Biomedical subjects
Publications and source records attributed to H Shuhaiber.
A 23-year-old female with an echinococcal cyst in the atrioventricular groove of the heart is reported. The diagnosis and the location of the cyst were confirmed by echocardiography and cardiac catheter. Successful enucleating of the cyst with the aid of cardiopulmonary bypass and the length of follow-up is reported, along with a review of relevant literature.
Echinococcosis remains an endemic surgical problem in countries where sheep and cattle raising is carried out, particularly in many Mediterranean countries. The life cycle of echinococcosis is usually marked by the filtration of larvae through the liver and lungs which are the organs most commonly affected by a hydatid cyst. Hydatid cysts in other sites are not common. Cardiac echinococcosis has been reported infrequently even in countries in which hydatid disease is endemic, only isolated sporadic cases have been reported in the literature. Here we report a case of polyvisceral hydatid cyst with involvement of heart and chest wall and reviewed the literature and discussed clinical procedures and management.
Timing of surgical intervention in Brucella endocarditis remains controversial. In this report, we review our experience in an attempt to collect some information on the best approach for this entity. From June 1992 to December 1996, 5 male patients between the ages of 20 and 35 years with Brucella endocarditis were operated on in our centre. Three of them had native valve endocarditis (NVE) and 2 with prosthetic valve endocarditis (PVE). All patients belonged to New York Heart Association (NYHA) class III-IV. All had developed anti Brucella antibodies with serum agglutination titres of > 320 and the sera tested from 3 patients were Enzyme Linked Immunosorbent Assay (ELISA) positive for anti-Brucella IgM and/or IgG antibodies. In 3 cases 2D-echocardiography showed large vegetation on the affected valve. Blood cultures were positive in 4 patients, 2 of them (one each of NVE and PVE) had the valve material culture positive for Brucella. All cases were treated with a combination of doxycycline, refampicine and gentamicin before surgery. Major indication for surgical intervention was severe haemodynamic instability which developed during the course of antibiotic therapy either early (3 cases) or late (2 cases). All patients became asymptomatic at the end of 7 days postoperatively. On the follow-up for a period of 8-51 months, all patients were in NYHA class I-II without evidence of recurrence of infection. These data suggest that in either NVE or PVE Brucella, medical therapy alone may not be sufficient due to the eventual haemodynamic deterioration secondary to valve tissue destruction or dysfunction of the prosthetic valve caused by the infective process. Therefore, a combination of aggressive medical therapy with multiple bactericidal antibiotics and early surgical intervention may result in a successful outcome, but further studies are needed to reach a reliable conclusion.
Fungal endocarditis has emerged as an important complication of patients undergoing cardiovascular surgery. Our patient had no past history of cardiac surgery, intravenous drug abuse or immunosuppressive therapy. He had received broad-spectrum antibiotics for varying periods, which might have predisposed him to this infection. The diagnosis was based on the demonstration of hyaline, septate branched fungal elements in the infected valvular tissue and isolation of Aspergillus flavus in culture. The delay in establishing the ante-mortem diagnosis because of repeatedly negative blood cultures, presence of disseminated intravascular coagulopathy and rapidly deteriorating kidney function were the major factors contributing to his poor prognosis and death, despite surgical removal of infected valves and antifungal therapy. This is the first report of endocarditis due to A. flavus from the Middle East.
We report here a chronic haemodialysis patient who had severe anaemia following replacement of his aortic valve. The investigations confirmed a traumatic valve effect. The surgeons were reluctant to replace the valve because of the high cardiothoracic risk and absence of significant leak or stenosis. Furthermore, the patient refused to consider additional surgery. We changed his modality of dialysis to continuous ambulatory peritoneal dialysis; subsequently, there was a dramatic decrease in his transfusion requirement, and the patient was symptomatically and functionally better. A literature search indicates that this therapeutic response has not been reported before.
The role of the endothelium to influence smooth muscle contraction in normal and varicose veins was investigated in vitro using saphenous vein preparations obtained at vascular surgery. Paired control and endothelium-denuded rings were tested simultaneously and contracted with noradrenaline (10(-9)-10(-4) M). Identical experiments were also performed on sheep femoral veins and arteries. Noradrenaline induced maximal tension was 30% lower in varicose compared to normal veins. In normal veins removal of endothelium significantly reduced the maximal response to noradrenaline by 40% whereas in varicose veins no significant reduction could be seen. In the sheep femoral vein removal of the endothelium also resulted in decrease of noradrenaline-induced contraction. It can be concluded that in the human saphenous vein the endothelium has a contraction facilitating effect in response to stimulation with noradrenaline. In varicose veins the endothelial-mediated enhancement of noradrenaline-induced vasoconstriction is reduced probably because of endothelial damage. This observation may be of importance in the pathogenesis of varicose veins.
Adherence of Staphylococcus epidermidis to pharyngeal epithelial cells as measured by [3H]-leucine-labelled bacteria was found to be a simple, objective and highly reproducible technique. Sublethal concentrations of cephalothin, rifampicin and vancomycin significantly reduced the bacterial adherence to epithelial cells, the effect being most marked with 1/2 MIC. Cloxacillin increased the adherence for one strain while it decreased it for the second. The effect was dose-related and the maximum reduction was observed when bacteria were grown with an antibiotic overnight.
A 17-year-old patient was found to have cyanosis. A right-to-left shunt was suspected clinically and confirmed by noninvasive techniques such as perfusion lung scan and contrast echocardiography. Angiography showed this shunt to be between the left pulmonary artery and the left atrium. We believe this to be the first report of a hitherto undescribed congenital anomaly.
Sixty asymptomatic patients (age 26 +/- 10 years) with chronic severe aortic regurgitation were followed prospectively for 2.4 +/- 1.4 years. Based on previous echocardiographic end-systolic dimension (ESD) and angiographic ejection fraction (EF) correlations, the cohort was divided into group A (21 patients) with ESD greater than or equal to 48 mm and group B (39 patients) with ESD less than 48 mm. Group B had a faster ESD progression (NS) and 19 crossed over to group A. Thirteen patients, all with ESD greater than 48 mm, reached designated end points. One died of cerebral embolism and 12 (age 31.4 +/- 10.6 years) required aortic valve replacement (AVR). Of these, 9 of 12 were asymptomatic and 11 of 12 had significant left ventricular dysfunction (LVD). The preoperative ESD of 51.9 +/- 4.1 mm fell to 38.4 +/- 3.6 mm (p less than 0.001) postoperatively and the EF of 43.7 +/- 4.16 increased to 64.9 +/- 5.9 (p less than 0.001). We found (1) the progression was faster than in other series; (2) ESD greater than 48 mm was associated with significant progression; and (3) patients with EF above 40% showed no residual LVD after AVR.
The role of the endothelium in the vasomotor control of veins was investigated in 14 isolated ring preparations of presumably normal saphenous veins obtained from vein grafts in connection with vascular surgery. The investigations were performed with the specimens mounted for recording isometric tension in organ baths. Paired rings were used, one normal and the other de-endothelialized by gentle rubbing. The responses to noradrenaline (10(-8)-2 X 10(-5) M), acetylcholine (10(-6) M) and 120 mM KCl solution were tested. After precontraction with 10(-7) M noradrenaline, acetylcholine at 10(-6) M did not induce cholinergic relaxation, but in the majority of experiments induced a further increase in tone. Maximal contraction with noradrenaline was significantly higher in normal compared to de-endothelialized vessels. Therefore, endothelium-derived relaxation as in arteries did not occur in human saphenous veins and the existence of an endothelial-derived contracting factor in response to acetylcholine and noradrenaline is a possibility.
Hemodynamic results after valve replacement surgery are well documented, but there are few follow-up studies on pulmonary function. Pulmonary function and hemodynamic studies were made, preoperatively, in 149 patients with predominant, mitral, aortic or combined mitral and aortic stenosis. A sequential postoperative follow-up of the pulmonary function was performed on 88 patients for as long as 125 wk after valve replacement. All patients had reduced preoperative values for forced vital capacity (FVC), single-breath carbon monoxide diffusing capacity (DLCO), forced expiratory volume in one second, peak expiratory flow rate, and maximal flow after exhalation of 75, 50, and 25% of FVC, and increased total airway resistance, resistance during expiration, and residual volume. The aortic group tended toward more normal values. There was significant correlation between the pulmonary function parameters and the hemodynamic data. In the early postoperative period (10 wk), deterioration of pulmonary function was significant in the aortic group and variable in the mitral and the combined groups; these responses correlated with preoperative hemodynamic and pulmonary function status. Between 10 to 125 wk, all patients showed progressive improvement, especially among those in the mitral group. Patients who died during or soon after mitral valve replacement were found to have significantly lower FVC and DLCO and significantly higher peripheral vascular resistance and cardiothoracic ratio. It is concluded that deterioration in pulmonary function is correlated to severity of cardiac dysfunction, and is reversible late after surgery, except in very advanced cases that have poor prognosis.
Explore the source record for details and available documents.
Left renal cell carcinoma extending into the right atrium was treated by angioinfarction, removal of right atrial tumour using cardiopulmonary bypass and ten days later abdominal radical nephrectomy and inferior vena cava thrombectomy. Twenty four months later the patient remains well with no evidence of tumour recurrence.
The adherence of bacteria to sutures used in cardiac surgery was studied by in vitro quantitative determination with [3H]-leucine-labeled Staphylococcus epidermidis, Staphylococcus aureus and Streptococcus sanguis. The adherence per unit area for staphylococci was least for monofilament polypropylene (Prolene), 3 times higher (p less than 0.05) for braided polyester (Mersiline) and greatest (10 times, p less than 0.005) for braided polyester sutures coated with polybutylate (Ethibond). Mean values for the adherence of streptococci were low for all the sutures. Sutures pretreated with human plasma showed a 12-37% increase in bacterial adherence. The cell surface hydrophobicity, surface charge and the haemagglutinating property of bacteria did not correlate with their adherence property. In view of these observations, it is suggested that: (a) the preferential adherence of staphylococci to intra-cardiac sutures may be one of the explanations for its being the commonest cause of early prosthetic valve endocarditis, (b) there is a need for a careful selection of sutures used in cardiac surgery and (c) the described in vitro assay for bacterial adherence may be used for monitoring the development of better designed sutures and the effect of incorporation of antibiotics in the sutures.
We report a case of infective endocarditis due to Cardiobacterium Hominis. This organism has rarely been recognized in the past as a human pathogen on the cardiac valves. This patient escaped early diagnosis, but he was successfully treated with parenteral ampicillin followed by elective aortic and mitral valve replacement. The bacteriological characteristics of this unusual cause of infective endocarditis are discussed and the world literature is reviewed.
We report a case of brucella endocarditis on a native aortic valve causing severe aortic regurgitation, uncontrolled heart failure and disseminated intravascular coagulopathy. The diagnosis was proven by positive serology, isolation of Brucella melitensis from preoperative blood cultures and excised valve. The patient was successfully treated with valve replacement and specific antibiotic therapy.
During the year 1983, 170 patients underwent open heart surgery; coronary bypass surgery in 50, valve replacement in 69, valve repair in 9 and congenital heart surgery in 47. Sternal wound infection was seen in 14 patients: 10 (5.8%) patients had minor infection, recovered with extended antibiotic therapy and local hygiene, and 4 (2.3%) patients had major wound infection which required debridement and resuturing of the wound, prolonged antibiotic treatment and hospitalization. However no one developed costochondral infection. Sternal wound infection was 6 times higher among coronary bypass patients (20%) than among patients with other types of open heart surgery (3.3%). Leg wound infection was observed in 7 (14%) patients, all minor. The prevalence of diabetics was 54% among coronary-bypass patients and 6.5% among non-coronary group. Wound infection was three times higher in diabetic--or obese patients than among non diabetic--or non obese patients. Infections were not related to age, sex, smoking habits or social class. The interval between catheterisation and operation, the preoperative stay in hospital, preoperative haemoglobin or albumin level, and the time during which the patient was on the ventilator and re-opening the chest for bleeding had no influence. A significantly higher incidence of infection in patients undergoing coronary artery surgery in addition to high prevalence of diabetic or obese patients was related to the longer duration of operation procedure and the coronary perfusion time.
A thorough investigation of a hypertensive 25 year old male was undertaken due to the finding of an absent right radial pulse. This work-up revealed widespread, largely asymptomatic arterial disease characterised by a combination of multiple sites of stenosis and occlusion, aneurysmal dilatation and extensive vessel wall calcification. The findings included a right renal artery stenosis, an abdominal aortic aneurysm and a splanchnic vasculature completely supplied by the inferior mesenteric artery. Consequently it was thought that a prolonged clamping time during the aortic repair would possibly result in ischemic injury. Therefore, the splanchnic organs were perfused by a paediatric oxygenator and pump during the aortic cross-clamping. This case report discusses the etiology of the disease and the technical aspects of splanchnic perfusion.