Outer radius-wall thickness ratio, a postmortem quantitative histology in human coronary arteries

Although the anatomy, histology and pathology of human coronary arteries have been studied extensively, little is known about the functional relationship between vessel radius and wall thickness. It is the purpose of this study to present detailed measurements and to describe this relationship covering the range from the feeding coronary artery to the arterioles. Human hearts of 10 adults less than 36 +/- 3 years old were investigated immediately postmortem. Ten cubic tissue blocks, measuring about 10 mm in length on each side, were dissected from the left ventricular wall. After fixation by immersion, 15-microm sections were prepared and outer and inner perimeters of 52 arterial segments were digitalized. Vessel radius and wall thickness were calculated and plotted to show their relationship over the whole range of vessel calibers. Outer vessel radii ranged from 100 to 3,000 microm and wall thickness from 80 to 800 microm. Plotting the outer vessel radius against the wall thickness, the data points were found to cluster around a straight line. A significant correlation between the two parameters was found (R2 = 0.79). This mathematical correlation and the good agreement of the presented results with data from other species indicate a common physiologic concept.

[Partial left ventriculectomy (Batista-procedure) as an alternative to transplantation and as a rescue procedure]

Partial left ventriculectomy (Batista operation) is one of several surgical options for the treatment of end-stage heart disease. In a 17-year-old patient who could not be accepted as a candidate for heart transplantation, this procedure was performed as an acute rescue procedure in conjunction with reduction of the left ventricle, single-stitch reconstruction of the mitral valve and removal of a ventricular thrombus. Following temporary dependence on mechanical circulatory support the patient was transferred to his own country. The clinical experience is discussed, including aspects of the surgical technique, postoperative complications, indication, relevance of mitral reconstruction and rhythm problems. It is concluded that partial left ventriculectomy can be used to treat end-stage dilated cardiomyopathy, even as an emergency operation. Further studies and experience are needed to clarify the long-term effects and clinical limitations of the procedure.

Proposed entry criteria for postoperative cardiac extracorporeal membrane oxygenation after pediatric open heart surgery

While extracorporeal membrane oxygenation (ECMO) is being used increasingly after pediatric cardiac surgery, criteria are lacking for initiating ECMO after bypass weaning. To develop clinically useful ECMO entry criteria based on parameters readily available, children were examined at postoperative pediatric intensive care unit (PICU) admission. Using hospital mortality as the primary outcome, univariate and multiple logistic regressions were performed to estimate the predictive value of clinical (age, weight, and diagnosis) and laboratory (arterial blood pressure, pH, lactate, creatine kinase, and arterial and central venous oxygen saturation [ScvO2]) variables. Data from 218 children over a 2 year period were analyzed retrospectively. Univariate regression demonstrated that age, weight, diagnosis, blood pressure, venous and arterial saturation, and lactate were significantly associated with postoperative mortality (p < 0.05). In multiple regression, ScvO2 and lactate level were found to be independent predictors and were used in a predictive model (ScvO2 odds ratio: 2.03-828.6, p = 0.016) (lactate odds ratio: 1.58 -4.20, p = 0.0002) (R2 = 0.70). Applying an 80% risk of mortality to establish entry criteria as in neonatal ECMO, PICU admission values of lactate > 70 mg/dl if ScvO2 < 60% or lactate >163 mg/dl if ScvO2 > 60% are proposed to serve as postoperative ECMO entry criteria if bypass weaning has been possible but is followed by low cardiac output.

Surgical aspects of pediatric cardiac extracorporeal membrane oxygenation

Because children with severe myocardial dysfunction have limited therapeutic options, mechanical support of a failing heart is a matter of great interest. In the setting of cardiogenic shock or severe low cardiac output and hypoperfusion, extracorporeal membrane oxygenation (ECMO) can produce decisive improvements. The criteria for successful treatment include appropriate patient selection, improved surgical techniques and experience, higher recognition and anticipation of complications, and minimized delay in initiation of ECMO. Because the need for mechanical circulatory support may arise pre-, intra-, and postoperatively, every pediatric cardiac surgeon must be familiar with the principles and the surgical aspects of ECMO.

Acute clinical deterioration in a patient with end-stage dilated cardiomyopathy and left ventricular thrombus formation

The case of a 17-year-old male patient with severe end-stage dilated cardiomyopathy and a large thrombus formation within the cavum of the left ventricle is reported. After an acute thrombectomia combined with a partial left ventriculectomy (Batista procedure), the patient was successfully treated with an appropriate left ventricular assist device (LVAD) system using a centrifugal nonocclusive pump (Biomedicus, Medtronic, Anaheim, CA, U.S.A.). Mechanical support was removed on Day 9, and the patient was discharged from the hospital on Day 19. The effectiveness of emergency mechanical support in patients with very unfavorable prognoses is discussed.

Excessive bleeding on extracorporeal membrane oxygenation after surgical repair of type I truncus arteriosus: A case report

Severe bleeding remains the most common complication of extracorporeal membrane oxygenation (ECMO) following surgical repair of congenital heart defects. We present a case of excessive hemorrhage within the first hours on ECMO support after repair of a type I truncus arteriosus. Bleeding control was achieved by surgical repair following failure of conventional interventions to control hemorrhage despite normalization of laboratory coagulation parameters. Aspects associated with bleeding and bleeding control during extracorporeal circulation after cardiac surgery are discussed.

Valve-preserving treatment of Ebstein's anomaly: perioperative and follow-up results

BACKGROUND

Ebstein's anomaly is a rare congenital cardiac defect of the tricuspid valve (TV) leading to severe tricuspid insufficiency (TI).

METHODS

In ten patients, 6 adults (39-53 years) and 4 children (5-10 years), operated between 1989 and 1995 echocardiography was performed pre and post repair and at follow-up. Patients were assessed in our institution at two cut-off points, resulting in a mean first follow-up of 17 +/-15 months and a mean second follow-up of 53+/-23 months. All patients had additional congenital cardiac defects (ASD,VSD). In all patients the TV was repaired by techniques described by Carpentier et al. with some modifications. The goal of this reparative attempt is to mobilize restricted leaflet tissue and aid coaptation through implantation of a ring.

RESULTS

Echocardiographically we were able to identify significant characteristics for the successful repair of Ebstein's anomaly. The severity of the disease is represented by the size and function of the right ventricle and the atrialized chamber, the most advanced cases exhibiting a dilated right ventricle with poor contractility. There was severe preoperative TI ( mean grade 3.2 +/- 0.3). Postoperatively TI was significantly reduced to a mean grade of 2+/-0.2. 60% of the patients demonstrated an improvement in the ratio of atrialized chamber to functional right ventricle. Right-ventricular function was improved, the mean score being 2.8+/-0.1. At follow-up I and II right-ventricular function and tricuspid insufficiency was improved in most patients and all patients benefited in quality of life.

CONCLUSION

These results suggest that surgical correction should not be delayed until severe right heart failure develops as, particularly in children, good results are achieved, improving the quality of life.

Mechanisms underlying aortic dilatation in congenital aortic valve malformation

BACKGROUND

The high incidence of aortic disease in subjects with congenital aortic valve malformations suggests a causative relationship between these 2 conditions. The histological observation in aortic dilatation/aneurysm/dissection is Erdheim cystic medial necrosis (CMN), a noninflammatory loss of smooth muscle cells (SMCs), fragmentation of elastic fibers, and mucoid degeneration.

METHODS AND RESULTS

To examine whether apoptosis is 1 of the mechanisms underlying CMN and aortic medial layer SMC loss, ascending aortic wall specimens from 32 patients were collected at cardiothoracic surgery and examined by histochemical staining and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling. From echocardiography results, 4 groups of patients were identified: bicuspid valve carriers with (bi/dil) or without (bi/0) aortic dilatation and tricuspid valve carriers with (tri/dil) or without (tri/0) aortic dilatation. Massive focal apoptosis was observed in the medial layers of bi/dil (mean apoptotic index [mAI], 8.1+/-6.0) and tri/dil (mAI, 8.1+/-8.3) compared with tri/0 (mAI, 0.9+/-1.2; P=0.0079 and P=0.037). In bi/0 (mAI, 9.1+/-5.7) compared with tri/0 (mAI, 0.9+/-1.2), rates of medial SMC apoptosis were increased (P=0.0025). Bi/dil (mean age, 40. 6+/-15.7 years) were significantly younger than tri/dil (mean age, 56.4+/-12.8 years) undergoing the same operation (P=0.0123).

CONCLUSIONS

Premature medial layer SMC apoptosis could be part of a genetic program underlying aortic disease in patients with aortic valve malformations.

IgG subclass reactivity to human cardiac myosin in cardiomyopathy patients is indicative of a Th1-like autoimmune disease

Studies performed in mice together with the demonstration of increased levels of heart-specific autoantibodies, cytokines and cytokine receptors in sera from cardiomyopathy (CMP) patients argued for a pathogenic role of autoimmune mechanisms in CMP. This study was designed to analyse the presence of IgG anti-heart antibodies in sera from patients suffering from hypertrophic and dilatative forms of CMP as well as from patients with ischaemic heart disease and healthy individuals. Patients' sera were analysed for IgG reactivity to Western-blotted extracts prepared from human epithelial and endothelial cells, heart and skeletal muscle specimens as well as from Streptococcus pyogenes. The IgG subclass (IgG1-4) reactivity to purified human cardiac myosin was analysed by ELISA. While sera from CMP patients and healthy individuals displayed comparable IgG reactivity to a variety of human proteins, cardiac myosin represented the prominent antigen detected strongly and preferentially by sera from CMP patients. Pronounced IgG anti-cardiac myosin reactivity was frequently found in sera from patients with dilatative CMP and reduced ventricular function. ELISA analyses revealed a prominent IgG2/IgG3 anti-cardiac myosin reactivity in CMP sera, indicating a preferential Th1-like immune response. Elevated anti-cytomegalovirus, anti-enterovirus IgG titres as well as IgG reactivity to nitrocellulose-blotted S. pyogenes proteins were also frequently observed in the group of CMP patients. If further work can support the hypothesis that autoreactivity to cardiac myosin represents a pathogenic factor in CMP, specific immunomodulation of this Th1- towards a Th2-like immune response may represent a promising therapeutic strategy for CMP.

Evidence against the current hypothesis of "gene dosage effects" of trisomy 21: ets-2, encoded on chromosome 21" is not overexpressed in hearts of patients with Down Syndrome

BACKGROUND

The major current concept for the pathogenesis of the Down Syndrome (DS) phenotype including congenital heart disease (CHD) is the so-called "gene dosage effect." According to this hypothesis, genes encoded by chromosome 21 at the "critical region" (which is thought to be crucial for the development of the DS phenotype) are overexpressed in the trisomic state, thus leading to an imbalance of genes as, e.g., the protooncogene ets-2, superoxide dismutase, etc.

METHODS

We studied heart biopsies obtained at surgery from 6 patients with DS and 7 patients with congenital heart disease. ets-2-mRNA steady state levels were determined by a competitive reverse transcription-polymerase chain reaction (RT-PCR) technique which allowed the determination of this gene at the attomol level.

RESULTS

ets-2 mRNA in total ventricular tissue of DS patients showed concentrations of 0.60 +/- 0.42 fg/10 ng total RNA (mean, +/- SD). When normalized versus the housekeeping gene beta-actin to rule out general transcriptional changes in that disorder, the ratio of 0.56 +/- 0.28 (mean, +/- SD) was calculated. ets-2 mRNA in total ventricular tissue of patients with non-DS CHD showed concentrations of 0.45 +/- 0.22 fg/10 ng total RNA (mean, +/-SD) and ratios of 0.48 +/- 0.35 (mean, +/-SD). No differences could be found at the p<0.05 level.

CONCLUSION

No absolute quantification of a gene incriminated in the "gene dosage effect-hypothesis" was performed so far and the only approach to (semi-) quantitative determination of the ets-2 gene using northern blotting was published on one individual DS sample only. This is the first report to clearly show that no overexpression of ets-2 can be found in heart of patients with DS, thus providing evidence against the current gene dosage effect-hypothesis.

[Hypoplastic left-heart syndrome. Initial intensive care experiences with the Norwood operation in Vienna]

Palliative surgery of the hypoplastic left heart syndrome (HLHS), whereby both pulmonary and systemic circulation are restored, was first described by Norwood in 1983. Careful ventilatory and pharmacologic modulation of the ratio of pulmonary to systemic vascular resistance are a crucial part of pre-, peri- and postoperative management. We report our experience in 3 of 7 newborns with HLHS who underwent the Norwood operation. Hemodynamic and respiratory parameters were evaluated retrospectively in these patients and we analysed the influence of diagnostic and therapeutic interventions on the course of disease before and after operation. During prostaglandin therapy two of three patients required mechanical ventilation preoperatively because of pulmonary hyperperfusion. Decreased myocardial contractility, oliguria and increased pulmonary vascular resistance characterized the postoperative course. The management included a careful application of inotropic support when necessary, adaptation of the ventilatory setting in order to modulate pulmonary perfusion and, in addition, institution of peritoneal dialysis. One patient died from staphylococcus aureus and superinfection with respiratory syncytial virus on day 41 after the operation. Maintaining an optimal balance between pulmonary and systemic blood flow is an essential aspect of postoperative management. Serum lactate and central venous oxygen saturation are helpful parameters in monitoring therapeutic measures in these patients. We conclude from our preliminary experience, that the Norwood operation might be an alternative therapeutic approach for newborns with HLHS in whom heart transplantation is not possible.

Reversal of ventricular dilatation after correction of aortic incompetence: mechanical prosthesis compared with biological procedures

BACKGROUND

The aim of the study was to compare early differences in reversal of LV dilatation between patients with mechanical prosthesis = group A (n = 51: Carbomedics = 40, Tekna/Edwards = 11) and biological procedures = group B (n = 75: pulmonary autograft = 36, aortic valve repair = 29, homograft = 10).

METHODS

Since 1,990,126 consecutive patients younger than 50 years who had surgical correction of isolated aortic incompetence underwent echocardiographic examinations preoperatively, at discharge, and at one-year follow-up. Left-ventricular (LV) diameters were measured (LVEDD, LVESD) and matched to body surface area (LVESDI, LVEDDI and fractional shortening (FS) was calculated. Aortic peak flow velocities were assessed by Doppler technique and gradients were calculated.

RESULTS

There were no significant differences preoperatively in aortic incompetence, NYHA classification, LVEDDI, LVESDI, and FS. In group B there was a significant decrease of LVESDI (p < 0.002) and LVEDDI (p < 0.001) but no change in FS at discharge. In group A a significant reduction of FS (p < 0.05) without any significant changes in LV size was observed. No patient died perioperatively or during the first year. At one-year follow-up (complete in 97.6% patients) there were no significant differences in LV diameters but group B had better ventricular function (p < 0.05) resulting in better NYHA classification (p < 0.05). Only group B had normal aortic valve gradients at discharge and at follow-up (A: 25.2 +/- 4.3 vs B: 10.2 +/- 2.4 mmHg).

CONCLUSIONS

Normal aortic valve gradients in patients after aortic valve repair or allograft replacement for chronic aortic incompetence lead to early recovery from ventricular dilatation and significantly better ventricular function at discharge. One year postoperatively they had improved ventricular function and NYHA class in comparison with patients in whom a mechanical prosthesis was implanted.

Extracorporeal membrane oxygenation in neonates

BACKGROUND

Extracorporeal membrane oxygenation (ECMO), originally developed as an artificial replacement for respiratory assistance, is decreasingly used in neonates with respiratory failure. Nevertheless, there is a constant need for this invasive and expensive neonatal treatment modality.

INTERVENTION

Review of our experience (80 recent ECMO performances because of circulatory failure) and the literature.

RESULTS

In contrary to reduced ECMO performances out of respiratory insufficiency in neonates, ECMO as circulatory support is increasingly used. Neonatal sepsis, pre- and postoperative cardiac failure, combined circulatory and respiratory failure after resuscitation and with congenital diaphragmatic hernia result in a permanent need for ECMO, whenever there are fewer ECMO treatments per year. Nonocclusive pumps, portable devices, small priming volumes and tapered anticoagulation protocols enable survival through ECMO even in virtually hopeless hemodynamic conditions. Special efforts in investigation and prevention of permanent neurological impairment, especially after severe pre-ECMO hypoxia seem to be mandatory.

CONCLUSION

ECMO remains an important tool in neonatal and pediatric intensive care. However, the number of ECMO therapies was reduced due to respiratory therapeutic progress, but indications and ECMO technology have changed.

Single needle venovenous extracorporeal membrane oxygenation using a nonocclusive roller pump for rescue in infants and children

In 1993, J.Y. Chevalier described a single needle venovenous extracorporeal membrane oxygenation (ECMO) system using a nonocclusive roller pump and alternating clamps for pulmonary support in neonates. We modified this system to use it in older children as well and for additional indications. Introducing a double raceway and 2 different sizes of tubing sets and performing percutaneous approach, we treated 21 children (age 1 day to 49 months) using this system. Indications for treatment were hypoxia and hypoxic induced myocardial dysfunction resulting from pulmonary failure, sepsis, and congenital defects. Of the children treated for neonatal indications, 7/9 survived. For 2 children ECMO was terminated because of intraventricular hemorrhage (IVH). In the pediatric group 5/7 of the children could be weaned from ECMO, and 2 children died after more than 30 days on ECMO. Two of the children who had been almost completely weaned died later because of therapy withdrawal following a brain death diagnosis. In the cardiac group, 3/5 of the children survived. We conclude that the described system is an effective venovenous ECMO system that reduces invasivity and expenditure.

Preoperative ECMO in congenital cyanotic heart disease using the AREC system

BACKGROUND

In cyanotic congenital heart disease, oxygen delivery is impaired either by reduced pulmonary perfusion or by limited entry of oxygenated blood into the systemic circulation. Additional impairment of oxygen delivery (eg, in pulmonary hypertension) leads to hypoxic cerebral damage. Preoperative extracorporeal membrane oxygenation enables oxygenation in otherwise untreatable cases.

METHODS

In 3 neonates suffering from cyanotic congenital heart disease (1 with tricuspid atresia and 2 with transposition of the great arteries) with arterial desaturation despite application of prostaglandins, balloon atrioseptostomy, and eventually inhaled nitric oxide during intermittent positive-pressure ventilation with an inspired oxygen fraction of 1, oxygenation could only be established by means of preoperative extracorporeal membrane oxygenation. We used a venovenous single-lumen cannula tidal-flow extracorporeal membrane oxygenation system described by Chevalier and associates that has previously been used for extracorporeal lung support. In this system, called AREC (assistence respiratoire extra-corporelle), alternating clamps and a nonocclusive roller pump were used.

RESULTS

All 3 survived.

CONCLUSIONS

We conclude that the AREC system enables sufficient preoperative oxygenation in patients with cyanotic congenital heart disease and hypoxia in spite of all conventional therapeutic means. This provides a stable preoperative condition for elective palliation or correction.

Epicardial branches of the coronary arteries and their distribution in the rabbit heart: the rabbit heart as a model of regional ischemia

BACKGROUND

The rabbit heart has been frequently used to study regional ischemia, but there is hardly any detailed information on the epicardial branching of the coronary arteries. Therefore, we wanted to determine whether there is a constant branching pattern and how comparable this pattern is with the human heart.

METHODS

We investigated epicardial branching of the coronary arteries in 30 adult rabbit hearts. For vessel visualisation, we used injections of Technovit, followed by corrosion.

RESULTS

We found that there is not one constant pattern but rather a bifurcation or a trifurcation of the arteria coronaria sinistra (15 of 15 hearts). The left coronary artery is always the dominant artery; a vessel comparable to the human ramus interventricularis anterior is rarely found in the bifurcation type. The ramus circumflexus is a constant but minor branch of the posterior or posterolateral division and does not originate directly from the main stem of the left coronary artery, as it does in humans. As a consequence, ligation of the left ramus interventricularis anterior leads to severe ischemic injury only where trifurcation exists (50% of our population). A ligation of the ramus circumflexus proximal to its origin produces a large posterolateral infarction in the bifurcation type (50% of our population).

CONCLUSIONS

Because a defined ischemic area is difficult to reproduce under these anatomical conditions, the rabbit heart may be a model only for regional ischemia if the investigator is knowledgeable about the distributions of the coronary arteries.

[Aortic coarctation--long-term follow-up in adults]

Surgical repair of coarctation of the aorta has been performed since 1945. Although surgical techniques have improved, problems such as restenosis and aneurysm at the operation site or hypertensive cardiovascular disease, still remain. To evaluate the long-term results after surgical repair of coarctation, 41 patients, 25 male and 16 female patients (mean age: 28 +/- 11 years, range 14-57 years), were studied 16 +/- 8 years after surgery (range 3-44 years). Mean age at surgery was 12 +/- 9 years (range 0.5-35 years). In 24 patients resection and end-to-end anastomosis had been performed, patch graft aortoplasty in nine patients, tube interposition graft in seven patients and one patient had undergone the subclavian flap technique. All patients were assessed by exact physical examination, the resting arm-to-leg systolic pressure gradient was measured by Doppler sonography, a bicycle exercise test and an echocardiogram were performed. Twenty-one patients reported postoperative symptoms such as dizziness (n = 12), headache (n = 3), cold legs (n = 10) and/or dyspnea (n = 8). In two patients the resting arm-to-leg pressure gradient was greater than 30 mm Hg, in two patients it was greater than 20 mm Hg. Gradient calculated by Doppler echocardiography ranged from 0 to 80 mm Hg (21 +/- 17 mm Hg) and showed poor correlation with the arm-to-leg pressure difference. The mean functional capacity was 89 +/- 18% (range 42-110%). In 18 patients exercise-induced hypertension was found, while in only eight patients arterial hypertension had already been known. To evaluate the morphology of the aorta MRI was performed in 28 patients. No aneurysm was found. In five patients a minimal lumen diameter as small as 9-11 mm was measured. Patients were divided into two groups according to their age at operation, group I: < 9 years (n = 19) and group II: > 9 years (n = 22). Resting blood pressure was significantly higher in group II (135 +/- 27 mm Hg vs 114 +/- 20 mm Hg, p < 0.009), anti-hypertensive medication (43% vs 11%, p < 0.04) and symptoms were more frequent in these patients (15/22 vs 6/19, p < 0.04). However at time of follow-up examination the age of patients of group II was significantly higher (33 +/- 12 vs 22 +/- 5 years, p < 0.0005). Between these two groups there was no difference in follow-up time and results of echocardiography or stress test. In conclusion, despite good long-term results after surgical repair of coarctation of the aorta, patients should be followed on a regular basis primarily in order to recognize systemic hypertension as early as possible and to improve the long-term outcome in these patients by antihypertensive treatment.

Therapeutic strategy in a 9-month-old child with pulmonary sling: need for bronchoscopic evaluation

A 9-month-old child presented suffering from repeated severe infections of the lower respiratory tract. Bronchoscopy revealed a tracheal stenosis, suggestive of a vascular anomaly of the great arteries. A second significant stenosis of the left main stem bronchus was observed that was suspected to be due to a ligamentum arteriosum. Heart catheterization confirmed the diagnosis of an abnormal origin of the left pulmonary artery (pulmonary sling). Based on the bronchoscopic and angiographic findings a pulmonary ring was suspected. A dissection of the ligamentum arteriosum was performed. At readmission 4 weeks postoperatively the child was asymptomatic and the left main bronchus was patent.

Complete repair of PA-VSD with diminutive or discontinuous pulmonary arteries by transverse thoracosternotomy

BACKGROUND

Optimal treatment and the optimal sequence of surgical and interventional steps to correct pulmonary atresia with ventricular septal defect and hypoplastic or discontinuous intrapericardial pulmonary arteries is still under discussion. Collateral arteries may be hardly accessible through median sternotomy at total correction. Bilateral transsternal thoracotomy gives wide access to the heart, both pleural spaces and hilar structures.

METHODS

We used this incision for total correction of pulmonary atresia with ventricular septal defect in 6 patients. Three had Blalock-Taussig shunts placed previously, and intrapericardial pulmonary arteries were absent in all patients but 1, in whom they were hypoplastic. Central pulmonary arteries were enlarged with pericardial patches or replaced with tube grafts; the number of unifocalized collateral arteries varied between two and eight.

RESULTS

One patient died of respiratory failure and sepsis (16.7%). Oxygen saturation increased from 76% (range, 65% to 88%) preoperatively to 96% (range 91% to 99%) postoperatively. Mean postoperative pulmonary artery pressure was 30 mm Hg (range, 28 to 34 mm Hg). One patient had to be reoperated on through the same incision due to scarring and shrinkage of the peripheral anastomoses. Six months after operation 2 patients are in New York Heart Association functional class I and 2 are in class II.

CONCLUSIONS

Transverse thoracosternotomy gives excellent access to the anatomical structures necessary to correct complex cases of pulmonary atresia with ventricular septal defect and may reduce the number of surgical procedures.

Preischemic bolus application of piroximone studied on the isolated rabbit heart--a second look including biochemical data

In a randomized prospective experimental study on 48 adult white Elco rabbits biochemical and rhythmic changes after bolus administration of the phosphodiesterase inhibitor piroximone were investigated using a working heart model. The treatment group (n = 21) intravenously received 1 mg/kg of piroximone 15 min before thoracotomy. Twenty-three untreated hearts served as the control group. From 6 hearts of each group myocardial biopsies were taken before ischemia, 4 (2/2) hearts were excluded. Hemodynamic results of a previous study with an identical protocol were reanalyzed; a biochemical analysis of myocardial high-energy phosphates was investigated after 60 min of global ischemia and at the end of the experiments after 45 min of reperfusion. Already prior to ischemia, in the treatment group depletion of high-energy phosphates was detected. After 60 min of ischemia during early reperfusion in the treatment group ATP and creatine phosphate depletion became even more evident and increased until the end of the experiments. The incidence of reperfusion-induced arrhythmias was significantly lower in the treatment group. Consequently these results and the hemodynamic results of prior studies indicate a possible positive effect of piroximone during the early reperfusion period by optimizing hemodynamics and arrhythmias.

Closure of muscular ventricular septal defects through a left ventriculotomy

OBJECTIVE

To evaluate the results of closure of muscular ventricular septal defects through a left thoracotomy.

METHODS

Records of 23 children operated consecutively between 1972 and 1990 were studied. Age of patients was 2.8 +/- 3 years (2 months-10 years), weight 8.9 +/- 5.7 kg (2.6-22 kg). Ten patients (43%) had undergone one and 4 patients (17%) two previous cardiac operations. Late follow-up was obtained from direct examination of patients or from reports of their referring physicians. Bypass time was 89 +/- 28 min (66-167 min). The aorta was cross-clamped for 44 +/- 15 min (21-66 min). Until 1977 operations were performed with moderate hypothermia and intermittent aortic cross-clamping. After 1978 deep hypothermia (20-25 degrees C) and cold crystalloid cardioplegia was used. Ventricular septal defects not accessible from other approaches were closed through a small fish-mouth incision in the apex of the left ventricle. Patients' data were sampled and stored in a computerised database. Risk factors were evaluated by stepwise logistic regression.

RESULTS

Four patients died in the hospital (17%); two died later. Two required reoperation for residual/recurrent defects. All patients, except two from abroad, were available for follow-up, which ranged from 36 months to 18 years (mean 11.3 years). All were in NYHA class I. Only two risk factors were identified: the number of ventricular septal defects (P < 0.05) and associated atrial septal defect (P < 0.02). Early echocardiographic evaluation showed good LV size and function in all except one patient, who had a perioperative septal infarction. Late echocardiography performed in six patients demonstrated normal LV shortening without evidence of regional wall abnormality.

CONCLUSIONS

Left ventriculotomy is a useful approach for closure of low muscular ventricular septal defects in selected patients.

Thoracoabdominal aneurysm repair: spinal cord protection using profound hypothermia and circulatory arrest

Between January 1991 and February 1993, 14 patients (11 male, 3 female) between 21 and 79 years of age (median 50 years) underwent reconstruction of the thoracic (n = 7) and thoracoabdominal aorta (n = 7). Four patients had previously undergone operation of the ascending aorta, and in three patients coronary artery bypass grafting had previously been performed. All patients were operated on a via a posterolateral thoracotomy using cardiopulmonary bypass with continuous blood cardioplegia and hypothermic circulatory arrest (11 degrees C nasopharyngeal temperature, flat-EEG). All patent lower intercostal and lumbar arteries (T3 to L5) were reimplanted. The 30-day mortality after repair of the thoracic aorta was 0%; after replacement of the thoracoabdominal aorta, mortality was 28.5% (n = 2). One patient died 70 days after replacement of the thoracic aorta as a consequence of a perioperative stroke. None of the surviving 11 patients developed a permanent neurological deficit or renal or cardiac dysfunction. The average intensive care stay was 6 days for patients after replacement of the thoracic aorta and 18 days for patients after replacement of the thoracoabdominal aorta. Our results suggest that use of elective hypothermia and circulatory arrest for spinal cord protection is highly effective. We, therefore, recommend this method for complex reconstructions of the thoracoabdominal aorta.

[Heart transplantation and sexuality. A study of 62 male patients]

119 adult male Austrian patients who had undergone heart transplantation between January 1985 and December 1990 were questioned on sexual functional disorders pre- and postoperatively. Questions dealt with perceived medication effects on sexual function and libido, fear of intercourse, their worries about the sexual habits of the donor, perceived changes in sexual attractiveness and body image. They were also asked how they felt about discussing sexual matters with their doctors. 62 patients returned fully completed questionnaires. 75% of the patients were more than 45 years old (45 to 67 years). Heart transplantation had been carried out at least once longest seven years before. The patients reported a significant postoperative increase of libido accompanied by a significant decrease of physical complaints at intercourse. Problems with potency (impaired erectile rigidity) persisted, however, (Table 4, Figure 1). 23% of the patients reported that since transplantation sexuality had become a problem for them. 42% wanted to undergo treatment if available. 29% stated that sexual matters had clearly improved. 31% suspected that medication adversely affected sexual functioning, and 23% stated that in their opinion it contributed to a lowered libido. 15% felt themselves much more sexually attractive after they had undergone surgery, and 13% were considered more sexually attractive by their spouses. Only four patients reported avoiding intercourse for health reasons. One patient confirmed that he was fantasizing about the sexual habits of the unknown donor of his heart. It seems that physicians often neglect to talk about sexual matters with their heart transplant patients, though the patients consider it a very important topic (Figure 2).(ABSTRACT TRUNCATED AT 250 WORDS)