolism in Children Following Cardiac Surgery with Deep Hypothermia and Circulatory Arrest. Clinical Course and Follow-Up of Psychomotor Development

Between November 1975 and June 1977, 49 children underwent repair of complicated cardiac defects with the aid of deep hypothermia. Circulatory arrest was used in 28 cases. Nine children died (18%) due to early postoperative heart failure. A decisive cause of death in terms of important cardiovascular defects, which were either unknown or not correctable at the time of repair, was found in 6 patients. Children with complicated forms of congenital heart disease requiring an extensive repair were overrepresented among those who died. Hence, there was an excess in the duration of bypass among nonsurvivors (p less than 0.01) whereas the patients age at operation, the use of circulatory arrest and the duration of aortic occlusion had no bearing on operative mortality. Cerebral blood flow (CBF) and cerebral metabolism were studied in 9 survivors. A negative correlation (r = -0.67) was found between the duration of circulatory arrest and CBF measured directly after surgery. CBF was reduced to values below 0.2 ml . g-1 . min-1 in 3 children with long periods of circulatory arrest. The cerebral uptake of oxygen and glucose was normal both before and after surgery. Two separate interviews with the parents were performed, the first one 3-22 months and the second one about 3 years after surgery. No serious neurological symptoms or psychomotor disturbances were reported. However, in 3 children operated with circulatory arrest, difficulties in performing more delicate motor activities were noted by the parents. The findings indicate that circulatory arrest should be used with caution and total arrest periods exceeding 60 min avoided.

Heparin-coated cardiopulmonary bypass circuits reduce circulating complement factors and interleukin-6 in paediatric heart surgery

Children are sensitive to the inflammatory side effects of cardiopulmonary bypass (CPB). Our intention was to investigate if the biocompatibility benefits of heparin-coated CPB circuits apply to children. In 20 operations, 19 children were randomized to heparin-coated (group HC, n = 10) or standard (group C, n = 10) bypass circuits. Plasma levels of acute phase reactants, interleukins, granulocytic proteins and complement factors were measured. All were significantly elevated after CPB. Levels of complement factor C3a (851 (791-959) ng/ml [median with quartiles] in group C, 497 (476-573) ng/ml in group HC, p < 0.001), Terminal Complement Complex (114 (71-130) AU/ml in group C, 35.5 (28.9-51.4) AU/ml in group HC, p < 0.001), and interleukin-6 (570 (203-743) pg/ml in group C, 168 (111-206) pg/ml in group HC, p = 0.005), were significantly reduced in group HC. Heparin-coated CPB circuits improve the biocompatibility of CPB during heart surgery in the paediatric patient population, as reflected by significantly reduced levels of circulating complement factors and interleukin-6.Children are sensitive to the inflammatory side effects of cardiopulmonary bypass (CPB). Our intention was to investigate if the biocompatibility benefits of heparin-coated CPB circuits apply to children. In 20 operations, 19 children were randomized to heparin-coated (group HC, n = 10) or standard (group C, n = 10) bypass circuits. Plasma levels of acute phase reactants, interleukins, granulocytic proteins and complement factors were measured. All were significantly elevated after CPB. Levels of complement factor C3a (851 (791-959)ng/ml [median with quartiles] in group C, 497 (476-573)ng/ml in group HC, p < 0.001), Terminal Complement Complex (114 (71-130) AU/ml in group C, 35.5 (28.9-51.4) AU/ml in group HC, p < 0.001), and interleukin-6 (570 (203-743) pg/ml in group C, 168 (111-206)pg/ml in group HC, p = 0.005), were significantly reduced in group HC. Heparin-coated CPB circuits improve the biocompatibility of CPB during heart surgery in the paediatric patient population, as reflected by significantly reduced levels of circulating complement factors and interleukin-6.

Late Thrombotic Malfunction of the Björk–Shiley Tilting Disc Valve in the Tricuspid Position. Principles for Recognition and Management

Among 52 consecutive patients surviving tricuspid valve replacement with the Björk-Shiley tilting disc valve, follow-up extends between 1/2-9 years, mean 4.9 years. Four patients suffered thrombotic obstruction of their tricuspid prosthesis on 8 occasions, an incidence of 3.2%/year. Ebsteins anomaly and deficient anticoagulation were identified as likely contributory factors, but the complication remained unexplained in 2/8 instances. Thrombotic malfunction of the tricuspid prosthesis seems to constitute a relatively benign clinical entity with mild manifestations and diagnostic possibilities by non-invasive methods. Relief by means of thrombolytic treatment in the form of streptokinase (Kabikinase) (4) or replacement of the clotted prosthesis (4) involved neither disabling complications nor mortality. Our clinical observations and experimental studies suggest that thrombolytic therapy is effective, provided that prosthetic malfunction is due to a recent red clot, whereas encapsulation of the prosthetic disc by organized white-grey pannus necessitates re-operation. Streptokinase treatment should be attempted before surgery, but it is hardly meaningful to proceed for more than 24 hours. Restored prosthetic function within this time limit indicates the likely resolution of a red clot.