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Biomedical subjects

A Henze

Publications and source records attributed to A Henze.

At least 55 records · Page 3Linked to original sources
PubMed1985

Penetration of penicillins into cardiac valves and auricles of patients undergoing open-heart surgery.

Prophylactic use of antibiotics in open-heart surgery for insertion of prosthetic valves is common, because of the serious consequences of postoperative staphylococcal infections, most notably prosthetic valve endocarditis. To ensure effective antibiotic cover during surgery, the penetration of cloxacillin and benzylpenicillin into the heart muscle and valves was studied intraoperatively. Both antibiotics were given intravenously (respective initial doses 2 g and 6 g) at induction of anesthesia to ten patients undergoing replacement of aortic or mitral valve, and the same doses were repeated after 4 hours. Serial serum samples and tissue samples from the right atrial auricle and the excised heart valve were analyzed for antibiotic concentrations. The mean serum concentrations of cloxacillin were 204 +/- 93 mg/l 10 min after the initial dose and less than or equal to 26 mg/l 30 min before the second dose. The corresponding values for benzylpenicillin were 323 +/- 145 and 43 +/- 24 mg/l. The cloxacillin concentrations in the auricle just before the start of extracorporeal circulation ranged from 4.5 to 80 mg/kg and (later) in the excised heart valves they were 8.5 to 45 mg/kg. The benzylpenicillin range was 16 to 153 mg/kg in auricle and 13 to 87 mg/kg in valve tissue. The authors conclude that the employed doses of the penicillins are adequate cover against the staphylococci which may be implicated in postoperative infections.

Cardiac Surgical Procedures↗
PubMed1984

Stimulating effect of mercuric chloride and nickel sulfate on DNA synthesis of thymocytes and peripheral blood lymphocytes in children.

Mercuric chloride and, to a lower extent, nickel sulfate, stimulated DNA synthesis of both thymocytes and peripheral blood lymphocytes. The metal allergens stimulated both cell types at a lower degree than lectinic mitogens (PHA, Con A and PWM) did. In peripheral blood lymphocytes the stimulation degree was higher than in thymocytes after addition of metal allergens as well as lectinic mitogens. The presence of serum seemed to have a protective and potentiating role regarding the effect of mercuric chloride and lectinic mitogens, the effect of nickel sulfate being mainly unchanged. With increasing age of the individuals, an increase in the stimulation degree with mercuric chloride and lectinic mitogens was indicated, while nickel sulfate gave a decrease.

Adolescent↗
PubMed1984

Investigation of ability of the metal allergens cobalt chloride, nickel sulfate and potassium dichromate to give a mitogenic response in human thymocytes.

The metal allergens cobalt chloride, nickel sulfate and potassium dichromate were tested for the ability to give a mitogenic response in human thymocytes, both unseparated and Percoll-separated, including a fraction of low density, which has been shown to have characteristics of medullary cells (unsensitized, virgin T cells). With cobalt chloride and potassium dichromate, no stimulation occurred; instead, cobalt chloride at a concentration of 3.5 X 10(-5) M and potassium dichromate at 5.7 X 10(-7) M were inhibiting. After nickel sulfate addition, a small DNA synthesis stimulation was obtained in both unseparated cells and in fractionated cells of different densities. The results thus speak against that cobalt chloride and potassium dichromate are unspecific mitogens for human lymphoid cells, while an unspecific mitogenic effect is indicated for nickel sulfate.

Allergens↗
PubMed1984

VSD formation in corrected TGA. Management of a previously undescribed complication after tricuspid valve replacement.

Disruption of the membranous ventricular septum following replacement of the tricuspid systemic atrioventricular valve in corrected TGA has not, to our knowledge, been reported in the literature. Our experience with this uncommon complication, which we observed and treated in two patients, is therefore presented. In the first case the native value anulus was large in relation to the largest available prosthetic valve. VSD formation occurred on the fifth postoperative day, probably due to "push and pull" forces acting on the membranous ventricular septum during the cardiac cycle. Fixation of the prosthetic sewing ring to the atrial tissue well above the adjacent membranous ventricular septum may invalidate the push and pull forces and thus be a preventive measure. In the second case the membranous ventricular septum remained intact following the primary valve replacement. When the outgrown prosthesis was excised 11 1/2 years later, disruption of the membranous septum resulted from attempts to widen the native valve anulus. This complication may be avoided if part of the sewing ring is cut away from the prosthetic valve and left in situ along the adjacent membranous ventricular septum. Sutures can be placed through the remnant of the sewing ring with minor or no risk of ventricular septal disruption.

Adolescent↗
PubMed1984

The adjustable half-moon. An alternative device for tricuspid valve annuloplasty.

The adjustable half-moon consists of a flexible braided Dacron tube fitted with two internal Teflon-impregnated sutures. The sutures are anchored at each end of the tube and can be tightened at its centre. Implantation is performed along the annular tissue corresponding to the anterior and posterior tricuspid leaflets. Shortening of the half-moon in unilateral or bilateral fashion can be accomplished after its implantation. Two prosthetic sizes are available, "small" and "large", with a tolerance between 4.5 and 9.0 cm. The device preserves the natural tricuspid valve configuration, avoids the cardiac conduction tissue, permits annular adjustment after completed implantation and provides proper support. Following positive experience in 5 cases with severe functional tricuspid incompetence further use of the adjustable half-moon is advocated.

Aged↗
PubMed1984

Repair of ventricular septal defect in the first year of life.

In the 7-year period 1976 through 1982, 48 infants underwent repair of ventricular septal defect (VSD). Their mean age was 5.3 (range 1-11) months and mean body weight 5.4 (range 3.1-9.6) kg. "Uncomplicated" VSD, located in the membranous septum, was present in 33 cases. "Complicated" VSD in terms of muscular/multiple (n = 6), subaortic type of double-outlet right ventricle (n = 5), AV-canal type (n = 2) and straddling chordae (n = 2) was present in 15 cases. The indication of surgery was progressive left ventricular dysfunction due to pulmonary hyperperfusion and pulmonary hypertension. Right trans-atrial exposure permitted repair, patch or tunnel in 43 of the 48 infants (90%), although temporary detachment of the septal tricuspid leaflet was required on six occasions. Co-existing patent ductus arteriosus (n = 6) and atrial septal defect (n = 22) were simultaneously closed. There were three postoperative deaths (6%). One infant required a second-stage repair for incomplete VSD closure and one sustained a permanent AV-block II. Repair via right atrial exposure was associated with few complications and only one death (2%).

Age Factors↗
PubMed1984

Mechanical heart valves in children.

Longterm follow-up of 17 children, who consecutively underwent replacement of one cardiac valve with the Björk-Shiley prosthesis, is presented. The children's mean age was 8 years (range 4-12 years) and body weight 23.5 kg (range 15.0-38.4 kg) at the time of surgery 1970-80. Nine of the 17 operations (53%) were second-stage cardiac surgery. The operations comprised 2 aortic and 7 mitral valve replacements, 2 implantations of prosthesis in aortoventricular plasties (Konno's operation), 4 in the functional mitral orifice of transpositions (3 congenitally corrected and one operated on a.m. Mustard) and 2 valved conduits included in the repair of complex malformations. Two deaths were associated with surgery, but were not related to the valve prosthesis per se. One patient died 37 months postoperatively, due to mechanical valve failure (early and late mortality 12% and 6%, respectively). All survivors were followed at least two years, 9 were followed at least 5 years and 6 at least 10 years (mean 7.7 years). Anticoagulation was maintained without pertinent problems. There was one thromboembolic episode (0.87%/patient year). Two patients were reoperated because of "outgrown prosthesis" after 8 and 11 1/2 years. Morbidity otherwise was low and 9 patients (53%) had no complications at all. We conclude that the mechanical valve is a suitable substitute for a seriously diseased cardiac valve in childhood. However, if valve replacement is performed in early life, the later need of exchange of the outgrown prosthesis must be faced.

Age Factors↗
PubMed1984

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.

Adolescent↗
PubMed1984

Aortoventriculoplasty ad modum Konno. Experience with five cases.

We have performed Konno's aortoventriculoplasty in 5 children with congenital valvular aortic stenosis and extreme annular narrowing. There was one hospital death, unrelated to the surgical procedure per se. Bleeding from the stitch holes along the patches immediately after bypass was the sole problem associated with the Konno operation in our 4 surviving patients. Preclotting of the dacron patch or use of calf pericardium did not significantly influence this type of bleeding complication. Konno's aortoventriculoplasty permitted considerable enlargement of the original annular circumference and insertion of a size of prosthesis appropriate for adult life (at least 21 mm tissue diameter) in the 4 survivors. The results were still good 1 to 5 (mean 3) years after surgery. The Konno operation is a safe procedure, which widens the hypoplastic aortic annulus to a possible maximum, relieves most forms of ventricular outflow tract obstruction and maintains the prosthetic valve in anatomic sub-coronary position, so that a left ventricular apical-aortic conduit is not required.

Aortic Valve↗
PubMed1983

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 VSD's which were detected at surgery. Coexistent cardiac defects (5 VSD's, 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 VSD's are often located in the membranous septum and they may be amenable to transaortic or transatrial repair.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Haemorrhagic complications during pulmonary resection. A retrospective review of 1428 resections with 113 haemorrhagic episodes.

A series of 1428 standard pulmonary resections (pneumonectomy 30%, lobectomy 66%, segmentectomy 4%) performed over a 13-year period was reviewed with regard to haemorrhagic complications. The incidence of intra-operative vascular injuries was 5%. The pulmonary artery was damaged in 50 of these 73 injuries, the pulmonary vein in 21, and the superior vena cava and the subclavian vein in one case each. Two deaths were associated with the intra-operative bleeding. The vascular lesions could be repaired without extensive resection of pulmonary tissue in all but 3 of the other patients, in whom two, three and five pulmonary segments, respectively, had to be sacrificed. Postoperative bleeding necessitated emergency thoracotomy in 37 patients (2.6% of the series), and in 3 patients autopsy disclosed such haemorrhage. The cause of the bleeding in 12 cases was slipping or cutting through of ligatures applied to divided major vessels (pulmonary artery in 8 cases, pulmonary vein in 3 and azygos vein in 1 case). Systemic arterial haemorrhage occurred in 15 patients and diffuse bleeding in 12, while one patient had a coagulation disorder causing bleeding. Nine of the 40 patients died, 7 of the haemorrhage and 2 of bronchopleural fistula. The death rate was significantly higher in postoperative than in intra-operative bleeding. The study demonstrated that the widely used and recommended transfixion suture is not absolutely safe to prevent slipping of ligatures from divided major intrathoracic vessels. A purse-string suture has proved to be a safer alternative.

Constriction↗
PubMed1982

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 patient's 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.

3-Hydroxybutyric Acid↗
PubMed1981

Repair of double-outlet right ventricle. Experience of 13 cases.

Surgery for double-outlet right ventricle (DORV) was performed in 13 patients between November 1974 and January 1979. Subaortic ventricular septal defect (VSD) was present in 11 patients, complicated forms of DORV in 2 patients and 5 patients had important concomitant cardiac defects. Six infants (mean age 0.6 years) without pulmonary stenosis (PS) required operation because of pulmonary hypertension, whereas the 7 patients with PS underwent surgery at a considerably later stage (mean age 6 years). Interventricular tunnel-repair established continuity between the systemic ventricle and great artery in 12 patients. One case with subpulmonic VSD was managed by transposition of both venous return and arterial outflow, while the use of valved external conduits was generally avoided. Atrial incision was sufficient to permit complete intraventricular repair in 8 patients, including one pulmonary valvulotomy. Important co-existing PS was otherwise treated as in cases of tetralogy of Fallot and required transannular patch grafting in 2 instances. Hospital mortality was 3/13 patients (23%) and mainly confined to serious associated cardiac malformations which were not amenable to correction. All 10 survivors are functionally improved 1.5-5 years after surgery. Clinical and invasive re-evaluation (3 patients) could not identify the development of systemic ventricular outflow tract obstruction. One patient, who underwent enlargement of a restrictive VSD, presented angiographic evidence of a moderate aortic incompetence. No other important complications were associated with the tunnel-repair and none of the 10 survivors had complete heart block.

Adolescent↗
PubMed1981

Indications for the internal mammary artery graft.

Experience of 285 internal mammary artery (IMA) grafts inserted during a five-year period disclosed an operative mortality of 1.5% when patients with associated procedures were excluded. Two of nine patients undergoing concomitant intracardiac surgery died within one month. Thus the overall operative mortality was 2.1%. Preoperative IMA graft blood flow was significantly less than that through comparable aortocoronary saphenous vein grafts. Early IMA graft patency (two weeks) was 95% and the cumulative late patency (one year) was 91%. Early patency for IMA grafts with peroperative flow less than 20 ml was 70%. None of these grafts were occluded at late follow-up. Sixteen occluded IMA grafts were related to technical problems (six grafts), inadequate graft size (five), extensive disease of the recipient coronary artery (four) and to overestimated proximal stenosis with large competitive flow enhancing early graft failure (one graft). Retrograde filing of the IMA when contrast was injected into the recipient coronary artery, was observed in 7 patients (3%). Probable causes were proximal stenosis of the graft, small sized IMA with inadequate antegrade flow and overestimated proximal coronary obstruction. Prerequisites for performing optimal IMA grafting need pre- and peroperative caution. A good calibre IMA without proximal obstructions must be available. The technique of dissecting and handling the vessel and performing anastomosis must be careful. The recipient coronary artery should be selected with consideration in order to avoid unfavourable demand-supply ratios. The IMA is most suitable for low-flow situations supplying a small amount fo myocardium distal to a high-grade coronary obstruction.

Adult↗
PubMed1981

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.

Adult↗
PubMed1981

Haemodynamic changes after tricuspid valve surgery. A recatheterization study in forty-five patients.

Changes of the central haemodynamics at rest and during exercise were evaluated in 45 patients who underwent tricuspid valve surgery. Tricuspid valve disease was associated with left heart valvular lesions in 42 patients, while isolated tricuspid valve lesions were present in 3 patients. The pre-operative evaluation showed marked impairment of cardiac function expressed by cardiomegaly, low physical working capacity, hypokinetic central circulation, elevated right atrial pressure and pulmonary hypertension in the majority of patients. Nineteen patients underwent tricuspid valve replacement and 26 tricuspid annuloplasty. The left heart valvular lesions were corrected by prosthetic valve replacement in all patients but one, who underwent mitral commissurotomy. The Björk-Shiley tilting disc valve prosthesis was used for all valve replacements. At postoperative evaluation the patients were classified in 3 groups: (1) Group TVR- 19 patients with well-functioning tricuspid valve prostheses; (2) Group TAP - 16 patients with good functional results in tricuspid annuloplasty; and (3) Group TAP-Failure - 10 patients in whom significant tricuspid incompetence was observed. The overall response to surgery in groups TVR and TAP was about the same, leading to an increase in working capacity and cardiac output and a decrease in heart volume, right atrial pressure and pulmonary hypertension. In the TAP-failure group, this response was limited to an increase in cardiac output and mainly attributable to the corrected left heart lesions. Sustained pulmonary hypertension, failing left ventricular myocardium, residual left heart lesions and anatomical tricuspid valve changes were the likely causes of TAP-failure, which could not be predicted from the pre-operative evaluation.

Adult↗
PubMed1980

Comparison of Kay's and de Vega's annuloplasty in surgical treatment of tricuspid incompetence. Clinical and haemodynamic results in 62 patients.

This paper compares the late results of Kay's and de Vega's annuloplasty in the management of tricuspid incompetence. The operations were done in 62 consecutive patients during the nine-year period 1969-77 and included simultaneous correction of acquired valvular lesions (58/62) and congenital malformations (4/62). Kay's bicuspidalization and de Vega's annular plication were performed in 27 vs. 35 patients and these two groups were similar in the most important respects. Tricuspid regurgitation was recognized in 44/62 patients (71%) before surgery, whereas in 18/62 patients (29%) it was diagnosed at intra-operative exploration. The majority of cases (84%) were functional in origin and 16% had anatomical lesions causing or contributing to significant incompetence. Most of the patients (90%) belonged to functional class III or IV (N.Y.H.A.) before operation. The type of tricuspid repair had no bearing on early (11% vs. 14%) and late mortality (5.8%/year vs. 5.0%/year). Re-evaluation in 50 patients showed that Kay's bicuspidalization and de Vega's annular plication gave similar and good late result in about 70% of the cases. The risk of over-correction was low in that only 1/30 cardiac catheterization revealed signs of mild tricuspid stenosis. Recurrent or residual tricuspid incompetence is probably related to the severity of the individual cases. Some of these failures were evident already on the patient's discharge from hospital but, unfortunately, not predictable from the pre- or intra-operative evaluations.

Adolescent↗