International Society of Cardiovascular Infectious Diseases Guidelines for the Diagnosis, Treatment and Prevention of Disseminated Mycobacterium chimaera Infection Following Cardiac Surgery with Cardiopulmonary Bypass

Mycobacterial infection-related morbidity and mortality in patients following cardiopulmonary bypass surgery is high and there is a growing need for a consensus-based expert opinion to provide international guidance for diagnosing, preventing and treating in these patients. In this document the International Society for Cardiovascular Infectious Diseases (ISCVID) covers aspects of prevention (field of hospital epidemiology), clinical management (infectious disease specialists, cardiac surgeons, ophthalmologists, others), laboratory diagnostics (microbiologists, molecular diagnostics), device management (perfusionists, cardiac surgeons) and public health aspects.

Ability to predict the development of surgical site infection in cardiac surgery using the Australian Clinical Risk Index versus the National Nosocomial Infections Surveillance-derived Risk Index

Surgical site infection (SSI) is a major infectious complication that increases mortality, morbidity, and healthcare costs. There are scores attempting to classify patients for calculating SSI risk. Our objectives were to validate the Australian Clinical Risk Index (ACRI) in a European population after cardiac surgery, comparing it against the National Nosocomial Infections Surveillance-derived risk index (NNIS) and analyzing the predictive power of ACRI for SSI in valvular patients. All the patients that who underwent cardiac surgery in a tertiary university hospital between 2011 and 2015 were analyzed. The patients were divided into valvular and coronary groups, excluding mixed patients. The ACRI score was validated in both groups and its ability to predict SSI was compared to the NNIS risk index. We analyzed 1,657 procedures. In the valvular patient group (n: 1119), a correlation between the ACRI score and SSI development (p < 0.05) was found; there was no such correlation with the NNIS index. The area under the receiver-operating characteristic curve (AUC) was 0.64 (confidence interval [CI] 95%, 0.5-0.7) for ACRI and 0.62 (95% CI, 0.5-0.7) for NNIS. In the coronary group (n: 281), there was a correlation between ACRI and SSI but no between NNIS and SSI. The ACRI AUC was 0.70 (95% CI, 0.5-0.8) and the NNIS AUC was 0.60 (95% CI, 0.4-0.7). The ACRI score has insufficient predictive power, although it predicts SSI development better than the NNIS index, fundamentally in coronary artery bypass grafting (CABG). Further studies analyzing determining factors are needed.

2016 Expert consensus document on prevention, diagnosis and treatment of short-term peripheral venous catheter-related infections in adult

The use of endovascular catheters is a routine practice in secondary and tertiary care level hospitals. Short peripheral catheters have been found to be associated with the risk of nosocomial bacteremia resulting in morbidity and mortality. Staphyloccus aureus is mostly associated with peripheral catheter insertion. This Consensus Document has been elaborated by a panel of experts of the Spanish Society of Cardiovascular Infections in cooperation with experts from the Spanish Society of Internal Medicine, Spanish Society of Chemotherapy and Spanish Society of Thoracic-Cardiovascular Surgery and aims at define and establish the norm for management of short duration peripheral vascular catheters. The document addresses the indications for insertion, catheter maintenance and registry, diagnosis and treatment of infection, indications for removal and stresses on continuous education as a driver for quality. Implementation of this norm will allow uniformity in usage thus minimizing the risk of infection and its complications.

An Update on Heart Transplantation in Human Immunodeficiency Virus-Infected Patients

Cardiovascular diseases have become a significant cause of morbidity in patients with human immunodeficiency virus (HIV) infection. Heart transplantation (HT) is a well-established treatment of end-stage heart failure (ESHF) and is performed in selected HIV-infected patients in developed countries. Few data are available on the prognosis of HIV-infected patients undergoing HT in the era of combined antiretroviral therapy (cART) because current evidence is limited to small retrospective cohorts, case series, and case reports. Many HT centers consider HIV infection to be a contraindication for HT; however, in the era of cART, HT recipients with HIV infection seem to achieve satisfactory outcomes without developing HIV-related events. Consequently, selected HIV-infected patients with ESHF who are taking effective cART should be considered candidates for HT. The present review provides epidemiological data on ESHF in HIV-infected patients from all published experience on HT in HIV-infected patients since the beginning of the epidemic. The practical management of these patients is discussed, with emphasis on the challenging issues that must be addressed in the pretransplant (including HIV criteria) and posttransplant periods. Finally, proposals are made for future management and research priorities.

Efficacy and safety of fosfomycin plus imipenem as rescue therapy for complicated bacteremia and endocarditis due to methicillin-resistant Staphylococcus aureus: a multicenter clinical trial

BACKGROUND

There is an urgent need for alternative rescue therapies in invasive infections caused by methicillin-resistant Staphylococcus aureus (MRSA). We assessed the clinical efficacy and safety of the combination of fosfomycin and imipenem as rescue therapy for MRSA infective endocarditis and complicated bacteremia.

METHODS

The trial was conducted between 2001 and 2010 in 3 Spanish hospitals. Adult patients with complicated MRSA bacteremia or endocarditis requiring rescue therapy were eligible for the study. Treatment with fosfomycin (2 g/6 hours IV) plus imipenem (1 g/6 hours IV) was started and monitored. The primary efficacy endpoints were percentage of sterile blood cultures at 72 hours and clinical success rate assessed at the test-of-cure visit (45 days after the end of therapy).

RESULTS

The combination was administered in 12 patients with endocarditis, 2 with vascular graft infection, and 2 with complicated bacteremia. Therapy had previously failed with vancomycin in 9 patients, daptomycin in 2, and sequential antibiotics in 5. Blood cultures were negative 72 hours after the first dose of the combination in all cases. The success rate was 69%, and only 1 of 5 deaths was related to the MRSA infection. Although the combination was safe in most patients (94%), a patient with liver cirrhosis died of multiorgan failure secondary to sodium overload. There were no episodes of breakthrough bacteremia or relapse.

CONCLUSIONS

Fosfomycin plus imipenem was an effective and safe combination when used as rescue therapy for complicated MRSA bloodstream infections and deserves further clinical evaluation as initial therapy in these infections.

Tricuspid valve surgery

INTRODUCTION

The tricuspid valve has been taken as a non-critical valve in terms of acute or late mortality in a number of conditions. Tricuspid functional regurgitation is a cause of late operations with an increased morbidity. A number of techniques have been described and used in clinical practice in the past forty years and include simple suture techniques and the use of support for annuloplasty with the use of different types of prosthetic rings. The experience accumulated over the years indicates that tricuspid annuloplasty is mandatory to improve late results, which are superior, in general, to replacement of the valve.

METHODS

The role of echocardiography in defining surgical planning, intraoperative results and follow-up is reviewed as echocardiography is a fundamental tool in cardiac surgery. Surgery for isolated lesions of the tricuspid valve has not received much attention and herein we report the results of the follow-up of a limited series of patients undergoing isolated tricuspid surgery.

RESULTS

The correlation between echocardiographic measurements and surgical measurements was confirmed and was helpful at the time of the confirmation of repair (r=0.53). Forty-seven patients (18 repair, 29 replacement) underwent isolated surgery. Results of isolated tricuspid repair seemed to be superior when compared to those of tricuspid replacement. Survival was 20.7% for tricuspid valve replacement (N=18) and 50% for tricuspid valve repair (N=29) (p=0.04). Freedom from reoperation was 94.4±5.4% for repair and 67.3±12.1% for replacement (p= 0.0011).

CONCLUSIONS

The tricuspid valve continues to be a surgical challenge.

Prosthetic valve endocarditis due to coagulase-negative staphylococci: findings from the International Collaboration on Endocarditis Merged Database

Infective endocarditis due to coagulase-negative staphylococci is increasingly recognized as a difficult-to-treat disease associated with poor outcome. The aim of this report is to describe the characteristics and outcome of patients with prosthetic valve endocarditis (PVE) due to coagulase-negative staphylococci versus those of patients with PVE due to Staphylococcus aureus and viridans streptococci. Patients were identified through the International Collaboration on Endocarditis Merged Database. A total of 54 cases of coagulase-negative staphylococci PVE, 58 cases of S. aureus PVE, and 63 cases of viridans-streptococci-related PVE were available for analysis. There was no difference between the three groups with respect to the type of valve involved or the rate of embolization. However, heart failure was encountered more frequently with coagulase-negative staphylococci (54%) than with either S. aureus (33%; p=0.03) or viridans streptococci (32%; p=0.02). In addition, valvular abscesses complicated 39% of infections due to coagulase-negative staphylococci compared with 22% of those due to S. aureus (p=0.06) and 6% of those due to viridans streptococci (p<0.001). Mortality was highest in patients with S. aureus and coagulase-negative staphylococcal endocarditis (47 and 36%, respectively; p=0.22) and was considerably lower in patients with viridans streptococcal endocarditis (p=0.002 compared to patients with coagulase-negative staphylococcal endocarditis). The results of this analysis demonstrate the aggressive nature of coagulase-negative staphylococcal PVE and the substantially greater morbidity and mortality associated with this infection compared to PVE caused by other pathogens.

Staphylococcus lugdunensis infective endocarditis: description of 10 cases and analysis of native valve, prosthetic valve, and pacemaker lead endocarditis clinical profiles

OBJECTIVE

To evaluate the incidence and the clinical and echocardiographic features of infective endocarditis (IE) caused by Staphylococcus lugdunensis and to identify the prognostic factors of surgery and mortality in this disease.

DESIGN

Prospective cohort study.

SETTING

Study at two centres (a tertiary care centre and a community hospital).

PATIENTS

10 patients with IE caused by S lugdunensis in 912 consecutive patients with IE between 1990 and 2003.

METHODS

Prospective study of consecutive patients carried out by the multidisciplinary team for diagnosis and treatment of IE from the study institutions. English, French, and Spanish literature was searched by computer under the terms "endocarditis" and "Staphylococcus lugdunensis" published between 1989 and December 2003.

MAIN OUTCOME MEASURES

Patient characteristics, echocardiographic findings, required surgery, and prognostic factors of mortality in left sided cases of IE.

RESULTS

10 cases of IE caused by S lugdunensis were identified at our institutions, representing 0.8% (four of 467), 1.5% (two of 135), and 7.8% (four of 51) of cases of native valve, prosthetic valve, and pacemaker lead endocarditis in the non-drug misusers. Native valve IE was present in four patients (two aortic, one mitral, and one pulmonary), prosthetic valve aortic IE in two patients, and pacemaker lead IE in the other four patients. All patients with left sided IE had serious complications (heart failure, periannular abscess formation, or shock) requiring surgery in 60% (three of five patients) of cases with an overall mortality rate of 80% (four of five patients). All patients with pacemaker IE underwent combined medical treatment and surgery, and mortality was 25% (one patient). In total 59 cases of IE caused by S lugdunensis were identified in a review of the literature. The combined analysis of these 69 cases showed that native valve IE (53 patients, 77%) is characterised by mitral valve involvement and frequent complications such as heart failure, abscess formation, and embolism. Surgery was needed in 51% of cases and mortality was 42%. Prosthetic valve endocarditis (nine of 60, 13%) predominated in the aortic position and was associated with abscess formation, required surgery, and high mortality (78%). Pacemaker lead IE (seven of 69, 10%) is associated with a better prognosis when antibiotic treatment is combined with surgery.

CONCLUSIONS

S lugdunensis IE is an uncommon cause of IE, involving mainly native left sided valves, and it is characterised by an aggressive clinical course. Mortality in left sided native valve IE is high but the prognosis has improved in recent years. Surgery has improved survival in left sided IE and, therefore, early surgery should always be considered. Prosthetic valve S lugdunensis IE carries an ominous prognosis.

Native valve endocarditis due to Candida glabrata treated without valvular replacement: a potential role for caspofungin in the induction and maintenance treatment

Conventional antifungal therapy for fungal endocarditis has been associated with a poor cure rate. Therefore, combined medical and surgical therapy has been recommended. However, new potent antifungal agents, such as echinocandins, could increase the medical options and, in some cases, avoid the need for surgery. We report a case of Candida endocarditis treated successfully without valve replacement with intravenous liposomal amphotericin B (total dose, 4 g) and intravenous caspofungin (a 100-mg loading dose followed by 50 mg per day for 8 weeks) as induction therapy and intravenous caspofungin (100 mg 3 times per week for 12 weeks) as maintenance therapy.

Infective endocarditis not related to intravenous drug abuse in HIV-1-infected patients: report of eight cases and review of the literature

OBJECTIVES

To add to the limited information on infective endocarditis (IE) not related to intravenous drug abuse (IVDA) in HIV-1-infected patients.

METHODS

We have reviewed the characteristics of eight cases of IE in non-IVDA HIV-1 infected patients diagnosed in our institution between 1979 and 1999 as well as cases in the literature.

RESULTS

All our patients were male, and the mean age was 44 years (range 29-64). HIV-1 risk factors were: homosexuality in five, heterosexuality in two, and the use of blood products in one. HIV stage C was found in six cases, and the median (range) CD4 cell count was 22/microL (4-274 cells/microL). IE was caused by Enterococcus faecalis in three cases, staphylococci in two cases, and Salmonella enteritidis, viridans group streptococci and Coxiella burnetii in one case each. Three patients acquired IE while in the hospital. All IE cases involved a native valve, and underlying valve disease was found in three patients. The aortic valve was the most frequently affected (five cases). Two patients underwent surgery, with a good outcome, and one patient died. Fourteen cases of IE not related to IVDA in HIV-1-infected patients were found in the literature review. The most common causative agents were Salmonella spp. and fungi (four cases each). Two patients had prosthetic valve IE, and the mitral valve was the most frequently affected (10 cases). The remaining clinical characteristics and the outcome were similar to those in the present series.

CONCLUSIONS

IE not related to IVDA is rare in HIV-1-infected patients. In more than half of the cases, IE develops in patients with advanced HIV-1 disease. A wide etiologic range is found, reflecting different clinical and environmental conditions. None of the patients who underwent surgery died, and the overall mortality rate was not higher than in non-HIV-1-infected patients with IE.

Aortocardiac fistulas complicating infective endocarditis

This study sought to determine the clinical and echocardiographic features, surgical approach, and outcome of patients with infective endocarditis complicated with aortocardiac fistulas among a series of 346 consecutive cases between 1988 and 1998. Nine patients (2%) were found to have aortocardiac fistulas complicating infective endocarditis caused by highly pyogenic pathogens (4 patients had ruptured abscesses of the right sinus of Valsalva, 3 had fistulous communications from the left coronary sinus, and 1 had a fistulized abscess in the noncoronary sinus). Mortality in these patients was very high (55%), even when surgery was attempted early in the course of the disease and reconstructive procedures were implemented.

Cardiovascular tissue banking in the non-cadaveric setting: ten-year experience of a university hospital-based bank with active organ donation program

BACKGROUND AND AIM OF THE STUDY

Today, transplantation of cardiovascular tissues is common practice, and tissue banking has become routine. Consequently, many institutions exist which carry out high-quality tissue banking.

METHODS

The Hospital Clinico of the University of Barcelona established its cardiovascular tissue bank in 1989. The bank follows international and national regulations, and functions as a non-profit-making organization. Organ and tissue donors are recruited by the Transplant Coordination unit, which works closely with the Catalonian Organ Transplant Network (OCAT) and the Spanish National Organ Transplantation Network (ONT). The hearts are removed during multi-organ donation and processed using aseptic techniques in a laminar flow hood. Hearts are only accepted from brain-dead multiorgan and non-beating-heart donors. The heart valves are dissected, decontaminated, cryopreserved in specific media and stored in liquid nitrogen at -196 degrees C under strict bacteriological and serological control.

RESULTS

Between 1989 and 1999, a series of 1,005 cardiovascular donors from within Spain was identified, from which 840 hearts were processed. After evaluation, 1,099 (65.4%) valves were cryopreserved, and 1,023 (61.5%) given clearance for implantation. In total, 534 aortic, 530 pulmonary, 33 mitral and two tricuspid valves were processed; ultimately 92.8% of aortic and 93.9% of pulmonary valves were accepted for clinical implantation. The rejection rate was 39.1%. Homografts were transported to their destination in dry ice in a cryogenic container. Overall, 608 valves were implanted at our own institution and at hospitals in Barcelona and Europe. Only two cases of complaint were received from implanting surgeons.

CONCLUSION

After ten years' experience, the degree of satisfaction of implanting surgeons appears to be adequate. Strict control of the entire tissue banking process has permitted the availability of high-quality homografts for clinical implantation.

Video-assisted cardioscopy for removal of primary left ventricular myxoma

Left ventricular myxoma is a rare benign cardiac tumor. Surgical excision is the treatment of choice and completeness of removal is mandatory to avoid late recurrence. A case is presented in which aortic transvalvular video-assisted cardioscopy was used to facilitate removal.

Six-year experience with cryopreserved mitral homografts in the treatment of tricuspid valve endocarditis in HIV-infected drug addicts

BACKGROUND AND AIM OF THE STUDY

In the past, valve homografts have been used in the treatment of aortic endocarditis. This report details our experience in tricuspid valve replacement using cryopreserved mitral homografts in HIV-positive drug addicts with infective endocarditis.

METHODS

Five HIV-1-infected drug addicts with active uncontrollable tricuspid valve endocarditis underwent tricuspid valve replacement with a cryopreserved mitral homograft.

RESULTS

There was no early mortality, and median follow up was 5 years (range: 1 to 6 years). One late mortality occurred as a result of heroin overdose. Three of the five patients developed six episodes of recurrent bacterial tricuspid endocarditis on the homograft; these were cured successfully with antibiotics. All survivors remain in NYHA functional class I. The latest transthoracic echocardiography examination showed mild, moderate or severe regurgitation in one, two and two patients, respectively. To date, neither homograft calcification nor rupture of the papillary muscle has been detected.

CONCLUSIONS

This novel technique is considered to be an adequate approach to these cases of uncontrollable infectious disease. Further episodes of valvular infection can be managed medically.

[Minimal access and minimally invasive coronary surgery]

After almost three decades of coronary artery surgery, there is a new interest in certain types of surgical interventions that may reduce the biological trauma through the elimination of cardiopulmonary bypass (CPB) and by practising through smaller thoracic incisions. Attempts are being made to demonstrate which operations can be performed without CPB or through minimal incisions. The operations without CPB are as old as coronary surgery itself, however they were abandoned because of the reliability and efficacy of doing coronary surgery in a bloodless and quiet field. Today a few series are already available showing that single-vessel coronary artery disease and an adequate patient selection seem to be, for the moment, fundamental issues in obtaining results as good as those obtained using conventional techniques and accesses. The main problem continues to be the quality of the anastomoses done with the heart beating or through small incisions that can make the work of the surgeon uncomfortable. Therefore, it is of utmost importance to collect postoperative angiographic data. In any case, we are in a very important moment in the history of coronary artery surgery as everybody is interested in evaluating the alternatives to reduce biological trauma by avoiding CPB and reducing the size of the incisions. These facts can have a positive influence on future results and in the reduction of the comprehensive costs of coronary artery surgery and therefore the actual impact of minimal invasive surgery.

Long-distance transportation of patients with a paracorporeal left ventricular assist device

Patients in cardiogenic shock refractory to basic medical therapy may require specialised assistance in a multispeciality environment distant to the institution where they are first admitted. In such situations, transportation of these critical patients may be difficult and involve many risks. Here we describe the case histories of two patients who underwent implantation of a paracorporeal left ventricular assist device and were transferred to specialised institutions for extended treatment. The distance of transportation was 400 km and the patients were transported by ambulance and helicopter. Some aspects of logistics and complexity of long-distance transportation are also commented on.

[Minimally invasive surgery of the mitral valve]

The technique of minimal access for mitral valve operations is commented on. A small right mediastinotomy is performed, which is a small right parasternal incision with resection of two costal cartilages. A correct exposure of the mitral valve is achieved through the right atrium and interatrial septum, allowing for adequate surgical correction.

Large-caliber cryopreserved arterial allografts in vascular reconstructive operations: early experience

Between October 1992 and June 1994, 16 patients (mean age, 55.6 years) underwent vascular reconstruction using cryopreserved arterial allografts. Aortoiliac aneurysms, vascular infections, and trauma accounted for the majority of case diagnoses. Twenty allografts were implanted. Two patients died in the hospital (12.5%) and 1 patient died 9 months after the operation. Early patency rate on angiography is 92.9%. Follow-up averages 8.2 months. Large-caliber cryopreserved arterial vascular allografts seem to provide satisfactory clinical results.

Acute thrombotic occlusion of the suprarenal aorta: importance of early diagnosis and treatment

Five patients with suprarenal aortic thrombosis were diagnosed and treated over the past 6 years. Attempts were made to establish aggressive medical and surgical treatment promptly. Three patients died in spite of immediate therapeutic measures. Two patients survived operation but one died 9 months later from myocardial infarction. The syndrome of high acute aortic occlusion is considered; attention is focused towards immediate diagnosis and treatment.

Monomelic hypertrophic osteoarthropathy secondary to aortic prosthesis infection

We describe a case of hypertrophic osteoarthropathy (HOA), exclusively located in the left lower leg and secondary to vascular prosthesis infection. Four years before, the patient underwent aortofemoral bifurcation grafting because of a ruptured aortic aneurysm. The investigations revealed prosthesis infection by Pseudomona aeruginosa and Bacteroides thetaiotamicron. The onset of HOA in a patient with a vascular prosthesis can help to achieve an early diagnosis of graft infection. The literature on this uncommon association is reviewed.

[Cardiac surgery in patients over 70. Its incidence and trends in Spain]

INTRODUCTION AND OBJECTIVES

During the last years elderly population has been growing in all the occidental world. Consequently the number of elderly patients undergoing cardiac surgery has increased. The aim of this work is to know whether this increase has also taken place in Spain.

METHODS

A survey among the different Units in the country was performed. The number and percentages of patients older than 70 years with coronary and valvular heart disease operated among 1991 and 1992 was analysed. Twenty-one of the 28 units replied (74%).

RESULTS

The percentage of coronary patients older than 70 years operated in 1991 was 15.61% and 19.20% in 1992, a statistically significant increase of 21.84% (p < 0.001). However, there was no significant increase in the number of elderly patients undergoing valvular surgery.

CONCLUSIONS

The influence of the elderly population on the activity in cardiac surgery is known to be significant; thus, a careful analysis of the health, social and economic implications seems to be mandatory.

Management of persistent tricuspid endocarditis with transplantation of cryopreserved mitral homografts

Transplantation of the human mitral valve in the tricuspid position for intractable infective endocarditis has been successfully performed in three young patients who were addicted to drugs. The maximum follow-up is 20 months. The rationale and historical basis for using this approach in the surgical treatment of patients with right-sided infective endocarditis is discussed and the appropriate literature reviewed. Because the technical aspects have been previously reported, this article can be considered an argument to renew past interest in atrioventricular valve replacement with fully biologic tissue of human origin.

[Postinfarction ventricular septal defect. Surgical approach by right ventriculotomy in 4 patients]

Ventricular septal defect secondary to myocardial infarction still have high mortality. Early and swift surgical repair is needed to obtain adequate results. Surgical exposure of defect through the infarcted left ventricle wall is the usual technique. Nevertheless right ventricular access to the interventricular septum has given excellent results on 4 of our patients. Our results are analyzed.

Cryopreserved homografts in aortic and mitral prosthetic endocarditis: expanding the use of biological tissues in complex cardiac infections

The case of a 27-year-old male heroin addict suffering from mitral and aortic prosthetic valve endocarditis is presented. Double valve re-replacement was performed using cryopreserved aortic homografts. Aortic root replacement with coronary re-implantation and intra-atrial valve implantation for mitral valve replacement were the techniques used. Despite the fatal outcome of this case, it clearly illustrates the possibilities of expanding the indications for combined complex replacement of heart valves by using fully biological tissue of human origin.

Tricuspid valve replacement using a mitral homograft. Surgical technique and initial results

Tricuspid valve replacement using a cryopreserved mitral valve homograft was carried out with success in three HIV positive drug addicts suffering from fungal or bacterial endocarditis. All three patients are alive and symptomless up to 16 months after surgery. This procedure is considered to be an alternative to other methods of tricuspid valve replacement if repair is not feasible. Further experience is needed to assess the long term performances of mitral homografts in the tricuspid position.

Overestimation of severity of mitral stenosis during cardiac catheterization due to a large left atrial thrombus

We report a case of mitral stenosis with a large left atrial thrombus which was obstructing pulmonary venous inflow where the conventional use of the pulmonary capillary wedge pressure as an approximation of the left atrial pressure during diagnostic cardiac catheterisation led to the over-estimation of the severity of mitral stenosis.

Ectopic thymoma: a case for median sternotomy for complete thymectomy

Thymomas are normally found in the superior mediastinum or the upper part of the anterior mediastinum. We report a case of thymoma arising in the inferior aspect of the anterior mediastinum. This case illustrates that thymic tissue may be found low in the anterior mediastinum and supports the practice of a median sternotomy approach for thorough mediastinal exploration in all cases of thymectomy.

Coronary artery bypass surgery in young patients

Coronary atherosclerosis is being increasingly observed in young patients. However results of surgery in such patients have so far been disappointing both in terms of operative mortality, symptomatic relief and long-term survival. Reasons given for this include the increased prevalence of risk factors in young patients and a higher incidence of graft occlusion. In the treatment of Asian patients, a further negative factor is the belief that coronary artery disease is more often diffuse and the vessels smaller. Between January 1987 and May 1991, a total of 66 patients under the age of 45 years at the time of surgery had coronary artery bypass grafting performed. The demographic, clinical, angiographic and operative data were analysed. Eighty-nine per cent of the patients were male and their racial distribution was 63% Chinese, 8% Malays, 26% Indians and 3% Others. Their mean age was 40.8 years. The presence of risk factors was high: 45.6% had hypertension; 34.8% were smokers; 21.2% had diabetes mellitus; and 12.1% had hyperlipidaemia. The main indication in these patients was either angina or a previous myocardial infarction (53%). There were no patients with perioperative infarction diagnosed by the presence of new Q wave. There was no hospital death. The stay of the patients ranged from 6 to 28 days with a mean of 10 days. Follow-up ranged from 3 to 54 months. There were no late deaths. It was concluded that there is a high incidence of risk factors among young patients with coronary artery disease, which follows the pattern of many other studies. The operative risk in these patients is low and morbidity is minimal.(ABSTRACT TRUNCATED AT 250 WORDS)

Early experiences of intra-operative trans-oesophageal echocardiography (TEE) in mitral valve repair

Whenever possible Mitral valve repair should be performed instead of Mitral valve replacement. It is important to assess the adequacy of the repair during the operation so that any corrective steps may be taken immediately. We present three cases of Mitral valve repair in which the intraoperative TEE was used to assess the adequacy of the repair. There was good correlation of the immediate post bypass TEE findings and early post operative transthoracic echocardiographic findings. Intraoperative TEE is a useful tool in the early assessment of Mitral Valve Repair.

Mitral valve repair in patients on chronic hemodialysis

Two cases of successful mitral valve repair in patients on chronic hemodialysis are presented. We stress that valve repair is preferable to valve replacement whenever feasible because of improved left ventricular function, reduced complication rate, and freedom from anticoagulation. This especially applies to patients on chronic hemodialysis as they have impaired immunological function, are subjected to repeated fistula punctures with possible bacteremia, and are more susceptible to early calcification and degeneration of tissue valves.

Intravascular hemolysis after mitral valve repair: a word of caution

The case of a young patient who presented with severe hemolysis after mitral valve repair is presented. Valve repair included chordal shortening, transposition of chordae tendinae, and annular remodelling using a Duran flexible ring. Reoperation and valve replacement were required to control hemolytic anemia. The possible mechanisms leading to such an uncommon complication after plastic repair of the mitral valve are commented on. The scanty literature concerned is reviewed.

[Aortic valve replacement by a pulmonary homograft]

Minor experience still exists in our country with regard to the use of valve homografts in cardiac surgery. Only a few implantations have been performed in cases of right ventricular outflow tract reconstruction in addition to our own experience in cases of infective endocarditis of the aortic valve. We present a case of aortic valve replacement by using an antibiotic-sterilized fresh pulmonary valve autograft. The case is described and the possible advantages of the use of pulmonary allografts in the aortic position are discussed.

Delayed sternal closure for life-threatening complications in cardiac operations: an update

Over a 7-year-period, 25 patients had delayed sternal closure after open heart operations out of 34 patients whose sternum was not closed. The indications were extreme cardiac dilatation and uncontrollable mediastinal hemorrhage. This represented a 1.79% incidence in the overall open heart surgical experience at our unit. Sternal closure was performed at a mean of 2.64 days after the initial operation. Eighteen patients (52.9%) left the hospital alive and well, representing a 72% survival rate among patients undergoing delayed sternal closure. No mediastinal or fatal infection developed and only 1 patient had late superficial wound infection after delayed sternal closure. We conclude that delayed sternal closure is an effective method to treat severe complications after cardiac operations.

[An alternative approach in the surgical treatment of infectious endocarditis. The fresh antibiotic-sterilized aortic valve homograft]

Following the pioneering work of Ross and Barratt-Boyes, there is currently a strong evidence based on long-term follow-up data that valve homografts are the best valve substitutes in the aortic position. Currently there exists a renewed interest in the use of fresh and cryopreserved homografts as we know that homografts show a prolonged durability together with the lack of thromboembolic complications. Here we present the case histories of 3 patients undergoing aortic valve replacement by fresh homografts sterilized in antibiotic solution. The underlying pathology was infective endocarditis in all 3 patients, a disease that is considered the ideal indication for homograft implantation. Technical details at the time of implantation, their advantages with regard to other replacements devices and the whole process of procurement, manipulation and preservation are commented on.

Myocardial revascularisation in patients with carotid artery disease

From January 1987 to December 1989, 80 patients with carotid bruit and/or history of transient ischaemic attack/stroke underwent digital subtraction angiography (DSA) prior to consideration for coronary artery bypass graft. Thirty-eight patients (Group I) out of the 80 had coronary artery bypass graft done with postoperative stroke in five (13.2%); this contrasted with a group of 320 patients (Group II) without cerebrovascular disease who underwent coronary artery bypass graft during the same period with postoperative stroke in two cases (0.63%) (p less than 0.0005). Carotid artery stenosis was noted on the DSA in 66% of Group I patients, with significant disease (greater than 70% occlusion) in 15%, while the study was normal in 34% of cases. Combined carotid endarterectomy and coronary artery bypass graft was done in five of Group I patients, with postoperative stroke in one; this was the only one among the stroke patients with significant carotid disease. All strokes, except in one patient, resolved within one to 6 1/2 months. These results suggest that the risk of stroke after coronary artery bypass graft is increased in patients with carotid bruit or history of transient ischaemic attack/stroke and in the presence of established carotid artery disease. The place of combined carotid endarterectomy and coronary artery bypass graft in these cases remains to be determined.

[Replacement of the aortic root and ascending aorta with a fresh antibiotic-sterilized homograft]

The case of a 53-year-old male suffering from aortic stenosis and aneurysm of the ascending aorta treated by aortic root replacement with a fresh antibiotic-sterilized aortic homograft is presented. The technique and indications are commented on, focusing attention in the scanty results available in the literature with regard to this technique. We support the use of homografts in aortic root replacement in selected cases.

Obstruction and recanalization of the ureter during embryonic development

Major controversies still exist regarding the terminology, the etiology and the pathogenesis of congenital obstructive diseases of the ureter. To try to provide some additional information to this controversial subject, a comparative study of ureteral development in rat and human embryos, using light and electron microscopy, has been performed. During fetal development we observed and demonstrated the existence of obstructive phenomena, both at the level of the ureterovesical junction (Chwalla's membrane) and along the ureter. At the end of the embryonic period, the ureter undergoes a physiologic recanalization process.

Combined resection of hepatoblastoma and intracaval right atrial extension with profound hypothermia and circulatory arrest

Hepatoblastoma is an uncommon liver neoplasm in children but its intraatrial extension through the inferior vena cava is extremely rare. The case described is a 3-year-old boy in whom profound hypothermia and circulatory arrest were used to resect a hepatoblastoma and its extension to the right atrium. This technique allows maximal resection and relief of venous obstruction from atrial extension of hepatoblastoma.